In Mediatek SOCs, the uart can support DMA function.
Base on DMA engine formwork, we add the DMA code to support uart. And put the code under drivers/dma.
This series contains document bindings, Kconfig to control the function enable or not,
device tree including interrupt and dma device node, the code of UART DM
Changes compared to v1:
-mian revised file, 8250_mtk_dma.c
--parameters renamed for standard
--remove atomic operation
Long Cheng (4):
dt-bindings: dma: uart: add uart dma bindings
dmaengine: mtk_uart_dma: add Mediatek uart DMA support
serial: 8250-mtk: add uart DMA support
arm: dts: mt2701: add uart APDMA to device tree
.../devicetree/bindings/dma/8250_mtk_dma.txt | 33 +
arch/arm64/boot/dts/mediatek/mt2712e.dtsi | 50 ++
drivers/dma/mediatek/8250_mtk_dma.c | 894 ++++++++++++++++++++
drivers/dma/mediatek/Kconfig | 11 +
drivers/dma/mediatek/Makefile | 1 +
drivers/tty/serial/8250/8250_mtk.c | 210 ++++-
6 files changed, 1198 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/dma/8250_mtk_dma.txt
create mode 100644 drivers/dma/mediatek/8250_mtk_dma.c
In DMA engine framework, add 8250 mtk dma to support it.
Signed-off-by: Long Cheng <[email protected]>
---
drivers/dma/mediatek/8250_mtk_dma.c | 894 +++++++++++++++++++++++++++++++++++
drivers/dma/mediatek/Kconfig | 11 +
drivers/dma/mediatek/Makefile | 1 +
3 files changed, 906 insertions(+)
create mode 100644 drivers/dma/mediatek/8250_mtk_dma.c
diff --git a/drivers/dma/mediatek/8250_mtk_dma.c b/drivers/dma/mediatek/8250_mtk_dma.c
new file mode 100644
index 0000000..3454679
--- /dev/null
+++ b/drivers/dma/mediatek/8250_mtk_dma.c
@@ -0,0 +1,894 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Mediatek 8250 DMA driver.
+ *
+ * Copyright (c) 2018 MediaTek Inc.
+ * Author: Long Cheng <[email protected]>
+ */
+
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of_dma.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/pm_runtime.h>
+#include <linux/iopoll.h>
+
+#include "../virt-dma.h"
+
+#define MTK_APDMA_DEFAULT_REQUESTS 127
+#define MTK_APDMA_CHANNELS (CONFIG_SERIAL_8250_NR_UARTS * 2)
+
+#define VFF_EN_B BIT(0)
+#define VFF_STOP_B BIT(0)
+#define VFF_FLUSH_B BIT(0)
+#define VFF_4G_SUPPORT_B BIT(0)
+#define VFF_RX_INT_EN0_B BIT(0) /*rx valid size >= vff thre*/
+#define VFF_RX_INT_EN1_B BIT(1)
+#define VFF_TX_INT_EN_B BIT(0) /*tx left size >= vff thre*/
+#define VFF_WARM_RST_B BIT(0)
+#define VFF_RX_INT_FLAG_CLR_B (BIT(0) | BIT(1))
+#define VFF_TX_INT_FLAG_CLR_B 0
+#define VFF_STOP_CLR_B 0
+#define VFF_FLUSH_CLR_B 0
+#define VFF_INT_EN_CLR_B 0
+#define VFF_4G_SUPPORT_CLR_B 0
+
+/* interrupt trigger level for tx */
+#define VFF_TX_THRE(n) ((n) * 7 / 8)
+/* interrupt trigger level for rx */
+#define VFF_RX_THRE(n) ((n) * 3 / 4)
+
+#define MTK_DMA_RING_SIZE 0xffffU
+/* invert this bit when wrap ring head again*/
+#define MTK_DMA_RING_WRAP 0x10000U
+
+#define VFF_INT_FLAG 0x00
+#define VFF_INT_EN 0x04
+#define VFF_EN 0x08
+#define VFF_RST 0x0c
+#define VFF_STOP 0x10
+#define VFF_FLUSH 0x14
+#define VFF_ADDR 0x1c
+#define VFF_LEN 0x24
+#define VFF_THRE 0x28
+#define VFF_WPT 0x2c
+#define VFF_RPT 0x30
+/*TX: the buffer size HW can read. RX: the buffer size SW can read.*/
+#define VFF_VALID_SIZE 0x3c
+/*TX: the buffer size SW can write. RX: the buffer size HW can write.*/
+#define VFF_LEFT_SIZE 0x40
+#define VFF_DEBUG_STATUS 0x50
+#define VFF_4G_SUPPORT 0x54
+
+struct mtk_dmadev {
+ struct dma_device ddev;
+ void __iomem *mem_base[MTK_APDMA_CHANNELS];
+ spinlock_t lock; /* dma dev lock */
+ struct tasklet_struct task;
+ struct list_head pending;
+ struct clk *clk;
+ unsigned int dma_requests;
+ bool support_33bits;
+ unsigned int dma_irq[MTK_APDMA_CHANNELS];
+ struct mtk_chan *ch[MTK_APDMA_CHANNELS];
+};
+
+struct mtk_chan {
+ struct virt_dma_chan vc;
+ struct list_head node;
+ struct dma_slave_config cfg;
+ void __iomem *base;
+ struct mtk_dma_desc *desc;
+
+ bool stop;
+ bool requested;
+
+ unsigned int dma_sig;
+ unsigned int dma_ch;
+ unsigned int sgidx;
+ unsigned int remain_size;
+ unsigned int rx_ptr;
+};
+
+struct mtk_dma_sg {
+ dma_addr_t addr;
+ unsigned int en; /* number of elements (24-bit) */
+ unsigned int fn; /* number of frames (16-bit) */
+};
+
+struct mtk_dma_desc {
+ struct virt_dma_desc vd;
+ enum dma_transfer_direction dir;
+
+ unsigned int sglen;
+ struct mtk_dma_sg sg[0];
+};
+
+static bool mtk_dma_filter_fn(struct dma_chan *chan, void *param);
+static struct of_dma_filter_info mtk_dma_info = {
+ .filter_fn = mtk_dma_filter_fn,
+};
+
+static inline struct mtk_dmadev *to_mtk_dma_dev(struct dma_device *d)
+{
+ return container_of(d, struct mtk_dmadev, ddev);
+}
+
+static inline struct mtk_chan *to_mtk_dma_chan(struct dma_chan *c)
+{
+ return container_of(c, struct mtk_chan, vc.chan);
+}
+
+static inline struct mtk_dma_desc *to_mtk_dma_desc
+ (struct dma_async_tx_descriptor *t)
+{
+ return container_of(t, struct mtk_dma_desc, vd.tx);
+}
+
+static void mtk_dma_chan_write(struct mtk_chan *c,
+ unsigned int reg, unsigned int val)
+{
+ writel(val, c->base + reg);
+}
+
+static unsigned int mtk_dma_chan_read(struct mtk_chan *c, unsigned int reg)
+{
+ return readl(c->base + reg);
+}
+
+static void mtk_dma_desc_free(struct virt_dma_desc *vd)
+{
+ struct dma_chan *chan = vd->tx.chan;
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+
+ kfree(c->desc);
+ c->desc = NULL;
+}
+
+static int mtk_dma_clk_enable(struct mtk_dmadev *mtkd)
+{
+ int ret;
+
+ ret = clk_prepare_enable(mtkd->clk);
+ if (ret) {
+ dev_err(mtkd->ddev.dev, "Couldn't enable the clock\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static void mtk_dma_clk_disable(struct mtk_dmadev *mtkd)
+{
+ clk_disable_unprepare(mtkd->clk);
+}
+
+static void mtk_dma_remove_virt_list(dma_cookie_t cookie,
+ struct virt_dma_chan *vc)
+{
+ struct virt_dma_desc *vd;
+
+ if (list_empty(&vc->desc_issued) == 0) {
+ list_for_each_entry(vd, &vc->desc_issued, node) {
+ if (cookie == vd->tx.cookie) {
+ INIT_LIST_HEAD(&vc->desc_issued);
+ break;
+ }
+ }
+ }
+}
+
+static void mtk_dma_tx_flush(struct dma_chan *chan)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+
+ if (mtk_dma_chan_read(c, VFF_FLUSH) == 0U)
+ mtk_dma_chan_write(c, VFF_FLUSH, VFF_FLUSH_B);
+}
+
+static void mtk_dma_tx_write(struct dma_chan *chan)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ unsigned int txcount = c->remain_size;
+ unsigned int len, send, left, wpt, wrap;
+
+ len = mtk_dma_chan_read(c, VFF_LEN);
+
+ while ((left = mtk_dma_chan_read(c, VFF_LEFT_SIZE)) > 0U) {
+ if (c->remain_size == 0U)
+ break;
+ send = min(left, c->remain_size);
+ wpt = mtk_dma_chan_read(c, VFF_WPT);
+ wrap = wpt & MTK_DMA_RING_WRAP ? 0U : MTK_DMA_RING_WRAP;
+
+ if ((wpt & (len - 1U)) + send < len)
+ mtk_dma_chan_write(c, VFF_WPT, wpt + send);
+ else
+ mtk_dma_chan_write(c, VFF_WPT,
+ ((wpt + send) & (len - 1U))
+ | wrap);
+
+ c->remain_size -= send;
+ }
+
+ if (txcount != c->remain_size) {
+ mtk_dma_chan_write(c, VFF_INT_EN, VFF_TX_INT_EN_B);
+ mtk_dma_tx_flush(chan);
+ }
+}
+
+static void mtk_dma_start_tx(struct mtk_chan *c)
+{
+ if (mtk_dma_chan_read(c, VFF_LEFT_SIZE) == 0U)
+ mtk_dma_chan_write(c, VFF_INT_EN, VFF_TX_INT_EN_B);
+ else
+ mtk_dma_tx_write(&c->vc.chan);
+
+ c->stop = false;
+}
+
+static void mtk_dma_get_rx_size(struct mtk_chan *c)
+{
+ unsigned int rx_size = mtk_dma_chan_read(c, VFF_LEN);
+ unsigned int rdptr, wrptr, wrreg, rdreg, count;
+
+ rdreg = mtk_dma_chan_read(c, VFF_RPT);
+ wrreg = mtk_dma_chan_read(c, VFF_WPT);
+ rdptr = rdreg & MTK_DMA_RING_SIZE;
+ wrptr = wrreg & MTK_DMA_RING_SIZE;
+ count = ((rdreg ^ wrreg) & MTK_DMA_RING_WRAP) ?
+ (wrptr + rx_size - rdptr) : (wrptr - rdptr);
+
+ c->remain_size = count;
+ c->rx_ptr = rdptr;
+
+ mtk_dma_chan_write(c, VFF_RPT, wrreg);
+}
+
+static void mtk_dma_start_rx(struct mtk_chan *c)
+{
+ struct dma_chan *chan = &c->vc.chan;
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
+ struct mtk_dma_desc *d = c->desc;
+
+ if (mtk_dma_chan_read(c, VFF_VALID_SIZE) == 0U)
+ return;
+
+ if (d && d->vd.tx.cookie != 0) {
+ mtk_dma_get_rx_size(c);
+ mtk_dma_remove_virt_list(d->vd.tx.cookie, &c->vc);
+ vchan_cookie_complete(&d->vd);
+ } else {
+ spin_lock(&mtkd->lock);
+ if (list_empty(&mtkd->pending))
+ list_add_tail(&c->node, &mtkd->pending);
+ spin_unlock(&mtkd->lock);
+ tasklet_schedule(&mtkd->task);
+ }
+}
+
+static void mtk_dma_reset(struct mtk_chan *c)
+{
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(c->vc.chan.device);
+ u32 status;
+ int ret;
+
+ mtk_dma_chan_write(c, VFF_ADDR, 0);
+ mtk_dma_chan_write(c, VFF_THRE, 0);
+ mtk_dma_chan_write(c, VFF_LEN, 0);
+ mtk_dma_chan_write(c, VFF_RST, VFF_WARM_RST_B);
+
+ ret = readx_poll_timeout(readl,
+ c->base + VFF_EN,
+ status, status == 0, 10, 100);
+ if (ret) {
+ dev_err(c->vc.chan.device->dev,
+ "dma reset: fail, timeout\n");
+ return;
+ }
+
+ if (c->cfg.direction == DMA_DEV_TO_MEM)
+ mtk_dma_chan_write(c, VFF_RPT, 0);
+ else if (c->cfg.direction == DMA_MEM_TO_DEV)
+ mtk_dma_chan_write(c, VFF_WPT, 0);
+
+ if (mtkd->support_33bits)
+ mtk_dma_chan_write(c, VFF_4G_SUPPORT, VFF_4G_SUPPORT_CLR_B);
+}
+
+static void mtk_dma_stop(struct mtk_chan *c)
+{
+ u32 status;
+ int ret;
+
+ mtk_dma_chan_write(c, VFF_FLUSH, VFF_FLUSH_CLR_B);
+ /* Wait for flush */
+ ret = readx_poll_timeout(readl,
+ c->base + VFF_FLUSH,
+ status,
+ (status & VFF_FLUSH_B) != VFF_FLUSH_B,
+ 10, 100);
+ if (ret)
+ dev_err(c->vc.chan.device->dev,
+ "dma stop: polling FLUSH fail, DEBUG=0x%x\n",
+ mtk_dma_chan_read(c, VFF_DEBUG_STATUS));
+
+ /*set stop as 1 -> wait until en is 0 -> set stop as 0*/
+ mtk_dma_chan_write(c, VFF_STOP, VFF_STOP_B);
+ ret = readx_poll_timeout(readl,
+ c->base + VFF_EN,
+ status, status == 0, 10, 100);
+ if (ret)
+ dev_err(c->vc.chan.device->dev,
+ "dma stop: polling VFF_EN fail, DEBUG=0x%x\n",
+ mtk_dma_chan_read(c, VFF_DEBUG_STATUS));
+
+ mtk_dma_chan_write(c, VFF_STOP, VFF_STOP_CLR_B);
+ mtk_dma_chan_write(c, VFF_INT_EN, VFF_INT_EN_CLR_B);
+
+ if (c->cfg.direction == DMA_DEV_TO_MEM)
+ mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_RX_INT_FLAG_CLR_B);
+ else
+ mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_TX_INT_FLAG_CLR_B);
+
+ c->stop = true;
+}
+
+/*
+ * This callback schedules all pending channels. We could be more
+ * clever here by postponing allocation of the real DMA channels to
+ * this point, and freeing them when our virtual channel becomes idle.
+ *
+ * We would then need to deal with 'all channels in-use'
+ */
+static void mtk_dma_sched(unsigned long data)
+{
+ struct mtk_dmadev *mtkd = (struct mtk_dmadev *)data;
+ struct virt_dma_desc *vd;
+ struct mtk_chan *c;
+ dma_cookie_t cookie;
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ spin_lock_irq(&mtkd->lock);
+ list_splice_tail_init(&mtkd->pending, &head);
+ spin_unlock_irq(&mtkd->lock);
+
+ if (!list_empty(&head)) {
+ c = list_first_entry(&head, struct mtk_chan, node);
+ cookie = c->vc.chan.cookie;
+
+ spin_lock_irqsave(&c->vc.lock, flags);
+ if (c->cfg.direction == DMA_DEV_TO_MEM) {
+ list_del_init(&c->node);
+ mtk_dma_start_rx(c);
+ } else if (c->cfg.direction == DMA_MEM_TO_DEV) {
+ vd = vchan_find_desc(&c->vc, cookie);
+ c->desc = to_mtk_dma_desc(&vd->tx);
+ list_del_init(&c->node);
+ mtk_dma_start_tx(c);
+ }
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+ }
+}
+
+static int mtk_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ int ret = -EBUSY;
+
+ pm_runtime_get_sync(mtkd->ddev.dev);
+
+ if (!mtkd->ch[c->dma_ch]) {
+ c->base = mtkd->mem_base[c->dma_ch];
+ mtkd->ch[c->dma_ch] = c;
+ ret = 1;
+ }
+ c->requested = false;
+ mtk_dma_reset(c);
+
+ return ret;
+}
+
+static void mtk_dma_free_chan_resources(struct dma_chan *chan)
+{
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+
+ if (c->requested) {
+ c->requested = false;
+ free_irq(mtkd->dma_irq[c->dma_ch], chan);
+ }
+
+ tasklet_kill(&mtkd->task);
+ tasklet_kill(&c->vc.task);
+
+ c->base = NULL;
+ mtkd->ch[c->dma_ch] = NULL;
+ vchan_free_chan_resources(&c->vc);
+
+ dev_dbg(mtkd->ddev.dev, "freeing channel for %u\n", c->dma_sig);
+ c->dma_sig = 0;
+
+ pm_runtime_put_sync(mtkd->ddev.dev);
+}
+
+static enum dma_status mtk_dma_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ enum dma_status ret;
+ unsigned long flags;
+
+ if (!txstate)
+ return DMA_ERROR;
+
+ ret = dma_cookie_status(chan, cookie, txstate);
+ spin_lock_irqsave(&c->vc.lock, flags);
+ if (ret == DMA_IN_PROGRESS) {
+ c->rx_ptr = mtk_dma_chan_read(c, VFF_RPT) & MTK_DMA_RING_SIZE;
+ dma_set_residue(txstate, c->rx_ptr);
+ } else if (ret == DMA_COMPLETE && c->cfg.direction == DMA_DEV_TO_MEM) {
+ dma_set_residue(txstate, c->remain_size);
+ } else {
+ dma_set_residue(txstate, 0);
+ }
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+
+ return ret;
+}
+
+static struct dma_async_tx_descriptor *mtk_dma_prep_slave_sg
+ (struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sglen, enum dma_transfer_direction dir,
+ unsigned long tx_flags, void *context)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ struct scatterlist *sgent;
+ struct mtk_dma_desc *d;
+ struct mtk_dma_sg *sg;
+ unsigned int size, i, j, en;
+
+ en = 1;
+
+ if ((dir != DMA_DEV_TO_MEM) &&
+ (dir != DMA_MEM_TO_DEV)) {
+ dev_err(chan->device->dev, "bad direction\n");
+ return NULL;
+ }
+
+ /* Now allocate and setup the descriptor. */
+ d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC);
+ if (!d)
+ return NULL;
+
+ d->dir = dir;
+
+ j = 0;
+ for_each_sg(sgl, sgent, sglen, i) {
+ d->sg[j].addr = sg_dma_address(sgent);
+ d->sg[j].en = en;
+ d->sg[j].fn = sg_dma_len(sgent) / en;
+ j++;
+ }
+
+ d->sglen = j;
+
+ if (dir == DMA_MEM_TO_DEV) {
+ for (size = i = 0; i < d->sglen; i++) {
+ sg = &d->sg[i];
+ size += sg->en * sg->fn;
+ }
+ c->remain_size = size;
+ }
+
+ return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
+}
+
+static void mtk_dma_issue_pending(struct dma_chan *chan)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ struct virt_dma_desc *vd;
+ struct mtk_dmadev *mtkd;
+ dma_cookie_t cookie;
+ unsigned long flags;
+
+ spin_lock_irqsave(&c->vc.lock, flags);
+ if (c->cfg.direction == DMA_DEV_TO_MEM) {
+ cookie = c->vc.chan.cookie;
+ mtkd = to_mtk_dma_dev(chan->device);
+ if (vchan_issue_pending(&c->vc) && !c->desc) {
+ vd = vchan_find_desc(&c->vc, cookie);
+ c->desc = to_mtk_dma_desc(&vd->tx);
+ }
+ } else if (c->cfg.direction == DMA_MEM_TO_DEV) {
+ cookie = c->vc.chan.cookie;
+ if (vchan_issue_pending(&c->vc) && !c->desc) {
+ vd = vchan_find_desc(&c->vc, cookie);
+ c->desc = to_mtk_dma_desc(&vd->tx);
+ mtk_dma_start_tx(c);
+ }
+ }
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+}
+
+static irqreturn_t mtk_dma_rx_interrupt(int irq, void *dev_id)
+{
+ struct dma_chan *chan = (struct dma_chan *)dev_id;
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&c->vc.lock, flags);
+ mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_RX_INT_FLAG_CLR_B);
+
+ mtk_dma_start_rx(c);
+
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t mtk_dma_tx_interrupt(int irq, void *dev_id)
+{
+ struct dma_chan *chan = (struct dma_chan *)dev_id;
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ struct mtk_dma_desc *d = c->desc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&c->vc.lock, flags);
+ if (c->remain_size != 0U) {
+ list_add_tail(&c->node, &mtkd->pending);
+ tasklet_schedule(&mtkd->task);
+ } else {
+ mtk_dma_remove_virt_list(d->vd.tx.cookie, &c->vc);
+ vchan_cookie_complete(&d->vd);
+ }
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+
+ mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_TX_INT_FLAG_CLR_B);
+
+ return IRQ_HANDLED;
+}
+
+static int mtk_dma_slave_config(struct dma_chan *chan,
+ struct dma_slave_config *cfg)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(c->vc.chan.device);
+ int ret;
+
+ c->cfg = *cfg;
+
+ if (cfg->direction == DMA_DEV_TO_MEM) {
+ unsigned int rx_len = cfg->src_addr_width * 1024;
+
+ mtk_dma_chan_write(c, VFF_ADDR, cfg->src_addr);
+ mtk_dma_chan_write(c, VFF_LEN, rx_len);
+ mtk_dma_chan_write(c, VFF_THRE, VFF_RX_THRE(rx_len));
+ mtk_dma_chan_write(c,
+ VFF_INT_EN, VFF_RX_INT_EN0_B
+ | VFF_RX_INT_EN1_B);
+ mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_RX_INT_FLAG_CLR_B);
+ mtk_dma_chan_write(c, VFF_EN, VFF_EN_B);
+
+ if (!c->requested) {
+ c->requested = true;
+ ret = request_irq(mtkd->dma_irq[c->dma_ch],
+ mtk_dma_rx_interrupt,
+ IRQF_TRIGGER_NONE,
+ KBUILD_MODNAME, chan);
+ if (ret < 0) {
+ dev_err(chan->device->dev, "Can't request rx dma IRQ\n");
+ return -EINVAL;
+ }
+ }
+ } else if (cfg->direction == DMA_MEM_TO_DEV) {
+ unsigned int tx_len = cfg->dst_addr_width * 1024;
+
+ mtk_dma_chan_write(c, VFF_ADDR, cfg->dst_addr);
+ mtk_dma_chan_write(c, VFF_LEN, tx_len);
+ mtk_dma_chan_write(c, VFF_THRE, VFF_TX_THRE(tx_len));
+ mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_TX_INT_FLAG_CLR_B);
+ mtk_dma_chan_write(c, VFF_EN, VFF_EN_B);
+
+ if (!c->requested) {
+ c->requested = true;
+ ret = request_irq(mtkd->dma_irq[c->dma_ch],
+ mtk_dma_tx_interrupt,
+ IRQF_TRIGGER_NONE,
+ KBUILD_MODNAME, chan);
+ if (ret < 0) {
+ dev_err(chan->device->dev, "Can't request tx dma IRQ\n");
+ return -EINVAL;
+ }
+ }
+ }
+
+ if (mtkd->support_33bits)
+ mtk_dma_chan_write(c, VFF_4G_SUPPORT, VFF_4G_SUPPORT_B);
+
+ if (mtk_dma_chan_read(c, VFF_EN) != VFF_EN_B) {
+ dev_err(chan->device->dev,
+ "config dma dir[%d] fail\n", cfg->direction);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int mtk_dma_terminate_all(struct dma_chan *chan)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&c->vc.lock, flags);
+ list_del_init(&c->node);
+ mtk_dma_stop(c);
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+
+ return 0;
+}
+
+static int mtk_dma_device_pause(struct dma_chan *chan)
+{
+ /* just for check caps pass */
+ return -EINVAL;
+}
+
+static int mtk_dma_device_resume(struct dma_chan *chan)
+{
+ /* just for check caps pass */
+ return -EINVAL;
+}
+
+static void mtk_dma_free(struct mtk_dmadev *mtkd)
+{
+ tasklet_kill(&mtkd->task);
+ while (list_empty(&mtkd->ddev.channels) == 0) {
+ struct mtk_chan *c = list_first_entry(&mtkd->ddev.channels,
+ struct mtk_chan, vc.chan.device_node);
+
+ list_del(&c->vc.chan.device_node);
+ tasklet_kill(&c->vc.task);
+ devm_kfree(mtkd->ddev.dev, c);
+ }
+}
+
+static const struct of_device_id mtk_uart_dma_match[] = {
+ { .compatible = "mediatek,mt6577-uart-dma", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, mtk_uart_dma_match);
+
+static int mtk_apdma_probe(struct platform_device *pdev)
+{
+ struct mtk_dmadev *mtkd;
+ struct resource *res;
+ struct mtk_chan *c;
+ unsigned int i;
+ int rc;
+
+ mtkd = devm_kzalloc(&pdev->dev, sizeof(*mtkd), GFP_KERNEL);
+ if (!mtkd)
+ return -ENOMEM;
+
+ for (i = 0; i < MTK_APDMA_CHANNELS; i++) {
+ res = platform_get_resource(pdev, IORESOURCE_MEM, i);
+ if (!res)
+ return -ENODEV;
+ mtkd->mem_base[i] = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mtkd->mem_base[i]))
+ return PTR_ERR(mtkd->mem_base[i]);
+ }
+
+ for (i = 0; i < MTK_APDMA_CHANNELS; i++) {
+ mtkd->dma_irq[i] = platform_get_irq(pdev, i);
+ if ((int)mtkd->dma_irq[i] < 0) {
+ dev_err(&pdev->dev, "failed to get IRQ[%d]\n", i);
+ return -EINVAL;
+ }
+ }
+
+ mtkd->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(mtkd->clk)) {
+ dev_err(&pdev->dev, "No clock specified\n");
+ return PTR_ERR(mtkd->clk);
+ }
+
+ if (of_property_read_bool(pdev->dev.of_node, "dma-33bits")) {
+ dev_info(&pdev->dev, "Support dma 33bits\n");
+ mtkd->support_33bits = true;
+ }
+
+ if (mtkd->support_33bits)
+ rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(33));
+ else
+ rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+ if (rc)
+ return rc;
+
+ dma_cap_set(DMA_SLAVE, mtkd->ddev.cap_mask);
+ mtkd->ddev.device_alloc_chan_resources = mtk_dma_alloc_chan_resources;
+ mtkd->ddev.device_free_chan_resources = mtk_dma_free_chan_resources;
+ mtkd->ddev.device_tx_status = mtk_dma_tx_status;
+ mtkd->ddev.device_issue_pending = mtk_dma_issue_pending;
+ mtkd->ddev.device_prep_slave_sg = mtk_dma_prep_slave_sg;
+ mtkd->ddev.device_config = mtk_dma_slave_config;
+ mtkd->ddev.device_pause = mtk_dma_device_pause;
+ mtkd->ddev.device_resume = mtk_dma_device_resume;
+ mtkd->ddev.device_terminate_all = mtk_dma_terminate_all;
+ mtkd->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE);
+ mtkd->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE);
+ mtkd->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ mtkd->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
+ mtkd->ddev.dev = &pdev->dev;
+ INIT_LIST_HEAD(&mtkd->ddev.channels);
+ INIT_LIST_HEAD(&mtkd->pending);
+
+ spin_lock_init(&mtkd->lock);
+ tasklet_init(&mtkd->task, mtk_dma_sched, (unsigned long)mtkd);
+
+ mtkd->dma_requests = MTK_APDMA_DEFAULT_REQUESTS;
+ if (of_property_read_u32(pdev->dev.of_node,
+ "dma-requests", &mtkd->dma_requests)) {
+ dev_info(&pdev->dev,
+ "Missing dma-requests property, using %u.\n",
+ MTK_APDMA_DEFAULT_REQUESTS);
+ }
+
+ for (i = 0; i < MTK_APDMA_CHANNELS; i++) {
+ c = devm_kzalloc(mtkd->ddev.dev, sizeof(*c), GFP_KERNEL);
+ if (!c)
+ goto err_no_dma;
+
+ c->vc.desc_free = mtk_dma_desc_free;
+ vchan_init(&c->vc, &mtkd->ddev);
+ INIT_LIST_HEAD(&c->node);
+ }
+
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_set_active(&pdev->dev);
+
+ rc = dma_async_device_register(&mtkd->ddev);
+ if (rc)
+ goto rpm_disable;
+
+ platform_set_drvdata(pdev, mtkd);
+
+ if (pdev->dev.of_node) {
+ mtk_dma_info.dma_cap = mtkd->ddev.cap_mask;
+
+ /* Device-tree DMA controller registration */
+ rc = of_dma_controller_register(pdev->dev.of_node,
+ of_dma_simple_xlate,
+ &mtk_dma_info);
+ if (rc)
+ goto dma_remove;
+ }
+
+ return rc;
+
+dma_remove:
+ dma_async_device_unregister(&mtkd->ddev);
+rpm_disable:
+ pm_runtime_disable(&pdev->dev);
+err_no_dma:
+ mtk_dma_free(mtkd);
+ return rc;
+}
+
+static int mtk_apdma_remove(struct platform_device *pdev)
+{
+ struct mtk_dmadev *mtkd = platform_get_drvdata(pdev);
+
+ if (pdev->dev.of_node)
+ of_dma_controller_free(pdev->dev.of_node);
+
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_put_noidle(&pdev->dev);
+
+ dma_async_device_unregister(&mtkd->ddev);
+
+ mtk_dma_free(mtkd);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_dma_suspend(struct device *dev)
+{
+ struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
+
+ if (!pm_runtime_suspended(dev))
+ mtk_dma_clk_disable(mtkd);
+
+ return 0;
+}
+
+static int mtk_dma_resume(struct device *dev)
+{
+ int ret;
+ struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
+
+ if (!pm_runtime_suspended(dev)) {
+ ret = mtk_dma_clk_enable(mtkd);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int mtk_dma_runtime_suspend(struct device *dev)
+{
+ struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
+
+ mtk_dma_clk_disable(mtkd);
+
+ return 0;
+}
+
+static int mtk_dma_runtime_resume(struct device *dev)
+{
+ int ret;
+ struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
+
+ ret = mtk_dma_clk_enable(mtkd);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops mtk_dma_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(mtk_dma_suspend, mtk_dma_resume)
+ SET_RUNTIME_PM_OPS(mtk_dma_runtime_suspend,
+ mtk_dma_runtime_resume, NULL)
+};
+
+static struct platform_driver mtk_dma_driver = {
+ .probe = mtk_apdma_probe,
+ .remove = mtk_apdma_remove,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .pm = &mtk_dma_pm_ops,
+ .of_match_table = of_match_ptr(mtk_uart_dma_match),
+ },
+};
+
+static bool mtk_dma_filter_fn(struct dma_chan *chan, void *param)
+{
+ if (chan->device->dev->driver == &mtk_dma_driver.driver) {
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ unsigned int req = *(unsigned int *)param;
+
+ if (req <= mtkd->dma_requests) {
+ c->dma_sig = req;
+ c->dma_ch = req;
+ return true;
+ }
+ }
+ return false;
+}
+
+module_platform_driver(mtk_dma_driver);
+
+MODULE_DESCRIPTION("MediaTek UART APDMA Controller Driver");
+MODULE_AUTHOR("Long Cheng <[email protected]>");
+MODULE_LICENSE("GPL v2");
+
diff --git a/drivers/dma/mediatek/Kconfig b/drivers/dma/mediatek/Kconfig
index 27bac0b..bef436e 100644
--- a/drivers/dma/mediatek/Kconfig
+++ b/drivers/dma/mediatek/Kconfig
@@ -1,4 +1,15 @@
+config DMA_MTK_UART
+ tristate "MediaTek SoCs APDMA support for UART"
+ depends on OF
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+ help
+ Support for the UART DMA engine found on MediaTek MTK SoCs.
+ when 8250 mtk uart is enabled, and if you want to using DMA,
+ you can enable the config. the DMA engine just only be used
+ with MediaTek Socs.
+
config MTK_HSDMA
tristate "MediaTek High-Speed DMA controller support"
depends on ARCH_MEDIATEK || COMPILE_TEST
diff --git a/drivers/dma/mediatek/Makefile b/drivers/dma/mediatek/Makefile
index 6e778f8..2f2efd9 100644
--- a/drivers/dma/mediatek/Makefile
+++ b/drivers/dma/mediatek/Makefile
@@ -1 +1,2 @@
+obj-$(CONFIG_DMA_MTK_UART) += 8250_mtk_dma.o
obj-$(CONFIG_MTK_HSDMA) += mtk-hsdma.o
--
1.7.9.5
1. add uart APDMA controller device node
2. add uart 0/1/2/3/4/5 DMA function
Signed-off-by: Long Cheng <[email protected]>
---
arch/arm64/boot/dts/mediatek/mt2712e.dtsi | 50 +++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
diff --git a/arch/arm64/boot/dts/mediatek/mt2712e.dtsi b/arch/arm64/boot/dts/mediatek/mt2712e.dtsi
index 976d92a..a59728b 100644
--- a/arch/arm64/boot/dts/mediatek/mt2712e.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt2712e.dtsi
@@ -300,6 +300,9 @@
interrupts = <GIC_SPI 127 IRQ_TYPE_LEVEL_LOW>;
clocks = <&baud_clk>, <&sys_clk>;
clock-names = "baud", "bus";
+ dmas = <&apdma 10
+ &apdma 11>;
+ dma-names = "tx", "rx";
status = "disabled";
};
@@ -378,6 +381,38 @@
status = "disabled";
};
+ apdma: dma-controller@11000400 {
+ compatible = "mediatek,mt2712-uart-dma",
+ "mediatek,mt6577-uart-dma";
+ reg = <0 0x11000400 0 0x80>,
+ <0 0x11000480 0 0x80>,
+ <0 0x11000500 0 0x80>,
+ <0 0x11000580 0 0x80>,
+ <0 0x11000600 0 0x80>,
+ <0 0x11000680 0 0x80>,
+ <0 0x11000700 0 0x80>,
+ <0 0x11000780 0 0x80>,
+ <0 0x11000800 0 0x80>,
+ <0 0x11000880 0 0x80>,
+ <0 0x11000900 0 0x80>,
+ <0 0x11000980 0 0x80>;
+ interrupts = <GIC_SPI 103 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 104 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 105 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 106 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 107 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 108 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 109 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 110 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 111 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 112 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 113 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 114 IRQ_TYPE_LEVEL_LOW>;
+ clocks = <&pericfg CLK_PERI_AP_DMA>;
+ clock-names = "apdma";
+ #dma-cells = <1>;
+ };
+
uart0: serial@11002000 {
compatible = "mediatek,mt2712-uart",
"mediatek,mt6577-uart";
@@ -385,6 +420,9 @@
interrupts = <GIC_SPI 91 IRQ_TYPE_LEVEL_LOW>;
clocks = <&baud_clk>, <&sys_clk>;
clock-names = "baud", "bus";
+ dmas = <&apdma 0
+ &apdma 1>;
+ dma-names = "tx", "rx";
status = "disabled";
};
@@ -395,6 +433,9 @@
interrupts = <GIC_SPI 92 IRQ_TYPE_LEVEL_LOW>;
clocks = <&baud_clk>, <&sys_clk>;
clock-names = "baud", "bus";
+ dmas = <&apdma 2
+ &apdma 3>;
+ dma-names = "tx", "rx";
status = "disabled";
};
@@ -405,6 +446,9 @@
interrupts = <GIC_SPI 93 IRQ_TYPE_LEVEL_LOW>;
clocks = <&baud_clk>, <&sys_clk>;
clock-names = "baud", "bus";
+ dmas = <&apdma 4
+ &apdma 5>;
+ dma-names = "tx", "rx";
status = "disabled";
};
@@ -415,6 +459,9 @@
interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_LOW>;
clocks = <&baud_clk>, <&sys_clk>;
clock-names = "baud", "bus";
+ dmas = <&apdma 6
+ &apdma 7>;
+ dma-names = "tx", "rx";
status = "disabled";
};
@@ -629,6 +676,9 @@
interrupts = <GIC_SPI 126 IRQ_TYPE_LEVEL_LOW>;
clocks = <&baud_clk>, <&sys_clk>;
clock-names = "baud", "bus";
+ dmas = <&apdma 8
+ &apdma 9>;
+ dma-names = "tx", "rx";
status = "disabled";
};
--
1.7.9.5
Modify uart register to support DMA function.
Signed-off-by: Long Cheng <[email protected]>
---
drivers/tty/serial/8250/8250_mtk.c | 210 +++++++++++++++++++++++++++++++++++-
1 file changed, 209 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index dd5e1ce..1da73e8 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -14,6 +14,10 @@
#include <linux/pm_runtime.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
+#include <linux/console.h>
+#include <linux/dma-mapping.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
#include "8250.h"
@@ -22,12 +26,172 @@
#define UART_MTK_SAMPLE_POINT 0x0b /* Sample point register */
#define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */
+#define MTK_UART_DMA_EN 0x13 /* DMA Enable register */
+#define MTK_UART_DMA_EN_TX 0x2
+#define MTK_UART_DMA_EN_RX 0x5
+
+#define MTK_UART_TX_SIZE UART_XMIT_SIZE
+#define MTK_UART_RX_SIZE 0x8000
+#define MTK_UART_TX_TRIGGER 1
+#define MTK_UART_RX_TRIGGER MTK_UART_RX_SIZE
+
+#ifdef CONFIG_SERIAL_8250_DMA
+enum dma_rx_status {
+ DMA_RX_START = 0,
+ DMA_RX_RUNNING = 1,
+ DMA_RX_SHUTDOWN = 2,
+};
+#endif
+
struct mtk8250_data {
int line;
+ unsigned int rx_pos;
struct clk *uart_clk;
struct clk *bus_clk;
+ struct uart_8250_dma *dma;
+#ifdef CONFIG_SERIAL_8250_DMA
+ enum dma_rx_status rx_status;
+#endif
};
+#ifdef CONFIG_SERIAL_8250_DMA
+static void mtk8250_rx_dma(struct uart_8250_port *up);
+
+static void mtk8250_dma_rx_complete(void *param)
+{
+ struct uart_8250_port *up = param;
+ struct uart_8250_dma *dma = up->dma;
+ struct mtk8250_data *data = up->port.private_data;
+ struct tty_port *tty_port = &up->port.state->port;
+ struct dma_tx_state state;
+ unsigned char *ptr;
+ int copied;
+
+ dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr,
+ dma->rx_size, DMA_FROM_DEVICE);
+
+ dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+
+ if (data->rx_status == DMA_RX_SHUTDOWN)
+ return;
+
+ if ((data->rx_pos + state.residue) <= dma->rx_size) {
+ ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
+ copied = tty_insert_flip_string(tty_port, ptr, state.residue);
+ } else {
+ ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
+ copied = tty_insert_flip_string(tty_port, ptr,
+ dma->rx_size - data->rx_pos);
+ ptr = (unsigned char *)(dma->rx_buf);
+ copied += tty_insert_flip_string(tty_port, ptr,
+ data->rx_pos + state.residue - dma->rx_size);
+ }
+ up->port.icount.rx += copied;
+
+ tty_flip_buffer_push(tty_port);
+
+ mtk8250_rx_dma(up);
+}
+
+static void mtk8250_rx_dma(struct uart_8250_port *up)
+{
+ struct uart_8250_dma *dma = up->dma;
+ struct mtk8250_data *data = up->port.private_data;
+ struct dma_async_tx_descriptor *desc;
+ struct dma_tx_state state;
+
+ desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
+ dma->rx_size, DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc) {
+ pr_err("failed to prepare rx slave single\n");
+ return;
+ }
+
+ desc->callback = mtk8250_dma_rx_complete;
+ desc->callback_param = up;
+
+ dma->rx_cookie = dmaengine_submit(desc);
+
+ dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+ data->rx_pos = state.residue;
+
+ dma_sync_single_for_device(dma->rxchan->device->dev, dma->rx_addr,
+ dma->rx_size, DMA_FROM_DEVICE);
+
+ dma_async_issue_pending(dma->rxchan);
+}
+
+static void mtk8250_dma_enable(struct uart_8250_port *up)
+{
+ struct uart_8250_dma *dma = up->dma;
+ struct mtk8250_data *data = up->port.private_data;
+ int lcr = serial_in(up, UART_LCR);
+
+ if (data->rx_status != DMA_RX_START)
+ return;
+
+ dma->rxconf.direction = DMA_DEV_TO_MEM;
+ dma->rxconf.src_addr_width = dma->rx_size / 1024;
+ dma->rxconf.src_addr = dma->rx_addr;
+
+ dma->txconf.direction = DMA_MEM_TO_DEV;
+ dma->txconf.dst_addr_width = MTK_UART_TX_SIZE / 1024;
+ dma->txconf.dst_addr = dma->tx_addr;
+
+ serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
+ UART_FCR_CLEAR_XMIT);
+ serial_out(up, MTK_UART_DMA_EN,
+ MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX);
+
+ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+ serial_out(up, UART_EFR, UART_EFR_ECB);
+ serial_out(up, UART_LCR, lcr);
+
+ if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0)
+ pr_err("failed to configure rx dma channel\n");
+ if (dmaengine_slave_config(dma->txchan, &dma->txconf) != 0)
+ pr_err("failed to configure tx dma channel\n");
+
+ data->rx_status = DMA_RX_RUNNING;
+ data->rx_pos = 0;
+ mtk8250_rx_dma(up);
+}
+#endif
+
+static int mtk8250_startup(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_8250_DMA
+ struct uart_8250_port *up = up_to_u8250p(port);
+ struct mtk8250_data *data = port->private_data;
+
+ /* disable DMA for console */
+ if (uart_console(port))
+ up->dma = NULL;
+
+ if (up->dma) {
+ data->rx_status = DMA_RX_START;
+ uart_circ_clear(&port->state->xmit);
+ }
+#endif
+ memset(&port->icount, 0, sizeof(port->icount));
+
+ return serial8250_do_startup(port);
+}
+
+static void mtk8250_shutdown(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_8250_DMA
+ struct uart_8250_port *up = up_to_u8250p(port);
+ struct mtk8250_data *data = port->private_data;
+
+ if (up->dma)
+ data->rx_status = DMA_RX_SHUTDOWN;
+#endif
+
+ return serial8250_do_shutdown(port);
+}
+
static void
mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
@@ -36,6 +200,17 @@ struct mtk8250_data {
unsigned long flags;
unsigned int baud, quot;
+#ifdef CONFIG_SERIAL_8250_DMA
+ if (up->dma) {
+ if (uart_console(port)) {
+ devm_kfree(up->port.dev, up->dma);
+ up->dma = NULL;
+ } else {
+ mtk8250_dma_enable(up);
+ }
+ }
+#endif
+
serial8250_do_set_termios(port, termios, old);
/*
@@ -143,9 +318,20 @@ static int __maybe_unused mtk8250_runtime_resume(struct device *dev)
pm_runtime_put_sync_suspend(port->dev);
}
+#ifdef CONFIG_SERIAL_8250_DMA
+static bool mtk8250_dma_filter(struct dma_chan *chan, void *param)
+{
+ return false;
+}
+#endif
+
static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
struct mtk8250_data *data)
{
+#ifdef CONFIG_SERIAL_8250_DMA
+ int dmacnt;
+#endif
+
data->uart_clk = devm_clk_get(&pdev->dev, "baud");
if (IS_ERR(data->uart_clk)) {
/*
@@ -162,7 +348,23 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
}
data->bus_clk = devm_clk_get(&pdev->dev, "bus");
- return PTR_ERR_OR_ZERO(data->bus_clk);
+ if (IS_ERR(data->bus_clk))
+ return PTR_ERR(data->bus_clk);
+
+ data->dma = NULL;
+#ifdef CONFIG_SERIAL_8250_DMA
+ dmacnt = of_property_count_strings(pdev->dev.of_node, "dma-names");
+ if (dmacnt == 2) {
+ data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma),
+ GFP_KERNEL);
+ data->dma->fn = mtk8250_dma_filter;
+ data->dma->rx_size = MTK_UART_RX_SIZE;
+ data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER;
+ data->dma->txconf.dst_maxburst = MTK_UART_TX_TRIGGER;
+ }
+#endif
+
+ return 0;
}
static int mtk8250_probe(struct platform_device *pdev)
@@ -204,8 +406,14 @@ static int mtk8250_probe(struct platform_device *pdev)
uart.port.iotype = UPIO_MEM32;
uart.port.regshift = 2;
uart.port.private_data = data;
+ uart.port.shutdown = mtk8250_shutdown;
+ uart.port.startup = mtk8250_startup;
uart.port.set_termios = mtk8250_set_termios;
uart.port.uartclk = clk_get_rate(data->uart_clk);
+#ifdef CONFIG_SERIAL_8250_DMA
+ if (data->dma)
+ uart.dma = data->dma;
+#endif
/* Disable Rate Fix function */
writel(0x0, uart.port.membase +
--
1.7.9.5
add uart dma bindings
Signed-off-by: Long Cheng <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
---
.../devicetree/bindings/dma/8250_mtk_dma.txt | 33 ++++++++++++++++++++
1 file changed, 33 insertions(+)
create mode 100644 Documentation/devicetree/bindings/dma/8250_mtk_dma.txt
diff --git a/Documentation/devicetree/bindings/dma/8250_mtk_dma.txt b/Documentation/devicetree/bindings/dma/8250_mtk_dma.txt
new file mode 100644
index 0000000..3fe0961
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/8250_mtk_dma.txt
@@ -0,0 +1,33 @@
+* Mediatek UART APDMA Controller
+
+Required properties:
+- compatible should contain:
+ * "mediatek,mt2712-uart-dma" for MT2712 compatible APDMA
+ * "mediatek,mt6577-uart-dma" for MT6577 and all of the above
+
+- reg: The base address of the APDMA register bank.
+
+- interrupts: A single interrupt specifier.
+
+- clocks : Must contain an entry for each entry in clock-names.
+ See ../clocks/clock-bindings.txt for details.
+- clock-names: The APDMA clock for register accesses
+
+Examples:
+
+ apdma: dma-controller@11000380 {
+ compatible = "mediatek,mt2712-uart-dma";
+ reg = <0 0x11000380 0 0x400>;
+ interrupts = <GIC_SPI 63 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 64 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 65 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 66 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 67 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 68 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 69 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_SPI 70 IRQ_TYPE_LEVEL_LOW>;
+ clocks = <&pericfg CLK_PERI_AP_DMA>;
+ clock-names = "apdma";
+ #dma-cells = <1>;
+ };
+
--
1.7.9.5
On Wed, Dec 05, 2018 at 04:42:56PM +0800, Long Cheng wrote:
> In Mediatek SOCs, the uart can support DMA function.
> Base on DMA engine formwork, we add the DMA code to support uart. And put the code under drivers/dma.
>
> This series contains document bindings, Kconfig to control the function enable or not,
> device tree including interrupt and dma device node, the code of UART DM
I've queued up patches 1 and 3 from this series in my tty tree, thanks.
greg k-h
Hi Greg,
On 05-12-18, 11:03, Greg Kroah-Hartman wrote:
> On Wed, Dec 05, 2018 at 04:42:56PM +0800, Long Cheng wrote:
> > In Mediatek SOCs, the uart can support DMA function.
> > Base on DMA engine formwork, we add the DMA code to support uart. And put the code under drivers/dma.
> >
> > This series contains document bindings, Kconfig to control the function enable or not,
> > device tree including interrupt and dma device node, the code of UART DM
>
> I've queued up patches 1 and 3 from this series in my tty tree, thanks.
Do you mind not taking patch 2, I would like that to go thru dmaengine
tree
Thanks
--
~Vinod
On Wed, Dec 05, 2018 at 10:01:33PM +0530, Vinod Koul wrote:
> Hi Greg,
>
> On 05-12-18, 11:03, Greg Kroah-Hartman wrote:
> > On Wed, Dec 05, 2018 at 04:42:56PM +0800, Long Cheng wrote:
> > > In Mediatek SOCs, the uart can support DMA function.
> > > Base on DMA engine formwork, we add the DMA code to support uart. And put the code under drivers/dma.
> > >
> > > This series contains document bindings, Kconfig to control the function enable or not,
> > > device tree including interrupt and dma device node, the code of UART DM
> >
> > I've queued up patches 1 and 3 from this series in my tty tree, thanks.
>
> Do you mind not taking patch 2, I would like that to go thru dmaengine
> tree
Like I said, I only took patches 1 and 3...
.
On Wed, Dec 5, 2018 at 1:31 AM Long Cheng <[email protected]> wrote:
>
> In DMA engine framework, add 8250 mtk dma to support it.
>
> Signed-off-by: Long Cheng <[email protected]>
> ---
> drivers/dma/mediatek/8250_mtk_dma.c | 894 +++++++++++++++++++++++++++++++++++
> drivers/dma/mediatek/Kconfig | 11 +
> drivers/dma/mediatek/Makefile | 1 +
> 3 files changed, 906 insertions(+)
> create mode 100644 drivers/dma/mediatek/8250_mtk_dma.c
>
> diff --git a/drivers/dma/mediatek/8250_mtk_dma.c b/drivers/dma/mediatek/8250_mtk_dma.c
> new file mode 100644
> index 0000000..3454679
> --- /dev/null
> +++ b/drivers/dma/mediatek/8250_mtk_dma.c
> @@ -0,0 +1,894 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Mediatek 8250 DMA driver.
> + *
> + * Copyright (c) 2018 MediaTek Inc.
> + * Author: Long Cheng <[email protected]>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/dmaengine.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/of_dma.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/iopoll.h>
> +
> +#include "../virt-dma.h"
> +
> +#define MTK_APDMA_DEFAULT_REQUESTS 127
> +#define MTK_APDMA_CHANNELS (CONFIG_SERIAL_8250_NR_UARTS * 2)
> +
> +#define VFF_EN_B BIT(0)
> +#define VFF_STOP_B BIT(0)
> +#define VFF_FLUSH_B BIT(0)
> +#define VFF_4G_SUPPORT_B BIT(0)
> +#define VFF_RX_INT_EN0_B BIT(0) /*rx valid size >= vff thre*/
> +#define VFF_RX_INT_EN1_B BIT(1)
> +#define VFF_TX_INT_EN_B BIT(0) /*tx left size >= vff thre*/
> +#define VFF_WARM_RST_B BIT(0)
> +#define VFF_RX_INT_FLAG_CLR_B (BIT(0) | BIT(1))
> +#define VFF_TX_INT_FLAG_CLR_B 0
> +#define VFF_STOP_CLR_B 0
> +#define VFF_FLUSH_CLR_B 0
> +#define VFF_INT_EN_CLR_B 0
> +#define VFF_4G_SUPPORT_CLR_B 0
> +
> +/* interrupt trigger level for tx */
> +#define VFF_TX_THRE(n) ((n) * 7 / 8)
> +/* interrupt trigger level for rx */
> +#define VFF_RX_THRE(n) ((n) * 3 / 4)
> +
> +#define MTK_DMA_RING_SIZE 0xffffU
> +/* invert this bit when wrap ring head again*/
> +#define MTK_DMA_RING_WRAP 0x10000U
> +
> +#define VFF_INT_FLAG 0x00
> +#define VFF_INT_EN 0x04
> +#define VFF_EN 0x08
> +#define VFF_RST 0x0c
> +#define VFF_STOP 0x10
> +#define VFF_FLUSH 0x14
> +#define VFF_ADDR 0x1c
> +#define VFF_LEN 0x24
> +#define VFF_THRE 0x28
> +#define VFF_WPT 0x2c
> +#define VFF_RPT 0x30
> +/*TX: the buffer size HW can read. RX: the buffer size SW can read.*/
> +#define VFF_VALID_SIZE 0x3c
> +/*TX: the buffer size SW can write. RX: the buffer size HW can write.*/
> +#define VFF_LEFT_SIZE 0x40
> +#define VFF_DEBUG_STATUS 0x50
> +#define VFF_4G_SUPPORT 0x54
> +
> +struct mtk_dmadev {
> + struct dma_device ddev;
> + void __iomem *mem_base[MTK_APDMA_CHANNELS];
> + spinlock_t lock; /* dma dev lock */
> + struct tasklet_struct task;
> + struct list_head pending;
> + struct clk *clk;
> + unsigned int dma_requests;
> + bool support_33bits;
> + unsigned int dma_irq[MTK_APDMA_CHANNELS];
> + struct mtk_chan *ch[MTK_APDMA_CHANNELS];
> +};
> +
> +struct mtk_chan {
> + struct virt_dma_chan vc;
> + struct list_head node;
> + struct dma_slave_config cfg;
> + void __iomem *base;
> + struct mtk_dma_desc *desc;
> +
> + bool stop;
> + bool requested;
> +
> + unsigned int dma_sig;
the member can be removed as no real user would refer to it
> + unsigned int dma_ch;
a chan_id is already included in struct dma_chan, we can reuse it
> + unsigned int sgidx;
the member also can be removed as no real user would refer to it
> + unsigned int remain_size;
The member remain_size seems unnecessary data to maintain a channel.
The virtual channel struct virt_dma_chan already provide the way to
manage all descriptors you're operating on, you should reuse related
functions to virt_dma_chan first.
Or if you mean remain_size is about the remaining size of current
descriptor, and then putting into struct mtk_dma_desc would be better.
> + unsigned int rx_ptr;
> +};
> +
> +struct mtk_dma_sg {
> + dma_addr_t addr;
> + unsigned int en; /* number of elements (24-bit) */
> + unsigned int fn; /* number of frames (16-bit) */
> +};
> +
> +struct mtk_dma_desc {
> + struct virt_dma_desc vd;
> + enum dma_transfer_direction dir;
> +
> + unsigned int sglen;
> + struct mtk_dma_sg sg[0];
> +};
> +
> +static bool mtk_dma_filter_fn(struct dma_chan *chan, void *param);
> +static struct of_dma_filter_info mtk_dma_info = {
> + .filter_fn = mtk_dma_filter_fn,
> +};
> +
> +static inline struct mtk_dmadev *to_mtk_dma_dev(struct dma_device *d)
> +{
> + return container_of(d, struct mtk_dmadev, ddev);
> +}
> +
> +static inline struct mtk_chan *to_mtk_dma_chan(struct dma_chan *c)
> +{
> + return container_of(c, struct mtk_chan, vc.chan);
> +}
> +
> +static inline struct mtk_dma_desc *to_mtk_dma_desc
> + (struct dma_async_tx_descriptor *t)
> +{
> + return container_of(t, struct mtk_dma_desc, vd.tx);
> +}
> +
> +static void mtk_dma_chan_write(struct mtk_chan *c,
> + unsigned int reg, unsigned int val)
> +{
> + writel(val, c->base + reg);
> +}
> +
> +static unsigned int mtk_dma_chan_read(struct mtk_chan *c, unsigned int reg)
> +{
> + return readl(c->base + reg);
> +}
> +
> +static void mtk_dma_desc_free(struct virt_dma_desc *vd)
> +{
> + struct dma_chan *chan = vd->tx.chan;
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> +
> + kfree(c->desc);
> + c->desc = NULL;
> +}
> +
> +static int mtk_dma_clk_enable(struct mtk_dmadev *mtkd)
> +{
> + int ret;
> +
> + ret = clk_prepare_enable(mtkd->clk);
> + if (ret) {
> + dev_err(mtkd->ddev.dev, "Couldn't enable the clock\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void mtk_dma_clk_disable(struct mtk_dmadev *mtkd)
> +{
> + clk_disable_unprepare(mtkd->clk);
> +}
> +
> +static void mtk_dma_remove_virt_list(dma_cookie_t cookie,
> + struct virt_dma_chan *vc)
> +{
> + struct virt_dma_desc *vd;
> +
> + if (list_empty(&vc->desc_issued) == 0) {
> + list_for_each_entry(vd, &vc->desc_issued, node) {
> + if (cookie == vd->tx.cookie) {
> + INIT_LIST_HEAD(&vc->desc_issued);
generally, we don't force initialze the list desc_issued. Instead,
when each descriptor is completed, we need to move each descriptor
from the list desc_issued to the list desc_completed.
> + break;
> + }
> + }
> + }
> +}
> +
> +static void mtk_dma_tx_flush(struct dma_chan *chan)
> +{
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> +
> + if (mtk_dma_chan_read(c, VFF_FLUSH) == 0U)
> + mtk_dma_chan_write(c, VFF_FLUSH, VFF_FLUSH_B);
> +}
> +
> +static void mtk_dma_tx_write(struct dma_chan *chan)
> +{
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> + unsigned int txcount = c->remain_size;
> + unsigned int len, send, left, wpt, wrap;
> +
> + len = mtk_dma_chan_read(c, VFF_LEN);
> +
> + while ((left = mtk_dma_chan_read(c, VFF_LEFT_SIZE)) > 0U) {
> + if (c->remain_size == 0U)
> + break;
> + send = min(left, c->remain_size);
min_t
> + wpt = mtk_dma_chan_read(c, VFF_WPT);
> + wrap = wpt & MTK_DMA_RING_WRAP ? 0U : MTK_DMA_RING_WRAP;
> +
> + if ((wpt & (len - 1U)) + send < len)
> + mtk_dma_chan_write(c, VFF_WPT, wpt + send);
> + else
> + mtk_dma_chan_write(c, VFF_WPT,
> + ((wpt + send) & (len - 1U))
> + | wrap);
> +
> + c->remain_size -= send;
I'm curious why you don't need to set up the hardware from the
descriptor information
> + }
> +
> + if (txcount != c->remain_size) {
> + mtk_dma_chan_write(c, VFF_INT_EN, VFF_TX_INT_EN_B);
> + mtk_dma_tx_flush(chan);
> + }
> +}
> +
> +static void mtk_dma_start_tx(struct mtk_chan *c)
> +{
> + if (mtk_dma_chan_read(c, VFF_LEFT_SIZE) == 0U)
> + mtk_dma_chan_write(c, VFF_INT_EN, VFF_TX_INT_EN_B);
> + else
> + mtk_dma_tx_write(&c->vc.chan);
> +
> + c->stop = false;
> +}
> +
> +static void mtk_dma_get_rx_size(struct mtk_chan *c)
> +{
> + unsigned int rx_size = mtk_dma_chan_read(c, VFF_LEN);
> + unsigned int rdptr, wrptr, wrreg, rdreg, count;
> +
> + rdreg = mtk_dma_chan_read(c, VFF_RPT);
> + wrreg = mtk_dma_chan_read(c, VFF_WPT);
> + rdptr = rdreg & MTK_DMA_RING_SIZE;
> + wrptr = wrreg & MTK_DMA_RING_SIZE;
> + count = ((rdreg ^ wrreg) & MTK_DMA_RING_WRAP) ?
> + (wrptr + rx_size - rdptr) : (wrptr - rdptr);
> +
> + c->remain_size = count;
> + c->rx_ptr = rdptr;
> +
> + mtk_dma_chan_write(c, VFF_RPT, wrreg);
> +}
> +
> +static void mtk_dma_start_rx(struct mtk_chan *c)
> +{
> + struct dma_chan *chan = &c->vc.chan;
> + struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
> + struct mtk_dma_desc *d = c->desc;
> +
> + if (mtk_dma_chan_read(c, VFF_VALID_SIZE) == 0U)
> + return;
> +
> + if (d && d->vd.tx.cookie != 0) {
the driver benefits from virtual_channel so you can manage the life
cycle of each descriptor by the virtual channel related functions
without handling details about the cookie.
> + mtk_dma_get_rx_size(c);
> + mtk_dma_remove_virt_list(d->vd.tx.cookie, &c->vc);
> + vchan_cookie_complete(&d->vd);
> + } else {
> + spin_lock(&mtkd->lock);
> + if (list_empty(&mtkd->pending))
> + list_add_tail(&c->node, &mtkd->pending);
> + spin_unlock(&mtkd->lock);
> + tasklet_schedule(&mtkd->task);
> + }
> +}
> +
> +static void mtk_dma_reset(struct mtk_chan *c)
> +{
> + struct mtk_dmadev *mtkd = to_mtk_dma_dev(c->vc.chan.device);
> + u32 status;
> + int ret;
> +
> + mtk_dma_chan_write(c, VFF_ADDR, 0);
> + mtk_dma_chan_write(c, VFF_THRE, 0);
> + mtk_dma_chan_write(c, VFF_LEN, 0);
> + mtk_dma_chan_write(c, VFF_RST, VFF_WARM_RST_B);
> +
> + ret = readx_poll_timeout(readl,
> + c->base + VFF_EN,
> + status, status == 0, 10, 100);
> + if (ret) {
> + dev_err(c->vc.chan.device->dev,
> + "dma reset: fail, timeout\n");
> + return;
> + }
> +
> + if (c->cfg.direction == DMA_DEV_TO_MEM)
> + mtk_dma_chan_write(c, VFF_RPT, 0);
> + else if (c->cfg.direction == DMA_MEM_TO_DEV)
> + mtk_dma_chan_write(c, VFF_WPT, 0);
> +
> + if (mtkd->support_33bits)
> + mtk_dma_chan_write(c, VFF_4G_SUPPORT, VFF_4G_SUPPORT_CLR_B);
> +}
> +
> +static void mtk_dma_stop(struct mtk_chan *c)
> +{
> + u32 status;
> + int ret;
> +
> + mtk_dma_chan_write(c, VFF_FLUSH, VFF_FLUSH_CLR_B);
> + /* Wait for flush */
> + ret = readx_poll_timeout(readl,
> + c->base + VFF_FLUSH,
> + status,
> + (status & VFF_FLUSH_B) != VFF_FLUSH_B,
> + 10, 100);
> + if (ret)
> + dev_err(c->vc.chan.device->dev,
> + "dma stop: polling FLUSH fail, DEBUG=0x%x\n",
> + mtk_dma_chan_read(c, VFF_DEBUG_STATUS));
> +
> + /*set stop as 1 -> wait until en is 0 -> set stop as 0*/
> + mtk_dma_chan_write(c, VFF_STOP, VFF_STOP_B);
> + ret = readx_poll_timeout(readl,
> + c->base + VFF_EN,
> + status, status == 0, 10, 100);
> + if (ret)
> + dev_err(c->vc.chan.device->dev,
> + "dma stop: polling VFF_EN fail, DEBUG=0x%x\n",
> + mtk_dma_chan_read(c, VFF_DEBUG_STATUS));
> +
> + mtk_dma_chan_write(c, VFF_STOP, VFF_STOP_CLR_B);
> + mtk_dma_chan_write(c, VFF_INT_EN, VFF_INT_EN_CLR_B);
> +
> + if (c->cfg.direction == DMA_DEV_TO_MEM)
> + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_RX_INT_FLAG_CLR_B);
> + else
> + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_TX_INT_FLAG_CLR_B);
> +
> + c->stop = true;
> +}
> +
> +/*
> + * This callback schedules all pending channels. We could be more
> + * clever here by postponing allocation of the real DMA channels to
> + * this point, and freeing them when our virtual channel becomes idle.
> + *
> + * We would then need to deal with 'all channels in-use'
> + */
> +static void mtk_dma_sched(unsigned long data)
> +{
> + struct mtk_dmadev *mtkd = (struct mtk_dmadev *)data;
> + struct virt_dma_desc *vd;
> + struct mtk_chan *c;
> + dma_cookie_t cookie;
> + unsigned long flags;
> + LIST_HEAD(head);
> +
> + spin_lock_irq(&mtkd->lock);
> + list_splice_tail_init(&mtkd->pending, &head);
> + spin_unlock_irq(&mtkd->lock);
> +
> + if (!list_empty(&head)) {
> + c = list_first_entry(&head, struct mtk_chan, node);
> + cookie = c->vc.chan.cookie;
> +
> + spin_lock_irqsave(&c->vc.lock, flags);
> + if (c->cfg.direction == DMA_DEV_TO_MEM) {
> + list_del_init(&c->node);
> + mtk_dma_start_rx(c);
> + } else if (c->cfg.direction == DMA_MEM_TO_DEV) {
> + vd = vchan_find_desc(&c->vc, cookie);
> + c->desc = to_mtk_dma_desc(&vd->tx);
> + list_del_init(&c->node);
> + mtk_dma_start_tx(c);
> + }
> + spin_unlock_irqrestore(&c->vc.lock, flags);
> + }
> +}
> +
> +static int mtk_dma_alloc_chan_resources(struct dma_chan *chan)
> +{
> + struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> + int ret = -EBUSY;
> +
> + pm_runtime_get_sync(mtkd->ddev.dev);
> +
> + if (!mtkd->ch[c->dma_ch]) {
> + c->base = mtkd->mem_base[c->dma_ch];
> + mtkd->ch[c->dma_ch] = c;
> + ret = 1;
> + }
> + c->requested = false;
> + mtk_dma_reset(c);
> +
> + return ret;
> +}
> +
> +static void mtk_dma_free_chan_resources(struct dma_chan *chan)
> +{
> + struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> +
> + if (c->requested) {
> + c->requested = false;
> + free_irq(mtkd->dma_irq[c->dma_ch], chan);
> + }
> +
> + tasklet_kill(&mtkd->task);
> + tasklet_kill(&c->vc.task);
> +
> + c->base = NULL;
> + mtkd->ch[c->dma_ch] = NULL;
> + vchan_free_chan_resources(&c->vc);
> +
> + dev_dbg(mtkd->ddev.dev, "freeing channel for %u\n", c->dma_sig);
> + c->dma_sig = 0;
> +
> + pm_runtime_put_sync(mtkd->ddev.dev);
> +}
> +
> +static enum dma_status mtk_dma_tx_status(struct dma_chan *chan,
> + dma_cookie_t cookie,
> + struct dma_tx_state *txstate)
> +{
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> + enum dma_status ret;
> + unsigned long flags;
> +
> + if (!txstate)
> + return DMA_ERROR;
> +
> + ret = dma_cookie_status(chan, cookie, txstate);
> + spin_lock_irqsave(&c->vc.lock, flags);
> + if (ret == DMA_IN_PROGRESS) {
> + c->rx_ptr = mtk_dma_chan_read(c, VFF_RPT) & MTK_DMA_RING_SIZE;
> + dma_set_residue(txstate, c->rx_ptr);
> + } else if (ret == DMA_COMPLETE && c->cfg.direction == DMA_DEV_TO_MEM) {
> + dma_set_residue(txstate, c->remain_size);
> + } else {
> + dma_set_residue(txstate, 0);
> + }
> + spin_unlock_irqrestore(&c->vc.lock, flags);
> +
> + return ret;
> +}
> +
> +static struct dma_async_tx_descriptor *mtk_dma_prep_slave_sg
> + (struct dma_chan *chan, struct scatterlist *sgl,
> + unsigned int sglen, enum dma_transfer_direction dir,
> + unsigned long tx_flags, void *context)
> +{
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> + struct scatterlist *sgent;
> + struct mtk_dma_desc *d;
> + struct mtk_dma_sg *sg;
> + unsigned int size, i, j, en;
> +
> + en = 1;
> +
> + if ((dir != DMA_DEV_TO_MEM) &&
> + (dir != DMA_MEM_TO_DEV)) {
> + dev_err(chan->device->dev, "bad direction\n");
> + return NULL;
> + }
> +
> + /* Now allocate and setup the descriptor. */
> + d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC);
> + if (!d)
> + return NULL;
> +
> + d->dir = dir;
> +
> + j = 0;
> + for_each_sg(sgl, sgent, sglen, i) {
> + d->sg[j].addr = sg_dma_address(sgent);
> + d->sg[j].en = en;
> + d->sg[j].fn = sg_dma_len(sgent) / en;
> + j++;
> + }
> +
> + d->sglen = j;
> +
> + if (dir == DMA_MEM_TO_DEV) {
> + for (size = i = 0; i < d->sglen; i++) {
> + sg = &d->sg[i];
> + size += sg->en * sg->fn;
> + }
> + c->remain_size = size;
> + }
> +
> + return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
> +}
> +
> +static void mtk_dma_issue_pending(struct dma_chan *chan)
> +{
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> + struct virt_dma_desc *vd;
> + struct mtk_dmadev *mtkd;
> + dma_cookie_t cookie;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&c->vc.lock, flags);
> + if (c->cfg.direction == DMA_DEV_TO_MEM) {
> + cookie = c->vc.chan.cookie;
> + mtkd = to_mtk_dma_dev(chan->device);
> + if (vchan_issue_pending(&c->vc) && !c->desc) {
vchan_issue_pending means putting all the descriptors to list
desc_issued, I'm supposed somewhere would iterate the list by
vchan_next_desc and program each desc. into hardware. but I don't see
the similar code.
> + vd = vchan_find_desc(&c->vc, cookie);
> + c->desc = to_mtk_dma_desc(&vd->tx);
> + }
> + } else if (c->cfg.direction == DMA_MEM_TO_DEV) {
> + cookie = c->vc.chan.cookie;
> + if (vchan_issue_pending(&c->vc) && !c->desc) {
ditto as the above
> + vd = vchan_find_desc(&c->vc, cookie);
> + c->desc = to_mtk_dma_desc(&vd->tx);
> + mtk_dma_start_tx(c);
> + }
> + }
> + spin_unlock_irqrestore(&c->vc.lock, flags);
> +}
> +
> +static irqreturn_t mtk_dma_rx_interrupt(int irq, void *dev_id)
> +{
> + struct dma_chan *chan = (struct dma_chan *)dev_id;
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> + unsigned long flags;
> +
> + spin_lock_irqsave(&c->vc.lock, flags);
> + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_RX_INT_FLAG_CLR_B);
> +
> + mtk_dma_start_rx(c);
> +
> + spin_unlock_irqrestore(&c->vc.lock, flags);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t mtk_dma_tx_interrupt(int irq, void *dev_id)
> +{
> + struct dma_chan *chan = (struct dma_chan *)dev_id;
> + struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> + struct mtk_dma_desc *d = c->desc;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&c->vc.lock, flags);
> + if (c->remain_size != 0U) {
> + list_add_tail(&c->node, &mtkd->pending);
> + tasklet_schedule(&mtkd->task);
> + } else {
> + mtk_dma_remove_virt_list(d->vd.tx.cookie, &c->vc);
> + vchan_cookie_complete(&d->vd);
> + }
> + spin_unlock_irqrestore(&c->vc.lock, flags);
> +
> + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_TX_INT_FLAG_CLR_B);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int mtk_dma_slave_config(struct dma_chan *chan,
> + struct dma_slave_config *cfg)
> +{
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> + struct mtk_dmadev *mtkd = to_mtk_dma_dev(c->vc.chan.device);
> + int ret;
> +
> + c->cfg = *cfg;
> +
> + if (cfg->direction == DMA_DEV_TO_MEM) {
> + unsigned int rx_len = cfg->src_addr_width * 1024;
> +
> + mtk_dma_chan_write(c, VFF_ADDR, cfg->src_addr);
> + mtk_dma_chan_write(c, VFF_LEN, rx_len);
> + mtk_dma_chan_write(c, VFF_THRE, VFF_RX_THRE(rx_len));
> + mtk_dma_chan_write(c,
> + VFF_INT_EN, VFF_RX_INT_EN0_B
> + | VFF_RX_INT_EN1_B);
> + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_RX_INT_FLAG_CLR_B);
> + mtk_dma_chan_write(c, VFF_EN, VFF_EN_B);
> +
> + if (!c->requested) {
> + c->requested = true;
> + ret = request_irq(mtkd->dma_irq[c->dma_ch],
> + mtk_dma_rx_interrupt,
> + IRQF_TRIGGER_NONE,
> + KBUILD_MODNAME, chan);
> + if (ret < 0) {
> + dev_err(chan->device->dev, "Can't request rx dma IRQ\n");
> + return -EINVAL;
> + }
> + }
> + } else if (cfg->direction == DMA_MEM_TO_DEV) {
> + unsigned int tx_len = cfg->dst_addr_width * 1024;
> +
> + mtk_dma_chan_write(c, VFF_ADDR, cfg->dst_addr);
> + mtk_dma_chan_write(c, VFF_LEN, tx_len);
> + mtk_dma_chan_write(c, VFF_THRE, VFF_TX_THRE(tx_len));
> + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_TX_INT_FLAG_CLR_B);
> + mtk_dma_chan_write(c, VFF_EN, VFF_EN_B);
> +
> + if (!c->requested) {
> + c->requested = true;
> + ret = request_irq(mtkd->dma_irq[c->dma_ch],
> + mtk_dma_tx_interrupt,
> + IRQF_TRIGGER_NONE,
> + KBUILD_MODNAME, chan);
> + if (ret < 0) {
> + dev_err(chan->device->dev, "Can't request tx dma IRQ\n");
> + return -EINVAL;
> + }
> + }
> + }
> +
> + if (mtkd->support_33bits)
> + mtk_dma_chan_write(c, VFF_4G_SUPPORT, VFF_4G_SUPPORT_B);
> +
> + if (mtk_dma_chan_read(c, VFF_EN) != VFF_EN_B) {
> + dev_err(chan->device->dev,
> + "config dma dir[%d] fail\n", cfg->direction);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int mtk_dma_terminate_all(struct dma_chan *chan)
> +{
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> + unsigned long flags;
> +
> + spin_lock_irqsave(&c->vc.lock, flags);
> + list_del_init(&c->node);
> + mtk_dma_stop(c);
> + spin_unlock_irqrestore(&c->vc.lock, flags);
> +
> + return 0;
> +}
> +
> +static int mtk_dma_device_pause(struct dma_chan *chan)
> +{
> + /* just for check caps pass */
> + return -EINVAL;
> +}
it it possible not to register the function to the core if the
hardware doesn't support it?
> +
> +static int mtk_dma_device_resume(struct dma_chan *chan)
> +{
> + /* just for check caps pass */
> + return -EINVAL;
> +}
ditto as the above
> +
> +static void mtk_dma_free(struct mtk_dmadev *mtkd)
> +{
> + tasklet_kill(&mtkd->task);
> + while (list_empty(&mtkd->ddev.channels) == 0) {
> + struct mtk_chan *c = list_first_entry(&mtkd->ddev.channels,
> + struct mtk_chan, vc.chan.device_node);
> +
> + list_del(&c->vc.chan.device_node);
> + tasklet_kill(&c->vc.task);
> + devm_kfree(mtkd->ddev.dev, c);
> + }
> +}
> +
> +static const struct of_device_id mtk_uart_dma_match[] = {
> + { .compatible = "mediatek,mt6577-uart-dma", },
> + { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, mtk_uart_dma_match);
> +
> +static int mtk_apdma_probe(struct platform_device *pdev)
> +{
> + struct mtk_dmadev *mtkd;
> + struct resource *res;
> + struct mtk_chan *c;
> + unsigned int i;
> + int rc;
> +
> + mtkd = devm_kzalloc(&pdev->dev, sizeof(*mtkd), GFP_KERNEL);
> + if (!mtkd)
> + return -ENOMEM;
> +
> + for (i = 0; i < MTK_APDMA_CHANNELS; i++) {
> + res = platform_get_resource(pdev, IORESOURCE_MEM, i);
> + if (!res)
> + return -ENODEV;
> + mtkd->mem_base[i] = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(mtkd->mem_base[i]))
> + return PTR_ERR(mtkd->mem_base[i]);
> + }
> +
> + for (i = 0; i < MTK_APDMA_CHANNELS; i++) {
> + mtkd->dma_irq[i] = platform_get_irq(pdev, i);
> + if ((int)mtkd->dma_irq[i] < 0) {
> + dev_err(&pdev->dev, "failed to get IRQ[%d]\n", i);
> + return -EINVAL;
> + }
> + }
> +
> + mtkd->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(mtkd->clk)) {
> + dev_err(&pdev->dev, "No clock specified\n");
> + return PTR_ERR(mtkd->clk);
> + }
> +
> + if (of_property_read_bool(pdev->dev.of_node, "dma-33bits")) {
> + dev_info(&pdev->dev, "Support dma 33bits\n");
> + mtkd->support_33bits = true;
> + }
> +
> + if (mtkd->support_33bits)
> + rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(33));
> + else
> + rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> + if (rc)
> + return rc;
> +
> + dma_cap_set(DMA_SLAVE, mtkd->ddev.cap_mask);
> + mtkd->ddev.device_alloc_chan_resources = mtk_dma_alloc_chan_resources;
> + mtkd->ddev.device_free_chan_resources = mtk_dma_free_chan_resources;
> + mtkd->ddev.device_tx_status = mtk_dma_tx_status;
> + mtkd->ddev.device_issue_pending = mtk_dma_issue_pending;
> + mtkd->ddev.device_prep_slave_sg = mtk_dma_prep_slave_sg;
> + mtkd->ddev.device_config = mtk_dma_slave_config;
> + mtkd->ddev.device_pause = mtk_dma_device_pause;
> + mtkd->ddev.device_resume = mtk_dma_device_resume;
> + mtkd->ddev.device_terminate_all = mtk_dma_terminate_all;
> + mtkd->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE);
> + mtkd->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE);
> + mtkd->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
> + mtkd->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
> + mtkd->ddev.dev = &pdev->dev;
> + INIT_LIST_HEAD(&mtkd->ddev.channels);
> + INIT_LIST_HEAD(&mtkd->pending);
> +
> + spin_lock_init(&mtkd->lock);
> + tasklet_init(&mtkd->task, mtk_dma_sched, (unsigned long)mtkd);
> +
> + mtkd->dma_requests = MTK_APDMA_DEFAULT_REQUESTS;
> + if (of_property_read_u32(pdev->dev.of_node,
> + "dma-requests", &mtkd->dma_requests)) {
> + dev_info(&pdev->dev,
> + "Missing dma-requests property, using %u.\n",
> + MTK_APDMA_DEFAULT_REQUESTS);
> + }
> +
> + for (i = 0; i < MTK_APDMA_CHANNELS; i++) {
> + c = devm_kzalloc(mtkd->ddev.dev, sizeof(*c), GFP_KERNEL);
> + if (!c)
> + goto err_no_dma;
> +
> + c->vc.desc_free = mtk_dma_desc_free;
> + vchan_init(&c->vc, &mtkd->ddev);
> + INIT_LIST_HEAD(&c->node);
> + }
> +
> + pm_runtime_enable(&pdev->dev);
> + pm_runtime_set_active(&pdev->dev);
> +
> + rc = dma_async_device_register(&mtkd->ddev);
> + if (rc)
> + goto rpm_disable;
> +
> + platform_set_drvdata(pdev, mtkd);
> +
> + if (pdev->dev.of_node) {
> + mtk_dma_info.dma_cap = mtkd->ddev.cap_mask;
> +
> + /* Device-tree DMA controller registration */
> + rc = of_dma_controller_register(pdev->dev.of_node,
> + of_dma_simple_xlate,
> + &mtk_dma_info);
reusing of_dma_xlate_by_chan_id seem that also work for you.
> + if (rc)
> + goto dma_remove;
> + }
> +
> + return rc;
> +
> +dma_remove:
> + dma_async_device_unregister(&mtkd->ddev);
> +rpm_disable:
> + pm_runtime_disable(&pdev->dev);
> +err_no_dma:
> + mtk_dma_free(mtkd);
> + return rc;
> +}
> +
> +static int mtk_apdma_remove(struct platform_device *pdev)
> +{
> + struct mtk_dmadev *mtkd = platform_get_drvdata(pdev);
> +
> + if (pdev->dev.of_node)
> + of_dma_controller_free(pdev->dev.of_node);
> +
> + pm_runtime_disable(&pdev->dev);
> + pm_runtime_put_noidle(&pdev->dev);
> +
> + dma_async_device_unregister(&mtkd->ddev);
> +
> + mtk_dma_free(mtkd);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int mtk_dma_suspend(struct device *dev)
> +{
> + struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
> +
> + if (!pm_runtime_suspended(dev))
> + mtk_dma_clk_disable(mtkd);
> +
> + return 0;
> +}
> +
> +static int mtk_dma_resume(struct device *dev)
> +{
> + int ret;
> + struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
> +
> + if (!pm_runtime_suspended(dev)) {
> + ret = mtk_dma_clk_enable(mtkd);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int mtk_dma_runtime_suspend(struct device *dev)
> +{
> + struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
> +
> + mtk_dma_clk_disable(mtkd);
> +
> + return 0;
> +}
> +
> +static int mtk_dma_runtime_resume(struct device *dev)
> +{
> + int ret;
> + struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
> +
> + ret = mtk_dma_clk_enable(mtkd);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +#endif /* CONFIG_PM_SLEEP */
> +
> +static const struct dev_pm_ops mtk_dma_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(mtk_dma_suspend, mtk_dma_resume)
> + SET_RUNTIME_PM_OPS(mtk_dma_runtime_suspend,
> + mtk_dma_runtime_resume, NULL)
> +};
> +
> +static struct platform_driver mtk_dma_driver = {
> + .probe = mtk_apdma_probe,
> + .remove = mtk_apdma_remove,
> + .driver = {
> + .name = KBUILD_MODNAME,
> + .pm = &mtk_dma_pm_ops,
> + .of_match_table = of_match_ptr(mtk_uart_dma_match),
> + },
> +};
> +
> +static bool mtk_dma_filter_fn(struct dma_chan *chan, void *param)
> +{
> + if (chan->device->dev->driver == &mtk_dma_driver.driver) {
> + struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
> + struct mtk_chan *c = to_mtk_dma_chan(chan);
> + unsigned int req = *(unsigned int *)param;
> +
> + if (req <= mtkd->dma_requests) {
> + c->dma_sig = req;
> + c->dma_ch = req;
> + return true;
> + }
> + }
> + return false;
> +}
> +
> +module_platform_driver(mtk_dma_driver);
> +
> +MODULE_DESCRIPTION("MediaTek UART APDMA Controller Driver");
> +MODULE_AUTHOR("Long Cheng <[email protected]>");
> +MODULE_LICENSE("GPL v2");
> +
> diff --git a/drivers/dma/mediatek/Kconfig b/drivers/dma/mediatek/Kconfig
> index 27bac0b..bef436e 100644
> --- a/drivers/dma/mediatek/Kconfig
> +++ b/drivers/dma/mediatek/Kconfig
> @@ -1,4 +1,15 @@
>
> +config DMA_MTK_UART
> + tristate "MediaTek SoCs APDMA support for UART"
> + depends on OF
> + select DMA_ENGINE
> + select DMA_VIRTUAL_CHANNELS
> + help
> + Support for the UART DMA engine found on MediaTek MTK SoCs.
> + when 8250 mtk uart is enabled, and if you want to using DMA,
> + you can enable the config. the DMA engine just only be used
> + with MediaTek Socs.
> +
> config MTK_HSDMA
> tristate "MediaTek High-Speed DMA controller support"
> depends on ARCH_MEDIATEK || COMPILE_TEST
> diff --git a/drivers/dma/mediatek/Makefile b/drivers/dma/mediatek/Makefile
> index 6e778f8..2f2efd9 100644
> --- a/drivers/dma/mediatek/Makefile
> +++ b/drivers/dma/mediatek/Makefile
> @@ -1 +1,2 @@
> +obj-$(CONFIG_DMA_MTK_UART) += 8250_mtk_dma.o
> obj-$(CONFIG_MTK_HSDMA) += mtk-hsdma.o
> --
> 1.7.9.5
>
>
> _______________________________________________
> Linux-mediatek mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-mediatek
On Wed, 2018-12-05 at 13:07 -0800, Sean Wang wrote:
> .
> On Wed, Dec 5, 2018 at 1:31 AM Long Cheng <[email protected]> wrote:
> >
> > In DMA engine framework, add 8250 mtk dma to support it.
> >
> > Signed-off-by: Long Cheng <[email protected]>
> > ---
> > drivers/dma/mediatek/8250_mtk_dma.c | 894 +++++++++++++++++++++++++++++++++++
> > drivers/dma/mediatek/Kconfig | 11 +
> > drivers/dma/mediatek/Makefile | 1 +
> > 3 files changed, 906 insertions(+)
> > create mode 100644 drivers/dma/mediatek/8250_mtk_dma.c
> >
> > diff --git a/drivers/dma/mediatek/8250_mtk_dma.c b/drivers/dma/mediatek/8250_mtk_dma.c
> > new file mode 100644
> > index 0000000..3454679
> > --- /dev/null
> > +++ b/drivers/dma/mediatek/8250_mtk_dma.c
> > @@ -0,0 +1,894 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Mediatek 8250 DMA driver.
> > + *
> > + * Copyright (c) 2018 MediaTek Inc.
> > + * Author: Long Cheng <[email protected]>
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/dmaengine.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/err.h>
> > +#include <linux/init.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/list.h>
> > +#include <linux/module.h>
> > +#include <linux/of_dma.h>
> > +#include <linux/of_device.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/iopoll.h>
> > +
> > +#include "../virt-dma.h"
> > +
> > +#define MTK_APDMA_DEFAULT_REQUESTS 127
> > +#define MTK_APDMA_CHANNELS (CONFIG_SERIAL_8250_NR_UARTS * 2)
> > +
> > +#define VFF_EN_B BIT(0)
> > +#define VFF_STOP_B BIT(0)
> > +#define VFF_FLUSH_B BIT(0)
> > +#define VFF_4G_SUPPORT_B BIT(0)
> > +#define VFF_RX_INT_EN0_B BIT(0) /*rx valid size >= vff thre*/
> > +#define VFF_RX_INT_EN1_B BIT(1)
> > +#define VFF_TX_INT_EN_B BIT(0) /*tx left size >= vff thre*/
> > +#define VFF_WARM_RST_B BIT(0)
> > +#define VFF_RX_INT_FLAG_CLR_B (BIT(0) | BIT(1))
> > +#define VFF_TX_INT_FLAG_CLR_B 0
> > +#define VFF_STOP_CLR_B 0
> > +#define VFF_FLUSH_CLR_B 0
> > +#define VFF_INT_EN_CLR_B 0
> > +#define VFF_4G_SUPPORT_CLR_B 0
> > +
> > +/* interrupt trigger level for tx */
> > +#define VFF_TX_THRE(n) ((n) * 7 / 8)
> > +/* interrupt trigger level for rx */
> > +#define VFF_RX_THRE(n) ((n) * 3 / 4)
> > +
> > +#define MTK_DMA_RING_SIZE 0xffffU
> > +/* invert this bit when wrap ring head again*/
> > +#define MTK_DMA_RING_WRAP 0x10000U
> > +
> > +#define VFF_INT_FLAG 0x00
> > +#define VFF_INT_EN 0x04
> > +#define VFF_EN 0x08
> > +#define VFF_RST 0x0c
> > +#define VFF_STOP 0x10
> > +#define VFF_FLUSH 0x14
> > +#define VFF_ADDR 0x1c
> > +#define VFF_LEN 0x24
> > +#define VFF_THRE 0x28
> > +#define VFF_WPT 0x2c
> > +#define VFF_RPT 0x30
> > +/*TX: the buffer size HW can read. RX: the buffer size SW can read.*/
> > +#define VFF_VALID_SIZE 0x3c
> > +/*TX: the buffer size SW can write. RX: the buffer size HW can write.*/
> > +#define VFF_LEFT_SIZE 0x40
> > +#define VFF_DEBUG_STATUS 0x50
> > +#define VFF_4G_SUPPORT 0x54
> > +
> > +struct mtk_dmadev {
> > + struct dma_device ddev;
> > + void __iomem *mem_base[MTK_APDMA_CHANNELS];
> > + spinlock_t lock; /* dma dev lock */
> > + struct tasklet_struct task;
> > + struct list_head pending;
> > + struct clk *clk;
> > + unsigned int dma_requests;
> > + bool support_33bits;
> > + unsigned int dma_irq[MTK_APDMA_CHANNELS];
> > + struct mtk_chan *ch[MTK_APDMA_CHANNELS];
> > +};
> > +
> > +struct mtk_chan {
> > + struct virt_dma_chan vc;
> > + struct list_head node;
> > + struct dma_slave_config cfg;
> > + void __iomem *base;
> > + struct mtk_dma_desc *desc;
> > +
> > + bool stop;
> > + bool requested;
> > +
> > + unsigned int dma_sig;
>
> the member can be removed as no real user would refer to it
>
Ok, i will remove it at next patch
> > + unsigned int dma_ch;
>
> a chan_id is already included in struct dma_chan, we can reuse it
>
chan_id is start from 0. but in this driver, dma info is stored to list.
if use port1, in filter_fn function, will set dma_ch to 2, 3(tx, rx). So
can't using chan_id
> > + unsigned int sgidx;
>
> the member also can be removed as no real user would refer to it
>
Ok, i will remove it at next patch
> > + unsigned int remain_size;
>
> The member remain_size seems unnecessary data to maintain a channel.
> The virtual channel struct virt_dma_chan already provide the way to
> manage all descriptors you're operating on, you should reuse related
> functions to virt_dma_chan first.
>
> Or if you mean remain_size is about the remaining size of current
> descriptor, and then putting into struct mtk_dma_desc would be better.
>
i will move it to mtk_dma_desc
> > + unsigned int rx_ptr;
> > +};
> > +
> > +struct mtk_dma_sg {
> > + dma_addr_t addr;
> > + unsigned int en; /* number of elements (24-bit) */
> > + unsigned int fn; /* number of frames (16-bit) */
> > +};
> > +
> > +struct mtk_dma_desc {
> > + struct virt_dma_desc vd;
> > + enum dma_transfer_direction dir;
> > +
> > + unsigned int sglen;
> > + struct mtk_dma_sg sg[0];
> > +};
> > +
> > +static bool mtk_dma_filter_fn(struct dma_chan *chan, void *param);
> > +static struct of_dma_filter_info mtk_dma_info = {
> > + .filter_fn = mtk_dma_filter_fn,
> > +};
> > +
> > +static inline struct mtk_dmadev *to_mtk_dma_dev(struct dma_device *d)
> > +{
> > + return container_of(d, struct mtk_dmadev, ddev);
> > +}
> > +
> > +static inline struct mtk_chan *to_mtk_dma_chan(struct dma_chan *c)
> > +{
> > + return container_of(c, struct mtk_chan, vc.chan);
> > +}
> > +
> > +static inline struct mtk_dma_desc *to_mtk_dma_desc
> > + (struct dma_async_tx_descriptor *t)
> > +{
> > + return container_of(t, struct mtk_dma_desc, vd.tx);
> > +}
> > +
> > +static void mtk_dma_chan_write(struct mtk_chan *c,
> > + unsigned int reg, unsigned int val)
> > +{
> > + writel(val, c->base + reg);
> > +}
> > +
> > +static unsigned int mtk_dma_chan_read(struct mtk_chan *c, unsigned int reg)
> > +{
> > + return readl(c->base + reg);
> > +}
> > +
> > +static void mtk_dma_desc_free(struct virt_dma_desc *vd)
> > +{
> > + struct dma_chan *chan = vd->tx.chan;
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > +
> > + kfree(c->desc);
> > + c->desc = NULL;
> > +}
> > +
> > +static int mtk_dma_clk_enable(struct mtk_dmadev *mtkd)
> > +{
> > + int ret;
> > +
> > + ret = clk_prepare_enable(mtkd->clk);
> > + if (ret) {
> > + dev_err(mtkd->ddev.dev, "Couldn't enable the clock\n");
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static void mtk_dma_clk_disable(struct mtk_dmadev *mtkd)
> > +{
> > + clk_disable_unprepare(mtkd->clk);
> > +}
> > +
> > +static void mtk_dma_remove_virt_list(dma_cookie_t cookie,
> > + struct virt_dma_chan *vc)
> > +{
> > + struct virt_dma_desc *vd;
> > +
> > + if (list_empty(&vc->desc_issued) == 0) {
> > + list_for_each_entry(vd, &vc->desc_issued, node) {
> > + if (cookie == vd->tx.cookie) {
> > + INIT_LIST_HEAD(&vc->desc_issued);
>
> generally, we don't force initialze the list desc_issued. Instead,
> when each descriptor is completed, we need to move each descriptor
> from the list desc_issued to the list desc_completed.
>
ok, i will modify it at next patch
> > + break;
> > + }
> > + }
> > + }
> > +}
> > +
> > +static void mtk_dma_tx_flush(struct dma_chan *chan)
> > +{
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > +
> > + if (mtk_dma_chan_read(c, VFF_FLUSH) == 0U)
> > + mtk_dma_chan_write(c, VFF_FLUSH, VFF_FLUSH_B);
> > +}
> > +
> > +static void mtk_dma_tx_write(struct dma_chan *chan)
> > +{
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > + unsigned int txcount = c->remain_size;
> > + unsigned int len, send, left, wpt, wrap;
> > +
> > + len = mtk_dma_chan_read(c, VFF_LEN);
> > +
> > + while ((left = mtk_dma_chan_read(c, VFF_LEFT_SIZE)) > 0U) {
> > + if (c->remain_size == 0U)
> > + break;
> > + send = min(left, c->remain_size);
>
> min_t
>
ok, i will modify it at next patch
> > + wpt = mtk_dma_chan_read(c, VFF_WPT);
> > + wrap = wpt & MTK_DMA_RING_WRAP ? 0U : MTK_DMA_RING_WRAP;
> > +
> > + if ((wpt & (len - 1U)) + send < len)
> > + mtk_dma_chan_write(c, VFF_WPT, wpt + send);
> > + else
> > + mtk_dma_chan_write(c, VFF_WPT,
> > + ((wpt + send) & (len - 1U))
> > + | wrap);
> > +
> > + c->remain_size -= send;
>
> I'm curious why you don't need to set up the hardware from the
> descriptor information
>
mtk_dma_chan_write is update the hardware. remain_size is length of TX
data.
> > + }
> > +
> > + if (txcount != c->remain_size) {
> > + mtk_dma_chan_write(c, VFF_INT_EN, VFF_TX_INT_EN_B);
> > + mtk_dma_tx_flush(chan);
> > + }
> > +}
> > +
> > +static void mtk_dma_start_tx(struct mtk_chan *c)
> > +{
> > + if (mtk_dma_chan_read(c, VFF_LEFT_SIZE) == 0U)
> > + mtk_dma_chan_write(c, VFF_INT_EN, VFF_TX_INT_EN_B);
> > + else
> > + mtk_dma_tx_write(&c->vc.chan);
> > +
> > + c->stop = false;
> > +}
> > +
> > +static void mtk_dma_get_rx_size(struct mtk_chan *c)
> > +{
> > + unsigned int rx_size = mtk_dma_chan_read(c, VFF_LEN);
> > + unsigned int rdptr, wrptr, wrreg, rdreg, count;
> > +
> > + rdreg = mtk_dma_chan_read(c, VFF_RPT);
> > + wrreg = mtk_dma_chan_read(c, VFF_WPT);
> > + rdptr = rdreg & MTK_DMA_RING_SIZE;
> > + wrptr = wrreg & MTK_DMA_RING_SIZE;
> > + count = ((rdreg ^ wrreg) & MTK_DMA_RING_WRAP) ?
> > + (wrptr + rx_size - rdptr) : (wrptr - rdptr);
> > +
> > + c->remain_size = count;
> > + c->rx_ptr = rdptr;
> > +
> > + mtk_dma_chan_write(c, VFF_RPT, wrreg);
> > +}
> > +
> > +static void mtk_dma_start_rx(struct mtk_chan *c)
> > +{
> > + struct dma_chan *chan = &c->vc.chan;
> > + struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
> > + struct mtk_dma_desc *d = c->desc;
> > +
> > + if (mtk_dma_chan_read(c, VFF_VALID_SIZE) == 0U)
> > + return;
> > +
> > + if (d && d->vd.tx.cookie != 0) {
>
> the driver benefits from virtual_channel so you can manage the life
> cycle of each descriptor by the virtual channel related functions
> without handling details about the cookie.
>
ok, i will modify it at next patch
> > + mtk_dma_get_rx_size(c);
> > + mtk_dma_remove_virt_list(d->vd.tx.cookie, &c->vc);
> > + vchan_cookie_complete(&d->vd);
> > + } else {
> > + spin_lock(&mtkd->lock);
> > + if (list_empty(&mtkd->pending))
> > + list_add_tail(&c->node, &mtkd->pending);
> > + spin_unlock(&mtkd->lock);
> > + tasklet_schedule(&mtkd->task);
> > + }
> > +}
> > +
> > +static void mtk_dma_reset(struct mtk_chan *c)
> > +{
> > + struct mtk_dmadev *mtkd = to_mtk_dma_dev(c->vc.chan.device);
> > + u32 status;
> > + int ret;
> > +
> > + mtk_dma_chan_write(c, VFF_ADDR, 0);
> > + mtk_dma_chan_write(c, VFF_THRE, 0);
> > + mtk_dma_chan_write(c, VFF_LEN, 0);
> > + mtk_dma_chan_write(c, VFF_RST, VFF_WARM_RST_B);
> > +
> > + ret = readx_poll_timeout(readl,
> > + c->base + VFF_EN,
> > + status, status == 0, 10, 100);
> > + if (ret) {
> > + dev_err(c->vc.chan.device->dev,
> > + "dma reset: fail, timeout\n");
> > + return;
> > + }
> > +
> > + if (c->cfg.direction == DMA_DEV_TO_MEM)
> > + mtk_dma_chan_write(c, VFF_RPT, 0);
> > + else if (c->cfg.direction == DMA_MEM_TO_DEV)
> > + mtk_dma_chan_write(c, VFF_WPT, 0);
> > +
> > + if (mtkd->support_33bits)
> > + mtk_dma_chan_write(c, VFF_4G_SUPPORT, VFF_4G_SUPPORT_CLR_B);
> > +}
> > +
> > +static void mtk_dma_stop(struct mtk_chan *c)
> > +{
> > + u32 status;
> > + int ret;
> > +
> > + mtk_dma_chan_write(c, VFF_FLUSH, VFF_FLUSH_CLR_B);
> > + /* Wait for flush */
> > + ret = readx_poll_timeout(readl,
> > + c->base + VFF_FLUSH,
> > + status,
> > + (status & VFF_FLUSH_B) != VFF_FLUSH_B,
> > + 10, 100);
> > + if (ret)
> > + dev_err(c->vc.chan.device->dev,
> > + "dma stop: polling FLUSH fail, DEBUG=0x%x\n",
> > + mtk_dma_chan_read(c, VFF_DEBUG_STATUS));
> > +
> > + /*set stop as 1 -> wait until en is 0 -> set stop as 0*/
> > + mtk_dma_chan_write(c, VFF_STOP, VFF_STOP_B);
> > + ret = readx_poll_timeout(readl,
> > + c->base + VFF_EN,
> > + status, status == 0, 10, 100);
> > + if (ret)
> > + dev_err(c->vc.chan.device->dev,
> > + "dma stop: polling VFF_EN fail, DEBUG=0x%x\n",
> > + mtk_dma_chan_read(c, VFF_DEBUG_STATUS));
> > +
> > + mtk_dma_chan_write(c, VFF_STOP, VFF_STOP_CLR_B);
> > + mtk_dma_chan_write(c, VFF_INT_EN, VFF_INT_EN_CLR_B);
> > +
> > + if (c->cfg.direction == DMA_DEV_TO_MEM)
> > + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_RX_INT_FLAG_CLR_B);
> > + else
> > + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_TX_INT_FLAG_CLR_B);
> > +
> > + c->stop = true;
> > +}
> > +
> > +/*
> > + * This callback schedules all pending channels. We could be more
> > + * clever here by postponing allocation of the real DMA channels to
> > + * this point, and freeing them when our virtual channel becomes idle.
> > + *
> > + * We would then need to deal with 'all channels in-use'
> > + */
> > +static void mtk_dma_sched(unsigned long data)
> > +{
> > + struct mtk_dmadev *mtkd = (struct mtk_dmadev *)data;
> > + struct virt_dma_desc *vd;
> > + struct mtk_chan *c;
> > + dma_cookie_t cookie;
> > + unsigned long flags;
> > + LIST_HEAD(head);
> > +
> > + spin_lock_irq(&mtkd->lock);
> > + list_splice_tail_init(&mtkd->pending, &head);
> > + spin_unlock_irq(&mtkd->lock);
> > +
> > + if (!list_empty(&head)) {
> > + c = list_first_entry(&head, struct mtk_chan, node);
> > + cookie = c->vc.chan.cookie;
> > +
> > + spin_lock_irqsave(&c->vc.lock, flags);
> > + if (c->cfg.direction == DMA_DEV_TO_MEM) {
> > + list_del_init(&c->node);
> > + mtk_dma_start_rx(c);
> > + } else if (c->cfg.direction == DMA_MEM_TO_DEV) {
> > + vd = vchan_find_desc(&c->vc, cookie);
> > + c->desc = to_mtk_dma_desc(&vd->tx);
> > + list_del_init(&c->node);
> > + mtk_dma_start_tx(c);
> > + }
> > + spin_unlock_irqrestore(&c->vc.lock, flags);
> > + }
> > +}
> > +
> > +static int mtk_dma_alloc_chan_resources(struct dma_chan *chan)
> > +{
> > + struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > + int ret = -EBUSY;
> > +
> > + pm_runtime_get_sync(mtkd->ddev.dev);
> > +
> > + if (!mtkd->ch[c->dma_ch]) {
> > + c->base = mtkd->mem_base[c->dma_ch];
> > + mtkd->ch[c->dma_ch] = c;
> > + ret = 1;
> > + }
> > + c->requested = false;
> > + mtk_dma_reset(c);
> > +
> > + return ret;
> > +}
> > +
> > +static void mtk_dma_free_chan_resources(struct dma_chan *chan)
> > +{
> > + struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > +
> > + if (c->requested) {
> > + c->requested = false;
> > + free_irq(mtkd->dma_irq[c->dma_ch], chan);
> > + }
> > +
> > + tasklet_kill(&mtkd->task);
> > + tasklet_kill(&c->vc.task);
> > +
> > + c->base = NULL;
> > + mtkd->ch[c->dma_ch] = NULL;
> > + vchan_free_chan_resources(&c->vc);
> > +
> > + dev_dbg(mtkd->ddev.dev, "freeing channel for %u\n", c->dma_sig);
> > + c->dma_sig = 0;
> > +
> > + pm_runtime_put_sync(mtkd->ddev.dev);
> > +}
> > +
> > +static enum dma_status mtk_dma_tx_status(struct dma_chan *chan,
> > + dma_cookie_t cookie,
> > + struct dma_tx_state *txstate)
> > +{
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > + enum dma_status ret;
> > + unsigned long flags;
> > +
> > + if (!txstate)
> > + return DMA_ERROR;
> > +
> > + ret = dma_cookie_status(chan, cookie, txstate);
> > + spin_lock_irqsave(&c->vc.lock, flags);
> > + if (ret == DMA_IN_PROGRESS) {
> > + c->rx_ptr = mtk_dma_chan_read(c, VFF_RPT) & MTK_DMA_RING_SIZE;
> > + dma_set_residue(txstate, c->rx_ptr);
> > + } else if (ret == DMA_COMPLETE && c->cfg.direction == DMA_DEV_TO_MEM) {
> > + dma_set_residue(txstate, c->remain_size);
> > + } else {
> > + dma_set_residue(txstate, 0);
> > + }
> > + spin_unlock_irqrestore(&c->vc.lock, flags);
> > +
> > + return ret;
> > +}
> > +
> > +static struct dma_async_tx_descriptor *mtk_dma_prep_slave_sg
> > + (struct dma_chan *chan, struct scatterlist *sgl,
> > + unsigned int sglen, enum dma_transfer_direction dir,
> > + unsigned long tx_flags, void *context)
> > +{
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > + struct scatterlist *sgent;
> > + struct mtk_dma_desc *d;
> > + struct mtk_dma_sg *sg;
> > + unsigned int size, i, j, en;
> > +
> > + en = 1;
> > +
> > + if ((dir != DMA_DEV_TO_MEM) &&
> > + (dir != DMA_MEM_TO_DEV)) {
> > + dev_err(chan->device->dev, "bad direction\n");
> > + return NULL;
> > + }
> > +
> > + /* Now allocate and setup the descriptor. */
> > + d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC);
> > + if (!d)
> > + return NULL;
> > +
> > + d->dir = dir;
> > +
> > + j = 0;
> > + for_each_sg(sgl, sgent, sglen, i) {
> > + d->sg[j].addr = sg_dma_address(sgent);
> > + d->sg[j].en = en;
> > + d->sg[j].fn = sg_dma_len(sgent) / en;
> > + j++;
> > + }
> > +
> > + d->sglen = j;
> > +
> > + if (dir == DMA_MEM_TO_DEV) {
> > + for (size = i = 0; i < d->sglen; i++) {
> > + sg = &d->sg[i];
> > + size += sg->en * sg->fn;
> > + }
> > + c->remain_size = size;
> > + }
> > +
> > + return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
> > +}
> > +
> > +static void mtk_dma_issue_pending(struct dma_chan *chan)
> > +{
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > + struct virt_dma_desc *vd;
> > + struct mtk_dmadev *mtkd;
> > + dma_cookie_t cookie;
> > + unsigned long flags;
> > +
> > + spin_lock_irqsave(&c->vc.lock, flags);
> > + if (c->cfg.direction == DMA_DEV_TO_MEM) {
> > + cookie = c->vc.chan.cookie;
> > + mtkd = to_mtk_dma_dev(chan->device);
> > + if (vchan_issue_pending(&c->vc) && !c->desc) {
>
> vchan_issue_pending means putting all the descriptors to list
> desc_issued, I'm supposed somewhere would iterate the list by
> vchan_next_desc and program each desc. into hardware. but I don't see
> the similar code.
ok, i will modify it at next patch
>
> > + vd = vchan_find_desc(&c->vc, cookie);
> > + c->desc = to_mtk_dma_desc(&vd->tx);
> > + }
> > + } else if (c->cfg.direction == DMA_MEM_TO_DEV) {
> > + cookie = c->vc.chan.cookie;
> > + if (vchan_issue_pending(&c->vc) && !c->desc) {
>
> ditto as the above
>
ok, i will modify it at next patch
> > + vd = vchan_find_desc(&c->vc, cookie);
> > + c->desc = to_mtk_dma_desc(&vd->tx);
> > + mtk_dma_start_tx(c);
> > + }
> > + }
> > + spin_unlock_irqrestore(&c->vc.lock, flags);
> > +}
> > +
> > +static irqreturn_t mtk_dma_rx_interrupt(int irq, void *dev_id)
> > +{
> > + struct dma_chan *chan = (struct dma_chan *)dev_id;
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > + unsigned long flags;
> > +
> > + spin_lock_irqsave(&c->vc.lock, flags);
> > + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_RX_INT_FLAG_CLR_B);
> > +
> > + mtk_dma_start_rx(c);
> > +
> > + spin_unlock_irqrestore(&c->vc.lock, flags);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static irqreturn_t mtk_dma_tx_interrupt(int irq, void *dev_id)
> > +{
> > + struct dma_chan *chan = (struct dma_chan *)dev_id;
> > + struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > + struct mtk_dma_desc *d = c->desc;
> > + unsigned long flags;
> > +
> > + spin_lock_irqsave(&c->vc.lock, flags);
> > + if (c->remain_size != 0U) {
> > + list_add_tail(&c->node, &mtkd->pending);
> > + tasklet_schedule(&mtkd->task);
> > + } else {
> > + mtk_dma_remove_virt_list(d->vd.tx.cookie, &c->vc);
> > + vchan_cookie_complete(&d->vd);
> > + }
> > + spin_unlock_irqrestore(&c->vc.lock, flags);
> > +
> > + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_TX_INT_FLAG_CLR_B);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static int mtk_dma_slave_config(struct dma_chan *chan,
> > + struct dma_slave_config *cfg)
> > +{
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > + struct mtk_dmadev *mtkd = to_mtk_dma_dev(c->vc.chan.device);
> > + int ret;
> > +
> > + c->cfg = *cfg;
> > +
> > + if (cfg->direction == DMA_DEV_TO_MEM) {
> > + unsigned int rx_len = cfg->src_addr_width * 1024;
> > +
> > + mtk_dma_chan_write(c, VFF_ADDR, cfg->src_addr);
> > + mtk_dma_chan_write(c, VFF_LEN, rx_len);
> > + mtk_dma_chan_write(c, VFF_THRE, VFF_RX_THRE(rx_len));
> > + mtk_dma_chan_write(c,
> > + VFF_INT_EN, VFF_RX_INT_EN0_B
> > + | VFF_RX_INT_EN1_B);
> > + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_RX_INT_FLAG_CLR_B);
> > + mtk_dma_chan_write(c, VFF_EN, VFF_EN_B);
> > +
> > + if (!c->requested) {
> > + c->requested = true;
> > + ret = request_irq(mtkd->dma_irq[c->dma_ch],
> > + mtk_dma_rx_interrupt,
> > + IRQF_TRIGGER_NONE,
> > + KBUILD_MODNAME, chan);
> > + if (ret < 0) {
> > + dev_err(chan->device->dev, "Can't request rx dma IRQ\n");
> > + return -EINVAL;
> > + }
> > + }
> > + } else if (cfg->direction == DMA_MEM_TO_DEV) {
> > + unsigned int tx_len = cfg->dst_addr_width * 1024;
> > +
> > + mtk_dma_chan_write(c, VFF_ADDR, cfg->dst_addr);
> > + mtk_dma_chan_write(c, VFF_LEN, tx_len);
> > + mtk_dma_chan_write(c, VFF_THRE, VFF_TX_THRE(tx_len));
> > + mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_TX_INT_FLAG_CLR_B);
> > + mtk_dma_chan_write(c, VFF_EN, VFF_EN_B);
> > +
> > + if (!c->requested) {
> > + c->requested = true;
> > + ret = request_irq(mtkd->dma_irq[c->dma_ch],
> > + mtk_dma_tx_interrupt,
> > + IRQF_TRIGGER_NONE,
> > + KBUILD_MODNAME, chan);
> > + if (ret < 0) {
> > + dev_err(chan->device->dev, "Can't request tx dma IRQ\n");
> > + return -EINVAL;
> > + }
> > + }
> > + }
> > +
> > + if (mtkd->support_33bits)
> > + mtk_dma_chan_write(c, VFF_4G_SUPPORT, VFF_4G_SUPPORT_B);
> > +
> > + if (mtk_dma_chan_read(c, VFF_EN) != VFF_EN_B) {
> > + dev_err(chan->device->dev,
> > + "config dma dir[%d] fail\n", cfg->direction);
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int mtk_dma_terminate_all(struct dma_chan *chan)
> > +{
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > + unsigned long flags;
> > +
> > + spin_lock_irqsave(&c->vc.lock, flags);
> > + list_del_init(&c->node);
> > + mtk_dma_stop(c);
> > + spin_unlock_irqrestore(&c->vc.lock, flags);
> > +
> > + return 0;
> > +}
> > +
> > +static int mtk_dma_device_pause(struct dma_chan *chan)
> > +{
> > + /* just for check caps pass */
> > + return -EINVAL;
> > +}
>
> it it possible not to register the function to the core if the
> hardware doesn't support it?
>
can't support. the function will set to cmd_pause. in 8250 serial code,
will check cmd_pause. if no the function, will can't get DMA channel.
So
the function just for this.
> > +
> > +static int mtk_dma_device_resume(struct dma_chan *chan)
> > +{
> > + /* just for check caps pass */
> > + return -EINVAL;
> > +}
>
> ditto as the above
>
> > +
> > +static void mtk_dma_free(struct mtk_dmadev *mtkd)
> > +{
> > + tasklet_kill(&mtkd->task);
> > + while (list_empty(&mtkd->ddev.channels) == 0) {
> > + struct mtk_chan *c = list_first_entry(&mtkd->ddev.channels,
> > + struct mtk_chan, vc.chan.device_node);
> > +
> > + list_del(&c->vc.chan.device_node);
> > + tasklet_kill(&c->vc.task);
> > + devm_kfree(mtkd->ddev.dev, c);
> > + }
> > +}
> > +
> > +static const struct of_device_id mtk_uart_dma_match[] = {
> > + { .compatible = "mediatek,mt6577-uart-dma", },
> > + { /* sentinel */ },
> > +};
> > +MODULE_DEVICE_TABLE(of, mtk_uart_dma_match);
> > +
> > +static int mtk_apdma_probe(struct platform_device *pdev)
> > +{
> > + struct mtk_dmadev *mtkd;
> > + struct resource *res;
> > + struct mtk_chan *c;
> > + unsigned int i;
> > + int rc;
> > +
> > + mtkd = devm_kzalloc(&pdev->dev, sizeof(*mtkd), GFP_KERNEL);
> > + if (!mtkd)
> > + return -ENOMEM;
> > +
> > + for (i = 0; i < MTK_APDMA_CHANNELS; i++) {
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, i);
> > + if (!res)
> > + return -ENODEV;
> > + mtkd->mem_base[i] = devm_ioremap_resource(&pdev->dev, res);
> > + if (IS_ERR(mtkd->mem_base[i]))
> > + return PTR_ERR(mtkd->mem_base[i]);
> > + }
> > +
> > + for (i = 0; i < MTK_APDMA_CHANNELS; i++) {
> > + mtkd->dma_irq[i] = platform_get_irq(pdev, i);
> > + if ((int)mtkd->dma_irq[i] < 0) {
> > + dev_err(&pdev->dev, "failed to get IRQ[%d]\n", i);
> > + return -EINVAL;
> > + }
> > + }
> > +
> > + mtkd->clk = devm_clk_get(&pdev->dev, NULL);
> > + if (IS_ERR(mtkd->clk)) {
> > + dev_err(&pdev->dev, "No clock specified\n");
> > + return PTR_ERR(mtkd->clk);
> > + }
> > +
> > + if (of_property_read_bool(pdev->dev.of_node, "dma-33bits")) {
> > + dev_info(&pdev->dev, "Support dma 33bits\n");
> > + mtkd->support_33bits = true;
> > + }
> > +
> > + if (mtkd->support_33bits)
> > + rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(33));
> > + else
> > + rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> > + if (rc)
> > + return rc;
> > +
> > + dma_cap_set(DMA_SLAVE, mtkd->ddev.cap_mask);
> > + mtkd->ddev.device_alloc_chan_resources = mtk_dma_alloc_chan_resources;
> > + mtkd->ddev.device_free_chan_resources = mtk_dma_free_chan_resources;
> > + mtkd->ddev.device_tx_status = mtk_dma_tx_status;
> > + mtkd->ddev.device_issue_pending = mtk_dma_issue_pending;
> > + mtkd->ddev.device_prep_slave_sg = mtk_dma_prep_slave_sg;
> > + mtkd->ddev.device_config = mtk_dma_slave_config;
> > + mtkd->ddev.device_pause = mtk_dma_device_pause;
> > + mtkd->ddev.device_resume = mtk_dma_device_resume;
> > + mtkd->ddev.device_terminate_all = mtk_dma_terminate_all;
> > + mtkd->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE);
> > + mtkd->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE);
> > + mtkd->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
> > + mtkd->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
> > + mtkd->ddev.dev = &pdev->dev;
> > + INIT_LIST_HEAD(&mtkd->ddev.channels);
> > + INIT_LIST_HEAD(&mtkd->pending);
> > +
> > + spin_lock_init(&mtkd->lock);
> > + tasklet_init(&mtkd->task, mtk_dma_sched, (unsigned long)mtkd);
> > +
> > + mtkd->dma_requests = MTK_APDMA_DEFAULT_REQUESTS;
> > + if (of_property_read_u32(pdev->dev.of_node,
> > + "dma-requests", &mtkd->dma_requests)) {
> > + dev_info(&pdev->dev,
> > + "Missing dma-requests property, using %u.\n",
> > + MTK_APDMA_DEFAULT_REQUESTS);
> > + }
> > +
> > + for (i = 0; i < MTK_APDMA_CHANNELS; i++) {
> > + c = devm_kzalloc(mtkd->ddev.dev, sizeof(*c), GFP_KERNEL);
> > + if (!c)
> > + goto err_no_dma;
> > +
> > + c->vc.desc_free = mtk_dma_desc_free;
> > + vchan_init(&c->vc, &mtkd->ddev);
> > + INIT_LIST_HEAD(&c->node);
> > + }
> > +
> > + pm_runtime_enable(&pdev->dev);
> > + pm_runtime_set_active(&pdev->dev);
> > +
> > + rc = dma_async_device_register(&mtkd->ddev);
> > + if (rc)
> > + goto rpm_disable;
> > +
> > + platform_set_drvdata(pdev, mtkd);
> > +
> > + if (pdev->dev.of_node) {
> > + mtk_dma_info.dma_cap = mtkd->ddev.cap_mask;
> > +
> > + /* Device-tree DMA controller registration */
> > + rc = of_dma_controller_register(pdev->dev.of_node,
> > + of_dma_simple_xlate,
> > + &mtk_dma_info);
>
> reusing of_dma_xlate_by_chan_id seem that also work for you.
in filter_fn function, neeg get number of dma.
>
> > + if (rc)
> > + goto dma_remove;
> > + }
> > +
> > + return rc;
> > +
> > +dma_remove:
> > + dma_async_device_unregister(&mtkd->ddev);
> > +rpm_disable:
> > + pm_runtime_disable(&pdev->dev);
> > +err_no_dma:
> > + mtk_dma_free(mtkd);
> > + return rc;
> > +}
> > +
> > +static int mtk_apdma_remove(struct platform_device *pdev)
> > +{
> > + struct mtk_dmadev *mtkd = platform_get_drvdata(pdev);
> > +
> > + if (pdev->dev.of_node)
> > + of_dma_controller_free(pdev->dev.of_node);
> > +
> > + pm_runtime_disable(&pdev->dev);
> > + pm_runtime_put_noidle(&pdev->dev);
> > +
> > + dma_async_device_unregister(&mtkd->ddev);
> > +
> > + mtk_dma_free(mtkd);
> > +
> > + return 0;
> > +}
> > +
> > +#ifdef CONFIG_PM_SLEEP
> > +static int mtk_dma_suspend(struct device *dev)
> > +{
> > + struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
> > +
> > + if (!pm_runtime_suspended(dev))
> > + mtk_dma_clk_disable(mtkd);
> > +
> > + return 0;
> > +}
> > +
> > +static int mtk_dma_resume(struct device *dev)
> > +{
> > + int ret;
> > + struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
> > +
> > + if (!pm_runtime_suspended(dev)) {
> > + ret = mtk_dma_clk_enable(mtkd);
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int mtk_dma_runtime_suspend(struct device *dev)
> > +{
> > + struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
> > +
> > + mtk_dma_clk_disable(mtkd);
> > +
> > + return 0;
> > +}
> > +
> > +static int mtk_dma_runtime_resume(struct device *dev)
> > +{
> > + int ret;
> > + struct mtk_dmadev *mtkd = dev_get_drvdata(dev);
> > +
> > + ret = mtk_dma_clk_enable(mtkd);
> > + if (ret)
> > + return ret;
> > +
> > + return 0;
> > +}
> > +
> > +#endif /* CONFIG_PM_SLEEP */
> > +
> > +static const struct dev_pm_ops mtk_dma_pm_ops = {
> > + SET_SYSTEM_SLEEP_PM_OPS(mtk_dma_suspend, mtk_dma_resume)
> > + SET_RUNTIME_PM_OPS(mtk_dma_runtime_suspend,
> > + mtk_dma_runtime_resume, NULL)
> > +};
> > +
> > +static struct platform_driver mtk_dma_driver = {
> > + .probe = mtk_apdma_probe,
> > + .remove = mtk_apdma_remove,
> > + .driver = {
> > + .name = KBUILD_MODNAME,
> > + .pm = &mtk_dma_pm_ops,
> > + .of_match_table = of_match_ptr(mtk_uart_dma_match),
> > + },
> > +};
> > +
> > +static bool mtk_dma_filter_fn(struct dma_chan *chan, void *param)
> > +{
> > + if (chan->device->dev->driver == &mtk_dma_driver.driver) {
> > + struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
> > + struct mtk_chan *c = to_mtk_dma_chan(chan);
> > + unsigned int req = *(unsigned int *)param;
> > +
> > + if (req <= mtkd->dma_requests) {
> > + c->dma_sig = req;
> > + c->dma_ch = req;
> > + return true;
> > + }
> > + }
> > + return false;
> > +}
> > +
> > +module_platform_driver(mtk_dma_driver);
> > +
> > +MODULE_DESCRIPTION("MediaTek UART APDMA Controller Driver");
> > +MODULE_AUTHOR("Long Cheng <[email protected]>");
> > +MODULE_LICENSE("GPL v2");
> > +
> > diff --git a/drivers/dma/mediatek/Kconfig b/drivers/dma/mediatek/Kconfig
> > index 27bac0b..bef436e 100644
> > --- a/drivers/dma/mediatek/Kconfig
> > +++ b/drivers/dma/mediatek/Kconfig
> > @@ -1,4 +1,15 @@
> >
> > +config DMA_MTK_UART
> > + tristate "MediaTek SoCs APDMA support for UART"
> > + depends on OF
> > + select DMA_ENGINE
> > + select DMA_VIRTUAL_CHANNELS
> > + help
> > + Support for the UART DMA engine found on MediaTek MTK SoCs.
> > + when 8250 mtk uart is enabled, and if you want to using DMA,
> > + you can enable the config. the DMA engine just only be used
> > + with MediaTek Socs.
> > +
> > config MTK_HSDMA
> > tristate "MediaTek High-Speed DMA controller support"
> > depends on ARCH_MEDIATEK || COMPILE_TEST
> > diff --git a/drivers/dma/mediatek/Makefile b/drivers/dma/mediatek/Makefile
> > index 6e778f8..2f2efd9 100644
> > --- a/drivers/dma/mediatek/Makefile
> > +++ b/drivers/dma/mediatek/Makefile
> > @@ -1 +1,2 @@
> > +obj-$(CONFIG_DMA_MTK_UART) += 8250_mtk_dma.o
> > obj-$(CONFIG_MTK_HSDMA) += mtk-hsdma.o
> > --
> > 1.7.9.5
> >
> >
> > _______________________________________________
> > Linux-mediatek mailing list
> > [email protected]
> > http://lists.infradead.org/mailman/listinfo/linux-mediatek
On Thu, Dec 6, 2018 at 1:55 AM Long Cheng <[email protected]> wrote:
>
> On Wed, 2018-12-05 at 13:07 -0800, Sean Wang wrote:
> > .
> > On Wed, Dec 5, 2018 at 1:31 AM Long Cheng <[email protected]> wrote:
> > >
> > > In DMA engine framework, add 8250 mtk dma to support it.
> > >
> > > Signed-off-by: Long Cheng <[email protected]>
> > > ---
> > > drivers/dma/mediatek/8250_mtk_dma.c | 894 +++++++++++++++++++++++++++++++++++
> > > drivers/dma/mediatek/Kconfig | 11 +
> > > drivers/dma/mediatek/Makefile | 1 +
> > > 3 files changed, 906 insertions(+)
> > > create mode 100644 drivers/dma/mediatek/8250_mtk_dma.c
> > >
> > > diff --git a/drivers/dma/mediatek/8250_mtk_dma.c b/drivers/dma/mediatek/8250_mtk_dma.c
> > > new file mode 100644
> > > index 0000000..3454679
> > > --- /dev/null
> > > +++ b/drivers/dma/mediatek/8250_mtk_dma.c
> > > @@ -0,0 +1,894 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Mediatek 8250 DMA driver.
> > > + *
> > > + * Copyright (c) 2018 MediaTek Inc.
> > > + * Author: Long Cheng <[email protected]>
> > > + */
> > > +
> > > +#include <linux/clk.h>
> > > +#include <linux/dmaengine.h>
> > > +#include <linux/dma-mapping.h>
> > > +#include <linux/err.h>
> > > +#include <linux/init.h>
> > > +#include <linux/interrupt.h>
> > > +#include <linux/list.h>
> > > +#include <linux/module.h>
> > > +#include <linux/of_dma.h>
> > > +#include <linux/of_device.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/slab.h>
> > > +#include <linux/spinlock.h>
> > > +#include <linux/pm_runtime.h>
> > > +#include <linux/iopoll.h>
> > > +
> > > +#include "../virt-dma.h"
> > > +
> > > +#define MTK_APDMA_DEFAULT_REQUESTS 127
> > > +#define MTK_APDMA_CHANNELS (CONFIG_SERIAL_8250_NR_UARTS * 2)
> > > +
> > > +#define VFF_EN_B BIT(0)
> > > +#define VFF_STOP_B BIT(0)
> > > +#define VFF_FLUSH_B BIT(0)
> > > +#define VFF_4G_SUPPORT_B BIT(0)
> > > +#define VFF_RX_INT_EN0_B BIT(0) /*rx valid size >= vff thre*/
> > > +#define VFF_RX_INT_EN1_B BIT(1)
> > > +#define VFF_TX_INT_EN_B BIT(0) /*tx left size >= vff thre*/
> > > +#define VFF_WARM_RST_B BIT(0)
> > > +#define VFF_RX_INT_FLAG_CLR_B (BIT(0) | BIT(1))
> > > +#define VFF_TX_INT_FLAG_CLR_B 0
> > > +#define VFF_STOP_CLR_B 0
> > > +#define VFF_FLUSH_CLR_B 0
> > > +#define VFF_INT_EN_CLR_B 0
> > > +#define VFF_4G_SUPPORT_CLR_B 0
> > > +
> > > +/* interrupt trigger level for tx */
> > > +#define VFF_TX_THRE(n) ((n) * 7 / 8)
> > > +/* interrupt trigger level for rx */
> > > +#define VFF_RX_THRE(n) ((n) * 3 / 4)
> > > +
> > > +#define MTK_DMA_RING_SIZE 0xffffU
> > > +/* invert this bit when wrap ring head again*/
> > > +#define MTK_DMA_RING_WRAP 0x10000U
> > > +
> > > +#define VFF_INT_FLAG 0x00
> > > +#define VFF_INT_EN 0x04
> > > +#define VFF_EN 0x08
> > > +#define VFF_RST 0x0c
> > > +#define VFF_STOP 0x10
> > > +#define VFF_FLUSH 0x14
> > > +#define VFF_ADDR 0x1c
> > > +#define VFF_LEN 0x24
> > > +#define VFF_THRE 0x28
> > > +#define VFF_WPT 0x2c
> > > +#define VFF_RPT 0x30
> > > +/*TX: the buffer size HW can read. RX: the buffer size SW can read.*/
> > > +#define VFF_VALID_SIZE 0x3c
> > > +/*TX: the buffer size SW can write. RX: the buffer size HW can write.*/
> > > +#define VFF_LEFT_SIZE 0x40
> > > +#define VFF_DEBUG_STATUS 0x50
> > > +#define VFF_4G_SUPPORT 0x54
> > > +
> > > +struct mtk_dmadev {
> > > + struct dma_device ddev;
> > > + void __iomem *mem_base[MTK_APDMA_CHANNELS];
> > > + spinlock_t lock; /* dma dev lock */
> > > + struct tasklet_struct task;
> > > + struct list_head pending;
> > > + struct clk *clk;
> > > + unsigned int dma_requests;
> > > + bool support_33bits;
> > > + unsigned int dma_irq[MTK_APDMA_CHANNELS];
> > > + struct mtk_chan *ch[MTK_APDMA_CHANNELS];
> > > +};
> > > +
> > > +struct mtk_chan {
> > > + struct virt_dma_chan vc;
> > > + struct list_head node;
> > > + struct dma_slave_config cfg;
> > > + void __iomem *base;
> > > + struct mtk_dma_desc *desc;
> > > +
> > > + bool stop;
> > > + bool requested;
> > > +
> > > + unsigned int dma_sig;
> >
> > the member can be removed as no real user would refer to it
> >
>
> Ok, i will remove it at next patch
>
> > > + unsigned int dma_ch;
> >
> > a chan_id is already included in struct dma_chan, we can reuse it
> >
>
> chan_id is start from 0. but in this driver, dma info is stored to list.
> if use port1, in filter_fn function, will set dma_ch to 2, 3(tx, rx). So
> can't using chan_id
>
if you use of_dma_xlate_by_chan_id in of_dma_controller_register, the
client device still can get the right channel with the appropriate
chan_id expressed in dmas property in dts.
> > > + unsigned int sgidx;
> >
[ ... ]
> ok, i will modify it
> > > + wpt = mtk_dma_chan_read(c, VFF_WPT);
> > > + wrap = wpt & MTK_DMA_RING_WRAP ? 0U : MTK_DMA_RING_WRAP;
> > > +
> > > + if ((wpt & (len - 1U)) + send < len)
> > > + mtk_dma_chan_write(c, VFF_WPT, wpt + send);
> > > + else
> > > + mtk_dma_chan_write(c, VFF_WPT,
> > > + ((wpt + send) & (len - 1U))
> > > + | wrap);
> > > +
> > > + c->remain_size -= send;
> >
> > I'm curious why you don't need to set up the hardware from the
> > descriptor information
> >
>
> mtk_dma_chan_write is update the hardware. remain_size is length of TX
> data.
I thought it is not enough to be a full dmaengine. if the driver only
supports single continuous data moving for device_prep_slave_sg
callback.
We could try to turn each sg item information such as source or
destination address and data length to be one part of the descriptor.
When a descriptor is being issued, and then program VFF_ADDR/LEN and
issue the data move by other VFF_* registers rather than assuming the
data portion is always the fixed as the user assignment at
mtk_dma_slave_config.