Hi,
Here we have three patches that add a DMA driver for the Ingenic JZ4780 SoC.
JZ4780 support is still in-flight.
See http://patchwork.linux-mips.org/bundle/paulburton/ci20-v3.20/
These are based on 4.0-rc1.
Apart from the channel numbers, jz4740 and jz4780 are quite different.
jz4780 has many more features in hardware.
Hence, we are unable to use the jz4740-dma driver.
V1->V2 changes
Updates for dmaengine api changes.
Add residue support.
Details in the patch commit message
ZubairLK
Alex Smith (2):
dt-bindings: dma: Add binding for jz4780-dma
dma: jz4780: add driver for the Ingenic JZ4780 DMA controller
Zubair Lutfullah Kakakhel (1):
MAINTAINERS: Add Ingenic JZ4780 DMA driver maintainer entry
.../devicetree/bindings/dma/jz4780-dma.txt | 61 ++
MAINTAINERS | 5 +
drivers/dma/Kconfig | 10 +
drivers/dma/Makefile | 1 +
drivers/dma/dma-jz4780.c | 877 +++++++++++++++++++++
include/dt-bindings/dma/jz4780-dma.h | 49 ++
6 files changed, 1003 insertions(+)
create mode 100644 Documentation/devicetree/bindings/dma/jz4780-dma.txt
create mode 100644 drivers/dma/dma-jz4780.c
create mode 100644 include/dt-bindings/dma/jz4780-dma.h
--
1.9.1
From: Alex Smith <[email protected]>
Add device tree bindings for the DMA controller on JZ4780 SoCs, used by
the dma-jz4780 driver.
Signed-off-by: Alex Smith <[email protected]>
Signed-off-by: Zubair Lutfullah Kakakhel <[email protected]>
---
V1 -> V2 None
---
.../devicetree/bindings/dma/jz4780-dma.txt | 61 ++++++++++++++++++++++
1 file changed, 61 insertions(+)
create mode 100644 Documentation/devicetree/bindings/dma/jz4780-dma.txt
diff --git a/Documentation/devicetree/bindings/dma/jz4780-dma.txt b/Documentation/devicetree/bindings/dma/jz4780-dma.txt
new file mode 100644
index 0000000..ce90011
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/jz4780-dma.txt
@@ -0,0 +1,61 @@
+* Ingenic JZ4780 DMA Controller
+
+Required properties:
+
+- compatible: Should be "ingenic,jz4780-dma"
+- reg: Should contain the DMA controller registers location and length.
+- interrupts: Should contain the interrupt specifier of the DMA controller.
+- interrupt-parent: Should be the phandle of the interrupt controller that
+- clocks: Should contain a clock specifier for the JZ4780 PDMA clock.
+- #dma-cells: Must be <3>. Number of integer cells in the dmas property of
+ DMA clients (see below).
+
+Optional properties:
+
+- ingenic,reserved-channels: Bitmask of channels to reserve for devices that
+ need a specific channel. These channels will only be assigned when explicitly
+ requested by a client. The primary use for this is channels 0 and 1, which
+ can be configured to have special behaviour for NAND/BCH when using
+ programmable firmware.
+
+Example:
+
+dma: dma@13420000 {
+ compatible = "ingenic,jz4780-dma";
+ reg = <0x13420000 0x10000>;
+
+ interrupt-parent = <&intc>;
+ interrupts = <10>;
+
+ clocks = <&cgu JZ4780_CLK_PDMA>;
+
+ #dma-cells = <3>;
+
+ ingenic,reserved-channels = <0x3>;
+};
+
+DMA clients must use the format described in dma.txt, giving a phandle to the
+DMA controller plus the following 3 integer cells:
+
+1. Transmit request type: The DMA request type for transfers to the device on
+ the allocated channel, as defined in the SoC documentation. If set to 0,
+ transfers to the device will not be allowed on the channel.
+
+2. Receive request type: The DMA request type for transfers from the device on
+ the allocated channel, as defined in the SoC documentation. If set to 0,
+ transfers from the device will not be allowed on the channel.
+
+3. Channel: If set to 0xffffffff, any available channel will be allocated for
+ the client. Otherwise, the exact channel specified will be used. The channel
+ should be reserved on the DMA controller using the ingenic,reserved-channels
+ property.
+
+Example:
+
+uart0: serial@10030000 {
+ ...
+ dmas = <&dma 0x14 0 0xffffffff
+ &dma 0 0x15 0xffffffff>;
+ dma-names = "tx", "rx";
+ ...
+};
--
1.9.1
From: Alex Smith <[email protected]>
This patch adds a driver for the DMA controller found in the Ingenic
JZ4780.
It currently does not implement any support for the programmable firmware
feature of the controller - this is not necessary for most uses. It also
does not take priority into account when allocating channels, it just
allocates the first available channel. This can be implemented later.
Signed-off-by: Alex Smith <[email protected]>
Signed-off-by: Zubair Lutfullah Kakakhel <[email protected]>
[Updated for dmaengine api changes, Add residue support, couple of minor fixes]
---
V1 -> V2
Updated for dmaengine api change See https://lkml.org/lkml/2014/10/22/585
Fixed email address
Removed context from arguments from prep_dma_cyclic and prep_slave_sg 31c1e5a135
Remove chancnt See b2c100e02f6
Removed .owner See cd166280
Added dma controller capabilites See 75dc177 and http://lwn.net/Articles/616390/
Call dma_free_irq in remove
Rename irq handler from jz4780_dma_irq to jz4780_dma_irq_handler
Fix case switch in jz4780_dma_transfer_size to make clearer.
Removed redundant check in jz4780_dma_slave_config.
Add residue support for dma-jz4780
Removed reduntant print after devm_kzalloc.
---
drivers/dma/Kconfig | 10 +
drivers/dma/Makefile | 1 +
drivers/dma/dma-jz4780.c | 877 +++++++++++++++++++++++++++++++++++
include/dt-bindings/dma/jz4780-dma.h | 49 ++
4 files changed, 937 insertions(+)
create mode 100644 drivers/dma/dma-jz4780.c
create mode 100644 include/dt-bindings/dma/jz4780-dma.h
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index a874b6e..ce09734 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -358,6 +358,16 @@ config DMA_JZ4740
select DMA_ENGINE
select DMA_VIRTUAL_CHANNELS
+config DMA_JZ4780
+ tristate "JZ4780 DMA support"
+ depends on MACH_JZ4780
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+ help
+ This selects support for the DMA controller in Ingenic JZ4780 SoCs.
+ If you have a board based on such a SoC and wish to use DMA for
+ devices which can use the DMA controller, say Y or M here.
+
config K3_DMA
tristate "Hisilicon K3 DMA support"
depends on ARCH_HI3xxx
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index f915f61..af239e7 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_DMA_OMAP) += omap-dma.o
obj-$(CONFIG_DMA_BCM2835) += bcm2835-dma.o
obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o
+obj-$(CONFIG_DMA_JZ4780) += dma-jz4780.o
obj-$(CONFIG_TI_CPPI41) += cppi41.o
obj-$(CONFIG_K3_DMA) += k3dma.o
obj-$(CONFIG_MOXART_DMA) += moxart-dma.o
diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
new file mode 100644
index 0000000..db9ff05
--- /dev/null
+++ b/drivers/dma/dma-jz4780.c
@@ -0,0 +1,877 @@
+/*
+ * Ingenic JZ4780 DMA controller
+ *
+ * Copyright (c) 2015 Imagination Technologies
+ * Author: Alex Smith <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/dmapool.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "dmaengine.h"
+#include "virt-dma.h"
+
+#define JZ_DMA_NR_CHANNELS 32
+
+/* Global registers. */
+#define JZ_DMA_REG_DMAC 0x1000
+#define JZ_DMA_REG_DIRQP 0x1004
+#define JZ_DMA_REG_DDR 0x1008
+#define JZ_DMA_REG_DDRS 0x100c
+#define JZ_DMA_REG_DMACP 0x101c
+#define JZ_DMA_REG_DSIRQP 0x1020
+#define JZ_DMA_REG_DSIRQM 0x1024
+#define JZ_DMA_REG_DCIRQP 0x1028
+#define JZ_DMA_REG_DCIRQM 0x102c
+
+/* Per-channel registers. */
+#define JZ_DMA_REG_DSA(n) (0x00 + (n) * 0x20)
+#define JZ_DMA_REG_DTA(n) (0x04 + (n) * 0x20)
+#define JZ_DMA_REG_DTC(n) (0x08 + (n) * 0x20)
+#define JZ_DMA_REG_DRT(n) (0x0c + (n) * 0x20)
+#define JZ_DMA_REG_DCS(n) (0x10 + (n) * 0x20)
+#define JZ_DMA_REG_DCM(n) (0x14 + (n) * 0x20)
+#define JZ_DMA_REG_DDA(n) (0x18 + (n) * 0x20)
+#define JZ_DMA_REG_DSD(n) (0x1c + (n) * 0x20)
+
+#define JZ_DMA_DMAC_DMAE BIT(0)
+#define JZ_DMA_DMAC_AR BIT(2)
+#define JZ_DMA_DMAC_HLT BIT(3)
+#define JZ_DMA_DMAC_FMSC BIT(31)
+
+#define JZ_DMA_DRT_AUTO 0x8
+
+#define JZ_DMA_DCS_CTE BIT(0)
+#define JZ_DMA_DCS_HLT BIT(2)
+#define JZ_DMA_DCS_TT BIT(3)
+#define JZ_DMA_DCS_AR BIT(4)
+#define JZ_DMA_DCS_DES8 BIT(30)
+
+#define JZ_DMA_DCM_LINK BIT(0)
+#define JZ_DMA_DCM_TIE BIT(1)
+#define JZ_DMA_DCM_STDE BIT(2)
+#define JZ_DMA_DCM_TSZ_SHIFT 8
+#define JZ_DMA_DCM_TSZ_MASK (0x7 << JZ_DMA_DCM_TSZ_SHIFT)
+#define JZ_DMA_DCM_DP_SHIFT 12
+#define JZ_DMA_DCM_SP_SHIFT 14
+#define JZ_DMA_DCM_DAI BIT(22)
+#define JZ_DMA_DCM_SAI BIT(23)
+
+#define JZ_DMA_SIZE_4_BYTE 0x0
+#define JZ_DMA_SIZE_1_BYTE 0x1
+#define JZ_DMA_SIZE_2_BYTE 0x2
+#define JZ_DMA_SIZE_16_BYTE 0x3
+#define JZ_DMA_SIZE_32_BYTE 0x4
+#define JZ_DMA_SIZE_64_BYTE 0x5
+#define JZ_DMA_SIZE_128_BYTE 0x6
+
+#define JZ_DMA_WIDTH_32_BIT 0x0
+#define JZ_DMA_WIDTH_8_BIT 0x1
+#define JZ_DMA_WIDTH_16_BIT 0x2
+
+#define JZ_DMA_BUSWIDTHS (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
+ BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
+ BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
+
+/**
+ * struct jz4780_dma_hwdesc - descriptor structure read by the DMA controller.
+ * @dcm: value for the DCM (channel command) register
+ * @dsa: source address
+ * @dta: target address
+ * @dtc: transfer count (number of blocks of the transfer size specified in DCM
+ * to transfer) in the low 24 bits, offset of the next descriptor from the
+ * descriptor base address in the upper 8 bits.
+ * @sd: target/source stride difference (in stride transfer mode).
+ * @drt: request type
+ */
+struct jz4780_dma_hwdesc {
+ uint32_t dcm;
+ uint32_t dsa;
+ uint32_t dta;
+ uint32_t dtc;
+ uint32_t sd;
+ uint32_t drt;
+ uint32_t reserved[2];
+};
+
+/* Size of allocations for hardware descriptor blocks. */
+#define JZ_DMA_DESC_BLOCK_SIZE PAGE_SIZE
+#define JZ_DMA_MAX_DESC \
+ (JZ_DMA_DESC_BLOCK_SIZE / sizeof(struct jz4780_dma_hwdesc))
+
+struct jz4780_dma_desc {
+ struct virt_dma_desc vdesc;
+
+ struct jz4780_dma_hwdesc *desc;
+ dma_addr_t desc_phys;
+ unsigned int count;
+ enum dma_transaction_type type;
+ uint32_t status;
+};
+
+struct jz4780_dma_chan {
+ struct virt_dma_chan vchan;
+ unsigned int id;
+ struct dma_pool *desc_pool;
+
+ uint32_t tx_type;
+ uint32_t rx_type;
+ uint32_t transfer_shift;
+ struct dma_slave_config config;
+
+ struct jz4780_dma_desc *desc;
+ unsigned int curr_hwdesc;
+};
+
+struct jz4780_dma_dev {
+ struct dma_device dma_device;
+ void __iomem *base;
+ struct clk *clk;
+ unsigned int irq;
+
+ uint32_t chan_reserved;
+ struct jz4780_dma_chan chan[JZ_DMA_NR_CHANNELS];
+};
+
+struct jz4780_dma_data {
+ uint32_t tx_type;
+ uint32_t rx_type;
+ int channel;
+};
+
+static inline struct jz4780_dma_chan *to_jz4780_dma_chan(struct dma_chan *chan)
+{
+ return container_of(chan, struct jz4780_dma_chan, vchan.chan);
+}
+
+static inline struct jz4780_dma_desc *to_jz4780_dma_desc(
+ struct virt_dma_desc *vdesc)
+{
+ return container_of(vdesc, struct jz4780_dma_desc, vdesc);
+}
+
+static inline struct jz4780_dma_dev *jz4780_dma_chan_parent(
+ struct jz4780_dma_chan *jzchan)
+{
+ return container_of(jzchan->vchan.chan.device, struct jz4780_dma_dev,
+ dma_device);
+}
+
+static inline uint32_t jz4780_dma_readl(struct jz4780_dma_dev *jzdma,
+ unsigned int reg)
+{
+ return readl(jzdma->base + reg);
+}
+
+static inline void jz4780_dma_writel(struct jz4780_dma_dev *jzdma,
+ unsigned int reg, uint32_t val)
+{
+ writel(val, jzdma->base + reg);
+}
+
+static struct jz4780_dma_desc *jz4780_dma_desc_alloc(
+ struct jz4780_dma_chan *jzchan, unsigned int count,
+ enum dma_transaction_type type)
+{
+ struct jz4780_dma_desc *desc;
+
+ if (count > JZ_DMA_MAX_DESC)
+ return NULL;
+
+ desc = kzalloc(sizeof(*desc), GFP_ATOMIC);
+ if (!desc)
+ return NULL;
+
+ desc->desc = dma_pool_alloc(jzchan->desc_pool, GFP_ATOMIC,
+ &desc->desc_phys);
+ if (!desc->desc) {
+ kfree(desc);
+ return NULL;
+ }
+
+ desc->count = count;
+ desc->type = type;
+ return desc;
+}
+
+static void jz4780_dma_desc_free(struct virt_dma_desc *vdesc)
+{
+ struct jz4780_dma_desc *desc = to_jz4780_dma_desc(vdesc);
+ struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(vdesc->tx.chan);
+
+ dma_pool_free(jzchan->desc_pool, desc->desc, desc->desc_phys);
+ kfree(desc);
+}
+
+static uint32_t jz4780_dma_width(enum dma_slave_buswidth width)
+{
+ switch (width) {
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ return JZ_DMA_WIDTH_8_BIT;
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ return JZ_DMA_WIDTH_16_BIT;
+ default:
+ return JZ_DMA_WIDTH_32_BIT;
+ }
+}
+
+static uint32_t jz4780_dma_transfer_size(unsigned long val, int *ord)
+{
+ *ord = ffs(val) - 1;
+
+ /* 8 byte transfer sizes unsupported so fall back on 4. */
+ if (*ord == 3)
+ *ord = 2;
+ else if (*ord > 7)
+ *ord = 7;
+
+ switch (*ord) {
+ case 0:
+ return JZ_DMA_SIZE_1_BYTE;
+ case 1:
+ return JZ_DMA_SIZE_2_BYTE;
+ case 2:
+ return JZ_DMA_SIZE_4_BYTE;
+ case 4:
+ return JZ_DMA_SIZE_16_BYTE;
+ case 5:
+ return JZ_DMA_SIZE_32_BYTE;
+ case 6:
+ return JZ_DMA_SIZE_64_BYTE;
+ case 7:
+ return JZ_DMA_SIZE_128_BYTE;
+ default:
+ WARN_ON(1);
+ return -1; /* Can never happen. See previous comment */
+ }
+}
+
+static void jz4780_dma_setup_hwdesc(struct jz4780_dma_chan *jzchan,
+ struct jz4780_dma_hwdesc *desc, dma_addr_t addr, size_t len)
+{
+ struct dma_slave_config *config = &jzchan->config;
+ uint32_t width, maxburst, tsz;
+ int ord;
+
+ if (config->direction == DMA_MEM_TO_DEV) {
+ desc->dcm = JZ_DMA_DCM_SAI;
+ desc->dsa = addr;
+ desc->dta = config->dst_addr;
+ desc->drt = jzchan->tx_type;
+
+ width = config->dst_addr_width;
+ maxburst = config->dst_maxburst;
+ } else {
+ desc->dcm = JZ_DMA_DCM_DAI;
+ desc->dsa = config->src_addr;
+ desc->dta = addr;
+ desc->drt = jzchan->rx_type;
+
+ width = config->src_addr_width;
+ maxburst = config->src_maxburst;
+ }
+
+ /*
+ * This calculates the maximum transfer size that can be used with the
+ * given address, length, width and maximum burst size. The address
+ * must be aligned to the transfer size, the total length must be
+ * divisible by the transfer size, and we must not use more than the
+ * maximum burst specified by the user.
+ */
+ tsz = jz4780_dma_transfer_size(addr | len | (width * maxburst), &ord);
+ jzchan->transfer_shift = ord;
+ width = jz4780_dma_width(width);
+
+ desc->dcm |= tsz << JZ_DMA_DCM_TSZ_SHIFT;
+ desc->dcm |= width << JZ_DMA_DCM_SP_SHIFT;
+ desc->dcm |= width << JZ_DMA_DCM_DP_SHIFT;
+
+ desc->dtc = len >> ord;
+}
+
+static struct dma_async_tx_descriptor *jz4780_dma_prep_slave_sg(
+ struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
+ enum dma_transfer_direction direction, unsigned long flags)
+{
+ struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
+ struct jz4780_dma_desc *desc;
+ unsigned int i;
+
+ desc = jz4780_dma_desc_alloc(jzchan, sg_len, DMA_SLAVE);
+ if (!desc)
+ return NULL;
+
+ for (i = 0; i < sg_len; i++) {
+ jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i],
+ sg_dma_address(&sgl[i]),
+ sg_dma_len(&sgl[i]));
+
+ desc->desc[i].dcm |= JZ_DMA_DCM_TIE;
+
+ if (i != (sg_len - 1)) {
+ /* Automatically proceeed to the next descriptor. */
+ desc->desc[i].dcm |= JZ_DMA_DCM_LINK;
+
+ /*
+ * The upper 8 bits of the DTC field in the descriptor
+ * must be set to (offset from descriptor base of next
+ * descriptor >> 4).
+ */
+ desc->desc[i].dtc |=
+ (((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
+ }
+ }
+
+ return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
+}
+
+static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_cyclic(
+ struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len, enum dma_transfer_direction direction,
+ unsigned long flags)
+{
+ struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
+ struct jz4780_dma_desc *desc;
+ unsigned int periods, i;
+
+ if (buf_len % period_len)
+ return NULL;
+
+ periods = buf_len / period_len;
+
+ desc = jz4780_dma_desc_alloc(jzchan, periods, DMA_CYCLIC);
+ if (!desc)
+ return NULL;
+
+ for (i = 0; i < periods; i++) {
+ jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i], buf_addr,
+ period_len);
+ buf_addr += period_len;
+
+ /*
+ * Set the link bit to indicate that the controller should
+ * automatically proceed to the next descriptor. In
+ * jz4780_dma_begin(), this will be cleared if we need to issue
+ * an interrupt after each period.
+ */
+ desc->desc[i].dcm |= JZ_DMA_DCM_TIE | JZ_DMA_DCM_LINK;
+
+ /*
+ * The upper 8 bits of the DTC field in the descriptor must be
+ * set to (offset from descriptor base of next descriptor >> 4).
+ * If this is the last descriptor, link it back to the first,
+ * i.e. leave offset set to 0, otherwise point to the next one.
+ */
+ if (i != (periods - 1)) {
+ desc->desc[i].dtc |=
+ (((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
+ }
+ }
+
+ return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
+}
+
+struct dma_async_tx_descriptor *jz4780_dma_prep_dma_memcpy(
+ struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+ size_t len, unsigned long flags)
+{
+ struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
+ struct jz4780_dma_desc *desc;
+ uint32_t tsz;
+ int ord;
+
+ desc = jz4780_dma_desc_alloc(jzchan, 1, DMA_MEMCPY);
+ if (!desc)
+ return NULL;
+
+ tsz = jz4780_dma_transfer_size(dest | src | len, &ord);
+
+ desc->desc[0].dsa = src;
+ desc->desc[0].dta = dest;
+ desc->desc[0].drt = JZ_DMA_DRT_AUTO;
+ desc->desc[0].dcm = JZ_DMA_DCM_TIE | JZ_DMA_DCM_SAI | JZ_DMA_DCM_DAI |
+ tsz << JZ_DMA_DCM_TSZ_SHIFT |
+ JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_SP_SHIFT |
+ JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_DP_SHIFT;
+ desc->desc[0].dtc = len >> ord;
+
+ return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
+}
+
+static void jz4780_dma_begin(struct jz4780_dma_chan *jzchan)
+{
+ struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
+ struct virt_dma_desc *vdesc;
+ unsigned int i;
+ dma_addr_t desc_phys;
+
+ if (!jzchan->desc) {
+ vdesc = vchan_next_desc(&jzchan->vchan);
+ if (!vdesc)
+ return;
+
+ list_del(&vdesc->node);
+
+ jzchan->desc = to_jz4780_dma_desc(vdesc);
+ jzchan->curr_hwdesc = 0;
+
+ if (jzchan->desc->type == DMA_CYCLIC && vdesc->tx.callback) {
+ /*
+ * The DMA controller doesn't support triggering an
+ * interrupt after processing each descriptor, only
+ * after processing an entire terminated list of
+ * descriptors. For a cyclic DMA setup the list of
+ * descriptors is not terminated so we can never get an
+ * interrupt.
+ *
+ * If the user requested a callback for a cyclic DMA
+ * setup then we workaround this hardware limitation
+ * here by degrading to a set of unlinked descriptors
+ * which we will submit in sequence in response to the
+ * completion of processing the previous descriptor.
+ */
+ for (i = 0; i < jzchan->desc->count; i++)
+ jzchan->desc->desc[i].dcm &= ~JZ_DMA_DCM_LINK;
+ }
+ } else {
+ /*
+ * There is an existing transfer, therefore this must be one
+ * for which we unlinked the descriptors above. Advance to the
+ * next one in the list.
+ */
+ jzchan->curr_hwdesc =
+ (jzchan->curr_hwdesc + 1) % jzchan->desc->count;
+ }
+
+ /* Use 8-word descriptors. */
+ jz4780_dma_writel(jzdma, JZ_DMA_REG_DCS(jzchan->id), JZ_DMA_DCS_DES8);
+
+ /* Write descriptor address and initiate descriptor fetch. */
+ desc_phys = jzchan->desc->desc_phys +
+ (jzchan->curr_hwdesc * sizeof(*jzchan->desc->desc));
+ jz4780_dma_writel(jzdma, JZ_DMA_REG_DDA(jzchan->id), desc_phys);
+ jz4780_dma_writel(jzdma, JZ_DMA_REG_DDRS, BIT(jzchan->id));
+
+ /* Enable the channel. */
+ jz4780_dma_writel(jzdma, JZ_DMA_REG_DCS(jzchan->id),
+ JZ_DMA_DCS_DES8 | JZ_DMA_DCS_CTE);
+}
+
+static void jz4780_dma_issue_pending(struct dma_chan *chan)
+{
+ struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&jzchan->vchan.lock, flags);
+
+ if (vchan_issue_pending(&jzchan->vchan) && !jzchan->desc)
+ jz4780_dma_begin(jzchan);
+
+ spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
+}
+
+static int jz4780_dma_terminate_all(struct jz4780_dma_chan *jzchan)
+{
+ struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ spin_lock_irqsave(&jzchan->vchan.lock, flags);
+
+ /* Clear the DMA status and stop the transfer. */
+ jz4780_dma_writel(jzdma, JZ_DMA_REG_DCS(jzchan->id), 0);
+ if (jzchan->desc) {
+ jz4780_dma_desc_free(&jzchan->desc->vdesc);
+ jzchan->desc = NULL;
+ }
+
+ vchan_get_all_descriptors(&jzchan->vchan, &head);
+
+ spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
+
+ vchan_dma_desc_free_list(&jzchan->vchan, &head);
+ return 0;
+}
+
+static int jz4780_dma_slave_config(struct jz4780_dma_chan *jzchan,
+ const struct dma_slave_config *config)
+{
+ if ((config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
+ || (config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES))
+ return -EINVAL;
+
+ /* Copy the reset of the slave configuration, it is used later. */
+ memcpy(&jzchan->config, config, sizeof(jzchan->config));
+
+ return 0;
+}
+
+static size_t jz4780_dma_desc_residue(struct jz4780_dma_chan *jzchan,
+ struct jz4780_dma_desc *desc, unsigned int next_sg)
+{
+ struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
+ unsigned int residue, count;
+ unsigned int i;
+
+ residue = 0;
+
+ for (i = next_sg; i < desc->count; i++)
+ residue += desc->desc[i].dtc << jzchan->transfer_shift;
+
+ if (next_sg != 0) {
+ count = jz4780_dma_readl(jzdma,
+ JZ_DMA_REG_DTC(jzchan->id));
+ residue += count << jzchan->transfer_shift;
+ }
+
+ return residue;
+}
+
+static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie, struct dma_tx_state *txstate)
+{
+ struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
+ struct virt_dma_desc *vdesc;
+ enum dma_status status;
+ unsigned long flags;
+
+ status = dma_cookie_status(chan, cookie, txstate);
+ if (status == DMA_COMPLETE)
+ return status;
+
+ spin_lock_irqsave(&jzchan->vchan.lock, flags);
+
+ vdesc = vchan_find_desc(&jzchan->vchan, cookie);
+ if (vdesc) {
+ /* On the issued list, so hasn't been processed yet */
+ txstate->residue = jz4780_dma_desc_residue(jzchan,
+ to_jz4780_dma_desc(vdesc), 0);
+ } else if (cookie == jzchan->desc->vdesc.tx.cookie) {
+ txstate->residue = jz4780_dma_desc_residue(jzchan, jzchan->desc,
+ (jzchan->curr_hwdesc + 1) % jzchan->desc->count);
+ } else
+ txstate->residue = 0;
+
+ if (vdesc && jzchan->desc && vdesc == &jzchan->desc->vdesc
+ && jzchan->desc->status & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT))
+ status = DMA_ERROR;
+
+ spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
+ return status;
+}
+
+static void jz4780_dma_chan_irq(struct jz4780_dma_dev *jzdma,
+ struct jz4780_dma_chan *jzchan)
+{
+ uint32_t dcs;
+
+ spin_lock(&jzchan->vchan.lock);
+
+ dcs = jz4780_dma_readl(jzdma, JZ_DMA_REG_DCS(jzchan->id));
+ jz4780_dma_writel(jzdma, JZ_DMA_REG_DCS(jzchan->id), 0);
+
+ if (dcs & JZ_DMA_DCS_AR) {
+ dev_warn(&jzchan->vchan.chan.dev->device,
+ "address error (DCS=0x%x)\n", dcs);
+ }
+
+ if (dcs & JZ_DMA_DCS_HLT) {
+ dev_warn(&jzchan->vchan.chan.dev->device,
+ "channel halt (DCS=0x%x)\n", dcs);
+ }
+
+ if (jzchan->desc) {
+ jzchan->desc->status = dcs;
+
+ if ((dcs & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT)) == 0) {
+ if (jzchan->desc->type == DMA_CYCLIC) {
+ vchan_cyclic_callback(&jzchan->desc->vdesc);
+ } else {
+ vchan_cookie_complete(&jzchan->desc->vdesc);
+ jzchan->desc = NULL;
+ }
+
+ jz4780_dma_begin(jzchan);
+ }
+ } else {
+ dev_err(&jzchan->vchan.chan.dev->device,
+ "channel IRQ with no active transfer\n");
+ }
+
+ spin_unlock(&jzchan->vchan.lock);
+}
+
+static irqreturn_t jz4780_dma_irq_handler(int irq, void *data)
+{
+ struct jz4780_dma_dev *jzdma = data;
+ uint32_t pending, dmac;
+ int i;
+
+ pending = jz4780_dma_readl(jzdma, JZ_DMA_REG_DIRQP);
+
+ for (i = 0; i < JZ_DMA_NR_CHANNELS; i++) {
+ if (!(pending & (1<<i)))
+ continue;
+
+ jz4780_dma_chan_irq(jzdma, &jzdma->chan[i]);
+ }
+
+ /* Clear halt and address error status of all channels. */
+ dmac = jz4780_dma_readl(jzdma, JZ_DMA_REG_DMAC);
+ dmac &= ~(JZ_DMA_DMAC_HLT | JZ_DMA_DMAC_AR);
+ jz4780_dma_writel(jzdma, JZ_DMA_REG_DMAC, dmac);
+
+ /* Clear interrupt pending status. */
+ jz4780_dma_writel(jzdma, JZ_DMA_REG_DIRQP, 0);
+
+ return IRQ_HANDLED;
+}
+
+static int jz4780_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
+
+ jzchan->desc_pool = dma_pool_create(dev_name(&chan->dev->device),
+ chan->device->dev,
+ JZ_DMA_DESC_BLOCK_SIZE,
+ PAGE_SIZE, 0);
+ if (!jzchan->desc_pool) {
+ dev_err(&chan->dev->device,
+ "failed to allocate descriptor pool\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void jz4780_dma_free_chan_resources(struct dma_chan *chan)
+{
+ struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
+
+ vchan_free_chan_resources(&jzchan->vchan);
+ dma_pool_destroy(jzchan->desc_pool);
+ jzchan->desc_pool = NULL;
+}
+
+static bool jz4780_dma_filter_fn(struct dma_chan *chan, void *param)
+{
+ struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
+ struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
+ struct jz4780_dma_data *data = param;
+
+ if (data->channel > -1) {
+ if (data->channel != jzchan->id)
+ return false;
+ } else if (jzdma->chan_reserved & BIT(jzchan->id)) {
+ return false;
+ }
+
+ jzchan->tx_type = data->tx_type;
+ jzchan->rx_type = data->rx_type;
+
+ return true;
+}
+
+static struct dma_chan *jz4780_of_dma_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct jz4780_dma_dev *jzdma = ofdma->of_dma_data;
+ dma_cap_mask_t mask = jzdma->dma_device.cap_mask;
+ struct jz4780_dma_data data;
+
+ if (dma_spec->args_count != 3)
+ return NULL;
+
+ data.tx_type = dma_spec->args[0];
+ data.rx_type = dma_spec->args[1];
+ data.channel = dma_spec->args[2];
+
+ if (data.channel > -1) {
+ if (data.channel >= JZ_DMA_NR_CHANNELS) {
+ dev_err(jzdma->dma_device.dev,
+ "device requested non-existant channel %u\n",
+ data.channel);
+ return NULL;
+ }
+
+ /* Can only select a channel marked as reserved. */
+ if (!(jzdma->chan_reserved & BIT(data.channel))) {
+ dev_err(jzdma->dma_device.dev,
+ "device requested unreserved channel %u\n",
+ data.channel);
+ return NULL;
+ }
+ }
+
+ return dma_request_channel(mask, jz4780_dma_filter_fn, &data);
+}
+
+static int jz4780_dma_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct jz4780_dma_dev *jzdma;
+ struct jz4780_dma_chan *jzchan;
+ struct dma_device *dd;
+ struct resource *res;
+ int i, ret;
+
+ jzdma = devm_kzalloc(dev, sizeof(*jzdma), GFP_KERNEL);
+ if (!jzdma)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, jzdma);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "failed to get I/O memory\n");
+ return -EINVAL;
+ }
+
+ jzdma->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(jzdma->base))
+ return PTR_ERR(jzdma->base);
+
+ jzdma->irq = platform_get_irq(pdev, 0);
+ if (jzdma->irq < 0) {
+ dev_err(dev, "failed to get IRQ: %d\n", ret);
+ return jzdma->irq;
+ }
+
+ ret = devm_request_irq(dev, jzdma->irq, jz4780_dma_irq_handler, 0,
+ dev_name(dev), jzdma);
+ if (ret) {
+ dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq);
+ return -EINVAL;
+ }
+
+ jzdma->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(jzdma->clk)) {
+ dev_err(dev, "failed to get clock\n");
+ return PTR_ERR(jzdma->clk);
+ }
+
+ clk_prepare_enable(jzdma->clk);
+
+ /* Property is optional, if it doesn't exist the value will remain 0. */
+ of_property_read_u32_index(dev->of_node, "ingenic,reserved-channels",
+ 0, &jzdma->chan_reserved);
+
+ dd = &jzdma->dma_device;
+
+ dma_cap_set(DMA_MEMCPY, dd->cap_mask);
+ dma_cap_set(DMA_SLAVE, dd->cap_mask);
+ dma_cap_set(DMA_CYCLIC, dd->cap_mask);
+
+ dd->dev = dev;
+ dd->copy_align = 2; /* 2^2 = 4 byte alignment */
+ dd->device_alloc_chan_resources = jz4780_dma_alloc_chan_resources;
+ dd->device_free_chan_resources = jz4780_dma_free_chan_resources;
+ dd->device_prep_slave_sg = jz4780_dma_prep_slave_sg;
+ dd->device_prep_dma_cyclic = jz4780_dma_prep_dma_cyclic;
+ dd->device_prep_dma_memcpy = jz4780_dma_prep_dma_memcpy;
+ dd->device_config = jz4780_dma_slave_config;
+ dd->device_terminate_all = jz4780_dma_terminate_all;
+ dd->device_tx_status = jz4780_dma_tx_status;
+ dd->device_issue_pending = jz4780_dma_issue_pending;
+ dd->src_addr_widths = JZ_DMA_BUSWIDTHS;
+ dd->dst_addr_widths = JZ_DMA_BUSWIDTHS;
+ dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+
+
+ /*
+ * Enable DMA controller, mark all channels as not programmable.
+ * Also set the FMSC bit - it increases MSC performance, so it makes
+ * little sense not to enable it.
+ */
+ jz4780_dma_writel(jzdma, JZ_DMA_REG_DMAC,
+ JZ_DMA_DMAC_DMAE | JZ_DMA_DMAC_FMSC);
+ jz4780_dma_writel(jzdma, JZ_DMA_REG_DMACP, 0);
+
+ INIT_LIST_HEAD(&dd->channels);
+
+ for (i = 0; i < JZ_DMA_NR_CHANNELS; i++) {
+ jzchan = &jzdma->chan[i];
+ jzchan->id = i;
+
+ vchan_init(&jzchan->vchan, dd);
+ jzchan->vchan.desc_free = jz4780_dma_desc_free;
+ }
+
+ ret = dma_async_device_register(dd);
+ if (ret) {
+ dev_err(dev, "failed to register device\n");
+ goto err_disable_clk;
+ }
+
+ /* Register with OF DMA helpers. */
+ ret = of_dma_controller_register(dev->of_node, jz4780_of_dma_xlate,
+ jzdma);
+ if (ret) {
+ dev_err(dev, "failed to register OF DMA controller\n");
+ goto err_unregister_dev;
+ }
+
+ dev_info(dev, "JZ4780 DMA controller initialised\n");
+ return 0;
+
+err_unregister_dev:
+ dma_async_device_unregister(dd);
+
+err_disable_clk:
+ clk_disable_unprepare(jzdma->clk);
+ return ret;
+}
+
+static int jz4780_dma_remove(struct platform_device *pdev)
+{
+ struct jz4780_dma_dev *jzdma = platform_get_drvdata(pdev);
+
+ of_dma_controller_free(pdev->dev.of_node);
+ devm_free_irq(&pdev->dev, jzdma->irq, jzdma);
+ dma_async_device_unregister(&jzdma->dma_device);
+ return 0;
+}
+
+static const struct of_device_id jz4780_dma_dt_match[] = {
+ { .compatible = "ingenic,jz4780-dma", .data = NULL },
+ {},
+};
+MODULE_DEVICE_TABLE(of, jz4780_dma_dt_match);
+
+static struct platform_driver jz4780_dma_driver = {
+ .probe = jz4780_dma_probe,
+ .remove = jz4780_dma_remove,
+ .driver = {
+ .name = "jz4780-dma",
+ .of_match_table = of_match_ptr(jz4780_dma_dt_match),
+ },
+};
+
+static int __init jz4780_dma_init(void)
+{
+ return platform_driver_register(&jz4780_dma_driver);
+}
+subsys_initcall(jz4780_dma_init);
+
+static void __exit jz4780_dma_exit(void)
+{
+ platform_driver_unregister(&jz4780_dma_driver);
+}
+module_exit(jz4780_dma_exit);
+
+MODULE_AUTHOR("Alex Smith <[email protected]>");
+MODULE_DESCRIPTION("Ingenic JZ4780 DMA controller driver");
+MODULE_LICENSE("GPL");
diff --git a/include/dt-bindings/dma/jz4780-dma.h b/include/dt-bindings/dma/jz4780-dma.h
new file mode 100644
index 0000000..df017fd
--- /dev/null
+++ b/include/dt-bindings/dma/jz4780-dma.h
@@ -0,0 +1,49 @@
+#ifndef __DT_BINDINGS_DMA_JZ4780_DMA_H__
+#define __DT_BINDINGS_DMA_JZ4780_DMA_H__
+
+/*
+ * Request type numbers for the JZ4780 DMA controller (written to the DRTn
+ * register for the channel).
+ */
+#define JZ4780_DMA_I2S1_TX 0x4
+#define JZ4780_DMA_I2S1_RX 0x5
+#define JZ4780_DMA_I2S0_TX 0x6
+#define JZ4780_DMA_I2S0_RX 0x7
+#define JZ4780_DMA_AUTO 0x8
+#define JZ4780_DMA_SADC_RX 0x9
+#define JZ4780_DMA_UART4_TX 0xc
+#define JZ4780_DMA_UART4_RX 0xd
+#define JZ4780_DMA_UART3_TX 0xe
+#define JZ4780_DMA_UART3_RX 0xf
+#define JZ4780_DMA_UART2_TX 0x10
+#define JZ4780_DMA_UART2_RX 0x11
+#define JZ4780_DMA_UART1_TX 0x12
+#define JZ4780_DMA_UART1_RX 0x13
+#define JZ4780_DMA_UART0_TX 0x14
+#define JZ4780_DMA_UART0_RX 0x15
+#define JZ4780_DMA_SSI0_TX 0x16
+#define JZ4780_DMA_SSI0_RX 0x17
+#define JZ4780_DMA_SSI1_TX 0x18
+#define JZ4780_DMA_SSI1_RX 0x19
+#define JZ4780_DMA_MSC0_TX 0x1a
+#define JZ4780_DMA_MSC0_RX 0x1b
+#define JZ4780_DMA_MSC1_TX 0x1c
+#define JZ4780_DMA_MSC1_RX 0x1d
+#define JZ4780_DMA_MSC2_TX 0x1e
+#define JZ4780_DMA_MSC2_RX 0x1f
+#define JZ4780_DMA_PCM0_TX 0x20
+#define JZ4780_DMA_PCM0_RX 0x21
+#define JZ4780_DMA_SMB0_TX 0x24
+#define JZ4780_DMA_SMB0_RX 0x25
+#define JZ4780_DMA_SMB1_TX 0x26
+#define JZ4780_DMA_SMB1_RX 0x27
+#define JZ4780_DMA_SMB2_TX 0x28
+#define JZ4780_DMA_SMB2_RX 0x29
+#define JZ4780_DMA_SMB3_TX 0x2a
+#define JZ4780_DMA_SMB3_RX 0x2b
+#define JZ4780_DMA_SMB4_TX 0x2c
+#define JZ4780_DMA_SMB4_RX 0x2d
+#define JZ4780_DMA_DES_TX 0x2e
+#define JZ4780_DMA_DES_RX 0x2f
+
+#endif /* __DT_BINDINGS_DMA_JZ4780_DMA_H__ */
--
1.9.1
Signed-off-by: Zubair Lutfullah Kakakhel <[email protected]>
---
MAINTAINERS | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index ddc5a8c..be98874 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4962,6 +4962,11 @@ W: http://industrypack.sourceforge.net
S: Maintained
F: drivers/ipack/
+INGENIC JZ4780 DMA Driver
+M: Zubair Lutfullah Kakakhel <[email protected]>
+S: Maintained
+F: drivers/dma/dma-jz4780.c
+
INTEGRITY MEASUREMENT ARCHITECTURE (IMA)
M: Mimi Zohar <[email protected]>
M: Dmitry Kasatkin <[email protected]>
--
1.9.1
On 24/02/15 18:08, Zubair Lutfullah Kakakhel wrote:
> From: Alex Smith <[email protected]>
>
> Add device tree bindings for the DMA controller on JZ4780 SoCs, used by
> the dma-jz4780 driver.
>
> Signed-off-by: Alex Smith <[email protected]>
> Signed-off-by: Zubair Lutfullah Kakakhel <[email protected]>
>
> ---
> V1 -> V2 None
> ---
> .../devicetree/bindings/dma/jz4780-dma.txt | 61 ++++++++++++++++++++++
> 1 file changed, 61 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/dma/jz4780-dma.txt
>
> diff --git a/Documentation/devicetree/bindings/dma/jz4780-dma.txt b/Documentation/devicetree/bindings/dma/jz4780-dma.txt
> new file mode 100644
> index 0000000..ce90011
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/jz4780-dma.txt
> @@ -0,0 +1,61 @@
> +* Ingenic JZ4780 DMA Controller
> +
> +Required properties:
> +
> +- compatible: Should be "ingenic,jz4780-dma"
> +- reg: Should contain the DMA controller registers location and length.
> +- interrupts: Should contain the interrupt specifier of the DMA controller.
> +- interrupt-parent: Should be the phandle of the interrupt controller that
> +- clocks: Should contain a clock specifier for the JZ4780 PDMA clock.
> +- #dma-cells: Must be <3>. Number of integer cells in the dmas property of
> + DMA clients (see below).
> +
> +Optional properties:
> +
> +- ingenic,reserved-channels: Bitmask of channels to reserve for devices that
> + need a specific channel. These channels will only be assigned when explicitly
> + requested by a client. The primary use for this is channels 0 and 1, which
> + can be configured to have special behaviour for NAND/BCH when using
> + programmable firmware.
> +
> +Example:
> +
> +dma: dma@13420000 {
> + compatible = "ingenic,jz4780-dma";
> + reg = <0x13420000 0x10000>;
> +
> + interrupt-parent = <&intc>;
> + interrupts = <10>;
> +
> + clocks = <&cgu JZ4780_CLK_PDMA>;
> +
> + #dma-cells = <3>;
> +
> + ingenic,reserved-channels = <0x3>;
> +};
> +
> +DMA clients must use the format described in dma.txt, giving a phandle to the
> +DMA controller plus the following 3 integer cells:
> +
> +1. Transmit request type: The DMA request type for transfers to the device on
> + the allocated channel, as defined in the SoC documentation. If set to 0,
> + transfers to the device will not be allowed on the channel.
> +
> +2. Receive request type: The DMA request type for transfers from the device on
> + the allocated channel, as defined in the SoC documentation. If set to 0,
> + transfers from the device will not be allowed on the channel.
> +
> +3. Channel: If set to 0xffffffff, any available channel will be allocated for
> + the client. Otherwise, the exact channel specified will be used. The channel
> + should be reserved on the DMA controller using the ingenic,reserved-channels
> + property.
Update.
I'm taking a look at these bindings again and see if Transmit/Receive request types 'need' to be separate.
mmc driver is the only one using it like that.
Sorry for the spam.
Regards,
ZubairLK
> +
> +Example:
> +
> +uart0: serial@10030000 {
> + ...
> + dmas = <&dma 0x14 0 0xffffffff
> + &dma 0 0x15 0xffffffff>;
> + dma-names = "tx", "rx";
> + ...
> +};
>