The following patchset provides corrections for PIO-mode
and support for DMA transfers in sun6i SPI driver.
Sergey Suloev (6):
spi: sun6i: coding style/readability improvements
spi: sun6i: handle chip select polarity flag
spi: sun6i: restrict transfer length in PIO-mode
spi: sun6i: use completion provided by SPI core
spi: sun6i: introduce register set/unset helpers
spi: sun6i: add DMA transfers support
drivers/spi/spi-sun6i.c | 501 ++++++++++++++++++++++++++++++++++++------------
1 file changed, 378 insertions(+), 123 deletions(-)
--
2.16.2
DMA transfers are now available for sun6i and sun8i SoCs.
The DMA mode is used automatically as soon as requested
transfer length is more than FIFO length.
Signed-off-by: Sergey Suloev <[email protected]>
---
drivers/spi/spi-sun6i.c | 296 ++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 275 insertions(+), 21 deletions(-)
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index a6e6812..e74fa3d 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -14,6 +14,8 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
@@ -55,11 +57,14 @@
#define SUN6I_FIFO_CTL_REG 0x18
#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_MASK 0xff
-#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS 0
+#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_POS 0
+#define SUN6I_FIFO_CTL_RF_DRQ_EN BIT(8)
#define SUN6I_FIFO_CTL_RF_RST BIT(15)
#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_MASK 0xff
-#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS 16
+#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_POS 16
+#define SUN6I_FIFO_CTL_TF_DRQ_EN BIT(24)
#define SUN6I_FIFO_CTL_TF_RST BIT(31)
+#define SUN6I_FIFO_CTL_DMA_DEDICATE BIT(9)|BIT(25)
#define SUN6I_FIFO_STA_REG 0x1c
#define SUN6I_FIFO_STA_RF_CNT_MASK 0x7f
@@ -177,6 +182,15 @@ static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi, int len)
}
}
+static bool sun6i_spi_can_dma(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *tfr)
+{
+ struct sun6i_spi *sspi = spi_master_get_devdata(master);
+
+ return tfr->len > sspi->fifo_depth;
+}
+
static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
{
struct sun6i_spi *sspi = spi_master_get_devdata(spi->master);
@@ -208,6 +222,9 @@ static size_t sun6i_spi_max_transfer_size(struct spi_device *spi)
struct spi_master *master = spi->master;
struct sun6i_spi *sspi = spi_master_get_devdata(master);
+ if (master->can_dma)
+ return SUN6I_MAX_XFER_SIZE;
+
return sspi->fifo_depth;
}
@@ -277,15 +294,174 @@ static int sun6i_spi_wait_for_transfer(struct spi_device *spi,
return 0;
}
+static void sun6i_spi_dma_callback(void *param)
+{
+ struct spi_master *master = param;
+
+ dev_dbg(&master->dev, "DMA transfer complete\n");
+ spi_finalize_current_transfer(master);
+}
+
+static int sun6i_spi_dmap_prep_tx(struct spi_master *master,
+ struct spi_transfer *tfr,
+ dma_cookie_t *cookie)
+{
+ struct dma_async_tx_descriptor *chan_desc = NULL;
+
+ chan_desc = dmaengine_prep_slave_sg(master->dma_tx,
+ tfr->tx_sg.sgl, tfr->tx_sg.nents,
+ DMA_TO_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!chan_desc) {
+ dev_err(&master->dev,
+ "Couldn't prepare TX DMA slave\n");
+ return -EIO;
+ }
+
+ chan_desc->callback = sun6i_spi_dma_callback;
+ chan_desc->callback_param = master;
+
+ *cookie = dmaengine_submit(chan_desc);
+ dma_async_issue_pending(master->dma_tx);
+
+ return 0;
+}
+
+static int sun6i_spi_dmap_prep_rx(struct spi_master *master,
+ struct spi_transfer *tfr,
+ dma_cookie_t *cookie)
+{
+ struct dma_async_tx_descriptor *chan_desc = NULL;
+
+ chan_desc = dmaengine_prep_slave_sg(master->dma_rx,
+ tfr->rx_sg.sgl, tfr->rx_sg.nents,
+ DMA_FROM_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!chan_desc) {
+ dev_err(&master->dev,
+ "Couldn't prepare RX DMA slave\n");
+ return -EIO;
+ }
+
+ chan_desc->callback = sun6i_spi_dma_callback;
+ chan_desc->callback_param = master;
+
+ *cookie = dmaengine_submit(chan_desc);
+ dma_async_issue_pending(master->dma_rx);
+
+ return 0;
+}
+
+static int sun6i_spi_transfer_one_dma(struct spi_device *spi,
+ struct spi_transfer *tfr)
+{
+ struct spi_master *master = spi->master;
+ struct sun6i_spi *sspi = spi_master_get_devdata(master);
+ dma_cookie_t tx_cookie = 0,rx_cookie = 0;
+ enum dma_status status;
+ int ret;
+ u32 reg, trig_level = 0;
+
+ dev_dbg(&master->dev, "Using DMA mode for transfer\n");
+
+ reg = sun6i_spi_read(sspi, SUN6I_FIFO_CTL_REG);
+
+ if (sspi->tx_buf) {
+ ret = sun6i_spi_dmap_prep_tx(master, tfr, &tx_cookie);
+ if (ret)
+ goto out;
+
+ reg |= SUN6I_FIFO_CTL_TF_DRQ_EN;
+
+ trig_level = sspi->fifo_depth;
+ reg &= ~SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_MASK;
+ reg |= (trig_level << SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_POS);
+ }
+
+ if (sspi->rx_buf) {
+ ret = sun6i_spi_dmap_prep_rx(master, tfr, &rx_cookie);
+ if (ret)
+ goto out;
+
+ reg |= SUN6I_FIFO_CTL_RF_DRQ_EN;
+
+ trig_level = 1;
+ reg &= ~SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_MASK;
+ reg |= (trig_level << SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_POS);
+ }
+
+ /* Enable Dedicated DMA requests */
+ sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG,
+ reg | SUN6I_FIFO_CTL_DMA_DEDICATE);
+
+ /* Start transfer */
+ sun6i_spi_set(sspi, SUN6I_TFR_CTL_REG, SUN6I_TFR_CTL_XCH);
+
+ ret = sun6i_spi_wait_for_transfer(spi, tfr);
+ if (ret)
+ goto out;
+
+ if (sspi->tx_buf && (status = dma_async_is_tx_complete(master->dma_tx,
+ tx_cookie, NULL, NULL))) {
+ dev_warn(&master->dev,
+ "DMA returned completion status of: %s\n",
+ status == DMA_ERROR ? "error" : "in progress");
+ }
+ if (sspi->rx_buf && (status = dma_async_is_tx_complete(master->dma_rx,
+ rx_cookie, NULL, NULL))) {
+ dev_warn(&master->dev,
+ "DMA returned completion status of: %s\n",
+ status == DMA_ERROR ? "error" : "in progress");
+ }
+
+out:
+ if (ret) {
+ dev_dbg(&master->dev, "DMA channel teardown\n");
+ if (sspi->tx_buf)
+ dmaengine_terminate_sync(master->dma_tx);
+ if (sspi->rx_buf)
+ dmaengine_terminate_sync(master->dma_rx);
+ }
+
+ sun6i_spi_drain_fifo(sspi, sspi->fifo_depth);
+
+ sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
+
+ return ret;
+}
+
+static int sun6i_spi_transfer_one_pio(struct spi_device *spi,
+ struct spi_transfer *tfr)
+{
+ struct spi_master *master = spi->master;
+ struct sun6i_spi *sspi = spi_master_get_devdata(master);
+ int ret;
+
+ /* Disable DMA requests */
+ sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG, 0);
+
+ sun6i_spi_fill_fifo(sspi, sspi->fifo_depth);
+
+ /* Enable transfer complete IRQ */
+ sun6i_spi_set(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC);
+
+ /* Start transfer */
+ sun6i_spi_set(sspi, SUN6I_TFR_CTL_REG, SUN6I_TFR_CTL_XCH);
+
+ ret = sun6i_spi_wait_for_transfer(spi, tfr);
+
+ sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
+
+ return ret;
+}
+
static int sun6i_spi_transfer_one(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *tfr)
{
struct sun6i_spi *sspi = spi_master_get_devdata(master);
- unsigned int mclk_rate, div, timeout;
- unsigned int start, end, tx_time;
+ unsigned int mclk_rate, div;
unsigned int tx_len = 0;
- int ret = 0;
u32 reg;
/* A zero length transfer never finishes if programmed
@@ -293,10 +469,15 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
if (!tfr->len)
return 0;
- /* Don't support transfer larger than the FIFO */
- if (tfr->len > sspi->fifo_depth)
+ if (tfr->len > SUN6I_MAX_XFER_SIZE)
return -EMSGSIZE;
+ if (!master->can_dma) {
+ /* Don't support transfer larger than the FIFO */
+ if (tfr->len > sspi->fifo_depth)
+ return -EMSGSIZE;
+ }
+
sspi->tx_buf = tfr->tx_buf;
sspi->rx_buf = tfr->rx_buf;
sspi->len = tfr->len;
@@ -353,21 +534,10 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG,
SUN6I_BURST_CTL_CNT_STC(tx_len));
- /* Fill the TX FIFO */
- sun6i_spi_fill_fifo(sspi, sspi->fifo_depth);
-
- /* Enable transfer complete interrupt */
- sun6i_spi_set(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC);
-
- /* Start the transfer */
- sun6i_spi_set(sspi, SUN6I_TFR_CTL_REG, SUN6I_TFR_CTL_XCH);
-
- /* Wait for completion */
- ret = sun6i_spi_wait_for_transfer(spi, tfr);
-
- sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
+ if (sun6i_spi_can_dma(master, spi, tfr))
+ return sun6i_spi_transfer_one_dma(spi, tfr);
- return ret;
+ return sun6i_spi_transfer_one_pio(spi, tfr);
}
static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
@@ -389,6 +559,76 @@ static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
return IRQ_NONE;
}
+static int sun6i_spi_dma_setup(struct platform_device *pdev,
+ struct resource *res)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct dma_slave_config dma_sconf;
+ int ret;
+
+ master->dma_tx = dma_request_slave_channel_reason(&pdev->dev, "tx");
+ if (IS_ERR(master->dma_tx)) {
+ dev_err(&pdev->dev, "Unable to acquire DMA TX channel\n");
+ ret = PTR_ERR(master->dma_tx);
+ goto out;
+ }
+
+ dma_sconf.direction = DMA_MEM_TO_DEV;
+ dma_sconf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconf.dst_addr = res->start + SUN6I_TXDATA_REG;
+ dma_sconf.src_maxburst = 1;
+ dma_sconf.dst_maxburst = 1;
+
+ ret = dmaengine_slave_config(master->dma_tx, &dma_sconf);
+ if (ret) {
+ dev_err(&pdev->dev, "Unable to configure DMA TX slave\n");
+ goto err_rel_tx;
+ }
+
+ master->dma_rx = dma_request_slave_channel_reason(&pdev->dev, "rx");
+ if (IS_ERR(master->dma_rx)) {
+ dev_err(&pdev->dev, "Unable to acquire DMA RX channel\n");
+ ret = PTR_ERR(master->dma_rx);
+ goto err_rel_tx;
+ }
+
+ dma_sconf.direction = DMA_DEV_TO_MEM;
+ dma_sconf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconf.src_addr = res->start + SUN6I_RXDATA_REG;
+ dma_sconf.src_maxburst = 1;
+ dma_sconf.dst_maxburst = 1;
+
+ ret = dmaengine_slave_config(master->dma_rx, &dma_sconf);
+ if (ret) {
+ dev_err(&pdev->dev, "Unable to configure DMA RX slave\n");
+ goto err_rel_rx;
+ }
+
+ /* don't set can_dma unless both channels are valid*/
+ master->can_dma = sun6i_spi_can_dma;
+
+ return 0;
+
+err_rel_rx:
+ dma_release_channel(master->dma_rx);
+err_rel_tx:
+ dma_release_channel(master->dma_tx);
+out:
+ master->dma_tx = NULL;
+ master->dma_rx = NULL;
+ return ret;
+}
+
+static void sun6i_spi_dma_release(struct spi_master *master)
+{
+ if (master->can_dma) {
+ dma_release_channel(master->dma_rx);
+ dma_release_channel(master->dma_tx);
+ }
+}
+
static int sun6i_spi_runtime_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
@@ -510,6 +750,15 @@ static int sun6i_spi_probe(struct platform_device *pdev)
goto err_free_master;
}
+ ret = sun6i_spi_dma_setup(pdev, res);
+ if (ret) {
+ if (ret == -EPROBE_DEFER) {
+ /* wait for the dma driver to load */
+ goto err_free_master;
+ }
+ dev_warn(&pdev->dev, "DMA transfer not supported\n");
+ }
+
/*
* This wake-up/shutdown pattern is to be able to have the
* device woken up, even if runtime_pm is disabled
@@ -536,14 +785,19 @@ err_pm_disable:
pm_runtime_disable(&pdev->dev);
sun6i_spi_runtime_suspend(&pdev->dev);
err_free_master:
+ sun6i_spi_dma_release(master);
spi_master_put(master);
return ret;
}
static int sun6i_spi_remove(struct platform_device *pdev)
{
+ struct spi_master *master = platform_get_drvdata(pdev);
+
pm_runtime_force_suspend(&pdev->dev);
+ sun6i_spi_dma_release(master);
+
return 0;
}
--
2.16.2
Minor changes to fulfill the coding style and
improve the readability.
Signed-off-by: Sergey Suloev <[email protected]>
---
drivers/spi/spi-sun6i.c | 115 +++++++++++++++++++++++++++---------------------
1 file changed, 65 insertions(+), 50 deletions(-)
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 8533f4e..ff790dc 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -88,8 +88,12 @@
#define SUN6I_TXDATA_REG 0x200
#define SUN6I_RXDATA_REG 0x300
+#define SUN6I_SPI_MODE_BITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
+
+#define SUN6I_SPI_MAX_SPEED_HZ 100000000
+#define SUN6I_SPI_MIN_SPEED_HZ 3000
+
struct sun6i_spi {
- struct spi_master *master;
void __iomem *base_addr;
struct clk *hclk;
struct clk *mclk;
@@ -189,6 +193,9 @@ static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
else
reg &= ~SUN6I_TFR_CTL_CS_LEVEL;
+ /* We want to control the chip select manually */
+ reg |= SUN6I_TFR_CTL_CS_MANUAL;
+
sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
}
@@ -197,6 +204,48 @@ static size_t sun6i_spi_max_transfer_size(struct spi_device *spi)
return SUN6I_MAX_XFER_SIZE - 1;
}
+static int sun6i_spi_prepare_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct spi_device *spi = msg->spi;
+ struct sun6i_spi *sspi = spi_master_get_devdata(master);
+ u32 reg;
+
+ /*
+ * Setup the transfer control register: Chip Select,
+ * polarities, etc.
+ */
+ reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
+
+ if (spi->mode & SPI_CPOL)
+ reg |= SUN6I_TFR_CTL_CPOL;
+ else
+ reg &= ~SUN6I_TFR_CTL_CPOL;
+
+ if (spi->mode & SPI_CPHA)
+ reg |= SUN6I_TFR_CTL_CPHA;
+ else
+ reg &= ~SUN6I_TFR_CTL_CPHA;
+
+ if (spi->mode & SPI_LSB_FIRST)
+ reg |= SUN6I_TFR_CTL_FBS;
+ else
+ reg &= ~SUN6I_TFR_CTL_FBS;
+
+ /*
+ * If it's a TX only transfer, we don't want to fill the RX
+ * FIFO with bogus data
+ */
+ if (sspi->rx_buf)
+ reg &= ~SUN6I_TFR_CTL_DHB;
+ else
+ reg |= SUN6I_TFR_CTL_DHB;
+
+ sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
+
+ return 0;
+}
+
static int sun6i_spi_transfer_one(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *tfr)
@@ -235,40 +284,6 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
(trig_level << SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS) |
(trig_level << SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS));
- /*
- * Setup the transfer control register: Chip Select,
- * polarities, etc.
- */
- reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
-
- if (spi->mode & SPI_CPOL)
- reg |= SUN6I_TFR_CTL_CPOL;
- else
- reg &= ~SUN6I_TFR_CTL_CPOL;
-
- if (spi->mode & SPI_CPHA)
- reg |= SUN6I_TFR_CTL_CPHA;
- else
- reg &= ~SUN6I_TFR_CTL_CPHA;
-
- if (spi->mode & SPI_LSB_FIRST)
- reg |= SUN6I_TFR_CTL_FBS;
- else
- reg &= ~SUN6I_TFR_CTL_FBS;
-
- /*
- * If it's a TX only transfer, we don't want to fill the RX
- * FIFO with bogus data
- */
- if (sspi->rx_buf)
- reg &= ~SUN6I_TFR_CTL_DHB;
- else
- reg |= SUN6I_TFR_CTL_DHB;
-
- /* We want to control the chip select manually */
- reg |= SUN6I_TFR_CTL_CS_MANUAL;
-
- sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
/* Ensure that we have a parent clock fast enough */
mclk_rate = clk_get_rate(sspi->mclk);
@@ -442,12 +457,24 @@ static int sun6i_spi_probe(struct platform_device *pdev)
struct resource *res;
int ret = 0, irq;
- master = spi_alloc_master(&pdev->dev, sizeof(struct sun6i_spi));
+ master = spi_alloc_master(&pdev->dev, sizeof(*sspi));
if (!master) {
dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
return -ENOMEM;
}
+ master->max_speed_hz = SUN6I_SPI_MAX_SPEED_HZ;
+ master->min_speed_hz = SUN6I_SPI_MIN_SPEED_HZ;
+ master->num_chipselect = 4;
+ master->mode_bits = SUN6I_SPI_MODE_BITS;
+ master->bits_per_word_mask = SPI_BPW_MASK(8);
+ master->set_cs = sun6i_spi_set_cs;
+ master->prepare_message = sun6i_spi_prepare_message;
+ master->transfer_one = sun6i_spi_transfer_one;
+ master->max_transfer_size = sun6i_spi_max_transfer_size;
+ master->dev.of_node = pdev->dev.of_node;
+ master->auto_runtime_pm = true;
+
platform_set_drvdata(pdev, master);
sspi = spi_master_get_devdata(master);
@@ -466,26 +493,14 @@ static int sun6i_spi_probe(struct platform_device *pdev)
}
ret = devm_request_irq(&pdev->dev, irq, sun6i_spi_handler,
- 0, "sun6i-spi", sspi);
+ 0, dev_name(&pdev->dev), sspi);
if (ret) {
dev_err(&pdev->dev, "Cannot request IRQ\n");
goto err_free_master;
}
- sspi->master = master;
sspi->fifo_depth = (unsigned long)of_device_get_match_data(&pdev->dev);
- master->max_speed_hz = 100 * 1000 * 1000;
- master->min_speed_hz = 3 * 1000;
- master->set_cs = sun6i_spi_set_cs;
- master->transfer_one = sun6i_spi_transfer_one;
- master->num_chipselect = 4;
- master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
- master->bits_per_word_mask = SPI_BPW_MASK(8);
- master->dev.of_node = pdev->dev.of_node;
- master->auto_runtime_pm = true;
- master->max_transfer_size = sun6i_spi_max_transfer_size;
-
sspi->hclk = devm_clk_get(&pdev->dev, "ahb");
if (IS_ERR(sspi->hclk)) {
dev_err(&pdev->dev, "Unable to acquire AHB clock\n");
@@ -525,7 +540,7 @@ static int sun6i_spi_probe(struct platform_device *pdev)
ret = devm_spi_register_master(&pdev->dev, master);
if (ret) {
- dev_err(&pdev->dev, "cannot register SPI master\n");
+ dev_err(&pdev->dev, "Couldn't register SPI master\n");
goto err_pm_disable;
}
--
2.16.2
There is no need to handle 3/4 empty/full interrupts as
the maximum supported transfer length in PIO mode is
128 bytes for sun6i- and 64 bytes for sun8i-family SoCs.
Signed-off-by: Sergey Suloev <[email protected]>
---
drivers/spi/spi-sun6i.c | 61 ++++++++++++++-----------------------------------
1 file changed, 17 insertions(+), 44 deletions(-)
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index f992a7d..13396bd 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -207,7 +207,10 @@ static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
static size_t sun6i_spi_max_transfer_size(struct spi_device *spi)
{
- return SUN6I_MAX_XFER_SIZE - 1;
+ struct spi_master *master = spi->master;
+ struct sun6i_spi *sspi = spi_master_get_devdata(master);
+
+ return sspi->fifo_depth;
}
static int sun6i_spi_prepare_message(struct spi_master *master,
@@ -259,13 +262,18 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
struct sun6i_spi *sspi = spi_master_get_devdata(master);
unsigned int mclk_rate, div, timeout;
unsigned int start, end, tx_time;
- unsigned int trig_level;
unsigned int tx_len = 0;
int ret = 0;
u32 reg;
- if (tfr->len > SUN6I_MAX_XFER_SIZE)
- return -EINVAL;
+ /* A zero length transfer never finishes if programmed
+ in the hardware */
+ if (!tfr->len)
+ return 0;
+
+ /* Don't support transfer larger than the FIFO */
+ if (tfr->len > sspi->fifo_depth)
+ return -EMSGSIZE;
reinit_completion(&sspi->done);
sspi->tx_buf = tfr->tx_buf;
@@ -279,17 +287,6 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG,
SUN6I_FIFO_CTL_RF_RST | SUN6I_FIFO_CTL_TF_RST);
- /*
- * Setup FIFO interrupt trigger level
- * Here we choose 3/4 of the full fifo depth, as it's the hardcoded
- * value used in old generation of Allwinner SPI controller.
- * (See spi-sun4i.c)
- */
- trig_level = sspi->fifo_depth / 4 * 3;
- sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG,
- (trig_level << SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS) |
- (trig_level << SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS));
-
/* Ensure that we have a parent clock fast enough */
mclk_rate = clk_get_rate(sspi->mclk);
@@ -338,12 +335,8 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
/* Fill the TX FIFO */
sun6i_spi_fill_fifo(sspi, sspi->fifo_depth);
- /* Enable the interrupts */
- sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC);
- sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TC |
- SUN6I_INT_CTL_RF_RDY);
- if (tx_len > sspi->fifo_depth)
- sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ);
+ /* Enable transfer complete interrupt */
+ sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TC);
/* Start the transfer */
reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
@@ -372,7 +365,9 @@ out:
static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
{
struct sun6i_spi *sspi = dev_id;
- u32 status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG);
+ u32 status;
+
+ status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG);
/* Transfer complete */
if (status & SUN6I_INT_CTL_TC) {
@@ -382,28 +377,6 @@ static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}
- /* Receive FIFO 3/4 full */
- if (status & SUN6I_INT_CTL_RF_RDY) {
- sun6i_spi_drain_fifo(sspi, SUN6I_FIFO_DEPTH);
- /* Only clear the interrupt _after_ draining the FIFO */
- sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_RF_RDY);
- return IRQ_HANDLED;
- }
-
- /* Transmit FIFO 3/4 empty */
- if (status & SUN6I_INT_CTL_TF_ERQ) {
- sun6i_spi_fill_fifo(sspi, SUN6I_FIFO_DEPTH);
-
- if (!sspi->len)
- /* nothing left to transmit */
- sun6i_spi_disable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ);
-
- /* Only clear the interrupt _after_ re-seeding the FIFO */
- sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TF_ERQ);
-
- return IRQ_HANDLED;
- }
-
return IRQ_NONE;
}
--
2.16.2
As long as the completion is already provided by the SPI core
then there is no need to waste extra-memory on this.
Also a waiting function was added to avoid code duplication.
Signed-off-by: Sergey Suloev <[email protected]>
---
drivers/spi/spi-sun6i.c | 50 ++++++++++++++++++++++++++++---------------------
1 file changed, 29 insertions(+), 21 deletions(-)
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 13396bd..fc43752 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -99,8 +99,6 @@ struct sun6i_spi {
struct clk *mclk;
struct reset_control *rstc;
- struct completion done;
-
const u8 *tx_buf;
u8 *rx_buf;
int len;
@@ -255,6 +253,30 @@ static int sun6i_spi_prepare_message(struct spi_master *master,
return 0;
}
+static int sun6i_spi_wait_for_transfer(struct spi_device *spi,
+ struct spi_transfer *tfr)
+{
+ struct spi_master *master = spi->master;
+ unsigned int start, end, tx_time;
+ unsigned int timeout;
+
+ /* smart wait for completion */
+ tx_time = max(tfr->len * 8 * 2 / (tfr->speed_hz / 1000), 100U);
+ start = jiffies;
+ timeout = wait_for_completion_timeout(&master->xfer_completion,
+ msecs_to_jiffies(tx_time));
+ end = jiffies;
+ if (!timeout) {
+ dev_warn(&master->dev,
+ "%s: timeout transferring %u bytes@%iHz for %i(%i)ms",
+ dev_name(&spi->dev), tfr->len, tfr->speed_hz,
+ jiffies_to_msecs(end - start), tx_time);
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
static int sun6i_spi_transfer_one(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *tfr)
@@ -275,7 +297,6 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
if (tfr->len > sspi->fifo_depth)
return -EMSGSIZE;
- reinit_completion(&sspi->done);
sspi->tx_buf = tfr->tx_buf;
sspi->rx_buf = tfr->rx_buf;
sspi->len = tfr->len;
@@ -342,21 +363,9 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg | SUN6I_TFR_CTL_XCH);
- tx_time = max(tfr->len * 8 * 2 / (tfr->speed_hz / 1000), 100U);
- start = jiffies;
- timeout = wait_for_completion_timeout(&sspi->done,
- msecs_to_jiffies(tx_time));
- end = jiffies;
- if (!timeout) {
- dev_warn(&master->dev,
- "%s: timeout transferring %u bytes@%iHz for %i(%i)ms",
- dev_name(&spi->dev), tfr->len, tfr->speed_hz,
- jiffies_to_msecs(end - start), tx_time);
- ret = -ETIMEDOUT;
- goto out;
- }
+ /* Wait for completion */
+ ret = sun6i_spi_wait_for_transfer(spi, tfr);
-out:
sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
return ret;
@@ -364,7 +373,8 @@ out:
static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
{
- struct sun6i_spi *sspi = dev_id;
+ struct spi_master *master = dev_id;
+ struct sun6i_spi *sspi = spi_master_get_devdata(master);
u32 status;
status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG);
@@ -373,7 +383,7 @@ static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
if (status & SUN6I_INT_CTL_TC) {
sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TC);
sun6i_spi_drain_fifo(sspi, sspi->fifo_depth);
- complete(&sspi->done);
+ spi_finalize_current_transfer(master);
return IRQ_HANDLED;
}
@@ -494,8 +504,6 @@ static int sun6i_spi_probe(struct platform_device *pdev)
goto err_free_master;
}
- init_completion(&sspi->done);
-
sspi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
if (IS_ERR(sspi->rstc)) {
dev_err(&pdev->dev, "Couldn't get reset controller\n");
--
2.16.2
Two helper functions were added in order to update
registers easily.
Signed-off-by: Sergey Suloev <[email protected]>
---
drivers/spi/spi-sun6i.c | 31 +++++++++++++++----------------
1 file changed, 15 insertions(+), 16 deletions(-)
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index fc43752..a6e6812 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -115,29 +115,29 @@ static inline void sun6i_spi_write(struct sun6i_spi *sspi, u32 reg, u32 value)
writel(value, sspi->base_addr + reg);
}
-static inline u32 sun6i_spi_get_tx_fifo_count(struct sun6i_spi *sspi)
+static inline void sun6i_spi_set(struct sun6i_spi *sspi, u32 addr, u32 val)
{
- u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
-
- reg >>= SUN6I_FIFO_STA_TF_CNT_BITS;
+ u32 reg = sun6i_spi_read(sspi, addr);
- return reg & SUN6I_FIFO_STA_TF_CNT_MASK;
+ reg |= val;
+ sun6i_spi_write(sspi, addr, reg);
}
-static inline void sun6i_spi_enable_interrupt(struct sun6i_spi *sspi, u32 mask)
+static inline void sun6i_spi_unset(struct sun6i_spi *sspi, u32 addr, u32 val)
{
- u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG);
+ u32 reg = sun6i_spi_read(sspi, addr);
- reg |= mask;
- sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
+ reg &= ~val;
+ sun6i_spi_write(sspi, addr, reg);
}
-static inline void sun6i_spi_disable_interrupt(struct sun6i_spi *sspi, u32 mask)
+static inline u32 sun6i_spi_get_tx_fifo_count(struct sun6i_spi *sspi)
{
- u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG);
+ u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
+
+ reg >>= SUN6I_FIFO_STA_TF_CNT_BITS;
- reg &= ~mask;
- sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
+ return reg & SUN6I_FIFO_STA_TF_CNT_MASK;
}
static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi, int len)
@@ -357,11 +357,10 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
sun6i_spi_fill_fifo(sspi, sspi->fifo_depth);
/* Enable transfer complete interrupt */
- sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TC);
+ sun6i_spi_set(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC);
/* Start the transfer */
- reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
- sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg | SUN6I_TFR_CTL_XCH);
+ sun6i_spi_set(sspi, SUN6I_TFR_CTL_REG, SUN6I_TFR_CTL_XCH);
/* Wait for completion */
ret = sun6i_spi_wait_for_transfer(spi, tfr);
--
2.16.2
The chip select polarity flag is declared as supported
but is not handled in the code.
Signed-off-by: Sergey Suloev <[email protected]>
---
drivers/spi/spi-sun6i.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index ff790dc..f992a7d 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -193,6 +193,12 @@ static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
else
reg &= ~SUN6I_TFR_CTL_CS_LEVEL;
+ /* Handle chip select "reverse" polarity */
+ if (spi->mode & SPI_CS_HIGH)
+ reg &= ~SUN6I_TFR_CTL_SPOL;
+ else
+ reg |= SUN6I_TFR_CTL_SPOL;
+
/* We want to control the chip select manually */
reg |= SUN6I_TFR_CTL_CS_MANUAL;
--
2.16.2
On Fri, Mar 30, 2018 at 3:22 PM, Sergey Suloev <[email protected]> wrote:
> The following patchset provides corrections for PIO-mode
> and support for DMA transfers in sun6i SPI driver.
Is this the same series you sent 12 hours ago? What's different?
Please version your patch series and provide a changelog.
ChenYu
> Sergey Suloev (6):
> spi: sun6i: coding style/readability improvements
> spi: sun6i: handle chip select polarity flag
> spi: sun6i: restrict transfer length in PIO-mode
> spi: sun6i: use completion provided by SPI core
> spi: sun6i: introduce register set/unset helpers
> spi: sun6i: add DMA transfers support
>
> drivers/spi/spi-sun6i.c | 501 ++++++++++++++++++++++++++++++++++++------------
> 1 file changed, 378 insertions(+), 123 deletions(-)
>
> --
> 2.16.2
>