[PATCH V2 1/3] spi: img-spfi: Implement a handle_err() callback

[PATCH V2 1/3] spi: img-spfi: Implement a handle_err() callback

[Andrew Bresticker]

From: Ezequiel Garcia <ezequiel.garcia-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org>

The driver can be greatly simplified by moving the transfer timeout
handling to a handle_err() callback.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Andrew Bresticker <abrestic-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
---
Changes from v1:
 - Moved timeout handling from unprepare_message() to handle_err()
---
 drivers/spi/spi-img-spfi.c | 44 ++++++++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/drivers/spi/spi-img-spfi.c b/drivers/spi/spi-img-spfi.c
index bef986f..a3cf5be 100644
--- a/drivers/spi/spi-img-spfi.c
+++ b/drivers/spi/spi-img-spfi.c
@@ -270,7 +270,6 @@ static int img_spfi_start_pio(struct spi_master *master,
 
 	if (rx_bytes > 0 || tx_bytes > 0) {
 		dev_err(spfi->dev, "PIO transfer timed out\n");
-		spfi_reset(spfi);
 		return -ETIMEDOUT;
 	}
 
@@ -396,6 +395,29 @@ stop_dma:
 	return -EIO;
 }
 
+static void img_spfi_handle_err(struct spi_master *master,
+				struct spi_message *msg)
+{
+	struct img_spfi *spfi = spi_master_get_devdata(master);
+	unsigned long flags;
+
+	/*
+	 * Stop all DMA and reset the controller if the previous transaction
+	 * timed-out and never completed it's DMA.
+	 */
+	spin_lock_irqsave(&spfi->lock, flags);
+	if (spfi->tx_dma_busy || spfi->rx_dma_busy) {
+		spfi->tx_dma_busy = false;
+		spfi->rx_dma_busy = false;
+
+		dmaengine_terminate_all(spfi->tx_ch);
+		dmaengine_terminate_all(spfi->rx_ch);
+	}
+	spin_unlock_irqrestore(&spfi->lock, flags);
+
+	spfi_reset(spfi);
+}
+
 static int img_spfi_prepare(struct spi_master *master, struct spi_message *msg)
 {
 	struct img_spfi *spfi = spi_master_get_devdata(master);
@@ -462,8 +484,6 @@ static int img_spfi_transfer_one(struct spi_master *master,
 				 struct spi_transfer *xfer)
 {
 	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
-	bool dma_reset = false;
-	unsigned long flags;
 	int ret;
 
 	if (xfer->len > SPFI_TRANSACTION_TSIZE_MASK) {
@@ -473,23 +493,6 @@ static int img_spfi_transfer_one(struct spi_master *master,
 		return -EINVAL;
 	}
 
-	/*
-	 * Stop all DMA and reset the controller if the previous transaction
-	 * timed-out and never completed it's DMA.
-	 */
-	spin_lock_irqsave(&spfi->lock, flags);
-	if (spfi->tx_dma_busy || spfi->rx_dma_busy) {
-		dev_err(spfi->dev, "SPI DMA still busy\n");
-		dma_reset = true;
-	}
-	spin_unlock_irqrestore(&spfi->lock, flags);
-
-	if (dma_reset) {
-		dmaengine_terminate_all(spfi->tx_ch);
-		dmaengine_terminate_all(spfi->rx_ch);
-		spfi_reset(spfi);
-	}
-
 	img_spfi_config(master, spi, xfer);
 	if (master->can_dma && master->can_dma(master, spi, xfer))
 		ret = img_spfi_start_dma(master, spi, xfer);
@@ -607,6 +610,7 @@ static int img_spfi_probe(struct platform_device *pdev)
 	master->set_cs = img_spfi_set_cs;
 	master->transfer_one = img_spfi_transfer_one;
 	master->prepare_message = img_spfi_prepare;
+	master->handle_err = img_spfi_handle_err;
 
 	spfi->tx_ch = dma_request_slave_channel(spfi->dev, "tx");
 	spfi->rx_ch = dma_request_slave_channel(spfi->dev, "rx");
-- 
2.2.0.rc0.207.ga3a616c

--
To unsubscribe from this list: send the line "unsubscribe linux-spi" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH V2 2/3] spi: img-spfi: Reset controller after each message

[Andrew Bresticker]

Imagination has recommended that the SPFI controller be reset after
each message, regardless of success or failure.  Do this in an
unprepare_message() callback.

Signed-off-by: Andrew Bresticker <abrestic-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
---
New for v2.
---
 drivers/spi/spi-img-spfi.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-img-spfi.c b/drivers/spi/spi-img-spfi.c
index a3cf5be..dedb7d8 100644
--- a/drivers/spi/spi-img-spfi.c
+++ b/drivers/spi/spi-img-spfi.c
@@ -414,8 +414,6 @@ static void img_spfi_handle_err(struct spi_master *master,
 		dmaengine_terminate_all(spfi->rx_ch);
 	}
 	spin_unlock_irqrestore(&spfi->lock, flags);
-
-	spfi_reset(spfi);
 }
 
 static int img_spfi_prepare(struct spi_master *master, struct spi_message *msg)
@@ -437,6 +435,16 @@ static int img_spfi_prepare(struct spi_master *master, struct spi_message *msg)
 	return 0;
 }
 
+static int img_spfi_unprepare(struct spi_master *master,
+			      struct spi_message *msg)
+{
+	struct img_spfi *spfi = spi_master_get_devdata(master);
+
+	spfi_reset(spfi);
+
+	return 0;
+}
+
 static void img_spfi_config(struct spi_master *master, struct spi_device *spi,
 			    struct spi_transfer *xfer)
 {
@@ -610,6 +618,7 @@ static int img_spfi_probe(struct platform_device *pdev)
 	master->set_cs = img_spfi_set_cs;
 	master->transfer_one = img_spfi_transfer_one;
 	master->prepare_message = img_spfi_prepare;
+	master->unprepare_message = img_spfi_unprepare;
 	master->handle_err = img_spfi_handle_err;
 
 	spfi->tx_ch = dma_request_slave_channel(spfi->dev, "tx");
-- 
2.2.0.rc0.207.ga3a616c

--
To unsubscribe from this list: send the line "unsubscribe linux-spi" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH V2 3/3] spi: img-spfi: Control CS lines with GPIO

[Andrew Bresticker]

From: Ezequiel Garcia <ezequiel.garcia-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org>

When the CONTINUE bit is set, the interrupt status we are polling to
identify if a transaction has finished can be sporadic.  Even though
the transfer has finished, the interrupt status may erroneously
indicate that there is still data in the FIFO.  This behaviour causes
random timeouts in large PIO transfers.

Instead of using the CONTINUE bit to control the CS lines, use the SPI
core's CS GPIO handling.  Also, now that the CONTINUE bit is not being
used, we can poll for the ALLDONE interrupt to indicate transfer
completion.

Signed-off-by: Sifan Naeem <sifan.naeem-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Andrew Bresticker <abrestic-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
---
This breaks device-tree backwards compatibility, but all existing
device-trees using this binding have been updated.

No changes from v1.
---
 .../devicetree/bindings/spi/spi-img-spfi.txt       |  1 +
 drivers/spi/spi-img-spfi.c                         | 92 +++++++++++-----------
 2 files changed, 45 insertions(+), 48 deletions(-)

diff --git a/Documentation/devicetree/bindings/spi/spi-img-spfi.txt b/Documentation/devicetree/bindings/spi/spi-img-spfi.txt
index c7dd50f..e02fbf1 100644
--- a/Documentation/devicetree/bindings/spi/spi-img-spfi.txt
+++ b/Documentation/devicetree/bindings/spi/spi-img-spfi.txt
@@ -14,6 +14,7 @@ Required properties:
 - dma-names: Must include the following entries:
   - rx
   - tx
+- cs-gpios: Must specify the GPIOs used for chipselect lines.
 - #address-cells: Must be 1.
 - #size-cells: Must be 0.
 
diff --git a/drivers/spi/spi-img-spfi.c b/drivers/spi/spi-img-spfi.c
index dedb7d8..788e2b1 100644
--- a/drivers/spi/spi-img-spfi.c
+++ b/drivers/spi/spi-img-spfi.c
@@ -12,6 +12,7 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/dmaengine.h>
+#include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/irq.h>
@@ -122,35 +123,31 @@ static inline void spfi_start(struct img_spfi *spfi)
 	spfi_writel(spfi, val, SPFI_CONTROL);
 }
 
-static inline void spfi_stop(struct img_spfi *spfi)
-{
-	u32 val;
-
-	val = spfi_readl(spfi, SPFI_CONTROL);
-	val &= ~SPFI_CONTROL_SPFI_EN;
-	spfi_writel(spfi, val, SPFI_CONTROL);
-}
-
 static inline void spfi_reset(struct img_spfi *spfi)
 {
 	spfi_writel(spfi, SPFI_CONTROL_SOFT_RESET, SPFI_CONTROL);
 	spfi_writel(spfi, 0, SPFI_CONTROL);
 }
 
-static void spfi_flush_tx_fifo(struct img_spfi *spfi)
+static int spfi_wait_all_done(struct img_spfi *spfi)
 {
-	unsigned long timeout = jiffies + msecs_to_jiffies(10);
+	unsigned long timeout = jiffies + msecs_to_jiffies(50);
 
-	spfi_writel(spfi, SPFI_INTERRUPT_SDE, SPFI_INTERRUPT_CLEAR);
 	while (time_before(jiffies, timeout)) {
-		if (spfi_readl(spfi, SPFI_INTERRUPT_STATUS) &
-		    SPFI_INTERRUPT_SDE)
-			return;
+		u32 status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
+
+		if (status & SPFI_INTERRUPT_ALLDONETRIG) {
+			spfi_writel(spfi, SPFI_INTERRUPT_ALLDONETRIG,
+				    SPFI_INTERRUPT_CLEAR);
+			return 0;
+		}
 		cpu_relax();
 	}
 
-	dev_err(spfi->dev, "Timed out waiting for FIFO to drain\n");
+	dev_err(spfi->dev, "Timed out waiting for transaction to complete\n");
 	spfi_reset(spfi);
+
+	return -ETIMEDOUT;
 }
 
 static unsigned int spfi_pio_write32(struct img_spfi *spfi, const u32 *buf,
@@ -236,6 +233,7 @@ static int img_spfi_start_pio(struct spi_master *master,
 	const void *tx_buf = xfer->tx_buf;
 	void *rx_buf = xfer->rx_buf;
 	unsigned long timeout;
+	int ret;
 
 	if (tx_buf)
 		tx_bytes = xfer->len;
@@ -268,15 +266,15 @@ static int img_spfi_start_pio(struct spi_master *master,
 		cpu_relax();
 	}
 
+	ret = spfi_wait_all_done(spfi);
+	if (ret < 0)
+		return ret;
+
 	if (rx_bytes > 0 || tx_bytes > 0) {
 		dev_err(spfi->dev, "PIO transfer timed out\n");
 		return -ETIMEDOUT;
 	}
 
-	if (tx_buf)
-		spfi_flush_tx_fifo(spfi);
-	spfi_stop(spfi);
-
 	return 0;
 }
 
@@ -285,14 +283,12 @@ static void img_spfi_dma_rx_cb(void *data)
 	struct img_spfi *spfi = data;
 	unsigned long flags;
 
-	spin_lock_irqsave(&spfi->lock, flags);
+	spfi_wait_all_done(spfi);
 
+	spin_lock_irqsave(&spfi->lock, flags);
 	spfi->rx_dma_busy = false;
-	if (!spfi->tx_dma_busy) {
-		spfi_stop(spfi);
+	if (!spfi->tx_dma_busy)
 		spi_finalize_current_transfer(spfi->master);
-	}
-
 	spin_unlock_irqrestore(&spfi->lock, flags);
 }
 
@@ -301,16 +297,12 @@ static void img_spfi_dma_tx_cb(void *data)
 	struct img_spfi *spfi = data;
 	unsigned long flags;
 
-	spfi_flush_tx_fifo(spfi);
+	spfi_wait_all_done(spfi);
 
 	spin_lock_irqsave(&spfi->lock, flags);
-
 	spfi->tx_dma_busy = false;
-	if (!spfi->rx_dma_busy) {
-		spfi_stop(spfi);
+	if (!spfi->rx_dma_busy)
 		spi_finalize_current_transfer(spfi->master);
-	}
-
 	spin_unlock_irqrestore(&spfi->lock, flags);
 }
 
@@ -445,6 +437,25 @@ static int img_spfi_unprepare(struct spi_master *master,
 	return 0;
 }
 
+static int img_spfi_setup(struct spi_device *spi)
+{
+	int ret;
+
+	ret = gpio_request_one(spi->cs_gpio, (spi->mode & SPI_CS_HIGH) ?
+			       GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH,
+			       dev_name(&spi->dev));
+	if (ret)
+		dev_err(&spi->dev, "can't request chipselect gpio %d\n",
+				spi->cs_gpio);
+
+	return ret;
+}
+
+static void img_spfi_cleanup(struct spi_device *spi)
+{
+	gpio_free(spi->cs_gpio);
+}
+
 static void img_spfi_config(struct spi_master *master, struct spi_device *spi,
 			    struct spi_transfer *xfer)
 {
@@ -480,10 +491,6 @@ static void img_spfi_config(struct spi_master *master, struct spi_device *spi,
 	else if (xfer->tx_nbits == SPI_NBITS_QUAD &&
 		 xfer->rx_nbits == SPI_NBITS_QUAD)
 		val |= SPFI_CONTROL_TMODE_QUAD << SPFI_CONTROL_TMODE_SHIFT;
-	val &= ~SPFI_CONTROL_CONTINUE;
-	if (!xfer->cs_change && !list_is_last(&xfer->transfer_list,
-					      &master->cur_msg->transfers))
-		val |= SPFI_CONTROL_CONTINUE;
 	spfi_writel(spfi, val, SPFI_CONTROL);
 }
 
@@ -510,17 +517,6 @@ static int img_spfi_transfer_one(struct spi_master *master,
 	return ret;
 }
 
-static void img_spfi_set_cs(struct spi_device *spi, bool enable)
-{
-	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
-	u32 val;
-
-	val = spfi_readl(spfi, SPFI_PORT_STATE);
-	val &= ~(SPFI_PORT_STATE_DEV_SEL_MASK << SPFI_PORT_STATE_DEV_SEL_SHIFT);
-	val |= spi->chip_select << SPFI_PORT_STATE_DEV_SEL_SHIFT;
-	spfi_writel(spfi, val, SPFI_PORT_STATE);
-}
-
 static bool img_spfi_can_dma(struct spi_master *master, struct spi_device *spi,
 			     struct spi_transfer *xfer)
 {
@@ -609,13 +605,13 @@ static int img_spfi_probe(struct platform_device *pdev)
 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_TX_DUAL | SPI_RX_DUAL;
 	if (of_property_read_bool(spfi->dev->of_node, "img,supports-quad-mode"))
 		master->mode_bits |= SPI_TX_QUAD | SPI_RX_QUAD;
-	master->num_chipselect = 5;
 	master->dev.of_node = pdev->dev.of_node;
 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(8);
 	master->max_speed_hz = clk_get_rate(spfi->spfi_clk) / 4;
 	master->min_speed_hz = clk_get_rate(spfi->spfi_clk) / 512;
 
-	master->set_cs = img_spfi_set_cs;
+	master->setup = img_spfi_setup;
+	master->cleanup = img_spfi_cleanup;
 	master->transfer_one = img_spfi_transfer_one;
 	master->prepare_message = img_spfi_prepare;
 	master->unprepare_message = img_spfi_unprepare;
-- 
2.2.0.rc0.207.ga3a616c

--
To unsubscribe from this list: send the line "unsubscribe linux-spi" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V2 1/3] spi: img-spfi: Implement a handle_err() callback

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 290 bytes --]

On Wed, Apr 08, 2015 at 10:03:14AM -0700, Andrew Bresticker wrote:
> From: Ezequiel Garcia <ezequiel.garcia-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org>
> 
> The driver can be greatly simplified by moving the transfer timeout
> handling to a handle_err() callback.

Applied all, thanks.

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 473 bytes --]