[PATCH linux-next v4 0/4] i.MX ECSPI controller slave mode support

[PATCH linux-next v4 0/4] i.MX ECSPI controller slave mode support

[Jiada Wang]

Changes in v4:
* rebased to head of linux-next to resolve conflict
* optimized mx53_ecspi_rx_slave()

Changes in v3:
* renamed several variables for for better readability
* created spi_imx_pio_transfer_slave() for slave pio transfer
* added fifo_size, has_dmamode and has_slavemode in spi_imx_devtype_data

Changes in v2:
* re-workd i.MX ECSPI controller slave mode support based on Geert's work

Jiada Wang (4):
  spi: imx: introduce fifo_size and has_dmamode in spi_imx_devtype_data
  spi: imx: add selection for iMX53 and iMX6 controller
  ARM: dts: imx: change compatibility for SPI controllers on imx53 later
    soc
  spi: imx: Add support for SPI Slave mode

 .../devicetree/bindings/spi/fsl-imx-cspi.txt       |   1 +
 arch/arm/boot/dts/imx53.dtsi                       |   4 +-
 arch/arm/boot/dts/imx6q.dtsi                       |   2 +-
 arch/arm/boot/dts/imx6qdl.dtsi                     |   8 +-
 arch/arm/boot/dts/imx6sl.dtsi                      |   8 +-
 arch/arm/boot/dts/imx6sx.dtsi                      |   8 +-
 arch/arm/boot/dts/imx6ul.dtsi                      |   8 +-
 drivers/spi/spi-imx.c                              | 273 ++++++++++++++++++---
 8 files changed, 255 insertions(+), 57 deletions(-)

-- 
2.9.3

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[PATCH linux-next v4 1/4] spi: imx: introduce fifo_size and has_dmamode in spi_imx_devtype_data

[Jiada Wang]

Different ECSPI controller has different fifosize and DMA capability,
instead of calling functions to identify these information by check
devtype. add fifo_size and has_dmamode to spi_imx_devtype_data.
so that these information can be directly accessed.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 drivers/spi/spi-imx.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index e544f45..4469121 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -74,6 +74,8 @@ struct spi_imx_devtype_data {
 	void (*trigger)(struct spi_imx_data *);
 	int (*rx_available)(struct spi_imx_data *);
 	void (*reset)(struct spi_imx_data *);
+	bool has_dmamode;
+	unsigned int fifo_size;
 	enum spi_imx_devtype devtype;
 };
 
@@ -125,11 +127,6 @@ static inline int is_imx51_ecspi(struct spi_imx_data *d)
 	return d->devtype_data->devtype == IMX51_ECSPI;
 }
 
-static inline unsigned spi_imx_get_fifosize(struct spi_imx_data *d)
-{
-	return is_imx51_ecspi(d) ? 64 : 8;
-}
-
 #define MXC_SPI_BUF_RX(type)						\
 static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx)		\
 {									\
@@ -219,7 +216,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 	if (bytes_per_word != 1 && bytes_per_word != 2 && bytes_per_word != 4)
 		return false;
 
-	for (i = spi_imx_get_fifosize(spi_imx) / 2; i > 0; i--) {
+	for (i = spi_imx->devtype_data->fifo_size / 2; i > 0; i--) {
 		if (!(transfer->len % (i * bytes_per_word)))
 			break;
 	}
@@ -693,6 +690,8 @@ static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
 	.trigger = mx1_trigger,
 	.rx_available = mx1_rx_available,
 	.reset = mx1_reset,
+	.fifo_size = 8,
+	.has_dmamode = false,
 	.devtype = IMX1_CSPI,
 };
 
@@ -702,6 +701,8 @@ static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
 	.trigger = mx21_trigger,
 	.rx_available = mx21_rx_available,
 	.reset = mx21_reset,
+	.fifo_size = 8,
+	.has_dmamode = false,
 	.devtype = IMX21_CSPI,
 };
 
@@ -712,6 +713,8 @@ static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
 	.trigger = mx21_trigger,
 	.rx_available = mx21_rx_available,
 	.reset = mx21_reset,
+	.fifo_size = 8,
+	.has_dmamode = false,
 	.devtype = IMX27_CSPI,
 };
 
@@ -721,6 +724,8 @@ static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
 	.trigger = mx31_trigger,
 	.rx_available = mx31_rx_available,
 	.reset = mx31_reset,
+	.fifo_size = 8,
+	.has_dmamode = false,
 	.devtype = IMX31_CSPI,
 };
 
@@ -731,6 +736,8 @@ static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
 	.trigger = mx31_trigger,
 	.rx_available = mx31_rx_available,
 	.reset = mx31_reset,
+	.fifo_size = 8,
+	.has_dmamode = true,
 	.devtype = IMX35_CSPI,
 };
 
@@ -740,6 +747,8 @@ static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
 	.trigger = mx51_ecspi_trigger,
 	.rx_available = mx51_ecspi_rx_available,
 	.reset = mx51_ecspi_reset,
+	.fifo_size = 64,
+	.has_dmamode = true,
 	.devtype = IMX51_ECSPI,
 };
 
@@ -791,7 +800,7 @@ static void spi_imx_chipselect(struct spi_device *spi, int is_active)
 
 static void spi_imx_push(struct spi_imx_data *spi_imx)
 {
-	while (spi_imx->txfifo < spi_imx_get_fifosize(spi_imx)) {
+	while (spi_imx->txfifo < spi_imx->devtype_data->fifo_size) {
 		if (!spi_imx->count)
 			break;
 		spi_imx->tx(spi_imx);
@@ -938,7 +947,7 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	if (of_machine_is_compatible("fsl,imx6dl"))
 		return 0;
 
-	spi_imx->wml = spi_imx_get_fifosize(spi_imx) / 2;
+	spi_imx->wml = spi_imx->devtype_data->fifo_size / 2;
 
 	/* Prepare for TX DMA: */
 	master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
@@ -1262,7 +1271,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 	 * Only validated on i.mx35 and i.mx6 now, can remove the constraint
 	 * if validated on other chips.
 	 */
-	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx)) {
+	if (spi_imx->devtype_data->has_dmamode) {
 		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master);
 		if (ret == -EPROBE_DEFER)
 			goto out_clk_put;
-- 
2.9.3

Applied "spi: imx: introduce fifo_size and has_dmamode in spi_imx_devtype_data" to the spi tree

[Mark Brown]

The patch

   spi: imx: introduce fifo_size and has_dmamode in spi_imx_devtype_data

has been applied to the spi tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 7da0ab95f90271a42cf122b158f14a5578dcf279 Mon Sep 17 00:00:00 2001
From: jiada wang <jiada_wang@mentor.com>
Date: Thu, 8 Jun 2017 14:16:00 +0900
Subject: [PATCH] spi: imx: introduce fifo_size and has_dmamode in
 spi_imx_devtype_data

Different ECSPI controller has different fifosize and DMA capability,
instead of calling functions to identify these information by check
devtype. add fifo_size and has_dmamode to spi_imx_devtype_data.
so that these information can be directly accessed.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-imx.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index f9698b7aeb3b..d3093f355dfb 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -74,6 +74,8 @@ struct spi_imx_devtype_data {
 	void (*trigger)(struct spi_imx_data *);
 	int (*rx_available)(struct spi_imx_data *);
 	void (*reset)(struct spi_imx_data *);
+	bool has_dmamode;
+	unsigned int fifo_size;
 	enum spi_imx_devtype devtype;
 };
 
@@ -125,11 +127,6 @@ static inline int is_imx51_ecspi(struct spi_imx_data *d)
 	return d->devtype_data->devtype == IMX51_ECSPI;
 }
 
-static inline unsigned spi_imx_get_fifosize(struct spi_imx_data *d)
-{
-	return is_imx51_ecspi(d) ? 64 : 8;
-}
-
 #define MXC_SPI_BUF_RX(type)						\
 static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx)		\
 {									\
@@ -219,7 +216,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 	if (bytes_per_word != 1 && bytes_per_word != 2 && bytes_per_word != 4)
 		return false;
 
-	for (i = spi_imx_get_fifosize(spi_imx) / 2; i > 0; i--) {
+	for (i = spi_imx->devtype_data->fifo_size / 2; i > 0; i--) {
 		if (!(transfer->len % (i * bytes_per_word)))
 			break;
 	}
@@ -693,6 +690,8 @@ static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
 	.trigger = mx1_trigger,
 	.rx_available = mx1_rx_available,
 	.reset = mx1_reset,
+	.fifo_size = 8,
+	.has_dmamode = false,
 	.devtype = IMX1_CSPI,
 };
 
@@ -702,6 +701,8 @@ static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
 	.trigger = mx21_trigger,
 	.rx_available = mx21_rx_available,
 	.reset = mx21_reset,
+	.fifo_size = 8,
+	.has_dmamode = false,
 	.devtype = IMX21_CSPI,
 };
 
@@ -712,6 +713,8 @@ static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
 	.trigger = mx21_trigger,
 	.rx_available = mx21_rx_available,
 	.reset = mx21_reset,
+	.fifo_size = 8,
+	.has_dmamode = false,
 	.devtype = IMX27_CSPI,
 };
 
@@ -721,6 +724,8 @@ static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
 	.trigger = mx31_trigger,
 	.rx_available = mx31_rx_available,
 	.reset = mx31_reset,
+	.fifo_size = 8,
+	.has_dmamode = false,
 	.devtype = IMX31_CSPI,
 };
 
@@ -731,6 +736,8 @@ static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
 	.trigger = mx31_trigger,
 	.rx_available = mx31_rx_available,
 	.reset = mx31_reset,
+	.fifo_size = 8,
+	.has_dmamode = true,
 	.devtype = IMX35_CSPI,
 };
 
@@ -740,6 +747,8 @@ static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
 	.trigger = mx51_ecspi_trigger,
 	.rx_available = mx51_ecspi_rx_available,
 	.reset = mx51_ecspi_reset,
+	.fifo_size = 64,
+	.has_dmamode = true,
 	.devtype = IMX51_ECSPI,
 };
 
@@ -791,7 +800,7 @@ static void spi_imx_chipselect(struct spi_device *spi, int is_active)
 
 static void spi_imx_push(struct spi_imx_data *spi_imx)
 {
-	while (spi_imx->txfifo < spi_imx_get_fifosize(spi_imx)) {
+	while (spi_imx->txfifo < spi_imx->devtype_data->fifo_size) {
 		if (!spi_imx->count)
 			break;
 		spi_imx->tx(spi_imx);
@@ -938,7 +947,7 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	if (of_machine_is_compatible("fsl,imx6dl"))
 		return 0;
 
-	spi_imx->wml = spi_imx_get_fifosize(spi_imx) / 2;
+	spi_imx->wml = spi_imx->devtype_data->fifo_size / 2;
 
 	/* Prepare for TX DMA: */
 	master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
@@ -1262,7 +1271,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 	 * Only validated on i.mx35 and i.mx6 now, can remove the constraint
 	 * if validated on other chips.
 	 */
-	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx)) {
+	if (spi_imx->devtype_data->has_dmamode) {
 		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master);
 		if (ret == -EPROBE_DEFER)
 			goto out_clk_put;
-- 
2.13.2

[PATCH linux-next v4 2/4] spi: imx: add selection for iMX53 and iMX6 controller

[Jiada Wang]

ECSPI contorller for iMX53 and iMX6 has few hardware issues
comparing to iMX51.
The change add possibility to detect which controller is used
to apply possible workaround and limitations.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 .../devicetree/bindings/spi/fsl-imx-cspi.txt       |  1 +
 drivers/spi/spi-imx.c                              | 26 ++++++++++++++++++++--
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
index 31b5b21..5bf1396 100644
--- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
+++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
@@ -9,6 +9,7 @@ Required properties:
   - "fsl,imx31-cspi" for SPI compatible with the one integrated on i.MX31
   - "fsl,imx35-cspi" for SPI compatible with the one integrated on i.MX35
   - "fsl,imx51-ecspi" for SPI compatible with the one integrated on i.MX51
+  - "fsl,imx53-ecspi" for SPI compatible with the one integrated on i.MX53 and later Soc
 - reg : Offset and length of the register set for the device
 - interrupts : Should contain CSPI/eCSPI interrupt
 - cs-gpios : Specifies the gpio pins to be used for chipselects.
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 4469121..8e6f339 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -63,7 +63,8 @@ enum spi_imx_devtype {
 	IMX27_CSPI,
 	IMX31_CSPI,
 	IMX35_CSPI,	/* CSPI on all i.mx except above */
-	IMX51_ECSPI,	/* ECSPI on i.mx51 and later */
+	IMX51_ECSPI,	/* ECSPI on i.mx51 */
+	IMX53_ECSPI,	/* ECSPI on i.mx53 and later */
 };
 
 struct spi_imx_data;
@@ -127,6 +128,11 @@ static inline int is_imx51_ecspi(struct spi_imx_data *d)
 	return d->devtype_data->devtype == IMX51_ECSPI;
 }
 
+static inline int is_imx53_ecspi(struct spi_imx_data *d)
+{
+	return d->devtype_data->devtype == IMX53_ECSPI;
+}
+
 #define MXC_SPI_BUF_RX(type)						\
 static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx)		\
 {									\
@@ -752,6 +758,17 @@ static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
 	.devtype = IMX51_ECSPI,
 };
 
+static struct spi_imx_devtype_data imx53_ecspi_devtype_data = {
+	.intctrl = mx51_ecspi_intctrl,
+	.config = mx51_ecspi_config,
+	.trigger = mx51_ecspi_trigger,
+	.rx_available = mx51_ecspi_rx_available,
+	.reset = mx51_ecspi_reset,
+	.fifo_size = 64,
+	.has_dmamode = true,
+	.devtype = IMX53_ECSPI,
+};
+
 static const struct platform_device_id spi_imx_devtype[] = {
 	{
 		.name = "imx1-cspi",
@@ -772,6 +789,9 @@ static const struct platform_device_id spi_imx_devtype[] = {
 		.name = "imx51-ecspi",
 		.driver_data = (kernel_ulong_t) &imx51_ecspi_devtype_data,
 	}, {
+		.name = "imx53-ecspi",
+		.driver_data = (kernel_ulong_t) &imx53_ecspi_devtype_data,
+	}, {
 		/* sentinel */
 	}
 };
@@ -783,6 +803,7 @@ static const struct of_device_id spi_imx_dt_ids[] = {
 	{ .compatible = "fsl,imx31-cspi", .data = &imx31_cspi_devtype_data, },
 	{ .compatible = "fsl,imx35-cspi", .data = &imx35_cspi_devtype_data, },
 	{ .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, },
+	{ .compatible = "fsl,imx53-ecspi", .data = &imx53_ecspi_devtype_data, },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, spi_imx_dt_ids);
@@ -1218,7 +1239,8 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
 	spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
 	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
-	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx))
+	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx) ||
+	    is_imx53_ecspi(spi_imx))
 		spi_imx->bitbang.master->mode_bits |= SPI_LOOP | SPI_READY;
 
 	spi_imx->spi_drctl = spi_drctl;
-- 
2.9.3

Re: [PATCH linux-next v4 2/4] spi: imx: add selection for iMX53 and iMX6 controller

[Rob Herring]

On Thu, Jun 08, 2017 at 02:16:01PM +0900, Jiada Wang wrote:
> ECSPI contorller for iMX53 and iMX6 has few hardware issues
> comparing to iMX51.
> The change add possibility to detect which controller is used
> to apply possible workaround and limitations.
> 
> Signed-off-by: Jiada Wang <jiada_wang-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
> ---
>  .../devicetree/bindings/spi/fsl-imx-cspi.txt       |  1 +
>  drivers/spi/spi-imx.c                              | 26 ++++++++++++++++++++--
>  2 files changed, 25 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
> index 31b5b21..5bf1396 100644
> --- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
> +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
> @@ -9,6 +9,7 @@ Required properties:
>    - "fsl,imx31-cspi" for SPI compatible with the one integrated on i.MX31
>    - "fsl,imx35-cspi" for SPI compatible with the one integrated on i.MX35
>    - "fsl,imx51-ecspi" for SPI compatible with the one integrated on i.MX51
> +  - "fsl,imx53-ecspi" for SPI compatible with the one integrated on i.MX53 and later Soc
>  - reg : Offset and length of the register set for the device
>  - interrupts : Should contain CSPI/eCSPI interrupt
>  - cs-gpios : Specifies the gpio pins to be used for chipselects.
> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
> index 4469121..8e6f339 100644
> --- a/drivers/spi/spi-imx.c
> +++ b/drivers/spi/spi-imx.c
> @@ -63,7 +63,8 @@ enum spi_imx_devtype {
>  	IMX27_CSPI,
>  	IMX31_CSPI,
>  	IMX35_CSPI,	/* CSPI on all i.mx except above */
> -	IMX51_ECSPI,	/* ECSPI on i.mx51 and later */
> +	IMX51_ECSPI,	/* ECSPI on i.mx51 */
> +	IMX53_ECSPI,	/* ECSPI on i.mx53 and later */

Looks like i.MX51 and i.MX53 are the same. While the DT should have 
different compatibles (with fallbacks), the driver should map them to 
the same type until there's some difference found.

Rob
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Re: [PATCH linux-next v4 2/4] spi: imx: add selection for iMX53 and iMX6 controller

[Jiada Wang]

Hello Rob

On 06/13/2017 12:53 AM, Rob Herring wrote:
> On Thu, Jun 08, 2017 at 02:16:01PM +0900, Jiada Wang wrote:
>> ECSPI contorller for iMX53 and iMX6 has few hardware issues
>> comparing to iMX51.
>> The change add possibility to detect which controller is used
>> to apply possible workaround and limitations.
>>
>> Signed-off-by: Jiada Wang <jiada_wang-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
>> ---
>>  .../devicetree/bindings/spi/fsl-imx-cspi.txt       |  1 +
>>  drivers/spi/spi-imx.c                              | 26 ++++++++++++++++++++--
>>  2 files changed, 25 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>> index 31b5b21..5bf1396 100644
>> --- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>> +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>> @@ -9,6 +9,7 @@ Required properties:
>>    - "fsl,imx31-cspi" for SPI compatible with the one integrated on i.MX31
>>    - "fsl,imx35-cspi" for SPI compatible with the one integrated on i.MX35
>>    - "fsl,imx51-ecspi" for SPI compatible with the one integrated on i.MX51
>> +  - "fsl,imx53-ecspi" for SPI compatible with the one integrated on i.MX53 and later Soc
>>  - reg : Offset and length of the register set for the device
>>  - interrupts : Should contain CSPI/eCSPI interrupt
>>  - cs-gpios : Specifies the gpio pins to be used for chipselects.
>> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
>> index 4469121..8e6f339 100644
>> --- a/drivers/spi/spi-imx.c
>> +++ b/drivers/spi/spi-imx.c
>> @@ -63,7 +63,8 @@ enum spi_imx_devtype {
>>  	IMX27_CSPI,
>>  	IMX31_CSPI,
>>  	IMX35_CSPI,	/* CSPI on all i.mx except above */
>> -	IMX51_ECSPI,	/* ECSPI on i.mx51 and later */
>> +	IMX51_ECSPI,	/* ECSPI on i.mx51 */
>> +	IMX53_ECSPI,	/* ECSPI on i.mx53 and later */
>
> Looks like i.MX51 and i.MX53 are the same. While the DT should have
> different compatibles (with fallbacks), the driver should map them to
> the same type until there's some difference found.
>
the difference between i.MX51 and i.MX53 is introduced in the
4th patch "spi: imx: Add support for SPI Slave mode" in this patch set

do you think, I need to merge the two patches into one?

Thanks,
Jiada

> Rob
>
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Re: [PATCH linux-next v4 2/4] spi: imx: add selection for iMX53 and iMX6 controller

[Rob Herring]

On Tue, Jun 13, 2017 at 12:28 AM, Jiada Wang <jiada_wang-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org> wrote:
> Hello Rob
>
>
> On 06/13/2017 12:53 AM, Rob Herring wrote:
>>
>> On Thu, Jun 08, 2017 at 02:16:01PM +0900, Jiada Wang wrote:
>>>
>>> ECSPI contorller for iMX53 and iMX6 has few hardware issues
>>> comparing to iMX51.
>>> The change add possibility to detect which controller is used
>>> to apply possible workaround and limitations.
>>>
>>> Signed-off-by: Jiada Wang <jiada_wang-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
>>> ---
>>>  .../devicetree/bindings/spi/fsl-imx-cspi.txt       |  1 +
>>>  drivers/spi/spi-imx.c                              | 26
>>> ++++++++++++++++++++--
>>>  2 files changed, 25 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>>> b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>>> index 31b5b21..5bf1396 100644
>>> --- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>>> +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>>> @@ -9,6 +9,7 @@ Required properties:
>>>    - "fsl,imx31-cspi" for SPI compatible with the one integrated on
>>> i.MX31
>>>    - "fsl,imx35-cspi" for SPI compatible with the one integrated on
>>> i.MX35
>>>    - "fsl,imx51-ecspi" for SPI compatible with the one integrated on
>>> i.MX51
>>> +  - "fsl,imx53-ecspi" for SPI compatible with the one integrated on
>>> i.MX53 and later Soc
>>>  - reg : Offset and length of the register set for the device
>>>  - interrupts : Should contain CSPI/eCSPI interrupt
>>>  - cs-gpios : Specifies the gpio pins to be used for chipselects.
>>> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
>>> index 4469121..8e6f339 100644
>>> --- a/drivers/spi/spi-imx.c
>>> +++ b/drivers/spi/spi-imx.c
>>> @@ -63,7 +63,8 @@ enum spi_imx_devtype {
>>>         IMX27_CSPI,
>>>         IMX31_CSPI,
>>>         IMX35_CSPI,     /* CSPI on all i.mx except above */
>>> -       IMX51_ECSPI,    /* ECSPI on i.mx51 and later */
>>> +       IMX51_ECSPI,    /* ECSPI on i.mx51 */
>>> +       IMX53_ECSPI,    /* ECSPI on i.mx53 and later */
>>
>>
>> Looks like i.MX51 and i.MX53 are the same. While the DT should have
>> different compatibles (with fallbacks), the driver should map them to
>> the same type until there's some difference found.
>>
> the difference between i.MX51 and i.MX53 is introduced in the
> 4th patch "spi: imx: Add support for SPI Slave mode" in this patch set

Okay, I missed that.

> do you think, I need to merge the two patches into one?

No, not necessary.

Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>

Rob
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Re: [PATCH linux-next v4 2/4] spi: imx: add selection for iMX53 and iMX6 controller

[Jiada Wang]

Hello Mark and Sascha

Could you please review my v4 patch set for i.MX SPI slave support

Thanks,
Jiada

On 06/13/2017 07:29 AM, Rob Herring wrote:
> On Tue, Jun 13, 2017 at 12:28 AM, Jiada Wang<jiada_wang-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>  wrote:
>> Hello Rob
>>
>>
>> On 06/13/2017 12:53 AM, Rob Herring wrote:
>>> On Thu, Jun 08, 2017 at 02:16:01PM +0900, Jiada Wang wrote:
>>>> ECSPI contorller for iMX53 and iMX6 has few hardware issues
>>>> comparing to iMX51.
>>>> The change add possibility to detect which controller is used
>>>> to apply possible workaround and limitations.
>>>>
>>>> Signed-off-by: Jiada Wang<jiada_wang-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
>>>> ---
>>>>   .../devicetree/bindings/spi/fsl-imx-cspi.txt       |  1 +
>>>>   drivers/spi/spi-imx.c                              | 26
>>>> ++++++++++++++++++++--
>>>>   2 files changed, 25 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>>>> b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>>>> index 31b5b21..5bf1396 100644
>>>> --- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>>>> +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
>>>> @@ -9,6 +9,7 @@ Required properties:
>>>>     - "fsl,imx31-cspi" for SPI compatible with the one integrated on
>>>> i.MX31
>>>>     - "fsl,imx35-cspi" for SPI compatible with the one integrated on
>>>> i.MX35
>>>>     - "fsl,imx51-ecspi" for SPI compatible with the one integrated on
>>>> i.MX51
>>>> +  - "fsl,imx53-ecspi" for SPI compatible with the one integrated on
>>>> i.MX53 and later Soc
>>>>   - reg : Offset and length of the register set for the device
>>>>   - interrupts : Should contain CSPI/eCSPI interrupt
>>>>   - cs-gpios : Specifies the gpio pins to be used for chipselects.
>>>> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
>>>> index 4469121..8e6f339 100644
>>>> --- a/drivers/spi/spi-imx.c
>>>> +++ b/drivers/spi/spi-imx.c
>>>> @@ -63,7 +63,8 @@ enum spi_imx_devtype {
>>>>          IMX27_CSPI,
>>>>          IMX31_CSPI,
>>>>          IMX35_CSPI,     /* CSPI on all i.mx except above */
>>>> -       IMX51_ECSPI,    /* ECSPI on i.mx51 and later */
>>>> +       IMX51_ECSPI,    /* ECSPI on i.mx51 */
>>>> +       IMX53_ECSPI,    /* ECSPI on i.mx53 and later */
>>>
>>> Looks like i.MX51 and i.MX53 are the same. While the DT should have
>>> different compatibles (with fallbacks), the driver should map them to
>>> the same type until there's some difference found.
>>>
>> the difference between i.MX51 and i.MX53 is introduced in the
>> 4th patch "spi: imx: Add support for SPI Slave mode" in this patch set
> Okay, I missed that.
>
>> do you think, I need to merge the two patches into one?
> No, not necessary.
>
> Acked-by: Rob Herring<robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
>
> Rob

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Re: [PATCH linux-next v4 2/4] spi: imx: add selection for iMX53 and iMX6 controller

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 684 bytes --]

On Mon, Jun 26, 2017 at 06:25:52PM -0700, Jiada Wang wrote:
> Hello Mark and Sascha
> 
> Could you please review my v4 patch set for i.MX SPI slave support

Please don't send content free pings and please allow a reasonable time
for review.  People get busy, go on holiday, attend conferences and so 
on so unless there is some reason for urgency (like critical bug fixes)
please allow at least a couple of weeks for review.  If there have been
review comments then people may be waiting for those to be addressed.
Sending content free pings just adds to the mail volume (if they are
seen at all) and if something has gone wrong you'll have to resend the
patches anyway.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

[PATCH linux-next v4 3/4] ARM: dts: imx: change compatibility for SPI controllers on imx53 later soc

[Jiada Wang]

for SPI controllers on imx53 and later SoCs, there is HW issue when
work in slave mode, as new device type 'IMX53_ECSPI' has been added
for these SPI controllers which is compatible with 'fsl,imx53-ecspi'.

This patch updates DTS to make imx53 later SPI controller only be
compatibile with 'fsl,imx53-ecspi'.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 arch/arm/boot/dts/imx53.dtsi   | 4 ++--
 arch/arm/boot/dts/imx6q.dtsi   | 2 +-
 arch/arm/boot/dts/imx6qdl.dtsi | 8 ++++----
 arch/arm/boot/dts/imx6sl.dtsi  | 8 ++++----
 arch/arm/boot/dts/imx6sx.dtsi  | 8 ++++----
 arch/arm/boot/dts/imx6ul.dtsi  | 8 ++++----
 6 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/arch/arm/boot/dts/imx53.dtsi b/arch/arm/boot/dts/imx53.dtsi
index 2e516f4..9eeafb9 100644
--- a/arch/arm/boot/dts/imx53.dtsi
+++ b/arch/arm/boot/dts/imx53.dtsi
@@ -243,7 +243,7 @@
 				ecspi1: ecspi@50010000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx53-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx53-ecspi";
 					reg = <0x50010000 0x4000>;
 					interrupts = <36>;
 					clocks = <&clks IMX5_CLK_ECSPI1_IPG_GATE>,
@@ -662,7 +662,7 @@
 			ecspi2: ecspi@63fac000 {
 				#address-cells = <1>;
 				#size-cells = <0>;
-				compatible = "fsl,imx53-ecspi", "fsl,imx51-ecspi";
+				compatible = "fsl,imx53-ecspi";
 				reg = <0x63fac000 0x4000>;
 				interrupts = <37>;
 				clocks = <&clks IMX5_CLK_ECSPI2_IPG_GATE>,
diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
index dd33849..b214442 100644
--- a/arch/arm/boot/dts/imx6q.dtsi
+++ b/arch/arm/boot/dts/imx6q.dtsi
@@ -90,7 +90,7 @@
 				ecspi5: ecspi@02018000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6q-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6q-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02018000 0x4000>;
 					interrupts = <0 35 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6Q_CLK_ECSPI5>,
diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
index f325411..ac19c58 100644
--- a/arch/arm/boot/dts/imx6qdl.dtsi
+++ b/arch/arm/boot/dts/imx6qdl.dtsi
@@ -266,7 +266,7 @@
 				ecspi1: ecspi@02008000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6q-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6q-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02008000 0x4000>;
 					interrupts = <0 31 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6QDL_CLK_ECSPI1>,
@@ -280,7 +280,7 @@
 				ecspi2: ecspi@0200c000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6q-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6q-ecspi", "fsl,imx53-ecspi";
 					reg = <0x0200c000 0x4000>;
 					interrupts = <0 32 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6QDL_CLK_ECSPI2>,
@@ -294,7 +294,7 @@
 				ecspi3: ecspi@02010000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6q-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6q-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02010000 0x4000>;
 					interrupts = <0 33 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6QDL_CLK_ECSPI3>,
@@ -308,7 +308,7 @@
 				ecspi4: ecspi@02014000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6q-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6q-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02014000 0x4000>;
 					interrupts = <0 34 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6QDL_CLK_ECSPI4>,
diff --git a/arch/arm/boot/dts/imx6sl.dtsi b/arch/arm/boot/dts/imx6sl.dtsi
index 3243af4..d9b9053 100644
--- a/arch/arm/boot/dts/imx6sl.dtsi
+++ b/arch/arm/boot/dts/imx6sl.dtsi
@@ -168,7 +168,7 @@
 				ecspi1: ecspi@02008000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6sl-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6sl-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02008000 0x4000>;
 					interrupts = <0 31 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6SL_CLK_ECSPI1>,
@@ -180,7 +180,7 @@
 				ecspi2: ecspi@0200c000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6sl-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6sl-ecspi", "fsl,imx53-ecspi";
 					reg = <0x0200c000 0x4000>;
 					interrupts = <0 32 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6SL_CLK_ECSPI2>,
@@ -192,7 +192,7 @@
 				ecspi3: ecspi@02010000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6sl-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6sl-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02010000 0x4000>;
 					interrupts = <0 33 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6SL_CLK_ECSPI3>,
@@ -204,7 +204,7 @@
 				ecspi4: ecspi@02014000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6sl-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6sl-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02014000 0x4000>;
 					interrupts = <0 34 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6SL_CLK_ECSPI4>,
diff --git a/arch/arm/boot/dts/imx6sx.dtsi b/arch/arm/boot/dts/imx6sx.dtsi
index f16b9df..149ef79 100644
--- a/arch/arm/boot/dts/imx6sx.dtsi
+++ b/arch/arm/boot/dts/imx6sx.dtsi
@@ -251,7 +251,7 @@
 				ecspi1: ecspi@02008000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6sx-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6sx-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02008000 0x4000>;
 					interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6SX_CLK_ECSPI1>,
@@ -263,7 +263,7 @@
 				ecspi2: ecspi@0200c000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6sx-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6sx-ecspi", "fsl,imx53-ecspi";
 					reg = <0x0200c000 0x4000>;
 					interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6SX_CLK_ECSPI2>,
@@ -275,7 +275,7 @@
 				ecspi3: ecspi@02010000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6sx-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6sx-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02010000 0x4000>;
 					interrupts = <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6SX_CLK_ECSPI3>,
@@ -287,7 +287,7 @@
 				ecspi4: ecspi@02014000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6sx-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6sx-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02014000 0x4000>;
 					interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6SX_CLK_ECSPI4>,
diff --git a/arch/arm/boot/dts/imx6ul.dtsi b/arch/arm/boot/dts/imx6ul.dtsi
index 6da2b77..7226061 100644
--- a/arch/arm/boot/dts/imx6ul.dtsi
+++ b/arch/arm/boot/dts/imx6ul.dtsi
@@ -204,7 +204,7 @@
 				ecspi1: ecspi@02008000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6ul-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6ul-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02008000 0x4000>;
 					interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6UL_CLK_ECSPI1>,
@@ -216,7 +216,7 @@
 				ecspi2: ecspi@0200c000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6ul-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6ul-ecspi", "fsl,imx53-ecspi";
 					reg = <0x0200c000 0x4000>;
 					interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6UL_CLK_ECSPI2>,
@@ -228,7 +228,7 @@
 				ecspi3: ecspi@02010000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6ul-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6ul-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02010000 0x4000>;
 					interrupts = <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6UL_CLK_ECSPI3>,
@@ -240,7 +240,7 @@
 				ecspi4: ecspi@02014000 {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					compatible = "fsl,imx6ul-ecspi", "fsl,imx51-ecspi";
+					compatible = "fsl,imx6ul-ecspi", "fsl,imx53-ecspi";
 					reg = <0x02014000 0x4000>;
 					interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6UL_CLK_ECSPI4>,
-- 
2.9.3

[PATCH linux-next v4 4/4] spi: imx: Add support for SPI Slave mode

[Jiada Wang]

Previously i.MX SPI controller only works in Master mode.
This patch adds support to i.MX51, i.MX53 and i.MX6 ECSPI
controller to work also in Slave mode.

Currently SPI Slave mode support patch has the following limitations:
1. The stale data in RXFIFO will be dropped when the Slave does any new
   transfer.
2. One transfer can be finished only after all transfer->len data been
   transferred to master device
3. Slave device only accepts transfer->len data. Any data longer than this
   from master device will be dropped. Any data shorter than this from
   master will cause SPI to stuck due to mentioned HW limitation 2.
4. Only PIO transfer is supported in Slave mode.

Following HW limitation applies:
1.  ECSPI has a HW issue when works in Slave mode, after 64
    words written to TXFIFO, even TXFIFO becomes empty,
    ECSPI_TXDATA keeps shift out the last word data,
    so we have to disable ECSPI when in slave mode after the
    transfer completes
2.  Due to Freescale errata ERR003775 "eCSPI: Burst completion by Chip
    Select (SS) signal in Slave mode is not functional" burst size must
    be set exactly to the size of the transfer. This limit SPI transaction
    with maximum 2^12 bits. This errata affects i.MX53 and i.MX6 ECSPI
    controllers.

Signed-off-by: Jiada Wang <jiada_wang-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
---
 drivers/spi/spi-imx.c | 226 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 196 insertions(+), 30 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 8e6f339..8211cad 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -53,9 +53,12 @@
 /* generic defines to abstract from the different register layouts */
 #define MXC_INT_RR	(1 << 0) /* Receive data ready interrupt */
 #define MXC_INT_TE	(1 << 1) /* Transmit FIFO empty interrupt */
+#define MXC_INT_RDR	BIT(4) /* Receive date threshold interrupt */
 
 /* The maximum  bytes that a sdma BD can transfer.*/
 #define MAX_SDMA_BD_BYTES  (1 << 15)
+/* The maximum bytes that IMX53_ECSPI can transfer in slave mode.*/
+#define MX53_MAX_TRANSFER_BYTES		512
 
 enum spi_imx_devtype {
 	IMX1_CSPI,
@@ -75,7 +78,9 @@ struct spi_imx_devtype_data {
 	void (*trigger)(struct spi_imx_data *);
 	int (*rx_available)(struct spi_imx_data *);
 	void (*reset)(struct spi_imx_data *);
+	void (*disable)(struct spi_imx_data *);
 	bool has_dmamode;
+	bool has_slavemode;
 	unsigned int fifo_size;
 	enum spi_imx_devtype devtype;
 };
@@ -104,6 +109,11 @@ struct spi_imx_data {
 	const void *tx_buf;
 	unsigned int txfifo; /* number of words pushed in tx FIFO */
 
+	/* Slave mode */
+	bool slave_mode;
+	bool slave_aborted;
+	unsigned int slave_burst;
+
 	/* DMA */
 	bool usedma;
 	u32 wml;
@@ -217,6 +227,9 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 	if (!master->dma_rx)
 		return false;
 
+	if (spi_imx->slave_mode)
+		return false;
+
 	bytes_per_word = spi_imx_bytes_per_word(transfer->bits_per_word);
 
 	if (bytes_per_word != 1 && bytes_per_word != 2 && bytes_per_word != 4)
@@ -256,6 +269,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 #define MX51_ECSPI_INT		0x10
 #define MX51_ECSPI_INT_TEEN		(1 <<  0)
 #define MX51_ECSPI_INT_RREN		(1 <<  3)
+#define MX51_ECSPI_INT_RDREN		(1 <<  4)
 
 #define MX51_ECSPI_DMA      0x14
 #define MX51_ECSPI_DMA_TX_WML(wml)	((wml) & 0x3f)
@@ -272,6 +286,44 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 #define MX51_ECSPI_TESTREG	0x20
 #define MX51_ECSPI_TESTREG_LBC	BIT(31)
 
+static void mx53_ecspi_rx_slave(struct spi_imx_data *spi_imx)
+{
+	u32 val = be32_to_cpu(readl(spi_imx->base + MXC_CSPIRXDATA));
+
+	if (spi_imx->rx_buf) {
+		int n_bytes = spi_imx->slave_burst % sizeof(val);
+
+		if (!n_bytes)
+			n_bytes = sizeof(val);
+
+		memcpy(spi_imx->rx_buf,
+		       ((u8 *)&val) + sizeof(val) - n_bytes, n_bytes);
+
+		spi_imx->rx_buf += n_bytes;
+		spi_imx->slave_burst -= n_bytes;
+	}
+}
+
+static void mx53_ecspi_tx_slave(struct spi_imx_data *spi_imx)
+{
+	u32 val = 0;
+	int n_bytes = spi_imx->count % sizeof(val);
+
+	if (!n_bytes)
+		n_bytes = sizeof(val);
+
+	if (spi_imx->tx_buf) {
+		memcpy(((u8 *)&val) + sizeof(val) - n_bytes,
+		       spi_imx->tx_buf, n_bytes);
+		val = cpu_to_be32(val);
+		spi_imx->tx_buf += n_bytes;
+	}
+
+	spi_imx->count -= n_bytes;
+
+	writel(val, spi_imx->base + MXC_CSPITXDATA);
+}
+
 /* MX51 eCSPI */
 static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx,
 				      unsigned int fspi, unsigned int *fres)
@@ -321,6 +373,9 @@ static void mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable)
 	if (enable & MXC_INT_RR)
 		val |= MX51_ECSPI_INT_RREN;
 
+	if (enable & MXC_INT_RDR)
+		val |= MX51_ECSPI_INT_RDREN;
+
 	writel(val, spi_imx->base + MX51_ECSPI_INT);
 }
 
@@ -333,6 +388,15 @@ static void mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
 	writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
 }
 
+static void mx51_ecspi_disable(struct spi_imx_data *spi_imx)
+{
+	u32 ctrl;
+
+	ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
+	ctrl &= ~MX51_ECSPI_CTRL_ENABLE;
+	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
+}
+
 static int mx51_ecspi_config(struct spi_device *spi)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
@@ -340,14 +404,11 @@ static int mx51_ecspi_config(struct spi_device *spi)
 	u32 clk = spi_imx->speed_hz, delay, reg;
 	u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
 
-	/*
-	 * The hardware seems to have a race condition when changing modes. The
-	 * current assumption is that the selection of the channel arrives
-	 * earlier in the hardware than the mode bits when they are written at
-	 * the same time.
-	 * So set master mode for all channels as we do not support slave mode.
-	 */
-	ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
+	/* set Master or Slave mode */
+	if (spi_imx->slave_mode)
+		ctrl &= ~MX51_ECSPI_CTRL_MODE_MASK;
+	else
+		ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
 
 	/*
 	 * Enable SPI_RDY handling (falling edge/level triggered).
@@ -362,9 +423,22 @@ static int mx51_ecspi_config(struct spi_device *spi)
 	/* set chip select to use */
 	ctrl |= MX51_ECSPI_CTRL_CS(spi->chip_select);
 
-	ctrl |= (spi_imx->bits_per_word - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
+	if (spi_imx->slave_mode && is_imx53_ecspi(spi_imx))
+		ctrl |= (spi_imx->slave_burst * 8 - 1)
+			<< MX51_ECSPI_CTRL_BL_OFFSET;
+	else
+		ctrl |= (spi_imx->bits_per_word - 1)
+			<< MX51_ECSPI_CTRL_BL_OFFSET;
 
-	cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
+	/*
+	 * eCSPI burst completion by Chip Select signal in Slave mode
+	 * is not functional for imx53 Soc, config SPI burst completed when
+	 * BURST_LENGTH + 1 bits are received
+	 */
+	if (spi_imx->slave_mode && is_imx53_ecspi(spi_imx))
+		cfg &= ~MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
+	else
+		cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
 
 	if (spi->mode & SPI_CPHA)
 		cfg |= MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);
@@ -698,6 +772,7 @@ static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
 	.reset = mx1_reset,
 	.fifo_size = 8,
 	.has_dmamode = false,
+	.has_slavemode = false,
 	.devtype = IMX1_CSPI,
 };
 
@@ -709,6 +784,7 @@ static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
 	.reset = mx21_reset,
 	.fifo_size = 8,
 	.has_dmamode = false,
+	.has_slavemode = false,
 	.devtype = IMX21_CSPI,
 };
 
@@ -721,6 +797,7 @@ static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
 	.reset = mx21_reset,
 	.fifo_size = 8,
 	.has_dmamode = false,
+	.has_slavemode = false,
 	.devtype = IMX27_CSPI,
 };
 
@@ -732,6 +809,7 @@ static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
 	.reset = mx31_reset,
 	.fifo_size = 8,
 	.has_dmamode = false,
+	.has_slavemode = false,
 	.devtype = IMX31_CSPI,
 };
 
@@ -744,6 +822,7 @@ static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
 	.reset = mx31_reset,
 	.fifo_size = 8,
 	.has_dmamode = true,
+	.has_slavemode = false,
 	.devtype = IMX35_CSPI,
 };
 
@@ -755,6 +834,8 @@ static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
 	.reset = mx51_ecspi_reset,
 	.fifo_size = 64,
 	.has_dmamode = true,
+	.has_slavemode = true,
+	.disable = mx51_ecspi_disable,
 	.devtype = IMX51_ECSPI,
 };
 
@@ -766,6 +847,8 @@ static struct spi_imx_devtype_data imx53_ecspi_devtype_data = {
 	.reset = mx51_ecspi_reset,
 	.fifo_size = 64,
 	.has_dmamode = true,
+	.has_slavemode = true,
+	.disable = mx51_ecspi_disable,
 	.devtype = IMX53_ECSPI,
 };
 
@@ -828,14 +911,16 @@ static void spi_imx_push(struct spi_imx_data *spi_imx)
 		spi_imx->txfifo++;
 	}
 
-	spi_imx->devtype_data->trigger(spi_imx);
+	if (!spi_imx->slave_mode)
+		spi_imx->devtype_data->trigger(spi_imx);
 }
 
 static irqreturn_t spi_imx_isr(int irq, void *dev_id)
 {
 	struct spi_imx_data *spi_imx = dev_id;
 
-	while (spi_imx->devtype_data->rx_available(spi_imx)) {
+	while (spi_imx->txfifo &&
+	       spi_imx->devtype_data->rx_available(spi_imx)) {
 		spi_imx->rx(spi_imx);
 		spi_imx->txfifo--;
 	}
@@ -939,6 +1024,12 @@ static int spi_imx_setupxfer(struct spi_device *spi,
 			return ret;
 	}
 
+	if (is_imx53_ecspi(spi_imx) && spi_imx->slave_mode) {
+		spi_imx->rx = mx53_ecspi_rx_slave;
+		spi_imx->tx = mx53_ecspi_tx_slave;
+		spi_imx->slave_burst = t->len;
+	}
+
 	spi_imx->devtype_data->config(spi);
 
 	return 0;
@@ -1123,11 +1214,61 @@ static int spi_imx_pio_transfer(struct spi_device *spi,
 	return transfer->len;
 }
 
+static int spi_imx_pio_transfer_slave(struct spi_device *spi,
+				      struct spi_transfer *transfer)
+{
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+	int ret = transfer->len;
+
+	if (is_imx53_ecspi(spi_imx) &&
+	    transfer->len > MX53_MAX_TRANSFER_BYTES) {
+		dev_err(&spi->dev, "Transaction too big, max size is %d bytes\n",
+			MX53_MAX_TRANSFER_BYTES);
+		return -EMSGSIZE;
+	}
+
+	spi_imx->tx_buf = transfer->tx_buf;
+	spi_imx->rx_buf = transfer->rx_buf;
+	spi_imx->count = transfer->len;
+	spi_imx->txfifo = 0;
+
+	reinit_completion(&spi_imx->xfer_done);
+	spi_imx->slave_aborted = false;
+
+	spi_imx_push(spi_imx);
+
+	spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE | MXC_INT_RDR);
+
+	if (wait_for_completion_interruptible(&spi_imx->xfer_done) ||
+	    spi_imx->slave_aborted) {
+		dev_dbg(&spi->dev, "interrupted\n");
+		ret = -EINTR;
+	}
+
+	/* ecspi has a HW issue when works in Slave mode,
+	 * after 64 words writtern to TXFIFO, even TXFIFO becomes empty,
+	 * ECSPI_TXDATA keeps shift out the last word data,
+	 * so we have to disable ECSPI when in slave mode after the
+	 * transfer completes
+	 */
+	if (spi_imx->devtype_data->disable)
+		spi_imx->devtype_data->disable(spi_imx);
+
+	return ret;
+}
+
 static int spi_imx_transfer(struct spi_device *spi,
 				struct spi_transfer *transfer)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
 
+	/* flush rxfifo before transfer */
+	while (spi_imx->devtype_data->rx_available(spi_imx))
+		spi_imx->rx(spi_imx);
+
+	if (spi_imx->slave_mode)
+		return spi_imx_pio_transfer_slave(spi, transfer);
+
 	if (spi_imx->usedma)
 		return spi_imx_dma_transfer(spi_imx, transfer);
 	else
@@ -1181,6 +1322,16 @@ spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg)
 	return 0;
 }
 
+static int spi_imx_slave_abort(struct spi_master *master)
+{
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+
+	spi_imx->slave_aborted = true;
+	complete(&spi_imx->xfer_done);
+
+	return 0;
+}
+
 static int spi_imx_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -1192,13 +1343,24 @@ static int spi_imx_probe(struct platform_device *pdev)
 	struct spi_imx_data *spi_imx;
 	struct resource *res;
 	int i, ret, irq, spi_drctl;
+	const struct spi_imx_devtype_data *devtype_data = of_id ? of_id->data :
+		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
+	bool slave_mode;
 
 	if (!np && !mxc_platform_info) {
 		dev_err(&pdev->dev, "can't get the platform data\n");
 		return -EINVAL;
 	}
 
-	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data));
+	slave_mode = devtype_data->has_slavemode &&
+			of_property_read_bool(np, "spi-slave");
+	if (slave_mode)
+		master = spi_alloc_slave(&pdev->dev,
+					 sizeof(struct spi_imx_data));
+	else
+		master = spi_alloc_master(&pdev->dev,
+					  sizeof(struct spi_imx_data));
+
 	ret = of_property_read_u32(np, "fsl,spi-rdy-drctl", &spi_drctl);
 	if ((ret < 0) || (spi_drctl >= 0x3)) {
 		/* '11' is reserved */
@@ -1216,9 +1378,9 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx = spi_master_get_devdata(master);
 	spi_imx->bitbang.master = master;
 	spi_imx->dev = &pdev->dev;
+	spi_imx->slave_mode = slave_mode;
 
-	spi_imx->devtype_data = of_id ? of_id->data :
-		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
+	spi_imx->devtype_data = devtype_data;
 
 	if (mxc_platform_info) {
 		master->num_chipselect = mxc_platform_info->num_chipselect;
@@ -1238,6 +1400,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
 	spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
 	spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
+	spi_imx->bitbang.master->slave_abort = spi_imx_slave_abort;
 	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
 	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx) ||
 	    is_imx53_ecspi(spi_imx))
@@ -1314,23 +1477,26 @@ static int spi_imx_probe(struct platform_device *pdev)
 		goto out_clk_put;
 	}
 
-	if (!master->cs_gpios) {
-		dev_err(&pdev->dev, "No CS GPIOs available\n");
-		ret = -EINVAL;
-		goto out_clk_put;
-	}
-
-	for (i = 0; i < master->num_chipselect; i++) {
-		if (!gpio_is_valid(master->cs_gpios[i]))
-			continue;
-
-		ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
-					DRIVER_NAME);
-		if (ret) {
-			dev_err(&pdev->dev, "Can't get CS GPIO %i\n",
-				master->cs_gpios[i]);
+	if (!spi_imx->slave_mode) {
+		if (!master->cs_gpios) {
+			dev_err(&pdev->dev, "No CS GPIOs available\n");
+			ret = -EINVAL;
 			goto out_clk_put;
 		}
+
+		for (i = 0; i < master->num_chipselect; i++) {
+			if (!gpio_is_valid(master->cs_gpios[i]))
+				continue;
+
+			ret = devm_gpio_request(&pdev->dev,
+						master->cs_gpios[i],
+						DRIVER_NAME);
+			if (ret) {
+				dev_err(&pdev->dev, "Can't get CS GPIO %i\n",
+					master->cs_gpios[i]);
+				goto out_clk_put;
+			}
+		}
 	}
 
 	dev_info(&pdev->dev, "probed\n");
-- 
2.9.3

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Re: [PATCH linux-next v4 4/4] spi: imx: Add support for SPI Slave mode

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 288 bytes --]

On Thu, Jun 08, 2017 at 02:16:03PM +0900, Jiada Wang wrote:
> Previously i.MX SPI controller only works in Master mode.
> This patch adds support to i.MX51, i.MX53 and i.MX6 ECSPI
> controller to work also in Slave mode.

This doesn't apply against current code, please check and resend.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH linux-next v4 0/4] i.MX ECSPI controller slave mode support

[Sascha Hauer]

On Thu, Jun 08, 2017 at 02:15:59PM +0900, Jiada Wang wrote:
> Changes in v4:
> * rebased to head of linux-next to resolve conflict
> * optimized mx53_ecspi_rx_slave()
> 
> Changes in v3:
> * renamed several variables for for better readability
> * created spi_imx_pio_transfer_slave() for slave pio transfer
> * added fifo_size, has_dmamode and has_slavemode in spi_imx_devtype_data
> 
> Changes in v2:
> * re-workd i.MX ECSPI controller slave mode support based on Geert's work
> 
> Jiada Wang (4):
>   spi: imx: introduce fifo_size and has_dmamode in spi_imx_devtype_data
>   spi: imx: add selection for iMX53 and iMX6 controller
>   ARM: dts: imx: change compatibility for SPI controllers on imx53 later
>     soc
>   spi: imx: Add support for SPI Slave mode

For the series:

Reviewed-by: Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>

Sascha


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[PATCH linux-next v3 0/4] i.MX ECSPI controller slave mode support

[Jiada Wang]

Changes in v3:
* renamed several variables for for better readability
* created spi_imx_pio_transfer_slave() for slave pio transfer
* added fifo_size, has_dmamode and has_slavemode in spi_imx_devtype_data

Changes in v2:
* re-workd i.MX ECSPI controller slave mode support based on Geert's work

Jiada Wang (4):
  spi: imx: introduce fifo_size and has_dmamode in spi_imx_devtype_data
  spi: imx: add selection for iMX53 and iMX6 controller
  ARM: dts: imx: change compatiblity for SPI controllers on imx53 later
    soc
  spi: imx: Add support for SPI Slave mode

 .../devicetree/bindings/spi/fsl-imx-cspi.txt       |   1 +
 arch/arm/boot/dts/imx53.dtsi                       |   4 +-
 arch/arm/boot/dts/imx6q.dtsi                       |   2 +-
 arch/arm/boot/dts/imx6qdl.dtsi                     |   8 +-
 arch/arm/boot/dts/imx6sl.dtsi                      |   8 +-
 arch/arm/boot/dts/imx6sx.dtsi                      |   8 +-
 arch/arm/boot/dts/imx6ul.dtsi                      |   8 +-
 drivers/spi/spi-imx.c                              | 275 ++++++++++++++++++---
 8 files changed, 257 insertions(+), 57 deletions(-)

-- 
2.9.3

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[PATCH linux-next v4 4/4] spi: imx: Add support for SPI Slave mode

[Jiada Wang]

Previously i.MX SPI controller only works in Master mode.
This patch adds support to i.MX51, i.MX53 and i.MX6 ECSPI
controller to work also in Slave mode.

Currently SPI Slave mode support patch has the following limitations:
1. The stale data in RXFIFO will be dropped when the Slave does any new
   transfer.
2. One transfer can be finished only after all transfer->len data been
   transferred to master device
3. Slave device only accepts transfer->len data. Any data longer than this
   from master device will be dropped. Any data shorter than this from
   master will cause SPI to stuck due to mentioned HW limitation 2.
4. Only PIO transfer is supported in Slave mode.

Following HW limitation applies:
1.  ECSPI has a HW issue when works in Slave mode, after 64
    words written to TXFIFO, even TXFIFO becomes empty,
    ECSPI_TXDATA keeps shift out the last word data,
    so we have to disable ECSPI when in slave mode after the
    transfer completes
2.  Due to Freescale errata ERR003775 "eCSPI: Burst completion by Chip
    Select (SS) signal in Slave mode is not functional" burst size must
    be set exactly to the size of the transfer. This limit SPI transaction
    with maximum 2^12 bits. This errata affects i.MX53 and i.MX6 ECSPI
    controllers.

Signed-off-by: Jiada Wang <jiada_wang-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
---
 drivers/spi/spi-imx.c | 228 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 198 insertions(+), 30 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 5034f89..3db3809 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -53,9 +53,13 @@
 /* generic defines to abstract from the different register layouts */
 #define MXC_INT_RR	(1 << 0) /* Receive data ready interrupt */
 #define MXC_INT_TE	(1 << 1) /* Transmit FIFO empty interrupt */
+#define MXC_INT_RDR	BIT(4) /* Receive date threshold interrupt */
 
 /* The maximum  bytes that a sdma BD can transfer.*/
 #define MAX_SDMA_BD_BYTES  (1 << 15)
+/* The maximum bytes that IMX53_ECSPI can transfer in slave mode.*/
+#define MX53_MAX_TRANSFER_BYTES		512
+
 struct spi_imx_config {
 	unsigned int speed_hz;
 	unsigned int bpw;
@@ -79,7 +83,9 @@ struct spi_imx_devtype_data {
 	void (*trigger)(struct spi_imx_data *);
 	int (*rx_available)(struct spi_imx_data *);
 	void (*reset)(struct spi_imx_data *);
+	void (*disable)(struct spi_imx_data *);
 	bool has_dmamode;
+	bool has_slavemode;
 	unsigned int fifo_size;
 	enum spi_imx_devtype devtype;
 };
@@ -107,6 +113,11 @@ struct spi_imx_data {
 	const void *tx_buf;
 	unsigned int txfifo; /* number of words pushed in tx FIFO */
 
+	/* Slave mode */
+	bool slave_mode;
+	bool slave_aborted;
+	unsigned int slave_burst;
+
 	/* DMA */
 	bool usedma;
 	u32 wml;
@@ -223,6 +234,9 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 	if (!transfer)
 		return false;
 
+	if (spi_imx->slave_mode)
+		return false;
+
 	bpw = transfer->bits_per_word;
 	if (!bpw)
 		bpw = spi->bits_per_word;
@@ -266,6 +280,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 #define MX51_ECSPI_INT		0x10
 #define MX51_ECSPI_INT_TEEN		(1 <<  0)
 #define MX51_ECSPI_INT_RREN		(1 <<  3)
+#define MX51_ECSPI_INT_RDREN		(1 <<  4)
 
 #define MX51_ECSPI_DMA      0x14
 #define MX51_ECSPI_DMA_TX_WML(wml)	((wml) & 0x3f)
@@ -282,6 +297,46 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 #define MX51_ECSPI_TESTREG	0x20
 #define MX51_ECSPI_TESTREG_LBC	BIT(31)
 
+static void mx53_ecspi_rx_slave(struct spi_imx_data *spi_imx)
+{
+	u32 val = be32_to_cpu(readl(spi_imx->base + MXC_CSPIRXDATA));
+
+	if (spi_imx->rx_buf) {
+		int n_bytes = spi_imx->slave_burst % sizeof(val);
+
+		if (n_bytes) {
+			memcpy(spi_imx->rx_buf,
+			       ((u8 *)&val) + sizeof(val) - n_bytes, n_bytes);
+		} else {
+			*((u32 *)spi_imx->rx_buf) = val;
+			n_bytes = sizeof(val);
+		}
+
+		spi_imx->rx_buf += n_bytes;
+		spi_imx->slave_burst -= n_bytes;
+	}
+}
+
+static void mx53_ecspi_tx_slave(struct spi_imx_data *spi_imx)
+{
+	u32 val = 0;
+	int n_bytes = spi_imx->count % sizeof(val);
+
+	if (!n_bytes)
+		n_bytes = sizeof(val);
+
+	if (spi_imx->tx_buf) {
+		memcpy(((u8 *)&val) + sizeof(val) - n_bytes,
+		       spi_imx->tx_buf, n_bytes);
+		val = cpu_to_be32(val);
+		spi_imx->tx_buf += n_bytes;
+	}
+
+	spi_imx->count -= n_bytes;
+
+	writel(val, spi_imx->base + MXC_CSPITXDATA);
+}
+
 /* MX51 eCSPI */
 static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx,
 				      unsigned int fspi, unsigned int *fres)
@@ -331,6 +386,9 @@ static void mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable)
 	if (enable & MXC_INT_RR)
 		val |= MX51_ECSPI_INT_RREN;
 
+	if (enable & MXC_INT_RDR)
+		val |= MX51_ECSPI_INT_RDREN;
+
 	writel(val, spi_imx->base + MX51_ECSPI_INT);
 }
 
@@ -343,6 +401,15 @@ static void mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
 	writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
 }
 
+static void mx51_ecspi_disable(struct spi_imx_data *spi_imx)
+{
+	u32 ctrl;
+
+	ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
+	ctrl &= ~MX51_ECSPI_CTRL_ENABLE;
+	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
+}
+
 static int mx51_ecspi_config(struct spi_device *spi,
 			     struct spi_imx_config *config)
 {
@@ -351,14 +418,11 @@ static int mx51_ecspi_config(struct spi_device *spi,
 	u32 clk = config->speed_hz, delay, reg;
 	u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
 
-	/*
-	 * The hardware seems to have a race condition when changing modes. The
-	 * current assumption is that the selection of the channel arrives
-	 * earlier in the hardware than the mode bits when they are written at
-	 * the same time.
-	 * So set master mode for all channels as we do not support slave mode.
-	 */
-	ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
+	/* set Master or Slave mode */
+	if (spi_imx->slave_mode)
+		ctrl &= ~MX51_ECSPI_CTRL_MODE_MASK;
+	else
+		ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
 
 	/*
 	 * Enable SPI_RDY handling (falling edge/level triggered).
@@ -373,9 +437,21 @@ static int mx51_ecspi_config(struct spi_device *spi,
 	/* set chip select to use */
 	ctrl |= MX51_ECSPI_CTRL_CS(spi->chip_select);
 
-	ctrl |= (config->bpw - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
+	if (spi_imx->slave_mode && is_imx53_ecspi(spi_imx))
+		ctrl |= (spi_imx->slave_burst * 8 - 1)
+			<< MX51_ECSPI_CTRL_BL_OFFSET;
+	else
+		ctrl |= (config->bpw - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
 
-	cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
+	/*
+	 * eCSPI burst completion by Chip Select signal in Slave mode
+	 * is not functional for imx53 Soc, config SPI burst completed when
+	 * BURST_LENGTH + 1 bits are received
+	 */
+	if (spi_imx->slave_mode && is_imx53_ecspi(spi_imx))
+		cfg &= ~MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
+	else
+		cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
 
 	if (spi->mode & SPI_CPHA)
 		cfg |= MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);
@@ -709,6 +785,7 @@ static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
 	.reset = mx1_reset,
 	.fifo_size = 8,
 	.has_dmamode = false,
+	.has_slavemode = false,
 	.devtype = IMX1_CSPI,
 };
 
@@ -720,6 +797,7 @@ static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
 	.reset = mx21_reset,
 	.fifo_size = 8,
 	.has_dmamode = false,
+	.has_slavemode = false,
 	.devtype = IMX21_CSPI,
 };
 
@@ -732,6 +810,7 @@ static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
 	.reset = mx21_reset,
 	.fifo_size = 8,
 	.has_dmamode = false,
+	.has_slavemode = false,
 	.devtype = IMX27_CSPI,
 };
 
@@ -743,6 +822,7 @@ static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
 	.reset = mx31_reset,
 	.fifo_size = 8,
 	.has_dmamode = false,
+	.has_slavemode = false,
 	.devtype = IMX31_CSPI,
 };
 
@@ -755,6 +835,7 @@ static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
 	.reset = mx31_reset,
 	.fifo_size = 8,
 	.has_dmamode = true,
+	.has_slavemode = false,
 	.devtype = IMX35_CSPI,
 };
 
@@ -766,6 +847,8 @@ static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
 	.reset = mx51_ecspi_reset,
 	.fifo_size = 64,
 	.has_dmamode = true,
+	.has_slavemode = true,
+	.disable = mx51_ecspi_disable,
 	.devtype = IMX51_ECSPI,
 };
 
@@ -777,6 +860,8 @@ static struct spi_imx_devtype_data imx53_ecspi_devtype_data = {
 	.reset = mx51_ecspi_reset,
 	.fifo_size = 64,
 	.has_dmamode = true,
+	.has_slavemode = true,
+	.disable = mx51_ecspi_disable,
 	.devtype = IMX53_ECSPI,
 };
 
@@ -839,14 +924,16 @@ static void spi_imx_push(struct spi_imx_data *spi_imx)
 		spi_imx->txfifo++;
 	}
 
-	spi_imx->devtype_data->trigger(spi_imx);
+	if (!spi_imx->slave_mode)
+		spi_imx->devtype_data->trigger(spi_imx);
 }
 
 static irqreturn_t spi_imx_isr(int irq, void *dev_id)
 {
 	struct spi_imx_data *spi_imx = dev_id;
 
-	while (spi_imx->devtype_data->rx_available(spi_imx)) {
+	while (spi_imx->txfifo &&
+	       spi_imx->devtype_data->rx_available(spi_imx)) {
 		spi_imx->rx(spi_imx);
 		spi_imx->txfifo--;
 	}
@@ -957,6 +1044,12 @@ static int spi_imx_setupxfer(struct spi_device *spi,
 			return ret;
 	}
 
+	if (is_imx53_ecspi(spi_imx) && spi_imx->slave_mode) {
+		spi_imx->rx = mx53_ecspi_rx_slave;
+		spi_imx->tx = mx53_ecspi_tx_slave;
+		spi_imx->slave_burst = t->len;
+	}
+
 	spi_imx->devtype_data->config(spi, &config);
 
 	return 0;
@@ -1143,11 +1236,61 @@ static int spi_imx_pio_transfer(struct spi_device *spi,
 	return transfer->len;
 }
 
+static int spi_imx_pio_transfer_slave(struct spi_device *spi,
+				      struct spi_transfer *transfer)
+{
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+	int ret = transfer->len;
+
+	if (is_imx53_ecspi(spi_imx) &&
+	    transfer->len > MX53_MAX_TRANSFER_BYTES) {
+		dev_err(&spi->dev, "Transaction too big, max size is %d bytes\n",
+			MX53_MAX_TRANSFER_BYTES);
+		return -EMSGSIZE;
+	}
+
+	spi_imx->tx_buf = transfer->tx_buf;
+	spi_imx->rx_buf = transfer->rx_buf;
+	spi_imx->count = transfer->len;
+	spi_imx->txfifo = 0;
+
+	reinit_completion(&spi_imx->xfer_done);
+	spi_imx->slave_aborted = false;
+
+	spi_imx_push(spi_imx);
+
+	spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE | MXC_INT_RDR);
+
+	if (wait_for_completion_interruptible(&spi_imx->xfer_done) ||
+	    spi_imx->slave_aborted) {
+		dev_dbg(&spi->dev, "interrupted\n");
+		ret = -EINTR;
+	}
+
+	/* ecspi has a HW issue when works in Slave mode,
+	 * after 64 words writtern to TXFIFO, even TXFIFO becomes empty,
+	 * ECSPI_TXDATA keeps shift out the last word data,
+	 * so we have to disable ECSPI when in slave mode after the
+	 * transfer completes
+	 */
+	if (spi_imx->devtype_data->disable)
+		spi_imx->devtype_data->disable(spi_imx);
+
+	return ret;
+}
+
 static int spi_imx_transfer(struct spi_device *spi,
 				struct spi_transfer *transfer)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
 
+	/* flush rxfifo before transfer */
+	while (spi_imx->devtype_data->rx_available(spi_imx))
+		spi_imx->rx(spi_imx);
+
+	if (spi_imx->slave_mode)
+		return spi_imx_pio_transfer_slave(spi, transfer);
+
 	if (spi_imx->usedma)
 		return spi_imx_dma_transfer(spi_imx, transfer);
 	else
@@ -1201,6 +1344,16 @@ spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg)
 	return 0;
 }
 
+static int spi_imx_slave_abort(struct spi_master *master)
+{
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+
+	spi_imx->slave_aborted = true;
+	complete(&spi_imx->xfer_done);
+
+	return 0;
+}
+
 static int spi_imx_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -1212,13 +1365,24 @@ static int spi_imx_probe(struct platform_device *pdev)
 	struct spi_imx_data *spi_imx;
 	struct resource *res;
 	int i, ret, irq, spi_drctl;
+	const struct spi_imx_devtype_data *devtype_data = of_id ? of_id->data :
+		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
+	bool slave_mode;
 
 	if (!np && !mxc_platform_info) {
 		dev_err(&pdev->dev, "can't get the platform data\n");
 		return -EINVAL;
 	}
 
-	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data));
+	slave_mode = devtype_data->has_slavemode &&
+			of_property_read_bool(np, "spi-slave");
+	if (slave_mode)
+		master = spi_alloc_slave(&pdev->dev,
+					 sizeof(struct spi_imx_data));
+	else
+		master = spi_alloc_master(&pdev->dev,
+					  sizeof(struct spi_imx_data));
+
 	ret = of_property_read_u32(np, "fsl,spi-rdy-drctl", &spi_drctl);
 	if ((ret < 0) || (spi_drctl >= 0x3)) {
 		/* '11' is reserved */
@@ -1236,9 +1400,9 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx = spi_master_get_devdata(master);
 	spi_imx->bitbang.master = master;
 	spi_imx->dev = &pdev->dev;
+	spi_imx->slave_mode = slave_mode;
 
-	spi_imx->devtype_data = of_id ? of_id->data :
-		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
+	spi_imx->devtype_data = devtype_data;
 
 	if (mxc_platform_info) {
 		master->num_chipselect = mxc_platform_info->num_chipselect;
@@ -1258,6 +1422,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
 	spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
 	spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
+	spi_imx->bitbang.master->slave_abort = spi_imx_slave_abort;
 	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
 	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx) ||
 	    is_imx53_ecspi(spi_imx))
@@ -1334,23 +1499,26 @@ static int spi_imx_probe(struct platform_device *pdev)
 		goto out_clk_put;
 	}
 
-	if (!master->cs_gpios) {
-		dev_err(&pdev->dev, "No CS GPIOs available\n");
-		ret = -EINVAL;
-		goto out_clk_put;
-	}
-
-	for (i = 0; i < master->num_chipselect; i++) {
-		if (!gpio_is_valid(master->cs_gpios[i]))
-			continue;
-
-		ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
-					DRIVER_NAME);
-		if (ret) {
-			dev_err(&pdev->dev, "Can't get CS GPIO %i\n",
-				master->cs_gpios[i]);
+	if (!spi_imx->slave_mode) {
+		if (!master->cs_gpios) {
+			dev_err(&pdev->dev, "No CS GPIOs available\n");
+			ret = -EINVAL;
 			goto out_clk_put;
 		}
+
+		for (i = 0; i < master->num_chipselect; i++) {
+			if (!gpio_is_valid(master->cs_gpios[i]))
+				continue;
+
+			ret = devm_gpio_request(&pdev->dev,
+						master->cs_gpios[i],
+						DRIVER_NAME);
+			if (ret) {
+				dev_err(&pdev->dev, "Can't get CS GPIO %i\n",
+					master->cs_gpios[i]);
+				goto out_clk_put;
+			}
+		}
 	}
 
 	dev_info(&pdev->dev, "probed\n");
-- 
2.9.3

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Re: [PATCH linux-next v4 4/4] spi: imx: Add support for SPI Slave mode

[Sascha Hauer]

On Mon, Jun 05, 2017 at 12:38:09PM +0900, Jiada Wang wrote:
> Previously i.MX SPI controller only works in Master mode.
> This patch adds support to i.MX51, i.MX53 and i.MX6 ECSPI
> controller to work also in Slave mode.
> 
> Currently SPI Slave mode support patch has the following limitations:
> 1. The stale data in RXFIFO will be dropped when the Slave does any new
>    transfer.
> 2. One transfer can be finished only after all transfer->len data been
>    transferred to master device
> 3. Slave device only accepts transfer->len data. Any data longer than this
>    from master device will be dropped. Any data shorter than this from
>    master will cause SPI to stuck due to mentioned HW limitation 2.
> 4. Only PIO transfer is supported in Slave mode.
> 
> Following HW limitation applies:
> 1.  ECSPI has a HW issue when works in Slave mode, after 64
>     words written to TXFIFO, even TXFIFO becomes empty,
>     ECSPI_TXDATA keeps shift out the last word data,
>     so we have to disable ECSPI when in slave mode after the
>     transfer completes
> 2.  Due to Freescale errata ERR003775 "eCSPI: Burst completion by Chip
>     Select (SS) signal in Slave mode is not functional" burst size must
>     be set exactly to the size of the transfer. This limit SPI transaction
>     with maximum 2^12 bits. This errata affects i.MX53 and i.MX6 ECSPI
>     controllers.
> 
> Signed-off-by: Jiada Wang <jiada_wang-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
> ---
>  drivers/spi/spi-imx.c | 228 +++++++++++++++++++++++++++++++++++++++++++-------
>  1 file changed, 198 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
> index 5034f89..3db3809 100644
> --- a/drivers/spi/spi-imx.c
> +++ b/drivers/spi/spi-imx.c
> @@ -53,9 +53,13 @@
>  /* generic defines to abstract from the different register layouts */
>  #define MXC_INT_RR	(1 << 0) /* Receive data ready interrupt */
>  #define MXC_INT_TE	(1 << 1) /* Transmit FIFO empty interrupt */
> +#define MXC_INT_RDR	BIT(4) /* Receive date threshold interrupt */
>  
>  /* The maximum  bytes that a sdma BD can transfer.*/
>  #define MAX_SDMA_BD_BYTES  (1 << 15)
> +/* The maximum bytes that IMX53_ECSPI can transfer in slave mode.*/
> +#define MX53_MAX_TRANSFER_BYTES		512
> +
>  struct spi_imx_config {
>  	unsigned int speed_hz;
>  	unsigned int bpw;
> @@ -79,7 +83,9 @@ struct spi_imx_devtype_data {
>  	void (*trigger)(struct spi_imx_data *);
>  	int (*rx_available)(struct spi_imx_data *);
>  	void (*reset)(struct spi_imx_data *);
> +	void (*disable)(struct spi_imx_data *);
>  	bool has_dmamode;
> +	bool has_slavemode;
>  	unsigned int fifo_size;
>  	enum spi_imx_devtype devtype;
>  };
> @@ -107,6 +113,11 @@ struct spi_imx_data {
>  	const void *tx_buf;
>  	unsigned int txfifo; /* number of words pushed in tx FIFO */
>  
> +	/* Slave mode */
> +	bool slave_mode;
> +	bool slave_aborted;
> +	unsigned int slave_burst;
> +
>  	/* DMA */
>  	bool usedma;
>  	u32 wml;
> @@ -223,6 +234,9 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
>  	if (!transfer)
>  		return false;
>  
> +	if (spi_imx->slave_mode)
> +		return false;
> +
>  	bpw = transfer->bits_per_word;
>  	if (!bpw)
>  		bpw = spi->bits_per_word;
> @@ -266,6 +280,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
>  #define MX51_ECSPI_INT		0x10
>  #define MX51_ECSPI_INT_TEEN		(1 <<  0)
>  #define MX51_ECSPI_INT_RREN		(1 <<  3)
> +#define MX51_ECSPI_INT_RDREN		(1 <<  4)
>  
>  #define MX51_ECSPI_DMA      0x14
>  #define MX51_ECSPI_DMA_TX_WML(wml)	((wml) & 0x3f)
> @@ -282,6 +297,46 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
>  #define MX51_ECSPI_TESTREG	0x20
>  #define MX51_ECSPI_TESTREG_LBC	BIT(31)
>  
> +static void mx53_ecspi_rx_slave(struct spi_imx_data *spi_imx)
> +{
> +	u32 val = be32_to_cpu(readl(spi_imx->base + MXC_CSPIRXDATA));
> +
> +	if (spi_imx->rx_buf) {
> +		int n_bytes = spi_imx->slave_burst % sizeof(val);
> +
> +		if (n_bytes) {
> +			memcpy(spi_imx->rx_buf,
> +			       ((u8 *)&val) + sizeof(val) - n_bytes, n_bytes);
> +		} else {
> +			*((u32 *)spi_imx->rx_buf) = val;
> +			n_bytes = sizeof(val);
> +		}
> +
> +		spi_imx->rx_buf += n_bytes;
> +		spi_imx->slave_burst -= n_bytes;
> +	}
> +}

You can do the same optimization you have done for mx53_ecspi_tx_slave()
for mx53_ecspi_rx_slave() aswell.

Otherwise the patch looks fine to me now.

Sascha


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Re: [PATCH linux-next v4 4/4] spi: imx: Add support for SPI Slave mode

[Jiada Wang]

Hi Sascha

On 06/07/2017 01:41 AM, Sascha Hauer wrote:
> On Mon, Jun 05, 2017 at 12:38:09PM +0900, Jiada Wang wrote:
>> Previously i.MX SPI controller only works in Master mode.
>> This patch adds support to i.MX51, i.MX53 and i.MX6 ECSPI
>> controller to work also in Slave mode.
>>
>> Currently SPI Slave mode support patch has the following limitations:
>> 1. The stale data in RXFIFO will be dropped when the Slave does any new
>>     transfer.
>> 2. One transfer can be finished only after all transfer->len data been
>>     transferred to master device
>> 3. Slave device only accepts transfer->len data. Any data longer than this
>>     from master device will be dropped. Any data shorter than this from
>>     master will cause SPI to stuck due to mentioned HW limitation 2.
>> 4. Only PIO transfer is supported in Slave mode.
>>
>> Following HW limitation applies:
>> 1.  ECSPI has a HW issue when works in Slave mode, after 64
>>      words written to TXFIFO, even TXFIFO becomes empty,
>>      ECSPI_TXDATA keeps shift out the last word data,
>>      so we have to disable ECSPI when in slave mode after the
>>      transfer completes
>> 2.  Due to Freescale errata ERR003775 "eCSPI: Burst completion by Chip
>>      Select (SS) signal in Slave mode is not functional" burst size must
>>      be set exactly to the size of the transfer. This limit SPI transaction
>>      with maximum 2^12 bits. This errata affects i.MX53 and i.MX6 ECSPI
>>      controllers.
>>
>> Signed-off-by: Jiada Wang<jiada_wang-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
>> ---
>>   drivers/spi/spi-imx.c | 228 +++++++++++++++++++++++++++++++++++++++++++-------
>>   1 file changed, 198 insertions(+), 30 deletions(-)
>>
>> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
>> index 5034f89..3db3809 100644
>> --- a/drivers/spi/spi-imx.c
>> +++ b/drivers/spi/spi-imx.c
>> @@ -53,9 +53,13 @@
>>   /* generic defines to abstract from the different register layouts */
>>   #define MXC_INT_RR	(1<<  0) /* Receive data ready interrupt */
>>   #define MXC_INT_TE	(1<<  1) /* Transmit FIFO empty interrupt */
>> +#define MXC_INT_RDR	BIT(4) /* Receive date threshold interrupt */
>>
>>   /* The maximum  bytes that a sdma BD can transfer.*/
>>   #define MAX_SDMA_BD_BYTES  (1<<  15)
>> +/* The maximum bytes that IMX53_ECSPI can transfer in slave mode.*/
>> +#define MX53_MAX_TRANSFER_BYTES		512
>> +
>>   struct spi_imx_config {
>>   	unsigned int speed_hz;
>>   	unsigned int bpw;
>> @@ -79,7 +83,9 @@ struct spi_imx_devtype_data {
>>   	void (*trigger)(struct spi_imx_data *);
>>   	int (*rx_available)(struct spi_imx_data *);
>>   	void (*reset)(struct spi_imx_data *);
>> +	void (*disable)(struct spi_imx_data *);
>>   	bool has_dmamode;
>> +	bool has_slavemode;
>>   	unsigned int fifo_size;
>>   	enum spi_imx_devtype devtype;
>>   };
>> @@ -107,6 +113,11 @@ struct spi_imx_data {
>>   	const void *tx_buf;
>>   	unsigned int txfifo; /* number of words pushed in tx FIFO */
>>
>> +	/* Slave mode */
>> +	bool slave_mode;
>> +	bool slave_aborted;
>> +	unsigned int slave_burst;
>> +
>>   	/* DMA */
>>   	bool usedma;
>>   	u32 wml;
>> @@ -223,6 +234,9 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
>>   	if (!transfer)
>>   		return false;
>>
>> +	if (spi_imx->slave_mode)
>> +		return false;
>> +
>>   	bpw = transfer->bits_per_word;
>>   	if (!bpw)
>>   		bpw = spi->bits_per_word;
>> @@ -266,6 +280,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
>>   #define MX51_ECSPI_INT		0x10
>>   #define MX51_ECSPI_INT_TEEN		(1<<   0)
>>   #define MX51_ECSPI_INT_RREN		(1<<   3)
>> +#define MX51_ECSPI_INT_RDREN		(1<<   4)
>>
>>   #define MX51_ECSPI_DMA      0x14
>>   #define MX51_ECSPI_DMA_TX_WML(wml)	((wml)&  0x3f)
>> @@ -282,6 +297,46 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
>>   #define MX51_ECSPI_TESTREG	0x20
>>   #define MX51_ECSPI_TESTREG_LBC	BIT(31)
>>
>> +static void mx53_ecspi_rx_slave(struct spi_imx_data *spi_imx)
>> +{
>> +	u32 val = be32_to_cpu(readl(spi_imx->base + MXC_CSPIRXDATA));
>> +
>> +	if (spi_imx->rx_buf) {
>> +		int n_bytes = spi_imx->slave_burst % sizeof(val);
>> +
>> +		if (n_bytes) {
>> +			memcpy(spi_imx->rx_buf,
>> +			       ((u8 *)&val) + sizeof(val) - n_bytes, n_bytes);
>> +		} else {
>> +			*((u32 *)spi_imx->rx_buf) = val;
>> +			n_bytes = sizeof(val);
>> +		}
>> +
>> +		spi_imx->rx_buf += n_bytes;
>> +		spi_imx->slave_burst -= n_bytes;
>> +	}
>> +}
> You can do the same optimization you have done for mx53_ecspi_tx_slave()
> for mx53_ecspi_rx_slave() aswell.
>
> Otherwise the patch looks fine to me now.
I will submit updated patch set after rebase to have your latest change
to spi-imx.

Thanks,
Jiada

>
> Sascha
>
>

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