[2/2] spi: atmel: add PM support to SAMA5D2

Message ID 20170412070520.29621-2-quentin.schulz@free-electrons.com
State New
Headers show
Series
  • [1/2] spi: atmel: factorize reusable code for SPI controller init
Related show

Commit Message

Quentin Schulz April 12, 2017, 7:05 a.m.
This adds PM support to the ATMEL SAMA5D2 Xplained.

When suspending, VDDCore is shut down and the SPI registers are lost.
Thus, the SPI controller needs to be re-initialized after resuming from
a system suspend.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>

---
 drivers/spi/spi-atmel.c | 9 +++++++++
 1 file changed, 9 insertions(+)

-- 
2.9.3

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

Comments

Nicolas Ferre April 12, 2017, 9:08 a.m. | #1
Le 12/04/2017 à 09:05, Quentin Schulz a écrit :
> This adds PM support to the ATMEL SAMA5D2 Xplained.


Well not only for this board. The Backup+Self-Refresh PM state is
available for all boards using the SAMA5D2 SoC (and beyond)...

> When suspending, VDDCore is shut down and the SPI registers are lost.


Yes, but only on sama5d2 and only if the Backup+Self-Refresh (or deepest
PM state on sama5d2).

> Thus, the SPI controller needs to be re-initialized after resuming from

> a system suspend.

> 

> Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>


I'm okay with the core of the patch but would prefer a modified commit
message.

Best regards,

> ---

>  drivers/spi/spi-atmel.c | 9 +++++++++

>  1 file changed, 9 insertions(+)

> 

> diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c

> index 247d920..1eb83c9 100644

> --- a/drivers/spi/spi-atmel.c

> +++ b/drivers/spi/spi-atmel.c

> @@ -1702,8 +1702,17 @@ static int atmel_spi_suspend(struct device *dev)

>  static int atmel_spi_resume(struct device *dev)

>  {

>  	struct spi_master *master = dev_get_drvdata(dev);

> +	struct atmel_spi *as = spi_master_get_devdata(master);

>  	int ret;

>  

> +	ret = clk_prepare_enable(as->clk);

> +	if (ret)

> +		return ret;

> +

> +	atmel_spi_init(as);

> +

> +	clk_disable_unprepare(as->clk);

> +

>  	if (!pm_runtime_suspended(dev)) {

>  		ret = atmel_spi_runtime_resume(dev);

>  		if (ret)

> 



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

Patch hide | download patch | download mbox

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 247d920..1eb83c9 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -1702,8 +1702,17 @@  static int atmel_spi_suspend(struct device *dev)
 static int atmel_spi_resume(struct device *dev)
 {
 	struct spi_master *master = dev_get_drvdata(dev);
+	struct atmel_spi *as = spi_master_get_devdata(master);
 	int ret;
 
+	ret = clk_prepare_enable(as->clk);
+	if (ret)
+		return ret;
+
+	atmel_spi_init(as);
+
+	clk_disable_unprepare(as->clk);
+
 	if (!pm_runtime_suspended(dev)) {
 		ret = atmel_spi_runtime_resume(dev);
 		if (ret)