2016-11-08 16:47:57

by Nicolas Ferre

[permalink] [raw]
Subject: [PATCH v2] spi: atmel: use managed resource for gpio chip select

Use the managed gpio CS pin request so that we avoid having trouble
in the cleanup code.
In fact, if module was configured with DT, cleanup code released
invalid pin. Since resource wasn't freed, module cannot be reinserted.

This require to extract the gpio request call from the "setup" function
and call it in the appropriate probe function.

Reported-by: Alexander Morozov <[email protected]>
Signed-off-by: Nicolas Ferre <[email protected]>
---
v2: fix devm_gpio_request location: the setup code for device was not proper
location. Move it to the probe function and add needed DT routines to
handle all CS gpio specified.

drivers/spi/spi-atmel.c | 50 ++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 39 insertions(+), 11 deletions(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 32683a13dd60..a60925614480 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -24,6 +24,7 @@

#include <linux/io.h>
#include <linux/gpio.h>
+#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm_runtime.h>

@@ -1204,7 +1205,6 @@ static int atmel_spi_setup(struct spi_device *spi)
u32 csr;
unsigned int bits = spi->bits_per_word;
unsigned int npcs_pin;
- int ret;

as = spi_master_get_devdata(spi->master);

@@ -1247,16 +1247,9 @@ static int atmel_spi_setup(struct spi_device *spi)
if (!asd)
return -ENOMEM;

- if (as->use_cs_gpios) {
- ret = gpio_request(npcs_pin, dev_name(&spi->dev));
- if (ret) {
- kfree(asd);
- return ret;
- }
-
+ if (as->use_cs_gpios)
gpio_direction_output(npcs_pin,
!(spi->mode & SPI_CS_HIGH));
- }

asd->npcs_pin = npcs_pin;
spi->controller_state = asd;
@@ -1471,13 +1464,11 @@ static int atmel_spi_transfer_one_message(struct spi_master *master,
static void atmel_spi_cleanup(struct spi_device *spi)
{
struct atmel_spi_device *asd = spi->controller_state;
- unsigned gpio = (unsigned long) spi->controller_data;

if (!asd)
return;

spi->controller_state = NULL;
- gpio_free(gpio);
kfree(asd);
}

@@ -1499,6 +1490,39 @@ static void atmel_get_caps(struct atmel_spi *as)
}

/*-------------------------------------------------------------------------*/
+static int atmel_spi_gpio_cs(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ struct device_node *np = master->dev.of_node;
+ int i;
+ int ret = 0;
+ int nb = 0;
+
+ if (!as->use_cs_gpios)
+ return 0;
+
+ if (!np)
+ return 0;
+
+ nb = of_gpio_named_count(np, "cs-gpios");
+ for (i = 0; i < nb; i++) {
+ int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
+ "cs-gpios", i);
+
+ if (cs_gpio == -EPROBE_DEFER)
+ return cs_gpio;
+
+ if (gpio_is_valid(cs_gpio)) {
+ ret = devm_gpio_request(&pdev->dev, cs_gpio,
+ dev_name(&pdev->dev));
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}

static int atmel_spi_probe(struct platform_device *pdev)
{
@@ -1577,6 +1601,10 @@ static int atmel_spi_probe(struct platform_device *pdev)
master->num_chipselect = 4;
}

+ ret = atmel_spi_gpio_cs(pdev);
+ if (ret)
+ goto out_unmap_regs;
+
as->use_dma = false;
as->use_pdc = false;
if (as->caps.has_dma_support) {
--
2.9.0


2016-11-08 17:57:08

by Alexandre Belloni

[permalink] [raw]
Subject: Re: [PATCH v2] spi: atmel: use managed resource for gpio chip select

On 08/11/2016 at 18:48:52 +0100, Nicolas Ferre wrote :
> Use the managed gpio CS pin request so that we avoid having trouble
> in the cleanup code.
> In fact, if module was configured with DT, cleanup code released
> invalid pin. Since resource wasn't freed, module cannot be reinserted.
>
> This require to extract the gpio request call from the "setup" function
> and call it in the appropriate probe function.
>
> Reported-by: Alexander Morozov <[email protected]>
> Signed-off-by: Nicolas Ferre <[email protected]>

I think that's fine but I still have that item on my todo list
(discussion in july 2014 with Mark):

---
>> Mark: maybe it would make sense to do devm_gpio_request_one() in
>> of_spi_register_master(), after of_get_named_gpio.

> You need to transition all the drivers doing things manually but yes.
> As I keep saying all the GPIO handling needs to be completely
> refactored.
---

> ---
> v2: fix devm_gpio_request location: the setup code for device was not proper
> location. Move it to the probe function and add needed DT routines to
> handle all CS gpio specified.
>
> drivers/spi/spi-atmel.c | 50 ++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 39 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
> index 32683a13dd60..a60925614480 100644
> --- a/drivers/spi/spi-atmel.c
> +++ b/drivers/spi/spi-atmel.c
> @@ -24,6 +24,7 @@
>
> #include <linux/io.h>
> #include <linux/gpio.h>
> +#include <linux/of_gpio.h>
> #include <linux/pinctrl/consumer.h>
> #include <linux/pm_runtime.h>
>
> @@ -1204,7 +1205,6 @@ static int atmel_spi_setup(struct spi_device *spi)
> u32 csr;
> unsigned int bits = spi->bits_per_word;
> unsigned int npcs_pin;
> - int ret;
>
> as = spi_master_get_devdata(spi->master);
>
> @@ -1247,16 +1247,9 @@ static int atmel_spi_setup(struct spi_device *spi)
> if (!asd)
> return -ENOMEM;
>
> - if (as->use_cs_gpios) {
> - ret = gpio_request(npcs_pin, dev_name(&spi->dev));
> - if (ret) {
> - kfree(asd);
> - return ret;
> - }
> -
> + if (as->use_cs_gpios)
> gpio_direction_output(npcs_pin,
> !(spi->mode & SPI_CS_HIGH));
> - }
>
> asd->npcs_pin = npcs_pin;
> spi->controller_state = asd;
> @@ -1471,13 +1464,11 @@ static int atmel_spi_transfer_one_message(struct spi_master *master,
> static void atmel_spi_cleanup(struct spi_device *spi)
> {
> struct atmel_spi_device *asd = spi->controller_state;
> - unsigned gpio = (unsigned long) spi->controller_data;
>
> if (!asd)
> return;
>
> spi->controller_state = NULL;
> - gpio_free(gpio);
> kfree(asd);
> }
>
> @@ -1499,6 +1490,39 @@ static void atmel_get_caps(struct atmel_spi *as)
> }
>
> /*-------------------------------------------------------------------------*/
> +static int atmel_spi_gpio_cs(struct platform_device *pdev)
> +{
> + struct spi_master *master = platform_get_drvdata(pdev);
> + struct atmel_spi *as = spi_master_get_devdata(master);
> + struct device_node *np = master->dev.of_node;
> + int i;
> + int ret = 0;
> + int nb = 0;
> +
> + if (!as->use_cs_gpios)
> + return 0;
> +
> + if (!np)
> + return 0;
> +
> + nb = of_gpio_named_count(np, "cs-gpios");
> + for (i = 0; i < nb; i++) {
> + int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
> + "cs-gpios", i);
> +
> + if (cs_gpio == -EPROBE_DEFER)
> + return cs_gpio;
> +
> + if (gpio_is_valid(cs_gpio)) {
> + ret = devm_gpio_request(&pdev->dev, cs_gpio,
> + dev_name(&pdev->dev));
> + if (ret)
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
>
> static int atmel_spi_probe(struct platform_device *pdev)
> {
> @@ -1577,6 +1601,10 @@ static int atmel_spi_probe(struct platform_device *pdev)
> master->num_chipselect = 4;
> }
>
> + ret = atmel_spi_gpio_cs(pdev);
> + if (ret)
> + goto out_unmap_regs;
> +
> as->use_dma = false;
> as->use_pdc = false;
> if (as->caps.has_dma_support) {
> --
> 2.9.0
>

--
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

2016-11-09 09:17:09

by Nicolas Ferre

[permalink] [raw]
Subject: Re: [PATCH v2] spi: atmel: use managed resource for gpio chip select

Le 08/11/2016 ? 18:49, Alexandre Belloni a ?crit :
> On 08/11/2016 at 18:48:52 +0100, Nicolas Ferre wrote :
>> Use the managed gpio CS pin request so that we avoid having trouble
>> in the cleanup code.
>> In fact, if module was configured with DT, cleanup code released
>> invalid pin. Since resource wasn't freed, module cannot be reinserted.
>>
>> This require to extract the gpio request call from the "setup" function
>> and call it in the appropriate probe function.
>>
>> Reported-by: Alexander Morozov <[email protected]>
>> Signed-off-by: Nicolas Ferre <[email protected]>
>
> I think that's fine but I still have that item on my todo list
> (discussion in july 2014 with Mark):
>
> ---
>>> Mark: maybe it would make sense to do devm_gpio_request_one() in
>>> of_spi_register_master(), after of_get_named_gpio.
>
>> You need to transition all the drivers doing things manually but yes.
>> As I keep saying all the GPIO handling needs to be completely
>> refactored.
> ---

Would make sense indeed as we are currently doing the same node scanning
twice...

But this patch actually fixes an issue with module unloading/re-loading
and freeing of a wrong gpio. So I do think that we shouldn't hold its
adoption while thinking about this enhancement...

Regards,

>> ---
>> v2: fix devm_gpio_request location: the setup code for device was not proper
>> location. Move it to the probe function and add needed DT routines to
>> handle all CS gpio specified.
>>
>> drivers/spi/spi-atmel.c | 50 ++++++++++++++++++++++++++++++++++++++-----------
>> 1 file changed, 39 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
>> index 32683a13dd60..a60925614480 100644
>> --- a/drivers/spi/spi-atmel.c
>> +++ b/drivers/spi/spi-atmel.c
>> @@ -24,6 +24,7 @@
>>
>> #include <linux/io.h>
>> #include <linux/gpio.h>
>> +#include <linux/of_gpio.h>
>> #include <linux/pinctrl/consumer.h>
>> #include <linux/pm_runtime.h>
>>
>> @@ -1204,7 +1205,6 @@ static int atmel_spi_setup(struct spi_device *spi)
>> u32 csr;
>> unsigned int bits = spi->bits_per_word;
>> unsigned int npcs_pin;
>> - int ret;
>>
>> as = spi_master_get_devdata(spi->master);
>>
>> @@ -1247,16 +1247,9 @@ static int atmel_spi_setup(struct spi_device *spi)
>> if (!asd)
>> return -ENOMEM;
>>
>> - if (as->use_cs_gpios) {
>> - ret = gpio_request(npcs_pin, dev_name(&spi->dev));
>> - if (ret) {
>> - kfree(asd);
>> - return ret;
>> - }
>> -
>> + if (as->use_cs_gpios)
>> gpio_direction_output(npcs_pin,
>> !(spi->mode & SPI_CS_HIGH));
>> - }
>>
>> asd->npcs_pin = npcs_pin;
>> spi->controller_state = asd;
>> @@ -1471,13 +1464,11 @@ static int atmel_spi_transfer_one_message(struct spi_master *master,
>> static void atmel_spi_cleanup(struct spi_device *spi)
>> {
>> struct atmel_spi_device *asd = spi->controller_state;
>> - unsigned gpio = (unsigned long) spi->controller_data;
>>
>> if (!asd)
>> return;
>>
>> spi->controller_state = NULL;
>> - gpio_free(gpio);
>> kfree(asd);
>> }
>>
>> @@ -1499,6 +1490,39 @@ static void atmel_get_caps(struct atmel_spi *as)
>> }
>>
>> /*-------------------------------------------------------------------------*/
>> +static int atmel_spi_gpio_cs(struct platform_device *pdev)
>> +{
>> + struct spi_master *master = platform_get_drvdata(pdev);
>> + struct atmel_spi *as = spi_master_get_devdata(master);
>> + struct device_node *np = master->dev.of_node;
>> + int i;
>> + int ret = 0;
>> + int nb = 0;
>> +
>> + if (!as->use_cs_gpios)
>> + return 0;
>> +
>> + if (!np)
>> + return 0;
>> +
>> + nb = of_gpio_named_count(np, "cs-gpios");
>> + for (i = 0; i < nb; i++) {
>> + int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
>> + "cs-gpios", i);
>> +
>> + if (cs_gpio == -EPROBE_DEFER)
>> + return cs_gpio;
>> +
>> + if (gpio_is_valid(cs_gpio)) {
>> + ret = devm_gpio_request(&pdev->dev, cs_gpio,
>> + dev_name(&pdev->dev));
>> + if (ret)
>> + return ret;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>>
>> static int atmel_spi_probe(struct platform_device *pdev)
>> {
>> @@ -1577,6 +1601,10 @@ static int atmel_spi_probe(struct platform_device *pdev)
>> master->num_chipselect = 4;
>> }
>>
>> + ret = atmel_spi_gpio_cs(pdev);
>> + if (ret)
>> + goto out_unmap_regs;
>> +
>> as->use_dma = false;
>> as->use_pdc = false;
>> if (as->caps.has_dma_support) {
>> --
>> 2.9.0
>>
>


--
Nicolas Ferre

2016-11-09 09:42:08

by Alexandre Belloni

[permalink] [raw]
Subject: Re: [PATCH v2] spi: atmel: use managed resource for gpio chip select

On 09/11/2016 at 10:16:18 +0100, Nicolas Ferre wrote :
> Le 08/11/2016 ? 18:49, Alexandre Belloni a ?crit :
> > On 08/11/2016 at 18:48:52 +0100, Nicolas Ferre wrote :
> >> Use the managed gpio CS pin request so that we avoid having trouble
> >> in the cleanup code.
> >> In fact, if module was configured with DT, cleanup code released
> >> invalid pin. Since resource wasn't freed, module cannot be reinserted.
> >>
> >> This require to extract the gpio request call from the "setup" function
> >> and call it in the appropriate probe function.
> >>
> >> Reported-by: Alexander Morozov <[email protected]>
> >> Signed-off-by: Nicolas Ferre <[email protected]>
> >
> > I think that's fine but I still have that item on my todo list
> > (discussion in july 2014 with Mark):
> >
> > ---
> >>> Mark: maybe it would make sense to do devm_gpio_request_one() in
> >>> of_spi_register_master(), after of_get_named_gpio.
> >
> >> You need to transition all the drivers doing things manually but yes.
> >> As I keep saying all the GPIO handling needs to be completely
> >> refactored.
> > ---
>
> Would make sense indeed as we are currently doing the same node scanning
> twice...
>
> But this patch actually fixes an issue with module unloading/re-loading
> and freeing of a wrong gpio. So I do think that we shouldn't hold its
> adoption while thinking about this enhancement...
>

Yes, this patch is still useful as-is and fixes a bug.

> Regards,
>
> >> ---
> >> v2: fix devm_gpio_request location: the setup code for device was not proper
> >> location. Move it to the probe function and add needed DT routines to
> >> handle all CS gpio specified.
> >>
> >> drivers/spi/spi-atmel.c | 50 ++++++++++++++++++++++++++++++++++++++-----------
> >> 1 file changed, 39 insertions(+), 11 deletions(-)
> >>
> >> diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
> >> index 32683a13dd60..a60925614480 100644
> >> --- a/drivers/spi/spi-atmel.c
> >> +++ b/drivers/spi/spi-atmel.c
> >> @@ -24,6 +24,7 @@
> >>
> >> #include <linux/io.h>
> >> #include <linux/gpio.h>
> >> +#include <linux/of_gpio.h>
> >> #include <linux/pinctrl/consumer.h>
> >> #include <linux/pm_runtime.h>
> >>
> >> @@ -1204,7 +1205,6 @@ static int atmel_spi_setup(struct spi_device *spi)
> >> u32 csr;
> >> unsigned int bits = spi->bits_per_word;
> >> unsigned int npcs_pin;
> >> - int ret;
> >>
> >> as = spi_master_get_devdata(spi->master);
> >>
> >> @@ -1247,16 +1247,9 @@ static int atmel_spi_setup(struct spi_device *spi)
> >> if (!asd)
> >> return -ENOMEM;
> >>
> >> - if (as->use_cs_gpios) {
> >> - ret = gpio_request(npcs_pin, dev_name(&spi->dev));
> >> - if (ret) {
> >> - kfree(asd);
> >> - return ret;
> >> - }
> >> -
> >> + if (as->use_cs_gpios)
> >> gpio_direction_output(npcs_pin,
> >> !(spi->mode & SPI_CS_HIGH));
> >> - }
> >>
> >> asd->npcs_pin = npcs_pin;
> >> spi->controller_state = asd;
> >> @@ -1471,13 +1464,11 @@ static int atmel_spi_transfer_one_message(struct spi_master *master,
> >> static void atmel_spi_cleanup(struct spi_device *spi)
> >> {
> >> struct atmel_spi_device *asd = spi->controller_state;
> >> - unsigned gpio = (unsigned long) spi->controller_data;
> >>
> >> if (!asd)
> >> return;
> >>
> >> spi->controller_state = NULL;
> >> - gpio_free(gpio);
> >> kfree(asd);
> >> }
> >>
> >> @@ -1499,6 +1490,39 @@ static void atmel_get_caps(struct atmel_spi *as)
> >> }
> >>
> >> /*-------------------------------------------------------------------------*/
> >> +static int atmel_spi_gpio_cs(struct platform_device *pdev)
> >> +{
> >> + struct spi_master *master = platform_get_drvdata(pdev);
> >> + struct atmel_spi *as = spi_master_get_devdata(master);
> >> + struct device_node *np = master->dev.of_node;
> >> + int i;
> >> + int ret = 0;
> >> + int nb = 0;
> >> +
> >> + if (!as->use_cs_gpios)
> >> + return 0;
> >> +
> >> + if (!np)
> >> + return 0;
> >> +
> >> + nb = of_gpio_named_count(np, "cs-gpios");
> >> + for (i = 0; i < nb; i++) {
> >> + int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
> >> + "cs-gpios", i);
> >> +
> >> + if (cs_gpio == -EPROBE_DEFER)
> >> + return cs_gpio;
> >> +
> >> + if (gpio_is_valid(cs_gpio)) {
> >> + ret = devm_gpio_request(&pdev->dev, cs_gpio,
> >> + dev_name(&pdev->dev));
> >> + if (ret)
> >> + return ret;
> >> + }
> >> + }
> >> +
> >> + return 0;
> >> +}
> >>
> >> static int atmel_spi_probe(struct platform_device *pdev)
> >> {
> >> @@ -1577,6 +1601,10 @@ static int atmel_spi_probe(struct platform_device *pdev)
> >> master->num_chipselect = 4;
> >> }
> >>
> >> + ret = atmel_spi_gpio_cs(pdev);
> >> + if (ret)
> >> + goto out_unmap_regs;
> >> +
> >> as->use_dma = false;
> >> as->use_pdc = false;
> >> if (as->caps.has_dma_support) {
> >> --
> >> 2.9.0
> >>
> >
>
>
> --
> Nicolas Ferre

--
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

2016-11-09 15:01:43

by Mark Brown

[permalink] [raw]
Subject: Applied "spi: atmel: use managed resource for gpio chip select" to the spi tree

The patch

spi: atmel: use managed resource for gpio chip select

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 9610620078a3900e7fad82de620ce809fd29ba60 Mon Sep 17 00:00:00 2001
From: Nicolas Ferre <[email protected]>
Date: Tue, 8 Nov 2016 18:48:52 +0100
Subject: [PATCH] spi: atmel: use managed resource for gpio chip select

Use the managed gpio CS pin request so that we avoid having trouble
in the cleanup code.
In fact, if module was configured with DT, cleanup code released
invalid pin. Since resource wasn't freed, module cannot be reinserted.

This require to extract the gpio request call from the "setup" function
and call it in the appropriate probe function.

Reported-by: Alexander Morozov <[email protected]>
Signed-off-by: Nicolas Ferre <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
---
drivers/spi/spi-atmel.c | 50 ++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 39 insertions(+), 11 deletions(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 8feac599e9ab..d3affa6afe7e 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -24,6 +24,7 @@

#include <linux/io.h>
#include <linux/gpio.h>
+#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm_runtime.h>

@@ -1204,7 +1205,6 @@ static int atmel_spi_setup(struct spi_device *spi)
u32 csr;
unsigned int bits = spi->bits_per_word;
unsigned int npcs_pin;
- int ret;

as = spi_master_get_devdata(spi->master);

@@ -1247,16 +1247,9 @@ static int atmel_spi_setup(struct spi_device *spi)
if (!asd)
return -ENOMEM;

- if (as->use_cs_gpios) {
- ret = gpio_request(npcs_pin, dev_name(&spi->dev));
- if (ret) {
- kfree(asd);
- return ret;
- }
-
+ if (as->use_cs_gpios)
gpio_direction_output(npcs_pin,
!(spi->mode & SPI_CS_HIGH));
- }

asd->npcs_pin = npcs_pin;
spi->controller_state = asd;
@@ -1471,13 +1464,11 @@ static int atmel_spi_transfer_one_message(struct spi_master *master,
static void atmel_spi_cleanup(struct spi_device *spi)
{
struct atmel_spi_device *asd = spi->controller_state;
- unsigned gpio = (unsigned long) spi->controller_data;

if (!asd)
return;

spi->controller_state = NULL;
- gpio_free(gpio);
kfree(asd);
}

@@ -1499,6 +1490,39 @@ static void atmel_get_caps(struct atmel_spi *as)
}

/*-------------------------------------------------------------------------*/
+static int atmel_spi_gpio_cs(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ struct device_node *np = master->dev.of_node;
+ int i;
+ int ret = 0;
+ int nb = 0;
+
+ if (!as->use_cs_gpios)
+ return 0;
+
+ if (!np)
+ return 0;
+
+ nb = of_gpio_named_count(np, "cs-gpios");
+ for (i = 0; i < nb; i++) {
+ int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
+ "cs-gpios", i);
+
+ if (cs_gpio == -EPROBE_DEFER)
+ return cs_gpio;
+
+ if (gpio_is_valid(cs_gpio)) {
+ ret = devm_gpio_request(&pdev->dev, cs_gpio,
+ dev_name(&pdev->dev));
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}

static int atmel_spi_probe(struct platform_device *pdev)
{
@@ -1577,6 +1601,10 @@ static int atmel_spi_probe(struct platform_device *pdev)
master->num_chipselect = 4;
}

+ ret = atmel_spi_gpio_cs(pdev);
+ if (ret)
+ goto out_unmap_regs;
+
as->use_dma = false;
as->use_pdc = false;
if (as->caps.has_dma_support) {
--
2.10.2