diff mbox

[2/5] mmc: pwrseq_simple: Extend to support more pins

Message ID 1422439819-29854-3-git-send-email-javier.martinez@collabora.co.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Javier Martinez Canillas Jan. 28, 2015, 10:10 a.m. UTC
Many WLAN attached to a SDIO/MMC interface, needs more than one pin for
their reset sequence. For example, is very common for chips to have two
pins: one for reset and one for power enable.

This patch adds support for more reset pins to the pwrseq_simple driver
and instead hardcoding a fixed number, it uses the of_gpio_named_count()
since the MMC power sequence is only built when CONFIG_OF is enabled.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
---
 drivers/mmc/core/pwrseq_simple.c | 54 ++++++++++++++++++++++++++++++----------
 1 file changed, 41 insertions(+), 13 deletions(-)

Comments

Srinivas Kandagatla Jan. 28, 2015, 2:01 p.m. UTC | #1
Hi Javier,

You are in a lead of 3 hrs from me..
Surprisingly I send very much same patch just few Mins ago :-)
May be we can merge goods in both :-)

On 28/01/15 10:10, Javier Martinez Canillas wrote:
> Many WLAN attached to a SDIO/MMC interface, needs more than one pin for
> their reset sequence. For example, is very common for chips to have two
> pins: one for reset and one for power enable.
>
> This patch adds support for more reset pins to the pwrseq_simple driver
> and instead hardcoding a fixed number, it uses the of_gpio_named_count()
> since the MMC power sequence is only built when CONFIG_OF is enabled.
>
> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
> ---
>   drivers/mmc/core/pwrseq_simple.c | 54 ++++++++++++++++++++++++++++++----------
>   1 file changed, 41 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
> index 0958c696137f..9e51fe1051c5 100644
> --- a/drivers/mmc/core/pwrseq_simple.c
> +++ b/drivers/mmc/core/pwrseq_simple.c
> @@ -11,6 +11,7 @@
>   #include <linux/slab.h>
>   #include <linux/device.h>
>   #include <linux/err.h>
> +#include <linux/of_gpio.h>
>   #include <linux/gpio/consumer.h>
>
>   #include <linux/mmc/host.h>
> @@ -19,34 +20,44 @@
>
>   struct mmc_pwrseq_simple {
>   	struct mmc_pwrseq pwrseq;
> -	struct gpio_desc *reset_gpio;
> +	struct gpio_desc **reset_gpio;

May be renaming it to reset_gpios makes more sense..

If you make this struct gpio_desc *reset_gpios[0]; You can aviod an 
extra kmalloc and free ..


> +	int nr_gpios;
>   };
>
>   static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
>   {

[...
>   	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
>   					struct mmc_pwrseq_simple, pwrseq);
> +	int i;
>
> -	if (!IS_ERR(pwrseq->reset_gpio))
> -		gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);
> +	for (i = 0; i < pwrseq->nr_gpios; i++)
> +		if (!IS_ERR(pwrseq->reset_gpio[i]))
> +			gpiod_set_value_cansleep(pwrseq->reset_gpio[i], 1);

...]

>   }
>
>   static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
>   {

[...

>   	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
>   					struct mmc_pwrseq_simple, pwrseq);
> +	int i;
>
> -	if (!IS_ERR(pwrseq->reset_gpio))
> -		gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);
> +	for (i = 0; i < pwrseq->nr_gpios; i++)
> +		if (!IS_ERR(pwrseq->reset_gpio[i]))
> +			gpiod_set_value_cansleep(pwrseq->reset_gpio[i], 0);
...]

Now that we have more code in mmc_pwrseq_simple_post_power_on() and 
mmc_pwrseq_simple_pre_power_on(), Just move most of them into a common 
function like:

static void __mmc_pwrseq_simple_power_on_off(struct mmc_host *host,
						      bool on)
{
	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
					struct mmc_pwrseq_simple, pwrseq);
	int i;

	if (!IS_ERR(pwrseq->reset_gpios)) {
		for (i = 0; i < pwrseq->ngpios; i++)
			gpiod_set_value_cansleep(pwrseq->reset_gpios[i],
						 on ? : 0);
	}
}

static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
{
	__mmc_pwrseq_simple_power_on_off(host, true);
}

static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
{
	__mmc_pwrseq_simple_power_on_off(host, false);
}


>   }
>
>   static void mmc_pwrseq_simple_free(struct mmc_host *host)
>   {
>   	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
>   					struct mmc_pwrseq_simple, pwrseq);
> +	int i;
>
> -	if (!IS_ERR(pwrseq->reset_gpio))
> -		gpiod_put(pwrseq->reset_gpio);
> +	if (pwrseq->nr_gpios > 0) {
> +		for (i = 0; i < pwrseq->nr_gpios; i++)
> +			if (!IS_ERR(pwrseq->reset_gpio[i]))
> +				gpiod_put(pwrseq->reset_gpio[i]);
> +		kfree(pwrseq->reset_gpio);
> +	}
>
>   	kfree(pwrseq);
>   	host->pwrseq = NULL;
> @@ -63,17 +74,27 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
>   {
>   	struct mmc_pwrseq_simple *pwrseq;
>   	int ret = 0;
> +	int i;
>
>   	pwrseq = kzalloc(sizeof(struct mmc_pwrseq_simple), GFP_KERNEL);
>   	if (!pwrseq)
>   		return -ENOMEM;
>
> -	pwrseq->reset_gpio = gpiod_get_index(dev, "reset", 0, GPIOD_OUT_HIGH);
> -	if (IS_ERR(pwrseq->reset_gpio) &&
> -		PTR_ERR(pwrseq->reset_gpio) != -ENOENT &&
> -		PTR_ERR(pwrseq->reset_gpio) != -ENOSYS) {
> -		ret = PTR_ERR(pwrseq->reset_gpio);
> -		goto free;
> +	pwrseq->nr_gpios = of_gpio_named_count(dev->of_node, "reset-gpios");
> +	if (pwrseq->nr_gpios > 0) {

What happens if there are no gpios? This fuction should return -ENOENT 
and should not even try to allocate pwrseq?
Probably you should do of_gpio_named_count before allocating memory.

> +		pwrseq->reset_gpio = kzalloc(sizeof(struct gpio_desc *) *
> +					     pwrseq->nr_gpios, GFP_KERNEL);
> +
> +		for (i = 0; i < pwrseq->nr_gpios; i++) {
> +			pwrseq->reset_gpio[i] = gpiod_get_index(dev, "reset", i,
> +								GPIOD_OUT_HIGH);
> +			if (IS_ERR(pwrseq->reset_gpio[i]) &&
> +			    PTR_ERR(pwrseq->reset_gpio[i]) != -ENOENT &&
> +			    PTR_ERR(pwrseq->reset_gpio[i]) != -ENOSYS) {
> +				ret = PTR_ERR(pwrseq->reset_gpio[i]);

is simple to add:
	while(--i)
		gpiod_put(pwrseq->reset_gpio[i])


		
> +				goto free;
> +			}
> +		}


>   	}
>
>   	pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
> @@ -81,6 +102,13 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
>
>   	return 0;
>   free:
> +	if (pwrseq->nr_gpios > 0) {
> +		for (i = 0; i < pwrseq->nr_gpios; i++)
> +			if (!IS_ERR_OR_NULL(pwrseq->reset_gpio[i]))
> +				gpiod_put(pwrseq->reset_gpio[i]);
> +		kfree(pwrseq->reset_gpio);
> +	}
> +
>   	kfree(pwrseq);
>   	return ret;
>   }
>

I get a feeling that am just dumping my patch here.. If possible could 
you have look at it too.

Thanks,
srini
Javier Martinez Canillas Jan. 28, 2015, 4:13 p.m. UTC | #2
Hello Srinivas,

Thanks a lot for your feedback.

On 01/28/2015 03:01 PM, Srinivas Kandagatla wrote:
> Hi Javier,
> 
> You are in a lead of 3 hrs from me..
> Surprisingly I send very much same patch just few Mins ago :-)

:-)

I didn't find the posted patch you are referring too though, did you cc
linux-mmc?

> May be we can merge goods in both :-)
>

Sure, I want $subject to be generic enough to be useful for other platforms.

> On 28/01/15 10:10, Javier Martinez Canillas wrote:
>> Many WLAN attached to a SDIO/MMC interface, needs more than one pin for
>> their reset sequence. For example, is very common for chips to have two
>> pins: one for reset and one for power enable.
>>
>> This patch adds support for more reset pins to the pwrseq_simple driver
>> and instead hardcoding a fixed number, it uses the of_gpio_named_count()
>> since the MMC power sequence is only built when CONFIG_OF is enabled.
>>
>> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
>> ---
>>   drivers/mmc/core/pwrseq_simple.c | 54 ++++++++++++++++++++++++++++++----------
>>   1 file changed, 41 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
>> index 0958c696137f..9e51fe1051c5 100644
>> --- a/drivers/mmc/core/pwrseq_simple.c
>> +++ b/drivers/mmc/core/pwrseq_simple.c
>> @@ -11,6 +11,7 @@
>>   #include <linux/slab.h>
>>   #include <linux/device.h>
>>   #include <linux/err.h>
>> +#include <linux/of_gpio.h>
>>   #include <linux/gpio/consumer.h>
>>
>>   #include <linux/mmc/host.h>
>> @@ -19,34 +20,44 @@
>>
>>   struct mmc_pwrseq_simple {
>>   	struct mmc_pwrseq pwrseq;
>> -	struct gpio_desc *reset_gpio;
>> +	struct gpio_desc **reset_gpio;
> 
> May be renaming it to reset_gpios makes more sense..
>

Ok

> If you make this struct gpio_desc *reset_gpios[0]; You can aviod an 
> extra kmalloc and free ..
> 
>

That's a very good idea, thanks.

>> +	int nr_gpios;
>>   };
>>
>>   static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
>>   {
> 
> [...
>>   	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
>>   					struct mmc_pwrseq_simple, pwrseq);
>> +	int i;
>>
>> -	if (!IS_ERR(pwrseq->reset_gpio))
>> -		gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);
>> +	for (i = 0; i < pwrseq->nr_gpios; i++)
>> +		if (!IS_ERR(pwrseq->reset_gpio[i]))
>> +			gpiod_set_value_cansleep(pwrseq->reset_gpio[i], 1);
> 
> ...]
> 
>>   }
>>
>>   static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
>>   {
> 
> [...
> 
>>   	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
>>   					struct mmc_pwrseq_simple, pwrseq);
>> +	int i;
>>
>> -	if (!IS_ERR(pwrseq->reset_gpio))
>> -		gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);
>> +	for (i = 0; i < pwrseq->nr_gpios; i++)
>> +		if (!IS_ERR(pwrseq->reset_gpio[i]))
>> +			gpiod_set_value_cansleep(pwrseq->reset_gpio[i], 0);
> ...]
> 
> Now that we have more code in mmc_pwrseq_simple_post_power_on() and 
> mmc_pwrseq_simple_pre_power_on(), Just move most of them into a common 
> function like:
> 
> static void __mmc_pwrseq_simple_power_on_off(struct mmc_host *host,
> 						      bool on)
> {
> 	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
> 					struct mmc_pwrseq_simple, pwrseq);
> 	int i;
> 
> 	if (!IS_ERR(pwrseq->reset_gpios)) {
> 		for (i = 0; i < pwrseq->ngpios; i++)
> 			gpiod_set_value_cansleep(pwrseq->reset_gpios[i],
> 						 on ? : 0);
> 	}
> }
>
> static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
> {
> 	__mmc_pwrseq_simple_power_on_off(host, true);
> }
> 
> static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
> {
> 	__mmc_pwrseq_simple_power_on_off(host, false);
> }
> 
>

Sure, will do.

>>   }
>>
>>   static void mmc_pwrseq_simple_free(struct mmc_host *host)
>>   {
>>   	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
>>   					struct mmc_pwrseq_simple, pwrseq);
>> +	int i;
>>
>> -	if (!IS_ERR(pwrseq->reset_gpio))
>> -		gpiod_put(pwrseq->reset_gpio);
>> +	if (pwrseq->nr_gpios > 0) {
>> +		for (i = 0; i < pwrseq->nr_gpios; i++)
>> +			if (!IS_ERR(pwrseq->reset_gpio[i]))
>> +				gpiod_put(pwrseq->reset_gpio[i]);
>> +		kfree(pwrseq->reset_gpio);
>> +	}
>>
>>   	kfree(pwrseq);
>>   	host->pwrseq = NULL;
>> @@ -63,17 +74,27 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
>>   {
>>   	struct mmc_pwrseq_simple *pwrseq;
>>   	int ret = 0;
>> +	int i;
>>
>>   	pwrseq = kzalloc(sizeof(struct mmc_pwrseq_simple), GFP_KERNEL);
>>   	if (!pwrseq)
>>   		return -ENOMEM;
>>
>> -	pwrseq->reset_gpio = gpiod_get_index(dev, "reset", 0, GPIOD_OUT_HIGH);
>> -	if (IS_ERR(pwrseq->reset_gpio) &&
>> -		PTR_ERR(pwrseq->reset_gpio) != -ENOENT &&
>> -		PTR_ERR(pwrseq->reset_gpio) != -ENOSYS) {
>> -		ret = PTR_ERR(pwrseq->reset_gpio);
>> -		goto free;
>> +	pwrseq->nr_gpios = of_gpio_named_count(dev->of_node, "reset-gpios");
>> +	if (pwrseq->nr_gpios > 0) {
> 
> What happens if there are no gpios? This fuction should return -ENOENT 
> and should not even try to allocate pwrseq?

Not quite, the DT binding states that the GPIOs are optional so it should
not fail if no GPIOs are defined. 

> Probably you should do of_gpio_named_count before allocating memory.
>

I didn't do that because patch #4 "mmc: pwrseq_simple: Add optional reference
clock support" will need the struct mmc_pwrseq_simple even if no GPIOs are
defined.

A SDIO attached chip could require only an external clock or someone could
extend the pwrseq_simple driver to support an external regulator for example.

>> +		pwrseq->reset_gpio = kzalloc(sizeof(struct gpio_desc *) *
>> +					     pwrseq->nr_gpios, GFP_KERNEL);
>> +
>> +		for (i = 0; i < pwrseq->nr_gpios; i++) {
>> +			pwrseq->reset_gpio[i] = gpiod_get_index(dev, "reset", i,
>> +								GPIOD_OUT_HIGH);
>> +			if (IS_ERR(pwrseq->reset_gpio[i]) &&
>> +			    PTR_ERR(pwrseq->reset_gpio[i]) != -ENOENT &&
>> +			    PTR_ERR(pwrseq->reset_gpio[i]) != -ENOSYS) {
>> +				ret = PTR_ERR(pwrseq->reset_gpio[i]);
> 
> is simple to add:
> 	while(--i)
> 		gpiod_put(pwrseq->reset_gpio[i])
> 
> 
>

That's true, will change.

>> +				goto free;
>> +			}
>> +		}
> 
> 
>>   	}
>>
>>   	pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
>> @@ -81,6 +102,13 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
>>
>>   	return 0;
>>   free:
>> +	if (pwrseq->nr_gpios > 0) {
>> +		for (i = 0; i < pwrseq->nr_gpios; i++)
>> +			if (!IS_ERR_OR_NULL(pwrseq->reset_gpio[i]))
>> +				gpiod_put(pwrseq->reset_gpio[i]);
>> +		kfree(pwrseq->reset_gpio);
>> +	}
>> +
>>   	kfree(pwrseq);
>>   	return ret;
>>   }
>>
> 
> I get a feeling that am just dumping my patch here.. If possible could 
> you have look at it too.
>

Of course, do you have a link archive since I can't find it on my inbox.

> Thanks,
> srini
>

Again, thanks a lot and best regards,
Javier
Srinivas Kandagatla Jan. 28, 2015, 4:31 p.m. UTC | #3
On 28/01/15 16:13, Javier Martinez Canillas wrote:
> Hello Srinivas,
>
> Thanks a lot for your feedback.
>
> On 01/28/2015 03:01 PM, Srinivas Kandagatla wrote:
>> Hi Javier,
>>
>> You are in a lead of 3 hrs from me..
>> Surprisingly I send very much same patch just few Mins ago :-)
>
> :-)
>
> I didn't find the posted patch you are referring too though, did you cc
> linux-mmc?
>
>> May be we can merge goods in both :-)
>>
>
> Sure, I want $subject to be generic enough to be useful for other platforms.
>
>> On 28/01/15 10:10, Javier Martinez Canillas wrote:
>>> Many WLAN attached to a SDIO/MMC interface, needs more than one pin for
>>> their reset sequence. For example, is very common for chips to have two
>>> pins: one for reset and one for power enable.
>>>
>>> This patch adds support for more reset pins to the pwrseq_simple driver
>>> and instead hardcoding a fixed number, it uses the of_gpio_named_count()
>>> since the MMC power sequence is only built when CONFIG_OF is enabled.
>>>
>>> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
>>> ---
>>>    drivers/mmc/core/pwrseq_simple.c | 54 ++++++++++++++++++++++++++++++----------
>>>    1 file changed, 41 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
>>> index 0958c696137f..9e51fe1051c5 100644
>>> --- a/drivers/mmc/core/pwrseq_simple.c
>>> +++ b/drivers/mmc/core/pwrseq_simple.c
>>> @@ -11,6 +11,7 @@
>>>    #include <linux/slab.h>
>>>    #include <linux/device.h>
>>>    #include <linux/err.h>
>>> +#include <linux/of_gpio.h>
>>>    #include <linux/gpio/consumer.h>
>>>
>>>    #include <linux/mmc/host.h>
>>> @@ -19,34 +20,44 @@
>>>
>>>    struct mmc_pwrseq_simple {
>>>    	struct mmc_pwrseq pwrseq;
>>> -	struct gpio_desc *reset_gpio;
>>> +	struct gpio_desc **reset_gpio;
>>
>> May be renaming it to reset_gpios makes more sense..
>>
>
> Ok
>
>> If you make this struct gpio_desc *reset_gpios[0]; You can aviod an
>> extra kmalloc and free ..
>>
>>
>
> That's a very good idea, thanks.
>
>>> +	int nr_gpios;
>>>    };
>>>
>>>    static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
>>>    {
>>
>> [...
>>>    	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
>>>    					struct mmc_pwrseq_simple, pwrseq);
>>> +	int i;
>>>
>>> -	if (!IS_ERR(pwrseq->reset_gpio))
>>> -		gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);
>>> +	for (i = 0; i < pwrseq->nr_gpios; i++)
>>> +		if (!IS_ERR(pwrseq->reset_gpio[i]))
>>> +			gpiod_set_value_cansleep(pwrseq->reset_gpio[i], 1);
>>
>> ...]
>>
>>>    }
>>>
>>>    static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
>>>    {
>>
>> [...
>>
>>>    	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
>>>    					struct mmc_pwrseq_simple, pwrseq);
>>> +	int i;
>>>
>>> -	if (!IS_ERR(pwrseq->reset_gpio))
>>> -		gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);
>>> +	for (i = 0; i < pwrseq->nr_gpios; i++)
>>> +		if (!IS_ERR(pwrseq->reset_gpio[i]))
>>> +			gpiod_set_value_cansleep(pwrseq->reset_gpio[i], 0);
>> ...]
>>
>> Now that we have more code in mmc_pwrseq_simple_post_power_on() and
>> mmc_pwrseq_simple_pre_power_on(), Just move most of them into a common
>> function like:
>>
>> static void __mmc_pwrseq_simple_power_on_off(struct mmc_host *host,
>> 						      bool on)
>> {
>> 	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
>> 					struct mmc_pwrseq_simple, pwrseq);
>> 	int i;
>>
>> 	if (!IS_ERR(pwrseq->reset_gpios)) {
>> 		for (i = 0; i < pwrseq->ngpios; i++)
>> 			gpiod_set_value_cansleep(pwrseq->reset_gpios[i],
>> 						 on ? : 0);
>> 	}
>> }
>>
>> static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
>> {
>> 	__mmc_pwrseq_simple_power_on_off(host, true);
>> }
>>
>> static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
>> {
>> 	__mmc_pwrseq_simple_power_on_off(host, false);
>> }
>>
>>
>
> Sure, will do.
>
>>>    }
>>>
>>>    static void mmc_pwrseq_simple_free(struct mmc_host *host)
>>>    {
>>>    	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
>>>    					struct mmc_pwrseq_simple, pwrseq);
>>> +	int i;
>>>
>>> -	if (!IS_ERR(pwrseq->reset_gpio))
>>> -		gpiod_put(pwrseq->reset_gpio);
>>> +	if (pwrseq->nr_gpios > 0) {
>>> +		for (i = 0; i < pwrseq->nr_gpios; i++)
>>> +			if (!IS_ERR(pwrseq->reset_gpio[i]))
>>> +				gpiod_put(pwrseq->reset_gpio[i]);
>>> +		kfree(pwrseq->reset_gpio);
>>> +	}
>>>
>>>    	kfree(pwrseq);
>>>    	host->pwrseq = NULL;
>>> @@ -63,17 +74,27 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
>>>    {
>>>    	struct mmc_pwrseq_simple *pwrseq;
>>>    	int ret = 0;
>>> +	int i;
>>>
>>>    	pwrseq = kzalloc(sizeof(struct mmc_pwrseq_simple), GFP_KERNEL);
>>>    	if (!pwrseq)
>>>    		return -ENOMEM;
>>>
>>> -	pwrseq->reset_gpio = gpiod_get_index(dev, "reset", 0, GPIOD_OUT_HIGH);
>>> -	if (IS_ERR(pwrseq->reset_gpio) &&
>>> -		PTR_ERR(pwrseq->reset_gpio) != -ENOENT &&
>>> -		PTR_ERR(pwrseq->reset_gpio) != -ENOSYS) {
>>> -		ret = PTR_ERR(pwrseq->reset_gpio);
>>> -		goto free;
>>> +	pwrseq->nr_gpios = of_gpio_named_count(dev->of_node, "reset-gpios");
>>> +	if (pwrseq->nr_gpios > 0) {
>>
>> What happens if there are no gpios? This fuction should return -ENOENT
>> and should not even try to allocate pwrseq?
>
> Not quite, the DT binding states that the GPIOs are optional so it should
> not fail if no GPIOs are defined.
>
>> Probably you should do of_gpio_named_count before allocating memory.
>>
>
> I didn't do that because patch #4 "mmc: pwrseq_simple: Add optional reference
> clock support" will need the struct mmc_pwrseq_simple even if no GPIOs are
> defined.
>
> A SDIO attached chip could require only an external clock or someone could
> extend the pwrseq_simple driver to support an external regulator for example.

That makes sense.

>
>>> +		pwrseq->reset_gpio = kzalloc(sizeof(struct gpio_desc *) *
>>> +					     pwrseq->nr_gpios, GFP_KERNEL);
>>> +
>>> +		for (i = 0; i < pwrseq->nr_gpios; i++) {
>>> +			pwrseq->reset_gpio[i] = gpiod_get_index(dev, "reset", i,
>>> +								GPIOD_OUT_HIGH);
>>> +			if (IS_ERR(pwrseq->reset_gpio[i]) &&
>>> +			    PTR_ERR(pwrseq->reset_gpio[i]) != -ENOENT &&
>>> +			    PTR_ERR(pwrseq->reset_gpio[i]) != -ENOSYS) {
>>> +				ret = PTR_ERR(pwrseq->reset_gpio[i]);
>>
>> is simple to add:
>> 	while(--i)
>> 		gpiod_put(pwrseq->reset_gpio[i])
>>
>>
>>
>
> That's true, will change.
>
>>> +				goto free;
>>> +			}
>>> +		}
>>
>>
>>>    	}
>>>
>>>    	pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
>>> @@ -81,6 +102,13 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
>>>
>>>    	return 0;
>>>    free:
>>> +	if (pwrseq->nr_gpios > 0) {
>>> +		for (i = 0; i < pwrseq->nr_gpios; i++)
>>> +			if (!IS_ERR_OR_NULL(pwrseq->reset_gpio[i]))
>>> +				gpiod_put(pwrseq->reset_gpio[i]);
>>> +		kfree(pwrseq->reset_gpio);
>>> +	}
>>> +
>>>    	kfree(pwrseq);
>>>    	return ret;
>>>    }
>>>
>>
>> I get a feeling that am just dumping my patch here.. If possible could
>> you have look at it too.
>>
>
> Of course, do you have a link archive since I can't find it on my inbox.
I did send to linux-mmc@vger.kernel.org, Anyway i did forward you the patch.

thanks,
--srini
diff mbox

Patch

diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
index 0958c696137f..9e51fe1051c5 100644
--- a/drivers/mmc/core/pwrseq_simple.c
+++ b/drivers/mmc/core/pwrseq_simple.c
@@ -11,6 +11,7 @@ 
 #include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/err.h>
+#include <linux/of_gpio.h>
 #include <linux/gpio/consumer.h>
 
 #include <linux/mmc/host.h>
@@ -19,34 +20,44 @@ 
 
 struct mmc_pwrseq_simple {
 	struct mmc_pwrseq pwrseq;
-	struct gpio_desc *reset_gpio;
+	struct gpio_desc **reset_gpio;
+	int nr_gpios;
 };
 
 static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
 {
 	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
 					struct mmc_pwrseq_simple, pwrseq);
+	int i;
 
-	if (!IS_ERR(pwrseq->reset_gpio))
-		gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);
+	for (i = 0; i < pwrseq->nr_gpios; i++)
+		if (!IS_ERR(pwrseq->reset_gpio[i]))
+			gpiod_set_value_cansleep(pwrseq->reset_gpio[i], 1);
 }
 
 static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
 {
 	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
 					struct mmc_pwrseq_simple, pwrseq);
+	int i;
 
-	if (!IS_ERR(pwrseq->reset_gpio))
-		gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);
+	for (i = 0; i < pwrseq->nr_gpios; i++)
+		if (!IS_ERR(pwrseq->reset_gpio[i]))
+			gpiod_set_value_cansleep(pwrseq->reset_gpio[i], 0);
 }
 
 static void mmc_pwrseq_simple_free(struct mmc_host *host)
 {
 	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
 					struct mmc_pwrseq_simple, pwrseq);
+	int i;
 
-	if (!IS_ERR(pwrseq->reset_gpio))
-		gpiod_put(pwrseq->reset_gpio);
+	if (pwrseq->nr_gpios > 0) {
+		for (i = 0; i < pwrseq->nr_gpios; i++)
+			if (!IS_ERR(pwrseq->reset_gpio[i]))
+				gpiod_put(pwrseq->reset_gpio[i]);
+		kfree(pwrseq->reset_gpio);
+	}
 
 	kfree(pwrseq);
 	host->pwrseq = NULL;
@@ -63,17 +74,27 @@  int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
 {
 	struct mmc_pwrseq_simple *pwrseq;
 	int ret = 0;
+	int i;
 
 	pwrseq = kzalloc(sizeof(struct mmc_pwrseq_simple), GFP_KERNEL);
 	if (!pwrseq)
 		return -ENOMEM;
 
-	pwrseq->reset_gpio = gpiod_get_index(dev, "reset", 0, GPIOD_OUT_HIGH);
-	if (IS_ERR(pwrseq->reset_gpio) &&
-		PTR_ERR(pwrseq->reset_gpio) != -ENOENT &&
-		PTR_ERR(pwrseq->reset_gpio) != -ENOSYS) {
-		ret = PTR_ERR(pwrseq->reset_gpio);
-		goto free;
+	pwrseq->nr_gpios = of_gpio_named_count(dev->of_node, "reset-gpios");
+	if (pwrseq->nr_gpios > 0) {
+		pwrseq->reset_gpio = kzalloc(sizeof(struct gpio_desc *) *
+					     pwrseq->nr_gpios, GFP_KERNEL);
+
+		for (i = 0; i < pwrseq->nr_gpios; i++) {
+			pwrseq->reset_gpio[i] = gpiod_get_index(dev, "reset", i,
+								GPIOD_OUT_HIGH);
+			if (IS_ERR(pwrseq->reset_gpio[i]) &&
+			    PTR_ERR(pwrseq->reset_gpio[i]) != -ENOENT &&
+			    PTR_ERR(pwrseq->reset_gpio[i]) != -ENOSYS) {
+				ret = PTR_ERR(pwrseq->reset_gpio[i]);
+				goto free;
+			}
+		}
 	}
 
 	pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
@@ -81,6 +102,13 @@  int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
 
 	return 0;
 free:
+	if (pwrseq->nr_gpios > 0) {
+		for (i = 0; i < pwrseq->nr_gpios; i++)
+			if (!IS_ERR_OR_NULL(pwrseq->reset_gpio[i]))
+				gpiod_put(pwrseq->reset_gpio[i]);
+		kfree(pwrseq->reset_gpio);
+	}
+
 	kfree(pwrseq);
 	return ret;
 }