Commit 934f1f48 authored by Javier Martinez Canillas's avatar Javier Martinez Canillas Committed by Ulf Hansson
Browse files

mmc: pwrseq_simple: Extend to support more pins 



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: default avatarJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent a1d7579b

drivers/mmc/core/pwrseq_simple.c

+40 −15
Original line number Diff line number Diff line
@@ -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>
@@ -19,16 +20,26 @@ 


struct mmc_pwrseq_simple {

	struct mmc_pwrseq pwrseq;

	struct gpio_desc *reset_gpio;

	int nr_gpios;

	struct gpio_desc *reset_gpios[0];

};



static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,

					      int value)

{

	int i;



	for (i = 0; i < pwrseq->nr_gpios; i++)

		if (!IS_ERR(pwrseq->reset_gpios[i]))

			gpiod_set_value_cansleep(pwrseq->reset_gpios[i], value);

}



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);



	if (!IS_ERR(pwrseq->reset_gpio))

		gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);

	mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);

}



static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
@@ -36,17 +47,18 @@ 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);



	if (!IS_ERR(pwrseq->reset_gpio))

		gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);

	mmc_pwrseq_simple_set_gpios_value(pwrseq, 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);

	for (i = 0; i < pwrseq->nr_gpios; i++)

		if (!IS_ERR(pwrseq->reset_gpios[i]))

			gpiod_put(pwrseq->reset_gpios[i]);



	kfree(pwrseq);

	host->pwrseq = NULL;
@@ -62,20 +74,33 @@ static struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = { 
int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)

{

	struct mmc_pwrseq_simple *pwrseq;

	int ret = 0;

	int i, nr_gpios, ret = 0;



	pwrseq = kzalloc(sizeof(struct mmc_pwrseq_simple), GFP_KERNEL);

	nr_gpios = of_gpio_named_count(dev->of_node, "reset-gpios");

	if (nr_gpios < 0)

		nr_gpios = 0;



	pwrseq = kzalloc(sizeof(struct mmc_pwrseq_simple) + nr_gpios *

			 sizeof(struct gpio_desc *), 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);

	for (i = 0; i < nr_gpios; i++) {

		pwrseq->reset_gpios[i] = gpiod_get_index(dev, "reset", i,

							 GPIOD_OUT_HIGH);

		if (IS_ERR(pwrseq->reset_gpios[i]) &&

		    PTR_ERR(pwrseq->reset_gpios[i]) != -ENOENT &&

		    PTR_ERR(pwrseq->reset_gpios[i]) != -ENOSYS) {

			ret = PTR_ERR(pwrseq->reset_gpios[i]);



			while (--i)

				gpiod_put(pwrseq->reset_gpios[i]);



			goto free;

		}

	}



	pwrseq->nr_gpios = nr_gpios;

	pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;

	host->pwrseq = &pwrseq->pwrseq;

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