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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: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Javier Martinez Canillas 2015-01-29 16:00:04 +01:00 committed by Ulf Hansson
parent a1d7579b25
commit 934f1f4833
1 changed files with 40 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
drivers/mmc/core/pwrseq_simple.c
View File

@ -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);
goto free;
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;