[PATCH v2 2/6] mmc: pwrseq_simple: Extend to support more pins
From: Javier Martinez Canillas <hidden>
Date: 2015-01-28 21:37:58
Also in:
linux-devicetree, linux-mmc, linux-samsung-soc, lkml
Subsystem:
multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Ulf Hansson, Linus Torvalds
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 <redacted>
Signed-off-by: Srinivas Kandagatla <redacted>
---
Changes since v1:
- Many code cleanups suggested by Srinivas Kandagatla
* Rename reset_gpio array to reset_gpios.
* Use a zero length array for reset_gpios to avoid a kmalloc.
* Refactor GPIO assert and de-ssert logic into a common function.
* Simplify gpiod_put logic in case of gpiod_get error.
---
drivers/mmc/core/pwrseq_simple.c | 55 +++++++++++++++++++++++++++++-----------
1 file changed, 40 insertions(+), 15 deletions(-)
diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
index 0958c696137f..e53d3c7e059c 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>
@@ -19,16 +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;
--
2.1.3