From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulf Hansson Subject: [PATCH V4 4/4] mmc: pwrseq_simple: Add support for a reset GPIO pin Date: Mon, 19 Jan 2015 10:13:04 +0100 Message-ID: <1421658784-11980-5-git-send-email-ulf.hansson@linaro.org> References: <1421658784-11980-1-git-send-email-ulf.hansson@linaro.org> Return-path: In-Reply-To: <1421658784-11980-1-git-send-email-ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-mmc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Chris Ball Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Linus Walleij , Mark Brown , Arnd Bergmann , Alexandre Courbot , Arend van Spriel , Sascha Hauer , Olof Johansson , Russell King , Hans de Goede , Doug Anderson , NeilBrown , Tomeu Vizoso , Mark Rutland , Ulf Hansson List-Id: devicetree@vger.kernel.org The need for reset GPIOs has several times been pointed out from erlier posted patchsets. Especially some WLAN chips which are attached to an SDIO interface may use a GPIO reset. The reset GPIO is asserted at initialization and prior we start the power up procedure. The GPIO will be de-asserted right after the power has been provided to the card, from the ->post_power_on() callback. Note, the reset GPIO is optional. Thus we don't return an error even if we can't find a GPIO for the consumer. Signed-off-by: Ulf Hansson --- Changes in v4: - Fixed call to kfree(). --- drivers/mmc/core/pwrseq_simple.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c index 61c991e..0958c69 100644 --- a/drivers/mmc/core/pwrseq_simple.c +++ b/drivers/mmc/core/pwrseq_simple.c @@ -11,6 +11,7 @@ #include #include #include +#include #include @@ -18,31 +19,68 @@ struct mmc_pwrseq_simple { struct mmc_pwrseq pwrseq; + struct gpio_desc *reset_gpio; }; +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); +} + +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); +} + static void mmc_pwrseq_simple_free(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_put(pwrseq->reset_gpio); + kfree(pwrseq); host->pwrseq = NULL; } static struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = { + .pre_power_on = mmc_pwrseq_simple_pre_power_on, + .post_power_on = mmc_pwrseq_simple_post_power_on, + .power_off = mmc_pwrseq_simple_pre_power_on, .free = mmc_pwrseq_simple_free, }; int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev) { struct mmc_pwrseq_simple *pwrseq; + int ret = 0; 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->pwrseq.ops = &mmc_pwrseq_simple_ops; host->pwrseq = &pwrseq->pwrseq; return 0; +free: + kfree(pwrseq); + return ret; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html