Some WLAN chips attached to a SDIO interface, need a reference clock. Since this is very common, extend the prseq_simple driver to support an optional clock that is enabled prior the card power up procedure. Note: the external clock is optional. Thus an error is not returned if the clock is not found. Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx> --- Changes since v1: - Rebase on top of latest changes. - Use IS_ERR() instead of checking for NULL to see if the clock exists. --- drivers/mmc/core/pwrseq_simple.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c index e53d3c7e059c..5e34c77efa5e 100644 --- a/drivers/mmc/core/pwrseq_simple.c +++ b/drivers/mmc/core/pwrseq_simple.c @@ -7,6 +7,7 @@ * * Simple MMC power sequence management */ +#include <linux/clk.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/device.h> @@ -20,6 +21,7 @@ struct mmc_pwrseq_simple { struct mmc_pwrseq pwrseq; + struct clk *ext_clk; int nr_gpios; struct gpio_desc *reset_gpios[0]; }; @@ -39,6 +41,9 @@ 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->ext_clk)) + clk_prepare_enable(pwrseq->ext_clk); + mmc_pwrseq_simple_set_gpios_value(pwrseq, 1); } @@ -50,6 +55,17 @@ static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host) mmc_pwrseq_simple_set_gpios_value(pwrseq, 0); } +static void mmc_pwrseq_simple_power_off(struct mmc_host *host) +{ + struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq, + struct mmc_pwrseq_simple, pwrseq); + + mmc_pwrseq_simple_set_gpios_value(pwrseq, 1); + + if (!IS_ERR(pwrseq->ext_clk)) + clk_disable_unprepare(pwrseq->ext_clk); +} + static void mmc_pwrseq_simple_free(struct mmc_host *host) { struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq, @@ -60,6 +76,9 @@ static void mmc_pwrseq_simple_free(struct mmc_host *host) if (!IS_ERR(pwrseq->reset_gpios[i])) gpiod_put(pwrseq->reset_gpios[i]); + if (!IS_ERR(pwrseq->ext_clk)) + clk_put(pwrseq->ext_clk); + kfree(pwrseq); host->pwrseq = NULL; } @@ -67,7 +86,7 @@ static void mmc_pwrseq_simple_free(struct mmc_host *host) 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, + .power_off = mmc_pwrseq_simple_power_off, .free = mmc_pwrseq_simple_free, }; @@ -85,6 +104,14 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev) if (!pwrseq) return -ENOMEM; + pwrseq->ext_clk = clk_get(dev, "ext_clock"); + if (IS_ERR(pwrseq->ext_clk) && + PTR_ERR(pwrseq->ext_clk) != -ENOENT && + PTR_ERR(pwrseq->ext_clk) != -ENOSYS) { + ret = PTR_ERR(pwrseq->ext_clk); + goto free; + } + for (i = 0; i < nr_gpios; i++) { pwrseq->reset_gpios[i] = gpiod_get_index(dev, "reset", i, GPIOD_OUT_HIGH); @@ -96,7 +123,7 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev) while (--i) gpiod_put(pwrseq->reset_gpios[i]); - goto free; + goto clk_put; } } @@ -105,6 +132,9 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev) host->pwrseq = &pwrseq->pwrseq; return 0; +clk_put: + if (!IS_ERR(pwrseq->ext_clk)) + clk_put(pwrseq->ext_clk); free: kfree(pwrseq); return ret; -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html