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author | Javier Martinez Canillas <javier.martinez@collabora.co.uk> | 2015-01-29 16:00:06 +0100 |
---|---|---|
committer | Ulf Hansson <ulf.hansson@linaro.org> | 2015-01-30 12:10:23 +0100 |
commit | c13045b1e939a9ecffab4a8f8d514e8a2a0bd2c9 (patch) | |
tree | 8485f823dafec20c596457251ad36826d30cc293 /drivers/mmc/core | |
parent | 3f656a168c70a583a5d87614eb4a707abd7f80b9 (diff) | |
download | linux-c13045b1e939a9ecffab4a8f8d514e8a2a0bd2c9.tar.gz linux-c13045b1e939a9ecffab4a8f8d514e8a2a0bd2c9.tar.bz2 linux-c13045b1e939a9ecffab4a8f8d514e8a2a0bd2c9.zip |
mmc: pwrseq_simple: Add optional reference clock support
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@collabora.co.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc/core')
-rw-r--r-- | drivers/mmc/core/pwrseq_simple.c | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c index e53d3c7e059c..e9f1d8d84613 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 +21,8 @@ struct mmc_pwrseq_simple { struct mmc_pwrseq pwrseq; + bool clk_enabled; + struct clk *ext_clk; int nr_gpios; struct gpio_desc *reset_gpios[0]; }; @@ -39,6 +42,11 @@ 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) && !pwrseq->clk_enabled) { + clk_prepare_enable(pwrseq->ext_clk); + pwrseq->clk_enabled = true; + } + mmc_pwrseq_simple_set_gpios_value(pwrseq, 1); } @@ -50,6 +58,19 @@ 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) && pwrseq->clk_enabled) { + clk_disable_unprepare(pwrseq->ext_clk); + pwrseq->clk_enabled = false; + } +} + static void mmc_pwrseq_simple_free(struct mmc_host *host) { struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq, @@ -60,6 +81,9 @@ 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 +91,7 @@ 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 +109,13 @@ 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) { + 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 +127,7 @@ 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 +136,9 @@ 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; |