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authorUlf Hansson2017-05-06 11:43:05 +0200
committerUlf Hansson2017-05-23 14:17:36 +0200
commite9256e142f597edf90c68cec22db4c4aebaa27de (patch)
treed46304bb84308db1b084819e36db02aaeadeb228
parentc477ebe21fabe0010a2ed324ce3a1762c757d867 (diff)
mmc: pwrseq_simple: Parse DTS for the power-off-delay-us property
If the optional power-off-delay-us property is found, insert the corresponding delay after asserting the GPIO during power off. This enables a graceful shutdown sequence for some devices. Cc: linux-mmc@vger.kernel.org Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
-rw-r--r--drivers/mmc/core/pwrseq_simple.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
index 1304160de168..13ef162cf066 100644
--- a/drivers/mmc/core/pwrseq_simple.c
+++ b/drivers/mmc/core/pwrseq_simple.c
@@ -27,6 +27,7 @@ struct mmc_pwrseq_simple {
struct mmc_pwrseq pwrseq;
bool clk_enabled;
u32 post_power_on_delay_ms;
+ u32 power_off_delay_us;
struct clk *ext_clk;
struct gpio_descs *reset_gpios;
};
@@ -78,6 +79,10 @@ static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
+ if (pwrseq->power_off_delay_us)
+ usleep_range(pwrseq->power_off_delay_us,
+ 2 * pwrseq->power_off_delay_us);
+
if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {
clk_disable_unprepare(pwrseq->ext_clk);
pwrseq->clk_enabled = false;
@@ -119,6 +124,8 @@ static int mmc_pwrseq_simple_probe(struct platform_device *pdev)
device_property_read_u32(dev, "post-power-on-delay-ms",
&pwrseq->post_power_on_delay_ms);
+ device_property_read_u32(dev, "power-off-delay-us",
+ &pwrseq->power_off_delay_us);
pwrseq->pwrseq.dev = dev;
pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;