From 39dd00fc5dbae60c4165a06b50420a36270c68ab Mon Sep 17 00:00:00 2001 From: Peng Fan Date: Thu, 26 Jul 2018 19:47:24 +0800 Subject: [PATCH] drivers: regulator: fixed: add u-boot, off-on-delay-us Add u-boot,off-on-delay-us for fixed regulator. Depends on board design, the gpio regulator sometimes connects with a big capacitance. When need to off, then on the regulator, if there is no enough delay, the voltage does not drop to 0, so introduce this property to handle such case. Signed-off-by: Peng Fan Reviewed-by: Simon Glass Cc: Masahiro Yamada --- doc/device-tree-bindings/regulator/fixed.txt | 1 + drivers/power/regulator/fixed.c | 6 ++++++ 2 files changed, 7 insertions(+) diff --git a/doc/device-tree-bindings/regulator/fixed.txt b/doc/device-tree-bindings/regulator/fixed.txt index 5fd9033fea..453d2bef44 100644 --- a/doc/device-tree-bindings/regulator/fixed.txt +++ b/doc/device-tree-bindings/regulator/fixed.txt @@ -11,6 +11,7 @@ Required properties: Optional properties: - gpio: GPIO to use for enable control - startup-delay-us: startup time in microseconds +- u-boot,off-on-delay-us: off delay time in microseconds - regulator constraints (binding info: regulator.txt) - enable-active-high: Polarity of GPIO is Active high. If this property is missing, the default assumed is Active low. diff --git a/drivers/power/regulator/fixed.c b/drivers/power/regulator/fixed.c index 0be5b7bd51..a99aa78310 100644 --- a/drivers/power/regulator/fixed.c +++ b/drivers/power/regulator/fixed.c @@ -16,6 +16,7 @@ struct fixed_regulator_platdata { struct gpio_desc gpio; /* GPIO for regulator enable control */ unsigned int startup_delay_us; + unsigned int off_on_delay_us; }; static int fixed_regulator_ofdata_to_platdata(struct udevice *dev) @@ -50,6 +51,8 @@ static int fixed_regulator_ofdata_to_platdata(struct udevice *dev) /* Get optional ramp up delay */ dev_pdata->startup_delay_us = dev_read_u32_default(dev, "startup-delay-us", 0); + dev_pdata->off_on_delay_us = + dev_read_u32_default(dev, "u-boot,off-on-delay-us", 0); return 0; } @@ -123,6 +126,9 @@ static int fixed_regulator_set_enable(struct udevice *dev, bool enable) udelay(dev_pdata->startup_delay_us); debug("%s: done\n", __func__); + if (!enable && dev_pdata->off_on_delay_us) + udelay(dev_pdata->off_on_delay_us); + return 0; } -- 2.39.5