diff options
| author | Krzysztof Kozlowski <krzk@kernel.org> | 2019-03-06 19:37:54 +0100 |
|---|---|---|
| committer | Minkyu Kang <mk7.kang@samsung.com> | 2019-03-11 15:53:19 +0900 |
| commit | e66d1cb3c2344ee5bbf2059e75fa94350aea9f5f (patch) | |
| tree | 4a66659f0998cacf6dacd77605773ab66d78c22d /drivers/power/regulator | |
| parent | fce86100606d14e53517a3601849646e69715465 (diff) | |
| download | u-boot-e66d1cb3c2344ee5bbf2059e75fa94350aea9f5f.tar.gz | |
regulator: Add support for ramp delay
Changing voltage and enabling regulator might require delays so the
regulator stabilizes at expected level.
Add support for "regulator-ramp-delay" binding which can introduce
required time to both enabling the regulator and to changing the
voltage.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
Diffstat (limited to 'drivers/power/regulator')
| -rw-r--r-- | drivers/power/regulator/regulator-uclass.c | 47 |
1 files changed, 45 insertions, 2 deletions
diff --git a/drivers/power/regulator/regulator-uclass.c b/drivers/power/regulator/regulator-uclass.c index 6f355b969a..9118b8eb39 100644 --- a/drivers/power/regulator/regulator-uclass.c +++ b/drivers/power/regulator/regulator-uclass.c @@ -35,10 +35,22 @@ int regulator_get_value(struct udevice *dev) return ops->get_value(dev); } +static void regulator_set_value_ramp_delay(struct udevice *dev, int old_uV, + int new_uV, unsigned int ramp_delay) +{ + int delay = DIV_ROUND_UP(abs(new_uV - old_uV), ramp_delay); + + debug("regulator %s: delay %u us (%d uV -> %d uV)\n", dev->name, delay, + old_uV, new_uV); + + udelay(delay); +} + int regulator_set_value(struct udevice *dev, int uV) { const struct dm_regulator_ops *ops = dev_get_driver_ops(dev); struct dm_regulator_uclass_platdata *uc_pdata; + int ret, old_uV = uV, is_enabled = 0; uc_pdata = dev_get_uclass_platdata(dev); if (uc_pdata->min_uV != -ENODATA && uV < uc_pdata->min_uV) @@ -49,7 +61,20 @@ int regulator_set_value(struct udevice *dev, int uV) if (!ops || !ops->set_value) return -ENOSYS; - return ops->set_value(dev, uV); + if (uc_pdata->ramp_delay) { + is_enabled = regulator_get_enable(dev); + old_uV = regulator_get_value(dev); + } + + ret = ops->set_value(dev, uV); + + if (!ret) { + if (uc_pdata->ramp_delay && old_uV > 0 && is_enabled) + regulator_set_value_ramp_delay(dev, old_uV, uV, + uc_pdata->ramp_delay); + } + + return ret; } /* @@ -107,6 +132,7 @@ int regulator_set_enable(struct udevice *dev, bool enable) { const struct dm_regulator_ops *ops = dev_get_driver_ops(dev); struct dm_regulator_uclass_platdata *uc_pdata; + int ret, old_enable = 0; if (!ops || !ops->set_enable) return -ENOSYS; @@ -115,7 +141,22 @@ int regulator_set_enable(struct udevice *dev, bool enable) if (!enable && uc_pdata->always_on) return -EACCES; - return ops->set_enable(dev, enable); + if (uc_pdata->ramp_delay) + old_enable = regulator_get_enable(dev); + + ret = ops->set_enable(dev, enable); + if (!ret) { + if (uc_pdata->ramp_delay && !old_enable && enable) { + int uV = regulator_get_value(dev); + + if (uV > 0) { + regulator_set_value_ramp_delay(dev, 0, uV, + uc_pdata->ramp_delay); + } + } + } + + return ret; } int regulator_set_enable_if_allowed(struct udevice *dev, bool enable) @@ -335,6 +376,8 @@ static int regulator_pre_probe(struct udevice *dev) -ENODATA); uc_pdata->always_on = dev_read_bool(dev, "regulator-always-on"); uc_pdata->boot_on = dev_read_bool(dev, "regulator-boot-on"); + uc_pdata->ramp_delay = dev_read_u32_default(dev, "regulator-ramp-delay", + 0); /* Those values are optional (-ENODATA if unset) */ if ((uc_pdata->min_uV != -ENODATA) && |