diff options
| author | Kever Yang <kever.yang@rock-chips.com> | 2017-04-24 10:27:49 +0800 |
|---|---|---|
| committer | Simon Glass <sjg@chromium.org> | 2017-05-10 13:37:21 -0600 |
| commit | 0b60111aa66f51d05473a375070ca72d073a6fd3 (patch) | |
| tree | 48068d473dd00ed00a70b4a68cc956a04f049a62 /drivers/power/regulator | |
| parent | a66726838e9227ea8b9c6a1402d6ca89384c1b56 (diff) | |
| download | u-boot-0b60111aa66f51d05473a375070ca72d073a6fd3.tar.gz u-boot-0b60111aa66f51d05473a375070ca72d073a6fd3.tar.xz u-boot-0b60111aa66f51d05473a375070ca72d073a6fd3.zip | |
power: regulator: pwm: support pwm polarity setting
The latest kernel PWM drivers enable the polarity settings. When system
run from U-Boot to kerenl, if there are differences in polarity set or
duty cycle, the PMW will re-init:
close -> set polarity and duty cycle -> enable the PWM.
The power supply controled by pwm regulator may have voltage shaking,
which lead to the system not stable.
Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'drivers/power/regulator')
| -rw-r--r-- | drivers/power/regulator/pwm_regulator.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/power/regulator/pwm_regulator.c b/drivers/power/regulator/pwm_regulator.c index 4875238e43..a6c9fccd68 100644 --- a/drivers/power/regulator/pwm_regulator.c +++ b/drivers/power/regulator/pwm_regulator.c @@ -24,6 +24,12 @@ struct pwm_regulator_info { int pwm_id; /* the period of one PWM cycle */ int period_ns; + /* + * the polarity of one PWM + * 0: normal polarity + * 1: inverted polarity + */ + bool polarity; struct udevice *pwm; /* initialize voltage of regulator */ unsigned int init_voltage; @@ -49,7 +55,7 @@ static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV) int max_uV = priv->max_voltage; int diff = max_uV - min_uV; - return 100 - (((req_uV * 100) - (min_uV * 100)) / diff); + return ((req_uV * 100) - (min_uV * 100)) / diff; } static int pwm_regulator_get_voltage(struct udevice *dev) @@ -67,6 +73,12 @@ static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt) duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt); + ret = pwm_set_invert(priv->pwm, priv->pwm_id, priv->polarity); + if (ret) { + dev_err(dev, "Failed to init PWM\n"); + return ret; + } + ret = pwm_set_config(priv->pwm, priv->pwm_id, (priv->period_ns / 100) * duty_cycle, priv->period_ns); if (ret) { @@ -97,9 +109,9 @@ static int pwm_regulator_ofdata_to_platdata(struct udevice *dev) debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret); return ret; } - /* TODO: pwm_id here from device tree if needed */ priv->period_ns = args.args[1]; + priv->polarity = args.args[2]; priv->init_voltage = fdtdec_get_int(blob, node, "regulator-init-microvolt", -1); |