Hi Kever,
On 19 April 2017 at 03:37, Kever Yang kever.yang@rock-chips.com wrote:
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
Changes in v3:
- use bool type for polarity
- add sambox test
sandbox
Also this is actually in another patch
Please split this inot the uclass/header change and the rockchip change. The latter should have a rockchip: tag.
For both when you resend you can add:
Acked-by: Simon Glass sjg@chromium.org
Changes in v2:
- use pwm_set_invert() instead of pwm_set_init()
- add comment for polarity
drivers/power/regulator/pwm_regulator.c | 16 ++++++++++++++-- drivers/pwm/pwm-uclass.c | 10 ++++++++++ drivers/pwm/rk_pwm.c | 17 ++++++++++++++++- include/pwm.h | 19 +++++++++++++++++++ 4 files changed, 59 insertions(+), 3 deletions(-)
diff --git a/drivers/power/regulator/pwm_regulator.c b/drivers/power/regulator/pwm_regulator.c index 4875238..a6c9fcc 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
use false, true
*/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);diff --git a/drivers/pwm/pwm-uclass.c b/drivers/pwm/pwm-uclass.c index c2200af..69051fe 100644 --- a/drivers/pwm/pwm-uclass.c +++ b/drivers/pwm/pwm-uclass.c @@ -9,6 +9,16 @@ #include <dm.h> #include <pwm.h>
+int pwm_set_invert(struct udevice *dev, uint channel, bool polarity) +{
struct pwm_ops *ops = pwm_get_ops(dev);if (!ops->set_invert)return -ENOSYS;return ops->set_invert(dev, channel, polarity);+}
int pwm_set_config(struct udevice *dev, uint channel, uint period_ns, uint duty_ns) { diff --git a/drivers/pwm/rk_pwm.c b/drivers/pwm/rk_pwm.c index 9254f5b..f3b2f76 100644 --- a/drivers/pwm/rk_pwm.c +++ b/drivers/pwm/rk_pwm.c @@ -21,8 +21,22 @@ DECLARE_GLOBAL_DATA_PTR; struct rk_pwm_priv { struct rk3288_pwm *regs; ulong freq;
uint enable_conf;};
+static int rk_pwm_set_invert(struct udevice *dev, uint channel, bool polarity) +{
struct rk_pwm_priv *priv = dev_get_priv(dev);debug("%s: polarity=%u\n", __func__, polarity);if (polarity)priv->enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSTIVE;elsepriv->enable_conf |= PWM_DUTY_POSTIVE | PWM_INACTIVE_NEGATIVE;return 0;+}
static int rk_pwm_set_config(struct udevice *dev, uint channel, uint period_ns, uint duty_ns) { @@ -32,7 +46,7 @@ static int rk_pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
debug("%s: period_ns=%u, duty_ns=%u\n", __func__, period_ns, duty_ns); writel(PWM_SEL_SRC_CLK | PWM_OUTPUT_LEFT | PWM_LP_DISABLE |
PWM_CONTINUOUS | PWM_DUTY_POSTIVE | PWM_INACTIVE_POSTIVE |
PWM_CONTINUOUS | priv->enable_conf | RK_PWM_DISABLE, ®s->ctrl);@@ -83,6 +97,7 @@ static int rk_pwm_probe(struct udevice *dev) }
static const struct pwm_ops rk_pwm_ops = {
.set_invert = rk_pwm_set_invert, .set_config = rk_pwm_set_config, .set_enable = rk_pwm_set_enable,}; diff --git a/include/pwm.h b/include/pwm.h index 851915e..ebee227 100644 --- a/include/pwm.h +++ b/include/pwm.h @@ -34,6 +34,15 @@ struct pwm_ops { * @return 0 if OK, -ve on error */ int (*set_enable)(struct udevice *dev, uint channel, bool enable);
/*** set_invert() - Set the PWM invert** @dev: PWM device to update* @channel: PWM channel to update* @polarity: true to invert, false to keep normal polarity* @return 0 if OK, -ve on error*/int (*set_invert)(struct udevice *dev, uint channel, bool polarity);};
#define pwm_get_ops(dev) ((struct pwm_ops *)(dev)->driver->ops) @@ -60,6 +69,16 @@ int pwm_set_config(struct udevice *dev, uint channel, uint period_ns, */ int pwm_set_enable(struct udevice *dev, uint channel, bool enable);
+/**
- pwm_set_invert() - Set pwm default polarity
- @dev: PWM device to update
- @channel: PWM channel to update
- @polarity: true to invert, false to keep normal polarity
- @return 0 if OK, -ve on error
- */
+int pwm_set_invert(struct udevice *dev, uint channel, bool polarity);
/* Legacy interface */ #ifndef CONFIG_DM_PWM int pwm_init (int pwm_id, int div, int invert); -- 1.9.1
Regards, Simon