On 04/10/2017 03:28 AM, Simon Glass wrote:
Hi,
On 7 April 2017 at 05:02, Kever Yang <kever.y...@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: Kever Yang <kever.y...@rock-chips.com>
---
drivers/power/regulator/pwm_regulator.c | 12 ++++++++++--
drivers/pwm/pwm-uclass.c | 10 ++++++++++
drivers/pwm/rk_pwm.c | 17 ++++++++++++++++-
include/pwm.h | 9 +++++++++
4 files changed, 45 insertions(+), 3 deletions(-)
If the generic uclass change and the rk change can be separated, it is
good to do it.
Also we should have a test for pwm (test/dm/pwm.c). Are you able to do
that? If not I could give it a try.
we have no plan to do it.
diff --git a/drivers/power/regulator/pwm_regulator.c
b/drivers/power/regulator/pwm_regulator.c
index 4875238..f8a6712 100644
--- a/drivers/power/regulator/pwm_regulator.c
+++ b/drivers/power/regulator/pwm_regulator.c
@@ -24,6 +24,8 @@ struct pwm_regulator_info {
int pwm_id;
/* the period of one PWM cycle */
int period_ns;
+ /* the polarity of one PWM */
+ int polarity;
Can you update the comment to indicate what the values mean? E.g. is 0
the normal polarity and 1 inverted?
0 : normal polarity
1 : inverted polarity
I will update the comment next version.
struct udevice *pwm;
/* initialize voltage of regulator */
unsigned int init_voltage;
@@ -49,7 +51,7 @@ 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 +69,12 @@ static int pwm_regulator_set_voltage(struct udevice *dev,
int uvolt)
duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt);
+ ret = pwm_set_init(priv->pwm, priv->pwm_id, priv->polarity);
I wonder if it would be better to combine the polarity into the
pwm_set_config() call? Then we can do everything in one call. If not
then I think pwm_set_invert() would be a better name.
The polarity set only once, so we set it in pwm_set_init() call.
Using pwm_set_invert, of course, is also possible.
+ 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 +105,9 @@ 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];
Does this mean that the binding has this argument and we have been ignoring it?
Can you bring in the DT binding file from Linux to U-Boot also?
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..287a7f3 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_init(struct udevice *dev, uint channel, uint polarity)
+{
+ struct pwm_ops *ops = pwm_get_ops(dev);
+
+ if (!ops->set_init)
+ return -ENOSYS;
+
+ return ops->set_init(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..5ff1e00 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_init(struct udevice *dev, uint channel, uint 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;
+ else
+ priv->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_init = rk_pwm_set_init,
.set_config = rk_pwm_set_config,
.set_enable = rk_pwm_set_enable,
};
diff --git a/include/pwm.h b/include/pwm.h
index 851915e..a66ee1f 100644
--- a/include/pwm.h
+++ b/include/pwm.h
@@ -14,6 +14,15 @@
/* struct pwm_ops: Operations for the PWM uclass */
struct pwm_ops {
/**
+ * set_init() - Set the PWM invert
+ *
+ * @dev: PWM device to update
+ * @channel: PWM channel to update
+ * @polarity: PWM invert polarity
+ * @return 0 if OK, -ve on error
+ */
+ int (*set_init)(struct udevice *dev, uint channel, uint polarity);
+ /**
* set_config() - Set the PWM configuration
*
* @dev: PWM device to update
--
1.9.1
Regards,
Simon
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