From: "david.wu" <[email protected]>
If the pwm was not enabled at uboot loader, pwm could not work for clock
always disabled at pwm driver. The pwm clock is enabled at beginning of
pwm_apply(), but disabled at end of pwm_apply().
If the pwm was enabled at uboot loader, pwm clock is always enabled unless
closed by ATF. The pwm-backlight might turn off the power at early suspend,
should disable pwm clock for saving power consume.
It is important to provide opportunity to enable/disable clock at pwm driver,
the pwm consumer should ensure correct order to call pwm enable/disable, and
pwm driver ensure state of pwm clock synchronized with pwm enabled state.
Fixes: 2bf1c98aa5a4 ("pwm: rockchip: Add support for atomic update")
Cc: [email protected]
Signed-off-by: David Wu <[email protected]>
Reviewed-by: Boris Brezillon <[email protected]>
---
change in v2:
- change the function name from rk_pwm_enable to rockchip_pwm_enable
drivers/pwm/pwm-rockchip.c | 40 +++++++++++++++++++++++++++++++++-------
1 file changed, 33 insertions(+), 7 deletions(-)
diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index ef89df1..744d561 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -191,6 +191,28 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
return 0;
}
+static int rockchip_pwm_enable(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ bool enable,
+ enum pwm_polarity polarity)
+{
+ struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+ int ret;
+
+ if (enable) {
+ ret = clk_enable(pc->clk);
+ if (ret)
+ return ret;
+ }
+
+ pc->data->set_enable(chip, pwm, enable, polarity);
+
+ if (!enable)
+ clk_disable(pc->clk);
+
+ return 0;
+}
+
static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
struct pwm_state *state)
{
@@ -207,22 +229,26 @@ static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
return ret;
if (state->polarity != curstate.polarity && enabled) {
- pc->data->set_enable(chip, pwm, false, state->polarity);
+ ret = rockchip_pwm_enable(chip, pwm, false, state->polarity);
+ if (ret)
+ goto out;
enabled = false;
}
ret = rockchip_pwm_config(chip, pwm, state->duty_cycle, state->period);
if (ret) {
if (enabled != curstate.enabled)
- pc->data->set_enable(chip, pwm, !enabled,
- state->polarity);
-
+ rockchip_pwm_enable(chip, pwm, !enabled,
+ state->polarity);
goto out;
}
- if (state->enabled != enabled)
- pc->data->set_enable(chip, pwm, state->enabled,
- state->polarity);
+ if (state->enabled != enabled) {
+ ret = rockchip_pwm_enable(chip, pwm, state->enabled,
+ state->polarity);
+ if (ret)
+ goto out;
+ }
/*
* Update the state with the real hardware, which can differ a bit
--
1.9.1
On Wed, Mar 01, 2017 at 07:10:55PM +0800, David Wu wrote:
> From: "david.wu" <[email protected]>
You might want to set up git to use the correct author.
> If the pwm was not enabled at uboot loader, pwm could not work for clock
> always disabled at pwm driver. The pwm clock is enabled at beginning of
> pwm_apply(), but disabled at end of pwm_apply().
>
> If the pwm was enabled at uboot loader, pwm clock is always enabled unless
> closed by ATF. The pwm-backlight might turn off the power at early suspend,
> should disable pwm clock for saving power consume.
>
> It is important to provide opportunity to enable/disable clock at pwm driver,
> the pwm consumer should ensure correct order to call pwm enable/disable, and
> pwm driver ensure state of pwm clock synchronized with pwm enabled state.
Please always use all-caps for abbreviations suchs as "PWM". I've fixed
up the commit message and applied this to for-4.11/fixes.
Thanks,
Thierry