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pwm: rockchip: State of pwm clock should synchronize with pwm enabled state

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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.

Change-Id: I545db81eb638957567abacb93fd06fff9dd7181b
Fixes: 2bf1c98aa5 ("pwm: rockchip: Add support for atomic update")
Signed-off-by: David Wu <david.wu@rock-chips.com>
This commit is contained in:
david.wu
2017-02-28 11:23:34 +08:00
committed by Huang, Tao
parent 22f81326b5
commit 00537de90c
1 changed files with 40 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

63
drivers/pwm/pwm-rockchip.c
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@@ -148,7 +148,7 @@ static void rockchip_pwm_get_state(struct pwm_chip *chip,
u64 tmp;
int ret;
ret = clk_enable(pc->clk);
ret = clk_enable(pc->pclk);
if (ret)
return;
@@ -164,7 +164,7 @@ static void rockchip_pwm_get_state(struct pwm_chip *chip,
pc->data->get_state(chip, pwm, state);
clk_disable(pc->clk);
clk_disable(pc->pclk);
}
static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -203,6 +203,28 @@ 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)
{
@@ -218,27 +240,27 @@ static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
if (ret)
return ret;
ret = clk_enable(pc->clk);
if (ret)
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
@@ -247,7 +269,6 @@ static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
rockchip_pwm_get_state(chip, pwm, state);
out:
clk_disable(pc->clk);
clk_disable(pc->pclk);
return ret;
@@ -360,11 +381,11 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
ret = clk_prepare_enable(pc->clk);
if (ret) {
dev_err(&pdev->dev, "Can't prepare bus clk: %d\n", ret);
dev_err(&pdev->dev, "Can't prepare enable bus clk: %d\n", ret);
return ret;
}
ret = clk_prepare_enable(pc->pclk);
ret = clk_prepare(pc->pclk);
if (ret) {
dev_err(&pdev->dev, "Can't prepare periph clk: %d\n", ret);
goto err_clk;
@@ -391,17 +412,15 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
}
/* Keep the PWM clk enabled if the PWM appears to be up and running. */
if (!pwm_is_enabled(pc->chip.pwms)) {
clk_disable(pc->pclk);
if (!pwm_is_enabled(pc->chip.pwms))
clk_disable(pc->clk);
}
return 0;
err_pclk:
clk_unprepare(pc->pclk);
err_clk:
clk_unprepare(pc->clk);
clk_disable_unprepare(pc->clk);
return ret;
}
@@ -421,10 +440,8 @@ static int rockchip_pwm_remove(struct platform_device *pdev)
* clk_unprepare() after pwmchip_remove().
*
*/
if (pwm_is_enabled(pc->chip.pwms)) {
clk_disable(pc->pclk);
if (pwm_is_enabled(pc->chip.pwms))
clk_disable(pc->clk);
}
clk_unprepare(pc->pclk);
clk_unprepare(pc->clk);