On Wed, 1 Mar 2017 18:16:02 +0800
David Wu <david.wu at rock-chips.com> wrote:
> From: "david.wu" <david.wu at rock-chips.com>
>
> 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: stable at vger.kernel.org
> Signed-off-by: David Wu <david.wu at rock-chips.com>
> Reviewed-by: Boris Brezillon <boris.brezillon at free-electrons.com>
> ---
> 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..dbee3c3 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 rk_pwm_enable(struct pwm_chip *chip,
> + struct pwm_device *pwm,
> + bool enable,
> + enum pwm_polarity polarity)
You didn't change the function name:
s/rk_pwm_enable/rockchip_pwm_enable/
> +{
> + 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 = rk_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);
> -
> + rk_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 = rk_pwm_enable(chip, pwm, state->enabled,
> + state->polarity);
> + if (ret)
> + goto out;
> + }
>
> /*
> * Update the state with the real hardware, which can differ a bit
