Messages in this thread | | | Date | Sun, 16 Jul 2023 16:17:29 +0300 | Subject | Re: [PATCH v6] pwm: atmel: Enable clk when pwm already enabled in bootloader | From | claudiu beznea <> |
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On 16.07.2023 05:06, Guiting Shen wrote: > The driver would never call clk_enable() if the PWM channel was already > enabled in bootloader which lead to dump the warning message "the PWM > clock already disabled" when turning off the PWM channel. > > Add atmel_pwm_enable_clk_if_on() in probe function to enable clock if > the PWM channel was already enabled in bootloader. > > Signed-off-by: Guiting Shen <aarongt.shen@gmail.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>
> --- > drivers/pwm/pwm-atmel.c | 47 +++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 45 insertions(+), 2 deletions(-) > > diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c > index cdbc23649032..fc89282db645 100644 > --- a/drivers/pwm/pwm-atmel.c > +++ b/drivers/pwm/pwm-atmel.c > @@ -36,7 +36,7 @@ > #define PWM_SR 0x0C > #define PWM_ISR 0x1C > /* Bit field in SR */ > -#define PWM_SR_ALL_CH_ON 0x0F > +#define PWM_SR_ALL_CH_MASK 0x0F > > /* The following register is PWM channel related registers */ > #define PWM_CH_REG_OFFSET 0x200 > @@ -464,6 +464,42 @@ static const struct of_device_id atmel_pwm_dt_ids[] = { > }; > MODULE_DEVICE_TABLE(of, atmel_pwm_dt_ids); > > +static int atmel_pwm_enable_clk_if_on(struct atmel_pwm_chip *atmel_pwm, bool on) > +{ > + unsigned int i, cnt = 0; > + int ret = 0; > + u32 sr; > + > + sr = atmel_pwm_readl(atmel_pwm, PWM_SR) & PWM_SR_ALL_CH_MASK; > + if (!sr) > + return 0; > + > + cnt = bitmap_weight((unsigned long *)&sr, atmel_pwm->chip.npwm); > + > + if (!on) > + goto disable_clk; > + > + for (i = 0; i < cnt; i++) { > + ret = clk_enable(atmel_pwm->clk); > + if (ret) { > + dev_err(atmel_pwm->chip.dev, > + "failed to enable clock for pwm %pe\n", > + ERR_PTR(ret)); > + > + cnt = i; > + goto disable_clk; > + } > + } > + > + return 0; > + > +disable_clk: > + while (cnt--) > + clk_disable(atmel_pwm->clk); > + > + return ret; > +} > + > static int atmel_pwm_probe(struct platform_device *pdev) > { > struct atmel_pwm_chip *atmel_pwm; > @@ -496,16 +532,23 @@ static int atmel_pwm_probe(struct platform_device *pdev) > atmel_pwm->chip.ops = &atmel_pwm_ops; > atmel_pwm->chip.npwm = 4; > > + ret = atmel_pwm_enable_clk_if_on(atmel_pwm, true); > + if (ret < 0) > + goto unprepare_clk; > + > ret = pwmchip_add(&atmel_pwm->chip); > if (ret < 0) { > dev_err(&pdev->dev, "failed to add PWM chip %d\n", ret); > - goto unprepare_clk; > + goto disable_clk; > } > > platform_set_drvdata(pdev, atmel_pwm); > > return ret; > > +disable_clk: > + atmel_pwm_enable_clk_if_on(atmel_pwm, false); > + > unprepare_clk: > clk_unprepare(atmel_pwm->clk); > return ret;
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