On 15/09/2017 at 16:04, Romain Izard wrote:
> Save and restore registers for the PWM on suspend and resume, which
> makes hibernation and backup modes possible.
> 
> Signed-off-by: Romain Izard <romain.izard....@gmail.com>

Seems good to me:
Acked-by: Nicolas Ferre <nicolas.fe...@microchip.com>

> ---
>  drivers/pwm/pwm-atmel-tcb.c | 63 
> +++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 61 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-atmel-tcb.c b/drivers/pwm/pwm-atmel-tcb.c
> index 75db585a2a94..acd3ce8ecf3f 100644
> --- a/drivers/pwm/pwm-atmel-tcb.c
> +++ b/drivers/pwm/pwm-atmel-tcb.c
> @@ -37,11 +37,20 @@ struct atmel_tcb_pwm_device {
>       unsigned period;                /* PWM period expressed in clk cycles */
>  };
>  
> +struct atmel_tcb_channel {
> +     u32 enabled;
> +     u32 cmr;
> +     u32 ra;
> +     u32 rb;
> +     u32 rc;
> +};
> +
>  struct atmel_tcb_pwm_chip {
>       struct pwm_chip chip;
>       spinlock_t lock;
>       struct atmel_tc *tc;
>       struct atmel_tcb_pwm_device *pwms[NPWM];
> +     struct atmel_tcb_channel bkup[NPWM / 2];
>  };
>  
>  static inline struct atmel_tcb_pwm_chip *to_tcb_chip(struct pwm_chip *chip)
> @@ -175,12 +184,15 @@ static void atmel_tcb_pwm_disable(struct pwm_chip 
> *chip, struct pwm_device *pwm)
>        * Use software trigger to apply the new setting.
>        * If both PWM devices in this group are disabled we stop the clock.
>        */
> -     if (!(cmr & (ATMEL_TC_ACPC | ATMEL_TC_BCPC)))
> +     if (!(cmr & (ATMEL_TC_ACPC | ATMEL_TC_BCPC))) {
>               __raw_writel(ATMEL_TC_SWTRG | ATMEL_TC_CLKDIS,
>                            regs + ATMEL_TC_REG(group, CCR));
> -     else
> +             tcbpwmc->bkup[group].enabled = 1;
> +     } else {
>               __raw_writel(ATMEL_TC_SWTRG, regs +
>                            ATMEL_TC_REG(group, CCR));
> +             tcbpwmc->bkup[group].enabled = 0;
> +     }
>  
>       spin_unlock(&tcbpwmc->lock);
>  }
> @@ -263,6 +275,7 @@ static int atmel_tcb_pwm_enable(struct pwm_chip *chip, 
> struct pwm_device *pwm)
>       /* Use software trigger to apply the new setting */
>       __raw_writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
>                    regs + ATMEL_TC_REG(group, CCR));
> +     tcbpwmc->bkup[group].enabled = 1;
>       spin_unlock(&tcbpwmc->lock);
>       return 0;
>  }
> @@ -445,10 +458,56 @@ static const struct of_device_id atmel_tcb_pwm_dt_ids[] 
> = {
>  };
>  MODULE_DEVICE_TABLE(of, atmel_tcb_pwm_dt_ids);
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int atmel_tcb_pwm_suspend(struct device *dev)
> +{
> +     struct platform_device *pdev = to_platform_device(dev);
> +     struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev);
> +     void __iomem *base = tcbpwm->tc->regs;
> +     int i;
> +
> +     for (i = 0; i < (NPWM / 2); i++) {
> +             struct atmel_tcb_channel *chan = &tcbpwm->bkup[i];
> +
> +             chan->cmr = readl(base + ATMEL_TC_REG(i, CMR));
> +             chan->ra = readl(base + ATMEL_TC_REG(i, RA));
> +             chan->rb = readl(base + ATMEL_TC_REG(i, RB));
> +             chan->rc = readl(base + ATMEL_TC_REG(i, RC));
> +     }
> +     return 0;
> +}
> +
> +static int atmel_tcb_pwm_resume(struct device *dev)
> +{
> +     struct platform_device *pdev = to_platform_device(dev);
> +     struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev);
> +     void __iomem *base = tcbpwm->tc->regs;
> +     int i;
> +
> +     for (i = 0; i < (NPWM / 2); i++) {
> +             struct atmel_tcb_channel *chan = &tcbpwm->bkup[i];
> +
> +             writel(chan->cmr, base + ATMEL_TC_REG(i, CMR));
> +             writel(chan->ra, base + ATMEL_TC_REG(i, RA));
> +             writel(chan->rb, base + ATMEL_TC_REG(i, RB));
> +             writel(chan->rc, base + ATMEL_TC_REG(i, RC));
> +             if (chan->enabled) {
> +                     writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
> +                             base + ATMEL_TC_REG(i, CCR));
> +             }
> +     }
> +     return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(atmel_tcb_pwm_pm_ops, atmel_tcb_pwm_suspend,
> +                      atmel_tcb_pwm_resume);
> +
>  static struct platform_driver atmel_tcb_pwm_driver = {
>       .driver = {
>               .name = "atmel-tcb-pwm",
>               .of_match_table = atmel_tcb_pwm_dt_ids,
> +             .pm = &atmel_tcb_pwm_pm_ops,
>       },
>       .probe = atmel_tcb_pwm_probe,
>       .remove = atmel_tcb_pwm_remove,
> 


-- 
Nicolas Ferre
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