On Tue, 5 Feb 2019 13:40:29 +0100
Fabrice Gasnier <fabrice.gasnier@xxxxxx> wrote:
> Add suspend/resume PM sleep ops. When going to low power, disable
> active counter. Only active counter should be resumed: don't touch
> disabled counter, as it may be used by other LPTimer MFD child driver.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
I think this looks fine. I'm not totally sure if patches 3,4 are
separable from 1,2 though so please let me know whether I should take
these now, or let all 4 go in together via some path?
Thanks,
Jonathan
> ---
> drivers/iio/counter/stm32-lptimer-cnt.c | 55 +++++++++++++++++++++++++++++++++
> 1 file changed, 55 insertions(+)
>
> diff --git a/drivers/iio/counter/stm32-lptimer-cnt.c b/drivers/iio/counter/stm32-lptimer-cnt.c
> index 42fb8ba..2a49cce 100644
> --- a/drivers/iio/counter/stm32-lptimer-cnt.c
> +++ b/drivers/iio/counter/stm32-lptimer-cnt.c
> @@ -14,6 +14,7 @@
> #include <linux/iio/iio.h>
> #include <linux/mfd/stm32-lptimer.h>
> #include <linux/module.h>
> +#include <linux/pinctrl/consumer.h>
> #include <linux/platform_device.h>
>
> struct stm32_lptim_cnt {
> @@ -23,6 +24,7 @@ struct stm32_lptim_cnt {
> u32 preset;
> u32 polarity;
> u32 quadrature_mode;
> + bool enabled;
> };
>
> static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv)
> @@ -50,6 +52,7 @@ static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv,
>
> if (!enable) {
> clk_disable(priv->clk);
> + priv->enabled = false;
> return 0;
> }
>
> @@ -79,6 +82,7 @@ static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv,
> regmap_write(priv->regmap, STM32_LPTIM_CR, 0);
> return ret;
> }
> + priv->enabled = true;
>
> /* Start LP timer in continuous mode */
> return regmap_update_bits(priv->regmap, STM32_LPTIM_CR,
> @@ -361,6 +365,56 @@ static int stm32_lptim_cnt_probe(struct platform_device *pdev)
> return devm_iio_device_register(&pdev->dev, indio_dev);
> }
>
> +#ifdef CONFIG_PM_SLEEP
> +static int stm32_lptim_cnt_suspend(struct device *dev)
> +{
> + struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
> + int ret;
> +
> + /* Only take care of enabled counter: don't disturb other MFD child */
> + if (priv->enabled) {
> + ret = stm32_lptim_setup(priv, 0);
> + if (ret)
> + return ret;
> +
> + ret = stm32_lptim_set_enable_state(priv, 0);
> + if (ret)
> + return ret;
> +
> + /* Force enable state for later resume */
> + priv->enabled = true;
> + }
> +
> + return pinctrl_pm_select_sleep_state(dev);
> +}
> +
> +static int stm32_lptim_cnt_resume(struct device *dev)
> +{
> + struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = pinctrl_pm_select_default_state(dev);
> + if (ret)
> + return ret;
> +
> + if (priv->enabled) {
> + priv->enabled = false;
> + ret = stm32_lptim_setup(priv, 1);
> + if (ret)
> + return ret;
> +
> + ret = stm32_lptim_set_enable_state(priv, 1);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(stm32_lptim_cnt_pm_ops, stm32_lptim_cnt_suspend,
> + stm32_lptim_cnt_resume);
> +
> static const struct of_device_id stm32_lptim_cnt_of_match[] = {
> { .compatible = "st,stm32-lptimer-counter", },
> {},
> @@ -372,6 +426,7 @@ static int stm32_lptim_cnt_probe(struct platform_device *pdev)
> .driver = {
> .name = "stm32-lptimer-counter",
> .of_match_table = stm32_lptim_cnt_of_match,
> + .pm = &stm32_lptim_cnt_pm_ops,
> },
> };
> module_platform_driver(stm32_lptim_cnt_driver);
