Hi,
On 20-07-23 10:43, Horia Geantă wrote:
> From: André Draszik <git@xxxxxxxxxx>
>
> At the moment, enabling this driver without the SNVS RTC driver
> being active will hang the kernel as soon as the power button
> is pressed.
>
> The reason is that in that case the SNVS isn't enabled, and
> any attempt to read the SNVS registers will simply hang forever.
>
> Ensure the clock is enabled (during the interrupt handler) to
> make this driver work.
>
> Also see commit 7f8993995410 ("drivers/rtc/rtc-snvs: add clock support")
> and commit edb190cb1734
> ("rtc: snvs: make sure clock is enabled for interrupt handle")
> for similar updates to the snvs rtc driver.
>
> Signed-off-by: André Draszik <git@xxxxxxxxxx>
> Reviewed-by: Horia Geantă <horia.geanta@xxxxxxx>
> Signed-off-by: Horia Geantă <horia.geanta@xxxxxxx>
> ---
> drivers/input/keyboard/snvs_pwrkey.c | 28 +++++++++++++++++++++++++++-
> 1 file changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/input/keyboard/snvs_pwrkey.c b/drivers/input/keyboard/snvs_pwrkey.c
> index 2f5e3ab5ed63..382d2ae82c9b 100644
> --- a/drivers/input/keyboard/snvs_pwrkey.c
> +++ b/drivers/input/keyboard/snvs_pwrkey.c
> @@ -16,6 +16,7 @@
> #include <linux/of_address.h>
> #include <linux/platform_device.h>
> #include <linux/pm_wakeirq.h>
> +#include <linux/clk.h>
> #include <linux/mfd/syscon.h>
> #include <linux/regmap.h>
>
> @@ -38,6 +39,7 @@ struct pwrkey_drv_data {
> int wakeup;
> struct timer_list check_timer;
> struct input_dev *input;
> + struct clk *clk;
> u8 minor_rev;
> };
>
> @@ -47,7 +49,10 @@ static void imx_imx_snvs_check_for_events(struct timer_list *t)
> struct input_dev *input = pdata->input;
> u32 state;
>
> + clk_enable(pdata->clk);
> regmap_read(pdata->snvs, SNVS_HPSR_REG, &state);
> + clk_disable(pdata->clk);
> +
> state = state & SNVS_HPSR_BTN ? 1 : 0;
>
> /* only report new event if status changed */
> @@ -74,11 +79,13 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
>
> pm_wakeup_event(input->dev.parent, 0);
>
> + clk_enable(pdata->clk);
> +
> regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
> if (lp_status & SNVS_LPSR_SPO) {
> if (pdata->minor_rev == 0) {
> /*
> - * The first generation i.MX6 SoCs only sends an
> + * The first generation i.MX[6|7] SoCs only send an
> * interrupt on button release. To mimic power-key
> * usage, we'll prepend a press event.
> */
> @@ -96,6 +103,8 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
> /* clear SPO status */
> regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
>
> + clk_disable(pdata->clk);
I'm not so happy about clk_enable/disable() during the interrupt
routine since those routines should be handled fast. Since we assume
that the clock is always on I would rather call clk_prepare_enable()
during probe() and keep the clock on.
> +
> return IRQ_HANDLED;
> }
>
> @@ -140,6 +149,23 @@ static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
> if (pdata->irq < 0)
> return -EINVAL;
>
> + pdata->clk = devm_clk_get_optional(&pdev->dev, "snvs-pwrkey");
> + if (IS_ERR(pdata->clk))
> + return PTR_ERR(pdata->clk);
> +
> + error = clk_prepare(pdata->clk);
> + if (error) {
> + dev_err(&pdev->dev, "failed to prepare the snvs clock\n");
> + return error;
> + }
> + error = devm_add_action_or_reset(&pdev->dev,
> + (void(*)(void *))clk_unprepare,
> + pdata->clk);
I'm not a fan about those casts. However, the intentation should be
fixed.
Regards,
Marco
> + if (error) {
> + dev_err(&pdev->dev, "failed to add reset action on 'snvs-pwrkey'");
> + return error;
> + }
> +
> regmap_read(pdata->snvs, SNVS_HPVIDR1_REG, &vid);
> pdata->minor_rev = vid & 0xff;
