On Wed, Apr 10, 2024 at 04:40:39PM +0300, Claudiu wrote:
> From: Claudiu Beznea <[email protected]>
>
> There is no need to de-assert the reset signal on probe as the watchdog
> is not used prior executing start. Also, the clocks are not enabled in
> probe (pm_runtime_enable() doesn't do that), thus this is another indicator
> that the watchdog wasn't used previously like this. Instead, keep the
> watchdog hardware in its previous state at probe (by default it is in
> reset state), enable it when it is started and move it to reset state
> when it is stopped. This saves some extra power when the watchdog is
> unused.
>
> Signed-off-by: Claudiu Beznea <[email protected]>
Reviewed-by: Guenter Roeck <[email protected]>
> ---
>
> Changes in v8:
> - none
>
> Changes in v7:
> - none
>
> Changes in v6:
> - none
>
> Changes in v5:
> - update patch title
>
> Changes in v4:
> - none
>
> Changes in v3:
> - none
>
> Changes in v2:
> - none
>
> drivers/watchdog/rzg2l_wdt.c | 26 +++++++++++++++-----------
> 1 file changed, 15 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
> index 7bce093316c4..93a49fd0c7aa 100644
> --- a/drivers/watchdog/rzg2l_wdt.c
> +++ b/drivers/watchdog/rzg2l_wdt.c
> @@ -129,6 +129,10 @@ static int rzg2l_wdt_start(struct watchdog_device *wdev)
> if (ret)
> return ret;
>
> + ret = reset_control_deassert(priv->rstc);
> + if (ret)
> + return ret;
> +
> /* Initialize time out */
> rzg2l_wdt_init_timeout(wdev);
>
> @@ -146,7 +150,9 @@ static int rzg2l_wdt_stop(struct watchdog_device *wdev)
> struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
> int ret;
>
> - rzg2l_wdt_reset(priv);
> + ret = reset_control_assert(priv->rstc);
> + if (ret)
> + return ret;
>
> ret = pm_runtime_put(wdev->parent);
> if (ret < 0)
> @@ -186,6 +192,12 @@ static int rzg2l_wdt_restart(struct watchdog_device *wdev,
> clk_prepare_enable(priv->osc_clk);
>
> if (priv->devtype == WDT_RZG2L) {
> + int ret;
> +
> + ret = reset_control_deassert(priv->rstc);
> + if (ret)
> + return ret;
> +
> /* Generate Reset (WDTRSTB) Signal on parity error */
> rzg2l_wdt_write(priv, 0, PECR);
>
> @@ -236,13 +248,11 @@ static const struct watchdog_ops rzg2l_wdt_ops = {
> .restart = rzg2l_wdt_restart,
> };
>
> -static void rzg2l_wdt_reset_assert_pm_disable(void *data)
> +static void rzg2l_wdt_pm_disable(void *data)
> {
> struct watchdog_device *wdev = data;
> - struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
>
> pm_runtime_disable(wdev->parent);
> - reset_control_assert(priv->rstc);
> }
>
> static int rzg2l_wdt_probe(struct platform_device *pdev)
> @@ -285,10 +295,6 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
> return dev_err_probe(&pdev->dev, PTR_ERR(priv->rstc),
> "failed to get cpg reset");
>
> - ret = reset_control_deassert(priv->rstc);
> - if (ret)
> - return dev_err_probe(dev, ret, "failed to deassert");
> -
> priv->devtype = (uintptr_t)of_device_get_match_data(dev);
>
> if (priv->devtype == WDT_RZV2M) {
> @@ -309,9 +315,7 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
> priv->wdev.timeout = WDT_DEFAULT_TIMEOUT;
>
> watchdog_set_drvdata(&priv->wdev, priv);
> - ret = devm_add_action_or_reset(&pdev->dev,
> - rzg2l_wdt_reset_assert_pm_disable,
> - &priv->wdev);
> + ret = devm_add_action_or_reset(&pdev->dev, rzg2l_wdt_pm_disable, &priv->wdev);
> if (ret < 0)
> return ret;
>
> --
> 2.39.2
>