[v2,0/2] MediaTek MT6735 TOPRGU/WDT support

These patches are part of a larger effort to support the MT6735 SoC family
in mainline Linux. More patches (unsent or sent and pending review or
revision) can be found here[1].

This series adds support for the top reset generation unit (TOPRGU) found
on the MediaTek MT6735 SoC. TOPRGU generates several reset signals and
provides watchdog timer functionality.

While doing so, a fix is made to the restart handler to make it work even
when the watchdog is disabled by default (never enabled by the bootloader).

[1] https://gitlab.com/mt6735-mainline/linux/-/commits/mt6735-staging

Changes since v1:
- Split restart handler fix and MT6735 support into separate patches.

Yassine Oudjana (2):
  watchdog: mediatek: Fix mtk_wdt_restart
  watchdog: mediatek: Add support for MT6735 TOPRGU/WDT

 drivers/watchdog/mtk_wdt.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Il 06/11/24 11:47, Yassine Oudjana ha scritto:
> Clear the IRQ enable bit of WDT_MODE before asserting software reset
> in order to make TOPRGU issue a system reset signal instead of an IRQ.
> 
> Fixes: a44a45536f7b ("watchdog: Add driver for Mediatek watchdog")
> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>

I'd be more comfortable with a title like:

watchdog: mediatek: Make sure system reset gets asserted in mtk_wdt_restart()

or along those lines, saying what's this commit about, because a generic
"fix" doesn't really mean anything...

About the commit description - that's good.
Btw, I wonder if maintainers can fix the title without you sending a v3...

Anyway - you can get my:

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Cheers!
Angelo

> ---
>   drivers/watchdog/mtk_wdt.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> index c35f85ce8d69c..e2d7a57d6ea2e 100644
> --- a/drivers/watchdog/mtk_wdt.c
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -225,9 +225,15 @@ static int mtk_wdt_restart(struct watchdog_device *wdt_dev,
>   {
>   	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
>   	void __iomem *wdt_base;
> +	u32 reg;
>   
>   	wdt_base = mtk_wdt->wdt_base;
>   
> +	/* Enable reset in order to issue a system reset instead of an IRQ */
> +	reg = readl(wdt_base + WDT_MODE);
> +	reg &= ~WDT_MODE_IRQ_EN;
> +	writel(reg | WDT_MODE_KEY, wdt_base + WDT_MODE);
> +
>   	while (1) {
>   		writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST);
>   		mdelay(5);

On 11/6/24 02:47, Yassine Oudjana wrote:
> Clear the IRQ enable bit of WDT_MODE before asserting software reset
> in order to make TOPRGU issue a system reset signal instead of an IRQ.
> 
> Fixes: a44a45536f7b ("watchdog: Add driver for Mediatek watchdog")
> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>   drivers/watchdog/mtk_wdt.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> index c35f85ce8d69c..e2d7a57d6ea2e 100644
> --- a/drivers/watchdog/mtk_wdt.c
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -225,9 +225,15 @@ static int mtk_wdt_restart(struct watchdog_device *wdt_dev,
>   {
>   	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
>   	void __iomem *wdt_base;
> +	u32 reg;
>   
>   	wdt_base = mtk_wdt->wdt_base;
>   
> +	/* Enable reset in order to issue a system reset instead of an IRQ */
> +	reg = readl(wdt_base + WDT_MODE);
> +	reg &= ~WDT_MODE_IRQ_EN;
> +	writel(reg | WDT_MODE_KEY, wdt_base + WDT_MODE);
> +
>   	while (1) {
>   		writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST);
>   		mdelay(5);

Hi Angelo, Yassine,

> Il 06/11/24 11:47, Yassine Oudjana ha scritto:
> >Clear the IRQ enable bit of WDT_MODE before asserting software reset
> >in order to make TOPRGU issue a system reset signal instead of an IRQ.
> >
> >Fixes: a44a45536f7b ("watchdog: Add driver for Mediatek watchdog")
> >Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
> 
> I'd be more comfortable with a title like:
> 
> watchdog: mediatek: Make sure system reset gets asserted in mtk_wdt_restart()
> 
> or along those lines, saying what's this commit about, because a generic
> "fix" doesn't really mean anything...
> 
> About the commit description - that's good.
> Btw, I wonder if maintainers can fix the title without you sending a v3...

I added it into linux-watchdog-next and changed the commit description whiledoing that.

Kind regards,
Wim.

> 
> Anyway - you can get my:
> 
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> 
> Cheers!
> Angelo
> 
> >---
> >  drivers/watchdog/mtk_wdt.c | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> >diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> >index c35f85ce8d69c..e2d7a57d6ea2e 100644
> >--- a/drivers/watchdog/mtk_wdt.c
> >+++ b/drivers/watchdog/mtk_wdt.c
> >@@ -225,9 +225,15 @@ static int mtk_wdt_restart(struct watchdog_device *wdt_dev,
> >  {
> >  	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
> >  	void __iomem *wdt_base;
> >+	u32 reg;
> >  	wdt_base = mtk_wdt->wdt_base;
> >+	/* Enable reset in order to issue a system reset instead of an IRQ */
> >+	reg = readl(wdt_base + WDT_MODE);
> >+	reg &= ~WDT_MODE_IRQ_EN;
> >+	writel(reg | WDT_MODE_KEY, wdt_base + WDT_MODE);
> >+
> >  	while (1) {
> >  		writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST);
> >  		mdelay(5);
> 
>