On 10/16/24 02:56, AngeloGioacchino Del Regno wrote:
Il 16/10/24 11:26, Yassine Oudjana ha scritto:
On 02/03/2023 6:15 pm, AngeloGioacchino Del Regno wrote:
Il 02/03/23 13:40, Yassine Oudjana ha scritto:
From: Yassine Oudjana <y.oudjana@xxxxxxxxxxxxxx>
Add support for the watchdog timer/top reset generation unit found on MT6735.
Disable WDT_MODE_IRQ_EN in mtk_wdt_restart in order to make TOPRGU assert
the SYSRST pin instead of issuing an IRQ. This change may be needed in other
SoCs as well.
Signed-off-by: Yassine Oudjana <y.oudjana@xxxxxxxxxxxxxx>
---
drivers/watchdog/mtk_wdt.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
index a9c437598e7e..5a7a7b2b3727 100644
--- a/drivers/watchdog/mtk_wdt.c
+++ b/drivers/watchdog/mtk_wdt.c
@@ -10,6 +10,7 @@
*/
#include <dt-bindings/reset/mt2712-resets.h>
+#include <dt-bindings/reset/mediatek,mt6735-wdt.h>
#include <dt-bindings/reset/mediatek,mt6795-resets.h>
#include <dt-bindings/reset/mt7986-resets.h>
#include <dt-bindings/reset/mt8183-resets.h>
@@ -82,6 +83,10 @@ static const struct mtk_wdt_data mt2712_data = {
.toprgu_sw_rst_num = MT2712_TOPRGU_SW_RST_NUM,
};
+static const struct mtk_wdt_data mt6735_data = {
+ .toprgu_sw_rst_num = MT6735_TOPRGU_RST_NUM,
+};
+
static const struct mtk_wdt_data mt6795_data = {
.toprgu_sw_rst_num = MT6795_TOPRGU_SW_RST_NUM,
};
@@ -187,9 +192,15 @@ 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);
This is unnecessary and already done in mtk_wdt_start().
If you think you *require* this snippet, you most likely misconfigured the
devicetree node for your device :-)
Ok so mtk_wdt_start is never called.
mtk_wdt_init() says
if (readl(wdt_base + WDT_MODE) & WDT_MODE_EN) {
set_bit(WDOG_HW_RUNNING, &wdt_dev->status);
mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
}
Your bootloader starts the watchdog. This driver will set WDOG_HW_RUNNING and
will hence prevent calling the .start() callback - that's why.
FWIW, if the bootloader _doesn't_ start the watchdog, and the watchdog device
is never opened, the restart handler has to start the watchdog.
Guenter
