On 5/8/22 12:43, Jonathan Neuschäfer wrote:
On the Nuvoton WPCM450 SoC, with its upcoming clock driver, peripheral clocks are individually gated and ungated. Therefore, the watchdog driver must be able to ungate the watchdog clock. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@xxxxxxx> --- v3: - Add enable/disable calls to npcm_wdt_restart handler - Not applied due to the above change: Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx> v2: - https://lore.kernel.org/lkml/20220429172030.398011-4-j.neuschaefer@xxxxxxx/ - Add clk_disable_unprepare call, suggested by Guenter Roeck v1: - https://lore.kernel.org/lkml/20220422183012.444674-4-j.neuschaefer@xxxxxxx/ --- drivers/watchdog/npcm_wdt.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/watchdog/npcm_wdt.c b/drivers/watchdog/npcm_wdt.c index 28a24caa2627c..a1240a906ef2a 100644 --- a/drivers/watchdog/npcm_wdt.c +++ b/drivers/watchdog/npcm_wdt.c @@ -3,6 +3,7 @@ // Copyright (c) 2018 IBM Corp. #include <linux/bitops.h> +#include <linux/clk.h> #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/kernel.h> @@ -43,6 +44,7 @@ struct npcm_wdt { struct watchdog_device wdd; void __iomem *reg; + struct clk *clk; }; static inline struct npcm_wdt *to_npcm_wdt(struct watchdog_device *wdd) @@ -66,6 +68,9 @@ static int npcm_wdt_start(struct watchdog_device *wdd) struct npcm_wdt *wdt = to_npcm_wdt(wdd); u32 val; + if (wdt->clk) + clk_prepare_enable(wdt->clk); + if (wdd->timeout < 2) val = 0x800; else if (wdd->timeout < 3) @@ -100,6 +105,9 @@ static int npcm_wdt_stop(struct watchdog_device *wdd) writel(0, wdt->reg); + if (wdt->clk) + clk_disable_unprepare(wdt->clk); + return 0; } @@ -147,9 +155,15 @@ static int npcm_wdt_restart(struct watchdog_device *wdd, { struct npcm_wdt *wdt = to_npcm_wdt(wdd); + if (wdt->clk) + clk_prepare_enable(wdt->clk); + writel(NPCM_WTR | NPCM_WTRE | NPCM_WTE, wdt->reg); udelay(1000); + if (wdt->clk) + clk_disable_unprepare(wdt->clk); +
I am trying to understand why you stop the clock here. If the watchdog didn't reset the system by now, for whatever reason, you explicitly don't want it to reset the system ? If so, please add a comment describing the reason for stopping the clock here. Thanks, Guenter
return 0; } @@ -191,6 +205,10 @@ static int npcm_wdt_probe(struct platform_device *pdev) if (IS_ERR(wdt->reg)) return PTR_ERR(wdt->reg); + wdt->clk = devm_clk_get_optional(&pdev->dev, NULL); + if (IS_ERR(wdt->clk)) + return PTR_ERR(wdt->clk); + irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; -- 2.35.1
