2022-05-01 08:43:01

by Jonathan Neuschäfer

Subject: [PATCH v2 3/7] watchdog: npcm: Enable clock if provided

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 <[email protected]>
---

v2:
- Add clk_disable_unprepare call, suggested by Guenter Roeck

v1:
- https://lore.kernel.org/lkml/[email protected]/
---
drivers/watchdog/npcm_wdt.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/watchdog/npcm_wdt.c b/drivers/watchdog/npcm_wdt.c
index 28a24caa2627c..ee08d9805f966 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;
}

@@ -191,6 +199,10 @@ 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

2022-05-02 23:27:28

by Guenter Roeck

Subject: Re: [PATCH v2 3/7] watchdog: npcm: Enable clock if provided

On 4/29/22 10:20, 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 <[email protected]>

Acked-by: Guenter Roeck <[email protected]>

> ---
>
> v2:
> - Add clk_disable_unprepare call, suggested by Guenter Roeck
>
> v1:
> - https://lore.kernel.org/lkml/[email protected]/
> ---
> drivers/watchdog/npcm_wdt.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/watchdog/npcm_wdt.c b/drivers/watchdog/npcm_wdt.c
> index 28a24caa2627c..ee08d9805f966 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;
> }
>
> @@ -191,6 +199,10 @@ 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
>