diff mbox series

[v4,2/6] watchdog: npcm: Enable clock if provided

Message ID 20220610072141.347795-3-j.neuschaefer@gmx.net
State New
Headers show
Series Nuvoton WPCM450 clock and reset driver | expand

Commit Message

J. Neuschäfer June 10, 2022, 7:21 a.m. UTC 
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@gmx.net>
---

v4:
- Don't disable clock in npcm_wdt_restart function

v3:
- https://lore.kernel.org/lkml/20220508194333.2170161-4-j.neuschaefer@gmx.net/
- Add enable/disable calls to npcm_wdt_restart handler
- Not applied due to the above change:  Acked-by: Guenter Roeck <linux@roeck-us.net>

v2:
- https://lore.kernel.org/lkml/20220429172030.398011-4-j.neuschaefer@gmx.net/
- Add clk_disable_unprepare call, suggested by Guenter Roeck

v1:
- https://lore.kernel.org/lkml/20220422183012.444674-4-j.neuschaefer@gmx.net/
---
 drivers/watchdog/npcm_wdt.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

--
2.35.1
diff mbox series

Patch

diff --git a/drivers/watchdog/npcm_wdt.c b/drivers/watchdog/npcm_wdt.c
index 28a24caa2627c..a5dd1c2301374 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;
 }

@@ -147,6 +155,10 @@  static int npcm_wdt_restart(struct watchdog_device *wdd,
 {
 	struct npcm_wdt *wdt = to_npcm_wdt(wdd);

+	/* For reset, we start the WDT clock and leave it running. */
+	if (wdt->clk)
+		clk_prepare_enable(wdt->clk);
+
 	writel(NPCM_WTR | NPCM_WTRE | NPCM_WTE, wdt->reg);
 	udelay(1000);

@@ -191,6 +203,10 @@  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;