[PATCH 2/4] watchdog: coh901327_wdt: Keep clock enabled after loading driver

From: Guenter Roeck
Date: Tue Jan 03 2017 - 22:26:12 EST


Enabling the clock before accessing chip registers and disabling it
afterwards does not really make sense and only adds complexity to
the driver. In addition to that, a comment int the driver suggests
that it does not serve a useful purpose either.

"The watchdog block is of course always clocked, the
clk_enable()/clk_disable() calls are mainly for performing reference
counting higher up in the clock hierarchy."

Just keep the clock enabled instead.

Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
drivers/watchdog/coh901327_wdt.c | 21 +--------------------
1 file changed, 1 insertion(+), 20 deletions(-)

diff --git a/drivers/watchdog/coh901327_wdt.c b/drivers/watchdog/coh901327_wdt.c
index dc97b2fd6c49..1385a920df4f 100644
--- a/drivers/watchdog/coh901327_wdt.c
+++ b/drivers/watchdog/coh901327_wdt.c
@@ -74,11 +74,6 @@ static int irq;
static void __iomem *virtbase;
static struct device *parent;

-/*
- * The watchdog block is of course always clocked, the
- * clk_enable()/clk_disable() calls are mainly for performing reference
- * counting higher up in the clock hierarchy.
- */
static struct clk *clk;

/*
@@ -90,7 +85,6 @@ static void coh901327_enable(u16 timeout)
unsigned long freq;
unsigned long delay_ns;

- clk_enable(clk);
/* Restart timer if it is disabled */
val = readw(virtbase + U300_WDOG_D2R);
if (val == U300_WDOG_D2R_DISABLE_STATUS_DISABLED)
@@ -118,7 +112,6 @@ static void coh901327_enable(u16 timeout)
*/
(void) readw(virtbase + U300_WDOG_CR);
val = readw(virtbase + U300_WDOG_D2R);
- clk_disable(clk);
if (val != U300_WDOG_D2R_DISABLE_STATUS_ENABLED)
dev_err(parent,
"%s(): watchdog not enabled! D2R value %04x\n",
@@ -129,7 +122,6 @@ static void coh901327_disable(void)
{
u16 val;

- clk_enable(clk);
/* Disable the watchdog interrupt if it is active */
writew(0x0000U, virtbase + U300_WDOG_IMR);
/* If the watchdog is currently enabled, attempt to disable it */
@@ -144,7 +136,6 @@ static void coh901327_disable(void)
virtbase + U300_WDOG_D2R);
}
val = readw(virtbase + U300_WDOG_D2R);
- clk_disable(clk);
if (val != U300_WDOG_D2R_DISABLE_STATUS_DISABLED)
dev_err(parent,
"%s(): watchdog not disabled! D2R value %04x\n",
@@ -165,11 +156,9 @@ static int coh901327_stop(struct watchdog_device *wdt_dev)

static int coh901327_ping(struct watchdog_device *wdd)
{
- clk_enable(clk);
/* Feed the watchdog */
writew(U300_WDOG_FR_FEED_RESTART_TIMER,
virtbase + U300_WDOG_FR);
- clk_disable(clk);
return 0;
}

@@ -177,13 +166,11 @@ static int coh901327_settimeout(struct watchdog_device *wdt_dev,
unsigned int time)
{
wdt_dev->timeout = time;
- clk_enable(clk);
/* Set new timeout value */
writew(time * 100, virtbase + U300_WDOG_TR);
/* Feed the dog */
writew(U300_WDOG_FR_FEED_RESTART_TIMER,
virtbase + U300_WDOG_FR);
- clk_disable(clk);
return 0;
}

@@ -191,13 +178,11 @@ static unsigned int coh901327_gettimeleft(struct watchdog_device *wdt_dev)
{
u16 val;

- clk_enable(clk);
/* Read repeatedly until the value is stable! */
val = readw(virtbase + U300_WDOG_CR);
while (val & U300_WDOG_CR_VALID_IND)
val = readw(virtbase + U300_WDOG_CR);
val &= U300_WDOG_CR_COUNT_VALUE_MASK;
- clk_disable(clk);
if (val != 0)
val /= 100;

@@ -221,13 +206,11 @@ static irqreturn_t coh901327_interrupt(int irq, void *data)
* to prevent a watchdog reset by feeding the watchdog at this
* point.
*/
- clk_enable(clk);
val = readw(virtbase + U300_WDOG_IER);
if (val == U300_WDOG_IER_WILL_BARK_IRQ_EVENT_IND)
writew(U300_WDOG_IER_WILL_BARK_IRQ_ACK_ENABLE,
virtbase + U300_WDOG_IER);
writew(0x0000U, virtbase + U300_WDOG_IMR);
- clk_disable(clk);
dev_crit(parent, "watchdog is barking!\n");
return IRQ_HANDLED;
}
@@ -263,7 +246,7 @@ static int __exit coh901327_remove(struct platform_device *pdev)
watchdog_unregister_device(&coh901327_wdt);
coh901327_disable();
free_irq(irq, pdev);
- clk_unprepare(clk);
+ clk_disable_unprepare(clk);
clk_put(clk);
iounmap(virtbase);
release_mem_region(phybase, physize);
@@ -352,8 +335,6 @@ static int __init coh901327_probe(struct platform_device *pdev)
goto out_no_irq;
}

- clk_disable(clk);
-
ret = watchdog_init_timeout(&coh901327_wdt, margin, &pdev->dev);
if (ret < 0)
coh901327_wdt.timeout = 60;
--
2.7.4