[PATCH v5 04/20] watchdog: orion: Use atomic access for shared registers
Ezequiel Garcia
ezequiel.garcia at free-electrons.com
Mon Jan 27 10:27:04 EST 2014
Since the timer control register is shared with the clocksource driver,
use the recently introduced atomic_io_clear_set() to access such register.
Given the watchdog core already provides serialization for all the
watchdog ops, this commit allows to remove the spinlock entirely.
Reviewed-by: Guenter Roeck <linux at roeck-us.net>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia at free-electrons.com>
---
drivers/watchdog/orion_wdt.c | 42 +++++-------------------------------------
1 file changed, 5 insertions(+), 37 deletions(-)
diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c
index 7f19fa3..b92a991 100644
--- a/drivers/watchdog/orion_wdt.c
+++ b/drivers/watchdog/orion_wdt.c
@@ -20,7 +20,6 @@
#include <linux/watchdog.h>
#include <linux/init.h>
#include <linux/io.h>
-#include <linux/spinlock.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/of.h>
@@ -46,25 +45,16 @@ static unsigned int wdt_max_duration; /* (seconds) */
static struct clk *clk;
static unsigned int wdt_tclk;
static void __iomem *wdt_reg;
-static DEFINE_SPINLOCK(wdt_lock);
static int orion_wdt_ping(struct watchdog_device *wdt_dev)
{
- spin_lock(&wdt_lock);
-
/* Reload watchdog duration */
writel(wdt_tclk * wdt_dev->timeout, wdt_reg + WDT_VAL);
-
- spin_unlock(&wdt_lock);
return 0;
}
static int orion_wdt_start(struct watchdog_device *wdt_dev)
{
- u32 reg;
-
- spin_lock(&wdt_lock);
-
/* Set watchdog duration */
writel(wdt_tclk * wdt_dev->timeout, wdt_reg + WDT_VAL);
@@ -72,48 +62,26 @@ static int orion_wdt_start(struct watchdog_device *wdt_dev)
writel(~WDT_INT_REQ, BRIDGE_CAUSE);
/* Enable watchdog timer */
- reg = readl(wdt_reg + TIMER_CTRL);
- reg |= WDT_EN;
- writel(reg, wdt_reg + TIMER_CTRL);
+ atomic_io_modify(wdt_reg + TIMER_CTRL, WDT_EN, WDT_EN);
/* Enable reset on watchdog */
- reg = readl(RSTOUTn_MASK);
- reg |= WDT_RESET_OUT_EN;
- writel(reg, RSTOUTn_MASK);
-
- spin_unlock(&wdt_lock);
+ atomic_io_modify(RSTOUTn_MASK, WDT_RESET_OUT_EN, WDT_RESET_OUT_EN);
return 0;
}
static int orion_wdt_stop(struct watchdog_device *wdt_dev)
{
- u32 reg;
-
- spin_lock(&wdt_lock);
-
/* Disable reset on watchdog */
- reg = readl(RSTOUTn_MASK);
- reg &= ~WDT_RESET_OUT_EN;
- writel(reg, RSTOUTn_MASK);
+ atomic_io_modify(RSTOUTn_MASK, WDT_RESET_OUT_EN, 0);
/* Disable watchdog timer */
- reg = readl(wdt_reg + TIMER_CTRL);
- reg &= ~WDT_EN;
- writel(reg, wdt_reg + TIMER_CTRL);
-
- spin_unlock(&wdt_lock);
+ atomic_io_modify(wdt_reg + TIMER_CTRL, WDT_EN, 0);
return 0;
}
static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
{
- unsigned int time_left;
-
- spin_lock(&wdt_lock);
- time_left = readl(wdt_reg + WDT_VAL) / wdt_tclk;
- spin_unlock(&wdt_lock);
-
- return time_left;
+ return readl(wdt_reg + WDT_VAL) / wdt_tclk;
}
static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
--
1.8.1.5
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