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authorWolfram Sang <wsa+renesas@sang-engineering.com>2017-07-19 10:27:55 +0200
committerWim Van Sebroeck <wim@iguana.be>2017-09-09 20:23:24 +0200
commit03a196f25f5652a3deffc1b8eade8a3c1c39282c (patch)
treedaef7ae9ab99d622a09ad0747a08cbcd31a45438 /drivers/watchdog/renesas_wdt.c
parentwatchdog: renesas_wdt: apply better precision (diff)
downloadlinux-03a196f25f5652a3deffc1b8eade8a3c1c39282c.tar.xz
linux-03a196f25f5652a3deffc1b8eade8a3c1c39282c.zip
watchdog: renesas_wdt: add another divider option
If we set RWTCSRB to 0, we can gain 4096 as another divider value. This is supported by all R-Car Gen2 and Gen3 devices which we aim to support. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/renesas_wdt.c')
-rw-r--r--drivers/watchdog/renesas_wdt.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c
index 599ba5aaa053..e3f204bb8802 100644
--- a/drivers/watchdog/renesas_wdt.c
+++ b/drivers/watchdog/renesas_wdt.c
@@ -23,21 +23,22 @@
#define RWTCSRA_WOVF BIT(4)
#define RWTCSRA_WRFLG BIT(5)
#define RWTCSRA_TME BIT(7)
+#define RWTCSRB 8
#define RWDT_DEFAULT_TIMEOUT 60U
/*
* In probe, clk_rate is checked to be not more than 16 bit * biggest clock
- * divider (10 bits). d is only a factor to fully utilize the WDT counter and
+ * divider (12 bits). d is only a factor to fully utilize the WDT counter and
* will not exceed its 16 bits. Thus, no overflow, we stay below 32 bits.
*/
#define MUL_BY_CLKS_PER_SEC(p, d) \
DIV_ROUND_UP((d) * (p)->clk_rate, clk_divs[(p)->cks])
-/* d is 16 bit, clk_divs 10 bit -> no 32 bit overflow */
+/* d is 16 bit, clk_divs 12 bit -> no 32 bit overflow */
#define DIV_BY_CLKS_PER_SEC(p, d) ((d) * clk_divs[(p)->cks] / (p)->clk_rate)
-static const unsigned int clk_divs[] = { 1, 4, 16, 32, 64, 128, 1024 };
+static const unsigned int clk_divs[] = { 1, 4, 16, 32, 64, 128, 1024, 4096 };
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
@@ -77,6 +78,7 @@ static int rwdt_start(struct watchdog_device *wdev)
clk_prepare_enable(priv->clk);
+ rwdt_write(priv, 0, RWTCSRB);
rwdt_write(priv, priv->cks, RWTCSRA);
rwdt_init_timeout(wdev);