From 9b3461188e86f19113f57a71c8873fab6ca95f36 Mon Sep 17 00:00:00 2001 From: Paul Cercueil Date: Fri, 7 Jun 2019 18:24:27 +0200 Subject: [PATCH] watchdog: jz4740: Avoid starting watchdog in set_timeout Previously the jz4740_wdt_set_timeout() function was starting the timer unconditionally, even if it was stopped when that function was entered. Now, the timer will be restarted only if it was already running before this function is called. Signed-off-by: Paul Cercueil Reviewed-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/jz4740_wdt.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c index f1199db7bffa..d4a90916dd38 100644 --- a/drivers/watchdog/jz4740_wdt.c +++ b/drivers/watchdog/jz4740_wdt.c @@ -68,6 +68,7 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, unsigned int rtc_clk_rate; unsigned int timeout_value; unsigned short clock_div = JZ_WDT_CLOCK_DIV_1; + u8 tcer; rtc_clk_rate = clk_get_rate(drvdata->rtc_clk); @@ -83,6 +84,7 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, clock_div += (1 << TCU_TCSR_PRESCALE_LSB); } + tcer = readb(drvdata->base + TCU_REG_WDT_TCER); writeb(0x0, drvdata->base + TCU_REG_WDT_TCER); writew(clock_div, drvdata->base + TCU_REG_WDT_TCSR); @@ -90,7 +92,8 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, writew(0x0, drvdata->base + TCU_REG_WDT_TCNT); writew(clock_div | JZ_WDT_CLOCK_RTC, drvdata->base + TCU_REG_WDT_TCSR); - writeb(0x1, drvdata->base + TCU_REG_WDT_TCER); + if (tcer & TCU_WDT_TCER_TCEN) + writeb(TCU_WDT_TCER_TCEN, drvdata->base + TCU_REG_WDT_TCER); wdt_dev->timeout = new_timeout; return 0; @@ -98,9 +101,18 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, static int jz4740_wdt_start(struct watchdog_device *wdt_dev) { + struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); + u8 tcer; + + tcer = readb(drvdata->base + TCU_REG_WDT_TCER); + jz4740_timer_enable_watchdog(); jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout); + /* Start watchdog if it wasn't started already */ + if (!(tcer & TCU_WDT_TCER_TCEN)) + writeb(TCU_WDT_TCER_TCEN, drvdata->base + TCU_REG_WDT_TCER); + return 0; }