From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jjQqi-0004F7-28 for barebox@lists.infradead.org; Thu, 11 Jun 2020 17:18:45 +0000 From: Ahmad Fatoum Date: Thu, 11 Jun 2020 19:18:38 +0200 Message-Id: <20200611171838.13876-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH] watchdog: f71808e: maintain watchdog timeout occurred flag To: barebox@lists.infradead.org Cc: Ahmad Fatoum If we experience a watchdog reset, the indicating flag should persist till the Linux driver had a chance to see it. The flag bit is special however in that writing 1 clears the bit and writing 0 keeps it intact, i.e. : Bit read written result 0 0 = 0 1 0 = 1 0 1 = 0 1 1 = 0 So in the bootloader, we should write a zero always. The OS on the other hand can either write 1 or the old value after reading to clear the flag. Signed-off-by: Ahmad Fatoum --- drivers/watchdog/f71808e_wdt.c | 59 +++++++++++++++++++++++----------- 1 file changed, 40 insertions(+), 19 deletions(-) diff --git a/drivers/watchdog/f71808e_wdt.c b/drivers/watchdog/f71808e_wdt.c index 6f2d30ec77aa..925c2f809df7 100644 --- a/drivers/watchdog/f71808e_wdt.c +++ b/drivers/watchdog/f71808e_wdt.c @@ -11,7 +11,6 @@ #include #include -#include #include #include #include @@ -114,30 +113,50 @@ static inline void superio_exit(u16 base) outb(SIO_LOCK_KEY, base); } +static inline u8 f71808e_wdt_conf_in(struct f71808e_wdt *wd) +{ + return superio_inb(wd->sioaddr, F71808FG_REG_WDT_CONF); +} + +static inline void f71808e_wdt_conf_out(struct f71808e_wdt *wd, u8 wdt_conf) +{ + /* + * Writing 1 to WDTMOUT_STS clears it. Writing 0 keeps the old state. + * We want the latter, so the OS driver can check it later on. + */ + wdt_conf &= ~BIT(F71808FG_FLAG_WDTMOUT_STS); + superio_outb(wd->sioaddr, F71808FG_REG_WDT_CONF, wdt_conf); +} + static void f71808e_wdt_keepalive(struct f71808e_wdt *wd) { + u8 wdt_conf; + superio_enter(wd->sioaddr); superio_select(wd->sioaddr, SIO_F71808FG_LD_WDT); + wdt_conf = f71808e_wdt_conf_in(wd); + if (wd->minutes_mode) /* select minutes for timer units */ - superio_set_bit(wd->sioaddr, F71808FG_REG_WDT_CONF, - F71808FG_FLAG_WD_UNIT); + wdt_conf |= BIT(F71808FG_FLAG_WD_UNIT); else /* select seconds for timer units */ - superio_clear_bit(wd->sioaddr, F71808FG_REG_WDT_CONF, - F71808FG_FLAG_WD_UNIT); + wdt_conf &= ~BIT(F71808FG_FLAG_WD_UNIT); + + f71808e_wdt_conf_out(wd, wdt_conf); /* Set timer value */ - superio_outb(wd->sioaddr, F71808FG_REG_WD_TIME, - wd->timer_val); + superio_outb(wd->sioaddr, F71808FG_REG_WD_TIME, wd->timer_val); superio_exit(wd->sioaddr); } static void f71808e_wdt_start(struct f71808e_wdt *wd) { + u8 wdt_conf; + /* Make sure we don't die as soon as the watchdog is enabled below */ f71808e_wdt_keepalive(wd); @@ -158,36 +177,38 @@ static void f71808e_wdt_start(struct f71808e_wdt *wd) superio_set_bit(wd->sioaddr, F71808FG_REG_WDO_CONF, F71808FG_FLAG_WDOUT_EN); - superio_set_bit(wd->sioaddr, F71808FG_REG_WDT_CONF, - F71808FG_FLAG_WD_EN); + wdt_conf = f71808e_wdt_conf_in(wd); + wdt_conf |= BIT(F71808FG_FLAG_WD_EN); + f71808e_wdt_conf_out(wd, wdt_conf); if (wd->pulse_width > 0) { /* Select "pulse" output mode with given duration */ - u8 wdt_conf = superio_inb(wd->sioaddr, F71808FG_REG_WDT_CONF); - /* Set WD_PSWIDTH bits (1:0) */ wdt_conf = (wdt_conf & 0xfc) | (wd->pulse_width & 0x03); /* Set WD_PULSE to "pulse" mode */ wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE); - superio_outb(wd->sioaddr, F71808FG_REG_WDT_CONF, wdt_conf); } else { /* Select "level" output mode */ - superio_clear_bit(wd->sioaddr, F71808FG_REG_WDT_CONF, - F71808FG_FLAG_WD_PULSE); + wdt_conf &= ~BIT(F71808FG_FLAG_WD_PULSE); } + f71808e_wdt_conf_out(wd, wdt_conf); + superio_exit(wd->sioaddr); } static void f71808e_wdt_stop(struct f71808e_wdt *wd) { + u8 wdt_conf; + superio_enter(wd->sioaddr); superio_select(wd->sioaddr, SIO_F71808FG_LD_WDT); - superio_clear_bit(wd->sioaddr, F71808FG_REG_WDT_CONF, - F71808FG_FLAG_WD_EN); + wdt_conf = f71808e_wdt_conf_in(wd); + wdt_conf &= ~BIT(F71808FG_FLAG_WD_EN); + f71808e_wdt_conf_out(wd, wdt_conf); superio_exit(wd->sioaddr); } @@ -222,14 +243,14 @@ static int f71808e_wdt_init(struct f71808e_wdt *wd, struct device_d *dev) { struct watchdog *wdd = &wd->wdd; const char * const *names = pulse_width_names; - unsigned long wdt_conf; + u8 wdt_conf; int ret; superio_enter(wd->sioaddr); superio_select(wd->sioaddr, SIO_F71808FG_LD_WDT); - wdt_conf = superio_inb(wd->sioaddr, F71808FG_REG_WDT_CONF); + wdt_conf = f71808e_wdt_conf_in(wd); superio_exit(wd->sioaddr); @@ -262,7 +283,7 @@ static int f71808e_wdt_init(struct f71808e_wdt *wd, struct device_d *dev) } - if (test_bit(F71808FG_FLAG_WD_EN, &wdt_conf)) + if (wdt_conf & BIT(F71808FG_FLAG_WD_EN)) wdd->running = WDOG_HW_RUNNING; else wdd->running = WDOG_HW_NOT_RUNNING; -- 2.27.0 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox