From: Christophe Roullier <christophe.roullier@st.com>
To: <wim@linux-watchdog.org>, <linux@roeck-us.net>,
<mcoquelin.stm32@gmail.com>, <alexandre.torgue@st.com>
Cc: <linux-watchdog@vger.kernel.org>, <christophe.roullier@st.com>,
<linux-kernel@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>
Subject: [PATCH 1/1] drivers: watchdog: stm32_iwdg: set WDOG_HW_RUNNING at probe
Date: Thu, 21 Nov 2019 09:28:13 +0100 [thread overview]
Message-ID: <20191121082813.29267-2-christophe.roullier@st.com> (raw)
In-Reply-To: <20191121082813.29267-1-christophe.roullier@st.com>
If the watchdog hardware is already enabled during the boot process,
when the Linux watchdog driver loads, it should reset the watchdog and
tell the watchdog framework. As a result, ping can be generated from
the watchdog framework (if CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED is set),
until the userspace watchdog daemon takes over control
Fixes:4332d113c66a ("watchdog: Add STM32 IWDG driver")
Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
---
drivers/watchdog/stm32_iwdg.c | 57 ++++++++++++++++++++++++-----------
1 file changed, 40 insertions(+), 17 deletions(-)
diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c
index a3a329011a06..2b3be3b1c15b 100644
--- a/drivers/watchdog/stm32_iwdg.c
+++ b/drivers/watchdog/stm32_iwdg.c
@@ -87,8 +87,23 @@ static inline void reg_write(void __iomem *base, u32 reg, u32 val)
static int stm32_iwdg_start(struct watchdog_device *wdd)
{
struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd);
- u32 tout, presc, iwdg_rlr, iwdg_pr, iwdg_sr;
- int ret;
+
+ dev_dbg(wdd->parent, "%s\n", __func__);
+
+ /* Start the watchdog */
+ reg_write(wdt->regs, IWDG_KR, KR_KEY_ENABLE);
+
+ /* reload watchdog */
+ reg_write(wdt->regs, IWDG_KR, KR_KEY_RELOAD);
+
+ set_bit(WDOG_HW_RUNNING, &wdd->status);
+ return 0;
+}
+
+static int stm32_iwdg_setprescaler(struct watchdog_device *wdd)
+{
+ struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd);
+ u32 tout, presc, iwdg_rlr, iwdg_pr;
dev_dbg(wdd->parent, "%s\n", __func__);
@@ -108,19 +123,6 @@ static int stm32_iwdg_start(struct watchdog_device *wdd)
/* set prescaler & reload registers */
reg_write(wdt->regs, IWDG_PR, iwdg_pr);
reg_write(wdt->regs, IWDG_RLR, iwdg_rlr);
- reg_write(wdt->regs, IWDG_KR, KR_KEY_ENABLE);
-
- /* wait for the registers to be updated (max 100ms) */
- ret = readl_relaxed_poll_timeout(wdt->regs + IWDG_SR, iwdg_sr,
- !(iwdg_sr & (SR_PVU | SR_RVU)),
- SLEEP_US, TIMEOUT_US);
- if (ret) {
- dev_err(wdd->parent, "Fail to set prescaler, reload regs\n");
- return ret;
- }
-
- /* reload watchdog */
- reg_write(wdt->regs, IWDG_KR, KR_KEY_RELOAD);
return 0;
}
@@ -131,6 +133,9 @@ static int stm32_iwdg_ping(struct watchdog_device *wdd)
dev_dbg(wdd->parent, "%s\n", __func__);
+ /* Start the watchdog */
+ reg_write(wdt->regs, IWDG_KR, KR_KEY_ENABLE);
+
/* reload watchdog */
reg_write(wdt->regs, IWDG_KR, KR_KEY_RELOAD);
@@ -140,12 +145,21 @@ static int stm32_iwdg_ping(struct watchdog_device *wdd)
static int stm32_iwdg_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
+ int ret;
+
dev_dbg(wdd->parent, "%s timeout: %d sec\n", __func__, timeout);
wdd->timeout = timeout;
- if (watchdog_active(wdd))
- return stm32_iwdg_start(wdd);
+ if (watchdog_active(wdd)) {
+ ret = stm32_iwdg_setprescaler(wdd);
+ if (ret) {
+ dev_err(wdd->parent, "failed to set prescaler\n");
+ return ret;
+ } else {
+ return stm32_iwdg_start(wdd);
+ }
+ }
return 0;
}
@@ -262,12 +276,21 @@ static int stm32_iwdg_probe(struct platform_device *pdev)
watchdog_set_nowayout(wdd, WATCHDOG_NOWAYOUT);
watchdog_init_timeout(wdd, 0, dev);
+ /* Make sure the watchdog is serviced */
+ set_bit(WDOG_HW_RUNNING, &wdd->status);
+
ret = devm_watchdog_register_device(dev, wdd);
if (ret)
return ret;
platform_set_drvdata(pdev, wdt);
+ ret = stm32_iwdg_setprescaler(wdd);
+ if (ret) {
+ dev_err(dev, "failed to set prescaler\n");
+ return ret;
+ }
+
return 0;
}
--
2.17.1
next prev parent reply other threads:[~2019-11-21 8:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-21 8:28 [PATCH 0/1] stm32_iwdg: set WDOG_HW_RUNNING at probe Christophe Roullier
2019-11-21 8:28 ` Christophe Roullier [this message]
2019-11-21 9:53 ` [PATCH 1/1] drivers: watchdog: " Guenter Roeck
2019-11-21 13:45 ` Christophe ROULLIER
2019-11-21 14:21 ` Guenter Roeck
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