[PATCH V2 2/3] watchdog: stm32: update return values recommended by watchdog kernel api

[Ludovic Barre]

From: Ludovic Barre <ludovic.ba...@st.com>

This patch updates return values on watchdog-kernel-api.txt:
return 0 on succes, -EINVAL for "parameter out of range"
and -EIO for "could not write value to the watchdog".

Signed-off-by: Ludovic Barre <ludovic.ba...@st.com>
---
 drivers/watchdog/stm32_iwdg.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c
index e191bd8..f19a6d4 100644
--- a/drivers/watchdog/stm32_iwdg.c
+++ b/drivers/watchdog/stm32_iwdg.c
@@ -81,7 +81,6 @@ static int stm32_iwdg_start(struct watchdog_device *wdd)
        struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd);
        u32 val = FLAG_PVU | FLAG_RVU;
        u32 reload;
-       int ret;
 
        dev_dbg(wdd->parent, "%s\n", __func__);
 
@@ -98,13 +97,11 @@ static int stm32_iwdg_start(struct watchdog_device *wdd)
        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, val,
-                                        !(val & (FLAG_PVU | FLAG_RVU)),
-                                        SLEEP_US, TIMEOUT_US);
-       if (ret) {
-               dev_err(wdd->parent,
-                       "Fail to set prescaler or reload registers\n");
-               return ret;
+       if (readl_relaxed_poll_timeout(wdt->regs + IWDG_SR, val,
+                                      !(val & (FLAG_PVU | FLAG_RVU)),
+                                      SLEEP_US, TIMEOUT_US)) {
+               dev_err(wdd->parent, "Fail to set prescaler, reload regs\n");
+               return -EIO;
        }
 
        /* reload watchdog */
@@ -128,8 +125,16 @@ static int stm32_iwdg_ping(struct watchdog_device *wdd)
 static int stm32_iwdg_set_timeout(struct watchdog_device *wdd,
                                  unsigned int timeout)
 {
+       unsigned int tout = clamp(timeout, wdd->min_timeout,
+                                 wdd->max_hw_heartbeat_ms / 1000);
+
        dev_dbg(wdd->parent, "%s timeout: %d sec\n", __func__, timeout);
 
+       if (tout != timeout) {
+               dev_err(wdd->parent, "parameter out of range\n");
+               return -EINVAL;
+       }
+
        wdd->timeout = timeout;
 
        if (watchdog_active(wdd))
-- 
2.7.4