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authorPhilippe Boos <pboos@baylibre.com>2022-08-01 11:21:50 +0200
committerWim Van Sebroeck <wim@linux-watchdog.org>2022-10-02 12:55:41 +0200
commit6adbfbab0f039bb89edb9d3ad0d9ac8a18efa6db (patch)
tree1a130697eaeda47e8d87acc61bf7122ec9ccdabc /drivers/watchdog
parentb24620608dc2b54cb9df511e3d2c789f99497538 (diff)
downloadlinux-6adbfbab0f039bb89edb9d3ad0d9ac8a18efa6db.tar.bz2
watchdog: meson: keep running if already active
If the watchdog is already running (e.g.: started by bootloader) then the kernel driver should keep the watchdog active but the amlogic driver turns it off. Let the driver fix the clock rate if already active because we do not know the previous timebase value. To avoid unintentional resetting we temporarily set it to its maximum value. Then keep the enable bit if is was previously active. Signed-off-by: Philippe Boos <pboos@baylibre.com> Reviewed-by: Jerome Brunet <jbrunet@baylibre.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20220801092150.4449-1-pboos@baylibre.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Diffstat (limited to 'drivers/watchdog')
-rw-r--r--drivers/watchdog/meson_gxbb_wdt.c24
1 files changed, 19 insertions, 5 deletions
diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index d3c9e2f6e63b..981a2f7c3bec 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -156,6 +156,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct meson_gxbb_wdt *data;
int ret;
+ u32 ctrl_reg;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
@@ -189,13 +190,26 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
watchdog_set_nowayout(&data->wdt_dev, nowayout);
watchdog_set_drvdata(&data->wdt_dev, data);
+ ctrl_reg = readl(data->reg_base + GXBB_WDT_CTRL_REG) &
+ GXBB_WDT_CTRL_EN;
+
+ if (ctrl_reg) {
+ /* Watchdog is running - keep it running but extend timeout
+ * to the maximum while setting the timebase
+ */
+ set_bit(WDOG_HW_RUNNING, &data->wdt_dev.status);
+ meson_gxbb_wdt_set_timeout(&data->wdt_dev,
+ GXBB_WDT_TCNT_SETUP_MASK / 1000);
+ }
+
/* Setup with 1ms timebase */
- writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) |
- GXBB_WDT_CTRL_EE_RESET |
- GXBB_WDT_CTRL_CLK_EN |
- GXBB_WDT_CTRL_CLKDIV_EN,
- data->reg_base + GXBB_WDT_CTRL_REG);
+ ctrl_reg |= ((clk_get_rate(data->clk) / 1000) &
+ GXBB_WDT_CTRL_DIV_MASK) |
+ GXBB_WDT_CTRL_EE_RESET |
+ GXBB_WDT_CTRL_CLK_EN |
+ GXBB_WDT_CTRL_CLKDIV_EN;
+ writel(ctrl_reg, data->reg_base + GXBB_WDT_CTRL_REG);
meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
return devm_watchdog_register_device(dev, &data->wdt_dev);