[PATCH 1/2] watchdog: imxwd: register explicit warm reset handler

[Ahmad Fatoum]

With fsl,ext-reset-output and WDOG_B muxed correctly, the i.MX watchdog
will toggle an external signal to effect a PMIC reset.

That's good for normal use, but when exchanging information with the
BootROM over GPRs, a warm reset is required. This is needed e.g. to
set the reboot mode. Support this by defining a second, lower
priority, reset that will never toggle external lines.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 drivers/watchdog/imxwd.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/watchdog/imxwd.c b/drivers/watchdog/imxwd.c
index 26c62b7bcb31..a109f6fee712 100644
--- a/drivers/watchdog/imxwd.c
+++ b/drivers/watchdog/imxwd.c
@@ -39,6 +39,7 @@ struct imx_wd {
 	struct device_d *dev;
 	const struct imx_wd_ops *ops;
 	struct restart_handler restart;
+	struct restart_handler restart_warm;
 	bool ext_reset;
 	bool bigendian;
 };
@@ -183,6 +184,14 @@ static void __noreturn imxwd_force_soc_reset(struct restart_handler *rst)
 	hang();
 }
 
+static void __noreturn imxwd_force_soc_reset_internal(struct restart_handler *rst)
+{
+	struct imx_wd *priv = container_of(rst, struct imx_wd, restart_warm);
+
+	priv->ext_reset = false;
+	imxwd_force_soc_reset(&priv->restart);
+}
+
 static void imx_watchdog_detect_reset_source(struct imx_wd *priv)
 {
 	u16 val = imxwd_read(priv, IMX21_WDOG_WSTR);
@@ -284,9 +293,16 @@ static int imx_wd_probe(struct device_d *dev)
 
 	priv->restart.name = "imxwd";
 	priv->restart.restart = imxwd_force_soc_reset;
+	priv->restart.priority = RESTART_DEFAULT_PRIORITY;
 
 	restart_handler_register(&priv->restart);
 
+	priv->restart_warm.name = "imxwd-warm";
+	priv->restart_warm.restart = imxwd_force_soc_reset_internal;
+	priv->restart_warm.priority = RESTART_DEFAULT_PRIORITY - 10;
+
+	restart_handler_register(&priv->restart_warm);
+
 	return 0;
 
 error_unregister:
-- 
2.30.2