[PATCH v6 4/6] watchdog: pnx4008: restart: support "cmd" from userspace

[Sylvain Lemieux]

From: Sylvain Lemieux <slemieux at tycoint.com>

Added support to verify if a "cmd" is passed from the userspace program rebooting the system;
- if a valid "cmd" is available, handle it;
- If the received "cmd" is not supported, use the default reboot mode.

Signed-off-by: Sylvain Lemieux <slemieux at tycoint.com>
---
Changes from v5 to v6:
- remove typecast.

Changes from v4 to v5:
- no logical change; updated to work with new revision of patch #2.

Changes from v3 to v4:
- none.

Changes from v2 to v3:
- no logical change; updated to work with new revision of patch #2.

Changes from v1 to v2:
- Rename patch title;
  was "arm: lpc32xx: restart: support "cmd" from userspace"
- Add change to "pnx-4008" driver instead of "mach-lpc32xx".

 drivers/watchdog/pnx4008_wdt.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/watchdog/pnx4008_wdt.c b/drivers/watchdog/pnx4008_wdt.c
index 51be66e..4162135 100644
--- a/drivers/watchdog/pnx4008_wdt.c
+++ b/drivers/watchdog/pnx4008_wdt.c
@@ -129,6 +129,21 @@ static int pnx4008_wdt_set_timeout(struct watchdog_device *wdd,
 static int pnx4008_restart_handler(struct watchdog_device *wdd,
 				   unsigned long mode, void *cmd)
 {
+	const char *boot_cmd = (const char *)cmd;
+
+	/*
+	 * Verify if a "cmd" passed from the userspace program rebooting
+	 * the system; if available, handle it.
+	 * - For details, see the 'reboot' syscall in kernel/reboot.c
+	 * - If the received "cmd" is not supported, use the default mode.
+	 */
+	if (boot_cmd) {
+		if (boot_cmd[0] == 'h')
+			mode = REBOOT_HARD;
+		else if (boot_cmd[0] == 's')
+			mode = REBOOT_SOFT;
+	}
+
 	if (mode == REBOOT_SOFT) {
 		/* Force match output active */
 		writel(EXT_MATCH0, WDTIM_EMR(wdt_base));
-- 
1.8.3.1