power/reset: xgene: Register with kernel restart handler

Register with kernel restart handler instead of setting arm_pm_restart directly.

This patch also addresses the following compile warning.

drivers/power/reset/xgene-reboot.c: In function 'xgene_reboot_probe':
drivers/power/reset/xgene-reboot.c:77:17: warning:
	assignment from incompatible pointer type [enabled by default]

The warning was due to a mismatch between the type of arm_pm_restart
and the restart function.

Cc: Loc Ho <lho@apm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/power/reset/xgene-reboot.c

@@ -26,38 +26,43 @@
  */
 #include <linux/delay.h>
 #include <linux/io.h>
+#include <linux/notifier.h>
 #include <linux/of_device.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
+#include <linux/reboot.h>
 #include <linux/stat.h>
 #include <linux/slab.h>
-#include <asm/system_misc.h>
 
 struct xgene_reboot_context {
 	struct device *dev;
 	void *csr;
 	u32 mask;
+	struct notifier_block restart_handler;
 };
 
-static struct xgene_reboot_context *xgene_restart_ctx;
-
-static void xgene_restart(enum reboot_mode mode, const char *cmd)
+static int xgene_restart_handler(struct notifier_block *this,
+				 unsigned long mode, void *cmd)
 {
-	struct xgene_reboot_context *ctx = xgene_restart_ctx;
+	struct xgene_reboot_context *ctx =
+		container_of(this, struct xgene_reboot_context,
+			     restart_handler);
 
 	/* Issue the reboot */
-	if (ctx)
 	writel(ctx->mask, ctx->csr);
 
 	mdelay(1000);
 
 	dev_emerg(ctx->dev, "Unable to restart system\n");
+
+	return NOTIFY_DONE;
 }
 
 static int xgene_reboot_probe(struct platform_device *pdev)
 {
 	struct xgene_reboot_context *ctx;
 	struct device *dev = &pdev->dev;
+	int err;
 
 	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
@@ -73,10 +78,13 @@ static int xgene_reboot_probe(struct platform_device *pdev)
 		ctx->mask = 0xFFFFFFFF;
 
 	ctx->dev = dev;
-	arm_pm_restart = xgene_restart;
-	xgene_restart_ctx = ctx;
+	ctx->restart_handler.notifier_call = xgene_restart_handler;
+	ctx->restart_handler.priority = 128;
+	err = register_restart_handler(&ctx->restart_handler);
+	if (err)
+		dev_err(dev, "cannot register restart handler (err=%d)\n", err);
 
-	return 0;
+	return err;
 }
 
 static struct of_device_id xgene_reboot_of_match[] = {