ARM: zynq: Use restart_handler mechanism for slcr reset

By making use of the restart_handler chain mechanism, the SLCR-based
reset mechanism can be prioritized amongst other mechanisms available on
a particular board.

Choose a default high-ish priority of 192 for this restart mechanism.
Signed-off-by: Josh Cartwright <joshc@ni.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/mach-zynq/common.c

@@ -190,11 +190,6 @@ static void __init zynq_irq_init(void)
 	irqchip_init();
 }
 
-static void zynq_system_reset(enum reboot_mode mode, const char *cmd)
-{
-	zynq_slcr_system_reset();
-}
-
 static const char * const zynq_dt_match[] = {
 	"xlnx,zynq-7000",
 	NULL
@@ -212,5 +207,4 @@ DT_MACHINE_START(XILINX_EP107, "Xilinx Zynq Platform")
 	.init_time	= zynq_timer_init,
 	.dt_compat	= zynq_dt_match,
 	.reserve	= zynq_memory_init,
-	.restart	= zynq_system_reset,
 MACHINE_END

arch/arm/mach-zynq/common.h

@@ -21,7 +21,6 @@ void zynq_secondary_startup(void);
 
 extern int zynq_slcr_init(void);
 extern int zynq_early_slcr_init(void);
-extern void zynq_slcr_system_reset(void);
 extern void zynq_slcr_cpu_stop(int cpu);
 extern void zynq_slcr_cpu_start(int cpu);
 extern bool zynq_slcr_cpu_state_read(int cpu);

arch/arm/mach-zynq/slcr.c

@@ -15,6 +15,7 @@
  */
 
 #include <linux/io.h>
+#include <linux/reboot.h>
 #include <linux/mfd/syscon.h>
 #include <linux/of_address.h>
 #include <linux/regmap.h>
@@ -92,9 +93,17 @@ u32 zynq_slcr_get_device_id(void)
 }
 
 /**
- * zynq_slcr_system_reset - Reset the entire system.
+ * zynq_slcr_system_restart - Restart the entire system.
+ *
+ * @nb:		Pointer to restart notifier block (unused)
+ * @action:	Reboot mode (unused)
+ * @data:	Restart handler private data (unused)
+ *
+ * Return:	0 always
  */
-void zynq_slcr_system_reset(void)
+static
+int zynq_slcr_system_restart(struct notifier_block *nb,
+			     unsigned long action, void *data)
 {
 	u32 reboot;
 
@@ -113,8 +122,14 @@ void zynq_slcr_system_reset(void)
 	zynq_slcr_read(&reboot, SLCR_REBOOT_STATUS_OFFSET);
 	zynq_slcr_write(reboot & 0xF0FFFFFF, SLCR_REBOOT_STATUS_OFFSET);
 	zynq_slcr_write(1, SLCR_PS_RST_CTRL_OFFSET);
+	return 0;
 }
 
+static struct notifier_block zynq_slcr_restart_nb = {
+	.notifier_call	= zynq_slcr_system_restart,
+	.priority	= 192,
+};
+
 /**
  * zynq_slcr_cpu_start - Start cpu
  * @cpu:	cpu number
@@ -219,6 +234,8 @@ int __init zynq_early_slcr_init(void)
 	/* unlock the SLCR so that registers can be changed */
 	zynq_slcr_unlock();
 
+	register_restart_handler(&zynq_slcr_restart_nb);
+
 	pr_info("%s mapped to %p\n", np->name, zynq_slcr_base);
 
 	of_node_put(np);