[PATCH v4] ARM: zynq: use restart_handler mechanism for slcr reset

From: Josh Cartwright
Date: Thu Mar 19 2015 - 10:25:10 EST


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@xxxxxx>
---

v3 -> v4: Document restart notifier callback parameters.
v2 -> v3: Don't drop the kerneldoc
v1 -> v2: Also drop zynq_slcr_system_reset prototype from common.h

arch/arm/mach-zynq/common.c | 6 ------
arch/arm/mach-zynq/common.h | 1 -
arch/arm/mach-zynq/slcr.c | 21 +++++++++++++++++++--
3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/arch/arm/mach-zynq/common.c b/arch/arm/mach-zynq/common.c
index 58ef2a7..616d584 100644
--- a/arch/arm/mach-zynq/common.c
+++ b/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
diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h
index 382c60e..f2f0bf2 100644
--- a/arch/arm/mach-zynq/common.h
+++ b/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);
diff --git a/arch/arm/mach-zynq/slcr.c b/arch/arm/mach-zynq/slcr.c
index c3c24fd8..af8fb50 100644
--- a/arch/arm/mach-zynq/slcr.c
+++ b/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: a negative value on error, 0 on success
*/
-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);
--
2.3.3

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