clk: samsung: register restart handlers for s3c2412 and s3c2443
S3C2412, S3C2443 and their derivatives contain a special software-reset
register in their system-controller.
Therefore register a restart handler for those.
Tested on a s3c2416-based board, s3c2412 compile-tested.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/drivers/clk/samsung/clk-s3c2412.c b/drivers/clk/samsung/clk-s3c2412.c
index 34af09f..2ceedaf 100644
--- a/drivers/clk/samsung/clk-s3c2412.c
+++ b/drivers/clk/samsung/clk-s3c2412.c
@@ -14,6 +14,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/syscore_ops.h>
+#include <linux/reboot.h>
#include <dt-bindings/clock/s3c2412.h>
@@ -26,6 +27,7 @@
#define CLKCON 0x0c
#define CLKDIVN 0x14
#define CLKSRC 0x1c
+#define SWRST 0x30
/* list of PLLs to be registered */
enum s3c2412_plls {
@@ -204,6 +206,28 @@
ALIAS(MSYSCLK, NULL, "fclk"),
};
+static int s3c2412_restart(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ /* errata "Watch-dog/Software Reset Problem" specifies that
+ * this reset must be done with the SYSCLK sourced from
+ * EXTCLK instead of FOUT to avoid a glitch in the reset
+ * mechanism.
+ *
+ * See the watchdog section of the S3C2412 manual for more
+ * information on this fix.
+ */
+
+ __raw_writel(0x00, reg_base + CLKSRC);
+ __raw_writel(0x533C2412, reg_base + SWRST);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block s3c2412_restart_handler = {
+ .notifier_call = s3c2412_restart,
+ .priority = 129,
+};
+
/*
* fixed rate clocks generated outside the soc
* Only necessary until the devicetree-move is complete
@@ -233,6 +257,7 @@
unsigned long ext_f, void __iomem *base)
{
struct samsung_clk_provider *ctx;
+ int ret;
reg_base = base;
if (np) {
@@ -267,6 +292,10 @@
s3c2412_clk_sleep_init();
samsung_clk_of_add_provider(np, ctx);
+
+ ret = register_restart_handler(&s3c2412_restart_handler);
+ if (ret)
+ pr_warn("cannot register restart handler, %d\n", ret);
}
static void __init s3c2412_clk_init(struct device_node *np)