From e317c19470f6d690122519bf9ed1c9f21ea11906 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Heiko=20St=C3=BCbner?= Date: Tue, 19 Aug 2014 17:45:37 -0700 Subject: [PATCH] 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 Signed-off-by: Guenter Roeck --- drivers/clk/samsung/clk-s3c2412.c | 29 +++++++++++++++++++++++++++++ drivers/clk/samsung/clk-s3c2443.c | 19 +++++++++++++++++++ 2 files changed, 48 insertions(+) diff --git a/drivers/clk/samsung/clk-s3c2412.c b/drivers/clk/samsung/clk-s3c2412.c index 34af09f6a155..2ceedaf8ce18 100644 --- a/drivers/clk/samsung/clk-s3c2412.c +++ b/drivers/clk/samsung/clk-s3c2412.c @@ -14,6 +14,7 @@ #include #include #include +#include #include @@ -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 @@ struct samsung_clock_alias s3c2412_aliases[] __initdata = { 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 @@ void __init s3c2412_common_clk_init(struct device_node *np, unsigned long xti_f, unsigned long ext_f, void __iomem *base) { struct samsung_clk_provider *ctx; + int ret; reg_base = base; if (np) { @@ -267,6 +292,10 @@ void __init s3c2412_common_clk_init(struct device_node *np, unsigned long xti_f, 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) diff --git a/drivers/clk/samsung/clk-s3c2443.c b/drivers/clk/samsung/clk-s3c2443.c index c92f853fca9f..0c3c182b902a 100644 --- a/drivers/clk/samsung/clk-s3c2443.c +++ b/drivers/clk/samsung/clk-s3c2443.c @@ -14,6 +14,7 @@ #include #include #include +#include #include @@ -33,6 +34,7 @@ #define HCLKCON 0x30 #define PCLKCON 0x34 #define SCLKCON 0x38 +#define SWRST 0x44 /* the soc types */ enum supported_socs { @@ -354,6 +356,18 @@ struct samsung_clock_alias s3c2450_aliases[] __initdata = { ALIAS(PCLK_I2C1, "s3c2410-i2c.1", "i2c"), }; +static int s3c2443_restart(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + __raw_writel(0x533c2443, reg_base + SWRST); + return NOTIFY_DONE; +} + +static struct notifier_block s3c2443_restart_handler = { + .notifier_call = s3c2443_restart, + .priority = 129, +}; + /* * fixed rate clocks generated outside the soc * Only necessary until the devicetree-move is complete @@ -378,6 +392,7 @@ void __init s3c2443_common_clk_init(struct device_node *np, unsigned long xti_f, void __iomem *base) { struct samsung_clk_provider *ctx; + int ret; reg_base = base; if (np) { @@ -447,6 +462,10 @@ void __init s3c2443_common_clk_init(struct device_node *np, unsigned long xti_f, s3c2443_clk_sleep_init(); samsung_clk_of_add_provider(np, ctx); + + ret = register_restart_handler(&s3c2443_restart_handler); + if (ret) + pr_warn("cannot register restart handler, %d\n", ret); } static void __init s3c2416_clk_init(struct device_node *np) -- 2.20.1