ARM: imx: move clk_prepare() out from mxc_restart()

It's inappropriate to call clk_prepare() in mxc_restart(), because the
restart routine could be called in atomic context.  Move clk_get() and
clk_prepare() into mxc_arch_reset_init() and only have the atomic part
clk_enable() be called in mxc_restart().

As a result, mxc_arch_reset_init() needs to be called after clk gets
initialized.

While there, it also changes printk(KERN_ERR ...) to pr_err() and adds
__init annotation for mxc_arch_reset_init().
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/mach-imx/imx25-dt.c

@@ -15,10 +15,13 @@
 #include <asm/mach/arch.h>
 #include <asm/mach/time.h>
 #include "common.h"
+#include "hardware.h"
 #include "mx25.h"
 
 static void __init imx25_dt_init(void)
 {
+	mxc_arch_reset_init(MX25_IO_ADDRESS(MX25_WDOG_BASE_ADDR));
+
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 }
 

arch/arm/mach-imx/imx27-dt.c

@@ -16,12 +16,15 @@
 #include <asm/mach/time.h>
 
 #include "common.h"
+#include "hardware.h"
 #include "mx27.h"
 
 static void __init imx27_dt_init(void)
 {
 	struct platform_device_info devinfo = { .name = "cpufreq-cpu0", };
 
+	mxc_arch_reset_init(MX27_IO_ADDRESS(MX27_WDOG_BASE_ADDR));
+
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 
 	platform_device_register_full(&devinfo);

arch/arm/mach-imx/imx31-dt.c

@@ -16,10 +16,13 @@
 #include <asm/mach/time.h>
 
 #include "common.h"
+#include "hardware.h"
 #include "mx31.h"
 
 static void __init imx31_dt_init(void)
 {
+	mxc_arch_reset_init(MX31_IO_ADDRESS(MX31_WDOG_BASE_ADDR));
+
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 }
 

arch/arm/mach-imx/imx51-dt.c

@@ -17,12 +17,15 @@
 #include <asm/mach/time.h>
 
 #include "common.h"
+#include "hardware.h"
 #include "mx51.h"
 
 static void __init imx51_dt_init(void)
 {
 	struct platform_device_info devinfo = { .name = "cpufreq-cpu0", };
 
+	mxc_arch_reset_init(MX51_IO_ADDRESS(MX51_WDOG1_BASE_ADDR));
+
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 	platform_device_register_full(&devinfo);
 }

arch/arm/mach-imx/mach-imx53.c

@@ -21,6 +21,7 @@
 #include <asm/mach/time.h>
 
 #include "common.h"
+#include "hardware.h"
 #include "mx53.h"
 
 static void __init imx53_qsb_init(void)
@@ -38,6 +39,8 @@ static void __init imx53_qsb_init(void)
 
 static void __init imx53_dt_init(void)
 {
+	mxc_arch_reset_init(MX53_IO_ADDRESS(MX53_WDOG1_BASE_ADDR));
+
 	if (of_machine_is_compatible("fsl,imx53-qsb"))
 		imx53_qsb_init();
 

arch/arm/mach-imx/mm-imx1.c

@@ -39,7 +39,6 @@ void __init mx1_map_io(void)
 void __init imx1_init_early(void)
 {
 	mxc_set_cpu_type(MXC_CPU_MX1);
-	mxc_arch_reset_init(MX1_IO_ADDRESS(MX1_WDT_BASE_ADDR));
 	imx_iomuxv1_init(MX1_IO_ADDRESS(MX1_GPIO_BASE_ADDR),
 			MX1_NUM_GPIO_PORT);
 }
@@ -51,6 +50,7 @@ void __init mx1_init_irq(void)
 
 void __init imx1_soc_init(void)
 {
+	mxc_arch_reset_init(MX1_IO_ADDRESS(MX1_WDT_BASE_ADDR));
 	mxc_device_init();
 
 	mxc_register_gpio("imx1-gpio", 0, MX1_GPIO1_BASE_ADDR, SZ_256,

arch/arm/mach-imx/mm-imx21.c

@@ -66,7 +66,6 @@ void __init mx21_map_io(void)
 void __init imx21_init_early(void)
 {
 	mxc_set_cpu_type(MXC_CPU_MX21);
-	mxc_arch_reset_init(MX21_IO_ADDRESS(MX21_WDOG_BASE_ADDR));
 	imx_iomuxv1_init(MX21_IO_ADDRESS(MX21_GPIO_BASE_ADDR),
 			MX21_NUM_GPIO_PORT);
 }
@@ -82,6 +81,7 @@ static const struct resource imx21_audmux_res[] __initconst = {
 
 void __init imx21_soc_init(void)
 {
+	mxc_arch_reset_init(MX21_IO_ADDRESS(MX21_WDOG_BASE_ADDR));
 	mxc_device_init();
 
 	mxc_register_gpio("imx21-gpio", 0, MX21_GPIO1_BASE_ADDR, SZ_256, MX21_INT_GPIO, 0);

arch/arm/mach-imx/mm-imx25.c

@@ -54,7 +54,6 @@ void __init imx25_init_early(void)
 {
 	mxc_set_cpu_type(MXC_CPU_MX25);
 	mxc_iomux_v3_init(MX25_IO_ADDRESS(MX25_IOMUXC_BASE_ADDR));
-	mxc_arch_reset_init(MX25_IO_ADDRESS(MX25_WDOG_BASE_ADDR));
 }
 
 void __init mx25_init_irq(void)
@@ -89,6 +88,7 @@ static const struct resource imx25_audmux_res[] __initconst = {
 
 void __init imx25_soc_init(void)
 {
+	mxc_arch_reset_init(MX25_IO_ADDRESS(MX25_WDOG_BASE_ADDR));
 	mxc_device_init();
 
 	/* i.mx25 has the i.mx35 type gpio */

arch/arm/mach-imx/mm-imx27.c

@@ -66,7 +66,6 @@ void __init mx27_map_io(void)
 void __init imx27_init_early(void)
 {
 	mxc_set_cpu_type(MXC_CPU_MX27);
-	mxc_arch_reset_init(MX27_IO_ADDRESS(MX27_WDOG_BASE_ADDR));
 	imx_iomuxv1_init(MX27_IO_ADDRESS(MX27_GPIO_BASE_ADDR),
 			MX27_NUM_GPIO_PORT);
 }
@@ -82,6 +81,7 @@ static const struct resource imx27_audmux_res[] __initconst = {
 
 void __init imx27_soc_init(void)
 {
+	mxc_arch_reset_init(MX27_IO_ADDRESS(MX27_WDOG_BASE_ADDR));
 	mxc_device_init();
 
 	/* i.mx27 has the i.mx21 type gpio */

arch/arm/mach-imx/mm-imx3.c

@@ -138,7 +138,6 @@ void __init mx31_map_io(void)
 void __init imx31_init_early(void)
 {
 	mxc_set_cpu_type(MXC_CPU_MX31);
-	mxc_arch_reset_init(MX31_IO_ADDRESS(MX31_WDOG_BASE_ADDR));
 	arch_ioremap_caller = imx3_ioremap_caller;
 	arm_pm_idle = imx3_idle;
 	mx3_ccm_base = MX31_IO_ADDRESS(MX31_CCM_BASE_ADDR);
@@ -174,6 +173,7 @@ void __init imx31_soc_init(void)
 
 	imx3_init_l2x0();
 
+	mxc_arch_reset_init(MX31_IO_ADDRESS(MX31_WDOG_BASE_ADDR));
 	mxc_device_init();
 
 	mxc_register_gpio("imx31-gpio", 0, MX31_GPIO1_BASE_ADDR, SZ_16K, MX31_INT_GPIO1, 0);
@@ -216,7 +216,6 @@ void __init imx35_init_early(void)
 {
 	mxc_set_cpu_type(MXC_CPU_MX35);
 	mxc_iomux_v3_init(MX35_IO_ADDRESS(MX35_IOMUXC_BASE_ADDR));
-	mxc_arch_reset_init(MX35_IO_ADDRESS(MX35_WDOG_BASE_ADDR));
 	arm_pm_idle = imx3_idle;
 	arch_ioremap_caller = imx3_ioremap_caller;
 	mx3_ccm_base = MX35_IO_ADDRESS(MX35_CCM_BASE_ADDR);
@@ -272,6 +271,7 @@ void __init imx35_soc_init(void)
 
 	imx3_init_l2x0();
 
+	mxc_arch_reset_init(MX35_IO_ADDRESS(MX35_WDOG_BASE_ADDR));
 	mxc_device_init();
 
 	mxc_register_gpio("imx35-gpio", 0, MX35_GPIO1_BASE_ADDR, SZ_16K, MX35_INT_GPIO1, 0);

arch/arm/mach-imx/mm-imx5.c

@@ -83,7 +83,6 @@ void __init imx51_init_early(void)
 	imx51_ipu_mipi_setup();
 	mxc_set_cpu_type(MXC_CPU_MX51);
 	mxc_iomux_v3_init(MX51_IO_ADDRESS(MX51_IOMUXC_BASE_ADDR));
-	mxc_arch_reset_init(MX51_IO_ADDRESS(MX51_WDOG1_BASE_ADDR));
 	imx_src_init();
 }
 
@@ -91,7 +90,6 @@ void __init imx53_init_early(void)
 {
 	mxc_set_cpu_type(MXC_CPU_MX53);
 	mxc_iomux_v3_init(MX53_IO_ADDRESS(MX53_IOMUXC_BASE_ADDR));
-	mxc_arch_reset_init(MX53_IO_ADDRESS(MX53_WDOG1_BASE_ADDR));
 	imx_src_init();
 }
 
@@ -129,6 +127,7 @@ static const struct resource imx51_audmux_res[] __initconst = {
 
 void __init imx51_soc_init(void)
 {
+	mxc_arch_reset_init(MX51_IO_ADDRESS(MX51_WDOG1_BASE_ADDR));
 	mxc_device_init();
 
 	/* i.mx51 has the i.mx35 type gpio */

arch/arm/mach-imx/system.c

@@ -30,6 +30,7 @@
 #include "hardware.h"
 
 static void __iomem *wdog_base;
+static struct clk *wdog_clk;
 
 /*
  * Reset the system. It is called by machine_restart().
@@ -38,16 +39,13 @@ void mxc_restart(char mode, const char *cmd)
 {
 	unsigned int wcr_enable;
 
-	if (cpu_is_mx1()) {
-		wcr_enable = (1 << 0);
-	} else {
-		struct clk *clk;
+	if (wdog_clk)
+		clk_enable(wdog_clk);
 
-		clk = clk_get_sys("imx2-wdt.0", NULL);
-		if (!IS_ERR(clk))
-			clk_prepare_enable(clk);
+	if (cpu_is_mx1())
+		wcr_enable = (1 << 0);
+	else
 		wcr_enable = (1 << 2);
-	}
 
 	/* Assert SRS signal */
 	__raw_writew(wcr_enable, wdog_base);
@@ -55,7 +53,7 @@ void mxc_restart(char mode, const char *cmd)
 	/* wait for reset to assert... */
 	mdelay(500);
 
-	printk(KERN_ERR "Watchdog reset failed to assert reset\n");
+	pr_err("%s: Watchdog reset failed to assert reset\n", __func__);
 
 	/* delay to allow the serial port to show the message */
 	mdelay(50);
@@ -64,7 +62,16 @@ void mxc_restart(char mode, const char *cmd)
 	soft_restart(0);
 }
 
-void mxc_arch_reset_init(void __iomem *base)
+void __init mxc_arch_reset_init(void __iomem *base)
 {
 	wdog_base = base;
+
+	wdog_clk = clk_get_sys("imx2-wdt.0", NULL);
+	if (IS_ERR(wdog_clk)) {
+		pr_warn("%s: failed to get wdog clock\n", __func__);
+		wdog_clk = NULL;
+		return;
+	}
+
+	clk_prepare(wdog_clk);
 }