ARM: S5P64X0: Add Power Management support

Add suspend-to-ram support for SMDK6440/50
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/Kconfig

@@ -2093,7 +2093,7 @@ menu "Power management options"
 source "kernel/power/Kconfig"
 
 config ARCH_SUSPEND_POSSIBLE
-	depends on !ARCH_S5P64X0 && !ARCH_S5PC100
+	depends on !ARCH_S5PC100
 	depends on CPU_ARM920T || CPU_ARM926T || CPU_SA1100 || \
 		CPU_V6 || CPU_V6K || CPU_V7 || CPU_XSC3 || CPU_XSCALE
 	def_bool y

arch/arm/mach-s5p64x0/Kconfig

@@ -11,6 +11,8 @@ config CPU_S5P6440
 	bool
 	select SAMSUNG_DMADEV
 	select S5P_HRT
+	select S5P_SLEEP if PM
+	select SAMSUNG_WAKEMASK if PM
 	help
 	  Enable S5P6440 CPU support
 
@@ -18,6 +20,8 @@ config CPU_S5P6450
 	bool
 	select SAMSUNG_DMADEV
 	select S5P_HRT
+	select S5P_SLEEP if PM
+	select SAMSUNG_WAKEMASK if PM
 	help
 	  Enable S5P6450 CPU support
 

arch/arm/mach-s5p64x0/Makefile

@@ -16,6 +16,7 @@ obj-$(CONFIG_ARCH_S5P64X0)	+= cpu.o init.o clock.o dma.o
 obj-$(CONFIG_ARCH_S5P64X0)	+= setup-i2c0.o irq-eint.o
 obj-$(CONFIG_CPU_S5P6440)	+= clock-s5p6440.o
 obj-$(CONFIG_CPU_S5P6450)	+= clock-s5p6450.o
+obj-$(CONFIG_PM)		+= pm.o irq-pm.o
 
 # machine support
 

arch/arm/mach-s5p64x0/include/mach/map.h

@@ -88,5 +88,6 @@
 #define S5P_PA_UART5		S5P6450_PA_UART(5)
 
 #define S5P_SZ_UART		SZ_256
+#define S3C_VA_UARTx(x)		(S3C_VA_UART + ((x) * S3C_UART_OFFSET))
 
 #endif /* __ASM_ARCH_MAP_H */

arch/arm/mach-s5p64x0/include/mach/pm-core.h

+/* linux/arch/arm/mach-s5p64x0/include/mach/pm-core.h
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * S5P64X0 - PM core support for arch/arm/plat-samsung/pm.c
+ *
+ * Based on PM core support for S3C64XX by Ben Dooks
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <mach/regs-gpio.h>
+
+static inline void s3c_pm_debug_init_uart(void)
+{
+	u32 tmp = __raw_readl(S5P64X0_CLK_GATE_PCLK);
+
+	/*
+	 * As a note, since the S5P64X0 UARTs generally have multiple
+	 * clock sources, we simply enable PCLK at the moment and hope
+	 * that the resume settings for the UART are suitable for the
+	 * use with PCLK.
+	 */
+	tmp |= S5P64X0_CLK_GATE_PCLK_UART0;
+	tmp |= S5P64X0_CLK_GATE_PCLK_UART1;
+	tmp |= S5P64X0_CLK_GATE_PCLK_UART2;
+	tmp |= S5P64X0_CLK_GATE_PCLK_UART3;
+
+	__raw_writel(tmp, S5P64X0_CLK_GATE_PCLK);
+	udelay(10);
+}
+
+static inline void s3c_pm_arch_prepare_irqs(void)
+{
+	/* VIC should have already been taken care of */
+
+	/* clear any pending EINT0 interrupts */
+	__raw_writel(__raw_readl(S5P64X0_EINT0PEND), S5P64X0_EINT0PEND);
+}
+
+static inline void s3c_pm_arch_stop_clocks(void) { }
+static inline void s3c_pm_arch_show_resume_irqs(void) { }
+
+/*
+ * make these defines, we currently do not have any need to change
+ * the IRQ wake controls depending on the CPU we are running on
+ */
+#define s3c_irqwake_eintallow	((1 << 16) - 1)
+#define s3c_irqwake_intallow	(~0)
+
+static inline void s3c_pm_arch_update_uart(void __iomem *regs,
+					struct pm_uart_save *save)
+{
+	u32 ucon = __raw_readl(regs + S3C2410_UCON);
+	u32 ucon_clk = ucon & S3C6400_UCON_CLKMASK;
+	u32 save_clk = save->ucon & S3C6400_UCON_CLKMASK;
+	u32 new_ucon;
+	u32 delta;
+
+	/*
+	 * S5P64X0 UART blocks only support level interrupts, so ensure that
+	 * when we restore unused UART blocks we force the level interrupt
+	 * settings.
+	 */
+	save->ucon |= S3C2410_UCON_TXILEVEL | S3C2410_UCON_RXILEVEL;
+
+	/*
+	 * We have a constraint on changing the clock type of the UART
+	 * between UCLKx and PCLK, so ensure that when we restore UCON
+	 * that the CLK field is correctly modified if the bootloader
+	 * has changed anything.
+	 */
+	if (ucon_clk != save_clk) {
+		new_ucon = save->ucon;
+		delta = ucon_clk ^ save_clk;
+
+		/*
+		 * change from UCLKx => wrong PCLK,
+		 * either UCLK can be tested for by a bit-test
+		 * with UCLK0
+		 */
+		if (ucon_clk & S3C6400_UCON_UCLK0 &&
+		!(save_clk & S3C6400_UCON_UCLK0) &&
+		delta & S3C6400_UCON_PCLK2) {
+			new_ucon &= ~S3C6400_UCON_UCLK0;
+		} else if (delta == S3C6400_UCON_PCLK2) {
+			/*
+			 * as a precaution, don't change from
+			 * PCLK2 => PCLK or vice-versa
+			 */
+			new_ucon ^= S3C6400_UCON_PCLK2;
+		}
+
+		S3C_PMDBG("ucon change %04x => %04x (save=%04x)\n",
+			ucon, new_ucon, save->ucon);
+		save->ucon = new_ucon;
+	}
+}
+
+static inline void s3c_pm_restored_gpios(void)
+{
+	/* ensure sleep mode has been cleared from the system */
+	__raw_writel(0, S5P64X0_SLPEN);
+}
+
+static inline void samsung_pm_saved_gpios(void)
+{
+	/*
+	 * turn on the sleep mode and keep it there, as it seems that during
+	 * suspend the xCON registers get re-set and thus you can end up with
+	 * problems between going to sleep and resuming.
+	 */
+	__raw_writel(S5P64X0_SLPEN_USE_xSLP, S5P64X0_SLPEN);
+}

arch/arm/mach-s5p64x0/include/mach/regs-clock.h

@@ -41,17 +41,50 @@
 #define S5P6450_DPLL_CON		S5P_CLKREG(0x50)
 #define S5P6450_DPLL_CON_K		S5P_CLKREG(0x54)
 
+#define S5P64X0_AHB_CON0		S5P_CLKREG(0x100)
 #define S5P64X0_CLK_SRC1		S5P_CLKREG(0x10C)
 
 #define S5P64X0_SYS_ID			S5P_CLKREG(0x118)
 #define S5P64X0_SYS_OTHERS		S5P_CLKREG(0x11C)
 
 #define S5P64X0_PWR_CFG			S5P_CLKREG(0x804)
+#define S5P64X0_EINT_WAKEUP_MASK	S5P_CLKREG(0x808)
+#define S5P64X0_SLEEP_CFG		S5P_CLKREG(0x818)
+#define S5P64X0_PWR_STABLE		S5P_CLKREG(0x828)
+
 #define S5P64X0_OTHERS			S5P_CLKREG(0x900)
+#define S5P64X0_WAKEUP_STAT		S5P_CLKREG(0x908)
+
+#define S5P64X0_INFORM0			S5P_CLKREG(0xA00)
 
 #define S5P64X0_CLKDIV0_HCLK_SHIFT	(8)
 #define S5P64X0_CLKDIV0_HCLK_MASK	(0xF << S5P64X0_CLKDIV0_HCLK_SHIFT)
 
+/* HCLK GATE Registers */
+#define S5P64X0_CLK_GATE_HCLK1_FIMGVG	(1 << 2)
+#define S5P64X0_CLK_GATE_SCLK1_FIMGVG	(1 << 2)
+
+/* PCLK GATE Registers */
+#define S5P64X0_CLK_GATE_PCLK_UART3	(1 << 4)
+#define S5P64X0_CLK_GATE_PCLK_UART2	(1 << 3)
+#define S5P64X0_CLK_GATE_PCLK_UART1	(1 << 2)
+#define S5P64X0_CLK_GATE_PCLK_UART0	(1 << 1)
+
+#define S5P64X0_PWR_CFG_MMC1_DISABLE		(1 << 15)
+#define S5P64X0_PWR_CFG_MMC0_DISABLE		(1 << 14)
+#define S5P64X0_PWR_CFG_RTC_TICK_DISABLE	(1 << 11)
+#define S5P64X0_PWR_CFG_RTC_ALRM_DISABLE	(1 << 10)
+#define S5P64X0_PWR_CFG_WFI_MASK		(3 << 5)
+#define S5P64X0_PWR_CFG_WFI_SLEEP		(3 << 5)
+
+#define S5P64X0_SLEEP_CFG_OSC_EN	(1 << 0)
+
+#define S5P64X0_PWR_STABLE_PWR_CNT_VAL4	(4 << 0)
+
+#define S5P6450_OTHERS_DISABLE_INT	(1 << 31)
+#define S5P64X0_OTHERS_RET_UART		(1 << 26)
+#define S5P64X0_OTHERS_RET_MMC1		(1 << 25)
+#define S5P64X0_OTHERS_RET_MMC0		(1 << 24)
 #define S5P64X0_OTHERS_USB_SIG_MASK	(1 << 16)
 
 /* Compatibility defines */

arch/arm/mach-s5p64x0/include/mach/regs-gpio.h

@@ -37,15 +37,32 @@
 #define S5P64X0_SPCON0			(S5P_VA_GPIO + 0x1A0)
 #define S5P64X0_SPCON0_LCD_SEL_MASK	(0x3 << 0)
 #define S5P64X0_SPCON0_LCD_SEL_RGB	(0x1 << 0)
+#define S5P64X0_SPCON1			(S5P_VA_GPIO + 0x2B0)
+
+#define S5P64X0_MEM0CONSLP0		(S5P_VA_GPIO + 0x1C0)
+#define S5P64X0_MEM0CONSLP1		(S5P_VA_GPIO + 0x1C4)
+#define S5P64X0_MEM0DRVCON		(S5P_VA_GPIO + 0x1D0)
+#define S5P64X0_MEM1DRVCON		(S5P_VA_GPIO + 0x1D4)
+
+#define S5P64X0_EINT12CON		(S5P_VA_GPIO + 0x200)
+#define S5P64X0_EINT12FLTCON		(S5P_VA_GPIO + 0x220)
+#define S5P64X0_EINT12MASK		(S5P_VA_GPIO + 0x240)
 
 /* External interrupt control registers for group0 */
 
 #define EINT0CON0_OFFSET		(0x900)
+#define EINT0FLTCON0_OFFSET		(0x910)
+#define EINT0FLTCON1_OFFSET		(0x914)
 #define EINT0MASK_OFFSET		(0x920)
 #define EINT0PEND_OFFSET		(0x924)
 
 #define S5P64X0_EINT0CON0		(S5P_VA_GPIO + EINT0CON0_OFFSET)
+#define S5P64X0_EINT0FLTCON0		(S5P_VA_GPIO + EINT0FLTCON0_OFFSET)
+#define S5P64X0_EINT0FLTCON1		(S5P_VA_GPIO + EINT0FLTCON1_OFFSET)
 #define S5P64X0_EINT0MASK		(S5P_VA_GPIO + EINT0MASK_OFFSET)
 #define S5P64X0_EINT0PEND		(S5P_VA_GPIO + EINT0PEND_OFFSET)
 
+#define S5P64X0_SLPEN			(S5P_VA_GPIO + 0x930)
+#define S5P64X0_SLPEN_USE_xSLP		(1 << 0)
+
 #endif /* __ASM_ARCH_REGS_GPIO_H */

arch/arm/mach-s5p64x0/irq-eint.c

@@ -20,6 +20,7 @@
 #include <plat/cpu.h>
 #include <plat/regs-irqtype.h>
 #include <plat/gpio-cfg.h>
+#include <plat/pm.h>
 
 #include <mach/regs-gpio.h>
 #include <mach/regs-clock.h>
@@ -134,6 +135,7 @@ static int s5p64x0_alloc_gc(void)
 	ct->chip.irq_mask = irq_gc_mask_set_bit;
 	ct->chip.irq_unmask = irq_gc_mask_clr_bit;
 	ct->chip.irq_set_type = s5p64x0_irq_eint_set_type;
+	ct->chip.irq_set_wake = s3c_irqext_wake;
 	ct->regs.ack = EINT0PEND_OFFSET;
 	ct->regs.mask = EINT0MASK_OFFSET;
 	irq_setup_generic_chip(gc, IRQ_MSK(16), IRQ_GC_INIT_MASK_CACHE,

arch/arm/mach-s5p64x0/irq-pm.c

+/* linux/arch/arm/mach-s5p64x0/irq-pm.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * S5P64X0 - Interrupt handling Power Management
+ *
+ * Based on arch/arm/mach-s3c64xx/irq-pm.c by Ben Dooks
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/syscore_ops.h>
+#include <linux/serial_core.h>
+#include <linux/io.h>
+
+#include <plat/regs-serial.h>
+#include <plat/pm.h>
+
+#include <mach/regs-gpio.h>
+
+static struct sleep_save irq_save[] = {
+	SAVE_ITEM(S5P64X0_EINT0CON0),
+	SAVE_ITEM(S5P64X0_EINT0FLTCON0),
+	SAVE_ITEM(S5P64X0_EINT0FLTCON1),
+	SAVE_ITEM(S5P64X0_EINT0MASK),
+};
+
+static struct irq_grp_save {
+	u32	con;
+	u32	fltcon;
+	u32	mask;
+} eint_grp_save[4];
+
+static u32 irq_uart_mask[CONFIG_SERIAL_SAMSUNG_UARTS];
+
+static int s5p64x0_irq_pm_suspend(void)
+{
+	struct irq_grp_save *grp = eint_grp_save;
+	int i;
+
+	S3C_PMDBG("%s: suspending IRQs\n", __func__);
+
+	s3c_pm_do_save(irq_save, ARRAY_SIZE(irq_save));
+
+	for (i = 0; i < CONFIG_SERIAL_SAMSUNG_UARTS; i++)
+		irq_uart_mask[i] = __raw_readl(S3C_VA_UARTx(i) + S3C64XX_UINTM);
+
+	for (i = 0; i < ARRAY_SIZE(eint_grp_save); i++, grp++) {
+		grp->con = __raw_readl(S5P64X0_EINT12CON + (i * 4));
+		grp->mask = __raw_readl(S5P64X0_EINT12MASK + (i * 4));
+		grp->fltcon = __raw_readl(S5P64X0_EINT12FLTCON + (i * 4));
+	}
+
+	return 0;
+}
+
+static void s5p64x0_irq_pm_resume(void)
+{
+	struct irq_grp_save *grp = eint_grp_save;
+	int i;
+
+	S3C_PMDBG("%s: resuming IRQs\n", __func__);
+
+	s3c_pm_do_restore(irq_save, ARRAY_SIZE(irq_save));
+
+	for (i = 0; i < CONFIG_SERIAL_SAMSUNG_UARTS; i++)
+		__raw_writel(irq_uart_mask[i], S3C_VA_UARTx(i) + S3C64XX_UINTM);
+
+	for (i = 0; i < ARRAY_SIZE(eint_grp_save); i++, grp++) {
+		__raw_writel(grp->con, S5P64X0_EINT12CON + (i * 4));
+		__raw_writel(grp->mask, S5P64X0_EINT12MASK + (i * 4));
+		__raw_writel(grp->fltcon, S5P64X0_EINT12FLTCON + (i * 4));
+	}
+
+	S3C_PMDBG("%s: IRQ configuration restored\n", __func__);
+}
+
+static struct syscore_ops s5p64x0_irq_syscore_ops = {
+	.suspend = s5p64x0_irq_pm_suspend,
+	.resume  = s5p64x0_irq_pm_resume,
+};
+
+static int __init s5p64x0_syscore_init(void)
+{
+	register_syscore_ops(&s5p64x0_irq_syscore_ops);
+
+	return 0;
+}
+core_initcall(s5p64x0_syscore_init);

arch/arm/mach-s5p64x0/pm.c

+/* linux/arch/arm/mach-s5p64x0/pm.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * S5P64X0 Power Management Support
+ *
+ * Based on arch/arm/mach-s3c64xx/pm.c by Ben Dooks
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/suspend.h>
+#include <linux/syscore_ops.h>
+#include <linux/io.h>
+
+#include <plat/cpu.h>
+#include <plat/pm.h>
+#include <plat/regs-timer.h>
+#include <plat/wakeup-mask.h>
+
+#include <mach/regs-clock.h>
+#include <mach/regs-gpio.h>
+
+static struct sleep_save s5p64x0_core_save[] = {
+	SAVE_ITEM(S5P64X0_APLL_CON),
+	SAVE_ITEM(S5P64X0_MPLL_CON),
+	SAVE_ITEM(S5P64X0_EPLL_CON),
+	SAVE_ITEM(S5P64X0_EPLL_CON_K),
+	SAVE_ITEM(S5P64X0_CLK_SRC0),
+	SAVE_ITEM(S5P64X0_CLK_SRC1),
+	SAVE_ITEM(S5P64X0_CLK_DIV0),
+	SAVE_ITEM(S5P64X0_CLK_DIV1),
+	SAVE_ITEM(S5P64X0_CLK_DIV2),
+	SAVE_ITEM(S5P64X0_CLK_DIV3),
+	SAVE_ITEM(S5P64X0_CLK_GATE_MEM0),
+	SAVE_ITEM(S5P64X0_CLK_GATE_HCLK1),
+	SAVE_ITEM(S5P64X0_CLK_GATE_SCLK1),
+};
+
+static struct sleep_save s5p64x0_misc_save[] = {
+	SAVE_ITEM(S5P64X0_AHB_CON0),
+	SAVE_ITEM(S5P64X0_SPCON0),
+	SAVE_ITEM(S5P64X0_SPCON1),
+	SAVE_ITEM(S5P64X0_MEM0CONSLP0),
+	SAVE_ITEM(S5P64X0_MEM0CONSLP1),
+	SAVE_ITEM(S5P64X0_MEM0DRVCON),
+	SAVE_ITEM(S5P64X0_MEM1DRVCON),
+
+	SAVE_ITEM(S3C64XX_TINT_CSTAT),
+};
+
+/* DPLL is present only in S5P6450 */
+static struct sleep_save s5p6450_core_save[] = {
+	SAVE_ITEM(S5P6450_DPLL_CON),
+	SAVE_ITEM(S5P6450_DPLL_CON_K),
+};
+
+void s3c_pm_configure_extint(void)
+{
+	__raw_writel(s3c_irqwake_eintmask, S5P64X0_EINT_WAKEUP_MASK);
+}
+
+void s3c_pm_restore_core(void)
+{
+	__raw_writel(0, S5P64X0_EINT_WAKEUP_MASK);
+
+	s3c_pm_do_restore_core(s5p64x0_core_save,
+				ARRAY_SIZE(s5p64x0_core_save));
+
+	if (soc_is_s5p6450())
+		s3c_pm_do_restore_core(s5p6450_core_save,
+				ARRAY_SIZE(s5p6450_core_save));
+
+	s3c_pm_do_restore(s5p64x0_misc_save, ARRAY_SIZE(s5p64x0_misc_save));
+}
+
+void s3c_pm_save_core(void)
+{
+	s3c_pm_do_save(s5p64x0_misc_save, ARRAY_SIZE(s5p64x0_misc_save));
+
+	if (soc_is_s5p6450())
+		s3c_pm_do_save(s5p6450_core_save,
+				ARRAY_SIZE(s5p6450_core_save));
+
+	s3c_pm_do_save(s5p64x0_core_save, ARRAY_SIZE(s5p64x0_core_save));
+}
+
+static int s5p64x0_cpu_suspend(unsigned long arg)
+{
+	unsigned long tmp = 0;
+
+	/*
+	 * Issue the standby signal into the pm unit. Note, we
+	 * issue a write-buffer drain just in case.
+	 */
+	asm("b 1f\n\t"
+	    ".align 5\n\t"
+	    "1:\n\t"
+	    "mcr p15, 0, %0, c7, c10, 5\n\t"
+	    "mcr p15, 0, %0, c7, c10, 4\n\t"
+	    "mcr p15, 0, %0, c7, c0, 4" : : "r" (tmp));
+
+	/* we should never get past here */
+	panic("sleep resumed to originator?");
+}
+
+/* mapping of interrupts to parts of the wakeup mask */
+static struct samsung_wakeup_mask s5p64x0_wake_irqs[] = {
+	{ .irq = IRQ_RTC_ALARM,	.bit = S5P64X0_PWR_CFG_RTC_ALRM_DISABLE, },
+	{ .irq = IRQ_RTC_TIC,	.bit = S5P64X0_PWR_CFG_RTC_TICK_DISABLE, },
+	{ .irq = IRQ_HSMMC0,	.bit = S5P64X0_PWR_CFG_MMC0_DISABLE, },
+	{ .irq = IRQ_HSMMC1,	.bit = S5P64X0_PWR_CFG_MMC1_DISABLE, },
+};
+
+static void s5p64x0_pm_prepare(void)
+{
+	u32 tmp;
+
+	samsung_sync_wakemask(S5P64X0_PWR_CFG,
+			s5p64x0_wake_irqs, ARRAY_SIZE(s5p64x0_wake_irqs));
+
+	/* store the resume address in INFORM0 register */
+	__raw_writel(virt_to_phys(s3c_cpu_resume), S5P64X0_INFORM0);
+
+	/* setup clock gating for FIMGVG block */
+	__raw_writel((__raw_readl(S5P64X0_CLK_GATE_HCLK1) | \
+		(S5P64X0_CLK_GATE_HCLK1_FIMGVG)), S5P64X0_CLK_GATE_HCLK1);
+	__raw_writel((__raw_readl(S5P64X0_CLK_GATE_SCLK1) | \
+		(S5P64X0_CLK_GATE_SCLK1_FIMGVG)), S5P64X0_CLK_GATE_SCLK1);
+
+	/* Configure the stabilization counter with wait time required */
+	__raw_writel(S5P64X0_PWR_STABLE_PWR_CNT_VAL4, S5P64X0_PWR_STABLE);
+
+	/* set WFI to SLEEP mode configuration */
+	tmp = __raw_readl(S5P64X0_SLEEP_CFG);
+	tmp &= ~(S5P64X0_SLEEP_CFG_OSC_EN);
+	__raw_writel(tmp, S5P64X0_SLEEP_CFG);
+
+	tmp = __raw_readl(S5P64X0_PWR_CFG);
+	tmp &= ~(S5P64X0_PWR_CFG_WFI_MASK);
+	tmp |= S5P64X0_PWR_CFG_WFI_SLEEP;
+	__raw_writel(tmp, S5P64X0_PWR_CFG);
+
+	/*
+	 * set OTHERS register to disable interrupt before going to
+	 * sleep. This bit is present only in S5P6450, it is reserved
+	 * in S5P6440.
+	 */
+	if (soc_is_s5p6450()) {
+		tmp = __raw_readl(S5P64X0_OTHERS);
+		tmp |= S5P6450_OTHERS_DISABLE_INT;
+		__raw_writel(tmp, S5P64X0_OTHERS);
+	}
+
+	/* ensure previous wakeup state is cleared before sleeping */
+	__raw_writel(__raw_readl(S5P64X0_WAKEUP_STAT), S5P64X0_WAKEUP_STAT);
+
+}
+
+static int s5p64x0_pm_add(struct sys_device *sysdev)
+{
+	pm_cpu_prep = s5p64x0_pm_prepare;
+	pm_cpu_sleep = s5p64x0_cpu_suspend;
+	pm_uart_udivslot = 1;
+
+	return 0;
+}
+
+static struct sysdev_driver s5p64x0_pm_driver = {
+	.add		= s5p64x0_pm_add,
+};
+
+static __init int s5p64x0_pm_drvinit(void)
+{
+	s3c_pm_init();
+
+	return sysdev_driver_register(&s5p64x0_sysclass, &s5p64x0_pm_driver);
+}
+arch_initcall(s5p64x0_pm_drvinit);
+
+static void s5p64x0_pm_resume(void)
+{
+	u32 tmp;
+
+	tmp = __raw_readl(S5P64X0_OTHERS);
+	tmp |= (S5P64X0_OTHERS_RET_MMC0 | S5P64X0_OTHERS_RET_MMC1 | \
+			S5P64X0_OTHERS_RET_UART);
+	__raw_writel(tmp , S5P64X0_OTHERS);
+}
+
+static struct syscore_ops s5p64x0_pm_syscore_ops = {
+	.resume		= s5p64x0_pm_resume,
+};
+
+static __init int s5p64x0_pm_syscore_init(void)
+{
+	register_syscore_ops(&s5p64x0_pm_syscore_ops);
+
+	return 0;
+}
+arch_initcall(s5p64x0_pm_syscore_init);