[ARM] S3C64XX: Initial support for PM (suspend to RAM)

Add the initial support for the S3C64XX based systems to use
suspend-to-RAM to sleep.

Includes basic debugging for use with the SMDK6410 usign the
LEDs on the baseboard.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

arch/arm/mach-s3c6400/include/mach/regs-clock.h

@@ -0,0 +1,16 @@
+/* linux/arch/arm/mach-s3c6400/include/mach/regs-clock.h
+ *
+ * Copyright 2008 Openmoko, Inc.
+ * Copyright 2008 Simtec Electronics
+ *	http://armlinux.simtec.co.uk/
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C64XX - clock register compatibility with s3c24xx
+ *
+ * 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 <plat/regs-clock.h>
+

arch/arm/plat-s3c/Kconfig

@@ -71,6 +71,15 @@ config S3C2410_PM_DEBUG
 	  Resume code. See <file:Documentation/arm/Samsung-S3C24XX/Suspend.txt>
 	  for more information.
 
+config S3C_PM_DEBUG_LED_SMDK
+       bool "SMDK LED suspend/resume debugging"
+       depends on PM && (MACH_SMDK6410)
+       help
+         Say Y here to enable the use of the SMDK LEDs on the baseboard
+	 for debugging of the state of the suspend and resume process.
+
+	 Note, this currently only works for S3C64XX based SMDK boards.
+
 config S3C2410_PM_CHECK
 	bool "S3C2410 PM Suspend Memory CRC"
 	depends on PM && CRC32

arch/arm/plat-s3c/include/plat/pm.h

@@ -127,6 +127,18 @@ extern void s3c_pm_dbg(const char *msg, ...);
 #define S3C_PMDBG(fmt...) printk(KERN_DEBUG fmt)
 #endif
 
+#ifdef CONFIG_S3C_PM_DEBUG_LED_SMDK
+/**
+ * s3c_pm_debug_smdkled() - Debug PM suspend/resume via SMDK Board LEDs
+ * @set: set bits for the state of the LEDs
+ * @clear: clear bits for the state of the LEDs.
+ */
+extern void s3c_pm_debug_smdkled(u32 set, u32 clear);
+
+#else
+static inline void s3c_pm_debug_smdkled(u32 set, u32 clear) { }
+#endif /* CONFIG_S3C_PM_DEBUG_LED_SMDK */
+
 /* suspend memory checking */
 
 #ifdef CONFIG_S3C2410_PM_CHECK

arch/arm/plat-s3c/pm.c

@@ -21,11 +21,10 @@
 
 #include <asm/cacheflush.h>
 #include <mach/hardware.h>
+#include <mach/map.h>
 
 #include <plat/regs-serial.h>
 #include <mach/regs-clock.h>
-#include <mach/regs-gpio.h>
-#include <mach/regs-mem.h>
 #include <mach/regs-irq.h>
 #include <asm/irq.h>
 
@@ -326,6 +325,9 @@ static int s3c_pm_enter(suspend_state_t state)
 
 	S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
 
+	/* LEDs should now be 1110 */
+	s3c_pm_debug_smdkled(1 << 1, 0);
+
 	s3c_pm_check_restore();
 
 	/* ok, let's return from sleep */

arch/arm/plat-s3c64xx/Makefile

@@ -24,6 +24,11 @@ obj-y				+= gpiolib.o
 obj-$(CONFIG_CPU_S3C6400_INIT)	+= s3c6400-init.o
 obj-$(CONFIG_CPU_S3C6400_CLOCK)	+= s3c6400-clock.o
 
+# PM support
+
+obj-$(CONFIG_PM)		+= pm.o
+obj-$(CONFIG_PM)		+= sleep.o
+
 # Device setup
 
 obj-$(CONFIG_S3C64XX_SETUP_I2C0) += setup-i2c0.o

arch/arm/plat-s3c64xx/include/plat/irqs.h

@@ -157,6 +157,7 @@
 
 #define S3C_EINT(x)		((x) + S3C_IRQ_EINT_BASE)
 #define IRQ_EINT(x)		S3C_EINT(x)
+#define IRQ_EINT_BIT(x)		((x) - S3C_EINT(0))
 
 /* Next the external interrupt groups. These are similar to the IRQ_EINT(x)
  * that they are sourced from the GPIO pins but with a different scheme for

arch/arm/plat-s3c64xx/include/plat/pm-core.h

@@ -0,0 +1,98 @@
+/* linux/arch/arm/plat-s3c64xx/include/plat/pm-core.h
+ *
+ * Copyright 2008 Openmoko, Inc.
+ * Copyright 2008 Simtec Electronics
+ *      Ben Dooks <ben@simtec.co.uk>
+ *      http://armlinux.simtec.co.uk/
+ *
+ * S3C64XX - PM core support for arch/arm/plat-s3c/pm.c
+ *
+ * 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 <plat/regs-gpio.h>
+
+static inline void s3c_pm_debug_init_uart(void)
+{
+	u32 tmp = __raw_readl(S3C_PCLK_GATE);
+
+	/* As a note, since the S3C64XX 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 |= S3C_CLKCON_PCLK_UART0;
+	tmp |= S3C_CLKCON_PCLK_UART1;
+	tmp |= S3C_CLKCON_PCLK_UART2;
+	tmp |= S3C_CLKCON_PCLK_UART3;
+
+	__raw_writel(tmp, S3C_PCLK_GATE);
+	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(S3C64XX_EINT0PEND), S3C64XX_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 << 28) - 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;
+
+	/* S3C64XX UART blocks only support level interrupts, so ensure that
+	 * when we restore unused UART blocks we force the level interrupt
+	 * settigs. */
+	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 an 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;
+	}
+}

arch/arm/plat-s3c64xx/include/plat/regs-clock.h

@@ -32,6 +32,7 @@
 #define S3C_HCLK_GATE		S3C_CLKREG(0x30)
 #define S3C_PCLK_GATE		S3C_CLKREG(0x34)
 #define S3C_SCLK_GATE		S3C_CLKREG(0x38)
+#define S3C_MEM0_GATE		S3C_CLKREG(0x3C)
 
 /* CLKDIV0 */
 #define S3C6400_CLKDIV0_MFC_MASK	(0xf << 28)

arch/arm/plat-s3c64xx/irq-eint.c

@@ -14,6 +14,7 @@
 
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
+#include <linux/sysdev.h>
 #include <linux/gpio.h>
 #include <linux/irq.h>
 #include <linux/io.h>
@@ -26,6 +27,7 @@
 
 #include <mach/map.h>
 #include <plat/cpu.h>
+#include <plat/pm.h>
 
 #define eint_offset(irq)	((irq) - IRQ_EINT(0))
 #define eint_irq_to_bit(irq)	(1 << eint_offset(irq))
@@ -134,6 +136,7 @@ static struct irq_chip s3c_irq_eint = {
 	.mask_ack	= s3c_irq_eint_maskack,
 	.ack		= s3c_irq_eint_ack,
 	.set_type	= s3c_irq_eint_set_type,
+	.set_wake	= s3c_irqext_wake,
 };
 
 /* s3c_irq_demux_eint