[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>

1 files changed, 186 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c64xx/pm.c b/arch/arm/plat-s3c64xx/pm.c
new file mode 100644
index 000000000000..98190aa364ae
--- /dev/null
+++ b/arch/arm/plat-s3c64xx/pm.c
@@ -0,0 +1,186 @@
+/* linux/arch/arm/plat-s3c64xx/pm.c
+ *
+ * Copyright 2008 Openmoko, Inc.
+ * Copyright 2008 Simtec Electronics
+ *      Ben Dooks <ben@simtec.co.uk>
+ *      http://armlinux.simtec.co.uk/
+ *
+ * S3C64XX CPU PM support.
+ *
+ * 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/init.h>
+#include <linux/suspend.h>
+#include <linux/serial_core.h>
+#include <linux/io.h>
+
+#include <mach/map.h>
+
+#include <plat/pm.h>
+#include <plat/regs-sys.h>
+#include <plat/regs-gpio.h>
+#include <plat/regs-clock.h>
+#include <plat/regs-syscon-power.h>
+#include <plat/regs-gpio-memport.h>
+
+#ifdef CONFIG_S3C_PM_DEBUG_LED_SMDK
+#include <plat/gpio-bank-n.h>
+
+void s3c_pm_debug_smdkled(u32 set, u32 clear)
+{
+        unsigned long flags;
+        u32 reg;
+
+        local_irq_save(flags);
+        reg = __raw_readl(S3C64XX_GPNCON);
+        reg &= ~(S3C64XX_GPN_CONMASK(12) | S3C64XX_GPN_CONMASK(13) |
+                 S3C64XX_GPN_CONMASK(14) | S3C64XX_GPN_CONMASK(15));
+        reg |= S3C64XX_GPN_OUTPUT(12) | S3C64XX_GPN_OUTPUT(13) |
+               S3C64XX_GPN_OUTPUT(14) | S3C64XX_GPN_OUTPUT(15);
+        __raw_writel(reg, S3C64XX_GPNCON);
+
+        reg = __raw_readl(S3C64XX_GPNDAT);
+        reg &= ~(clear << 12);
+        reg |= set << 12;
+        __raw_writel(reg, S3C64XX_GPNDAT);
+
+        local_irq_restore(flags);
+}
+#endif
+
+static struct sleep_save core_save[] = {
+        SAVE_ITEM(S3C_APLL_LOCK),
+        SAVE_ITEM(S3C_MPLL_LOCK),
+        SAVE_ITEM(S3C_EPLL_LOCK),
+        SAVE_ITEM(S3C_CLK_SRC),
+        SAVE_ITEM(S3C_CLK_DIV0),
+        SAVE_ITEM(S3C_CLK_DIV1),
+        SAVE_ITEM(S3C_CLK_DIV2),
+        SAVE_ITEM(S3C_CLK_OUT),
+        SAVE_ITEM(S3C_HCLK_GATE),
+        SAVE_ITEM(S3C_PCLK_GATE),
+        SAVE_ITEM(S3C_SCLK_GATE),
+        SAVE_ITEM(S3C_MEM0_GATE),
+
+        SAVE_ITEM(S3C_EPLL_CON1),
+        SAVE_ITEM(S3C_EPLL_CON0),
+
+        SAVE_ITEM(S3C64XX_MEM0DRVCON),
+        SAVE_ITEM(S3C64XX_MEM1DRVCON),
+
+#ifndef CONFIG_CPU_FREQ
+        SAVE_ITEM(S3C_APLL_CON),
+        SAVE_ITEM(S3C_MPLL_CON),
+#endif
+};
+
+static struct sleep_save misc_save[] = {
+        SAVE_ITEM(S3C64XX_AHB_CON0),
+        SAVE_ITEM(S3C64XX_AHB_CON1),
+        SAVE_ITEM(S3C64XX_AHB_CON2),
+        
+        SAVE_ITEM(S3C64XX_SPCON),
+
+        SAVE_ITEM(S3C64XX_MEM0CONSTOP),
+        SAVE_ITEM(S3C64XX_MEM1CONSTOP),
+        SAVE_ITEM(S3C64XX_MEM0CONSLP0),
+        SAVE_ITEM(S3C64XX_MEM0CONSLP1),
+        SAVE_ITEM(S3C64XX_MEM1CONSLP),
+};
+
+void s3c_pm_configure_extint(void)
+{
+        __raw_writel(s3c_irqwake_eintmask, S3C64XX_EINT_MASK);
+}
+
+void s3c_pm_save_gpios(void)
+{
+        /* currently, unless the bootloader does something really stupid
+         * the gpio blocks should be maintained over their sleep.
+         */
+}
+
+void s3c_pm_restore_gpios(void)
+{
+}
+
+void s3c_pm_restore_core(void)
+{
+        __raw_writel(0, S3C64XX_EINT_MASK);
+
+        s3c_pm_debug_smdkled(1 << 2, 0);
+
+        s3c_pm_do_restore_core(core_save, ARRAY_SIZE(core_save));
+        s3c_pm_do_restore(misc_save, ARRAY_SIZE(misc_save));
+}
+
+void s3c_pm_save_core(void)
+{
+        s3c_pm_do_save(misc_save, ARRAY_SIZE(misc_save));
+        s3c_pm_do_save(core_save, ARRAY_SIZE(core_save));
+}
+
+/* since both s3c6400 and s3c6410 share the same sleep pm calls, we
+ * put the per-cpu code in here until any new cpu comes along and changes
+ * this.
+ */
+
+#include <plat/regs-gpio.h>
+
+static void s3c64xx_cpu_suspend(void)
+{
+        unsigned long tmp;
+
+        /* set our standby method to sleep */
+
+        tmp = __raw_readl(S3C64XX_PWR_CFG);
+        tmp &= ~S3C64XX_PWRCFG_CFG_WFI_MASK;
+        tmp |= S3C64XX_PWRCFG_CFG_WFI_SLEEP;
+        __raw_writel(tmp, S3C64XX_PWR_CFG);
+
+        /* clear any old wakeup */
+
+        __raw_writel(__raw_readl(S3C64XX_WAKEUP_STAT),
+                     S3C64XX_WAKEUP_STAT);
+
+        /* set the LED state to 0110 over sleep */
+        s3c_pm_debug_smdkled(3 << 1, 0xf);
+
+        /* issue the standby signal into the pm unit. Note, we
+         * issue a write-buffer drain just in case */
+
+        tmp = 0;
+
+        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?");
+}
+
+static void s3c64xx_pm_prepare(void)
+{
+        /* store address of resume. */
+        __raw_writel(virt_to_phys(s3c_cpu_resume), S3C64XX_INFORM0);
+
+        /* ensure previous wakeup state is cleared before sleeping */
+        __raw_writel(__raw_readl(S3C64XX_WAKEUP_STAT), S3C64XX_WAKEUP_STAT);
+}
+
+static int s3c64xx_pm_init(void)
+{
+        pm_cpu_prep = s3c64xx_pm_prepare;
+        pm_cpu_sleep = s3c64xx_cpu_suspend;
+        pm_uart_udivslot = 1;
+        return 0;
+}
+
+arch_initcall(s3c64xx_pm_init);