1 files changed, 363 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c/pm.c b/arch/arm/plat-s3c/pm.c
new file mode 100644
index 000000000000..061182ca66e3
--- /dev/null
+++ b/arch/arm/plat-s3c/pm.c
@@ -0,0 +1,363 @@
+/* linux/arch/arm/plat-s3c/pm.c
+ *
+ * Copyright 2008 Openmoko, Inc.
+ * Copyright 2004,2006,2008 Simtec Electronics
+ *      Ben Dooks <ben@simtec.co.uk>
+ *      http://armlinux.simtec.co.uk/
+ *
+ * S3C common power management (suspend to ram) 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/errno.h>
+#include <linux/delay.h>
+#include <linux/serial_core.h>
+#include <linux/io.h>
+
+#include <asm/cacheflush.h>
+#include <mach/hardware.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>
+
+#include <plat/pm.h>
+#include <plat/pm-core.h>
+
+/* for external use */
+
+unsigned long s3c_pm_flags;
+
+/* Debug code:
+ *
+ * This code supports debug output to the low level UARTs for use on
+ * resume before the console layer is available.
+*/
+
+#ifdef CONFIG_S3C2410_PM_DEBUG
+extern void printascii(const char *);
+
+void s3c_pm_dbg(const char *fmt, ...)
+{
+        va_list va;
+        char buff[256];
+
+        va_start(va, fmt);
+        vsprintf(buff, fmt, va);
+        va_end(va);
+
+        printascii(buff);
+}
+
+static inline void s3c_pm_debug_init(void)
+{
+        /* restart uart clocks so we can use them to output */
+        s3c_pm_debug_init_uart();
+}
+
+#else
+#define s3c_pm_debug_init() do { } while(0)
+
+#endif /* CONFIG_S3C2410_PM_DEBUG */
+
+/* Save the UART configurations if we are configured for debug. */
+
+#ifdef CONFIG_S3C2410_PM_DEBUG
+
+struct pm_uart_save uart_save[CONFIG_SERIAL_SAMSUNG_UARTS];
+
+static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
+{
+        void __iomem *regs = S3C_VA_UARTx(uart);
+
+        save->ulcon = __raw_readl(regs + S3C2410_ULCON);
+        save->ucon = __raw_readl(regs + S3C2410_UCON);
+        save->ufcon = __raw_readl(regs + S3C2410_UFCON);
+        save->umcon = __raw_readl(regs + S3C2410_UMCON);
+        save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
+}
+
+static void s3c_pm_save_uarts(void)
+{
+        struct pm_uart_save *save = uart_save;
+        unsigned int uart;
+
+        for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
+                s3c_pm_save_uart(uart, save);
+}
+
+static void s3c_pm_restore_uart(unsigned int uart, struct pm_uart_save *save)
+{
+        void __iomem *regs = S3C_VA_UARTx(uart);
+
+        __raw_writel(save->ulcon, regs + S3C2410_ULCON);
+        __raw_writel(save->ucon,  regs + S3C2410_UCON);
+        __raw_writel(save->ufcon, regs + S3C2410_UFCON);
+        __raw_writel(save->umcon, regs + S3C2410_UMCON);
+        __raw_writel(save->ubrdiv, regs + S3C2410_UBRDIV);
+}
+
+static void s3c_pm_restore_uarts(void)
+{
+        struct pm_uart_save *save = uart_save;
+        unsigned int uart;
+
+        for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
+                s3c_pm_restore_uart(uart, save);
+}
+#else
+static void s3c_pm_save_uarts(void) { }
+static void s3c_pm_restore_uarts(void) { }
+#endif
+
+/* The IRQ ext-int code goes here, it is too small to currently bother
+ * with its own file. */
+
+unsigned long s3c_irqwake_intmask       = 0xffffffffL;
+unsigned long s3c_irqwake_eintmask      = 0xffffffffL;
+
+int s3c_irqext_wake(unsigned int irqno, unsigned int state)
+{
+        unsigned long bit = 1L << IRQ_EINT_BIT(irqno);
+
+        if (!(s3c_irqwake_eintallow & bit))
+                return -ENOENT;
+
+        printk(KERN_INFO "wake %s for irq %d\n",
+               state ? "enabled" : "disabled", irqno);
+
+        if (!state)
+                s3c_irqwake_eintmask |= bit;
+        else
+                s3c_irqwake_eintmask &= ~bit;
+
+        return 0;
+}
+
+/* helper functions to save and restore register state */
+
+/**
+ * s3c_pm_do_save() - save a set of registers for restoration on resume.
+ * @ptr: Pointer to an array of registers.
+ * @count: Size of the ptr array.
+ *
+ * Run through the list of registers given, saving their contents in the
+ * array for later restoration when we wakeup.
+ */
+void s3c_pm_do_save(struct sleep_save *ptr, int count)
+{
+        for (; count > 0; count--, ptr++) {
+                ptr->val = __raw_readl(ptr->reg);
+                S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
+        }
+}
+
+/**
+ * s3c_pm_do_restore() - restore register values from the save list.
+ * @ptr: Pointer to an array of registers.
+ * @count: Size of the ptr array.
+ *
+ * Restore the register values saved from s3c_pm_do_save().
+ *
+ * Note, we do not use S3C_PMDBG() in here, as the system may not have
+ * restore the UARTs state yet
+*/
+
+void s3c_pm_do_restore(struct sleep_save *ptr, int count)
+{
+        for (; count > 0; count--, ptr++) {
+                printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
+                       ptr->reg, ptr->val, __raw_readl(ptr->reg));
+
+                __raw_writel(ptr->val, ptr->reg);
+        }
+}
+
+/**
+ * s3c_pm_do_restore_core() - early restore register values from save list.
+ *
+ * This is similar to s3c_pm_do_restore() except we try and minimise the
+ * side effects of the function in case registers that hardware might need
+ * to work has been restored.
+ *
+ * WARNING: Do not put any debug in here that may effect memory or use
+ * peripherals, as things may be changing!
+*/
+
+void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
+{
+        for (; count > 0; count--, ptr++)
+                __raw_writel(ptr->val, ptr->reg);
+}
+
+/* s3c2410_pm_show_resume_irqs
+ *
+ * print any IRQs asserted at resume time (ie, we woke from)
+*/
+static void s3c_pm_show_resume_irqs(int start, unsigned long which,
+                                    unsigned long mask)
+{
+        int i;
+
+        which &= ~mask;
+
+        for (i = 0; i <= 31; i++) {
+                if (which & (1L<<i)) {
+                        S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
+                }
+        }
+}
+
+
+void (*pm_cpu_prep)(void);
+void (*pm_cpu_sleep)(void);
+
+#define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
+
+/* s3c_pm_enter
+ *
+ * central control for sleep/resume process
+*/
+
+static int s3c_pm_enter(suspend_state_t state)
+{
+        static unsigned long regs_save[16];
+
+        /* ensure the debug is initialised (if enabled) */
+
+        s3c_pm_debug_init();
+
+        S3C_PMDBG("%s(%d)\n", __func__, state);
+
+        if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
+                printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
+                return -EINVAL;
+        }
+
+        /* check if we have anything to wake-up with... bad things seem
+         * to happen if you suspend with no wakeup (system will often
+         * require a full power-cycle)
+        */
+
+        if (!any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
+            !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
+                printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
+                printk(KERN_ERR "%s: Aborting sleep\n", __func__);
+                return -EINVAL;
+        }
+
+        /* store the physical address of the register recovery block */
+
+        s3c_sleep_save_phys = virt_to_phys(regs_save);
+
+        S3C_PMDBG("s3c_sleep_save_phys=0x%08lx\n", s3c_sleep_save_phys);
+
+        /* save all necessary core registers not covered by the drivers */
+
+        s3c_pm_save_gpios();
+        s3c_pm_save_uarts();
+        s3c_pm_save_core();
+
+        /* set the irq configuration for wake */
+
+        s3c_pm_configure_extint();
+
+        S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
+            s3c_irqwake_intmask, s3c_irqwake_eintmask);
+
+        s3c_pm_arch_prepare_irqs();
+
+        /* call cpu specific preparation */
+
+        pm_cpu_prep();
+
+        /* flush cache back to ram */
+
+        flush_cache_all();
+
+        s3c_pm_check_store();
+
+        /* send the cpu to sleep... */
+
+        s3c_pm_arch_stop_clocks();
+
+        /* s3c_cpu_save will also act as our return point from when
+         * we resume as it saves its own register state and restores it
+         * during the resume.  */
+
+        s3c_cpu_save(regs_save);
+
+        /* restore the cpu state using the kernel's cpu init code. */
+
+        cpu_init();
+
+        /* restore the system state */
+
+        s3c_pm_restore_core();
+        s3c_pm_restore_uarts();
+        s3c_pm_restore_gpios();
+
+        s3c_pm_debug_init();
+
+        /* check what irq (if any) restored the system */
+
+        s3c_pm_arch_show_resume_irqs();
+
+        S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
+
+        s3c_pm_check_restore();
+
+        /* ok, let's return from sleep */
+
+        S3C_PMDBG("S3C PM Resume (post-restore)\n");
+        return 0;
+}
+
+/* callback from assembly code */
+void s3c_pm_cb_flushcache(void)
+{
+        flush_cache_all();
+}
+
+static int s3c_pm_prepare(void)
+{
+        /* prepare check area if configured */
+
+        s3c_pm_check_prepare();
+        return 0;
+}
+
+static void s3c_pm_finish(void)
+{
+        s3c_pm_check_cleanup();
+}
+
+static struct platform_suspend_ops s3c_pm_ops = {
+        .enter          = s3c_pm_enter,
+        .prepare        = s3c_pm_prepare,
+        .finish         = s3c_pm_finish,
+        .valid          = suspend_valid_only_mem,
+};
+
+/* s3c_pm_init
+ *
+ * Attach the power management functions. This should be called
+ * from the board specific initialisation if the board supports
+ * it.
+*/
+
+int __init s3c_pm_init(void)
+{
+        printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
+
+        suspend_set_ops(&s3c_pm_ops);
+        return 0;
+}