diff options
Diffstat (limited to 'arch/arm/plat-s3c/pm.c')
| -rw-r--r-- | arch/arm/plat-s3c/pm.c | 363 |
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; +} |
