1 /* linux/arch/arm/plat-s3c/pm.c
3 * Copyright 2008 Openmoko, Inc.
4 * Copyright 2004-2008 Simtec Electronics
5 * Ben Dooks <ben@simtec.co.uk>
6 * http://armlinux.simtec.co.uk/
8 * S3C common power management (suspend to ram) support.
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
15 #include <linux/init.h>
16 #include <linux/suspend.h>
17 #include <linux/errno.h>
18 #include <linux/delay.h>
20 #include <linux/serial_core.h>
23 #include <asm/cacheflush.h>
24 #include <asm/suspend.h>
26 #include <plat/regs-serial.h>
28 #ifdef CONFIG_SAMSUNG_ATAGS
29 #include <mach/hardware.h>
31 #include <mach/regs-clock.h>
32 #include <mach/regs-irq.h>
33 #include <mach/irqs.h>
39 #include <mach/pm-core.h>
41 /* for external use */
43 unsigned long s3c_pm_flags;
47 * This code supports debug output to the low level UARTs for use on
48 * resume before the console layer is available.
51 #ifdef CONFIG_SAMSUNG_PM_DEBUG
52 extern void printascii(const char *);
54 void s3c_pm_dbg(const char *fmt, ...)
60 vsnprintf(buff, sizeof(buff), fmt, va);
66 static inline void s3c_pm_debug_init(void)
68 /* restart uart clocks so we can use them to output */
69 s3c_pm_debug_init_uart();
73 #define s3c_pm_debug_init() do { } while(0)
75 #endif /* CONFIG_SAMSUNG_PM_DEBUG */
77 /* Save the UART configurations if we are configured for debug. */
79 unsigned char pm_uart_udivslot;
81 #ifdef CONFIG_SAMSUNG_PM_DEBUG
83 static struct pm_uart_save uart_save[CONFIG_SERIAL_SAMSUNG_UARTS];
85 static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
87 void __iomem *regs = S3C_VA_UARTx(uart);
89 save->ulcon = __raw_readl(regs + S3C2410_ULCON);
90 save->ucon = __raw_readl(regs + S3C2410_UCON);
91 save->ufcon = __raw_readl(regs + S3C2410_UFCON);
92 save->umcon = __raw_readl(regs + S3C2410_UMCON);
93 save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
96 save->udivslot = __raw_readl(regs + S3C2443_DIVSLOT);
98 S3C_PMDBG("UART[%d]: ULCON=%04x, UCON=%04x, UFCON=%04x, UBRDIV=%04x\n",
99 uart, save->ulcon, save->ucon, save->ufcon, save->ubrdiv);
102 static void s3c_pm_save_uarts(void)
104 struct pm_uart_save *save = uart_save;
107 for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
108 s3c_pm_save_uart(uart, save);
111 static void s3c_pm_restore_uart(unsigned int uart, struct pm_uart_save *save)
113 void __iomem *regs = S3C_VA_UARTx(uart);
115 s3c_pm_arch_update_uart(regs, save);
117 __raw_writel(save->ulcon, regs + S3C2410_ULCON);
118 __raw_writel(save->ucon, regs + S3C2410_UCON);
119 __raw_writel(save->ufcon, regs + S3C2410_UFCON);
120 __raw_writel(save->umcon, regs + S3C2410_UMCON);
121 __raw_writel(save->ubrdiv, regs + S3C2410_UBRDIV);
123 if (pm_uart_udivslot)
124 __raw_writel(save->udivslot, regs + S3C2443_DIVSLOT);
127 static void s3c_pm_restore_uarts(void)
129 struct pm_uart_save *save = uart_save;
132 for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
133 s3c_pm_restore_uart(uart, save);
136 static void s3c_pm_save_uarts(void) { }
137 static void s3c_pm_restore_uarts(void) { }
140 /* The IRQ ext-int code goes here, it is too small to currently bother
141 * with its own file. */
143 unsigned long s3c_irqwake_intmask = 0xffffffffL;
144 unsigned long s3c_irqwake_eintmask = 0xffffffffL;
146 int s3c_irqext_wake(struct irq_data *data, unsigned int state)
148 unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
150 if (!(s3c_irqwake_eintallow & bit))
153 printk(KERN_INFO "wake %s for irq %d\n",
154 state ? "enabled" : "disabled", data->irq);
157 s3c_irqwake_eintmask |= bit;
159 s3c_irqwake_eintmask &= ~bit;
164 /* helper functions to save and restore register state */
167 * s3c_pm_do_save() - save a set of registers for restoration on resume.
168 * @ptr: Pointer to an array of registers.
169 * @count: Size of the ptr array.
171 * Run through the list of registers given, saving their contents in the
172 * array for later restoration when we wakeup.
174 void s3c_pm_do_save(struct sleep_save *ptr, int count)
176 for (; count > 0; count--, ptr++) {
177 ptr->val = __raw_readl(ptr->reg);
178 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
183 * s3c_pm_do_restore() - restore register values from the save list.
184 * @ptr: Pointer to an array of registers.
185 * @count: Size of the ptr array.
187 * Restore the register values saved from s3c_pm_do_save().
189 * Note, we do not use S3C_PMDBG() in here, as the system may not have
190 * restore the UARTs state yet
193 void s3c_pm_do_restore(struct sleep_save *ptr, int count)
195 for (; count > 0; count--, ptr++) {
196 printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
197 ptr->reg, ptr->val, __raw_readl(ptr->reg));
199 __raw_writel(ptr->val, ptr->reg);
204 * s3c_pm_do_restore_core() - early restore register values from save list.
206 * This is similar to s3c_pm_do_restore() except we try and minimise the
207 * side effects of the function in case registers that hardware might need
208 * to work has been restored.
210 * WARNING: Do not put any debug in here that may effect memory or use
211 * peripherals, as things may be changing!
214 void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
216 for (; count > 0; count--, ptr++)
217 __raw_writel(ptr->val, ptr->reg);
220 /* s3c2410_pm_show_resume_irqs
222 * print any IRQs asserted at resume time (ie, we woke from)
224 static void __maybe_unused s3c_pm_show_resume_irqs(int start,
232 for (i = 0; i <= 31; i++) {
233 if (which & (1L<<i)) {
234 S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
240 void (*pm_cpu_prep)(void);
241 int (*pm_cpu_sleep)(unsigned long);
243 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
247 * central control for sleep/resume process
250 static int s3c_pm_enter(suspend_state_t state)
253 /* ensure the debug is initialised (if enabled) */
257 S3C_PMDBG("%s(%d)\n", __func__, state);
259 if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
260 printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
264 /* check if we have anything to wake-up with... bad things seem
265 * to happen if you suspend with no wakeup (system will often
266 * require a full power-cycle)
269 if (!of_have_populated_dt() &&
270 !any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
271 !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
272 printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
273 printk(KERN_ERR "%s: Aborting sleep\n", __func__);
277 /* save all necessary core registers not covered by the drivers */
279 if (!of_have_populated_dt()) {
280 samsung_pm_save_gpios();
281 samsung_pm_saved_gpios();
287 /* set the irq configuration for wake */
289 s3c_pm_configure_extint();
291 S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
292 s3c_irqwake_intmask, s3c_irqwake_eintmask);
294 s3c_pm_arch_prepare_irqs();
296 /* call cpu specific preparation */
300 /* flush cache back to ram */
304 s3c_pm_check_store();
306 /* send the cpu to sleep... */
308 s3c_pm_arch_stop_clocks();
310 /* this will also act as our return point from when
311 * we resume as it saves its own register state and restores it
312 * during the resume. */
314 ret = cpu_suspend(0, pm_cpu_sleep);
318 /* restore the system state */
320 s3c_pm_restore_core();
321 s3c_pm_restore_uarts();
323 if (!of_have_populated_dt()) {
324 samsung_pm_restore_gpios();
325 s3c_pm_restored_gpios();
330 /* check what irq (if any) restored the system */
332 s3c_pm_arch_show_resume_irqs();
334 S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
336 /* LEDs should now be 1110 */
337 s3c_pm_debug_smdkled(1 << 1, 0);
339 s3c_pm_check_restore();
341 /* ok, let's return from sleep */
343 S3C_PMDBG("S3C PM Resume (post-restore)\n");
347 static int s3c_pm_prepare(void)
349 /* prepare check area if configured */
351 s3c_pm_check_prepare();
355 static void s3c_pm_finish(void)
357 s3c_pm_check_cleanup();
360 static const struct platform_suspend_ops s3c_pm_ops = {
361 .enter = s3c_pm_enter,
362 .prepare = s3c_pm_prepare,
363 .finish = s3c_pm_finish,
364 .valid = suspend_valid_only_mem,
369 * Attach the power management functions. This should be called
370 * from the board specific initialisation if the board supports
374 int __init s3c_pm_init(void)
376 printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
378 suspend_set_ops(&s3c_pm_ops);