1/* linux/arch/arm/plat-s3c/pm.c
2 *
3 * Copyright 2008 Openmoko, Inc.
4 * Copyright 2004-2008 Simtec Electronics
5 *	Ben Dooks <ben@simtec.co.uk>
6 *	http://armlinux.simtec.co.uk/
7 *
8 * S3C common power management (suspend to ram) support.
9 *
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.
13*/
14
15#include <linux/init.h>
16#include <linux/suspend.h>
17#include <linux/errno.h>
18#include <linux/delay.h>
19#include <linux/serial_core.h>
20#include <linux/io.h>
21
22#include <asm/cacheflush.h>
23#include <asm/suspend.h>
24#include <mach/hardware.h>
25#include <mach/map.h>
26
27#include <plat/regs-serial.h>
28#include <mach/regs-clock.h>
29#include <mach/regs-irq.h>
30#include <asm/irq.h>
31
32#include <plat/pm.h>
33#include <mach/pm-core.h>
34
35/* for external use */
36
37unsigned long s3c_pm_flags;
38
39/* Debug code:
40 *
41 * This code supports debug output to the low level UARTs for use on
42 * resume before the console layer is available.
43*/
44
45#ifdef CONFIG_SAMSUNG_PM_DEBUG
46extern void printascii(const char *);
47
48void s3c_pm_dbg(const char *fmt, ...)
49{
50	va_list va;
51	char buff[256];
52
53	va_start(va, fmt);
54	vsprintf(buff, fmt, va);
55	va_end(va);
56
57	printascii(buff);
58}
59
60static inline void s3c_pm_debug_init(void)
61{
62	/* restart uart clocks so we can use them to output */
63	s3c_pm_debug_init_uart();
64}
65
66#else
67#define s3c_pm_debug_init() do { } while(0)
68
69#endif /* CONFIG_SAMSUNG_PM_DEBUG */
70
71/* Save the UART configurations if we are configured for debug. */
72
73unsigned char pm_uart_udivslot;
74
75#ifdef CONFIG_SAMSUNG_PM_DEBUG
76
77struct pm_uart_save uart_save[CONFIG_SERIAL_SAMSUNG_UARTS];
78
79static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
80{
81	void __iomem *regs = S3C_VA_UARTx(uart);
82
83	save->ulcon = __raw_readl(regs + S3C2410_ULCON);
84	save->ucon = __raw_readl(regs + S3C2410_UCON);
85	save->ufcon = __raw_readl(regs + S3C2410_UFCON);
86	save->umcon = __raw_readl(regs + S3C2410_UMCON);
87	save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
88
89	if (pm_uart_udivslot)
90		save->udivslot = __raw_readl(regs + S3C2443_DIVSLOT);
91
92	S3C_PMDBG("UART[%d]: ULCON=%04x, UCON=%04x, UFCON=%04x, UBRDIV=%04x\n",
93		  uart, save->ulcon, save->ucon, save->ufcon, save->ubrdiv);
94}
95
96static void s3c_pm_save_uarts(void)
97{
98	struct pm_uart_save *save = uart_save;
99	unsigned int uart;
100
101	for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
102		s3c_pm_save_uart(uart, save);
103}
104
105static void s3c_pm_restore_uart(unsigned int uart, struct pm_uart_save *save)
106{
107	void __iomem *regs = S3C_VA_UARTx(uart);
108
109	s3c_pm_arch_update_uart(regs, save);
110
111	__raw_writel(save->ulcon, regs + S3C2410_ULCON);
112	__raw_writel(save->ucon,  regs + S3C2410_UCON);
113	__raw_writel(save->ufcon, regs + S3C2410_UFCON);
114	__raw_writel(save->umcon, regs + S3C2410_UMCON);
115	__raw_writel(save->ubrdiv, regs + S3C2410_UBRDIV);
116
117	if (pm_uart_udivslot)
118		__raw_writel(save->udivslot, regs + S3C2443_DIVSLOT);
119}
120
121static void s3c_pm_restore_uarts(void)
122{
123	struct pm_uart_save *save = uart_save;
124	unsigned int uart;
125
126	for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
127		s3c_pm_restore_uart(uart, save);
128}
129#else
130static void s3c_pm_save_uarts(void) { }
131static void s3c_pm_restore_uarts(void) { }
132#endif
133
134/* The IRQ ext-int code goes here, it is too small to currently bother
135 * with its own file. */
136
137unsigned long s3c_irqwake_intmask	= 0xffffffffL;
138unsigned long s3c_irqwake_eintmask	= 0xffffffffL;
139
140int s3c_irqext_wake(struct irq_data *data, unsigned int state)
141{
142	unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
143
144	if (!(s3c_irqwake_eintallow & bit))
145		return -ENOENT;
146
147	printk(KERN_INFO "wake %s for irq %d\n",
148	       state ? "enabled" : "disabled", data->irq);
149
150	if (!state)
151		s3c_irqwake_eintmask |= bit;
152	else
153		s3c_irqwake_eintmask &= ~bit;
154
155	return 0;
156}
157
158/* helper functions to save and restore register state */
159
160/**
161 * s3c_pm_do_save() - save a set of registers for restoration on resume.
162 * @ptr: Pointer to an array of registers.
163 * @count: Size of the ptr array.
164 *
165 * Run through the list of registers given, saving their contents in the
166 * array for later restoration when we wakeup.
167 */
168void s3c_pm_do_save(struct sleep_save *ptr, int count)
169{
170	for (; count > 0; count--, ptr++) {
171		ptr->val = __raw_readl(ptr->reg);
172		S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
173	}
174}
175
176/**
177 * s3c_pm_do_restore() - restore register values from the save list.
178 * @ptr: Pointer to an array of registers.
179 * @count: Size of the ptr array.
180 *
181 * Restore the register values saved from s3c_pm_do_save().
182 *
183 * Note, we do not use S3C_PMDBG() in here, as the system may not have
184 * restore the UARTs state yet
185*/
186
187void s3c_pm_do_restore(struct sleep_save *ptr, int count)
188{
189	for (; count > 0; count--, ptr++) {
190		printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
191		       ptr->reg, ptr->val, __raw_readl(ptr->reg));
192
193		__raw_writel(ptr->val, ptr->reg);
194	}
195}
196
197/**
198 * s3c_pm_do_restore_core() - early restore register values from save list.
199 *
200 * This is similar to s3c_pm_do_restore() except we try and minimise the
201 * side effects of the function in case registers that hardware might need
202 * to work has been restored.
203 *
204 * WARNING: Do not put any debug in here that may effect memory or use
205 * peripherals, as things may be changing!
206*/
207
208void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
209{
210	for (; count > 0; count--, ptr++)
211		__raw_writel(ptr->val, ptr->reg);
212}
213
214/* s3c2410_pm_show_resume_irqs
215 *
216 * print any IRQs asserted at resume time (ie, we woke from)
217*/
218static void __maybe_unused s3c_pm_show_resume_irqs(int start,
219						   unsigned long which,
220						   unsigned long mask)
221{
222	int i;
223
224	which &= ~mask;
225
226	for (i = 0; i <= 31; i++) {
227		if (which & (1L<<i)) {
228			S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
229		}
230	}
231}
232
233
234void (*pm_cpu_prep)(void);
235int (*pm_cpu_sleep)(unsigned long);
236
237#define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
238
239/* s3c_pm_enter
240 *
241 * central control for sleep/resume process
242*/
243
244static int s3c_pm_enter(suspend_state_t state)
245{
246	/* ensure the debug is initialised (if enabled) */
247
248	s3c_pm_debug_init();
249
250	S3C_PMDBG("%s(%d)\n", __func__, state);
251
252	if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
253		printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
254		return -EINVAL;
255	}
256
257	/* check if we have anything to wake-up with... bad things seem
258	 * to happen if you suspend with no wakeup (system will often
259	 * require a full power-cycle)
260	*/
261
262	if (!any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
263	    !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
264		printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
265		printk(KERN_ERR "%s: Aborting sleep\n", __func__);
266		return -EINVAL;
267	}
268
269	/* save all necessary core registers not covered by the drivers */
270
271	samsung_pm_save_gpios();
272	samsung_pm_saved_gpios();
273	s3c_pm_save_uarts();
274	s3c_pm_save_core();
275
276	/* set the irq configuration for wake */
277
278	s3c_pm_configure_extint();
279
280	S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
281	    s3c_irqwake_intmask, s3c_irqwake_eintmask);
282
283	s3c_pm_arch_prepare_irqs();
284
285	/* call cpu specific preparation */
286
287	pm_cpu_prep();
288
289	/* flush cache back to ram */
290
291	flush_cache_all();
292
293	s3c_pm_check_store();
294
295	/* send the cpu to sleep... */
296
297	s3c_pm_arch_stop_clocks();
298
299	/* this will also act as our return point from when
300	 * we resume as it saves its own register state and restores it
301	 * during the resume.  */
302
303	cpu_suspend(0, pm_cpu_sleep);
304
305	/* restore the system state */
306
307	s3c_pm_restore_core();
308	s3c_pm_restore_uarts();
309	samsung_pm_restore_gpios();
310	s3c_pm_restored_gpios();
311
312	s3c_pm_debug_init();
313
314	/* check what irq (if any) restored the system */
315
316	s3c_pm_arch_show_resume_irqs();
317
318	S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
319
320	/* LEDs should now be 1110 */
321	s3c_pm_debug_smdkled(1 << 1, 0);
322
323	s3c_pm_check_restore();
324
325	/* ok, let's return from sleep */
326
327	S3C_PMDBG("S3C PM Resume (post-restore)\n");
328	return 0;
329}
330
331static int s3c_pm_prepare(void)
332{
333	/* prepare check area if configured */
334
335	s3c_pm_check_prepare();
336	return 0;
337}
338
339static void s3c_pm_finish(void)
340{
341	s3c_pm_check_cleanup();
342}
343
344static const struct platform_suspend_ops s3c_pm_ops = {
345	.enter		= s3c_pm_enter,
346	.prepare	= s3c_pm_prepare,
347	.finish		= s3c_pm_finish,
348	.valid		= suspend_valid_only_mem,
349};
350
351/* s3c_pm_init
352 *
353 * Attach the power management functions. This should be called
354 * from the board specific initialisation if the board supports
355 * it.
356*/
357
358int __init s3c_pm_init(void)
359{
360	printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
361
362	suspend_set_ops(&s3c_pm_ops);
363	return 0;
364}
365