Root/arch/arm/plat-samsung/pm.c

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 <mach/hardware.h>
24#include <mach/map.h>
25
26#include <plat/regs-serial.h>
27#include <mach/regs-clock.h>
28#include <mach/regs-irq.h>
29#include <asm/irq.h>
30
31#include <plat/pm.h>
32#include <mach/pm-core.h>
33
34/* for external use */
35
36unsigned long s3c_pm_flags;
37
38/* Debug code:
39 *
40 * This code supports debug output to the low level UARTs for use on
41 * resume before the console layer is available.
42*/
43
44#ifdef CONFIG_SAMSUNG_PM_DEBUG
45extern void printascii(const char *);
46
47void s3c_pm_dbg(const char *fmt, ...)
48{
49    va_list va;
50    char buff[256];
51
52    va_start(va, fmt);
53    vsprintf(buff, fmt, va);
54    va_end(va);
55
56    printascii(buff);
57}
58
59static inline void s3c_pm_debug_init(void)
60{
61    /* restart uart clocks so we can use them to output */
62    s3c_pm_debug_init_uart();
63}
64
65#else
66#define s3c_pm_debug_init() do { } while(0)
67
68#endif /* CONFIG_SAMSUNG_PM_DEBUG */
69
70/* Save the UART configurations if we are configured for debug. */
71
72unsigned char pm_uart_udivslot;
73
74#ifdef CONFIG_SAMSUNG_PM_DEBUG
75
76struct pm_uart_save uart_save[CONFIG_SERIAL_SAMSUNG_UARTS];
77
78static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
79{
80    void __iomem *regs = S3C_VA_UARTx(uart);
81
82    save->ulcon = __raw_readl(regs + S3C2410_ULCON);
83    save->ucon = __raw_readl(regs + S3C2410_UCON);
84    save->ufcon = __raw_readl(regs + S3C2410_UFCON);
85    save->umcon = __raw_readl(regs + S3C2410_UMCON);
86    save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
87
88    if (pm_uart_udivslot)
89        save->udivslot = __raw_readl(regs + S3C2443_DIVSLOT);
90
91    S3C_PMDBG("UART[%d]: ULCON=%04x, UCON=%04x, UFCON=%04x, UBRDIV=%04x\n",
92          uart, save->ulcon, save->ucon, save->ufcon, save->ubrdiv);
93}
94
95static void s3c_pm_save_uarts(void)
96{
97    struct pm_uart_save *save = uart_save;
98    unsigned int uart;
99
100    for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
101        s3c_pm_save_uart(uart, save);
102}
103
104static void s3c_pm_restore_uart(unsigned int uart, struct pm_uart_save *save)
105{
106    void __iomem *regs = S3C_VA_UARTx(uart);
107
108    s3c_pm_arch_update_uart(regs, save);
109
110    __raw_writel(save->ulcon, regs + S3C2410_ULCON);
111    __raw_writel(save->ucon, regs + S3C2410_UCON);
112    __raw_writel(save->ufcon, regs + S3C2410_UFCON);
113    __raw_writel(save->umcon, regs + S3C2410_UMCON);
114    __raw_writel(save->ubrdiv, regs + S3C2410_UBRDIV);
115
116    if (pm_uart_udivslot)
117        __raw_writel(save->udivslot, regs + S3C2443_DIVSLOT);
118}
119
120static void s3c_pm_restore_uarts(void)
121{
122    struct pm_uart_save *save = uart_save;
123    unsigned int uart;
124
125    for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
126        s3c_pm_restore_uart(uart, save);
127}
128#else
129static void s3c_pm_save_uarts(void) { }
130static void s3c_pm_restore_uarts(void) { }
131#endif
132
133/* The IRQ ext-int code goes here, it is too small to currently bother
134 * with its own file. */
135
136unsigned long s3c_irqwake_intmask = 0xffffffffL;
137unsigned long s3c_irqwake_eintmask = 0xffffffffL;
138
139int s3c_irqext_wake(unsigned int irqno, unsigned int state)
140{
141    unsigned long bit = 1L << IRQ_EINT_BIT(irqno);
142
143    if (!(s3c_irqwake_eintallow & bit))
144        return -ENOENT;
145
146    printk(KERN_INFO "wake %s for irq %d\n",
147           state ? "enabled" : "disabled", irqno);
148
149    if (!state)
150        s3c_irqwake_eintmask |= bit;
151    else
152        s3c_irqwake_eintmask &= ~bit;
153
154    return 0;
155}
156
157/* helper functions to save and restore register state */
158
159/**
160 * s3c_pm_do_save() - save a set of registers for restoration on resume.
161 * @ptr: Pointer to an array of registers.
162 * @count: Size of the ptr array.
163 *
164 * Run through the list of registers given, saving their contents in the
165 * array for later restoration when we wakeup.
166 */
167void s3c_pm_do_save(struct sleep_save *ptr, int count)
168{
169    for (; count > 0; count--, ptr++) {
170        ptr->val = __raw_readl(ptr->reg);
171        S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
172    }
173}
174
175/**
176 * s3c_pm_do_restore() - restore register values from the save list.
177 * @ptr: Pointer to an array of registers.
178 * @count: Size of the ptr array.
179 *
180 * Restore the register values saved from s3c_pm_do_save().
181 *
182 * Note, we do not use S3C_PMDBG() in here, as the system may not have
183 * restore the UARTs state yet
184*/
185
186void s3c_pm_do_restore(struct sleep_save *ptr, int count)
187{
188    for (; count > 0; count--, ptr++) {
189        printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
190               ptr->reg, ptr->val, __raw_readl(ptr->reg));
191
192        __raw_writel(ptr->val, ptr->reg);
193    }
194}
195
196/**
197 * s3c_pm_do_restore_core() - early restore register values from save list.
198 *
199 * This is similar to s3c_pm_do_restore() except we try and minimise the
200 * side effects of the function in case registers that hardware might need
201 * to work has been restored.
202 *
203 * WARNING: Do not put any debug in here that may effect memory or use
204 * peripherals, as things may be changing!
205*/
206
207void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
208{
209    for (; count > 0; count--, ptr++)
210        __raw_writel(ptr->val, ptr->reg);
211}
212
213/* s3c2410_pm_show_resume_irqs
214 *
215 * print any IRQs asserted at resume time (ie, we woke from)
216*/
217static void s3c_pm_show_resume_irqs(int start, unsigned long which,
218                    unsigned long mask)
219{
220    int i;
221
222    which &= ~mask;
223
224    for (i = 0; i <= 31; i++) {
225        if (which & (1L<<i)) {
226            S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
227        }
228    }
229}
230
231
232void (*pm_cpu_prep)(void);
233void (*pm_cpu_sleep)(void);
234
235#define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
236
237/* s3c_pm_enter
238 *
239 * central control for sleep/resume process
240*/
241
242static int s3c_pm_enter(suspend_state_t state)
243{
244    static unsigned long regs_save[16];
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    /* store the physical address of the register recovery block */
270
271    s3c_sleep_save_phys = virt_to_phys(regs_save);
272
273    S3C_PMDBG("s3c_sleep_save_phys=0x%08lx\n", s3c_sleep_save_phys);
274
275    /* save all necessary core registers not covered by the drivers */
276
277    s3c_pm_save_gpios();
278    s3c_pm_save_uarts();
279    s3c_pm_save_core();
280
281    /* set the irq configuration for wake */
282
283    s3c_pm_configure_extint();
284
285    S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
286        s3c_irqwake_intmask, s3c_irqwake_eintmask);
287
288    s3c_pm_arch_prepare_irqs();
289
290    /* call cpu specific preparation */
291
292    pm_cpu_prep();
293
294    /* flush cache back to ram */
295
296    flush_cache_all();
297
298    s3c_pm_check_store();
299
300    /* send the cpu to sleep... */
301
302    s3c_pm_arch_stop_clocks();
303
304    /* s3c_cpu_save will also act as our return point from when
305     * we resume as it saves its own register state and restores it
306     * during the resume. */
307
308    s3c_cpu_save(regs_save);
309
310    /* restore the cpu state using the kernel's cpu init code. */
311
312    cpu_init();
313
314    /* restore the system state */
315
316    s3c_pm_restore_core();
317    s3c_pm_restore_uarts();
318    s3c_pm_restore_gpios();
319
320    s3c_pm_debug_init();
321
322    /* check what irq (if any) restored the system */
323
324    s3c_pm_arch_show_resume_irqs();
325
326    S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
327
328    /* LEDs should now be 1110 */
329    s3c_pm_debug_smdkled(1 << 1, 0);
330
331    s3c_pm_check_restore();
332
333    /* ok, let's return from sleep */
334
335    S3C_PMDBG("S3C PM Resume (post-restore)\n");
336    return 0;
337}
338
339/* callback from assembly code */
340void s3c_pm_cb_flushcache(void)
341{
342    flush_cache_all();
343}
344
345static int s3c_pm_prepare(void)
346{
347    /* prepare check area if configured */
348
349    s3c_pm_check_prepare();
350    return 0;
351}
352
353static void s3c_pm_finish(void)
354{
355    s3c_pm_check_cleanup();
356}
357
358static struct platform_suspend_ops s3c_pm_ops = {
359    .enter = s3c_pm_enter,
360    .prepare = s3c_pm_prepare,
361    .finish = s3c_pm_finish,
362    .valid = suspend_valid_only_mem,
363};
364
365/* s3c_pm_init
366 *
367 * Attach the power management functions. This should be called
368 * from the board specific initialisation if the board supports
369 * it.
370*/
371
372int __init s3c_pm_init(void)
373{
374    printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
375
376    suspend_set_ops(&s3c_pm_ops);
377    return 0;
378}
379

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