ARM: 5770/1: Add DMA Engine support to at91sam9g45
[deliverable/linux.git] / arch / arm / mach-at91 / pm.c
CommitLineData
907d6deb 1/*
9d041268 2 * arch/arm/mach-at91/pm.c
907d6deb
AV
3 * AT91 Power Management
4 *
5 * Copyright (C) 2005 David Brownell
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
95d9ffbe 13#include <linux/suspend.h>
907d6deb
AV
14#include <linux/sched.h>
15#include <linux/proc_fs.h>
907d6deb
AV
16#include <linux/interrupt.h>
17#include <linux/sysfs.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
fced80c7 20#include <linux/io.h>
907d6deb 21
907d6deb
AV
22#include <asm/irq.h>
23#include <asm/atomic.h>
24#include <asm/mach/time.h>
25#include <asm/mach/irq.h>
907d6deb 26
a09e64fb
RK
27#include <mach/at91_pmc.h>
28#include <mach/gpio.h>
29#include <mach/cpu.h>
907d6deb
AV
30
31#include "generic.h"
32
f5d0f457 33#ifdef CONFIG_ARCH_AT91RM9200
a09e64fb 34#include <mach/at91rm9200_mc.h>
f5d0f457
AV
35
36/*
37 * The AT91RM9200 goes into self-refresh mode with this command, and will
38 * terminate self-refresh automatically on the next SDRAM access.
39 */
40#define sdram_selfrefresh_enable() at91_sys_write(AT91_SDRAMC_SRR, 1)
41#define sdram_selfrefresh_disable() do {} while (0)
42
43#elif defined(CONFIG_ARCH_AT91CAP9)
a09e64fb 44#include <mach/at91cap9_ddrsdr.h>
f5d0f457
AV
45
46static u32 saved_lpr;
47
48static inline void sdram_selfrefresh_enable(void)
49{
50 u32 lpr;
51
52 saved_lpr = at91_sys_read(AT91_DDRSDRC_LPR);
53
54 lpr = saved_lpr & ~AT91_DDRSDRC_LPCB;
55 at91_sys_write(AT91_DDRSDRC_LPR, lpr | AT91_DDRSDRC_LPCB_SELF_REFRESH);
56}
57
58#define sdram_selfrefresh_disable() at91_sys_write(AT91_DDRSDRC_LPR, saved_lpr)
59
60#else
a09e64fb 61#include <mach/at91sam9_sdramc.h>
f5d0f457 62
136eb955
DB
63#ifdef CONFIG_ARCH_AT91SAM9263
64/*
65 * FIXME either or both the SDRAM controllers (EB0, EB1) might be in use;
66 * handle those cases both here and in the Suspend-To-RAM support.
67 */
68#define AT91_SDRAMC AT91_SDRAMC0
69#warning Assuming EB1 SDRAM controller is *NOT* used
70#endif
71
f5d0f457
AV
72static u32 saved_lpr;
73
74static inline void sdram_selfrefresh_enable(void)
75{
76 u32 lpr;
77
78 saved_lpr = at91_sys_read(AT91_SDRAMC_LPR);
79
80 lpr = saved_lpr & ~AT91_SDRAMC_LPCB;
81 at91_sys_write(AT91_SDRAMC_LPR, lpr | AT91_SDRAMC_LPCB_SELF_REFRESH);
82}
83
84#define sdram_selfrefresh_disable() at91_sys_write(AT91_SDRAMC_LPR, saved_lpr)
85
f5d0f457
AV
86#endif
87
907d6deb 88
565ac445
AV
89/*
90 * Show the reason for the previous system reset.
91 */
92#if defined(AT91_SHDWC)
93
a09e64fb
RK
94#include <mach/at91_rstc.h>
95#include <mach/at91_shdwc.h>
565ac445
AV
96
97static void __init show_reset_status(void)
98{
99 static char reset[] __initdata = "reset";
100
101 static char general[] __initdata = "general";
102 static char wakeup[] __initdata = "wakeup";
103 static char watchdog[] __initdata = "watchdog";
104 static char software[] __initdata = "software";
105 static char user[] __initdata = "user";
106 static char unknown[] __initdata = "unknown";
107
108 static char signal[] __initdata = "signal";
109 static char rtc[] __initdata = "rtc";
110 static char rtt[] __initdata = "rtt";
111 static char restore[] __initdata = "power-restored";
112
113 char *reason, *r2 = reset;
114 u32 reset_type, wake_type;
115
116 reset_type = at91_sys_read(AT91_RSTC_SR) & AT91_RSTC_RSTTYP;
117 wake_type = at91_sys_read(AT91_SHDW_SR);
118
119 switch (reset_type) {
120 case AT91_RSTC_RSTTYP_GENERAL:
121 reason = general;
122 break;
123 case AT91_RSTC_RSTTYP_WAKEUP:
124 /* board-specific code enabled the wakeup sources */
125 reason = wakeup;
126
127 /* "wakeup signal" */
128 if (wake_type & AT91_SHDW_WAKEUP0)
129 r2 = signal;
130 else {
131 r2 = reason;
132 if (wake_type & AT91_SHDW_RTTWK) /* rtt wakeup */
133 reason = rtt;
134 else if (wake_type & AT91_SHDW_RTCWK) /* rtc wakeup */
135 reason = rtc;
136 else if (wake_type == 0) /* power-restored wakeup */
137 reason = restore;
138 else /* unknown wakeup */
139 reason = unknown;
140 }
141 break;
142 case AT91_RSTC_RSTTYP_WATCHDOG:
143 reason = watchdog;
144 break;
145 case AT91_RSTC_RSTTYP_SOFTWARE:
146 reason = software;
147 break;
148 case AT91_RSTC_RSTTYP_USER:
149 reason = user;
150 break;
151 default:
152 reason = unknown;
153 break;
154 }
155 pr_info("AT91: Starting after %s %s\n", reason, r2);
156}
157#else
158static void __init show_reset_status(void) {}
159#endif
160
161
907d6deb
AV
162static int at91_pm_valid_state(suspend_state_t state)
163{
164 switch (state) {
165 case PM_SUSPEND_ON:
166 case PM_SUSPEND_STANDBY:
167 case PM_SUSPEND_MEM:
168 return 1;
169
170 default:
171 return 0;
172 }
173}
174
175
176static suspend_state_t target_state;
177
178/*
179 * Called after processes are frozen, but before we shutdown devices.
180 */
c697eece 181static int at91_pm_begin(suspend_state_t state)
907d6deb
AV
182{
183 target_state = state;
184 return 0;
185}
186
187/*
188 * Verify that all the clocks are correct before entering
189 * slow-clock mode.
190 */
191static int at91_pm_verify_clocks(void)
192{
193 unsigned long scsr;
194 int i;
195
196 scsr = at91_sys_read(AT91_PMC_SCSR);
197
198 /* USB must not be using PLLB */
d481f864
AV
199 if (cpu_is_at91rm9200()) {
200 if ((scsr & (AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP)) != 0) {
7f96b1ca 201 pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
d481f864
AV
202 return 0;
203 }
b319ff80
NF
204 } else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() || cpu_is_at91sam9263()
205 || cpu_is_at91sam9g20() || cpu_is_at91sam9g10()) {
b6b27ae5 206 if ((scsr & (AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP)) != 0) {
7f96b1ca 207 pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
b6b27ae5
AV
208 return 0;
209 }
2b3b3516
AV
210 } else if (cpu_is_at91cap9()) {
211 if ((scsr & AT91CAP9_PMC_UHP) != 0) {
7f96b1ca 212 pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
2b3b3516
AV
213 return 0;
214 }
907d6deb
AV
215 }
216
217#ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
218 /* PCK0..PCK3 must be disabled, or configured to use clk32k */
219 for (i = 0; i < 4; i++) {
220 u32 css;
221
222 if ((scsr & (AT91_PMC_PCK0 << i)) == 0)
223 continue;
224
225 css = at91_sys_read(AT91_PMC_PCKR(i)) & AT91_PMC_CSS;
226 if (css != AT91_PMC_CSS_SLOW) {
7f96b1ca 227 pr_err("AT91: PM - Suspend-to-RAM with PCK%d src %d\n", i, css);
907d6deb
AV
228 return 0;
229 }
230 }
231#endif
232
233 return 1;
234}
235
236/*
237 * Call this from platform driver suspend() to see how deeply to suspend.
238 * For example, some controllers (like OHCI) need one of the PLL clocks
239 * in order to act as a wakeup source, and those are not available when
240 * going into slow clock mode.
241 *
242 * REVISIT: generalize as clk_will_be_available(clk)? Other platforms have
243 * the very same problem (but not using at91 main_clk), and it'd be better
244 * to add one generic API rather than lots of platform-specific ones.
245 */
246int at91_suspend_entering_slow_clock(void)
247{
248 return (target_state == PM_SUSPEND_MEM);
249}
250EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
251
252
253static void (*slow_clock)(void);
254
f5d0f457
AV
255#ifdef CONFIG_AT91_SLOW_CLOCK
256extern void at91_slow_clock(void);
257extern u32 at91_slow_clock_sz;
258#endif
259
907d6deb 260
907d6deb
AV
261static int at91_pm_enter(suspend_state_t state)
262{
263 at91_gpio_suspend();
264 at91_irq_suspend();
265
266 pr_debug("AT91: PM - wake mask %08x, pm state %d\n",
267 /* remember all the always-wake irqs */
268 (at91_sys_read(AT91_PMC_PCSR)
269 | (1 << AT91_ID_FIQ)
270 | (1 << AT91_ID_SYS)
1f4fd0a0 271 | (at91_extern_irq))
907d6deb
AV
272 & at91_sys_read(AT91_AIC_IMR),
273 state);
274
275 switch (state) {
276 /*
277 * Suspend-to-RAM is like STANDBY plus slow clock mode, so
278 * drivers must suspend more deeply: only the master clock
279 * controller may be using the main oscillator.
280 */
281 case PM_SUSPEND_MEM:
282 /*
283 * Ensure that clocks are in a valid state.
284 */
285 if (!at91_pm_verify_clocks())
286 goto error;
287
288 /*
289 * Enter slow clock mode by switching over to clk32k and
290 * turning off the main oscillator; reverse on wakeup.
291 */
292 if (slow_clock) {
f5d0f457
AV
293#ifdef CONFIG_AT91_SLOW_CLOCK
294 /* copy slow_clock handler to SRAM, and call it */
295 memcpy(slow_clock, at91_slow_clock, at91_slow_clock_sz);
296#endif
907d6deb
AV
297 slow_clock();
298 break;
299 } else {
f5d0f457 300 pr_info("AT91: PM - no slow clock mode enabled ...\n");
907d6deb
AV
301 /* FALLTHROUGH leaving master clock alone */
302 }
303
304 /*
305 * STANDBY mode has *all* drivers suspended; ignores irqs not
306 * marked as 'wakeup' event sources; and reduces DRAM power.
307 * But otherwise it's identical to PM_SUSPEND_ON: cpu idle, and
308 * nothing fancy done with main or cpu clocks.
309 */
310 case PM_SUSPEND_STANDBY:
311 /*
312 * NOTE: the Wait-for-Interrupt instruction needs to be
f5d0f457
AV
313 * in icache so no SDRAM accesses are needed until the
314 * wakeup IRQ occurs and self-refresh is terminated.
907d6deb
AV
315 */
316 asm("b 1f; .align 5; 1:");
317 asm("mcr p15, 0, r0, c7, c10, 4"); /* drain write buffer */
f5d0f457
AV
318 sdram_selfrefresh_enable();
319 asm("mcr p15, 0, r0, c7, c0, 4"); /* wait for interrupt */
320 sdram_selfrefresh_disable();
321 break;
907d6deb
AV
322
323 case PM_SUSPEND_ON:
324 asm("mcr p15, 0, r0, c7, c0, 4"); /* wait for interrupt */
325 break;
326
327 default:
328 pr_debug("AT91: PM - bogus suspend state %d\n", state);
329 goto error;
330 }
331
332 pr_debug("AT91: PM - wakeup %08x\n",
333 at91_sys_read(AT91_AIC_IPR) & at91_sys_read(AT91_AIC_IMR));
334
335error:
336 target_state = PM_SUSPEND_ON;
337 at91_irq_resume();
338 at91_gpio_resume();
339 return 0;
340}
341
c697eece
RW
342/*
343 * Called right prior to thawing processes.
344 */
345static void at91_pm_end(void)
346{
347 target_state = PM_SUSPEND_ON;
348}
349
907d6deb 350
26398a70 351static struct platform_suspend_ops at91_pm_ops ={
c697eece
RW
352 .valid = at91_pm_valid_state,
353 .begin = at91_pm_begin,
354 .enter = at91_pm_enter,
355 .end = at91_pm_end,
907d6deb
AV
356};
357
358static int __init at91_pm_init(void)
359{
f5d0f457
AV
360#ifdef CONFIG_AT91_SLOW_CLOCK
361 slow_clock = (void *) (AT91_IO_VIRT_BASE - at91_slow_clock_sz);
907d6deb
AV
362#endif
363
f5d0f457
AV
364 pr_info("AT91: Power Management%s\n", (slow_clock ? " (with slow clock mode)" : ""));
365
366#ifdef CONFIG_ARCH_AT91RM9200
367 /* AT91RM9200 SDRAM low-power mode cannot be used with self-refresh. */
907d6deb 368 at91_sys_write(AT91_SDRAMC_LPR, 0);
f5d0f457 369#endif
907d6deb 370
26398a70 371 suspend_set_ops(&at91_pm_ops);
907d6deb 372
565ac445 373 show_reset_status();
907d6deb
AV
374 return 0;
375}
376arch_initcall(at91_pm_init);
This page took 0.455591 seconds and 5 git commands to generate.