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authorAndrew Victor <andrew@sanpeople.com>2007-02-05 05:42:07 -0500
committerRussell King <rmk+kernel@arm.linux.org.uk>2007-02-08 09:50:56 -0500
commit9d0412680e6c7b685ee466842047bcfb924d6dc5 (patch)
treec79300964ef1aca5d24571696f95e76b37c14679 /arch/arm/mach-at91/pm.c
parenta93d48cc6019f84394b31d10c0d830a3b71696be (diff)
[ARM] 4124/1: Rename mach-at91rm9200 and arch-at91rm9200 directories
Now that Linux includes support for the Atmel AT91SAM9260 and AT91SAM9261 processors in addition to the original Atmel AT91RM9200 (with support for more AT91 processors pending), the "mach-at91rm9200" and "arch-at91rm9200" directories should be renamed to indicate their more generic nature. The following git commands should be run BEFORE applying this patch: git-mv arch/arm/mach-at91rm9200 arch/arm/mach-at91 git-mv include/asm-arm/arch-at91rm9200 include/asm-arm/arch-at91 Signed-off-by: Andrew Victor <andrew@sanpeople.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-at91/pm.c')
-rw-r--r--arch/arm/mach-at91/pm.c227
1 files changed, 227 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
new file mode 100644
index 000000000000..e095b1fe8d8a
--- /dev/null
+++ b/arch/arm/mach-at91/pm.c
@@ -0,0 +1,227 @@
1/*
2 * arch/arm/mach-at91/pm.c
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
13#include <linux/pm.h>
14#include <linux/sched.h>
15#include <linux/proc_fs.h>
16#include <linux/pm.h>
17#include <linux/interrupt.h>
18#include <linux/sysfs.h>
19#include <linux/module.h>
20#include <linux/platform_device.h>
21
22#include <asm/io.h>
23#include <asm/irq.h>
24#include <asm/atomic.h>
25#include <asm/mach/time.h>
26#include <asm/mach/irq.h>
27#include <asm/mach-types.h>
28
29#include <asm/arch/at91_pmc.h>
30#include <asm/arch/at91rm9200_mc.h>
31#include <asm/arch/gpio.h>
32#include <asm/arch/cpu.h>
33
34#include "generic.h"
35
36
37static int at91_pm_valid_state(suspend_state_t state)
38{
39 switch (state) {
40 case PM_SUSPEND_ON:
41 case PM_SUSPEND_STANDBY:
42 case PM_SUSPEND_MEM:
43 return 1;
44
45 default:
46 return 0;
47 }
48}
49
50
51static suspend_state_t target_state;
52
53/*
54 * Called after processes are frozen, but before we shutdown devices.
55 */
56static int at91_pm_prepare(suspend_state_t state)
57{
58 target_state = state;
59 return 0;
60}
61
62/*
63 * Verify that all the clocks are correct before entering
64 * slow-clock mode.
65 */
66static int at91_pm_verify_clocks(void)
67{
68 unsigned long scsr;
69 int i;
70
71 scsr = at91_sys_read(AT91_PMC_SCSR);
72
73 /* USB must not be using PLLB */
74 if (cpu_is_at91rm9200()) {
75 if ((scsr & (AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP)) != 0) {
76 pr_debug("AT91: PM - Suspend-to-RAM with USB still active\n");
77 return 0;
78 }
79 } else if (cpu_is_at91sam9260()) {
80#warning "Check SAM9260 USB clocks"
81 } else if (cpu_is_at91sam9261()) {
82#warning "Check SAM9261 USB clocks"
83 }
84
85#ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
86 /* PCK0..PCK3 must be disabled, or configured to use clk32k */
87 for (i = 0; i < 4; i++) {
88 u32 css;
89
90 if ((scsr & (AT91_PMC_PCK0 << i)) == 0)
91 continue;
92
93 css = at91_sys_read(AT91_PMC_PCKR(i)) & AT91_PMC_CSS;
94 if (css != AT91_PMC_CSS_SLOW) {
95 pr_debug("AT91: PM - Suspend-to-RAM with PCK%d src %d\n", i, css);
96 return 0;
97 }
98 }
99#endif
100
101 return 1;
102}
103
104/*
105 * Call this from platform driver suspend() to see how deeply to suspend.
106 * For example, some controllers (like OHCI) need one of the PLL clocks
107 * in order to act as a wakeup source, and those are not available when
108 * going into slow clock mode.
109 *
110 * REVISIT: generalize as clk_will_be_available(clk)? Other platforms have
111 * the very same problem (but not using at91 main_clk), and it'd be better
112 * to add one generic API rather than lots of platform-specific ones.
113 */
114int at91_suspend_entering_slow_clock(void)
115{
116 return (target_state == PM_SUSPEND_MEM);
117}
118EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
119
120
121static void (*slow_clock)(void);
122
123
124static int at91_pm_enter(suspend_state_t state)
125{
126 at91_gpio_suspend();
127 at91_irq_suspend();
128
129 pr_debug("AT91: PM - wake mask %08x, pm state %d\n",
130 /* remember all the always-wake irqs */
131 (at91_sys_read(AT91_PMC_PCSR)
132 | (1 << AT91_ID_FIQ)
133 | (1 << AT91_ID_SYS)
134 | (at91_extern_irq))
135 & at91_sys_read(AT91_AIC_IMR),
136 state);
137
138 switch (state) {
139 /*
140 * Suspend-to-RAM is like STANDBY plus slow clock mode, so
141 * drivers must suspend more deeply: only the master clock
142 * controller may be using the main oscillator.
143 */
144 case PM_SUSPEND_MEM:
145 /*
146 * Ensure that clocks are in a valid state.
147 */
148 if (!at91_pm_verify_clocks())
149 goto error;
150
151 /*
152 * Enter slow clock mode by switching over to clk32k and
153 * turning off the main oscillator; reverse on wakeup.
154 */
155 if (slow_clock) {
156 slow_clock();
157 break;
158 } else {
159 /* DEVELOPMENT ONLY */
160 pr_info("AT91: PM - no slow clock mode yet ...\n");
161 /* FALLTHROUGH leaving master clock alone */
162 }
163
164 /*
165 * STANDBY mode has *all* drivers suspended; ignores irqs not
166 * marked as 'wakeup' event sources; and reduces DRAM power.
167 * But otherwise it's identical to PM_SUSPEND_ON: cpu idle, and
168 * nothing fancy done with main or cpu clocks.
169 */
170 case PM_SUSPEND_STANDBY:
171 /*
172 * NOTE: the Wait-for-Interrupt instruction needs to be
173 * in icache so the SDRAM stays in self-refresh mode until
174 * the wakeup IRQ occurs.
175 */
176 asm("b 1f; .align 5; 1:");
177 asm("mcr p15, 0, r0, c7, c10, 4"); /* drain write buffer */
178 at91_sys_write(AT91_SDRAMC_SRR, 1); /* self-refresh mode */
179 /* fall though to next state */
180
181 case PM_SUSPEND_ON:
182 asm("mcr p15, 0, r0, c7, c0, 4"); /* wait for interrupt */
183 break;
184
185 default:
186 pr_debug("AT91: PM - bogus suspend state %d\n", state);
187 goto error;
188 }
189
190 pr_debug("AT91: PM - wakeup %08x\n",
191 at91_sys_read(AT91_AIC_IPR) & at91_sys_read(AT91_AIC_IMR));
192
193error:
194 target_state = PM_SUSPEND_ON;
195 at91_irq_resume();
196 at91_gpio_resume();
197 return 0;
198}
199
200
201static struct pm_ops at91_pm_ops ={
202 .pm_disk_mode = 0,
203 .valid = at91_pm_valid_state,
204 .prepare = at91_pm_prepare,
205 .enter = at91_pm_enter,
206};
207
208static int __init at91_pm_init(void)
209{
210 printk("AT91: Power Management\n");
211
212#ifdef CONFIG_AT91_PM_SLOW_CLOCK
213 /* REVISIT allocations of SRAM should be dynamically managed.
214 * FIQ handlers and other components will want SRAM/TCM too...
215 */
216 slow_clock = (void *) (AT91_VA_BASE_SRAM + (3 * SZ_4K));
217 memcpy(slow_clock, at91rm9200_slow_clock, at91rm9200_slow_clock_sz);
218#endif
219
220 /* Disable SDRAM low-power mode. Cannot be used with self-refresh. */
221 at91_sys_write(AT91_SDRAMC_LPR, 0);
222
223 pm_set_ops(&at91_pm_ops);
224
225 return 0;
226}
227arch_initcall(at91_pm_init);