Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[deliverable/linux.git] / arch / arm / mach-omap2 / cpuidle34xx.c
1 /*
2 * linux/arch/arm/mach-omap2/cpuidle34xx.c
3 *
4 * OMAP3 CPU IDLE Routines
5 *
6 * Copyright (C) 2008 Texas Instruments, Inc.
7 * Rajendra Nayak <rnayak@ti.com>
8 *
9 * Copyright (C) 2007 Texas Instruments, Inc.
10 * Karthik Dasu <karthik-dp@ti.com>
11 *
12 * Copyright (C) 2006 Nokia Corporation
13 * Tony Lindgren <tony@atomide.com>
14 *
15 * Copyright (C) 2005 Texas Instruments, Inc.
16 * Richard Woodruff <r-woodruff2@ti.com>
17 *
18 * Based on pm.c for omap2
19 *
20 * This program is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License version 2 as
22 * published by the Free Software Foundation.
23 */
24
25 #include <linux/sched.h>
26 #include <linux/cpuidle.h>
27 #include <linux/export.h>
28 #include <linux/cpu_pm.h>
29
30 #include "powerdomain.h"
31 #include "clockdomain.h"
32
33 #include "pm.h"
34 #include "control.h"
35 #include "common.h"
36
37 /* Mach specific information to be recorded in the C-state driver_data */
38 struct omap3_idle_statedata {
39 u8 mpu_state;
40 u8 core_state;
41 u8 per_min_state;
42 u8 flags;
43 };
44
45 static struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
46
47 /*
48 * Possible flag bits for struct omap3_idle_statedata.flags:
49 *
50 * OMAP_CPUIDLE_CX_NO_CLKDM_IDLE: don't allow the MPU clockdomain to go
51 * inactive. This in turn prevents the MPU DPLL from entering autoidle
52 * mode, so wakeup latency is greatly reduced, at the cost of additional
53 * energy consumption. This also prevents the CORE clockdomain from
54 * entering idle.
55 */
56 #define OMAP_CPUIDLE_CX_NO_CLKDM_IDLE BIT(0)
57
58 /*
59 * Prevent PER OFF if CORE is not in RETention or OFF as this would
60 * disable PER wakeups completely.
61 */
62 static struct omap3_idle_statedata omap3_idle_data[] = {
63 {
64 .mpu_state = PWRDM_POWER_ON,
65 .core_state = PWRDM_POWER_ON,
66 /* In C1 do not allow PER state lower than CORE state */
67 .per_min_state = PWRDM_POWER_ON,
68 .flags = OMAP_CPUIDLE_CX_NO_CLKDM_IDLE,
69 },
70 {
71 .mpu_state = PWRDM_POWER_ON,
72 .core_state = PWRDM_POWER_ON,
73 .per_min_state = PWRDM_POWER_RET,
74 },
75 {
76 .mpu_state = PWRDM_POWER_RET,
77 .core_state = PWRDM_POWER_ON,
78 .per_min_state = PWRDM_POWER_RET,
79 },
80 {
81 .mpu_state = PWRDM_POWER_OFF,
82 .core_state = PWRDM_POWER_ON,
83 .per_min_state = PWRDM_POWER_RET,
84 },
85 {
86 .mpu_state = PWRDM_POWER_RET,
87 .core_state = PWRDM_POWER_RET,
88 .per_min_state = PWRDM_POWER_OFF,
89 },
90 {
91 .mpu_state = PWRDM_POWER_OFF,
92 .core_state = PWRDM_POWER_RET,
93 .per_min_state = PWRDM_POWER_OFF,
94 },
95 {
96 .mpu_state = PWRDM_POWER_OFF,
97 .core_state = PWRDM_POWER_OFF,
98 .per_min_state = PWRDM_POWER_OFF,
99 },
100 };
101
102 /* Private functions */
103
104 static int __omap3_enter_idle(struct cpuidle_device *dev,
105 struct cpuidle_driver *drv,
106 int index)
107 {
108 struct omap3_idle_statedata *cx = &omap3_idle_data[index];
109
110 local_fiq_disable();
111
112 if (omap_irq_pending() || need_resched())
113 goto return_sleep_time;
114
115 /* Deny idle for C1 */
116 if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE) {
117 clkdm_deny_idle(mpu_pd->pwrdm_clkdms[0]);
118 } else {
119 pwrdm_set_next_pwrst(mpu_pd, cx->mpu_state);
120 pwrdm_set_next_pwrst(core_pd, cx->core_state);
121 }
122
123 /*
124 * Call idle CPU PM enter notifier chain so that
125 * VFP context is saved.
126 */
127 if (cx->mpu_state == PWRDM_POWER_OFF)
128 cpu_pm_enter();
129
130 /* Execute ARM wfi */
131 omap_sram_idle();
132
133 /*
134 * Call idle CPU PM enter notifier chain to restore
135 * VFP context.
136 */
137 if (cx->mpu_state == PWRDM_POWER_OFF &&
138 pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF)
139 cpu_pm_exit();
140
141 /* Re-allow idle for C1 */
142 if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE)
143 clkdm_allow_idle(mpu_pd->pwrdm_clkdms[0]);
144
145 return_sleep_time:
146 local_fiq_enable();
147
148 return index;
149 }
150
151 /**
152 * omap3_enter_idle - Programs OMAP3 to enter the specified state
153 * @dev: cpuidle device
154 * @drv: cpuidle driver
155 * @index: the index of state to be entered
156 *
157 * Called from the CPUidle framework to program the device to the
158 * specified target state selected by the governor.
159 */
160 static inline int omap3_enter_idle(struct cpuidle_device *dev,
161 struct cpuidle_driver *drv,
162 int index)
163 {
164 return cpuidle_wrap_enter(dev, drv, index, __omap3_enter_idle);
165 }
166
167 /**
168 * next_valid_state - Find next valid C-state
169 * @dev: cpuidle device
170 * @drv: cpuidle driver
171 * @index: Index of currently selected c-state
172 *
173 * If the state corresponding to index is valid, index is returned back
174 * to the caller. Else, this function searches for a lower c-state which is
175 * still valid (as defined in omap3_power_states[]) and returns its index.
176 *
177 * A state is valid if the 'valid' field is enabled and
178 * if it satisfies the enable_off_mode condition.
179 */
180 static int next_valid_state(struct cpuidle_device *dev,
181 struct cpuidle_driver *drv, int index)
182 {
183 struct omap3_idle_statedata *cx = &omap3_idle_data[index];
184 u32 mpu_deepest_state = PWRDM_POWER_RET;
185 u32 core_deepest_state = PWRDM_POWER_RET;
186 int idx;
187 int next_index = 0; /* C1 is the default value */
188
189 if (enable_off_mode) {
190 mpu_deepest_state = PWRDM_POWER_OFF;
191 /*
192 * Erratum i583: valable for ES rev < Es1.2 on 3630.
193 * CORE OFF mode is not supported in a stable form, restrict
194 * instead the CORE state to RET.
195 */
196 if (!IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583))
197 core_deepest_state = PWRDM_POWER_OFF;
198 }
199
200 /* Check if current state is valid */
201 if ((cx->mpu_state >= mpu_deepest_state) &&
202 (cx->core_state >= core_deepest_state))
203 return index;
204
205 /*
206 * Drop to next valid state.
207 * Start search from the next (lower) state.
208 */
209 for (idx = index - 1; idx >= 0; idx--) {
210 cx = &omap3_idle_data[idx];
211 if ((cx->mpu_state >= mpu_deepest_state) &&
212 (cx->core_state >= core_deepest_state)) {
213 next_index = idx;
214 break;
215 }
216 }
217
218 return next_index;
219 }
220
221 /**
222 * omap3_enter_idle_bm - Checks for any bus activity
223 * @dev: cpuidle device
224 * @drv: cpuidle driver
225 * @index: array index of target state to be programmed
226 *
227 * This function checks for any pending activity and then programs
228 * the device to the specified or a safer state.
229 */
230 static int omap3_enter_idle_bm(struct cpuidle_device *dev,
231 struct cpuidle_driver *drv,
232 int index)
233 {
234 int new_state_idx, ret;
235 u8 per_next_state, per_saved_state;
236 struct omap3_idle_statedata *cx;
237
238 /*
239 * Use only C1 if CAM is active.
240 * CAM does not have wakeup capability in OMAP3.
241 */
242 if (pwrdm_read_pwrst(cam_pd) == PWRDM_POWER_ON)
243 new_state_idx = drv->safe_state_index;
244 else
245 new_state_idx = next_valid_state(dev, drv, index);
246
247 /*
248 * FIXME: we currently manage device-specific idle states
249 * for PER and CORE in combination with CPU-specific
250 * idle states. This is wrong, and device-specific
251 * idle management needs to be separated out into
252 * its own code.
253 */
254
255 /* Program PER state */
256 cx = &omap3_idle_data[new_state_idx];
257
258 per_next_state = pwrdm_read_next_pwrst(per_pd);
259 per_saved_state = per_next_state;
260 if (per_next_state < cx->per_min_state) {
261 per_next_state = cx->per_min_state;
262 pwrdm_set_next_pwrst(per_pd, per_next_state);
263 }
264
265 ret = omap3_enter_idle(dev, drv, new_state_idx);
266
267 /* Restore original PER state if it was modified */
268 if (per_next_state != per_saved_state)
269 pwrdm_set_next_pwrst(per_pd, per_saved_state);
270
271 return ret;
272 }
273
274 static DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
275
276 static struct cpuidle_driver omap3_idle_driver = {
277 .name = "omap3_idle",
278 .owner = THIS_MODULE,
279 .states = {
280 {
281 .enter = omap3_enter_idle_bm,
282 .exit_latency = 2 + 2,
283 .target_residency = 5,
284 .flags = CPUIDLE_FLAG_TIME_VALID,
285 .name = "C1",
286 .desc = "MPU ON + CORE ON",
287 },
288 {
289 .enter = omap3_enter_idle_bm,
290 .exit_latency = 10 + 10,
291 .target_residency = 30,
292 .flags = CPUIDLE_FLAG_TIME_VALID,
293 .name = "C2",
294 .desc = "MPU ON + CORE ON",
295 },
296 {
297 .enter = omap3_enter_idle_bm,
298 .exit_latency = 50 + 50,
299 .target_residency = 300,
300 .flags = CPUIDLE_FLAG_TIME_VALID,
301 .name = "C3",
302 .desc = "MPU RET + CORE ON",
303 },
304 {
305 .enter = omap3_enter_idle_bm,
306 .exit_latency = 1500 + 1800,
307 .target_residency = 4000,
308 .flags = CPUIDLE_FLAG_TIME_VALID,
309 .name = "C4",
310 .desc = "MPU OFF + CORE ON",
311 },
312 {
313 .enter = omap3_enter_idle_bm,
314 .exit_latency = 2500 + 7500,
315 .target_residency = 12000,
316 .flags = CPUIDLE_FLAG_TIME_VALID,
317 .name = "C5",
318 .desc = "MPU RET + CORE RET",
319 },
320 {
321 .enter = omap3_enter_idle_bm,
322 .exit_latency = 3000 + 8500,
323 .target_residency = 15000,
324 .flags = CPUIDLE_FLAG_TIME_VALID,
325 .name = "C6",
326 .desc = "MPU OFF + CORE RET",
327 },
328 {
329 .enter = omap3_enter_idle_bm,
330 .exit_latency = 10000 + 30000,
331 .target_residency = 30000,
332 .flags = CPUIDLE_FLAG_TIME_VALID,
333 .name = "C7",
334 .desc = "MPU OFF + CORE OFF",
335 },
336 },
337 .state_count = ARRAY_SIZE(omap3_idle_data),
338 .safe_state_index = 0,
339 };
340
341 /* Public functions */
342
343 /**
344 * omap3_idle_init - Init routine for OMAP3 idle
345 *
346 * Registers the OMAP3 specific cpuidle driver to the cpuidle
347 * framework with the valid set of states.
348 */
349 int __init omap3_idle_init(void)
350 {
351 struct cpuidle_device *dev;
352
353 mpu_pd = pwrdm_lookup("mpu_pwrdm");
354 core_pd = pwrdm_lookup("core_pwrdm");
355 per_pd = pwrdm_lookup("per_pwrdm");
356 cam_pd = pwrdm_lookup("cam_pwrdm");
357
358 if (!mpu_pd || !core_pd || !per_pd || !cam_pd)
359 return -ENODEV;
360
361 cpuidle_register_driver(&omap3_idle_driver);
362
363 dev = &per_cpu(omap3_idle_dev, smp_processor_id());
364 dev->cpu = 0;
365
366 if (cpuidle_register_device(dev)) {
367 printk(KERN_ERR "%s: CPUidle register device failed\n",
368 __func__);
369 return -EIO;
370 }
371
372 return 0;
373 }
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