OMAP3: cpuidle: code rework for improved readability
[deliverable/linux.git] / arch / arm / mach-omap2 / cpuidle34xx.c
CommitLineData
99e6a4d2
RN
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
cf22854c 25#include <linux/sched.h>
99e6a4d2
RN
26#include <linux/cpuidle.h>
27
28#include <plat/prcm.h>
20b01669 29#include <plat/irqs.h>
72e06d08 30#include "powerdomain.h"
1540f214 31#include "clockdomain.h"
0f724ed9 32#include <plat/serial.h>
99e6a4d2 33
c98e2230 34#include "pm.h"
4814ced5 35#include "control.h"
c98e2230 36
99e6a4d2
RN
37#ifdef CONFIG_CPU_IDLE
38
bb4de3df
KH
39/*
40 * The latencies/thresholds for various C states have
41 * to be configured from the respective board files.
42 * These are some default values (which might not provide
43 * the best power savings) used on boards which do not
44 * pass these details from the board file.
45 */
46static struct cpuidle_params cpuidle_params_table[] = {
47 /* C1 */
866ba0ef 48 {2 + 2, 5, 1},
bb4de3df 49 /* C2 */
866ba0ef 50 {10 + 10, 30, 1},
bb4de3df 51 /* C3 */
866ba0ef 52 {50 + 50, 300, 1},
bb4de3df 53 /* C4 */
866ba0ef 54 {1500 + 1800, 4000, 1},
bb4de3df 55 /* C5 */
866ba0ef 56 {2500 + 7500, 12000, 1},
bb4de3df 57 /* C6 */
866ba0ef 58 {3000 + 8500, 15000, 1},
bb4de3df 59 /* C7 */
866ba0ef 60 {10000 + 30000, 300000, 1},
bb4de3df 61};
badc303a
JP
62#define OMAP3_NUM_STATES ARRAY_SIZE(cpuidle_params_table)
63
64/* Mach specific information to be recorded in the C-state driver_data */
65struct omap3_idle_statedata {
66 u32 mpu_state;
67 u32 core_state;
68 u8 valid;
69};
70struct omap3_idle_statedata omap3_idle_data[OMAP3_NUM_STATES];
71
72struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
bb4de3df 73
06d8f065
PDS
74static int _cpuidle_allow_idle(struct powerdomain *pwrdm,
75 struct clockdomain *clkdm)
76{
5cd1937b 77 clkdm_allow_idle(clkdm);
06d8f065
PDS
78 return 0;
79}
80
81static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
82 struct clockdomain *clkdm)
83{
5cd1937b 84 clkdm_deny_idle(clkdm);
06d8f065
PDS
85 return 0;
86}
87
99e6a4d2
RN
88/**
89 * omap3_enter_idle - Programs OMAP3 to enter the specified state
90 * @dev: cpuidle device
91 * @state: The target state to be programmed
92 *
93 * Called from the CPUidle framework to program the device to the
94 * specified target state selected by the governor.
95 */
96static int omap3_enter_idle(struct cpuidle_device *dev,
97 struct cpuidle_state *state)
98{
badc303a 99 struct omap3_idle_statedata *cx = cpuidle_get_statedata(state);
99e6a4d2 100 struct timespec ts_preidle, ts_postidle, ts_idle;
c98e2230 101 u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
99e6a4d2 102
99e6a4d2
RN
103 /* Used to keep track of the total time in idle */
104 getnstimeofday(&ts_preidle);
105
106 local_irq_disable();
107 local_fiq_disable();
108
7139178e
JH
109 pwrdm_set_next_pwrst(mpu_pd, mpu_state);
110 pwrdm_set_next_pwrst(core_pd, core_state);
20b01669 111
cf22854c 112 if (omap_irq_pending() || need_resched())
20b01669 113 goto return_sleep_time;
99e6a4d2 114
badc303a
JP
115 /* Deny idle for C1 */
116 if (state == &dev->states[0]) {
06d8f065
PDS
117 pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
118 pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
119 }
120
99e6a4d2
RN
121 /* Execute ARM wfi */
122 omap_sram_idle();
123
badc303a
JP
124 /* Re-allow idle for C1 */
125 if (state == &dev->states[0]) {
06d8f065
PDS
126 pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
127 pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
128 }
129
20b01669 130return_sleep_time:
99e6a4d2
RN
131 getnstimeofday(&ts_postidle);
132 ts_idle = timespec_sub(ts_postidle, ts_preidle);
133
134 local_irq_enable();
135 local_fiq_enable();
136
afbcf619 137 return ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * USEC_PER_SEC;
99e6a4d2
RN
138}
139
6af83b38
SP
140/**
141 * next_valid_state - Find next valid c-state
142 * @dev: cpuidle device
143 * @state: Currently selected c-state
144 *
145 * If the current state is valid, it is returned back to the caller.
146 * Else, this function searches for a lower c-state which is still
badc303a 147 * valid.
6af83b38
SP
148 */
149static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
badc303a 150 struct cpuidle_state *curr)
6af83b38
SP
151{
152 struct cpuidle_state *next = NULL;
c6cd91de 153 struct omap3_idle_statedata *cx = cpuidle_get_statedata(curr);
6af83b38
SP
154
155 /* Check if current state is valid */
156 if (cx->valid) {
157 return curr;
158 } else {
badc303a 159 int idx = OMAP3_NUM_STATES - 1;
6af83b38 160
c6cd91de 161 /* Reach the current state starting at highest C-state */
badc303a 162 for (; idx >= 0; idx--) {
6af83b38
SP
163 if (&dev->states[idx] == curr) {
164 next = &dev->states[idx];
165 break;
166 }
167 }
168
c6cd91de 169 /* Should never hit this condition */
6af83b38
SP
170 WARN_ON(next == NULL);
171
172 /*
173 * Drop to next valid state.
174 * Start search from the next (lower) state.
175 */
176 idx--;
badc303a 177 for (; idx >= 0; idx--) {
6af83b38
SP
178 cx = cpuidle_get_statedata(&dev->states[idx]);
179 if (cx->valid) {
180 next = &dev->states[idx];
181 break;
182 }
183 }
184 /*
badc303a 185 * C1 is always valid.
6af83b38
SP
186 * So, no need to check for 'next==NULL' outside this loop.
187 */
188 }
189
190 return next;
191}
192
99e6a4d2
RN
193/**
194 * omap3_enter_idle_bm - Checks for any bus activity
195 * @dev: cpuidle device
196 * @state: The target state to be programmed
197 *
badc303a
JP
198 * This function checks for any pending activity and then programs
199 * the device to the specified or a safer state.
99e6a4d2
RN
200 */
201static int omap3_enter_idle_bm(struct cpuidle_device *dev,
202 struct cpuidle_state *state)
203{
c6cd91de
JP
204 struct cpuidle_state *new_state;
205 u32 core_next_state, per_next_state = 0, per_saved_state = 0, cam_state;
badc303a 206 struct omap3_idle_statedata *cx;
e7410cf7 207 int ret;
0f724ed9 208
c6cd91de 209 if (!omap3_can_sleep()) {
0f724ed9 210 new_state = dev->safe_state;
e7410cf7
KH
211 goto select_state;
212 }
213
e7410cf7
KH
214 /*
215 * Prevent idle completely if CAM is active.
216 * CAM does not have wakeup capability in OMAP3.
217 */
218 cam_state = pwrdm_read_pwrst(cam_pd);
219 if (cam_state == PWRDM_POWER_ON) {
220 new_state = dev->safe_state;
221 goto select_state;
222 }
223
c6cd91de
JP
224 /*
225 * FIXME: we currently manage device-specific idle states
226 * for PER and CORE in combination with CPU-specific
227 * idle states. This is wrong, and device-specific
228 * idle management needs to be separated out into
229 * its own code.
230 */
231
e7410cf7
KH
232 /*
233 * Prevent PER off if CORE is not in retention or off as this
234 * would disable PER wakeups completely.
235 */
c6cd91de
JP
236 cx = cpuidle_get_statedata(state);
237 core_next_state = cx->core_state;
e7410cf7
KH
238 per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd);
239 if ((per_next_state == PWRDM_POWER_OFF) &&
65707fb3 240 (core_next_state > PWRDM_POWER_RET))
e7410cf7 241 per_next_state = PWRDM_POWER_RET;
0f724ed9 242
e7410cf7
KH
243 /* Are we changing PER target state? */
244 if (per_next_state != per_saved_state)
245 pwrdm_set_next_pwrst(per_pd, per_next_state);
246
c6cd91de
JP
247 new_state = next_valid_state(dev, state);
248
e7410cf7 249select_state:
0f724ed9 250 dev->last_state = new_state;
e7410cf7
KH
251 ret = omap3_enter_idle(dev, new_state);
252
253 /* Restore original PER state if it was modified */
254 if (per_next_state != per_saved_state)
255 pwrdm_set_next_pwrst(per_pd, per_saved_state);
256
257 return ret;
99e6a4d2
RN
258}
259
260DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
261
6af83b38 262/**
80723c3f 263 * omap3_cpuidle_update_states() - Update the cpuidle states
25985edc
LDM
264 * @mpu_deepest_state: Enable states up to and including this for mpu domain
265 * @core_deepest_state: Enable states up to and including this for core domain
6af83b38 266 *
80723c3f
NM
267 * This goes through the list of states available and enables and disables the
268 * validity of C states based on deepest state that can be achieved for the
269 * variable domain
6af83b38 270 */
80723c3f 271void omap3_cpuidle_update_states(u32 mpu_deepest_state, u32 core_deepest_state)
6af83b38
SP
272{
273 int i;
274
badc303a
JP
275 for (i = 0; i < OMAP3_NUM_STATES; i++) {
276 struct omap3_idle_statedata *cx = &omap3_idle_data[i];
6af83b38 277
80723c3f
NM
278 if ((cx->mpu_state >= mpu_deepest_state) &&
279 (cx->core_state >= core_deepest_state)) {
6af83b38
SP
280 cx->valid = 1;
281 } else {
80723c3f 282 cx->valid = 0;
6af83b38
SP
283 }
284 }
285}
286
bb4de3df
KH
287void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
288{
289 int i;
290
291 if (!cpuidle_board_params)
292 return;
293
badc303a
JP
294 for (i = 0; i < OMAP3_NUM_STATES; i++) {
295 cpuidle_params_table[i].valid = cpuidle_board_params[i].valid;
866ba0ef
JP
296 cpuidle_params_table[i].exit_latency =
297 cpuidle_board_params[i].exit_latency;
298 cpuidle_params_table[i].target_residency =
299 cpuidle_board_params[i].target_residency;
bb4de3df
KH
300 }
301 return;
302}
303
99e6a4d2
RN
304struct cpuidle_driver omap3_idle_driver = {
305 .name = "omap3_idle",
306 .owner = THIS_MODULE,
307};
308
c6cd91de 309/* Helper to fill the C-state common data and register the driver_data */
badc303a
JP
310static inline struct omap3_idle_statedata *_fill_cstate(
311 struct cpuidle_device *dev,
312 int idx, const char *descr)
313{
314 struct omap3_idle_statedata *cx = &omap3_idle_data[idx];
315 struct cpuidle_state *state = &dev->states[idx];
316
317 state->exit_latency = cpuidle_params_table[idx].exit_latency;
318 state->target_residency = cpuidle_params_table[idx].target_residency;
319 state->flags = CPUIDLE_FLAG_TIME_VALID;
320 state->enter = omap3_enter_idle_bm;
321 cx->valid = cpuidle_params_table[idx].valid;
322 sprintf(state->name, "C%d", idx + 1);
323 strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
324 cpuidle_set_statedata(state, cx);
325
326 return cx;
327}
328
99e6a4d2
RN
329/**
330 * omap3_idle_init - Init routine for OMAP3 idle
331 *
badc303a 332 * Registers the OMAP3 specific cpuidle driver to the cpuidle
99e6a4d2
RN
333 * framework with the valid set of states.
334 */
0343371e 335int __init omap3_idle_init(void)
99e6a4d2 336{
99e6a4d2 337 struct cpuidle_device *dev;
badc303a 338 struct omap3_idle_statedata *cx;
99e6a4d2
RN
339
340 mpu_pd = pwrdm_lookup("mpu_pwrdm");
20b01669 341 core_pd = pwrdm_lookup("core_pwrdm");
e7410cf7
KH
342 per_pd = pwrdm_lookup("per_pwrdm");
343 cam_pd = pwrdm_lookup("cam_pwrdm");
99e6a4d2 344
99e6a4d2 345 cpuidle_register_driver(&omap3_idle_driver);
99e6a4d2
RN
346 dev = &per_cpu(omap3_idle_dev, smp_processor_id());
347
badc303a
JP
348 /* C1 . MPU WFI + Core active */
349 cx = _fill_cstate(dev, 0, "MPU ON + CORE ON");
350 (&dev->states[0])->enter = omap3_enter_idle;
351 dev->safe_state = &dev->states[0];
352 cx->valid = 1; /* C1 is always valid */
353 cx->mpu_state = PWRDM_POWER_ON;
354 cx->core_state = PWRDM_POWER_ON;
355
356 /* C2 . MPU WFI + Core inactive */
357 cx = _fill_cstate(dev, 1, "MPU ON + CORE ON");
358 cx->mpu_state = PWRDM_POWER_ON;
359 cx->core_state = PWRDM_POWER_ON;
360
361 /* C3 . MPU CSWR + Core inactive */
362 cx = _fill_cstate(dev, 2, "MPU RET + CORE ON");
363 cx->mpu_state = PWRDM_POWER_RET;
364 cx->core_state = PWRDM_POWER_ON;
365
366 /* C4 . MPU OFF + Core inactive */
367 cx = _fill_cstate(dev, 3, "MPU OFF + CORE ON");
368 cx->mpu_state = PWRDM_POWER_OFF;
369 cx->core_state = PWRDM_POWER_ON;
370
371 /* C5 . MPU RET + Core RET */
372 cx = _fill_cstate(dev, 4, "MPU RET + CORE RET");
373 cx->mpu_state = PWRDM_POWER_RET;
374 cx->core_state = PWRDM_POWER_RET;
99e6a4d2 375
badc303a
JP
376 /* C6 . MPU OFF + Core RET */
377 cx = _fill_cstate(dev, 5, "MPU OFF + CORE RET");
378 cx->mpu_state = PWRDM_POWER_OFF;
379 cx->core_state = PWRDM_POWER_RET;
380
381 /* C7 . MPU OFF + Core OFF */
382 cx = _fill_cstate(dev, 6, "MPU OFF + CORE OFF");
383 /*
384 * Erratum i583: implementation for ES rev < Es1.2 on 3630. We cannot
385 * enable OFF mode in a stable form for previous revisions.
386 * We disable C7 state as a result.
387 */
388 if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583)) {
389 cx->valid = 0;
390 pr_warn("%s: core off state C7 disabled due to i583\n",
391 __func__);
392 }
393 cx->mpu_state = PWRDM_POWER_OFF;
394 cx->core_state = PWRDM_POWER_OFF;
99e6a4d2 395
80723c3f
NM
396 if (enable_off_mode)
397 omap3_cpuidle_update_states(PWRDM_POWER_OFF, PWRDM_POWER_OFF);
398 else
399 omap3_cpuidle_update_states(PWRDM_POWER_RET, PWRDM_POWER_RET);
6af83b38 400
badc303a 401 dev->state_count = OMAP3_NUM_STATES;
99e6a4d2
RN
402 if (cpuidle_register_device(dev)) {
403 printk(KERN_ERR "%s: CPUidle register device failed\n",
404 __func__);
405 return -EIO;
406 }
407
408 return 0;
409}
0343371e
KJ
410#else
411int __init omap3_idle_init(void)
412{
413 return 0;
414}
99e6a4d2 415#endif /* CONFIG_CPU_IDLE */
This page took 0.130815 seconds and 5 git commands to generate.