summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-omap2/cpuidle34xx.c
blob: d3fce7b97fcfeaf852153c364d599f42ea4d8bb3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
/*
 * linux/arch/arm/mach-omap2/cpuidle34xx.c
 *
 * OMAP3 CPU IDLE Routines
 *
 * Copyright (C) 2008 Texas Instruments, Inc.
 * Rajendra Nayak <rnayak@ti.com>
 *
 * Copyright (C) 2007 Texas Instruments, Inc.
 * Karthik Dasu <karthik-dp@ti.com>
 *
 * Copyright (C) 2006 Nokia Corporation
 * Tony Lindgren <tony@atomide.com>
 *
 * Copyright (C) 2005 Texas Instruments, Inc.
 * Richard Woodruff <r-woodruff2@ti.com>
 *
 * Based on pm.c for omap2
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/sched.h>
#include <linux/cpuidle.h>

#include <plat/prcm.h>
#include <plat/irqs.h>
#include "powerdomain.h"
#include "clockdomain.h"
#include <plat/serial.h>

#include "pm.h"
#include "control.h"

#ifdef CONFIG_CPU_IDLE

/*
 * The latencies/thresholds for various C states have
 * to be configured from the respective board files.
 * These are some default values (which might not provide
 * the best power savings) used on boards which do not
 * pass these details from the board file.
 */
static struct cpuidle_params cpuidle_params_table[] = {
	/* C1 */
	{2 + 2, 5, 1},
	/* C2 */
	{10 + 10, 30, 1},
	/* C3 */
	{50 + 50, 300, 1},
	/* C4 */
	{1500 + 1800, 4000, 1},
	/* C5 */
	{2500 + 7500, 12000, 1},
	/* C6 */
	{3000 + 8500, 15000, 1},
	/* C7 */
	{10000 + 30000, 300000, 1},
};
#define OMAP3_NUM_STATES ARRAY_SIZE(cpuidle_params_table)

/* Mach specific information to be recorded in the C-state driver_data */
struct omap3_idle_statedata {
	u32 mpu_state;
	u32 core_state;
	u8 valid;
};
struct omap3_idle_statedata omap3_idle_data[OMAP3_NUM_STATES];

struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;

static int _cpuidle_allow_idle(struct powerdomain *pwrdm,
				struct clockdomain *clkdm)
{
	clkdm_allow_idle(clkdm);
	return 0;
}

static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
				struct clockdomain *clkdm)
{
	clkdm_deny_idle(clkdm);
	return 0;
}

/**
 * omap3_enter_idle - Programs OMAP3 to enter the specified state
 * @dev: cpuidle device
 * @index: the index of state to be entered
 *
 * Called from the CPUidle framework to program the device to the
 * specified target state selected by the governor.
 */
static int omap3_enter_idle(struct cpuidle_device *dev,
				int index)
{
	struct omap3_idle_statedata *cx =
			cpuidle_get_statedata(&dev->states_usage[index]);
	struct timespec ts_preidle, ts_postidle, ts_idle;
	u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
	int idle_time;

	/* Used to keep track of the total time in idle */
	getnstimeofday(&ts_preidle);

	local_irq_disable();
	local_fiq_disable();

	pwrdm_set_next_pwrst(mpu_pd, mpu_state);
	pwrdm_set_next_pwrst(core_pd, core_state);

	if (omap_irq_pending() || need_resched())
		goto return_sleep_time;

	/* Deny idle for C1 */
	if (index == 0) {
		pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
		pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
	}

	/* Execute ARM wfi */
	omap_sram_idle();

	/* Re-allow idle for C1 */
	if (index == 0) {
		pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
		pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
	}

return_sleep_time:
	getnstimeofday(&ts_postidle);
	ts_idle = timespec_sub(ts_postidle, ts_preidle);

	local_irq_enable();
	local_fiq_enable();

	idle_time = ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * \
								USEC_PER_SEC;

	/* Update cpuidle counters */
	dev->last_residency = idle_time;

	return index;
}

/**
 * next_valid_state - Find next valid C-state
 * @dev: cpuidle device
 * @index: Index of currently selected c-state
 *
 * If the state corresponding to index is valid, index is returned back
 * to the caller. Else, this function searches for a lower c-state which is
 * still valid (as defined in omap3_power_states[]) and returns its index.
 *
 * A state is valid if the 'valid' field is enabled and
 * if it satisfies the enable_off_mode condition.
 */
static int next_valid_state(struct cpuidle_device *dev,
				int index)
{
	struct cpuidle_state_usage *curr_usage = &dev->states_usage[index];
	struct cpuidle_state *curr = &dev->states[index];
	struct omap3_idle_statedata *cx = cpuidle_get_statedata(curr_usage);
	u32 mpu_deepest_state = PWRDM_POWER_RET;
	u32 core_deepest_state = PWRDM_POWER_RET;
	int next_index = -1;

	if (enable_off_mode) {
		mpu_deepest_state = PWRDM_POWER_OFF;
		/*
		 * Erratum i583: valable for ES rev < Es1.2 on 3630.
		 * CORE OFF mode is not supported in a stable form, restrict
		 * instead the CORE state to RET.
		 */
		if (!IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583))
			core_deepest_state = PWRDM_POWER_OFF;
	}

	/* Check if current state is valid */
	if ((cx->valid) &&
	    (cx->mpu_state >= mpu_deepest_state) &&
	    (cx->core_state >= core_deepest_state)) {
		return index;
	} else {
		int idx = OMAP3_NUM_STATES - 1;

		/* Reach the current state starting at highest C-state */
		for (; idx >= 0; idx--) {
			if (&dev->states[idx] == curr) {
				next_index = idx;
				break;
			}
		}

		/* Should never hit this condition */
		WARN_ON(next_index == -1);

		/*
		 * Drop to next valid state.
		 * Start search from the next (lower) state.
		 */
		idx--;
		for (; idx >= 0; idx--) {
			cx = cpuidle_get_statedata(&dev->states_usage[idx]);
			if ((cx->valid) &&
			    (cx->mpu_state >= mpu_deepest_state) &&
			    (cx->core_state >= core_deepest_state)) {
				next_index = idx;
				break;
			}
		}
		/*
		 * C1 is always valid.
		 * So, no need to check for 'next_index == -1' outside
		 * this loop.
		 */
	}

	return next_index;
}

/**
 * omap3_enter_idle_bm - Checks for any bus activity
 * @dev: cpuidle device
 * @index: array index of target state to be programmed
 *
 * This function checks for any pending activity and then programs
 * the device to the specified or a safer state.
 */
static int omap3_enter_idle_bm(struct cpuidle_device *dev,
			       int index)
{
	int new_state_idx;
	u32 core_next_state, per_next_state = 0, per_saved_state = 0, cam_state;
	struct omap3_idle_statedata *cx;
	int ret;

	if (!omap3_can_sleep()) {
		new_state_idx = dev->safe_state_index;
		goto select_state;
	}

	/*
	 * Prevent idle completely if CAM is active.
	 * CAM does not have wakeup capability in OMAP3.
	 */
	cam_state = pwrdm_read_pwrst(cam_pd);
	if (cam_state == PWRDM_POWER_ON) {
		new_state_idx = dev->safe_state_index;
		goto select_state;
	}

	/*
	 * FIXME: we currently manage device-specific idle states
	 *        for PER and CORE in combination with CPU-specific
	 *        idle states.  This is wrong, and device-specific
	 *        idle management needs to be separated out into
	 *        its own code.
	 */

	/*
	 * Prevent PER off if CORE is not in retention or off as this
	 * would disable PER wakeups completely.
	 */
	cx = cpuidle_get_statedata(&dev->states_usage[index]);
	core_next_state = cx->core_state;
	per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd);
	if ((per_next_state == PWRDM_POWER_OFF) &&
	    (core_next_state > PWRDM_POWER_RET))
		per_next_state = PWRDM_POWER_RET;

	/* Are we changing PER target state? */
	if (per_next_state != per_saved_state)
		pwrdm_set_next_pwrst(per_pd, per_next_state);

	new_state_idx = next_valid_state(dev, index);

select_state:
	ret = omap3_enter_idle(dev, new_state_idx);

	/* Restore original PER state if it was modified */
	if (per_next_state != per_saved_state)
		pwrdm_set_next_pwrst(per_pd, per_saved_state);

	return ret;
}

DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);

void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
{
	int i;

	if (!cpuidle_board_params)
		return;

	for (i = 0; i < OMAP3_NUM_STATES; i++) {
		cpuidle_params_table[i].valid =	cpuidle_board_params[i].valid;
		cpuidle_params_table[i].exit_latency =
			cpuidle_board_params[i].exit_latency;
		cpuidle_params_table[i].target_residency =
			cpuidle_board_params[i].target_residency;
	}
	return;
}

struct cpuidle_driver omap3_idle_driver = {
	.name = 	"omap3_idle",
	.owner = 	THIS_MODULE,
};

/* Helper to fill the C-state common data and register the driver_data */
static inline struct omap3_idle_statedata *_fill_cstate(
					struct cpuidle_device *dev,
					int idx, const char *descr)
{
	struct omap3_idle_statedata *cx = &omap3_idle_data[idx];
	struct cpuidle_state *state = &dev->states[idx];
	struct cpuidle_state_usage *state_usage = &dev->states_usage[idx];

	state->exit_latency	= cpuidle_params_table[idx].exit_latency;
	state->target_residency	= cpuidle_params_table[idx].target_residency;
	state->flags		= CPUIDLE_FLAG_TIME_VALID;
	state->enter		= omap3_enter_idle_bm;
	cx->valid		= cpuidle_params_table[idx].valid;
	sprintf(state->name, "C%d", idx + 1);
	strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
	cpuidle_set_statedata(state_usage, cx);

	return cx;
}

/**
 * omap3_idle_init - Init routine for OMAP3 idle
 *
 * Registers the OMAP3 specific cpuidle driver to the cpuidle
 * framework with the valid set of states.
 */
int __init omap3_idle_init(void)
{
	struct cpuidle_device *dev;
	struct omap3_idle_statedata *cx;

	mpu_pd = pwrdm_lookup("mpu_pwrdm");
	core_pd = pwrdm_lookup("core_pwrdm");
	per_pd = pwrdm_lookup("per_pwrdm");
	cam_pd = pwrdm_lookup("cam_pwrdm");

	cpuidle_register_driver(&omap3_idle_driver);
	dev = &per_cpu(omap3_idle_dev, smp_processor_id());
	dev->safe_state_index = -1;

	/* C1 . MPU WFI + Core active */
	cx = _fill_cstate(dev, 0, "MPU ON + CORE ON");
	(&dev->states[0])->enter = omap3_enter_idle;
	dev->safe_state_index = 0;
	cx->valid = 1;	/* C1 is always valid */
	cx->mpu_state = PWRDM_POWER_ON;
	cx->core_state = PWRDM_POWER_ON;

	/* C2 . MPU WFI + Core inactive */
	cx = _fill_cstate(dev, 1, "MPU ON + CORE ON");
	cx->mpu_state = PWRDM_POWER_ON;
	cx->core_state = PWRDM_POWER_ON;

	/* C3 . MPU CSWR + Core inactive */
	cx = _fill_cstate(dev, 2, "MPU RET + CORE ON");
	cx->mpu_state = PWRDM_POWER_RET;
	cx->core_state = PWRDM_POWER_ON;

	/* C4 . MPU OFF + Core inactive */
	cx = _fill_cstate(dev, 3, "MPU OFF + CORE ON");
	cx->mpu_state = PWRDM_POWER_OFF;
	cx->core_state = PWRDM_POWER_ON;

	/* C5 . MPU RET + Core RET */
	cx = _fill_cstate(dev, 4, "MPU RET + CORE RET");
	cx->mpu_state = PWRDM_POWER_RET;
	cx->core_state = PWRDM_POWER_RET;

	/* C6 . MPU OFF + Core RET */
	cx = _fill_cstate(dev, 5, "MPU OFF + CORE RET");
	cx->mpu_state = PWRDM_POWER_OFF;
	cx->core_state = PWRDM_POWER_RET;

	/* C7 . MPU OFF + Core OFF */
	cx = _fill_cstate(dev, 6, "MPU OFF + CORE OFF");
	/*
	 * Erratum i583: implementation for ES rev < Es1.2 on 3630. We cannot
	 * enable OFF mode in a stable form for previous revisions.
	 * We disable C7 state as a result.
	 */
	if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583)) {
		cx->valid = 0;
		pr_warn("%s: core off state C7 disabled due to i583\n",
			__func__);
	}
	cx->mpu_state = PWRDM_POWER_OFF;
	cx->core_state = PWRDM_POWER_OFF;

	dev->state_count = OMAP3_NUM_STATES;
	if (cpuidle_register_device(dev)) {
		printk(KERN_ERR "%s: CPUidle register device failed\n",
		       __func__);
		return -EIO;
	}

	return 0;
}
#else
int __init omap3_idle_init(void)
{
	return 0;
}
#endif /* CONFIG_CPU_IDLE */
OpenPOWER on IntegriCloud