2 * linux/arch/arm/mach-omap2/cpuidle34xx.c
4 * OMAP3 CPU IDLE Routines
6 * Copyright (C) 2008 Texas Instruments, Inc.
7 * Rajendra Nayak <rnayak@ti.com>
9 * Copyright (C) 2007 Texas Instruments, Inc.
10 * Karthik Dasu <karthik-dp@ti.com>
12 * Copyright (C) 2006 Nokia Corporation
13 * Tony Lindgren <tony@atomide.com>
15 * Copyright (C) 2005 Texas Instruments, Inc.
16 * Richard Woodruff <r-woodruff2@ti.com>
18 * Based on pm.c for omap2
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.
25 #include <linux/sched.h>
26 #include <linux/cpuidle.h>
28 #include <plat/prcm.h>
29 #include <plat/irqs.h>
30 #include "powerdomain.h"
31 #include "clockdomain.h"
32 #include <plat/serial.h>
37 #ifdef CONFIG_CPU_IDLE
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.
46 static struct cpuidle_params cpuidle_params_table
[] = {
54 {1500 + 1800, 4000, 1},
56 {2500 + 7500, 12000, 1},
58 {3000 + 8500, 15000, 1},
60 {10000 + 30000, 300000, 1},
62 #define OMAP3_NUM_STATES ARRAY_SIZE(cpuidle_params_table)
64 /* Mach specific information to be recorded in the C-state driver_data */
65 struct omap3_idle_statedata
{
70 struct omap3_idle_statedata omap3_idle_data
[OMAP3_NUM_STATES
];
72 struct powerdomain
*mpu_pd
, *core_pd
, *per_pd
, *cam_pd
;
74 static int _cpuidle_allow_idle(struct powerdomain
*pwrdm
,
75 struct clockdomain
*clkdm
)
77 clkdm_allow_idle(clkdm
);
81 static int _cpuidle_deny_idle(struct powerdomain
*pwrdm
,
82 struct clockdomain
*clkdm
)
84 clkdm_deny_idle(clkdm
);
89 * omap3_enter_idle - Programs OMAP3 to enter the specified state
90 * @dev: cpuidle device
91 * @state: The target state to be programmed
93 * Called from the CPUidle framework to program the device to the
94 * specified target state selected by the governor.
96 static int omap3_enter_idle(struct cpuidle_device
*dev
,
97 struct cpuidle_state
*state
)
99 struct omap3_idle_statedata
*cx
= cpuidle_get_statedata(state
);
100 struct timespec ts_preidle
, ts_postidle
, ts_idle
;
101 u32 mpu_state
= cx
->mpu_state
, core_state
= cx
->core_state
;
103 /* Used to keep track of the total time in idle */
104 getnstimeofday(&ts_preidle
);
109 pwrdm_set_next_pwrst(mpu_pd
, mpu_state
);
110 pwrdm_set_next_pwrst(core_pd
, core_state
);
112 if (omap_irq_pending() || need_resched())
113 goto return_sleep_time
;
115 /* Deny idle for C1 */
116 if (state
== &dev
->states
[0]) {
117 pwrdm_for_each_clkdm(mpu_pd
, _cpuidle_deny_idle
);
118 pwrdm_for_each_clkdm(core_pd
, _cpuidle_deny_idle
);
121 /* Execute ARM wfi */
124 /* Re-allow idle for C1 */
125 if (state
== &dev
->states
[0]) {
126 pwrdm_for_each_clkdm(mpu_pd
, _cpuidle_allow_idle
);
127 pwrdm_for_each_clkdm(core_pd
, _cpuidle_allow_idle
);
131 getnstimeofday(&ts_postidle
);
132 ts_idle
= timespec_sub(ts_postidle
, ts_preidle
);
137 return ts_idle
.tv_nsec
/ NSEC_PER_USEC
+ ts_idle
.tv_sec
* USEC_PER_SEC
;
141 * next_valid_state - Find next valid C-state
142 * @dev: cpuidle device
143 * @state: Currently selected C-state
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
149 * A state is valid if the 'valid' field is enabled and
150 * if it satisfies the enable_off_mode condition.
152 static struct cpuidle_state
*next_valid_state(struct cpuidle_device
*dev
,
153 struct cpuidle_state
*curr
)
155 struct cpuidle_state
*next
= NULL
;
156 struct omap3_idle_statedata
*cx
= cpuidle_get_statedata(curr
);
157 u32 mpu_deepest_state
= PWRDM_POWER_RET
;
158 u32 core_deepest_state
= PWRDM_POWER_RET
;
160 if (enable_off_mode
) {
161 mpu_deepest_state
= PWRDM_POWER_OFF
;
163 * Erratum i583: valable for ES rev < Es1.2 on 3630.
164 * CORE OFF mode is not supported in a stable form, restrict
165 * instead the CORE state to RET.
167 if (!IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583
))
168 core_deepest_state
= PWRDM_POWER_OFF
;
171 /* Check if current state is valid */
173 (cx
->mpu_state
>= mpu_deepest_state
) &&
174 (cx
->core_state
>= core_deepest_state
)) {
177 int idx
= OMAP3_NUM_STATES
- 1;
179 /* Reach the current state starting at highest C-state */
180 for (; idx
>= 0; idx
--) {
181 if (&dev
->states
[idx
] == curr
) {
182 next
= &dev
->states
[idx
];
187 /* Should never hit this condition */
188 WARN_ON(next
== NULL
);
191 * Drop to next valid state.
192 * Start search from the next (lower) state.
195 for (; idx
>= 0; idx
--) {
196 cx
= cpuidle_get_statedata(&dev
->states
[idx
]);
198 (cx
->mpu_state
>= mpu_deepest_state
) &&
199 (cx
->core_state
>= core_deepest_state
)) {
200 next
= &dev
->states
[idx
];
205 * C1 is always valid.
206 * So, no need to check for 'next==NULL' outside this loop.
214 * omap3_enter_idle_bm - Checks for any bus activity
215 * @dev: cpuidle device
216 * @state: The target state to be programmed
218 * This function checks for any pending activity and then programs
219 * the device to the specified or a safer state.
221 static int omap3_enter_idle_bm(struct cpuidle_device
*dev
,
222 struct cpuidle_state
*state
)
224 struct cpuidle_state
*new_state
;
225 u32 core_next_state
, per_next_state
= 0, per_saved_state
= 0, cam_state
;
226 struct omap3_idle_statedata
*cx
;
229 if (!omap3_can_sleep()) {
230 new_state
= dev
->safe_state
;
235 * Prevent idle completely if CAM is active.
236 * CAM does not have wakeup capability in OMAP3.
238 cam_state
= pwrdm_read_pwrst(cam_pd
);
239 if (cam_state
== PWRDM_POWER_ON
) {
240 new_state
= dev
->safe_state
;
245 * FIXME: we currently manage device-specific idle states
246 * for PER and CORE in combination with CPU-specific
247 * idle states. This is wrong, and device-specific
248 * idle management needs to be separated out into
253 * Prevent PER off if CORE is not in retention or off as this
254 * would disable PER wakeups completely.
256 cx
= cpuidle_get_statedata(state
);
257 core_next_state
= cx
->core_state
;
258 per_next_state
= per_saved_state
= pwrdm_read_next_pwrst(per_pd
);
259 if ((per_next_state
== PWRDM_POWER_OFF
) &&
260 (core_next_state
> PWRDM_POWER_RET
))
261 per_next_state
= PWRDM_POWER_RET
;
263 /* Are we changing PER target state? */
264 if (per_next_state
!= per_saved_state
)
265 pwrdm_set_next_pwrst(per_pd
, per_next_state
);
267 new_state
= next_valid_state(dev
, state
);
270 dev
->last_state
= new_state
;
271 ret
= omap3_enter_idle(dev
, new_state
);
273 /* Restore original PER state if it was modified */
274 if (per_next_state
!= per_saved_state
)
275 pwrdm_set_next_pwrst(per_pd
, per_saved_state
);
280 DEFINE_PER_CPU(struct cpuidle_device
, omap3_idle_dev
);
282 void omap3_pm_init_cpuidle(struct cpuidle_params
*cpuidle_board_params
)
286 if (!cpuidle_board_params
)
289 for (i
= 0; i
< OMAP3_NUM_STATES
; i
++) {
290 cpuidle_params_table
[i
].valid
= cpuidle_board_params
[i
].valid
;
291 cpuidle_params_table
[i
].exit_latency
=
292 cpuidle_board_params
[i
].exit_latency
;
293 cpuidle_params_table
[i
].target_residency
=
294 cpuidle_board_params
[i
].target_residency
;
299 struct cpuidle_driver omap3_idle_driver
= {
300 .name
= "omap3_idle",
301 .owner
= THIS_MODULE
,
304 /* Helper to fill the C-state common data and register the driver_data */
305 static inline struct omap3_idle_statedata
*_fill_cstate(
306 struct cpuidle_device
*dev
,
307 int idx
, const char *descr
)
309 struct omap3_idle_statedata
*cx
= &omap3_idle_data
[idx
];
310 struct cpuidle_state
*state
= &dev
->states
[idx
];
312 state
->exit_latency
= cpuidle_params_table
[idx
].exit_latency
;
313 state
->target_residency
= cpuidle_params_table
[idx
].target_residency
;
314 state
->flags
= CPUIDLE_FLAG_TIME_VALID
;
315 state
->enter
= omap3_enter_idle_bm
;
316 cx
->valid
= cpuidle_params_table
[idx
].valid
;
317 sprintf(state
->name
, "C%d", idx
+ 1);
318 strncpy(state
->desc
, descr
, CPUIDLE_DESC_LEN
);
319 cpuidle_set_statedata(state
, cx
);
325 * omap3_idle_init - Init routine for OMAP3 idle
327 * Registers the OMAP3 specific cpuidle driver to the cpuidle
328 * framework with the valid set of states.
330 int __init
omap3_idle_init(void)
332 struct cpuidle_device
*dev
;
333 struct omap3_idle_statedata
*cx
;
335 mpu_pd
= pwrdm_lookup("mpu_pwrdm");
336 core_pd
= pwrdm_lookup("core_pwrdm");
337 per_pd
= pwrdm_lookup("per_pwrdm");
338 cam_pd
= pwrdm_lookup("cam_pwrdm");
340 cpuidle_register_driver(&omap3_idle_driver
);
341 dev
= &per_cpu(omap3_idle_dev
, smp_processor_id());
343 /* C1 . MPU WFI + Core active */
344 cx
= _fill_cstate(dev
, 0, "MPU ON + CORE ON");
345 (&dev
->states
[0])->enter
= omap3_enter_idle
;
346 dev
->safe_state
= &dev
->states
[0];
347 cx
->valid
= 1; /* C1 is always valid */
348 cx
->mpu_state
= PWRDM_POWER_ON
;
349 cx
->core_state
= PWRDM_POWER_ON
;
351 /* C2 . MPU WFI + Core inactive */
352 cx
= _fill_cstate(dev
, 1, "MPU ON + CORE ON");
353 cx
->mpu_state
= PWRDM_POWER_ON
;
354 cx
->core_state
= PWRDM_POWER_ON
;
356 /* C3 . MPU CSWR + Core inactive */
357 cx
= _fill_cstate(dev
, 2, "MPU RET + CORE ON");
358 cx
->mpu_state
= PWRDM_POWER_RET
;
359 cx
->core_state
= PWRDM_POWER_ON
;
361 /* C4 . MPU OFF + Core inactive */
362 cx
= _fill_cstate(dev
, 3, "MPU OFF + CORE ON");
363 cx
->mpu_state
= PWRDM_POWER_OFF
;
364 cx
->core_state
= PWRDM_POWER_ON
;
366 /* C5 . MPU RET + Core RET */
367 cx
= _fill_cstate(dev
, 4, "MPU RET + CORE RET");
368 cx
->mpu_state
= PWRDM_POWER_RET
;
369 cx
->core_state
= PWRDM_POWER_RET
;
371 /* C6 . MPU OFF + Core RET */
372 cx
= _fill_cstate(dev
, 5, "MPU OFF + CORE RET");
373 cx
->mpu_state
= PWRDM_POWER_OFF
;
374 cx
->core_state
= PWRDM_POWER_RET
;
376 /* C7 . MPU OFF + Core OFF */
377 cx
= _fill_cstate(dev
, 6, "MPU OFF + CORE OFF");
379 * Erratum i583: implementation for ES rev < Es1.2 on 3630. We cannot
380 * enable OFF mode in a stable form for previous revisions.
381 * We disable C7 state as a result.
383 if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583
)) {
385 pr_warn("%s: core off state C7 disabled due to i583\n",
388 cx
->mpu_state
= PWRDM_POWER_OFF
;
389 cx
->core_state
= PWRDM_POWER_OFF
;
391 dev
->state_count
= OMAP3_NUM_STATES
;
392 if (cpuidle_register_device(dev
)) {
393 printk(KERN_ERR
"%s: CPUidle register device failed\n",
401 int __init
omap3_idle_init(void)
405 #endif /* CONFIG_CPU_IDLE */