1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/arch/arm/mach-omap2/cpuidle34xx.c
4 *
5 * OMAP3 CPU IDLE Routines
6 *
7 * Copyright (C) 2008 Texas Instruments, Inc.
8 * Rajendra Nayak <rnayak@ti.com>
9 *
10 * Copyright (C) 2007 Texas Instruments, Inc.
11 * Karthik Dasu <karthik-dp@ti.com>
12 *
13 * Copyright (C) 2006 Nokia Corporation
14 * Tony Lindgren <tony@atomide.com>
15 *
16 * Copyright (C) 2005 Texas Instruments, Inc.
17 * Richard Woodruff <r-woodruff2@ti.com>
18 *
19 * Based on pm.c for omap2
20 */
21
22 #include <linux/sched.h>
23 #include <linux/cpuidle.h>
24 #include <linux/export.h>
25 #include <linux/cpu_pm.h>
26 #include <asm/cpuidle.h>
27
28 #include "powerdomain.h"
29 #include "clockdomain.h"
30
31 #include "pm.h"
32 #include "control.h"
33 #include "common.h"
34 #include "soc.h"
35
36 /* Mach specific information to be recorded in the C-state driver_data */
37 struct omap3_idle_statedata {
38 u8 mpu_state;
39 u8 core_state;
40 u8 per_min_state;
41 u8 flags;
42 };
43
44 static struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
45
46 /*
47 * Possible flag bits for struct omap3_idle_statedata.flags:
48 *
49 * OMAP_CPUIDLE_CX_NO_CLKDM_IDLE: don't allow the MPU clockdomain to go
50 * inactive. This in turn prevents the MPU DPLL from entering autoidle
51 * mode, so wakeup latency is greatly reduced, at the cost of additional
52 * energy consumption. This also prevents the CORE clockdomain from
53 * entering idle.
54 */
55 #define OMAP_CPUIDLE_CX_NO_CLKDM_IDLE BIT(0)
56
57 /*
58 * Prevent PER OFF if CORE is not in RETention or OFF as this would
59 * disable PER wakeups completely.
60 */
61 static struct omap3_idle_statedata omap3_idle_data[] = {
62 {
63 .mpu_state = PWRDM_POWER_ON,
64 .core_state = PWRDM_POWER_ON,
65 /* In C1 do not allow PER state lower than CORE state */
66 .per_min_state = PWRDM_POWER_ON,
67 .flags = OMAP_CPUIDLE_CX_NO_CLKDM_IDLE,
68 },
69 {
70 .mpu_state = PWRDM_POWER_ON,
71 .core_state = PWRDM_POWER_ON,
72 .per_min_state = PWRDM_POWER_RET,
73 },
74 {
75 .mpu_state = PWRDM_POWER_RET,
76 .core_state = PWRDM_POWER_ON,
77 .per_min_state = PWRDM_POWER_RET,
78 },
79 {
80 .mpu_state = PWRDM_POWER_OFF,
81 .core_state = PWRDM_POWER_ON,
82 .per_min_state = PWRDM_POWER_RET,
83 },
84 {
85 .mpu_state = PWRDM_POWER_RET,
86 .core_state = PWRDM_POWER_RET,
87 .per_min_state = PWRDM_POWER_OFF,
88 },
89 {
90 .mpu_state = PWRDM_POWER_OFF,
91 .core_state = PWRDM_POWER_RET,
92 .per_min_state = PWRDM_POWER_OFF,
93 },
94 {
95 .mpu_state = PWRDM_POWER_OFF,
96 .core_state = PWRDM_POWER_OFF,
97 .per_min_state = PWRDM_POWER_OFF,
98 },
99 };
100
101 /**
102 * omap3_enter_idle - Programs OMAP3 to enter the specified state
103 * @dev: cpuidle device
104 * @drv: cpuidle driver
105 * @index: the index of state to be entered
106 */
omap3_enter_idle(struct cpuidle_device * dev,struct cpuidle_driver * drv,int index)107 static int omap3_enter_idle(struct cpuidle_device *dev,
108 struct cpuidle_driver *drv,
109 int index)
110 {
111 struct omap3_idle_statedata *cx = &omap3_idle_data[index];
112 int error;
113
114 if (omap_irq_pending() || need_resched())
115 goto return_sleep_time;
116
117 /* Deny idle for C1 */
118 if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE) {
119 clkdm_deny_idle(mpu_pd->pwrdm_clkdms[0]);
120 } else {
121 pwrdm_set_next_pwrst(mpu_pd, cx->mpu_state);
122 pwrdm_set_next_pwrst(core_pd, cx->core_state);
123 }
124
125 /*
126 * Call idle CPU PM enter notifier chain so that
127 * VFP context is saved.
128 */
129 if (cx->mpu_state == PWRDM_POWER_OFF) {
130 error = cpu_pm_enter();
131 if (error)
132 goto out_clkdm_set;
133 }
134
135 /* Execute ARM wfi */
136 omap_sram_idle(true);
137
138 /*
139 * Call idle CPU PM enter notifier chain to restore
140 * VFP context.
141 */
142 if (cx->mpu_state == PWRDM_POWER_OFF &&
143 pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF)
144 cpu_pm_exit();
145
146 out_clkdm_set:
147 /* Re-allow idle for C1 */
148 if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE)
149 clkdm_allow_idle(mpu_pd->pwrdm_clkdms[0]);
150
151 return_sleep_time:
152
153 return index;
154 }
155
156 /**
157 * next_valid_state - Find next valid C-state
158 * @dev: cpuidle device
159 * @drv: cpuidle driver
160 * @index: Index of currently selected c-state
161 *
162 * If the state corresponding to index is valid, index is returned back
163 * to the caller. Else, this function searches for a lower c-state which is
164 * still valid (as defined in omap3_power_states[]) and returns its index.
165 *
166 * A state is valid if the 'valid' field is enabled and
167 * if it satisfies the enable_off_mode condition.
168 */
next_valid_state(struct cpuidle_device * dev,struct cpuidle_driver * drv,int index)169 static int next_valid_state(struct cpuidle_device *dev,
170 struct cpuidle_driver *drv, int index)
171 {
172 struct omap3_idle_statedata *cx = &omap3_idle_data[index];
173 u32 mpu_deepest_state = PWRDM_POWER_RET;
174 u32 core_deepest_state = PWRDM_POWER_RET;
175 int idx;
176 int next_index = 0; /* C1 is the default value */
177
178 if (enable_off_mode) {
179 mpu_deepest_state = PWRDM_POWER_OFF;
180 /*
181 * Erratum i583: valable for ES rev < Es1.2 on 3630.
182 * CORE OFF mode is not supported in a stable form, restrict
183 * instead the CORE state to RET.
184 */
185 if (!IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583))
186 core_deepest_state = PWRDM_POWER_OFF;
187 }
188
189 /* Check if current state is valid */
190 if ((cx->mpu_state >= mpu_deepest_state) &&
191 (cx->core_state >= core_deepest_state))
192 return index;
193
194 /*
195 * Drop to next valid state.
196 * Start search from the next (lower) state.
197 */
198 for (idx = index - 1; idx >= 0; idx--) {
199 cx = &omap3_idle_data[idx];
200 if ((cx->mpu_state >= mpu_deepest_state) &&
201 (cx->core_state >= core_deepest_state)) {
202 next_index = idx;
203 break;
204 }
205 }
206
207 return next_index;
208 }
209
210 /**
211 * omap3_enter_idle_bm - Checks for any bus activity
212 * @dev: cpuidle device
213 * @drv: cpuidle driver
214 * @index: array index of target state to be programmed
215 *
216 * This function checks for any pending activity and then programs
217 * the device to the specified or a safer state.
218 */
omap3_enter_idle_bm(struct cpuidle_device * dev,struct cpuidle_driver * drv,int index)219 static int omap3_enter_idle_bm(struct cpuidle_device *dev,
220 struct cpuidle_driver *drv,
221 int index)
222 {
223 int new_state_idx, ret;
224 u8 per_next_state, per_saved_state;
225 struct omap3_idle_statedata *cx;
226
227 /*
228 * Use only C1 if CAM is active.
229 * CAM does not have wakeup capability in OMAP3.
230 */
231 if (pwrdm_read_pwrst(cam_pd) == PWRDM_POWER_ON)
232 new_state_idx = drv->safe_state_index;
233 else
234 new_state_idx = next_valid_state(dev, drv, index);
235
236 /*
237 * FIXME: we currently manage device-specific idle states
238 * for PER and CORE in combination with CPU-specific
239 * idle states. This is wrong, and device-specific
240 * idle management needs to be separated out into
241 * its own code.
242 */
243
244 /* Program PER state */
245 cx = &omap3_idle_data[new_state_idx];
246
247 per_next_state = pwrdm_read_next_pwrst(per_pd);
248 per_saved_state = per_next_state;
249 if (per_next_state < cx->per_min_state) {
250 per_next_state = cx->per_min_state;
251 pwrdm_set_next_pwrst(per_pd, per_next_state);
252 }
253
254 ret = omap3_enter_idle(dev, drv, new_state_idx);
255
256 /* Restore original PER state if it was modified */
257 if (per_next_state != per_saved_state)
258 pwrdm_set_next_pwrst(per_pd, per_saved_state);
259
260 return ret;
261 }
262
263 static struct cpuidle_driver omap3_idle_driver = {
264 .name = "omap3_idle",
265 .owner = THIS_MODULE,
266 .states = {
267 {
268 .flags = CPUIDLE_FLAG_RCU_IDLE,
269 .enter = omap3_enter_idle_bm,
270 .exit_latency = 2 + 2,
271 .target_residency = 5,
272 .name = "C1",
273 .desc = "MPU ON + CORE ON",
274 },
275 {
276 .flags = CPUIDLE_FLAG_RCU_IDLE,
277 .enter = omap3_enter_idle_bm,
278 .exit_latency = 10 + 10,
279 .target_residency = 30,
280 .name = "C2",
281 .desc = "MPU ON + CORE ON",
282 },
283 {
284 .flags = CPUIDLE_FLAG_RCU_IDLE,
285 .enter = omap3_enter_idle_bm,
286 .exit_latency = 50 + 50,
287 .target_residency = 300,
288 .name = "C3",
289 .desc = "MPU RET + CORE ON",
290 },
291 {
292 .flags = CPUIDLE_FLAG_RCU_IDLE,
293 .enter = omap3_enter_idle_bm,
294 .exit_latency = 1500 + 1800,
295 .target_residency = 4000,
296 .name = "C4",
297 .desc = "MPU OFF + CORE ON",
298 },
299 {
300 .flags = CPUIDLE_FLAG_RCU_IDLE,
301 .enter = omap3_enter_idle_bm,
302 .exit_latency = 2500 + 7500,
303 .target_residency = 12000,
304 .name = "C5",
305 .desc = "MPU RET + CORE RET",
306 },
307 {
308 .flags = CPUIDLE_FLAG_RCU_IDLE,
309 .enter = omap3_enter_idle_bm,
310 .exit_latency = 3000 + 8500,
311 .target_residency = 15000,
312 .name = "C6",
313 .desc = "MPU OFF + CORE RET",
314 },
315 {
316 .flags = CPUIDLE_FLAG_RCU_IDLE,
317 .enter = omap3_enter_idle_bm,
318 .exit_latency = 10000 + 30000,
319 .target_residency = 30000,
320 .name = "C7",
321 .desc = "MPU OFF + CORE OFF",
322 },
323 },
324 .state_count = ARRAY_SIZE(omap3_idle_data),
325 .safe_state_index = 0,
326 };
327
328 /*
329 * Numbers based on measurements made in October 2009 for PM optimized kernel
330 * with CPU freq enabled on device Nokia N900. Assumes OPP2 (main idle OPP,
331 * and worst case latencies).
332 */
333 static struct cpuidle_driver omap3430_idle_driver = {
334 .name = "omap3430_idle",
335 .owner = THIS_MODULE,
336 .states = {
337 {
338 .flags = CPUIDLE_FLAG_RCU_IDLE,
339 .enter = omap3_enter_idle_bm,
340 .exit_latency = 110 + 162,
341 .target_residency = 5,
342 .name = "C1",
343 .desc = "MPU ON + CORE ON",
344 },
345 {
346 .flags = CPUIDLE_FLAG_RCU_IDLE,
347 .enter = omap3_enter_idle_bm,
348 .exit_latency = 106 + 180,
349 .target_residency = 309,
350 .name = "C2",
351 .desc = "MPU ON + CORE ON",
352 },
353 {
354 .flags = CPUIDLE_FLAG_RCU_IDLE,
355 .enter = omap3_enter_idle_bm,
356 .exit_latency = 107 + 410,
357 .target_residency = 46057,
358 .name = "C3",
359 .desc = "MPU RET + CORE ON",
360 },
361 {
362 .flags = CPUIDLE_FLAG_RCU_IDLE,
363 .enter = omap3_enter_idle_bm,
364 .exit_latency = 121 + 3374,
365 .target_residency = 46057,
366 .name = "C4",
367 .desc = "MPU OFF + CORE ON",
368 },
369 {
370 .flags = CPUIDLE_FLAG_RCU_IDLE,
371 .enter = omap3_enter_idle_bm,
372 .exit_latency = 855 + 1146,
373 .target_residency = 46057,
374 .name = "C5",
375 .desc = "MPU RET + CORE RET",
376 },
377 {
378 .flags = CPUIDLE_FLAG_RCU_IDLE,
379 .enter = omap3_enter_idle_bm,
380 .exit_latency = 7580 + 4134,
381 .target_residency = 484329,
382 .name = "C6",
383 .desc = "MPU OFF + CORE RET",
384 },
385 {
386 .flags = CPUIDLE_FLAG_RCU_IDLE,
387 .enter = omap3_enter_idle_bm,
388 .exit_latency = 7505 + 15274,
389 .target_residency = 484329,
390 .name = "C7",
391 .desc = "MPU OFF + CORE OFF",
392 },
393 },
394 .state_count = ARRAY_SIZE(omap3_idle_data),
395 .safe_state_index = 0,
396 };
397
398 /* Public functions */
399
400 /**
401 * omap3_idle_init - Init routine for OMAP3 idle
402 *
403 * Registers the OMAP3 specific cpuidle driver to the cpuidle
404 * framework with the valid set of states.
405 */
omap3_idle_init(void)406 int __init omap3_idle_init(void)
407 {
408 mpu_pd = pwrdm_lookup("mpu_pwrdm");
409 core_pd = pwrdm_lookup("core_pwrdm");
410 per_pd = pwrdm_lookup("per_pwrdm");
411 cam_pd = pwrdm_lookup("cam_pwrdm");
412
413 if (!mpu_pd || !core_pd || !per_pd || !cam_pd)
414 return -ENODEV;
415
416 if (cpu_is_omap3430())
417 return cpuidle_register(&omap3430_idle_driver, NULL);
418 else
419 return cpuidle_register(&omap3_idle_driver, NULL);
420 }
421