xref: /linux/arch/arm/mach-omap2/cpuidle34xx.c (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78) 
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  */
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();
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  */
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  */
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 			.enter		  = omap3_enter_idle_bm,
269 			.exit_latency	  = 2 + 2,
270 			.target_residency = 5,
271 			.name		  = "C1",
272 			.desc		  = "MPU ON + CORE ON",
273 		},
274 		{
275 			.enter		  = omap3_enter_idle_bm,
276 			.exit_latency	  = 10 + 10,
277 			.target_residency = 30,
278 			.name		  = "C2",
279 			.desc		  = "MPU ON + CORE ON",
280 		},
281 		{
282 			.enter		  = omap3_enter_idle_bm,
283 			.exit_latency	  = 50 + 50,
284 			.target_residency = 300,
285 			.name		  = "C3",
286 			.desc		  = "MPU RET + CORE ON",
287 		},
288 		{
289 			.enter		  = omap3_enter_idle_bm,
290 			.exit_latency	  = 1500 + 1800,
291 			.target_residency = 4000,
292 			.name		  = "C4",
293 			.desc		  = "MPU OFF + CORE ON",
294 		},
295 		{
296 			.enter		  = omap3_enter_idle_bm,
297 			.exit_latency	  = 2500 + 7500,
298 			.target_residency = 12000,
299 			.name		  = "C5",
300 			.desc		  = "MPU RET + CORE RET",
301 		},
302 		{
303 			.enter		  = omap3_enter_idle_bm,
304 			.exit_latency	  = 3000 + 8500,
305 			.target_residency = 15000,
306 			.name		  = "C6",
307 			.desc		  = "MPU OFF + CORE RET",
308 		},
309 		{
310 			.enter		  = omap3_enter_idle_bm,
311 			.exit_latency	  = 10000 + 30000,
312 			.target_residency = 30000,
313 			.name		  = "C7",
314 			.desc		  = "MPU OFF + CORE OFF",
315 		},
316 	},
317 	.state_count = ARRAY_SIZE(omap3_idle_data),
318 	.safe_state_index = 0,
319 };
320 
321 /*
322  * Numbers based on measurements made in October 2009 for PM optimized kernel
323  * with CPU freq enabled on device Nokia N900. Assumes OPP2 (main idle OPP,
324  * and worst case latencies).
325  */
326 static struct cpuidle_driver omap3430_idle_driver = {
327 	.name             = "omap3430_idle",
328 	.owner            = THIS_MODULE,
329 	.states = {
330 		{
331 			.enter		  = omap3_enter_idle_bm,
332 			.exit_latency	  = 110 + 162,
333 			.target_residency = 5,
334 			.name		  = "C1",
335 			.desc		  = "MPU ON + CORE ON",
336 		},
337 		{
338 			.enter		  = omap3_enter_idle_bm,
339 			.exit_latency	  = 106 + 180,
340 			.target_residency = 309,
341 			.name		  = "C2",
342 			.desc		  = "MPU ON + CORE ON",
343 		},
344 		{
345 			.enter		  = omap3_enter_idle_bm,
346 			.exit_latency	  = 107 + 410,
347 			.target_residency = 46057,
348 			.name		  = "C3",
349 			.desc		  = "MPU RET + CORE ON",
350 		},
351 		{
352 			.enter		  = omap3_enter_idle_bm,
353 			.exit_latency	  = 121 + 3374,
354 			.target_residency = 46057,
355 			.name		  = "C4",
356 			.desc		  = "MPU OFF + CORE ON",
357 		},
358 		{
359 			.enter		  = omap3_enter_idle_bm,
360 			.exit_latency	  = 855 + 1146,
361 			.target_residency = 46057,
362 			.name		  = "C5",
363 			.desc		  = "MPU RET + CORE RET",
364 		},
365 		{
366 			.enter		  = omap3_enter_idle_bm,
367 			.exit_latency	  = 7580 + 4134,
368 			.target_residency = 484329,
369 			.name		  = "C6",
370 			.desc		  = "MPU OFF + CORE RET",
371 		},
372 		{
373 			.enter		  = omap3_enter_idle_bm,
374 			.exit_latency	  = 7505 + 15274,
375 			.target_residency = 484329,
376 			.name		  = "C7",
377 			.desc		  = "MPU OFF + CORE OFF",
378 		},
379 	},
380 	.state_count = ARRAY_SIZE(omap3_idle_data),
381 	.safe_state_index = 0,
382 };
383 
384 /* Public functions */
385 
386 /**
387  * omap3_idle_init - Init routine for OMAP3 idle
388  *
389  * Registers the OMAP3 specific cpuidle driver to the cpuidle
390  * framework with the valid set of states.
391  */
392 int __init omap3_idle_init(void)
393 {
394 	mpu_pd = pwrdm_lookup("mpu_pwrdm");
395 	core_pd = pwrdm_lookup("core_pwrdm");
396 	per_pd = pwrdm_lookup("per_pwrdm");
397 	cam_pd = pwrdm_lookup("cam_pwrdm");
398 
399 	if (!mpu_pd || !core_pd || !per_pd || !cam_pd)
400 		return -ENODEV;
401 
402 	if (cpu_is_omap3430())
403 		return cpuidle_register(&omap3430_idle_driver, NULL);
404 	else
405 		return cpuidle_register(&omap3_idle_driver, NULL);
406 }
407