1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * OMAP4+ CPU idle Routines
4 *
5 * Copyright (C) 2011-2013 Texas Instruments, Inc.
6 * Santosh Shilimkar <santosh.shilimkar@ti.com>
7 * Rajendra Nayak <rnayak@ti.com>
8 */
9
10 #include <linux/sched.h>
11 #include <linux/cpuidle.h>
12 #include <linux/cpu_pm.h>
13 #include <linux/export.h>
14 #include <linux/tick.h>
15
16 #include <asm/cpuidle.h>
17
18 #include "common.h"
19 #include "pm.h"
20 #include "prm.h"
21 #include "soc.h"
22 #include "clockdomain.h"
23
24 #define MAX_CPUS 2
25
26 /* Machine specific information */
27 struct idle_statedata {
28 u32 cpu_state;
29 u32 mpu_logic_state;
30 u32 mpu_state;
31 u32 mpu_state_vote;
32 };
33
34 static struct idle_statedata omap4_idle_data[] = {
35 {
36 .cpu_state = PWRDM_POWER_ON,
37 .mpu_state = PWRDM_POWER_ON,
38 .mpu_logic_state = PWRDM_POWER_RET,
39 },
40 {
41 .cpu_state = PWRDM_POWER_OFF,
42 .mpu_state = PWRDM_POWER_RET,
43 .mpu_logic_state = PWRDM_POWER_RET,
44 },
45 {
46 .cpu_state = PWRDM_POWER_OFF,
47 .mpu_state = PWRDM_POWER_RET,
48 .mpu_logic_state = PWRDM_POWER_OFF,
49 },
50 };
51
52 static struct idle_statedata omap5_idle_data[] = {
53 {
54 .cpu_state = PWRDM_POWER_ON,
55 .mpu_state = PWRDM_POWER_ON,
56 .mpu_logic_state = PWRDM_POWER_ON,
57 },
58 {
59 .cpu_state = PWRDM_POWER_RET,
60 .mpu_state = PWRDM_POWER_RET,
61 .mpu_logic_state = PWRDM_POWER_RET,
62 },
63 };
64
65 static struct powerdomain *mpu_pd, *cpu_pd[MAX_CPUS];
66 static struct clockdomain *cpu_clkdm[MAX_CPUS];
67
68 static atomic_t abort_barrier;
69 static bool cpu_done[MAX_CPUS];
70 static struct idle_statedata *state_ptr = &omap4_idle_data[0];
71 static DEFINE_RAW_SPINLOCK(mpu_lock);
72
73 /* Private functions */
74
75 /**
76 * omap_enter_idle_[simple/coupled] - OMAP4PLUS cpuidle entry functions
77 * @dev: cpuidle device
78 * @drv: cpuidle driver
79 * @index: the index of state to be entered
80 *
81 * Called from the CPUidle framework to program the device to the
82 * specified low power state selected by the governor.
83 * Returns the amount of time spent in the low power state.
84 */
85 static int omap_enter_idle_simple(struct cpuidle_device *dev,
86 struct cpuidle_driver *drv,
87 int index)
88 {
89 omap_do_wfi();
90 return index;
91 }
92
93 static int omap_enter_idle_smp(struct cpuidle_device *dev,
94 struct cpuidle_driver *drv,
95 int index)
96 {
97 struct idle_statedata *cx = state_ptr + index;
98 unsigned long flag;
99
100 raw_spin_lock_irqsave(&mpu_lock, flag);
101 cx->mpu_state_vote++;
102 if (cx->mpu_state_vote == num_online_cpus()) {
103 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
104 omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
105 }
106 raw_spin_unlock_irqrestore(&mpu_lock, flag);
107
108 omap4_enter_lowpower(dev->cpu, cx->cpu_state, true);
109
110 raw_spin_lock_irqsave(&mpu_lock, flag);
111 if (cx->mpu_state_vote == num_online_cpus())
112 omap_set_pwrdm_state(mpu_pd, PWRDM_POWER_ON);
113 cx->mpu_state_vote--;
114 raw_spin_unlock_irqrestore(&mpu_lock, flag);
115
116 return index;
117 }
118
119 static int omap_enter_idle_coupled(struct cpuidle_device *dev,
120 struct cpuidle_driver *drv,
121 int index)
122 {
123 struct idle_statedata *cx = state_ptr + index;
124 u32 mpuss_can_lose_context = 0;
125 int error;
126
127 /*
128 * CPU0 has to wait and stay ON until CPU1 is OFF state.
129 * This is necessary to honour hardware recommondation
130 * of triggeing all the possible low power modes once CPU1 is
131 * out of coherency and in OFF mode.
132 */
133 if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
134 while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
135 cpu_relax();
136
137 /*
138 * CPU1 could have already entered & exited idle
139 * without hitting off because of a wakeup
140 * or a failed attempt to hit off mode. Check for
141 * that here, otherwise we could spin forever
142 * waiting for CPU1 off.
143 */
144 if (cpu_done[1])
145 goto fail;
146
147 }
148 }
149
150 mpuss_can_lose_context = (cx->mpu_state == PWRDM_POWER_RET) &&
151 (cx->mpu_logic_state == PWRDM_POWER_OFF);
152
153 /* Enter broadcast mode for periodic timers */
154 tick_broadcast_enable();
155
156 /* Enter broadcast mode for one-shot timers */
157 tick_broadcast_enter();
158
159 /*
160 * Call idle CPU PM enter notifier chain so that
161 * VFP and per CPU interrupt context is saved.
162 */
163 error = cpu_pm_enter();
164 if (error)
165 goto cpu_pm_out;
166
167 if (dev->cpu == 0) {
168 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
169 omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
170
171 /*
172 * Call idle CPU cluster PM enter notifier chain
173 * to save GIC and wakeupgen context.
174 */
175 if (mpuss_can_lose_context) {
176 error = cpu_cluster_pm_enter();
177 if (error) {
178 index = 0;
179 cx = state_ptr + index;
180 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
181 omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
182 mpuss_can_lose_context = 0;
183 }
184 }
185 }
186
187 omap4_enter_lowpower(dev->cpu, cx->cpu_state, true);
188 cpu_done[dev->cpu] = true;
189
190 /* Wakeup CPU1 only if it is not offlined */
191 if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
192
193 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) &&
194 mpuss_can_lose_context)
195 gic_dist_disable();
196
197 clkdm_deny_idle(cpu_clkdm[1]);
198 omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON);
199 clkdm_allow_idle(cpu_clkdm[1]);
200
201 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) &&
202 mpuss_can_lose_context) {
203 while (gic_dist_disabled()) {
204 udelay(1);
205 cpu_relax();
206 }
207 gic_timer_retrigger();
208 }
209 }
210
211 /*
212 * Call idle CPU cluster PM exit notifier chain
213 * to restore GIC and wakeupgen context.
214 */
215 if (dev->cpu == 0 && mpuss_can_lose_context)
216 cpu_cluster_pm_exit();
217
218 /*
219 * Call idle CPU PM exit notifier chain to restore
220 * VFP and per CPU IRQ context.
221 */
222 cpu_pm_exit();
223
224 cpu_pm_out:
225 tick_broadcast_exit();
226
227 fail:
228 cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
229 cpu_done[dev->cpu] = false;
230
231 return index;
232 }
233
234 static struct cpuidle_driver omap4_idle_driver = {
235 .name = "omap4_idle",
236 .owner = THIS_MODULE,
237 .states = {
238 {
239 /* C1 - CPU0 ON + CPU1 ON + MPU ON */
240 .exit_latency = 2 + 2,
241 .target_residency = 5,
242 .enter = omap_enter_idle_simple,
243 .name = "C1",
244 .desc = "CPUx ON, MPUSS ON"
245 },
246 {
247 /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
248 .exit_latency = 328 + 440,
249 .target_residency = 960,
250 .flags = CPUIDLE_FLAG_COUPLED |
251 CPUIDLE_FLAG_RCU_IDLE,
252 .enter = omap_enter_idle_coupled,
253 .name = "C2",
254 .desc = "CPUx OFF, MPUSS CSWR",
255 },
256 {
257 /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
258 .exit_latency = 460 + 518,
259 .target_residency = 1100,
260 .flags = CPUIDLE_FLAG_COUPLED |
261 CPUIDLE_FLAG_RCU_IDLE,
262 .enter = omap_enter_idle_coupled,
263 .name = "C3",
264 .desc = "CPUx OFF, MPUSS OSWR",
265 },
266 },
267 .state_count = ARRAY_SIZE(omap4_idle_data),
268 .safe_state_index = 0,
269 };
270
271 static struct cpuidle_driver omap5_idle_driver = {
272 .name = "omap5_idle",
273 .owner = THIS_MODULE,
274 .states = {
275 {
276 /* C1 - CPU0 ON + CPU1 ON + MPU ON */
277 .exit_latency = 2 + 2,
278 .target_residency = 5,
279 .enter = omap_enter_idle_simple,
280 .name = "C1",
281 .desc = "CPUx WFI, MPUSS ON"
282 },
283 {
284 /* C2 - CPU0 RET + CPU1 RET + MPU CSWR */
285 .exit_latency = 48 + 60,
286 .target_residency = 100,
287 .flags = CPUIDLE_FLAG_TIMER_STOP |
288 CPUIDLE_FLAG_RCU_IDLE,
289 .enter = omap_enter_idle_smp,
290 .name = "C2",
291 .desc = "CPUx CSWR, MPUSS CSWR",
292 },
293 },
294 .state_count = ARRAY_SIZE(omap5_idle_data),
295 .safe_state_index = 0,
296 };
297
298 /* Public functions */
299
300 /**
301 * omap4_idle_init - Init routine for OMAP4+ idle
302 *
303 * Registers the OMAP4+ specific cpuidle driver to the cpuidle
304 * framework with the valid set of states.
305 */
306 int __init omap4_idle_init(void)
307 {
308 struct cpuidle_driver *idle_driver;
309
310 if (soc_is_omap54xx()) {
311 state_ptr = &omap5_idle_data[0];
312 idle_driver = &omap5_idle_driver;
313 } else {
314 state_ptr = &omap4_idle_data[0];
315 idle_driver = &omap4_idle_driver;
316 }
317
318 mpu_pd = pwrdm_lookup("mpu_pwrdm");
319 cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
320 cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
321 if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
322 return -ENODEV;
323
324 cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
325 cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
326 if (!cpu_clkdm[0] || !cpu_clkdm[1])
327 return -ENODEV;
328
329 return cpuidle_register(idle_driver, cpu_online_mask);
330 }
331
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