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[~andy/linux] / arch / arm / mach-omap2 / cpuidle44xx.c
1 /*
2  * OMAP4 CPU idle Routines
3  *
4  * Copyright (C) 2011 Texas Instruments, Inc.
5  * Santosh Shilimkar <santosh.shilimkar@ti.com>
6  * Rajendra Nayak <rnayak@ti.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12
13 #include <linux/sched.h>
14 #include <linux/cpuidle.h>
15 #include <linux/cpu_pm.h>
16 #include <linux/export.h>
17 #include <linux/clockchips.h>
18
19 #include <asm/proc-fns.h>
20
21 #include "common.h"
22 #include "pm.h"
23 #include "prm.h"
24
25 #ifdef CONFIG_CPU_IDLE
26
27 /* Machine specific information to be recorded in the C-state driver_data */
28 struct omap4_idle_statedata {
29         u32 cpu_state;
30         u32 mpu_logic_state;
31         u32 mpu_state;
32         u8 valid;
33 };
34
35 static struct cpuidle_params cpuidle_params_table[] = {
36         /* C1 - CPU0 ON + CPU1 ON + MPU ON */
37         {.exit_latency = 2 + 2 , .target_residency = 5, .valid = 1},
38         /* C2- CPU0 OFF + CPU1 OFF + MPU CSWR */
39         {.exit_latency = 328 + 440 , .target_residency = 960, .valid = 1},
40         /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
41         {.exit_latency = 460 + 518 , .target_residency = 1100, .valid = 1},
42 };
43
44 #define OMAP4_NUM_STATES ARRAY_SIZE(cpuidle_params_table)
45
46 struct omap4_idle_statedata omap4_idle_data[OMAP4_NUM_STATES];
47 static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd;
48
49 /**
50  * omap4_enter_idle - Programs OMAP4 to enter the specified state
51  * @dev: cpuidle device
52  * @drv: cpuidle driver
53  * @index: the index of state to be entered
54  *
55  * Called from the CPUidle framework to program the device to the
56  * specified low power state selected by the governor.
57  * Returns the amount of time spent in the low power state.
58  */
59 static int omap4_enter_idle(struct cpuidle_device *dev,
60                         struct cpuidle_driver *drv,
61                         int index)
62 {
63         struct omap4_idle_statedata *cx =
64                         cpuidle_get_statedata(&dev->states_usage[index]);
65         u32 cpu1_state;
66         int cpu_id = smp_processor_id();
67
68         local_fiq_disable();
69
70         /*
71          * CPU0 has to stay ON (i.e in C1) until CPU1 is OFF state.
72          * This is necessary to honour hardware recommondation
73          * of triggeing all the possible low power modes once CPU1 is
74          * out of coherency and in OFF mode.
75          * Update dev->last_state so that governor stats reflects right
76          * data.
77          */
78         cpu1_state = pwrdm_read_pwrst(cpu1_pd);
79         if (cpu1_state != PWRDM_POWER_OFF) {
80                 index = drv->safe_state_index;
81                 cx = cpuidle_get_statedata(&dev->states_usage[index]);
82         }
83
84         if (index > 0)
85                 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id);
86
87         /*
88          * Call idle CPU PM enter notifier chain so that
89          * VFP and per CPU interrupt context is saved.
90          */
91         if (cx->cpu_state == PWRDM_POWER_OFF)
92                 cpu_pm_enter();
93
94         pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
95         omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
96
97         /*
98          * Call idle CPU cluster PM enter notifier chain
99          * to save GIC and wakeupgen context.
100          */
101         if ((cx->mpu_state == PWRDM_POWER_RET) &&
102                 (cx->mpu_logic_state == PWRDM_POWER_OFF))
103                         cpu_cluster_pm_enter();
104
105         omap4_enter_lowpower(dev->cpu, cx->cpu_state);
106
107         /*
108          * Call idle CPU PM exit notifier chain to restore
109          * VFP and per CPU IRQ context. Only CPU0 state is
110          * considered since CPU1 is managed by CPU hotplug.
111          */
112         if (pwrdm_read_prev_pwrst(cpu0_pd) == PWRDM_POWER_OFF)
113                 cpu_pm_exit();
114
115         /*
116          * Call idle CPU cluster PM exit notifier chain
117          * to restore GIC and wakeupgen context.
118          */
119         if (omap4_mpuss_read_prev_context_state())
120                 cpu_cluster_pm_exit();
121
122         if (index > 0)
123                 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);
124
125         local_fiq_enable();
126
127         return index;
128 }
129
130 DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);
131
132 struct cpuidle_driver omap4_idle_driver = {
133         .name                           = "omap4_idle",
134         .owner                          = THIS_MODULE,
135         .en_core_tk_irqen               = 1,
136 };
137
138 static inline void _fill_cstate(struct cpuidle_driver *drv,
139                                         int idx, const char *descr)
140 {
141         struct cpuidle_state *state = &drv->states[idx];
142
143         state->exit_latency     = cpuidle_params_table[idx].exit_latency;
144         state->target_residency = cpuidle_params_table[idx].target_residency;
145         state->flags            = CPUIDLE_FLAG_TIME_VALID;
146         state->enter            = omap4_enter_idle;
147         sprintf(state->name, "C%d", idx + 1);
148         strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
149 }
150
151 static inline struct omap4_idle_statedata *_fill_cstate_usage(
152                                         struct cpuidle_device *dev,
153                                         int idx)
154 {
155         struct omap4_idle_statedata *cx = &omap4_idle_data[idx];
156         struct cpuidle_state_usage *state_usage = &dev->states_usage[idx];
157
158         cx->valid               = cpuidle_params_table[idx].valid;
159         cpuidle_set_statedata(state_usage, cx);
160
161         return cx;
162 }
163
164
165
166 /**
167  * omap4_idle_init - Init routine for OMAP4 idle
168  *
169  * Registers the OMAP4 specific cpuidle driver to the cpuidle
170  * framework with the valid set of states.
171  */
172 int __init omap4_idle_init(void)
173 {
174         struct omap4_idle_statedata *cx;
175         struct cpuidle_device *dev;
176         struct cpuidle_driver *drv = &omap4_idle_driver;
177         unsigned int cpu_id = 0;
178
179         mpu_pd = pwrdm_lookup("mpu_pwrdm");
180         cpu0_pd = pwrdm_lookup("cpu0_pwrdm");
181         cpu1_pd = pwrdm_lookup("cpu1_pwrdm");
182         if ((!mpu_pd) || (!cpu0_pd) || (!cpu1_pd))
183                 return -ENODEV;
184
185
186         drv->safe_state_index = -1;
187         dev = &per_cpu(omap4_idle_dev, cpu_id);
188         dev->cpu = cpu_id;
189
190         /* C1 - CPU0 ON + CPU1 ON + MPU ON */
191         _fill_cstate(drv, 0, "MPUSS ON");
192         drv->safe_state_index = 0;
193         cx = _fill_cstate_usage(dev, 0);
194         cx->valid = 1;  /* C1 is always valid */
195         cx->cpu_state = PWRDM_POWER_ON;
196         cx->mpu_state = PWRDM_POWER_ON;
197         cx->mpu_logic_state = PWRDM_POWER_RET;
198
199         /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
200         _fill_cstate(drv, 1, "MPUSS CSWR");
201         cx = _fill_cstate_usage(dev, 1);
202         cx->cpu_state = PWRDM_POWER_OFF;
203         cx->mpu_state = PWRDM_POWER_RET;
204         cx->mpu_logic_state = PWRDM_POWER_RET;
205
206         /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
207         _fill_cstate(drv, 2, "MPUSS OSWR");
208         cx = _fill_cstate_usage(dev, 2);
209         cx->cpu_state = PWRDM_POWER_OFF;
210         cx->mpu_state = PWRDM_POWER_RET;
211         cx->mpu_logic_state = PWRDM_POWER_OFF;
212
213         drv->state_count = OMAP4_NUM_STATES;
214         cpuidle_register_driver(&omap4_idle_driver);
215
216         dev->state_count = OMAP4_NUM_STATES;
217         if (cpuidle_register_device(dev)) {
218                 pr_err("%s: CPUidle register device failed\n", __func__);
219                         return -EIO;
220                 }
221
222         return 0;
223 }
224 #else
225 int __init omap4_idle_init(void)
226 {
227         return 0;
228 }
229 #endif /* CONFIG_CPU_IDLE */