2 * OMAP4 CPU idle Routines
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 * Santosh Shilimkar <santosh.shilimkar@ti.com>
6 * Rajendra Nayak <rnayak@ti.com>
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.
13 #include <linux/sched.h>
14 #include <linux/cpuidle.h>
15 #include <linux/cpu_pm.h>
16 #include <linux/export.h>
18 #include <asm/proc-fns.h>
23 #include "clockdomain.h"
25 /* Machine specific information */
26 struct omap4_idle_statedata {
32 static struct omap4_idle_statedata omap4_idle_data[] = {
34 .cpu_state = PWRDM_POWER_ON,
35 .mpu_state = PWRDM_POWER_ON,
36 .mpu_logic_state = PWRDM_POWER_RET,
39 .cpu_state = PWRDM_POWER_OFF,
40 .mpu_state = PWRDM_POWER_RET,
41 .mpu_logic_state = PWRDM_POWER_RET,
44 .cpu_state = PWRDM_POWER_OFF,
45 .mpu_state = PWRDM_POWER_RET,
46 .mpu_logic_state = PWRDM_POWER_OFF,
50 static struct powerdomain *mpu_pd, *cpu_pd[NR_CPUS];
51 static struct clockdomain *cpu_clkdm[NR_CPUS];
53 static atomic_t abort_barrier;
54 static bool cpu_done[NR_CPUS];
56 /* Private functions */
59 * omap4_enter_idle_coupled_[simple/coupled] - OMAP4 cpuidle entry functions
60 * @dev: cpuidle device
61 * @drv: cpuidle driver
62 * @index: the index of state to be entered
64 * Called from the CPUidle framework to program the device to the
65 * specified low power state selected by the governor.
66 * Returns the amount of time spent in the low power state.
68 static int omap4_enter_idle_simple(struct cpuidle_device *dev,
69 struct cpuidle_driver *drv,
79 static int omap4_enter_idle_coupled(struct cpuidle_device *dev,
80 struct cpuidle_driver *drv,
83 struct omap4_idle_statedata *cx = &omap4_idle_data[index];
88 * CPU0 has to wait and stay ON until CPU1 is OFF state.
89 * This is necessary to honour hardware recommondation
90 * of triggeing all the possible low power modes once CPU1 is
91 * out of coherency and in OFF mode.
93 if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
94 while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
98 * CPU1 could have already entered & exited idle
99 * without hitting off because of a wakeup
100 * or a failed attempt to hit off mode. Check for
101 * that here, otherwise we could spin forever
102 * waiting for CPU1 off.
111 * Call idle CPU PM enter notifier chain so that
112 * VFP and per CPU interrupt context is saved.
117 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
118 omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
121 * Call idle CPU cluster PM enter notifier chain
122 * to save GIC and wakeupgen context.
124 if ((cx->mpu_state == PWRDM_POWER_RET) &&
125 (cx->mpu_logic_state == PWRDM_POWER_OFF))
126 cpu_cluster_pm_enter();
129 omap4_enter_lowpower(dev->cpu, cx->cpu_state);
130 cpu_done[dev->cpu] = true;
132 /* Wakeup CPU1 only if it is not offlined */
133 if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
134 clkdm_wakeup(cpu_clkdm[1]);
135 clkdm_allow_idle(cpu_clkdm[1]);
139 * Call idle CPU PM exit notifier chain to restore
140 * VFP and per CPU IRQ context.
145 * Call idle CPU cluster PM exit notifier chain
146 * to restore GIC and wakeupgen context.
148 if ((cx->mpu_state == PWRDM_POWER_RET) &&
149 (cx->mpu_logic_state == PWRDM_POWER_OFF))
150 cpu_cluster_pm_exit();
153 cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
154 cpu_done[dev->cpu] = false;
161 static DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);
163 static struct cpuidle_driver omap4_idle_driver = {
164 .name = "omap4_idle",
165 .owner = THIS_MODULE,
166 .en_core_tk_irqen = 1,
169 /* C1 - CPU0 ON + CPU1 ON + MPU ON */
170 .exit_latency = 2 + 2,
171 .target_residency = 5,
172 .flags = CPUIDLE_FLAG_TIME_VALID,
173 .enter = omap4_enter_idle_simple,
175 .desc = "CPUx ON, MPUSS ON"
178 /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
179 .exit_latency = 328 + 440,
180 .target_residency = 960,
181 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED |
182 CPUIDLE_FLAG_TIMER_STOP,
183 .enter = omap4_enter_idle_coupled,
185 .desc = "CPUx OFF, MPUSS CSWR",
188 /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
189 .exit_latency = 460 + 518,
190 .target_residency = 1100,
191 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED |
192 CPUIDLE_FLAG_TIMER_STOP,
193 .enter = omap4_enter_idle_coupled,
195 .desc = "CPUx OFF, MPUSS OSWR",
198 .state_count = ARRAY_SIZE(omap4_idle_data),
199 .safe_state_index = 0,
202 /* Public functions */
205 * omap4_idle_init - Init routine for OMAP4 idle
207 * Registers the OMAP4 specific cpuidle driver to the cpuidle
208 * framework with the valid set of states.
210 int __init omap4_idle_init(void)
212 struct cpuidle_device *dev;
213 unsigned int cpu_id = 0;
215 mpu_pd = pwrdm_lookup("mpu_pwrdm");
216 cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
217 cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
218 if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
221 cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
222 cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
223 if (!cpu_clkdm[0] || !cpu_clkdm[1])
226 if (cpuidle_register_driver(&omap4_idle_driver)) {
227 pr_err("%s: CPUidle driver register failed\n", __func__);
231 for_each_cpu(cpu_id, cpu_online_mask) {
232 dev = &per_cpu(omap4_idle_dev, cpu_id);
234 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
235 dev->coupled_cpus = *cpu_online_mask;
237 if (cpuidle_register_device(dev)) {
238 pr_err("%s: CPUidle register failed\n", __func__);
239 cpuidle_unregister_driver(&omap4_idle_driver);