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>
17 #include <linux/clockchips.h>
19 #include <asm/proc-fns.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
, *cpu0_pd
, *cpu1_pd
;
53 * omap4_enter_idle - Programs OMAP4 to enter the specified state
54 * @dev: cpuidle device
55 * @drv: cpuidle driver
56 * @index: the index of state to be entered
58 * Called from the CPUidle framework to program the device to the
59 * specified low power state selected by the governor.
60 * Returns the amount of time spent in the low power state.
62 static int omap4_enter_idle(struct cpuidle_device
*dev
,
63 struct cpuidle_driver
*drv
,
66 struct omap4_idle_statedata
*cx
= &omap4_idle_data
[index
];
68 int cpu_id
= smp_processor_id();
73 * CPU0 has to stay ON (i.e in C1) until CPU1 is OFF state.
74 * This is necessary to honour hardware recommondation
75 * of triggeing all the possible low power modes once CPU1 is
76 * out of coherency and in OFF mode.
77 * Update dev->last_state so that governor stats reflects right
80 cpu1_state
= pwrdm_read_pwrst(cpu1_pd
);
81 if (cpu1_state
!= PWRDM_POWER_OFF
) {
82 index
= drv
->safe_state_index
;
83 cx
= &omap4_idle_data
[index
];
87 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER
, &cpu_id
);
90 * Call idle CPU PM enter notifier chain so that
91 * VFP and per CPU interrupt context is saved.
93 if (cx
->cpu_state
== PWRDM_POWER_OFF
)
96 pwrdm_set_logic_retst(mpu_pd
, cx
->mpu_logic_state
);
97 omap_set_pwrdm_state(mpu_pd
, cx
->mpu_state
);
100 * Call idle CPU cluster PM enter notifier chain
101 * to save GIC and wakeupgen context.
103 if ((cx
->mpu_state
== PWRDM_POWER_RET
) &&
104 (cx
->mpu_logic_state
== PWRDM_POWER_OFF
))
105 cpu_cluster_pm_enter();
107 omap4_enter_lowpower(dev
->cpu
, cx
->cpu_state
);
110 * Call idle CPU PM exit notifier chain to restore
111 * VFP and per CPU IRQ context. Only CPU0 state is
112 * considered since CPU1 is managed by CPU hotplug.
114 if (pwrdm_read_prev_pwrst(cpu0_pd
) == PWRDM_POWER_OFF
)
118 * Call idle CPU cluster PM exit notifier chain
119 * to restore GIC and wakeupgen context.
121 if (omap4_mpuss_read_prev_context_state())
122 cpu_cluster_pm_exit();
125 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT
, &cpu_id
);
132 DEFINE_PER_CPU(struct cpuidle_device
, omap4_idle_dev
);
134 struct cpuidle_driver omap4_idle_driver
= {
135 .name
= "omap4_idle",
136 .owner
= THIS_MODULE
,
137 .en_core_tk_irqen
= 1,
140 /* C1 - CPU0 ON + CPU1 ON + MPU ON */
141 .exit_latency
= 2 + 2,
142 .target_residency
= 5,
143 .flags
= CPUIDLE_FLAG_TIME_VALID
,
144 .enter
= omap4_enter_idle
,
149 /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
150 .exit_latency
= 328 + 440,
151 .target_residency
= 960,
152 .flags
= CPUIDLE_FLAG_TIME_VALID
,
153 .enter
= omap4_enter_idle
,
155 .desc
= "MPUSS CSWR",
158 /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
159 .exit_latency
= 460 + 518,
160 .target_residency
= 1100,
161 .flags
= CPUIDLE_FLAG_TIME_VALID
,
162 .enter
= omap4_enter_idle
,
164 .desc
= "MPUSS OSWR",
167 .state_count
= ARRAY_SIZE(omap4_idle_data
),
168 .safe_state_index
= 0,
172 * omap4_idle_init - Init routine for OMAP4 idle
174 * Registers the OMAP4 specific cpuidle driver to the cpuidle
175 * framework with the valid set of states.
177 int __init
omap4_idle_init(void)
179 struct cpuidle_device
*dev
;
180 unsigned int cpu_id
= 0;
182 mpu_pd
= pwrdm_lookup("mpu_pwrdm");
183 cpu0_pd
= pwrdm_lookup("cpu0_pwrdm");
184 cpu1_pd
= pwrdm_lookup("cpu1_pwrdm");
185 if ((!mpu_pd
) || (!cpu0_pd
) || (!cpu1_pd
))
188 dev
= &per_cpu(omap4_idle_dev
, cpu_id
);
191 cpuidle_register_driver(&omap4_idle_driver
);
193 if (cpuidle_register_device(dev
)) {
194 pr_err("%s: CPUidle register device failed\n", __func__
);