aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mach-omap2/cpuidle44xx.c
blob: 9de47a70628f0e15a3ee49a47cb6c2be6a73d050 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
/*
 * OMAP4 CPU idle Routines
 *
 * Copyright (C) 2011 Texas Instruments, Inc.
 * Santosh Shilimkar <santosh.shilimkar@ti.com>
 * Rajendra Nayak <rnayak@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/sched.h>
#include <linux/cpuidle.h>
#include <linux/cpu_pm.h>
#include <linux/export.h>
#include <linux/clockchips.h>

#include <asm/proc-fns.h>

#include "common.h"
#include "pm.h"
#include "prm.h"
#include "clockdomain.h"

/* Machine specific information */
struct omap4_idle_statedata {
	u32 cpu_state;
	u32 mpu_logic_state;
	u32 mpu_state;
};

static struct omap4_idle_statedata omap4_idle_data[] = {
	{
		.cpu_state = PWRDM_POWER_ON,
		.mpu_state = PWRDM_POWER_ON,
		.mpu_logic_state = PWRDM_POWER_RET,
	},
	{
		.cpu_state = PWRDM_POWER_OFF,
		.mpu_state = PWRDM_POWER_RET,
		.mpu_logic_state = PWRDM_POWER_RET,
	},
	{
		.cpu_state = PWRDM_POWER_OFF,
		.mpu_state = PWRDM_POWER_RET,
		.mpu_logic_state = PWRDM_POWER_OFF,
	},
};

static struct powerdomain *mpu_pd, *cpu_pd[NR_CPUS];
static struct clockdomain *cpu_clkdm[NR_CPUS];

static atomic_t abort_barrier;
static bool cpu_done[NR_CPUS];

/* Private functions */

/**
 * omap4_enter_idle_coupled_[simple/coupled] - OMAP4 cpuidle entry functions
 * @dev: cpuidle device
 * @drv: cpuidle driver
 * @index: the index of state to be entered
 *
 * Called from the CPUidle framework to program the device to the
 * specified low power state selected by the governor.
 * Returns the amount of time spent in the low power state.
 */
static int omap4_enter_idle_simple(struct cpuidle_device *dev,
			struct cpuidle_driver *drv,
			int index)
{
	omap_do_wfi();
	return index;
}

static int omap4_enter_idle_coupled(struct cpuidle_device *dev,
			struct cpuidle_driver *drv,
			int index)
{
	struct omap4_idle_statedata *cx = &omap4_idle_data[index];
	int cpu_id = smp_processor_id();

	/*
	 * CPU0 has to wait and stay ON until CPU1 is OFF state.
	 * This is necessary to honour hardware recommondation
	 * of triggeing all the possible low power modes once CPU1 is
	 * out of coherency and in OFF mode.
	 */
	if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
		while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
			cpu_relax();

			/*
			 * CPU1 could have already entered & exited idle
			 * without hitting off because of a wakeup
			 * or a failed attempt to hit off mode.  Check for
			 * that here, otherwise we could spin forever
			 * waiting for CPU1 off.
			 */
			if (cpu_done[1])
			    goto fail;

		}
	}

	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id);

	/*
	 * Call idle CPU PM enter notifier chain so that
	 * VFP and per CPU interrupt context is saved.
	 */
	cpu_pm_enter();

	if (dev->cpu == 0) {
		pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
		omap_set_pwrdm_state(mpu_pd, cx->mpu_state);

		/*
		 * Call idle CPU cluster PM enter notifier chain
		 * to save GIC and wakeupgen context.
		 */
		if ((cx->mpu_state == PWRDM_POWER_RET) &&
			(cx->mpu_logic_state == PWRDM_POWER_OFF))
				cpu_cluster_pm_enter();
	}

	omap4_enter_lowpower(dev->cpu, cx->cpu_state);
	cpu_done[dev->cpu] = true;

	/* Wakeup CPU1 only if it is not offlined */
	if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
		clkdm_wakeup(cpu_clkdm[1]);
		omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON);
		clkdm_allow_idle(cpu_clkdm[1]);
	}

	/*
	 * Call idle CPU PM exit notifier chain to restore
	 * VFP and per CPU IRQ context.
	 */
	cpu_pm_exit();

	/*
	 * Call idle CPU cluster PM exit notifier chain
	 * to restore GIC and wakeupgen context.
	 */
	if (omap4_mpuss_read_prev_context_state())
		cpu_cluster_pm_exit();

	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);

fail:
	cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
	cpu_done[dev->cpu] = false;

	return index;
}

/*
 * For each cpu, setup the broadcast timer because local timers
 * stops for the states above C1.
 */
static void omap_setup_broadcast_timer(void *arg)
{
	int cpu = smp_processor_id();
	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &cpu);
}

static DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);

static struct cpuidle_driver omap4_idle_driver = {
	.name				= "omap4_idle",
	.owner				= THIS_MODULE,
	.en_core_tk_irqen		= 1,
	.states = {
		{
			/* C1 - CPU0 ON + CPU1 ON + MPU ON */
			.exit_latency = 2 + 2,
			.target_residency = 5,
			.flags = CPUIDLE_FLAG_TIME_VALID,
			.enter = omap4_enter_idle_simple,
			.name = "C1",
			.desc = "MPUSS ON"
		},
		{
			/* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
			.exit_latency = 328 + 440,
			.target_residency = 960,
			.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
			.enter = omap4_enter_idle_coupled,
			.name = "C2",
			.desc = "MPUSS CSWR",
		},
		{
			/* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
			.exit_latency = 460 + 518,
			.target_residency = 1100,
			.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
			.enter = omap4_enter_idle_coupled,
			.name = "C3",
			.desc = "MPUSS OSWR",
		},
	},
	.state_count = ARRAY_SIZE(omap4_idle_data),
	.safe_state_index = 0,
};

/* Public functions */

/**
 * omap4_idle_init - Init routine for OMAP4 idle
 *
 * Registers the OMAP4 specific cpuidle driver to the cpuidle
 * framework with the valid set of states.
 */
int __init omap4_idle_init(void)
{
	struct cpuidle_device *dev;
	unsigned int cpu_id = 0;

	mpu_pd = pwrdm_lookup("mpu_pwrdm");
	cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
	cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
	if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
		return -ENODEV;

	cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
	cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
	if (!cpu_clkdm[0] || !cpu_clkdm[1])
		return -ENODEV;

	/* Configure the broadcast timer on each cpu */
	on_each_cpu(omap_setup_broadcast_timer, NULL, 1);

	for_each_cpu(cpu_id, cpu_online_mask) {
		dev = &per_cpu(omap4_idle_dev, cpu_id);
		dev->cpu = cpu_id;
#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
		dev->coupled_cpus = *cpu_online_mask;
#endif
		cpuidle_register_driver(&omap4_idle_driver);

		if (cpuidle_register_device(dev)) {
			pr_err("%s: CPUidle register failed\n", __func__);
			return -EIO;
		}
	}

	return 0;
}