1 /*
2  * Copyright 2012 Calxeda, Inc.
3  *
4  * Based on arch/arm/plat-mxc/cpuidle.c: #v3.7
5  * Copyright 2012 Freescale Semiconductor, Inc.
6  * Copyright 2012 Linaro Ltd.
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms and conditions of the GNU General Public License,
10  * version 2, as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  *
17  * You should have received a copy of the GNU General Public License along with
18  * this program.  If not, see <http://www.gnu.org/licenses/>.
19  *
20  * Maintainer: Rob Herring <rob.herring@calxeda.com>
21  */
22 
23 #include <linux/cpuidle.h>
24 #include <linux/cpu_pm.h>
25 #include <linux/init.h>
26 #include <linux/mm.h>
27 #include <linux/platform_device.h>
28 #include <asm/cpuidle.h>
29 #include <asm/suspend.h>
30 #include <asm/psci.h>
31 
32 static int calxeda_idle_finish(unsigned long val)
33 {
34 	const struct psci_power_state ps = {
35 		.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
36 	};
37 	return psci_ops.cpu_suspend(ps, __pa(cpu_resume));
38 }
39 
40 static int calxeda_pwrdown_idle(struct cpuidle_device *dev,
41 				struct cpuidle_driver *drv,
42 				int index)
43 {
44 	cpu_pm_enter();
45 	cpu_suspend(0, calxeda_idle_finish);
46 	cpu_pm_exit();
47 
48 	return index;
49 }
50 
51 static struct cpuidle_driver calxeda_idle_driver = {
52 	.name = "calxeda_idle",
53 	.states = {
54 		ARM_CPUIDLE_WFI_STATE,
55 		{
56 			.name = "PG",
57 			.desc = "Power Gate",
58 			.flags = CPUIDLE_FLAG_TIME_VALID,
59 			.exit_latency = 30,
60 			.power_usage = 50,
61 			.target_residency = 200,
62 			.enter = calxeda_pwrdown_idle,
63 		},
64 	},
65 	.state_count = 2,
66 };
67 
68 static int __init calxeda_cpuidle_probe(struct platform_device *pdev)
69 {
70 	return cpuidle_register(&calxeda_idle_driver, NULL);
71 }
72 
73 static struct platform_driver calxeda_cpuidle_plat_driver = {
74         .driver = {
75                 .name = "cpuidle-calxeda",
76                 .owner = THIS_MODULE,
77         },
78         .probe = calxeda_cpuidle_probe,
79 };
80 
81 module_platform_driver(calxeda_cpuidle_plat_driver);
82