drivers/cpuidle/cpuidle-calxeda.c

   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);