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 <linux/psci.h>
  29
  30 #include <asm/cpuidle.h>
  31 #include <asm/suspend.h>
  32
  33 #include <uapi/linux/psci.h>
  34
  35 #define CALXEDA_IDLE_PARAM \
  36         ((0 << PSCI_0_2_POWER_STATE_ID_SHIFT) | \
  37          (0 << PSCI_0_2_POWER_STATE_AFFL_SHIFT) | \
  38          (PSCI_POWER_STATE_TYPE_POWER_DOWN << PSCI_0_2_POWER_STATE_TYPE_SHIFT))
  39
  40 static int calxeda_idle_finish(unsigned long val)
  41 {
  42         return psci_ops.cpu_suspend(CALXEDA_IDLE_PARAM, __pa(cpu_resume));
  43 }
  44
  45 static int calxeda_pwrdown_idle(struct cpuidle_device *dev,
  46                                 struct cpuidle_driver *drv,
  47                                 int index)
  48 {
  49         cpu_pm_enter();
  50         cpu_suspend(0, calxeda_idle_finish);
  51         cpu_pm_exit();
  52
  53         return index;
  54 }
  55
  56 static struct cpuidle_driver calxeda_idle_driver = {
  57         .name = "calxeda_idle",
  58         .states = {
  59                 ARM_CPUIDLE_WFI_STATE,
  60                 {
  61                         .name = "PG",
  62                         .desc = "Power Gate",
  63                         .exit_latency = 30,
  64                         .power_usage = 50,
  65                         .target_residency = 200,
  66                         .enter = calxeda_pwrdown_idle,
  67                 },
  68         },
  69         .state_count = 2,
  70 };
  71
  72 static int calxeda_cpuidle_probe(struct platform_device *pdev)
  73 {
  74         return cpuidle_register(&calxeda_idle_driver, NULL);
  75 }
  76
  77 static struct platform_driver calxeda_cpuidle_plat_driver = {
  78         .driver = {
  79                 .name = "cpuidle-calxeda",
  80         },
  81         .probe = calxeda_cpuidle_probe,
  82 };
  83 builtin_platform_driver(calxeda_cpuidle_plat_driver);