drivers/cpuidle/cpuidle-calxeda.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2012 Calxeda, Inc.
   4  *
   5  * Based on arch/arm/plat-mxc/cpuidle.c: #v3.7
   6  * Copyright 2012 Freescale Semiconductor, Inc.
   7  * Copyright 2012 Linaro Ltd.
   8  *
   9  * Maintainer: Rob Herring <rob.herring@calxeda.com>
  10  */
  11
  12 #include <linux/cpuidle.h>
  13 #include <linux/cpu_pm.h>
  14 #include <linux/init.h>
  15 #include <linux/mm.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/psci.h>
  18
  19 #include <asm/cpuidle.h>
  20 #include <asm/suspend.h>
  21
  22 #include <uapi/linux/psci.h>
  23
  24 #define CALXEDA_IDLE_PARAM \
  25         ((0 << PSCI_0_2_POWER_STATE_ID_SHIFT) | \
  26          (0 << PSCI_0_2_POWER_STATE_AFFL_SHIFT) | \
  27          (PSCI_POWER_STATE_TYPE_POWER_DOWN << PSCI_0_2_POWER_STATE_TYPE_SHIFT))
  28
  29 static int calxeda_idle_finish(unsigned long val)
  30 {
  31         return psci_ops.cpu_suspend(CALXEDA_IDLE_PARAM, __pa(cpu_resume));
  32 }
  33
  34 static int calxeda_pwrdown_idle(struct cpuidle_device *dev,
  35                                 struct cpuidle_driver *drv,
  36                                 int index)
  37 {
  38         cpu_pm_enter();
  39         cpu_suspend(0, calxeda_idle_finish);
  40         cpu_pm_exit();
  41
  42         return index;
  43 }
  44
  45 static struct cpuidle_driver calxeda_idle_driver = {
  46         .name = "calxeda_idle",
  47         .states = {
  48                 ARM_CPUIDLE_WFI_STATE,
  49                 {
  50                         .name = "PG",
  51                         .desc = "Power Gate",
  52                         .exit_latency = 30,
  53                         .power_usage = 50,
  54                         .target_residency = 200,
  55                         .enter = calxeda_pwrdown_idle,
  56                 },
  57         },
  58         .state_count = 2,
  59 };
  60
  61 static int calxeda_cpuidle_probe(struct platform_device *pdev)
  62 {
  63         return cpuidle_register(&calxeda_idle_driver, NULL);
  64 }
  65
  66 static struct platform_driver calxeda_cpuidle_plat_driver = {
  67         .driver = {
  68                 .name = "cpuidle-calxeda",
  69         },
  70         .probe = calxeda_cpuidle_probe,
  71 };
  72 builtin_platform_driver(calxeda_cpuidle_plat_driver);