text: /*
   * CPU idle driver for Tegra CPUs
   *
   * Copyright (c) 2010-2012, NVIDIA Corporation.
   * Copyright (c) 2011 Google, Inc.
   * Author: Colin Cross <ccross@android.com>
   *         Gary King <gking@nvidia.com>
   *
   * Rework for 3.3 by Peter De Schrijver <pdeschrijver@nvidia.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   */
  
  #include <linux/clk/tegra.h>
  #include <linux/clockchips.h>
  #include <linux/cpuidle.h>
  #include <linux/cpu_pm.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  
  #include <asm/cpuidle.h>
  #include <asm/proc-fns.h>
  #include <asm/smp_plat.h>
  #include <asm/suspend.h>
  
  #include "pm.h"
  #include "sleep.h"
  
  #ifdef CONFIG_PM_SLEEP
  static int tegra30_idle_lp2(struct cpuidle_device *dev,
  			    struct cpuidle_driver *drv,
  			    int index);
  #endif
  
  static struct cpuidle_driver tegra_idle_driver = {
  	.name = "tegra_idle",
  	.owner = THIS_MODULE,
  #ifdef CONFIG_PM_SLEEP
  	.state_count = 2,
  #else
  	.state_count = 1,
  #endif
  	.states = {
  		[0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
  #ifdef CONFIG_PM_SLEEP
  		[1] = {
  			.enter			= tegra30_idle_lp2,
  			.exit_latency		= 2000,
  			.target_residency	= 2200,
  			.power_usage		= 0,
  			.flags			= CPUIDLE_FLAG_TIME_VALID,
  			.name			= "powered-down",
  			.desc			= "CPU power gated",
  		},
  #endif
  	},
  };
  
  #ifdef CONFIG_PM_SLEEP
  static bool tegra30_cpu_cluster_power_down(struct cpuidle_device *dev,
  					   struct cpuidle_driver *drv,
  					   int index)
  {
  	/* All CPUs entering LP2 is not working.
  	 * Don't let CPU0 enter LP2 when any secondary CPU is online.
  	 */
  	if (num_online_cpus() > 1 || !tegra_cpu_rail_off_ready()) {
  		cpu_do_idle();
  		return false;
  	}
  
  	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
  
  	tegra_idle_lp2_last();
  
  	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
  
  	return true;
  }
  
  #ifdef CONFIG_SMP
  static bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
  					struct cpuidle_driver *drv,
  					int index)
  {
  	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
  
  	smp_wmb();
  
  	cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
  
  	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
  
  	return true;
  }
  #else
  static inline bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
  					       struct cpuidle_driver *drv,
  					       int index)
  {
  	return true;
  }
  #endif
  
  static int tegra30_idle_lp2(struct cpuidle_device *dev,
  			    struct cpuidle_driver *drv,
  			    int index)
  {
  	bool entered_lp2 = false;
  	bool last_cpu;
  
  	local_fiq_disable();
  
  	last_cpu = tegra_set_cpu_in_lp2();
  	cpu_pm_enter();
  
  	if (dev->cpu == 0) {
  		if (last_cpu)
  			entered_lp2 = tegra30_cpu_cluster_power_down(dev, drv,
  								     index);
  		else
  			cpu_do_idle();
  	} else {
  		entered_lp2 = tegra30_cpu_core_power_down(dev, drv, index);
  	}
  
  	cpu_pm_exit();
  	tegra_clear_cpu_in_lp2();
  
  	local_fiq_enable();
  
  	smp_rmb();
  
  	return (entered_lp2) ? index : 0;
  }
  #endif
  
  int __init tegra30_cpuidle_init(void)
  {
  	return cpuidle_register(&tegra_idle_driver, NULL);
  }
  