/*
   * Copyright (c) 2011-2014 Samsung Electronics Co., Ltd.

   *		http://www.samsung.com
   *

   * Coupled cpuidle support based on the work of:
   *	Colin Cross <ccross@android.com>
   *	Daniel Lezcano <daniel.lezcano@linaro.org>
   *

   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
  */

  #include <linux/cpuidle.h>

  #include <linux/cpu_pm.h>

  #include <linux/export.h>

  #include <linux/init.h>

  #include <linux/platform_device.h>

  #include <linux/of.h>
  #include <linux/platform_data/cpuidle-exynos.h>

  #include <asm/suspend.h>

  #include <asm/cpuidle.h>

  static atomic_t exynos_idle_barrier;
  
  static struct cpuidle_exynos_data *exynos_cpuidle_pdata;

  static void (*exynos_enter_aftr)(void);

  static int exynos_enter_coupled_lowpower(struct cpuidle_device *dev,
  					 struct cpuidle_driver *drv,
  					 int index)
  {
  	int ret;
  
  	exynos_cpuidle_pdata->pre_enter_aftr();
  
  	/*
  	 * Waiting all cpus to reach this point at the same moment
  	 */
  	cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);
  
  	/*
  	 * Both cpus will reach this point at the same time
  	 */
  	ret = dev->cpu ? exynos_cpuidle_pdata->cpu1_powerdown()
  		       : exynos_cpuidle_pdata->cpu0_enter_aftr();
  	if (ret)
  		index = ret;
  
  	/*
  	 * Waiting all cpus to finish the power sequence before going further
  	 */
  	cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);
  
  	exynos_cpuidle_pdata->post_enter_aftr();
  
  	return index;
  }

  static int exynos_enter_lowpower(struct cpuidle_device *dev,

  				struct cpuidle_driver *drv,
  				int index)
  {
  	int new_index = index;

  	/* AFTR can only be entered when cores other than CPU0 are offline */
  	if (num_online_cpus() > 1 || dev->cpu != 0)

  		new_index = drv->safe_state_index;
  
  	if (new_index == 0)

  		return arm_cpuidle_simple_enter(dev, drv, new_index);

  
  	exynos_enter_aftr();
  
  	return new_index;

  }

  static struct cpuidle_driver exynos_idle_driver = {
  	.name			= "exynos_idle",

  	.owner			= THIS_MODULE,
  	.states = {
  		[0] = ARM_CPUIDLE_WFI_STATE,
  		[1] = {

  			.enter			= exynos_enter_lowpower,

  			.exit_latency		= 300,

  			.target_residency	= 10000,

  			.name			= "C1",
  			.desc			= "ARM power down",
  		},
  	},
  	.state_count = 2,
  	.safe_state_index = 0,
  };

  static struct cpuidle_driver exynos_coupled_idle_driver = {
  	.name			= "exynos_coupled_idle",
  	.owner			= THIS_MODULE,
  	.states = {
  		[0] = ARM_CPUIDLE_WFI_STATE,
  		[1] = {
  			.enter			= exynos_enter_coupled_lowpower,
  			.exit_latency		= 5000,
  			.target_residency	= 10000,
  			.flags			= CPUIDLE_FLAG_COUPLED |
  						  CPUIDLE_FLAG_TIMER_STOP,
  			.name			= "C1",
  			.desc			= "ARM power down",
  		},
  	},
  	.state_count = 2,
  	.safe_state_index = 0,
  };

  static int exynos_cpuidle_probe(struct platform_device *pdev)

  {

  	int ret;

  	if (IS_ENABLED(CONFIG_SMP) &&

  	    (of_machine_is_compatible("samsung,exynos4210") ||
  	     of_machine_is_compatible("samsung,exynos3250"))) {

  		exynos_cpuidle_pdata = pdev->dev.platform_data;
  
  		ret = cpuidle_register(&exynos_coupled_idle_driver,
  				       cpu_possible_mask);
  	} else {
  		exynos_enter_aftr = (void *)(pdev->dev.platform_data);
  
  		ret = cpuidle_register(&exynos_idle_driver, NULL);
  	}

  	if (ret) {

  		dev_err(&pdev->dev, "failed to register cpuidle driver
  ");

  		return ret;

  	}

  	return 0;
  }

  
  static struct platform_driver exynos_cpuidle_driver = {
  	.probe	= exynos_cpuidle_probe,
  	.driver = {
  		.name = "exynos_cpuidle",

  	},
  };

  builtin_platform_driver(exynos_cpuidle_driver);