/*

   * CPU idle Marvell Kirkwood SoCs
   *
   * This file is licensed under the terms of the GNU General Public
   * License version 2.  This program is licensed "as is" without any
   * warranty of any kind, whether express or implied.
   *
   * The cpu idle uses wait-for-interrupt and DDR self refresh in order
   * to implement two idle states -
   * #1 wait-for-interrupt
   * #2 wait-for-interrupt and DDR self refresh

   *
   * Maintainer: Jason Cooper <jason@lakedaemon.net>
   * Maintainer: Andrew Lunn <andrew@lunn.ch>

   */
  
  #include <linux/kernel.h>

  #include <linux/module.h>

  #include <linux/init.h>
  #include <linux/platform_device.h>
  #include <linux/cpuidle.h>
  #include <linux/io.h>

  #include <linux/export.h>

  #include <asm/proc-fns.h>

  #include <asm/cpuidle.h>

  
  #define KIRKWOOD_MAX_STATES	2

  static void __iomem *ddr_operation_base;

  /* Actual code that puts the SoC in different idle states */
  static int kirkwood_enter_idle(struct cpuidle_device *dev,

  			       struct cpuidle_driver *drv,

  			       int index)

  {

  	writel(0x7, ddr_operation_base);

  	cpu_do_idle();

  
  	return index;

  }

  static struct cpuidle_driver kirkwood_idle_driver = {
  	.name			= "kirkwood_idle",
  	.owner			= THIS_MODULE,

  	.states[0]		= ARM_CPUIDLE_WFI_STATE,
  	.states[1]		= {
  		.enter			= kirkwood_enter_idle,
  		.exit_latency		= 10,
  		.target_residency	= 100000,

  		.name			= "DDR SR",
  		.desc			= "WFI and DDR Self Refresh",
  	},
  	.state_count = KIRKWOOD_MAX_STATES,
  };

  /* Initialize CPU idle by registering the idle states */

  static int kirkwood_cpuidle_probe(struct platform_device *pdev)

  {

  	struct resource *res;
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

  	ddr_operation_base = devm_ioremap_resource(&pdev->dev, res);
  	if (IS_ERR(ddr_operation_base))
  		return PTR_ERR(ddr_operation_base);

  	return cpuidle_register(&kirkwood_idle_driver, NULL);

  }

  static int kirkwood_cpuidle_remove(struct platform_device *pdev)

  {

  	cpuidle_unregister(&kirkwood_idle_driver);

  	return 0;
  }
  
  static struct platform_driver kirkwood_cpuidle_driver = {
  	.probe = kirkwood_cpuidle_probe,
  	.remove = kirkwood_cpuidle_remove,
  	.driver = {
  		   .name = "kirkwood_cpuidle",

  		   },
  };
  
  module_platform_driver(kirkwood_cpuidle_driver);
  
  MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
  MODULE_DESCRIPTION("Kirkwood cpu idle driver");
  MODULE_LICENSE("GPL v2");
  MODULE_ALIAS("platform:kirkwood-cpuidle");