drivers/cpuidle/cpuidle-clps711x.c

   1 /*
   2  *  CLPS711X CPU idle driver
   3  *
   4  *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/cpuidle.h>
  13 #include <linux/err.h>
  14 #include <linux/io.h>
  15 #include <linux/module.h>
  16 #include <linux/platform_device.h>
  17
  18 #define CLPS711X_CPUIDLE_NAME   "clps711x-cpuidle"
  19
  20 static void __iomem *clps711x_halt;
  21
  22 static int clps711x_cpuidle_halt(struct cpuidle_device *dev,
  23                                  struct cpuidle_driver *drv, int index)
  24 {
  25         writel(0xaa, clps711x_halt);
  26
  27         return index;
  28 }
  29
  30 static struct cpuidle_driver clps711x_idle_driver = {
  31         .name           = CLPS711X_CPUIDLE_NAME,
  32         .owner          = THIS_MODULE,
  33         .states[0]      = {
  34                 .name           = "HALT",
  35                 .desc           = "CLPS711X HALT",
  36                 .enter          = clps711x_cpuidle_halt,
  37                 .exit_latency   = 1,
  38         },
  39         .state_count    = 1,
  40 };
  41
  42 static int __init clps711x_cpuidle_probe(struct platform_device *pdev)
  43 {
  44         struct resource *res;
  45
  46         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  47         clps711x_halt = devm_ioremap_resource(&pdev->dev, res);
  48         if (IS_ERR(clps711x_halt))
  49                 return PTR_ERR(clps711x_halt);
  50
  51         return cpuidle_register(&clps711x_idle_driver, NULL);
  52 }
  53
  54 static struct platform_driver clps711x_cpuidle_driver = {
  55         .driver = {
  56                 .name   = CLPS711X_CPUIDLE_NAME,
  57         },
  58 };
  59 module_platform_driver_probe(clps711x_cpuidle_driver, clps711x_cpuidle_probe);
  60
  61 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
  62 MODULE_DESCRIPTION("CLPS711X CPU idle driver");
  63 MODULE_LICENSE("GPL");