drivers/cpuidle/cpuidle-clps711x.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  CLPS711X CPU idle driver
   4  *
   5  *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
   6  */
   7
   8 #include <linux/cpuidle.h>
   9 #include <linux/err.h>
  10 #include <linux/io.h>
  11 #include <linux/init.h>
  12 #include <linux/platform_device.h>
  13
  14 #define CLPS711X_CPUIDLE_NAME   "clps711x-cpuidle"
  15
  16 static void __iomem *clps711x_halt;
  17
  18 static int clps711x_cpuidle_halt(struct cpuidle_device *dev,
  19                                  struct cpuidle_driver *drv, int index)
  20 {
  21         writel(0xaa, clps711x_halt);
  22
  23         return index;
  24 }
  25
  26 static struct cpuidle_driver clps711x_idle_driver = {
  27         .name           = CLPS711X_CPUIDLE_NAME,
  28         .owner          = THIS_MODULE,
  29         .states[0]      = {
  30                 .name           = "HALT",
  31                 .desc           = "CLPS711X HALT",
  32                 .enter          = clps711x_cpuidle_halt,
  33                 .exit_latency   = 1,
  34         },
  35         .state_count    = 1,
  36 };
  37
  38 static int __init clps711x_cpuidle_probe(struct platform_device *pdev)
  39 {
  40         clps711x_halt = devm_platform_ioremap_resource(pdev, 0);
  41         if (IS_ERR(clps711x_halt))
  42                 return PTR_ERR(clps711x_halt);
  43
  44         return cpuidle_register(&clps711x_idle_driver, NULL);
  45 }
  46
  47 static struct platform_driver clps711x_cpuidle_driver = {
  48         .driver = {
  49                 .name   = CLPS711X_CPUIDLE_NAME,
  50         },
  51 };
  52 builtin_platform_driver_probe(clps711x_cpuidle_driver, clps711x_cpuidle_probe);