arch/arm/mach-s3c/cpuidle-s3c64xx.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright (c) 2011 Wolfson Microelectronics, plc
   4 // Copyright (c) 2011 Samsung Electronics Co., Ltd.
   5 //              http://www.samsung.com
   6
   7 #include <linux/kernel.h>
   8 #include <linux/init.h>
   9 #include <linux/cpuidle.h>
  10 #include <linux/io.h>
  11 #include <linux/export.h>
  12 #include <linux/time.h>
  13
  14 #include <asm/cpuidle.h>
  15
  16 #include "cpu.h"
  17 #include "map.h"
  18
  19 #include "regs-sys-s3c64xx.h"
  20 #include "regs-syscon-power-s3c64xx.h"
  21
  22 static __cpuidle int s3c64xx_enter_idle(struct cpuidle_device *dev,
  23                                         struct cpuidle_driver *drv, int index)
  24 {
  25         unsigned long tmp;
  26
  27         /* Setup PWRCFG to enter idle mode */
  28         tmp = __raw_readl(S3C64XX_PWR_CFG);
  29         tmp &= ~S3C64XX_PWRCFG_CFG_WFI_MASK;
  30         tmp |= S3C64XX_PWRCFG_CFG_WFI_IDLE;
  31         __raw_writel(tmp, S3C64XX_PWR_CFG);
  32
  33         cpu_do_idle();
  34
  35         return index;
  36 }
  37
  38 static struct cpuidle_driver s3c64xx_cpuidle_driver = {
  39         .name   = "s3c64xx_cpuidle",
  40         .owner  = THIS_MODULE,
  41         .states = {
  42                 {
  43                         .enter            = s3c64xx_enter_idle,
  44                         .exit_latency     = 1,
  45                         .target_residency = 1,
  46                         .name             = "IDLE",
  47                         .desc             = "System active, ARM gated",
  48                 },
  49         },
  50         .state_count = 1,
  51 };
  52
  53 static int __init s3c64xx_init_cpuidle(void)
  54 {
  55         if (soc_is_s3c64xx())
  56                 return cpuidle_register(&s3c64xx_cpuidle_driver, NULL);
  57         return 0;
  58 }
  59 device_initcall(s3c64xx_init_cpuidle);