arm/mach-s3c/cpuidle-s3c64xx.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 //
0003 // Copyright (c) 2011 Wolfson Microelectronics, plc
0004 // Copyright (c) 2011 Samsung Electronics Co., Ltd.
0005 //      http://www.samsung.com
0006
0007 #include <linux/kernel.h>
0008 #include <linux/init.h>
0009 #include <linux/cpuidle.h>
0010 #include <linux/io.h>
0011 #include <linux/export.h>
0012 #include <linux/time.h>
0013
0014 #include <asm/cpuidle.h>
0015
0016 #include "cpu.h"
0017 #include "map.h"
0018
0019 #include "regs-sys-s3c64xx.h"
0020 #include "regs-syscon-power-s3c64xx.h"
0021
0022 static int s3c64xx_enter_idle(struct cpuidle_device *dev,
0023                   struct cpuidle_driver *drv,
0024                   int index)
0025 {
0026     unsigned long tmp;
0027
0028     /* Setup PWRCFG to enter idle mode */
0029     tmp = __raw_readl(S3C64XX_PWR_CFG);
0030     tmp &= ~S3C64XX_PWRCFG_CFG_WFI_MASK;
0031     tmp |= S3C64XX_PWRCFG_CFG_WFI_IDLE;
0032     __raw_writel(tmp, S3C64XX_PWR_CFG);
0033
0034     cpu_do_idle();
0035
0036     return index;
0037 }
0038
0039 static struct cpuidle_driver s3c64xx_cpuidle_driver = {
0040     .name   = "s3c64xx_cpuidle",
0041     .owner  = THIS_MODULE,
0042     .states = {
0043         {
0044             .enter            = s3c64xx_enter_idle,
0045             .exit_latency     = 1,
0046             .target_residency = 1,
0047             .name             = "IDLE",
0048             .desc             = "System active, ARM gated",
0049         },
0050     },
0051     .state_count = 1,
0052 };
0053
0054 static int __init s3c64xx_init_cpuidle(void)
0055 {
0056     if (soc_is_s3c64xx())
0057         return cpuidle_register(&s3c64xx_cpuidle_driver, NULL);
0058     return 0;
0059 }
0060 device_initcall(s3c64xx_init_cpuidle);