LXR linux/drivers/power/reset/st-poweroff.c

   1/*
   2 * Copyright (C) 2014 STMicroelectronics
   3 *
   4 * Power off Restart driver, used in STMicroelectronics devices.
   5 *
   6 * Author: Christophe Kerello <christophe.kerello@st.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2, as
  10 * published by the Free Software Foundation.
  11 */
  12
  13#include <linux/module.h>
  14#include <linux/of.h>
  15#include <linux/of_platform.h>
  16#include <linux/platform_device.h>
  17#include <linux/mfd/syscon.h>
  18#include <linux/reboot.h>
  19#include <linux/regmap.h>
  20
  21struct reset_syscfg {
  22        struct regmap *regmap;
  23        /* syscfg used for reset */
  24        unsigned int offset_rst;
  25        unsigned int mask_rst;
  26        /* syscfg used for unmask the reset */
  27        unsigned int offset_rst_msk;
  28        unsigned int mask_rst_msk;
  29};
  30
  31/* STiH415 */
  32#define STIH415_SYSCFG_11       0x2c
  33#define STIH415_SYSCFG_15       0x3c
  34
  35static struct reset_syscfg stih415_reset = {
  36        .offset_rst = STIH415_SYSCFG_11,
  37        .mask_rst = BIT(0),
  38        .offset_rst_msk = STIH415_SYSCFG_15,
  39        .mask_rst_msk = BIT(0)
  40};
  41
  42/* STiH416 */
  43#define STIH416_SYSCFG_500      0x7d0
  44#define STIH416_SYSCFG_504      0x7e0
  45
  46static struct reset_syscfg stih416_reset = {
  47        .offset_rst = STIH416_SYSCFG_500,
  48        .mask_rst = BIT(0),
  49        .offset_rst_msk = STIH416_SYSCFG_504,
  50        .mask_rst_msk = BIT(0)
  51};
  52
  53/* STiH407 */
  54#define STIH407_SYSCFG_4000     0x0
  55#define STIH407_SYSCFG_4008     0x20
  56
  57static struct reset_syscfg stih407_reset = {
  58        .offset_rst = STIH407_SYSCFG_4000,
  59        .mask_rst = BIT(0),
  60        .offset_rst_msk = STIH407_SYSCFG_4008,
  61        .mask_rst_msk = BIT(0)
  62};
  63
  64/* STiD127 */
  65#define STID127_SYSCFG_700      0x0
  66#define STID127_SYSCFG_773      0x124
  67
  68static struct reset_syscfg stid127_reset = {
  69        .offset_rst = STID127_SYSCFG_773,
  70        .mask_rst = BIT(0),
  71        .offset_rst_msk = STID127_SYSCFG_700,
  72        .mask_rst_msk = BIT(8)
  73};
  74
  75static struct reset_syscfg *st_restart_syscfg;
  76
  77static int st_restart(struct notifier_block *this, unsigned long mode,
  78                      void *cmd)
  79{
  80        /* reset syscfg updated */
  81        regmap_update_bits(st_restart_syscfg->regmap,
  82                           st_restart_syscfg->offset_rst,
  83                           st_restart_syscfg->mask_rst,
  84                           0);
  85
  86        /* unmask the reset */
  87        regmap_update_bits(st_restart_syscfg->regmap,
  88                           st_restart_syscfg->offset_rst_msk,
  89                           st_restart_syscfg->mask_rst_msk,
  90                           0);
  91
  92        return NOTIFY_DONE;
  93}
  94
  95static struct notifier_block st_restart_nb = {
  96        .notifier_call = st_restart,
  97        .priority = 192,
  98};
  99
 100static const struct of_device_id st_reset_of_match[] = {
 101        {
 102                .compatible = "st,stih415-restart",
 103                .data = (void *)&stih415_reset,
 104        }, {
 105                .compatible = "st,stih416-restart",
 106                .data = (void *)&stih416_reset,
 107        }, {
 108                .compatible = "st,stih407-restart",
 109                .data = (void *)&stih407_reset,
 110        }, {
 111                .compatible = "st,stid127-restart",
 112                .data = (void *)&stid127_reset,
 113        },
 114        {}
 115};
 116
 117static int st_reset_probe(struct platform_device *pdev)
 118{
 119        struct device_node *np = pdev->dev.of_node;
 120        const struct of_device_id *match;
 121        struct device *dev = &pdev->dev;
 122
 123        match = of_match_device(st_reset_of_match, dev);
 124        if (!match)
 125                return -ENODEV;
 126
 127        st_restart_syscfg = (struct reset_syscfg *)match->data;
 128
 129        st_restart_syscfg->regmap =
 130                syscon_regmap_lookup_by_phandle(np, "st,syscfg");
 131        if (IS_ERR(st_restart_syscfg->regmap)) {
 132                dev_err(dev, "No syscfg phandle specified\n");
 133                return PTR_ERR(st_restart_syscfg->regmap);
 134        }
 135
 136        return register_restart_handler(&st_restart_nb);
 137}
 138
 139static struct platform_driver st_reset_driver = {
 140        .probe = st_reset_probe,
 141        .driver = {
 142                .name = "st_reset",
 143                .of_match_table = st_reset_of_match,
 144        },
 145};
 146
 147static int __init st_reset_init(void)
 148{
 149        return platform_driver_register(&st_reset_driver);
 150}
 151
 152device_initcall(st_reset_init);
 153
 154MODULE_AUTHOR("Christophe Kerello <christophe.kerello@st.com>");
 155MODULE_DESCRIPTION("STMicroelectronics Power off Restart driver");
 156MODULE_LICENSE("GPL v2");
 157