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
  21 struct 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
  35 static 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
  46 static 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
  57 static 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
  68 static 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
  75 static struct reset_syscfg *st_restart_syscfg;
  76
  77 static 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
  95 static struct notifier_block st_restart_nb = {
  96         .notifier_call = st_restart,
  97         .priority = 192,
  98 };
  99
 100 static 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
 117 static 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
 139 static 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
 147 static int __init st_reset_init(void)
 148 {
 149         return platform_driver_register(&st_reset_driver);
 150 }
 151
 152 device_initcall(st_reset_init);
 153
 154 MODULE_AUTHOR("Christophe Kerello <christophe.kerello@st.com>");
 155 MODULE_DESCRIPTION("STMicroelectronics Power off Restart driver");
 156 MODULE_LICENSE("GPL v2");