| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 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 | /* STiH407 */ |
| 32 | #define STIH407_SYSCFG_4000 0x0 |
| 33 | #define STIH407_SYSCFG_4008 0x20 |
| 34 | |
| 35 | static struct reset_syscfg stih407_reset = { |
| 36 | .offset_rst = STIH407_SYSCFG_4000, |
| 37 | .mask_rst = BIT(0), |
| 38 | .offset_rst_msk = STIH407_SYSCFG_4008, |
| 39 | .mask_rst_msk = BIT(0) |
| 40 | }; |
| 41 | |
| 42 | |
| 43 | static struct reset_syscfg *st_restart_syscfg; |
| 44 | |
| 45 | static int st_restart(struct notifier_block *this, unsigned long mode, |
| 46 | void *cmd) |
| 47 | { |
| 48 | /* reset syscfg updated */ |
| 49 | regmap_update_bits(st_restart_syscfg->regmap, |
| 50 | st_restart_syscfg->offset_rst, |
| 51 | st_restart_syscfg->mask_rst, |
| 52 | 0); |
| 53 | |
| 54 | /* unmask the reset */ |
| 55 | regmap_update_bits(st_restart_syscfg->regmap, |
| 56 | st_restart_syscfg->offset_rst_msk, |
| 57 | st_restart_syscfg->mask_rst_msk, |
| 58 | 0); |
| 59 | |
| 60 | return NOTIFY_DONE; |
| 61 | } |
| 62 | |
| 63 | static struct notifier_block st_restart_nb = { |
| 64 | .notifier_call = st_restart, |
| 65 | .priority = 192, |
| 66 | }; |
| 67 | |
| 68 | static const struct of_device_id st_reset_of_match[] = { |
| 69 | { |
| 70 | .compatible = "st,stih407-restart", |
| 71 | .data = (void *)&stih407_reset, |
| 72 | }, |
| 73 | {} |
| 74 | }; |
| 75 | |
| 76 | static int st_reset_probe(struct platform_device *pdev) |
| 77 | { |
| 78 | struct device_node *np = pdev->dev.of_node; |
| 79 | const struct of_device_id *match; |
| 80 | struct device *dev = &pdev->dev; |
| 81 | |
| 82 | match = of_match_device(st_reset_of_match, dev); |
| 83 | if (!match) |
| 84 | return -ENODEV; |
| 85 | |
| 86 | st_restart_syscfg = (struct reset_syscfg *)match->data; |
| 87 | |
| 88 | st_restart_syscfg->regmap = |
| 89 | syscon_regmap_lookup_by_phandle(np, "st,syscfg"); |
| 90 | if (IS_ERR(st_restart_syscfg->regmap)) { |
| 91 | dev_err(dev, "No syscfg phandle specified\n"); |
| 92 | return PTR_ERR(st_restart_syscfg->regmap); |
| 93 | } |
| 94 | |
| 95 | return register_restart_handler(&st_restart_nb); |
| 96 | } |
| 97 | |
| 98 | static struct platform_driver st_reset_driver = { |
| 99 | .probe = st_reset_probe, |
| 100 | .driver = { |
| 101 | .name = "st_reset", |
| 102 | .of_match_table = st_reset_of_match, |
| 103 | }, |
| 104 | }; |
| 105 | |
| 106 | static int __init st_reset_init(void) |
| 107 | { |
| 108 | return platform_driver_register(&st_reset_driver); |
| 109 | } |
| 110 | |
| 111 | device_initcall(st_reset_init); |
| 112 | |
| 113 | MODULE_AUTHOR("Christophe Kerello <christophe.kerello@st.com>"); |
| 114 | MODULE_DESCRIPTION("STMicroelectronics Power off Restart driver"); |
| 115 | MODULE_LICENSE("GPL v2"); |