1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2f0745f36SLee Jones /* 3f0745f36SLee Jones * Copyright (C) 2014 STMicroelectronics 4f0745f36SLee Jones * 5f0745f36SLee Jones * Power off Restart driver, used in STMicroelectronics devices. 6f0745f36SLee Jones * 7f0745f36SLee Jones * Author: Christophe Kerello <christophe.kerello@st.com> 8f0745f36SLee Jones */ 9f0745f36SLee Jones 10f0745f36SLee Jones #include <linux/module.h> 11f0745f36SLee Jones #include <linux/of.h> 12f0745f36SLee Jones #include <linux/of_platform.h> 13f0745f36SLee Jones #include <linux/platform_device.h> 14f0745f36SLee Jones #include <linux/mfd/syscon.h> 15453fe4f1SGuenter Roeck #include <linux/reboot.h> 16f0745f36SLee Jones #include <linux/regmap.h> 17f0745f36SLee Jones 18f0745f36SLee Jones struct reset_syscfg { 19f0745f36SLee Jones struct regmap *regmap; 20f0745f36SLee Jones /* syscfg used for reset */ 21f0745f36SLee Jones unsigned int offset_rst; 22f0745f36SLee Jones unsigned int mask_rst; 23f0745f36SLee Jones /* syscfg used for unmask the reset */ 24f0745f36SLee Jones unsigned int offset_rst_msk; 25f0745f36SLee Jones unsigned int mask_rst_msk; 26f0745f36SLee Jones }; 27f0745f36SLee Jones 28f0745f36SLee Jones /* STiH407 */ 29f0745f36SLee Jones #define STIH407_SYSCFG_4000 0x0 30f0745f36SLee Jones #define STIH407_SYSCFG_4008 0x20 31f0745f36SLee Jones 32f0745f36SLee Jones static struct reset_syscfg stih407_reset = { 33f0745f36SLee Jones .offset_rst = STIH407_SYSCFG_4000, 34f0745f36SLee Jones .mask_rst = BIT(0), 35f0745f36SLee Jones .offset_rst_msk = STIH407_SYSCFG_4008, 36f0745f36SLee Jones .mask_rst_msk = BIT(0) 37f0745f36SLee Jones }; 38f0745f36SLee Jones 39f0745f36SLee Jones 40f0745f36SLee Jones static struct reset_syscfg *st_restart_syscfg; 41f0745f36SLee Jones 42453fe4f1SGuenter Roeck static int st_restart(struct notifier_block *this, unsigned long mode, 43453fe4f1SGuenter Roeck void *cmd) 44f0745f36SLee Jones { 45f0745f36SLee Jones /* reset syscfg updated */ 46f0745f36SLee Jones regmap_update_bits(st_restart_syscfg->regmap, 47f0745f36SLee Jones st_restart_syscfg->offset_rst, 48f0745f36SLee Jones st_restart_syscfg->mask_rst, 49f0745f36SLee Jones 0); 50f0745f36SLee Jones 51f0745f36SLee Jones /* unmask the reset */ 52f0745f36SLee Jones regmap_update_bits(st_restart_syscfg->regmap, 53f0745f36SLee Jones st_restart_syscfg->offset_rst_msk, 54f0745f36SLee Jones st_restart_syscfg->mask_rst_msk, 55f0745f36SLee Jones 0); 56453fe4f1SGuenter Roeck 57453fe4f1SGuenter Roeck return NOTIFY_DONE; 58f0745f36SLee Jones } 59f0745f36SLee Jones 60453fe4f1SGuenter Roeck static struct notifier_block st_restart_nb = { 61453fe4f1SGuenter Roeck .notifier_call = st_restart, 62453fe4f1SGuenter Roeck .priority = 192, 63453fe4f1SGuenter Roeck }; 64453fe4f1SGuenter Roeck 658fb08855SFabian Frederick static const struct of_device_id st_reset_of_match[] = { 66f0745f36SLee Jones { 67f0745f36SLee Jones .compatible = "st,stih407-restart", 68f0745f36SLee Jones .data = (void *)&stih407_reset, 69f0745f36SLee Jones }, 70f0745f36SLee Jones {} 71f0745f36SLee Jones }; 72f0745f36SLee Jones 73f0745f36SLee Jones static int st_reset_probe(struct platform_device *pdev) 74f0745f36SLee Jones { 75f0745f36SLee Jones struct device_node *np = pdev->dev.of_node; 76f0745f36SLee Jones const struct of_device_id *match; 77f0745f36SLee Jones struct device *dev = &pdev->dev; 78f0745f36SLee Jones 79f0745f36SLee Jones match = of_match_device(st_reset_of_match, dev); 80f0745f36SLee Jones if (!match) 81f0745f36SLee Jones return -ENODEV; 82f0745f36SLee Jones 83f0745f36SLee Jones st_restart_syscfg = (struct reset_syscfg *)match->data; 84f0745f36SLee Jones 85f0745f36SLee Jones st_restart_syscfg->regmap = 86f0745f36SLee Jones syscon_regmap_lookup_by_phandle(np, "st,syscfg"); 87f0745f36SLee Jones if (IS_ERR(st_restart_syscfg->regmap)) { 88f0745f36SLee Jones dev_err(dev, "No syscfg phandle specified\n"); 89f0745f36SLee Jones return PTR_ERR(st_restart_syscfg->regmap); 90f0745f36SLee Jones } 91f0745f36SLee Jones 92453fe4f1SGuenter Roeck return register_restart_handler(&st_restart_nb); 93f0745f36SLee Jones } 94f0745f36SLee Jones 95f0745f36SLee Jones static struct platform_driver st_reset_driver = { 96f0745f36SLee Jones .probe = st_reset_probe, 97f0745f36SLee Jones .driver = { 98f0745f36SLee Jones .name = "st_reset", 99f0745f36SLee Jones .of_match_table = st_reset_of_match, 100f0745f36SLee Jones }, 101f0745f36SLee Jones }; 102f0745f36SLee Jones 103f0745f36SLee Jones static int __init st_reset_init(void) 104f0745f36SLee Jones { 105f0745f36SLee Jones return platform_driver_register(&st_reset_driver); 106f0745f36SLee Jones } 107f0745f36SLee Jones 108f0745f36SLee Jones device_initcall(st_reset_init); 109f0745f36SLee Jones 110f0745f36SLee Jones MODULE_AUTHOR("Christophe Kerello <christophe.kerello@st.com>"); 111f0745f36SLee Jones MODULE_DESCRIPTION("STMicroelectronics Power off Restart driver"); 112f0745f36SLee Jones MODULE_LICENSE("GPL v2"); 113