/* * Copyright (C) 2014 STMicroelectronics * * Power off Restart driver, used in STMicroelectronics devices. * * Author: Christophe Kerello <christophe.kerello@st.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, as * published by the Free Software Foundation. */ #include <linux/module.h> #include <linux/of.h> #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/mfd/syscon.h> #include <linux/reboot.h> #include <linux/regmap.h> struct reset_syscfg { struct regmap *regmap; /* syscfg used for reset */ unsigned int offset_rst; unsigned int mask_rst; /* syscfg used for unmask the reset */ unsigned int offset_rst_msk; unsigned int mask_rst_msk; }; /* STiH407 */ #define STIH407_SYSCFG_4000 0x0 #define STIH407_SYSCFG_4008 0x20 static struct reset_syscfg stih407_reset = { .offset_rst = STIH407_SYSCFG_4000, .mask_rst = BIT(0), .offset_rst_msk = STIH407_SYSCFG_4008, .mask_rst_msk = BIT(0) }; static struct reset_syscfg *st_restart_syscfg; static int st_restart(struct notifier_block *this, unsigned long mode, void *cmd) { /* reset syscfg updated */ regmap_update_bits(st_restart_syscfg->regmap, st_restart_syscfg->offset_rst, st_restart_syscfg->mask_rst, 0); /* unmask the reset */ regmap_update_bits(st_restart_syscfg->regmap, st_restart_syscfg->offset_rst_msk, st_restart_syscfg->mask_rst_msk, 0); return NOTIFY_DONE; } static struct notifier_block st_restart_nb = { .notifier_call = st_restart, .priority = 192, }; static const struct of_device_id st_reset_of_match[] = { { .compatible = "st,stih407-restart", .data = (void *)&stih407_reset, }, {} }; static int st_reset_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; const struct of_device_id *match; struct device *dev = &pdev->dev; match = of_match_device(st_reset_of_match, dev); if (!match) return -ENODEV; st_restart_syscfg = (struct reset_syscfg *)match->data; st_restart_syscfg->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); if (IS_ERR(st_restart_syscfg->regmap)) { dev_err(dev, "No syscfg phandle specified\n"); return PTR_ERR(st_restart_syscfg->regmap); } return register_restart_handler(&st_restart_nb); } static struct platform_driver st_reset_driver = { .probe = st_reset_probe, .driver = { .name = "st_reset", .of_match_table = st_reset_of_match, }, }; static int __init st_reset_init(void) { return platform_driver_register(&st_reset_driver); } device_initcall(st_reset_init); MODULE_AUTHOR("Christophe Kerello <christophe.kerello@st.com>"); MODULE_DESCRIPTION("STMicroelectronics Power off Restart driver"); MODULE_LICENSE("GPL v2");