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