113 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			113 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| /*
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| 
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| static struct reset_syscfg *st_restart_syscfg;
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| 
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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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| 
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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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| 
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| 	return NOTIFY_DONE;
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| }
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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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| 
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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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| 
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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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| 
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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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| 
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| 	st_restart_syscfg = (struct reset_syscfg *)match->data;
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| 
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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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| 
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| 	return register_restart_handler(&st_restart_nb);
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| }
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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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| 
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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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| 
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| device_initcall(st_reset_init);
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| 
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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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