of_device_id is always used as const. (See driver.of_match_table and open firmware functions) Signed-off-by: Fabian Frederick <fabf@skynet.be> [for vexpress] Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Sebastian Reichel <sre@kernel.org>
		
			
				
	
	
		
			156 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			156 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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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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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * Copyright (C) 2012 ARM Limited
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 */
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#include <linux/delay.h>
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#include <linux/notifier.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/reboot.h>
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#include <linux/stat.h>
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#include <linux/vexpress.h>
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static void vexpress_reset_do(struct device *dev, const char *what)
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{
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	int err = -ENOENT;
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	struct regmap *reg = dev_get_drvdata(dev);
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	if (reg) {
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		err = regmap_write(reg, 0, 0);
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		if (!err)
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			mdelay(1000);
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	}
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	dev_emerg(dev, "Unable to %s (%d)\n", what, err);
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}
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static struct device *vexpress_power_off_device;
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static void vexpress_power_off(void)
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{
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	vexpress_reset_do(vexpress_power_off_device, "power off");
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}
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static struct device *vexpress_restart_device;
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static int vexpress_restart(struct notifier_block *this, unsigned long mode,
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			     void *cmd)
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{
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	vexpress_reset_do(vexpress_restart_device, "restart");
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	return NOTIFY_DONE;
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}
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static struct notifier_block vexpress_restart_nb = {
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	.notifier_call = vexpress_restart,
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	.priority = 128,
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};
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static ssize_t vexpress_reset_active_show(struct device *dev,
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		struct device_attribute *attr, char *buf)
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{
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	return sprintf(buf, "%d\n", vexpress_restart_device == dev);
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}
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static ssize_t vexpress_reset_active_store(struct device *dev,
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		struct device_attribute *attr, const char *buf, size_t count)
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{
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	long value;
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	int err = kstrtol(buf, 0, &value);
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	if (!err && value)
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		vexpress_restart_device = dev;
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	return err ? err : count;
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}
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DEVICE_ATTR(active, S_IRUGO | S_IWUSR, vexpress_reset_active_show,
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		vexpress_reset_active_store);
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enum vexpress_reset_func { FUNC_RESET, FUNC_SHUTDOWN, FUNC_REBOOT };
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static const struct of_device_id vexpress_reset_of_match[] = {
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	{
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		.compatible = "arm,vexpress-reset",
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		.data = (void *)FUNC_RESET,
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	}, {
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		.compatible = "arm,vexpress-shutdown",
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		.data = (void *)FUNC_SHUTDOWN
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	}, {
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		.compatible = "arm,vexpress-reboot",
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		.data = (void *)FUNC_REBOOT
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	},
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	{}
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};
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static int _vexpress_register_restart_handler(struct device *dev)
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{
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	int err;
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	vexpress_restart_device = dev;
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	err = register_restart_handler(&vexpress_restart_nb);
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	if (err) {
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		dev_err(dev, "cannot register restart handler (err=%d)\n", err);
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		return err;
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	}
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	device_create_file(dev, &dev_attr_active);
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	return 0;
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}
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static int vexpress_reset_probe(struct platform_device *pdev)
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{
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	const struct of_device_id *match =
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			of_match_device(vexpress_reset_of_match, &pdev->dev);
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	struct regmap *regmap;
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	int ret = 0;
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	if (!match)
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		return -EINVAL;
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	regmap = devm_regmap_init_vexpress_config(&pdev->dev);
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	if (IS_ERR(regmap))
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		return PTR_ERR(regmap);
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	dev_set_drvdata(&pdev->dev, regmap);
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	switch ((enum vexpress_reset_func)match->data) {
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	case FUNC_SHUTDOWN:
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		vexpress_power_off_device = &pdev->dev;
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		pm_power_off = vexpress_power_off;
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		break;
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	case FUNC_RESET:
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		if (!vexpress_restart_device)
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			ret = _vexpress_register_restart_handler(&pdev->dev);
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		break;
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	case FUNC_REBOOT:
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		ret = _vexpress_register_restart_handler(&pdev->dev);
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		break;
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	};
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	return ret;
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}
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static struct platform_driver vexpress_reset_driver = {
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	.probe = vexpress_reset_probe,
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	.driver = {
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		.name = "vexpress-reset",
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		.of_match_table = vexpress_reset_of_match,
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	},
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};
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static int __init vexpress_reset_init(void)
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{
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	return platform_driver_register(&vexpress_reset_driver);
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}
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device_initcall(vexpress_reset_init);
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