[deliverable/linux.git] / drivers / reset / reset-ath79.c

/*
 * Copyright (C) 2015 Alban Bedel <albeu@free.fr>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
#include <linux/reboot.h>

struct ath79_reset {
	struct reset_controller_dev rcdev;
	struct notifier_block restart_nb;
	void __iomem *base;
	spinlock_t lock;
};

#define FULL_CHIP_RESET 24

static int ath79_reset_update(struct reset_controller_dev *rcdev,
			unsigned long id, bool assert)
{
	struct ath79_reset *ath79_reset =
		container_of(rcdev, struct ath79_reset, rcdev);
	unsigned long flags;
	u32 val;

	spin_lock_irqsave(&ath79_reset->lock, flags);
	val = readl(ath79_reset->base);
	if (assert)
		val |= BIT(id);
	else
		val &= ~BIT(id);
	writel(val, ath79_reset->base);
	spin_unlock_irqrestore(&ath79_reset->lock, flags);

	return 0;
}

static int ath79_reset_assert(struct reset_controller_dev *rcdev,
			unsigned long id)
{
	return ath79_reset_update(rcdev, id, true);
}

static int ath79_reset_deassert(struct reset_controller_dev *rcdev,
				unsigned long id)
{
	return ath79_reset_update(rcdev, id, false);
}

static int ath79_reset_status(struct reset_controller_dev *rcdev,
			unsigned long id)
{
	struct ath79_reset *ath79_reset =
		container_of(rcdev, struct ath79_reset, rcdev);
	u32 val;

	val = readl(ath79_reset->base);

	return !!(val & BIT(id));
}

static const struct reset_control_ops ath79_reset_ops = {
	.assert = ath79_reset_assert,
	.deassert = ath79_reset_deassert,
	.status = ath79_reset_status,
};

static int ath79_reset_restart_handler(struct notifier_block *nb,
				unsigned long action, void *data)
{
	struct ath79_reset *ath79_reset =
		container_of(nb, struct ath79_reset, restart_nb);

	ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);

	return NOTIFY_DONE;
}

static int ath79_reset_probe(struct platform_device *pdev)
{
	struct ath79_reset *ath79_reset;
	struct resource *res;
	int err;

	ath79_reset = devm_kzalloc(&pdev->dev,
				sizeof(*ath79_reset), GFP_KERNEL);
	if (!ath79_reset)
		return -ENOMEM;

	platform_set_drvdata(pdev, ath79_reset);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ath79_reset->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(ath79_reset->base))
		return PTR_ERR(ath79_reset->base);

	spin_lock_init(&ath79_reset->lock);
	ath79_reset->rcdev.ops = &ath79_reset_ops;
	ath79_reset->rcdev.owner = THIS_MODULE;
	ath79_reset->rcdev.of_node = pdev->dev.of_node;
	ath79_reset->rcdev.of_reset_n_cells = 1;
	ath79_reset->rcdev.nr_resets = 32;

	err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev);
	if (err)
		return err;

	ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler;
	ath79_reset->restart_nb.priority = 128;

	err = register_restart_handler(&ath79_reset->restart_nb);
	if (err)
		dev_warn(&pdev->dev, "Failed to register restart handler\n");

	return 0;
}

static int ath79_reset_remove(struct platform_device *pdev)
{
	struct ath79_reset *ath79_reset = platform_get_drvdata(pdev);

	unregister_restart_handler(&ath79_reset->restart_nb);

	return 0;
}

static const struct of_device_id ath79_reset_dt_ids[] = {
	{ .compatible = "qca,ar7100-reset", },
	{ },
};
MODULE_DEVICE_TABLE(of, ath79_reset_dt_ids);

static struct platform_driver ath79_reset_driver = {
	.probe	= ath79_reset_probe,
	.remove = ath79_reset_remove,
	.driver = {
		.name		= "ath79-reset",
		.of_match_table	= ath79_reset_dt_ids,
	},
};
module_platform_driver(ath79_reset_driver);

MODULE_AUTHOR("Alban Bedel <albeu@free.fr>");
MODULE_DESCRIPTION("AR71xx Reset Controller Driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
ff591a91 AB	1	/*
	2	* Copyright (C) 2015 Alban Bedel <albeu@free.fr>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*/
	14
9e9ba091	15	#include <linux/io.h>
ff591a91 AB	16	#include <linux/module.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/reset-controller.h>
ba64e27e	19	#include <linux/reboot.h>
ff591a91 AB	20
	21	struct ath79_reset {
	22	struct reset_controller_dev rcdev;
ba64e27e	23	struct notifier_block restart_nb;
ff591a91 AB	24	void __iomem *base;
	25	spinlock_t lock;
	26	};
	27
ba64e27e AB	28	#define FULL_CHIP_RESET 24
ba64e27e AB	29
ff591a91 AB	30	static int ath79_reset_update(struct reset_controller_dev *rcdev,
	31	unsigned long id, bool assert)
	32	{
	33	struct ath79_reset *ath79_reset =
	34	container_of(rcdev, struct ath79_reset, rcdev);
	35	unsigned long flags;
	36	u32 val;
	37
	38	spin_lock_irqsave(&ath79_reset->lock, flags);
	39	val = readl(ath79_reset->base);
	40	if (assert)
	41	val \|= BIT(id);
	42	else
	43	val &= ~BIT(id);
	44	writel(val, ath79_reset->base);
	45	spin_unlock_irqrestore(&ath79_reset->lock, flags);
	46
	47	return 0;
	48	}
	49
	50	static int ath79_reset_assert(struct reset_controller_dev *rcdev,
	51	unsigned long id)
	52	{
	53	return ath79_reset_update(rcdev, id, true);
	54	}
	55
	56	static int ath79_reset_deassert(struct reset_controller_dev *rcdev,
	57	unsigned long id)
	58	{
	59	return ath79_reset_update(rcdev, id, false);
	60	}
	61
	62	static int ath79_reset_status(struct reset_controller_dev *rcdev,
	63	unsigned long id)
	64	{
	65	struct ath79_reset *ath79_reset =
	66	container_of(rcdev, struct ath79_reset, rcdev);
	67	u32 val;
	68
	69	val = readl(ath79_reset->base);
	70
	71	return !!(val & BIT(id));
	72	}
	73
d2f79f22	74	static const struct reset_control_ops ath79_reset_ops = {
ff591a91 AB	75	.assert = ath79_reset_assert,
	76	.deassert = ath79_reset_deassert,
	77	.status = ath79_reset_status,
	78	};
	79
ba64e27e AB	80	static int ath79_reset_restart_handler(struct notifier_block *nb,
	81	unsigned long action, void *data)
	82	{
	83	struct ath79_reset *ath79_reset =
	84	container_of(nb, struct ath79_reset, restart_nb);
	85
	86	ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);
	87
	88	return NOTIFY_DONE;
	89	}
	90
ff591a91 AB	91	static int ath79_reset_probe(struct platform_device *pdev)
	92	{
	93	struct ath79_reset *ath79_reset;
	94	struct resource *res;
ba64e27e	95	int err;
ff591a91 AB	96
	97	ath79_reset = devm_kzalloc(&pdev->dev,
	98	sizeof(*ath79_reset), GFP_KERNEL);
	99	if (!ath79_reset)
	100	return -ENOMEM;
	101
	102	platform_set_drvdata(pdev, ath79_reset);
	103
	104	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	105	ath79_reset->base = devm_ioremap_resource(&pdev->dev, res);
	106	if (IS_ERR(ath79_reset->base))
	107	return PTR_ERR(ath79_reset->base);
	108
f319cb84	109	spin_lock_init(&ath79_reset->lock);
ff591a91 AB	110	ath79_reset->rcdev.ops = &ath79_reset_ops;
	111	ath79_reset->rcdev.owner = THIS_MODULE;
	112	ath79_reset->rcdev.of_node = pdev->dev.of_node;
	113	ath79_reset->rcdev.of_reset_n_cells = 1;
	114	ath79_reset->rcdev.nr_resets = 32;
	115
56865f45	116	err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev);
ba64e27e AB	117	if (err)
	118	return err;
	119
	120	ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler;
	121	ath79_reset->restart_nb.priority = 128;
	122
	123	err = register_restart_handler(&ath79_reset->restart_nb);
	124	if (err)
	125	dev_warn(&pdev->dev, "Failed to register restart handler\n");
	126
	127	return 0;
ff591a91 AB	128	}
	129
	130	static int ath79_reset_remove(struct platform_device *pdev)
	131	{
	132	struct ath79_reset *ath79_reset = platform_get_drvdata(pdev);
	133
ba64e27e	134	unregister_restart_handler(&ath79_reset->restart_nb);
ff591a91 AB	135
	136	return 0;
	137	}
	138
	139	static const struct of_device_id ath79_reset_dt_ids[] = {
	140	{ .compatible = "qca,ar7100-reset", },
	141	{ },
	142	};
	143	MODULE_DEVICE_TABLE(of, ath79_reset_dt_ids);
	144
	145	static struct platform_driver ath79_reset_driver = {
	146	.probe = ath79_reset_probe,
	147	.remove = ath79_reset_remove,
	148	.driver = {
	149	.name = "ath79-reset",
	150	.of_match_table = ath79_reset_dt_ids,
	151	},
	152	};
	153	module_platform_driver(ath79_reset_driver);
	154
	155	MODULE_AUTHOR("Alban Bedel <albeu@free.fr>");
	156	MODULE_DESCRIPTION("AR71xx Reset Controller Driver");
	157	MODULE_LICENSE("GPL");