[mirror_ubuntu-focal-kernel.git] / drivers / reset / reset-ath79.c

/*
 * AR71xx Reset Controller Driver
 * Author: Alban Bedel
 *
 * 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/init.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 const struct of_device_id ath79_reset_dt_ids[] = {
	{ .compatible = "qca,ar7100-reset", },
	{ },
};

static struct platform_driver ath79_reset_driver = {
	.probe	= ath79_reset_probe,
	.driver = {
		.name			= "ath79-reset",
		.of_match_table		= ath79_reset_dt_ids,
		.suppress_bind_attrs	= true,
	},
};
builtin_platform_driver(ath79_reset_driver);
Commit	Line	Data
ff591a91	1	/*
90ce95ab PG	2	* AR71xx Reset Controller Driver
	3	* Author: Alban Bedel
	4	*
ff591a91 AB	5	* Copyright (C) 2015 Alban Bedel <albeu@free.fr>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*/
	17
9e9ba091	18	#include <linux/io.h>
90ce95ab	19	#include <linux/init.h>
ff591a91 AB	20	#include <linux/platform_device.h>
ff591a91 AB	21	#include <linux/reset-controller.h>
ba64e27e	22	#include <linux/reboot.h>
ff591a91 AB	23
	24	struct ath79_reset {
	25	struct reset_controller_dev rcdev;
ba64e27e	26	struct notifier_block restart_nb;
ff591a91 AB	27	void __iomem *base;
	28	spinlock_t lock;
	29	};
	30
ba64e27e AB	31	#define FULL_CHIP_RESET 24
ba64e27e AB	32
ff591a91 AB	33	static int ath79_reset_update(struct reset_controller_dev *rcdev,
	34	unsigned long id, bool assert)
	35	{
	36	struct ath79_reset *ath79_reset =
	37	container_of(rcdev, struct ath79_reset, rcdev);
	38	unsigned long flags;
	39	u32 val;
	40
	41	spin_lock_irqsave(&ath79_reset->lock, flags);
	42	val = readl(ath79_reset->base);
	43	if (assert)
	44	val \|= BIT(id);
	45	else
	46	val &= ~BIT(id);
	47	writel(val, ath79_reset->base);
	48	spin_unlock_irqrestore(&ath79_reset->lock, flags);
	49
	50	return 0;
	51	}
	52
	53	static int ath79_reset_assert(struct reset_controller_dev *rcdev,
	54	unsigned long id)
	55	{
	56	return ath79_reset_update(rcdev, id, true);
	57	}
	58
	59	static int ath79_reset_deassert(struct reset_controller_dev *rcdev,
	60	unsigned long id)
	61	{
	62	return ath79_reset_update(rcdev, id, false);
	63	}
	64
	65	static int ath79_reset_status(struct reset_controller_dev *rcdev,
	66	unsigned long id)
	67	{
	68	struct ath79_reset *ath79_reset =
	69	container_of(rcdev, struct ath79_reset, rcdev);
	70	u32 val;
	71
	72	val = readl(ath79_reset->base);
	73
	74	return !!(val & BIT(id));
	75	}
	76
d2f79f22	77	static const struct reset_control_ops ath79_reset_ops = {
ff591a91 AB	78	.assert = ath79_reset_assert,
	79	.deassert = ath79_reset_deassert,
	80	.status = ath79_reset_status,
	81	};
	82
ba64e27e AB	83	static int ath79_reset_restart_handler(struct notifier_block *nb,
	84	unsigned long action, void *data)
	85	{
	86	struct ath79_reset *ath79_reset =
	87	container_of(nb, struct ath79_reset, restart_nb);
	88
	89	ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);
	90
	91	return NOTIFY_DONE;
	92	}
	93
ff591a91 AB	94	static int ath79_reset_probe(struct platform_device *pdev)
	95	{
	96	struct ath79_reset *ath79_reset;
	97	struct resource *res;
ba64e27e	98	int err;
ff591a91 AB	99
	100	ath79_reset = devm_kzalloc(&pdev->dev,
	101	sizeof(*ath79_reset), GFP_KERNEL);
	102	if (!ath79_reset)
	103	return -ENOMEM;
	104
	105	platform_set_drvdata(pdev, ath79_reset);
	106
	107	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	108	ath79_reset->base = devm_ioremap_resource(&pdev->dev, res);
	109	if (IS_ERR(ath79_reset->base))
	110	return PTR_ERR(ath79_reset->base);
	111
f319cb84	112	spin_lock_init(&ath79_reset->lock);
ff591a91 AB	113	ath79_reset->rcdev.ops = &ath79_reset_ops;
	114	ath79_reset->rcdev.owner = THIS_MODULE;
	115	ath79_reset->rcdev.of_node = pdev->dev.of_node;
	116	ath79_reset->rcdev.of_reset_n_cells = 1;
	117	ath79_reset->rcdev.nr_resets = 32;
	118
56865f45	119	err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev);
ba64e27e AB	120	if (err)
	121	return err;
	122
	123	ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler;
	124	ath79_reset->restart_nb.priority = 128;
	125
	126	err = register_restart_handler(&ath79_reset->restart_nb);
	127	if (err)
	128	dev_warn(&pdev->dev, "Failed to register restart handler\n");
	129
	130	return 0;
ff591a91 AB	131	}
ff591a91 AB	132
ff591a91 AB	133	static const struct of_device_id ath79_reset_dt_ids[] = {
	134	{ .compatible = "qca,ar7100-reset", },
	135	{ },
	136	};
ff591a91 AB	137
	138	static struct platform_driver ath79_reset_driver = {
	139	.probe = ath79_reset_probe,
ff591a91	140	.driver = {
90ce95ab PG	141	.name = "ath79-reset",
	142	.of_match_table = ath79_reset_dt_ids,
	143	.suppress_bind_attrs = true,
ff591a91 AB	144	},
ff591a91 AB	145	};
90ce95ab	146	builtin_platform_driver(ath79_reset_driver);