[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/mod_devicetable.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>
ac316725	20	#include <linux/mod_devicetable.h>
ff591a91 AB	21	#include <linux/platform_device.h>
ff591a91 AB	22	#include <linux/reset-controller.h>
ba64e27e	23	#include <linux/reboot.h>
ff591a91 AB	24
	25	struct ath79_reset {
	26	struct reset_controller_dev rcdev;
ba64e27e	27	struct notifier_block restart_nb;
ff591a91 AB	28	void __iomem *base;
	29	spinlock_t lock;
	30	};
	31
ba64e27e AB	32	#define FULL_CHIP_RESET 24
ba64e27e AB	33
ff591a91 AB	34	static int ath79_reset_update(struct reset_controller_dev *rcdev,
	35	unsigned long id, bool assert)
	36	{
	37	struct ath79_reset *ath79_reset =
	38	container_of(rcdev, struct ath79_reset, rcdev);
	39	unsigned long flags;
	40	u32 val;
	41
	42	spin_lock_irqsave(&ath79_reset->lock, flags);
	43	val = readl(ath79_reset->base);
	44	if (assert)
	45	val \|= BIT(id);
	46	else
	47	val &= ~BIT(id);
	48	writel(val, ath79_reset->base);
	49	spin_unlock_irqrestore(&ath79_reset->lock, flags);
	50
	51	return 0;
	52	}
	53
	54	static int ath79_reset_assert(struct reset_controller_dev *rcdev,
	55	unsigned long id)
	56	{
	57	return ath79_reset_update(rcdev, id, true);
	58	}
	59
	60	static int ath79_reset_deassert(struct reset_controller_dev *rcdev,
	61	unsigned long id)
	62	{
	63	return ath79_reset_update(rcdev, id, false);
	64	}
	65
	66	static int ath79_reset_status(struct reset_controller_dev *rcdev,
	67	unsigned long id)
	68	{
	69	struct ath79_reset *ath79_reset =
	70	container_of(rcdev, struct ath79_reset, rcdev);
	71	u32 val;
	72
	73	val = readl(ath79_reset->base);
	74
	75	return !!(val & BIT(id));
	76	}
	77
d2f79f22	78	static const struct reset_control_ops ath79_reset_ops = {
ff591a91 AB	79	.assert = ath79_reset_assert,
	80	.deassert = ath79_reset_deassert,
	81	.status = ath79_reset_status,
	82	};
	83
ba64e27e AB	84	static int ath79_reset_restart_handler(struct notifier_block *nb,
	85	unsigned long action, void *data)
	86	{
	87	struct ath79_reset *ath79_reset =
	88	container_of(nb, struct ath79_reset, restart_nb);
	89
	90	ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);
	91
	92	return NOTIFY_DONE;
	93	}
	94
ff591a91 AB	95	static int ath79_reset_probe(struct platform_device *pdev)
	96	{
	97	struct ath79_reset *ath79_reset;
	98	struct resource *res;
ba64e27e	99	int err;
ff591a91 AB	100
	101	ath79_reset = devm_kzalloc(&pdev->dev,
	102	sizeof(*ath79_reset), GFP_KERNEL);
	103	if (!ath79_reset)
	104	return -ENOMEM;
	105
	106	platform_set_drvdata(pdev, ath79_reset);
	107
	108	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	109	ath79_reset->base = devm_ioremap_resource(&pdev->dev, res);
	110	if (IS_ERR(ath79_reset->base))
	111	return PTR_ERR(ath79_reset->base);
	112
f319cb84	113	spin_lock_init(&ath79_reset->lock);
ff591a91 AB	114	ath79_reset->rcdev.ops = &ath79_reset_ops;
	115	ath79_reset->rcdev.owner = THIS_MODULE;
	116	ath79_reset->rcdev.of_node = pdev->dev.of_node;
	117	ath79_reset->rcdev.of_reset_n_cells = 1;
	118	ath79_reset->rcdev.nr_resets = 32;
	119
56865f45	120	err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev);
ba64e27e AB	121	if (err)
	122	return err;
	123
	124	ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler;
	125	ath79_reset->restart_nb.priority = 128;
	126
	127	err = register_restart_handler(&ath79_reset->restart_nb);
	128	if (err)
	129	dev_warn(&pdev->dev, "Failed to register restart handler\n");
	130
	131	return 0;
ff591a91 AB	132	}
ff591a91 AB	133
ff591a91 AB	134	static const struct of_device_id ath79_reset_dt_ids[] = {
	135	{ .compatible = "qca,ar7100-reset", },
	136	{ },
	137	};
ff591a91 AB	138
	139	static struct platform_driver ath79_reset_driver = {
	140	.probe = ath79_reset_probe,
ff591a91	141	.driver = {
90ce95ab PG	142	.name = "ath79-reset",
	143	.of_match_table = ath79_reset_dt_ids,
	144	.suppress_bind_attrs = true,
ff591a91 AB	145	},
ff591a91 AB	146	};
90ce95ab	147	builtin_platform_driver(ath79_reset_driver);