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v5.9
  1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
  2/*
  3 * Amlogic Meson Reset Controller driver
  4 *
  5 * Copyright (c) 2016 BayLibre, SAS.
  6 * Author: Neil Armstrong <narmstrong@baylibre.com>
  7 */
  8#include <linux/err.h>
  9#include <linux/init.h>
 10#include <linux/io.h>
 11#include <linux/of.h>
 
 12#include <linux/platform_device.h>
 13#include <linux/reset-controller.h>
 14#include <linux/slab.h>
 15#include <linux/types.h>
 16#include <linux/of_device.h>
 17
 18#define BITS_PER_REG	32
 19
 20struct meson_reset_param {
 21	int reg_count;
 22	int level_offset;
 23};
 24
 25struct meson_reset {
 26	void __iomem *reg_base;
 27	const struct meson_reset_param *param;
 28	struct reset_controller_dev rcdev;
 29	spinlock_t lock;
 30};
 31
 32static int meson_reset_reset(struct reset_controller_dev *rcdev,
 33			      unsigned long id)
 34{
 35	struct meson_reset *data =
 36		container_of(rcdev, struct meson_reset, rcdev);
 37	unsigned int bank = id / BITS_PER_REG;
 38	unsigned int offset = id % BITS_PER_REG;
 39	void __iomem *reg_addr = data->reg_base + (bank << 2);
 40
 41	writel(BIT(offset), reg_addr);
 42
 43	return 0;
 44}
 45
 46static int meson_reset_level(struct reset_controller_dev *rcdev,
 47			    unsigned long id, bool assert)
 48{
 49	struct meson_reset *data =
 50		container_of(rcdev, struct meson_reset, rcdev);
 51	unsigned int bank = id / BITS_PER_REG;
 52	unsigned int offset = id % BITS_PER_REG;
 53	void __iomem *reg_addr;
 54	unsigned long flags;
 55	u32 reg;
 56
 57	reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
 58
 59	spin_lock_irqsave(&data->lock, flags);
 60
 61	reg = readl(reg_addr);
 62	if (assert)
 63		writel(reg & ~BIT(offset), reg_addr);
 64	else
 65		writel(reg | BIT(offset), reg_addr);
 66
 67	spin_unlock_irqrestore(&data->lock, flags);
 68
 69	return 0;
 70}
 71
 72static int meson_reset_assert(struct reset_controller_dev *rcdev,
 73			      unsigned long id)
 74{
 75	return meson_reset_level(rcdev, id, true);
 76}
 77
 78static int meson_reset_deassert(struct reset_controller_dev *rcdev,
 79				unsigned long id)
 80{
 81	return meson_reset_level(rcdev, id, false);
 82}
 83
 84static const struct reset_control_ops meson_reset_ops = {
 85	.reset		= meson_reset_reset,
 86	.assert		= meson_reset_assert,
 87	.deassert	= meson_reset_deassert,
 88};
 89
 90static const struct meson_reset_param meson8b_param = {
 91	.reg_count	= 8,
 92	.level_offset	= 0x7c,
 93};
 94
 95static const struct meson_reset_param meson_a1_param = {
 96	.reg_count	= 3,
 97	.level_offset	= 0x40,
 98};
 99
 
 
 
 
 
100static const struct of_device_id meson_reset_dt_ids[] = {
101	 { .compatible = "amlogic,meson8b-reset",    .data = &meson8b_param},
102	 { .compatible = "amlogic,meson-gxbb-reset", .data = &meson8b_param},
103	 { .compatible = "amlogic,meson-axg-reset",  .data = &meson8b_param},
104	 { .compatible = "amlogic,meson-a1-reset",   .data = &meson_a1_param},
 
105	 { /* sentinel */ },
106};
 
107
108static int meson_reset_probe(struct platform_device *pdev)
109{
110	struct meson_reset *data;
111	struct resource *res;
112
113	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
114	if (!data)
115		return -ENOMEM;
116
117	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
118	data->reg_base = devm_ioremap_resource(&pdev->dev, res);
119	if (IS_ERR(data->reg_base))
120		return PTR_ERR(data->reg_base);
121
122	data->param = of_device_get_match_data(&pdev->dev);
123	if (!data->param)
124		return -ENODEV;
125
126	platform_set_drvdata(pdev, data);
127
128	spin_lock_init(&data->lock);
129
130	data->rcdev.owner = THIS_MODULE;
131	data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG;
132	data->rcdev.ops = &meson_reset_ops;
133	data->rcdev.of_node = pdev->dev.of_node;
134
135	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
136}
137
138static struct platform_driver meson_reset_driver = {
139	.probe	= meson_reset_probe,
140	.driver = {
141		.name		= "meson_reset",
142		.of_match_table	= meson_reset_dt_ids,
143	},
144};
145builtin_platform_driver(meson_reset_driver);
 
 
 
 
v6.2
  1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
  2/*
  3 * Amlogic Meson Reset Controller driver
  4 *
  5 * Copyright (c) 2016 BayLibre, SAS.
  6 * Author: Neil Armstrong <narmstrong@baylibre.com>
  7 */
  8#include <linux/err.h>
  9#include <linux/init.h>
 10#include <linux/io.h>
 11#include <linux/of.h>
 12#include <linux/module.h>
 13#include <linux/platform_device.h>
 14#include <linux/reset-controller.h>
 15#include <linux/slab.h>
 16#include <linux/types.h>
 17#include <linux/of_device.h>
 18
 19#define BITS_PER_REG	32
 20
 21struct meson_reset_param {
 22	int reg_count;
 23	int level_offset;
 24};
 25
 26struct meson_reset {
 27	void __iomem *reg_base;
 28	const struct meson_reset_param *param;
 29	struct reset_controller_dev rcdev;
 30	spinlock_t lock;
 31};
 32
 33static int meson_reset_reset(struct reset_controller_dev *rcdev,
 34			      unsigned long id)
 35{
 36	struct meson_reset *data =
 37		container_of(rcdev, struct meson_reset, rcdev);
 38	unsigned int bank = id / BITS_PER_REG;
 39	unsigned int offset = id % BITS_PER_REG;
 40	void __iomem *reg_addr = data->reg_base + (bank << 2);
 41
 42	writel(BIT(offset), reg_addr);
 43
 44	return 0;
 45}
 46
 47static int meson_reset_level(struct reset_controller_dev *rcdev,
 48			    unsigned long id, bool assert)
 49{
 50	struct meson_reset *data =
 51		container_of(rcdev, struct meson_reset, rcdev);
 52	unsigned int bank = id / BITS_PER_REG;
 53	unsigned int offset = id % BITS_PER_REG;
 54	void __iomem *reg_addr;
 55	unsigned long flags;
 56	u32 reg;
 57
 58	reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
 59
 60	spin_lock_irqsave(&data->lock, flags);
 61
 62	reg = readl(reg_addr);
 63	if (assert)
 64		writel(reg & ~BIT(offset), reg_addr);
 65	else
 66		writel(reg | BIT(offset), reg_addr);
 67
 68	spin_unlock_irqrestore(&data->lock, flags);
 69
 70	return 0;
 71}
 72
 73static int meson_reset_assert(struct reset_controller_dev *rcdev,
 74			      unsigned long id)
 75{
 76	return meson_reset_level(rcdev, id, true);
 77}
 78
 79static int meson_reset_deassert(struct reset_controller_dev *rcdev,
 80				unsigned long id)
 81{
 82	return meson_reset_level(rcdev, id, false);
 83}
 84
 85static const struct reset_control_ops meson_reset_ops = {
 86	.reset		= meson_reset_reset,
 87	.assert		= meson_reset_assert,
 88	.deassert	= meson_reset_deassert,
 89};
 90
 91static const struct meson_reset_param meson8b_param = {
 92	.reg_count	= 8,
 93	.level_offset	= 0x7c,
 94};
 95
 96static const struct meson_reset_param meson_a1_param = {
 97	.reg_count	= 3,
 98	.level_offset	= 0x40,
 99};
100
101static const struct meson_reset_param meson_s4_param = {
102	.reg_count	= 6,
103	.level_offset	= 0x40,
104};
105
106static const struct of_device_id meson_reset_dt_ids[] = {
107	 { .compatible = "amlogic,meson8b-reset",    .data = &meson8b_param},
108	 { .compatible = "amlogic,meson-gxbb-reset", .data = &meson8b_param},
109	 { .compatible = "amlogic,meson-axg-reset",  .data = &meson8b_param},
110	 { .compatible = "amlogic,meson-a1-reset",   .data = &meson_a1_param},
111	 { .compatible = "amlogic,meson-s4-reset",   .data = &meson_s4_param},
112	 { /* sentinel */ },
113};
114MODULE_DEVICE_TABLE(of, meson_reset_dt_ids);
115
116static int meson_reset_probe(struct platform_device *pdev)
117{
118	struct meson_reset *data;
119	struct resource *res;
120
121	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
122	if (!data)
123		return -ENOMEM;
124
125	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
126	data->reg_base = devm_ioremap_resource(&pdev->dev, res);
127	if (IS_ERR(data->reg_base))
128		return PTR_ERR(data->reg_base);
129
130	data->param = of_device_get_match_data(&pdev->dev);
131	if (!data->param)
132		return -ENODEV;
133
134	platform_set_drvdata(pdev, data);
135
136	spin_lock_init(&data->lock);
137
138	data->rcdev.owner = THIS_MODULE;
139	data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG;
140	data->rcdev.ops = &meson_reset_ops;
141	data->rcdev.of_node = pdev->dev.of_node;
142
143	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
144}
145
146static struct platform_driver meson_reset_driver = {
147	.probe	= meson_reset_probe,
148	.driver = {
149		.name		= "meson_reset",
150		.of_match_table	= meson_reset_dt_ids,
151	},
152};
153module_platform_driver(meson_reset_driver);
154
155MODULE_DESCRIPTION("Amlogic Meson Reset Controller driver");
156MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
157MODULE_LICENSE("Dual BSD/GPL");