158 lines
4.0 KiB
C
158 lines
4.0 KiB
C
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
|
|
/*
|
|
* Amlogic Meson Reset Controller driver
|
|
*
|
|
* Copyright (c) 2016 BayLibre, SAS.
|
|
* Author: Neil Armstrong <narmstrong@baylibre.com>
|
|
*/
|
|
#include <linux/err.h>
|
|
#include <linux/init.h>
|
|
#include <linux/io.h>
|
|
#include <linux/of.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/reset-controller.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/types.h>
|
|
#include <linux/of_device.h>
|
|
|
|
#define BITS_PER_REG 32
|
|
|
|
struct meson_reset_param {
|
|
int reg_count;
|
|
int level_offset;
|
|
};
|
|
|
|
struct meson_reset {
|
|
void __iomem *reg_base;
|
|
const struct meson_reset_param *param;
|
|
struct reset_controller_dev rcdev;
|
|
spinlock_t lock;
|
|
};
|
|
|
|
static int meson_reset_reset(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
struct meson_reset *data =
|
|
container_of(rcdev, struct meson_reset, rcdev);
|
|
unsigned int bank = id / BITS_PER_REG;
|
|
unsigned int offset = id % BITS_PER_REG;
|
|
void __iomem *reg_addr = data->reg_base + (bank << 2);
|
|
|
|
writel(BIT(offset), reg_addr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int meson_reset_level(struct reset_controller_dev *rcdev,
|
|
unsigned long id, bool assert)
|
|
{
|
|
struct meson_reset *data =
|
|
container_of(rcdev, struct meson_reset, rcdev);
|
|
unsigned int bank = id / BITS_PER_REG;
|
|
unsigned int offset = id % BITS_PER_REG;
|
|
void __iomem *reg_addr;
|
|
unsigned long flags;
|
|
u32 reg;
|
|
|
|
reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
|
|
|
|
spin_lock_irqsave(&data->lock, flags);
|
|
|
|
reg = readl(reg_addr);
|
|
if (assert)
|
|
writel(reg & ~BIT(offset), reg_addr);
|
|
else
|
|
writel(reg | BIT(offset), reg_addr);
|
|
|
|
spin_unlock_irqrestore(&data->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int meson_reset_assert(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
return meson_reset_level(rcdev, id, true);
|
|
}
|
|
|
|
static int meson_reset_deassert(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
return meson_reset_level(rcdev, id, false);
|
|
}
|
|
|
|
static const struct reset_control_ops meson_reset_ops = {
|
|
.reset = meson_reset_reset,
|
|
.assert = meson_reset_assert,
|
|
.deassert = meson_reset_deassert,
|
|
};
|
|
|
|
static const struct meson_reset_param meson8b_param = {
|
|
.reg_count = 8,
|
|
.level_offset = 0x7c,
|
|
};
|
|
|
|
static const struct meson_reset_param meson_a1_param = {
|
|
.reg_count = 3,
|
|
.level_offset = 0x40,
|
|
};
|
|
|
|
static const struct meson_reset_param meson_s4_param = {
|
|
.reg_count = 6,
|
|
.level_offset = 0x40,
|
|
};
|
|
|
|
static const struct of_device_id meson_reset_dt_ids[] = {
|
|
{ .compatible = "amlogic,meson8b-reset", .data = &meson8b_param},
|
|
{ .compatible = "amlogic,meson-gxbb-reset", .data = &meson8b_param},
|
|
{ .compatible = "amlogic,meson-axg-reset", .data = &meson8b_param},
|
|
{ .compatible = "amlogic,meson-a1-reset", .data = &meson_a1_param},
|
|
{ .compatible = "amlogic,meson-s4-reset", .data = &meson_s4_param},
|
|
{ /* sentinel */ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, meson_reset_dt_ids);
|
|
|
|
static int meson_reset_probe(struct platform_device *pdev)
|
|
{
|
|
struct meson_reset *data;
|
|
struct resource *res;
|
|
|
|
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
data->reg_base = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(data->reg_base))
|
|
return PTR_ERR(data->reg_base);
|
|
|
|
data->param = of_device_get_match_data(&pdev->dev);
|
|
if (!data->param)
|
|
return -ENODEV;
|
|
|
|
platform_set_drvdata(pdev, data);
|
|
|
|
spin_lock_init(&data->lock);
|
|
|
|
data->rcdev.owner = THIS_MODULE;
|
|
data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG;
|
|
data->rcdev.ops = &meson_reset_ops;
|
|
data->rcdev.of_node = pdev->dev.of_node;
|
|
|
|
return devm_reset_controller_register(&pdev->dev, &data->rcdev);
|
|
}
|
|
|
|
static struct platform_driver meson_reset_driver = {
|
|
.probe = meson_reset_probe,
|
|
.driver = {
|
|
.name = "meson_reset",
|
|
.of_match_table = meson_reset_dt_ids,
|
|
},
|
|
};
|
|
module_platform_driver(meson_reset_driver);
|
|
|
|
MODULE_DESCRIPTION("Amlogic Meson Reset Controller driver");
|
|
MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
|
|
MODULE_LICENSE("Dual BSD/GPL");
|