116 строки
2.8 KiB
C
116 строки
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) STMicroelectronics 2018 - All Rights Reserved
|
|
* Author: Gabriel Fernandez <gabriel.fernandez@st.com> for STMicroelectronics.
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include <linux/err.h>
|
|
#include <linux/io.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/reset-controller.h>
|
|
|
|
#define CLR_OFFSET 0x4
|
|
|
|
struct stm32_reset_data {
|
|
struct reset_controller_dev rcdev;
|
|
void __iomem *membase;
|
|
};
|
|
|
|
static inline struct stm32_reset_data *
|
|
to_stm32_reset_data(struct reset_controller_dev *rcdev)
|
|
{
|
|
return container_of(rcdev, struct stm32_reset_data, rcdev);
|
|
}
|
|
|
|
static int stm32_reset_update(struct reset_controller_dev *rcdev,
|
|
unsigned long id, bool assert)
|
|
{
|
|
struct stm32_reset_data *data = to_stm32_reset_data(rcdev);
|
|
int reg_width = sizeof(u32);
|
|
int bank = id / (reg_width * BITS_PER_BYTE);
|
|
int offset = id % (reg_width * BITS_PER_BYTE);
|
|
void __iomem *addr;
|
|
|
|
addr = data->membase + (bank * reg_width);
|
|
if (!assert)
|
|
addr += CLR_OFFSET;
|
|
|
|
writel(BIT(offset), addr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_reset_assert(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
return stm32_reset_update(rcdev, id, true);
|
|
}
|
|
|
|
static int stm32_reset_deassert(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
return stm32_reset_update(rcdev, id, false);
|
|
}
|
|
|
|
static int stm32_reset_status(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
struct stm32_reset_data *data = to_stm32_reset_data(rcdev);
|
|
int reg_width = sizeof(u32);
|
|
int bank = id / (reg_width * BITS_PER_BYTE);
|
|
int offset = id % (reg_width * BITS_PER_BYTE);
|
|
u32 reg;
|
|
|
|
reg = readl(data->membase + (bank * reg_width));
|
|
|
|
return !!(reg & BIT(offset));
|
|
}
|
|
|
|
static const struct reset_control_ops stm32_reset_ops = {
|
|
.assert = stm32_reset_assert,
|
|
.deassert = stm32_reset_deassert,
|
|
.status = stm32_reset_status,
|
|
};
|
|
|
|
static const struct of_device_id stm32_reset_dt_ids[] = {
|
|
{ .compatible = "st,stm32mp1-rcc"},
|
|
{ /* sentinel */ },
|
|
};
|
|
|
|
static int stm32_reset_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct stm32_reset_data *data;
|
|
void __iomem *membase;
|
|
struct resource *res;
|
|
|
|
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
membase = devm_ioremap_resource(dev, res);
|
|
if (IS_ERR(membase))
|
|
return PTR_ERR(membase);
|
|
|
|
data->membase = membase;
|
|
data->rcdev.owner = THIS_MODULE;
|
|
data->rcdev.nr_resets = resource_size(res) * BITS_PER_BYTE;
|
|
data->rcdev.ops = &stm32_reset_ops;
|
|
data->rcdev.of_node = dev->of_node;
|
|
|
|
return devm_reset_controller_register(dev, &data->rcdev);
|
|
}
|
|
|
|
static struct platform_driver stm32_reset_driver = {
|
|
.probe = stm32_reset_probe,
|
|
.driver = {
|
|
.name = "stm32mp1-reset",
|
|
.of_match_table = stm32_reset_dt_ids,
|
|
},
|
|
};
|
|
|
|
builtin_platform_driver(stm32_reset_driver);
|