143 lines
3.4 KiB
C
143 lines
3.4 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 <dt-bindings/reset/stm32mp1-resets.h>
|
|
#include <linux/arm-smccc.h>
|
|
#include <linux/device.h>
|
|
#include <linux/err.h>
|
|
#include <linux/io.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/reset-controller.h>
|
|
#include <linux/slab.h>
|
|
|
|
#define STM32MP1_RESET_ID_MASK GENMASK(15, 0)
|
|
|
|
#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 void __init stm32mp1_reset_init(struct device_node *np)
|
|
{
|
|
void __iomem *base;
|
|
const struct of_device_id *match;
|
|
struct stm32_reset_data *data = NULL;
|
|
int ret;
|
|
|
|
base = of_iomap(np, 0);
|
|
if (!base) {
|
|
pr_err("%pOFn: unable to map resource", np);
|
|
of_node_put(np);
|
|
return;
|
|
}
|
|
|
|
match = of_match_node(stm32_reset_dt_ids, np);
|
|
if (!match) {
|
|
pr_err("%s: match data not found\n", __func__);
|
|
goto err;
|
|
}
|
|
|
|
data = kzalloc(sizeof(*data), GFP_KERNEL);
|
|
if (!data)
|
|
goto err;
|
|
|
|
data->membase = base;
|
|
data->rcdev.owner = THIS_MODULE;
|
|
data->rcdev.ops = &stm32_reset_ops;
|
|
data->rcdev.of_node = np;
|
|
data->rcdev.nr_resets = STM32MP1_RESET_ID_MASK;
|
|
|
|
ret = reset_controller_register(&data->rcdev);
|
|
if (!ret)
|
|
return;
|
|
|
|
err:
|
|
pr_err("stm32mp1 reset failed to initialize\n");
|
|
if (data)
|
|
kfree(data);
|
|
if (base)
|
|
iounmap(base);
|
|
of_node_put(np);
|
|
}
|
|
|
|
/*
|
|
* RCC reset and clock drivers bind to the same RCC node.
|
|
* Register RCC reset driver at init through clock of table,
|
|
* clock driver for RCC will register at probe time.
|
|
*/
|
|
static void __init stm32mp1_reset_of_init_drv(struct device_node *np)
|
|
{
|
|
of_node_clear_flag(np, OF_POPULATED);
|
|
stm32mp1_reset_init(np);
|
|
}
|
|
OF_DECLARE_1(clk, stm32mp1_rcc, "st,stm32mp1-rcc", stm32mp1_reset_of_init_drv);
|