linuxdebug/drivers/clk/visconti/reset.c

108 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Toshiba Visconti ARM SoC reset controller
*
* Copyright (c) 2021 TOSHIBA CORPORATION
* Copyright (c) 2021 Toshiba Electronic Devices & Storage Corporation
*
* Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include "reset.h"
static inline struct visconti_reset *to_visconti_reset(struct reset_controller_dev *rcdev)
{
return container_of(rcdev, struct visconti_reset, rcdev);
}
static int visconti_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
{
struct visconti_reset *reset = to_visconti_reset(rcdev);
const struct visconti_reset_data *data = &reset->resets[id];
u32 rst = BIT(data->rs_idx);
unsigned long flags;
int ret;
spin_lock_irqsave(reset->lock, flags);
ret = regmap_update_bits(reset->regmap, data->rson_offset, rst, rst);
spin_unlock_irqrestore(reset->lock, flags);
return ret;
}
static int visconti_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
{
struct visconti_reset *reset = to_visconti_reset(rcdev);
const struct visconti_reset_data *data = &reset->resets[id];
u32 rst = BIT(data->rs_idx);
unsigned long flags;
int ret;
spin_lock_irqsave(reset->lock, flags);
ret = regmap_update_bits(reset->regmap, data->rsoff_offset, rst, rst);
spin_unlock_irqrestore(reset->lock, flags);
return ret;
}
static int visconti_reset_reset(struct reset_controller_dev *rcdev, unsigned long id)
{
visconti_reset_assert(rcdev, id);
udelay(1);
visconti_reset_deassert(rcdev, id);
return 0;
}
static int visconti_reset_status(struct reset_controller_dev *rcdev, unsigned long id)
{
struct visconti_reset *reset = to_visconti_reset(rcdev);
const struct visconti_reset_data *data = &reset->resets[id];
unsigned long flags;
u32 reg;
int ret;
spin_lock_irqsave(reset->lock, flags);
ret = regmap_read(reset->regmap, data->rson_offset, &reg);
spin_unlock_irqrestore(reset->lock, flags);
if (ret)
return ret;
return !(reg & data->rs_idx);
}
const struct reset_control_ops visconti_reset_ops = {
.assert = visconti_reset_assert,
.deassert = visconti_reset_deassert,
.reset = visconti_reset_reset,
.status = visconti_reset_status,
};
int visconti_register_reset_controller(struct device *dev,
struct regmap *regmap,
const struct visconti_reset_data *resets,
unsigned int num_resets,
const struct reset_control_ops *reset_ops,
spinlock_t *lock)
{
struct visconti_reset *reset;
reset = devm_kzalloc(dev, sizeof(*reset), GFP_KERNEL);
if (!reset)
return -ENOMEM;
reset->regmap = regmap;
reset->resets = resets;
reset->rcdev.ops = reset_ops;
reset->rcdev.nr_resets = num_resets;
reset->rcdev.of_node = dev->of_node;
reset->lock = lock;
return devm_reset_controller_register(dev, &reset->rcdev);
}