linux/linux-5.4.31/drivers/clk/actions/owl-reset.c

67 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
//
// Actions Semi Owl SoCs Reset Management Unit driver
//
// Copyright (c) 2018 Linaro Ltd.
// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
#include <linux/delay.h>
#include <linux/regmap.h>
#include <linux/reset-controller.h>
#include "owl-reset.h"
static int owl_reset_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct owl_reset *reset = to_owl_reset(rcdev);
const struct owl_reset_map *map = &reset->reset_map[id];
return regmap_update_bits(reset->regmap, map->reg, map->bit, 0);
}
static int owl_reset_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct owl_reset *reset = to_owl_reset(rcdev);
const struct owl_reset_map *map = &reset->reset_map[id];
return regmap_update_bits(reset->regmap, map->reg, map->bit, map->bit);
}
static int owl_reset_reset(struct reset_controller_dev *rcdev,
unsigned long id)
{
owl_reset_assert(rcdev, id);
udelay(1);
owl_reset_deassert(rcdev, id);
return 0;
}
static int owl_reset_status(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct owl_reset *reset = to_owl_reset(rcdev);
const struct owl_reset_map *map = &reset->reset_map[id];
u32 reg;
int ret;
ret = regmap_read(reset->regmap, map->reg, &reg);
if (ret)
return ret;
/*
* The reset control API expects 0 if reset is not asserted,
* which is the opposite of what our hardware uses.
*/
return !(map->bit & reg);
}
const struct reset_control_ops owl_reset_ops = {
.assert = owl_reset_assert,
.deassert = owl_reset_deassert,
.reset = owl_reset_reset,
.status = owl_reset_status,
};