linux/drivers/clk/mediatek/reset.c

98 lines
2.3 KiB
C

/*
* Copyright (c) 2014 MediaTek Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset-controller.h>
#include <linux/slab.h>
#include "clk-mtk.h"
struct mtk_reset {
struct regmap *regmap;
int regofs;
struct reset_controller_dev rcdev;
};
static int mtk_reset_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
return regmap_update_bits(data->regmap, data->regofs + ((id / 32) << 2),
BIT(id % 32), ~0);
}
static int mtk_reset_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
return regmap_update_bits(data->regmap, data->regofs + ((id / 32) << 2),
BIT(id % 32), 0);
}
static int mtk_reset(struct reset_controller_dev *rcdev,
unsigned long id)
{
int ret;
ret = mtk_reset_assert(rcdev, id);
if (ret)
return ret;
return mtk_reset_deassert(rcdev, id);
}
static struct reset_control_ops mtk_reset_ops = {
.assert = mtk_reset_assert,
.deassert = mtk_reset_deassert,
.reset = mtk_reset,
};
void mtk_register_reset_controller(struct device_node *np,
unsigned int num_regs, int regofs)
{
struct mtk_reset *data;
int ret;
struct regmap *regmap;
regmap = syscon_node_to_regmap(np);
if (IS_ERR(regmap)) {
pr_err("Cannot find regmap for %s: %ld\n", np->full_name,
PTR_ERR(regmap));
return;
}
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return;
data->regmap = regmap;
data->regofs = regofs;
data->rcdev.owner = THIS_MODULE;
data->rcdev.nr_resets = num_regs * 32;
data->rcdev.ops = &mtk_reset_ops;
data->rcdev.of_node = np;
ret = reset_controller_register(&data->rcdev);
if (ret) {
pr_err("could not register reset controller: %d\n", ret);
kfree(data);
return;
}
}