linux_dsm_epyc7002/drivers/reset/reset-oxnas.c
Neil Armstrong 6e667fac82 reset: Add Oxford Semiconductor Reset Controller driver
Add System reset controller driver for Oxford Semiconductor OXNAS SoC
Family.

CC: Ma Haijun <mahaijuns@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-04-01 16:31:09 +02:00

137 lines
3.4 KiB
C

/*
* drivers/reset/reset-oxnas.c
*
* Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
* Copyright (C) 2014 Ma Haijun <mahaijuns@gmail.com>
* Copyright (C) 2009 Oxford Semiconductor Ltd
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
/* Regmap offsets */
#define RST_SET_REGOFFSET 0x34
#define RST_CLR_REGOFFSET 0x38
struct oxnas_reset {
struct regmap *regmap;
struct reset_controller_dev rcdev;
};
static int oxnas_reset_reset(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct oxnas_reset *data =
container_of(rcdev, struct oxnas_reset, rcdev);
regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
msleep(50);
regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
return 0;
}
static int oxnas_reset_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct oxnas_reset *data =
container_of(rcdev, struct oxnas_reset, rcdev);
regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
return 0;
}
static int oxnas_reset_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct oxnas_reset *data =
container_of(rcdev, struct oxnas_reset, rcdev);
regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
return 0;
}
static const struct reset_control_ops oxnas_reset_ops = {
.reset = oxnas_reset_reset,
.assert = oxnas_reset_assert,
.deassert = oxnas_reset_deassert,
};
static const struct of_device_id oxnas_reset_dt_ids[] = {
{ .compatible = "oxsemi,ox810se-reset", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, oxnas_reset_dt_ids);
static int oxnas_reset_probe(struct platform_device *pdev)
{
struct oxnas_reset *data;
struct device *parent;
parent = pdev->dev.parent;
if (!parent) {
dev_err(&pdev->dev, "no parent\n");
return -ENODEV;
}
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->regmap = syscon_node_to_regmap(parent->of_node);
if (IS_ERR(data->regmap)) {
dev_err(&pdev->dev, "failed to get parent regmap\n");
return PTR_ERR(data->regmap);
}
platform_set_drvdata(pdev, data);
data->rcdev.owner = THIS_MODULE;
data->rcdev.nr_resets = 32;
data->rcdev.ops = &oxnas_reset_ops;
data->rcdev.of_node = pdev->dev.of_node;
return reset_controller_register(&data->rcdev);
}
static int oxnas_reset_remove(struct platform_device *pdev)
{
struct oxnas_reset *data = platform_get_drvdata(pdev);
reset_controller_unregister(&data->rcdev);
return 0;
}
static struct platform_driver oxnas_reset_driver = {
.probe = oxnas_reset_probe,
.remove = oxnas_reset_remove,
.driver = {
.name = "oxnas-reset",
.of_match_table = oxnas_reset_dt_ids,
},
};
module_platform_driver(oxnas_reset_driver);