linux/drivers/reset/reset-tn48m.c
Robert Marko 5cd3921d16 reset: Add Delta TN48M CPLD reset controller
Delta TN48M CPLD exposes resets for the following:
* 88F7040 SoC
* 88F6820 SoC
* 98DX3265 switch MAC-s
* 88E1680 PHY-s
* 88E1512 PHY
* PoE PSE controller

Controller supports only self clearing resets.

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Link: https://lore.kernel.org/r/20220131133049.77780-5-robert.marko@sartura.hr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-25 09:59:35 +01:00

129 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Delta TN48M CPLD reset driver
*
* Copyright (C) 2021 Sartura Ltd.
*
* Author: Robert Marko <robert.marko@sartura.hr>
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset-controller.h>
#include <dt-bindings/reset/delta,tn48m-reset.h>
#define TN48M_RESET_REG 0x10
#define TN48M_RESET_TIMEOUT_US 125000
#define TN48M_RESET_SLEEP_US 10
struct tn48_reset_map {
u8 bit;
};
struct tn48_reset_data {
struct reset_controller_dev rcdev;
struct regmap *regmap;
};
static const struct tn48_reset_map tn48m_resets[] = {
[CPU_88F7040_RESET] = {0},
[CPU_88F6820_RESET] = {1},
[MAC_98DX3265_RESET] = {2},
[PHY_88E1680_RESET] = {4},
[PHY_88E1512_RESET] = {6},
[POE_RESET] = {7},
};
static inline struct tn48_reset_data *to_tn48_reset_data(
struct reset_controller_dev *rcdev)
{
return container_of(rcdev, struct tn48_reset_data, rcdev);
}
static int tn48m_control_reset(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct tn48_reset_data *data = to_tn48_reset_data(rcdev);
unsigned int val;
regmap_update_bits(data->regmap, TN48M_RESET_REG,
BIT(tn48m_resets[id].bit), 0);
return regmap_read_poll_timeout(data->regmap,
TN48M_RESET_REG,
val,
val & BIT(tn48m_resets[id].bit),
TN48M_RESET_SLEEP_US,
TN48M_RESET_TIMEOUT_US);
}
static int tn48m_control_status(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct tn48_reset_data *data = to_tn48_reset_data(rcdev);
unsigned int regval;
int ret;
ret = regmap_read(data->regmap, TN48M_RESET_REG, &regval);
if (ret < 0)
return ret;
if (BIT(tn48m_resets[id].bit) & regval)
return 0;
else
return 1;
}
static const struct reset_control_ops tn48_reset_ops = {
.reset = tn48m_control_reset,
.status = tn48m_control_status,
};
static int tn48m_reset_probe(struct platform_device *pdev)
{
struct tn48_reset_data *data;
struct regmap *regmap;
regmap = dev_get_regmap(pdev->dev.parent, NULL);
if (!regmap)
return -ENODEV;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->regmap = regmap;
data->rcdev.owner = THIS_MODULE;
data->rcdev.ops = &tn48_reset_ops;
data->rcdev.nr_resets = ARRAY_SIZE(tn48m_resets);
data->rcdev.of_node = pdev->dev.of_node;
return devm_reset_controller_register(&pdev->dev, &data->rcdev);
}
static const struct of_device_id tn48m_reset_of_match[] = {
{ .compatible = "delta,tn48m-reset" },
{ }
};
MODULE_DEVICE_TABLE(of, tn48m_reset_of_match);
static struct platform_driver tn48m_reset_driver = {
.driver = {
.name = "delta-tn48m-reset",
.of_match_table = tn48m_reset_of_match,
},
.probe = tn48m_reset_probe,
};
module_platform_driver(tn48m_reset_driver);
MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
MODULE_DESCRIPTION("Delta TN48M CPLD reset driver");
MODULE_LICENSE("GPL");