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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2020 Western Digital Corporation or its affiliates.
*/
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
#include <linux/delay.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <soc/canaan/k210-sysctl.h>
#include <dt-bindings/reset/k210-rst.h>
#define K210_RST_MASK 0x27FFFFFF
struct k210_rst {
struct regmap *map;
struct reset_controller_dev rcdev;
};
static inline struct k210_rst *
to_k210_rst(struct reset_controller_dev *rcdev)
{
return container_of(rcdev, struct k210_rst, rcdev);
}
static inline int k210_rst_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct k210_rst *ksr = to_k210_rst(rcdev);
return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 1);
}
static inline int k210_rst_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct k210_rst *ksr = to_k210_rst(rcdev);
return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 0);
}
static int k210_rst_reset(struct reset_controller_dev *rcdev,
unsigned long id)
{
int ret;
ret = k210_rst_assert(rcdev, id);
if (ret == 0) {
udelay(10);
ret = k210_rst_deassert(rcdev, id);
}
return ret;
}
static int k210_rst_status(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct k210_rst *ksr = to_k210_rst(rcdev);
u32 reg, bit = BIT(id);
int ret;
ret = regmap_read(ksr->map, K210_SYSCTL_PERI_RESET, ®);
if (ret)
return ret;
return reg & bit;
}
static int k210_rst_xlate(struct reset_controller_dev *rcdev,
const struct of_phandle_args *reset_spec)
{
unsigned long id = reset_spec->args[0];
if (!(BIT(id) & K210_RST_MASK))
return -EINVAL;
return id;
}
static const struct reset_control_ops k210_rst_ops = {
.assert = k210_rst_assert,
.deassert = k210_rst_deassert,
.reset = k210_rst_reset,
.status = k210_rst_status,
};
static int k210_rst_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *parent_np;
struct k210_rst *ksr;
dev_info(dev, "K210 reset controller\n");
ksr = devm_kzalloc(dev, sizeof(*ksr), GFP_KERNEL);
if (!ksr)
return -ENOMEM;
parent_np = of_get_parent(dev->of_node);
ksr->map = syscon_node_to_regmap(parent_np);
of_node_put(parent_np);
if (IS_ERR(ksr->map))
return PTR_ERR(ksr->map);
ksr->rcdev.owner = THIS_MODULE;
ksr->rcdev.dev = dev;
ksr->rcdev.of_node = dev->of_node;
ksr->rcdev.ops = &k210_rst_ops;
ksr->rcdev.nr_resets = fls(K210_RST_MASK);
ksr->rcdev.of_reset_n_cells = 1;
ksr->rcdev.of_xlate = k210_rst_xlate;
return devm_reset_controller_register(dev, &ksr->rcdev);
}
static const struct of_device_id k210_rst_dt_ids[] = {
{ .compatible = "canaan,k210-rst" },
{ /* sentinel */ },
};
static struct platform_driver k210_rst_driver = {
.probe = k210_rst_probe,
.driver = {
.name = "k210-rst",
.of_match_table = k210_rst_dt_ids,
},
};
builtin_platform_driver(k210_rst_driver);
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