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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/of_device.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 = of_get_parent(dev->of_node);
- struct k210_rst *ksr;
- dev_info(dev, "K210 reset controller\n");
- ksr = devm_kzalloc(dev, sizeof(*ksr), GFP_KERNEL);
- if (!ksr)
- return -ENOMEM;
- 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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