132 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (c) 2020 Western Digital Corporation or its affiliates.4 */5#include <linux/of.h>6#include <linux/platform_device.h>7#include <linux/reset-controller.h>8#include <linux/delay.h>9#include <linux/mfd/syscon.h>10#include <linux/regmap.h>11#include <soc/canaan/k210-sysctl.h>12 13#include <dt-bindings/reset/k210-rst.h>14 15#define K210_RST_MASK 0x27FFFFFF16 17struct k210_rst {18 struct regmap *map;19 struct reset_controller_dev rcdev;20};21 22static inline struct k210_rst *23to_k210_rst(struct reset_controller_dev *rcdev)24{25 return container_of(rcdev, struct k210_rst, rcdev);26}27 28static inline int k210_rst_assert(struct reset_controller_dev *rcdev,29 unsigned long id)30{31 struct k210_rst *ksr = to_k210_rst(rcdev);32 33 return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 1);34}35 36static inline int k210_rst_deassert(struct reset_controller_dev *rcdev,37 unsigned long id)38{39 struct k210_rst *ksr = to_k210_rst(rcdev);40 41 return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 0);42}43 44static int k210_rst_reset(struct reset_controller_dev *rcdev,45 unsigned long id)46{47 int ret;48 49 ret = k210_rst_assert(rcdev, id);50 if (ret == 0) {51 udelay(10);52 ret = k210_rst_deassert(rcdev, id);53 }54 55 return ret;56}57 58static int k210_rst_status(struct reset_controller_dev *rcdev,59 unsigned long id)60{61 struct k210_rst *ksr = to_k210_rst(rcdev);62 u32 reg, bit = BIT(id);63 int ret;64 65 ret = regmap_read(ksr->map, K210_SYSCTL_PERI_RESET, ®);66 if (ret)67 return ret;68 69 return reg & bit;70}71 72static int k210_rst_xlate(struct reset_controller_dev *rcdev,73 const struct of_phandle_args *reset_spec)74{75 unsigned long id = reset_spec->args[0];76 77 if (!(BIT(id) & K210_RST_MASK))78 return -EINVAL;79 80 return id;81}82 83static const struct reset_control_ops k210_rst_ops = {84 .assert = k210_rst_assert,85 .deassert = k210_rst_deassert,86 .reset = k210_rst_reset,87 .status = k210_rst_status,88};89 90static int k210_rst_probe(struct platform_device *pdev)91{92 struct device *dev = &pdev->dev;93 struct device_node *parent_np;94 struct k210_rst *ksr;95 96 dev_info(dev, "K210 reset controller\n");97 98 ksr = devm_kzalloc(dev, sizeof(*ksr), GFP_KERNEL);99 if (!ksr)100 return -ENOMEM;101 102 parent_np = of_get_parent(dev->of_node);103 ksr->map = syscon_node_to_regmap(parent_np);104 of_node_put(parent_np);105 if (IS_ERR(ksr->map))106 return PTR_ERR(ksr->map);107 108 ksr->rcdev.owner = THIS_MODULE;109 ksr->rcdev.dev = dev;110 ksr->rcdev.of_node = dev->of_node;111 ksr->rcdev.ops = &k210_rst_ops;112 ksr->rcdev.nr_resets = fls(K210_RST_MASK);113 ksr->rcdev.of_reset_n_cells = 1;114 ksr->rcdev.of_xlate = k210_rst_xlate;115 116 return devm_reset_controller_register(dev, &ksr->rcdev);117}118 119static const struct of_device_id k210_rst_dt_ids[] = {120 { .compatible = "canaan,k210-rst" },121 { /* sentinel */ },122};123 124static struct platform_driver k210_rst_driver = {125 .probe = k210_rst_probe,126 .driver = {127 .name = "k210-rst",128 .of_match_table = k210_rst_dt_ids,129 },130};131builtin_platform_driver(k210_rst_driver);132