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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (c) 2016-2017 Linaro Ltd.4 * Copyright (c) 2016-2017 HiSilicon Technologies Co., Ltd.5 */6#include <linux/kernel.h>7#include <linux/mfd/syscon.h>8#include <linux/module.h>9#include <linux/of.h>10#include <linux/platform_device.h>11#include <linux/regmap.h>12#include <linux/reset-controller.h>13 14struct hi3660_reset_controller {15 struct reset_controller_dev rst;16 struct regmap *map;17};18 19#define to_hi3660_reset_controller(_rst) \20 container_of(_rst, struct hi3660_reset_controller, rst)21 22static int hi3660_reset_program_hw(struct reset_controller_dev *rcdev,23 unsigned long idx, bool assert)24{25 struct hi3660_reset_controller *rc = to_hi3660_reset_controller(rcdev);26 unsigned int offset = idx >> 8;27 unsigned int mask = BIT(idx & 0x1f);28 29 if (assert)30 return regmap_write(rc->map, offset, mask);31 else32 return regmap_write(rc->map, offset + 4, mask);33}34 35static int hi3660_reset_assert(struct reset_controller_dev *rcdev,36 unsigned long idx)37{38 return hi3660_reset_program_hw(rcdev, idx, true);39}40 41static int hi3660_reset_deassert(struct reset_controller_dev *rcdev,42 unsigned long idx)43{44 return hi3660_reset_program_hw(rcdev, idx, false);45}46 47static int hi3660_reset_dev(struct reset_controller_dev *rcdev,48 unsigned long idx)49{50 int err;51 52 err = hi3660_reset_assert(rcdev, idx);53 if (err)54 return err;55 56 return hi3660_reset_deassert(rcdev, idx);57}58 59static const struct reset_control_ops hi3660_reset_ops = {60 .reset = hi3660_reset_dev,61 .assert = hi3660_reset_assert,62 .deassert = hi3660_reset_deassert,63};64 65static int hi3660_reset_xlate(struct reset_controller_dev *rcdev,66 const struct of_phandle_args *reset_spec)67{68 unsigned int offset, bit;69 70 offset = reset_spec->args[0];71 bit = reset_spec->args[1];72 73 return (offset << 8) | bit;74}75 76static int hi3660_reset_probe(struct platform_device *pdev)77{78 struct hi3660_reset_controller *rc;79 struct device_node *np = pdev->dev.of_node;80 struct device *dev = &pdev->dev;81 82 rc = devm_kzalloc(dev, sizeof(*rc), GFP_KERNEL);83 if (!rc)84 return -ENOMEM;85 86 rc->map = syscon_regmap_lookup_by_phandle(np, "hisilicon,rst-syscon");87 if (rc->map == ERR_PTR(-ENODEV)) {88 /* fall back to the deprecated compatible */89 rc->map = syscon_regmap_lookup_by_phandle(np,90 "hisi,rst-syscon");91 }92 if (IS_ERR(rc->map)) {93 return dev_err_probe(dev, PTR_ERR(rc->map),94 "failed to get hisilicon,rst-syscon\n");95 }96 97 rc->rst.ops = &hi3660_reset_ops,98 rc->rst.of_node = np;99 rc->rst.of_reset_n_cells = 2;100 rc->rst.of_xlate = hi3660_reset_xlate;101 102 return reset_controller_register(&rc->rst);103}104 105static const struct of_device_id hi3660_reset_match[] = {106 { .compatible = "hisilicon,hi3660-reset", },107 {},108};109MODULE_DEVICE_TABLE(of, hi3660_reset_match);110 111static struct platform_driver hi3660_reset_driver = {112 .probe = hi3660_reset_probe,113 .driver = {114 .name = "hi3660-reset",115 .of_match_table = hi3660_reset_match,116 },117};118 119static int __init hi3660_reset_init(void)120{121 return platform_driver_register(&hi3660_reset_driver);122}123arch_initcall(hi3660_reset_init);124 125MODULE_LICENSE("GPL");126MODULE_ALIAS("platform:hi3660-reset");127MODULE_DESCRIPTION("HiSilicon Hi3660 Reset Driver");128