1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (c) 2016-2017 Linaro Ltd.
4 * Copyright (c) 2016-2017 HiSilicon Technologies Co., Ltd.
6 #include <linux/kernel.h>
7 #include <linux/mfd/syscon.h>
8 #include <linux/module.h>
9 #include <linux/of_device.h>
10 #include <linux/platform_device.h>
11 #include <linux/regmap.h>
12 #include <linux/reset-controller.h>
14 struct hi3660_reset_controller {
15 struct reset_controller_dev rst;
19 #define to_hi3660_reset_controller(_rst) \
20 container_of(_rst, struct hi3660_reset_controller, rst)
22 static int hi3660_reset_program_hw(struct reset_controller_dev *rcdev,
23 unsigned long idx, bool assert)
25 struct hi3660_reset_controller *rc = to_hi3660_reset_controller(rcdev);
26 unsigned int offset = idx >> 8;
27 unsigned int mask = BIT(idx & 0x1f);
30 return regmap_write(rc->map, offset, mask);
32 return regmap_write(rc->map, offset + 4, mask);
35 static int hi3660_reset_assert(struct reset_controller_dev *rcdev,
38 return hi3660_reset_program_hw(rcdev, idx, true);
41 static int hi3660_reset_deassert(struct reset_controller_dev *rcdev,
44 return hi3660_reset_program_hw(rcdev, idx, false);
47 static int hi3660_reset_dev(struct reset_controller_dev *rcdev,
52 err = hi3660_reset_assert(rcdev, idx);
56 return hi3660_reset_deassert(rcdev, idx);
59 static const struct reset_control_ops hi3660_reset_ops = {
60 .reset = hi3660_reset_dev,
61 .assert = hi3660_reset_assert,
62 .deassert = hi3660_reset_deassert,
65 static int hi3660_reset_xlate(struct reset_controller_dev *rcdev,
66 const struct of_phandle_args *reset_spec)
68 unsigned int offset, bit;
70 offset = reset_spec->args[0];
71 bit = reset_spec->args[1];
73 return (offset << 8) | bit;
76 static int hi3660_reset_probe(struct platform_device *pdev)
78 struct hi3660_reset_controller *rc;
79 struct device_node *np = pdev->dev.of_node;
80 struct device *dev = &pdev->dev;
82 rc = devm_kzalloc(dev, sizeof(*rc), GFP_KERNEL);
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,
92 if (IS_ERR(rc->map)) {
93 dev_err(dev, "failed to get hisilicon,rst-syscon\n");
94 return PTR_ERR(rc->map);
97 rc->rst.ops = &hi3660_reset_ops,
99 rc->rst.of_reset_n_cells = 2;
100 rc->rst.of_xlate = hi3660_reset_xlate;
102 return reset_controller_register(&rc->rst);
105 static const struct of_device_id hi3660_reset_match[] = {
106 { .compatible = "hisilicon,hi3660-reset", },
109 MODULE_DEVICE_TABLE(of, hi3660_reset_match);
111 static struct platform_driver hi3660_reset_driver = {
112 .probe = hi3660_reset_probe,
114 .name = "hi3660-reset",
115 .of_match_table = hi3660_reset_match,
119 static int __init hi3660_reset_init(void)
121 return platform_driver_register(&hi3660_reset_driver);
123 arch_initcall(hi3660_reset_init);
125 MODULE_LICENSE("GPL");
126 MODULE_ALIAS("platform:hi3660-reset");
127 MODULE_DESCRIPTION("HiSilicon Hi3660 Reset Driver");