1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Delta TN48M CPLD reset driver
4 *
5 * Copyright (C) 2021 Sartura Ltd.
6 *
7 * Author: Robert Marko <robert.marko@sartura.hr>
8 */
9
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/regmap.h>
15 #include <linux/reset-controller.h>
16
17 #include <dt-bindings/reset/delta,tn48m-reset.h>
18
19 #define TN48M_RESET_REG 0x10
20
21 #define TN48M_RESET_TIMEOUT_US 125000
22 #define TN48M_RESET_SLEEP_US 10
23
24 struct tn48_reset_map {
25 u8 bit;
26 };
27
28 struct tn48_reset_data {
29 struct reset_controller_dev rcdev;
30 struct regmap *regmap;
31 };
32
33 static const struct tn48_reset_map tn48m_resets[] = {
34 [CPU_88F7040_RESET] = {0},
35 [CPU_88F6820_RESET] = {1},
36 [MAC_98DX3265_RESET] = {2},
37 [PHY_88E1680_RESET] = {4},
38 [PHY_88E1512_RESET] = {6},
39 [POE_RESET] = {7},
40 };
41
to_tn48_reset_data(struct reset_controller_dev * rcdev)42 static inline struct tn48_reset_data *to_tn48_reset_data(
43 struct reset_controller_dev *rcdev)
44 {
45 return container_of(rcdev, struct tn48_reset_data, rcdev);
46 }
47
tn48m_control_reset(struct reset_controller_dev * rcdev,unsigned long id)48 static int tn48m_control_reset(struct reset_controller_dev *rcdev,
49 unsigned long id)
50 {
51 struct tn48_reset_data *data = to_tn48_reset_data(rcdev);
52 unsigned int val;
53
54 regmap_update_bits(data->regmap, TN48M_RESET_REG,
55 BIT(tn48m_resets[id].bit), 0);
56
57 return regmap_read_poll_timeout(data->regmap,
58 TN48M_RESET_REG,
59 val,
60 val & BIT(tn48m_resets[id].bit),
61 TN48M_RESET_SLEEP_US,
62 TN48M_RESET_TIMEOUT_US);
63 }
64
tn48m_control_status(struct reset_controller_dev * rcdev,unsigned long id)65 static int tn48m_control_status(struct reset_controller_dev *rcdev,
66 unsigned long id)
67 {
68 struct tn48_reset_data *data = to_tn48_reset_data(rcdev);
69 unsigned int regval;
70 int ret;
71
72 ret = regmap_read(data->regmap, TN48M_RESET_REG, ®val);
73 if (ret < 0)
74 return ret;
75
76 if (BIT(tn48m_resets[id].bit) & regval)
77 return 0;
78 else
79 return 1;
80 }
81
82 static const struct reset_control_ops tn48_reset_ops = {
83 .reset = tn48m_control_reset,
84 .status = tn48m_control_status,
85 };
86
tn48m_reset_probe(struct platform_device * pdev)87 static int tn48m_reset_probe(struct platform_device *pdev)
88 {
89 struct tn48_reset_data *data;
90 struct regmap *regmap;
91
92 regmap = dev_get_regmap(pdev->dev.parent, NULL);
93 if (!regmap)
94 return -ENODEV;
95
96 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
97 if (!data)
98 return -ENOMEM;
99
100 data->regmap = regmap;
101
102 data->rcdev.owner = THIS_MODULE;
103 data->rcdev.ops = &tn48_reset_ops;
104 data->rcdev.nr_resets = ARRAY_SIZE(tn48m_resets);
105 data->rcdev.of_node = pdev->dev.of_node;
106
107 return devm_reset_controller_register(&pdev->dev, &data->rcdev);
108 }
109
110 static const struct of_device_id tn48m_reset_of_match[] = {
111 { .compatible = "delta,tn48m-reset" },
112 { }
113 };
114 MODULE_DEVICE_TABLE(of, tn48m_reset_of_match);
115
116 static struct platform_driver tn48m_reset_driver = {
117 .driver = {
118 .name = "delta-tn48m-reset",
119 .of_match_table = tn48m_reset_of_match,
120 },
121 .probe = tn48m_reset_probe,
122 };
123 module_platform_driver(tn48m_reset_driver);
124
125 MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
126 MODULE_DESCRIPTION("Delta TN48M CPLD reset driver");
127 MODULE_LICENSE("GPL");
128