1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * TI TPS380x Supply Voltage Supervisor and Reset Controller Driver |
4 | * |
5 | * Copyright (C) 2022 Pengutronix, Marco Felsch <kernel@pengutronix.de> |
6 | * |
7 | * Based on Simple Reset Controller Driver |
8 | * |
9 | * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de> |
10 | */ |
11 | |
12 | #include <linux/delay.h> |
13 | #include <linux/gpio/consumer.h> |
14 | #include <linux/module.h> |
15 | #include <linux/of.h> |
16 | #include <linux/platform_device.h> |
17 | #include <linux/property.h> |
18 | #include <linux/reset-controller.h> |
19 | |
20 | struct tps380x_reset { |
21 | struct reset_controller_dev rcdev; |
22 | struct gpio_desc *reset_gpio; |
23 | unsigned int reset_ms; |
24 | }; |
25 | |
26 | struct tps380x_reset_devdata { |
27 | unsigned int min_reset_ms; |
28 | unsigned int typ_reset_ms; |
29 | unsigned int max_reset_ms; |
30 | }; |
31 | |
32 | static inline |
33 | struct tps380x_reset *to_tps380x_reset(struct reset_controller_dev *rcdev) |
34 | { |
35 | return container_of(rcdev, struct tps380x_reset, rcdev); |
36 | } |
37 | |
38 | static int |
39 | tps380x_reset_assert(struct reset_controller_dev *rcdev, unsigned long id) |
40 | { |
41 | struct tps380x_reset *tps380x = to_tps380x_reset(rcdev); |
42 | |
43 | gpiod_set_value_cansleep(desc: tps380x->reset_gpio, value: 1); |
44 | |
45 | return 0; |
46 | } |
47 | |
48 | static int |
49 | tps380x_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id) |
50 | { |
51 | struct tps380x_reset *tps380x = to_tps380x_reset(rcdev); |
52 | |
53 | gpiod_set_value_cansleep(desc: tps380x->reset_gpio, value: 0); |
54 | msleep(msecs: tps380x->reset_ms); |
55 | |
56 | return 0; |
57 | } |
58 | |
59 | static const struct reset_control_ops reset_tps380x_ops = { |
60 | .assert = tps380x_reset_assert, |
61 | .deassert = tps380x_reset_deassert, |
62 | }; |
63 | |
64 | static int tps380x_reset_of_xlate(struct reset_controller_dev *rcdev, |
65 | const struct of_phandle_args *reset_spec) |
66 | { |
67 | /* No special handling needed, we have only one reset line per device */ |
68 | return 0; |
69 | } |
70 | |
71 | static int tps380x_reset_probe(struct platform_device *pdev) |
72 | { |
73 | struct device *dev = &pdev->dev; |
74 | const struct tps380x_reset_devdata *devdata; |
75 | struct tps380x_reset *tps380x; |
76 | |
77 | devdata = device_get_match_data(dev); |
78 | if (!devdata) |
79 | return -EINVAL; |
80 | |
81 | tps380x = devm_kzalloc(dev, size: sizeof(*tps380x), GFP_KERNEL); |
82 | if (!tps380x) |
83 | return -ENOMEM; |
84 | |
85 | tps380x->reset_gpio = devm_gpiod_get(dev, con_id: "reset" , flags: GPIOD_OUT_HIGH); |
86 | if (IS_ERR(ptr: tps380x->reset_gpio)) |
87 | return dev_err_probe(dev, err: PTR_ERR(ptr: tps380x->reset_gpio), |
88 | fmt: "Failed to get GPIO\n" ); |
89 | |
90 | tps380x->reset_ms = devdata->max_reset_ms; |
91 | |
92 | tps380x->rcdev.ops = &reset_tps380x_ops; |
93 | tps380x->rcdev.owner = THIS_MODULE; |
94 | tps380x->rcdev.dev = dev; |
95 | tps380x->rcdev.of_node = dev->of_node; |
96 | tps380x->rcdev.of_reset_n_cells = 0; |
97 | tps380x->rcdev.of_xlate = tps380x_reset_of_xlate; |
98 | tps380x->rcdev.nr_resets = 1; |
99 | |
100 | return devm_reset_controller_register(dev, rcdev: &tps380x->rcdev); |
101 | } |
102 | |
103 | static const struct tps380x_reset_devdata tps3801_reset_data = { |
104 | .min_reset_ms = 120, |
105 | .typ_reset_ms = 200, |
106 | .max_reset_ms = 280, |
107 | }; |
108 | |
109 | static const struct of_device_id tps380x_reset_dt_ids[] = { |
110 | { .compatible = "ti,tps3801" , .data = &tps3801_reset_data }, |
111 | { /* sentinel */ }, |
112 | }; |
113 | MODULE_DEVICE_TABLE(of, tps380x_reset_dt_ids); |
114 | |
115 | static struct platform_driver tps380x_reset_driver = { |
116 | .probe = tps380x_reset_probe, |
117 | .driver = { |
118 | .name = "tps380x-reset" , |
119 | .of_match_table = tps380x_reset_dt_ids, |
120 | }, |
121 | }; |
122 | module_platform_driver(tps380x_reset_driver); |
123 | |
124 | MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>" ); |
125 | MODULE_DESCRIPTION("TI TPS380x Supply Voltage Supervisor and Reset Driver" ); |
126 | MODULE_LICENSE("GPL v2" ); |
127 | |