1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) 2011, NVIDIA Corporation.
4 */
5
6#include <linux/init.h>
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/mod_devicetable.h>
10#include <linux/rfkill.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/clk.h>
14#include <linux/slab.h>
15#include <linux/acpi.h>
16#include <linux/gpio/consumer.h>
17
18struct rfkill_gpio_data {
19	const char		*name;
20	enum rfkill_type	type;
21	struct gpio_desc	*reset_gpio;
22	struct gpio_desc	*shutdown_gpio;
23
24	struct rfkill		*rfkill_dev;
25	struct clk		*clk;
26
27	bool			clk_enabled;
28};
29
30static int rfkill_gpio_set_power(void *data, bool blocked)
31{
32	struct rfkill_gpio_data *rfkill = data;
33
34	if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
35		clk_enable(rfkill->clk);
36
37	gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
38	gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
39
40	if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
41		clk_disable(rfkill->clk);
42
43	rfkill->clk_enabled = !blocked;
44
45	return 0;
46}
47
48static const struct rfkill_ops rfkill_gpio_ops = {
49	.set_block = rfkill_gpio_set_power,
50};
51
52static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
53static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
54
55static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
56	{ "reset-gpios", &reset_gpios, 1 },
57	{ "shutdown-gpios", &shutdown_gpios, 1 },
58	{ },
59};
60
61static int rfkill_gpio_acpi_probe(struct device *dev,
62				  struct rfkill_gpio_data *rfkill)
63{
64	const struct acpi_device_id *id;
65
66	id = acpi_match_device(dev->driver->acpi_match_table, dev);
67	if (!id)
68		return -ENODEV;
69
70	rfkill->type = (unsigned)id->driver_data;
71
72	return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);
73}
74
75static int rfkill_gpio_probe(struct platform_device *pdev)
76{
77	struct rfkill_gpio_data *rfkill;
78	struct gpio_desc *gpio;
79	const char *name_property;
80	const char *type_property;
81	const char *type_name;
82	int ret;
83
84	rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
85	if (!rfkill)
86		return -ENOMEM;
87
88	if (dev_of_node(&pdev->dev)) {
89		name_property = "label";
90		type_property = "radio-type";
91	} else {
92		name_property = "name";
93		type_property = "type";
94	}
95	device_property_read_string(&pdev->dev, name_property, &rfkill->name);
96	device_property_read_string(&pdev->dev, type_property, &type_name);
97
98	if (!rfkill->name)
99		rfkill->name = dev_name(&pdev->dev);
100
101	rfkill->type = rfkill_find_type(type_name);
102
103	if (ACPI_HANDLE(&pdev->dev)) {
104		ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
105		if (ret)
106			return ret;
107	}
108
109	rfkill->clk = devm_clk_get(&pdev->dev, NULL);
110
111	gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS);
112	if (IS_ERR(gpio))
113		return PTR_ERR(gpio);
114
115	rfkill->reset_gpio = gpio;
116
117	gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_ASIS);
118	if (IS_ERR(gpio))
119		return PTR_ERR(gpio);
120
121	rfkill->shutdown_gpio = gpio;
122
123	/* Make sure at-least one GPIO is defined for this instance */
124	if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
125		dev_err(&pdev->dev, "invalid platform data\n");
126		return -EINVAL;
127	}
128
129	ret = gpiod_direction_output(rfkill->reset_gpio, true);
130	if (ret)
131		return ret;
132
133	ret = gpiod_direction_output(rfkill->shutdown_gpio, true);
134	if (ret)
135		return ret;
136
137	rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
138					  rfkill->type, &rfkill_gpio_ops,
139					  rfkill);
140	if (!rfkill->rfkill_dev)
141		return -ENOMEM;
142
143	ret = rfkill_register(rfkill->rfkill_dev);
144	if (ret < 0)
145		goto err_destroy;
146
147	platform_set_drvdata(pdev, rfkill);
148
149	dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
150
151	return 0;
152
153err_destroy:
154	rfkill_destroy(rfkill->rfkill_dev);
155
156	return ret;
157}
158
159static int rfkill_gpio_remove(struct platform_device *pdev)
160{
161	struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
162
163	rfkill_unregister(rfkill->rfkill_dev);
164	rfkill_destroy(rfkill->rfkill_dev);
165
166	return 0;
167}
168
169#ifdef CONFIG_ACPI
170static const struct acpi_device_id rfkill_acpi_match[] = {
171	{ "BCM4752", RFKILL_TYPE_GPS },
172	{ "LNV4752", RFKILL_TYPE_GPS },
173	{ },
174};
175MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
176#endif
177
178static const struct of_device_id rfkill_of_match[] __maybe_unused = {
179	{ .compatible = "rfkill-gpio", },
180	{ },
181};
182MODULE_DEVICE_TABLE(of, rfkill_of_match);
183
184static struct platform_driver rfkill_gpio_driver = {
185	.probe = rfkill_gpio_probe,
186	.remove = rfkill_gpio_remove,
187	.driver = {
188		.name = "rfkill_gpio",
189		.acpi_match_table = ACPI_PTR(rfkill_acpi_match),
190		.of_match_table = of_match_ptr(rfkill_of_match),
191	},
192};
193
194module_platform_driver(rfkill_gpio_driver);
195
196MODULE_DESCRIPTION("gpio rfkill");
197MODULE_AUTHOR("NVIDIA");
198MODULE_LICENSE("GPL");
199