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(ptr: rfkill->clk) && !rfkill->clk_enabled)
35 clk_enable(clk: rfkill->clk);
36
37 gpiod_set_value_cansleep(desc: rfkill->shutdown_gpio, value: !blocked);
38 gpiod_set_value_cansleep(desc: rfkill->reset_gpio, value: !blocked);
39
40 if (blocked && !IS_ERR(ptr: rfkill->clk) && rfkill->clk_enabled)
41 clk_disable(clk: 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(ids: 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, gpios: 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(dev: &pdev->dev, size: sizeof(*rfkill), GFP_KERNEL);
85 if (!rfkill)
86 return -ENOMEM;
87
88 if (dev_of_node(dev: &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(dev: &pdev->dev, propname: name_property, val: &rfkill->name);
96 device_property_read_string(dev: &pdev->dev, propname: type_property, val: &type_name);
97
98 if (!rfkill->name)
99 rfkill->name = dev_name(dev: &pdev->dev);
100
101 rfkill->type = rfkill_find_type(name: type_name);
102
103 if (ACPI_HANDLE(&pdev->dev)) {
104 ret = rfkill_gpio_acpi_probe(dev: &pdev->dev, rfkill);
105 if (ret)
106 return ret;
107 }
108
109 rfkill->clk = devm_clk_get(dev: &pdev->dev, NULL);
110
111 gpio = devm_gpiod_get_optional(dev: &pdev->dev, con_id: "reset", flags: GPIOD_ASIS);
112 if (IS_ERR(ptr: gpio))
113 return PTR_ERR(ptr: gpio);
114
115 rfkill->reset_gpio = gpio;
116
117 gpio = devm_gpiod_get_optional(dev: &pdev->dev, con_id: "shutdown", flags: GPIOD_ASIS);
118 if (IS_ERR(ptr: gpio))
119 return PTR_ERR(ptr: 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 rfkill->rfkill_dev = rfkill_alloc(name: rfkill->name, parent: &pdev->dev,
130 type: rfkill->type, ops: &rfkill_gpio_ops,
131 ops_data: rfkill);
132 if (!rfkill->rfkill_dev)
133 return -ENOMEM;
134
135 ret = rfkill_register(rfkill: rfkill->rfkill_dev);
136 if (ret < 0)
137 goto err_destroy;
138
139 platform_set_drvdata(pdev, data: rfkill);
140
141 dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
142
143 return 0;
144
145err_destroy:
146 rfkill_destroy(rfkill: rfkill->rfkill_dev);
147
148 return ret;
149}
150
151static int rfkill_gpio_remove(struct platform_device *pdev)
152{
153 struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
154
155 rfkill_unregister(rfkill: rfkill->rfkill_dev);
156 rfkill_destroy(rfkill: rfkill->rfkill_dev);
157
158 return 0;
159}
160
161#ifdef CONFIG_ACPI
162static const struct acpi_device_id rfkill_acpi_match[] = {
163 { "BCM4752", RFKILL_TYPE_GPS },
164 { "LNV4752", RFKILL_TYPE_GPS },
165 { },
166};
167MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
168#endif
169
170static const struct of_device_id rfkill_of_match[] __maybe_unused = {
171 { .compatible = "rfkill-gpio", },
172 { },
173};
174MODULE_DEVICE_TABLE(of, rfkill_of_match);
175
176static struct platform_driver rfkill_gpio_driver = {
177 .probe = rfkill_gpio_probe,
178 .remove = rfkill_gpio_remove,
179 .driver = {
180 .name = "rfkill_gpio",
181 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
182 .of_match_table = of_match_ptr(rfkill_of_match),
183 },
184};
185
186module_platform_driver(rfkill_gpio_driver);
187
188MODULE_DESCRIPTION("gpio rfkill");
189MODULE_AUTHOR("NVIDIA");
190MODULE_LICENSE("GPL");
191

source code of linux/net/rfkill/rfkill-gpio.c