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
18 struct 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
30 static 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
48 static const struct rfkill_ops rfkill_gpio_ops = {
49 .set_block = rfkill_gpio_set_power,
50 };
51
52 static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
53 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
54
55 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
56 { "reset-gpios", &reset_gpios, 1 },
57 { "shutdown-gpios", &shutdown_gpios, 1 },
58 { },
59 };
60
61 static 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
75 static 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
153 err_destroy:
154 rfkill_destroy(rfkill->rfkill_dev);
155
156 return ret;
157 }
158
159 static void 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
167 #ifdef CONFIG_ACPI
168 static const struct acpi_device_id rfkill_acpi_match[] = {
169 { "BCM4752", RFKILL_TYPE_GPS },
170 { "LNV4752", RFKILL_TYPE_GPS },
171 { },
172 };
173 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
174 #endif
175
176 static const struct of_device_id rfkill_of_match[] __maybe_unused = {
177 { .compatible = "rfkill-gpio", },
178 { },
179 };
180 MODULE_DEVICE_TABLE(of, rfkill_of_match);
181
182 static struct platform_driver rfkill_gpio_driver = {
183 .probe = rfkill_gpio_probe,
184 .remove_new = rfkill_gpio_remove,
185 .driver = {
186 .name = "rfkill_gpio",
187 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
188 .of_match_table = of_match_ptr(rfkill_of_match),
189 },
190 };
191
192 module_platform_driver(rfkill_gpio_driver);
193
194 MODULE_DESCRIPTION("gpio rfkill");
195 MODULE_AUTHOR("NVIDIA");
196 MODULE_LICENSE("GPL");
197
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