xref: /openbmc/linux/net/rfkill/rfkill-gpio.c (revision d2821864)
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 
rfkill_gpio_set_power(void * data,bool blocked)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 
rfkill_gpio_acpi_probe(struct device * dev,struct rfkill_gpio_data * rfkill)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 
rfkill_gpio_probe(struct platform_device * pdev)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 
rfkill_gpio_remove(struct platform_device * pdev)159 static 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
170 static const struct acpi_device_id rfkill_acpi_match[] = {
171 	{ "BCM4752", RFKILL_TYPE_GPS },
172 	{ "LNV4752", RFKILL_TYPE_GPS },
173 	{ },
174 };
175 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
176 #endif
177 
178 static const struct of_device_id rfkill_of_match[] __maybe_unused = {
179 	{ .compatible = "rfkill-gpio", },
180 	{ },
181 };
182 MODULE_DEVICE_TABLE(of, rfkill_of_match);
183 
184 static 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 
194 module_platform_driver(rfkill_gpio_driver);
195 
196 MODULE_DESCRIPTION("gpio rfkill");
197 MODULE_AUTHOR("NVIDIA");
198 MODULE_LICENSE("GPL");
199