xref: /openbmc/linux/net/rfkill/rfkill-gpio.c (revision d0e22329)
1 /*
2  * Copyright (c) 2011, NVIDIA Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along
15  * with this program; if not, write to the Free Software Foundation, Inc.,
16  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
17  */
18 
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/mod_devicetable.h>
23 #include <linux/rfkill.h>
24 #include <linux/platform_device.h>
25 #include <linux/clk.h>
26 #include <linux/slab.h>
27 #include <linux/acpi.h>
28 #include <linux/gpio/consumer.h>
29 
30 struct rfkill_gpio_data {
31 	const char		*name;
32 	enum rfkill_type	type;
33 	struct gpio_desc	*reset_gpio;
34 	struct gpio_desc	*shutdown_gpio;
35 
36 	struct rfkill		*rfkill_dev;
37 	struct clk		*clk;
38 
39 	bool			clk_enabled;
40 };
41 
42 static int rfkill_gpio_set_power(void *data, bool blocked)
43 {
44 	struct rfkill_gpio_data *rfkill = data;
45 
46 	if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
47 		clk_enable(rfkill->clk);
48 
49 	gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
50 	gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
51 
52 	if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
53 		clk_disable(rfkill->clk);
54 
55 	rfkill->clk_enabled = !blocked;
56 
57 	return 0;
58 }
59 
60 static const struct rfkill_ops rfkill_gpio_ops = {
61 	.set_block = rfkill_gpio_set_power,
62 };
63 
64 static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
65 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
66 
67 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
68 	{ "reset-gpios", &reset_gpios, 1 },
69 	{ "shutdown-gpios", &shutdown_gpios, 1 },
70 	{ },
71 };
72 
73 static int rfkill_gpio_acpi_probe(struct device *dev,
74 				  struct rfkill_gpio_data *rfkill)
75 {
76 	const struct acpi_device_id *id;
77 
78 	id = acpi_match_device(dev->driver->acpi_match_table, dev);
79 	if (!id)
80 		return -ENODEV;
81 
82 	rfkill->type = (unsigned)id->driver_data;
83 
84 	return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);
85 }
86 
87 static int rfkill_gpio_probe(struct platform_device *pdev)
88 {
89 	struct rfkill_gpio_data *rfkill;
90 	struct gpio_desc *gpio;
91 	const char *type_name;
92 	int ret;
93 
94 	rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
95 	if (!rfkill)
96 		return -ENOMEM;
97 
98 	device_property_read_string(&pdev->dev, "name", &rfkill->name);
99 	device_property_read_string(&pdev->dev, "type", &type_name);
100 
101 	if (!rfkill->name)
102 		rfkill->name = dev_name(&pdev->dev);
103 
104 	rfkill->type = rfkill_find_type(type_name);
105 
106 	if (ACPI_HANDLE(&pdev->dev)) {
107 		ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
108 		if (ret)
109 			return ret;
110 	}
111 
112 	rfkill->clk = devm_clk_get(&pdev->dev, NULL);
113 
114 	gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
115 	if (IS_ERR(gpio))
116 		return PTR_ERR(gpio);
117 
118 	rfkill->reset_gpio = gpio;
119 
120 	gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_OUT_LOW);
121 	if (IS_ERR(gpio))
122 		return PTR_ERR(gpio);
123 
124 	rfkill->shutdown_gpio = gpio;
125 
126 	/* Make sure at-least one GPIO is defined for this instance */
127 	if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
128 		dev_err(&pdev->dev, "invalid platform data\n");
129 		return -EINVAL;
130 	}
131 
132 	rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
133 					  rfkill->type, &rfkill_gpio_ops,
134 					  rfkill);
135 	if (!rfkill->rfkill_dev)
136 		return -ENOMEM;
137 
138 	ret = rfkill_register(rfkill->rfkill_dev);
139 	if (ret < 0)
140 		goto err_destroy;
141 
142 	platform_set_drvdata(pdev, rfkill);
143 
144 	dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
145 
146 	return 0;
147 
148 err_destroy:
149 	rfkill_destroy(rfkill->rfkill_dev);
150 
151 	return ret;
152 }
153 
154 static int rfkill_gpio_remove(struct platform_device *pdev)
155 {
156 	struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
157 
158 	rfkill_unregister(rfkill->rfkill_dev);
159 	rfkill_destroy(rfkill->rfkill_dev);
160 
161 	return 0;
162 }
163 
164 #ifdef CONFIG_ACPI
165 static const struct acpi_device_id rfkill_acpi_match[] = {
166 	{ "BCM4752", RFKILL_TYPE_GPS },
167 	{ "LNV4752", RFKILL_TYPE_GPS },
168 	{ },
169 };
170 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
171 #endif
172 
173 static struct platform_driver rfkill_gpio_driver = {
174 	.probe = rfkill_gpio_probe,
175 	.remove = rfkill_gpio_remove,
176 	.driver = {
177 		.name = "rfkill_gpio",
178 		.acpi_match_table = ACPI_PTR(rfkill_acpi_match),
179 	},
180 };
181 
182 module_platform_driver(rfkill_gpio_driver);
183 
184 MODULE_DESCRIPTION("gpio rfkill");
185 MODULE_AUTHOR("NVIDIA");
186 MODULE_LICENSE("GPL");
187