xref: /openbmc/linux/net/rfkill/rfkill-gpio.c (revision c819e2cf)
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/gpio.h>
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/module.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 #include <linux/rfkill-gpio.h>
31 
32 struct rfkill_gpio_data {
33 	const char		*name;
34 	enum rfkill_type	type;
35 	struct gpio_desc	*reset_gpio;
36 	struct gpio_desc	*shutdown_gpio;
37 
38 	struct rfkill		*rfkill_dev;
39 	struct clk		*clk;
40 
41 	bool			clk_enabled;
42 };
43 
44 static int rfkill_gpio_set_power(void *data, bool blocked)
45 {
46 	struct rfkill_gpio_data *rfkill = data;
47 
48 	if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
49 		clk_enable(rfkill->clk);
50 
51 	gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
52 	gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
53 
54 	if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
55 		clk_disable(rfkill->clk);
56 
57 	rfkill->clk_enabled = !blocked;
58 
59 	return 0;
60 }
61 
62 static const struct rfkill_ops rfkill_gpio_ops = {
63 	.set_block = rfkill_gpio_set_power,
64 };
65 
66 static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
67 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
68 
69 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
70 	{ "reset-gpios", &reset_gpios, 1 },
71 	{ "shutdown-gpios", &shutdown_gpios, 1 },
72 	{ },
73 };
74 
75 static int rfkill_gpio_acpi_probe(struct device *dev,
76 				  struct rfkill_gpio_data *rfkill)
77 {
78 	const struct acpi_device_id *id;
79 
80 	id = acpi_match_device(dev->driver->acpi_match_table, dev);
81 	if (!id)
82 		return -ENODEV;
83 
84 	rfkill->name = dev_name(dev);
85 	rfkill->type = (unsigned)id->driver_data;
86 
87 	return acpi_dev_add_driver_gpios(ACPI_COMPANION(dev),
88 					 acpi_rfkill_default_gpios);
89 }
90 
91 static int rfkill_gpio_probe(struct platform_device *pdev)
92 {
93 	struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
94 	struct rfkill_gpio_data *rfkill;
95 	struct gpio_desc *gpio;
96 	int ret;
97 
98 	rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
99 	if (!rfkill)
100 		return -ENOMEM;
101 
102 	if (ACPI_HANDLE(&pdev->dev)) {
103 		ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
104 		if (ret)
105 			return ret;
106 	} else if (pdata) {
107 		rfkill->name = pdata->name;
108 		rfkill->type = pdata->type;
109 	} else {
110 		return -ENODEV;
111 	}
112 
113 	rfkill->clk = devm_clk_get(&pdev->dev, NULL);
114 
115 	gpio = devm_gpiod_get(&pdev->dev, "reset");
116 	if (!IS_ERR(gpio)) {
117 		ret = gpiod_direction_output(gpio, 0);
118 		if (ret)
119 			return ret;
120 		rfkill->reset_gpio = gpio;
121 	}
122 
123 	gpio = devm_gpiod_get(&pdev->dev, "shutdown");
124 	if (!IS_ERR(gpio)) {
125 		ret = gpiod_direction_output(gpio, 0);
126 		if (ret)
127 			return ret;
128 		rfkill->shutdown_gpio = gpio;
129 	}
130 
131 	/* Make sure at-least one of the GPIO is defined and that
132 	 * a name is specified for this instance
133 	 */
134 	if ((!rfkill->reset_gpio && !rfkill->shutdown_gpio) || !rfkill->name) {
135 		dev_err(&pdev->dev, "invalid platform data\n");
136 		return -EINVAL;
137 	}
138 
139 	rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
140 					  rfkill->type, &rfkill_gpio_ops,
141 					  rfkill);
142 	if (!rfkill->rfkill_dev)
143 		return -ENOMEM;
144 
145 	ret = rfkill_register(rfkill->rfkill_dev);
146 	if (ret < 0)
147 		return ret;
148 
149 	platform_set_drvdata(pdev, rfkill);
150 
151 	dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
152 
153 	return 0;
154 }
155 
156 static int rfkill_gpio_remove(struct platform_device *pdev)
157 {
158 	struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
159 
160 	rfkill_unregister(rfkill->rfkill_dev);
161 	rfkill_destroy(rfkill->rfkill_dev);
162 
163 	acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->dev));
164 
165 	return 0;
166 }
167 
168 #ifdef CONFIG_ACPI
169 static const struct acpi_device_id rfkill_acpi_match[] = {
170 	{ "BCM2E1A", RFKILL_TYPE_BLUETOOTH },
171 	{ "BCM2E39", RFKILL_TYPE_BLUETOOTH },
172 	{ "BCM2E3D", RFKILL_TYPE_BLUETOOTH },
173 	{ "BCM2E64", RFKILL_TYPE_BLUETOOTH },
174 	{ "BCM4752", RFKILL_TYPE_GPS },
175 	{ "LNV4752", RFKILL_TYPE_GPS },
176 	{ },
177 };
178 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
179 #endif
180 
181 static struct platform_driver rfkill_gpio_driver = {
182 	.probe = rfkill_gpio_probe,
183 	.remove = rfkill_gpio_remove,
184 	.driver = {
185 		.name = "rfkill_gpio",
186 		.acpi_match_table = ACPI_PTR(rfkill_acpi_match),
187 	},
188 };
189 
190 module_platform_driver(rfkill_gpio_driver);
191 
192 MODULE_DESCRIPTION("gpio rfkill");
193 MODULE_AUTHOR("NVIDIA");
194 MODULE_LICENSE("GPL");
195