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
32struct 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
44static 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
62static const struct rfkill_ops rfkill_gpio_ops = {
63	.set_block = rfkill_gpio_set_power,
64};
65
66static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
67static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
68
69static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
70	{ "reset-gpios", &reset_gpios, 1 },
71	{ "shutdown-gpios", &shutdown_gpios, 1 },
72	{ },
73};
74
75static 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
91static 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
156static 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
169static const struct acpi_device_id rfkill_acpi_match[] = {
170	{ "BCM2E1A", RFKILL_TYPE_BLUETOOTH },
171	{ "BCM2E39", RFKILL_TYPE_BLUETOOTH },
172	{ "BCM2E3D", RFKILL_TYPE_BLUETOOTH },
173	{ "BCM2E40", RFKILL_TYPE_BLUETOOTH },
174	{ "BCM2E64", RFKILL_TYPE_BLUETOOTH },
175	{ "BCM4752", RFKILL_TYPE_GPS },
176	{ "LNV4752", RFKILL_TYPE_GPS },
177	{ },
178};
179MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
180#endif
181
182static struct platform_driver rfkill_gpio_driver = {
183	.probe = rfkill_gpio_probe,
184	.remove = rfkill_gpio_remove,
185	.driver = {
186		.name = "rfkill_gpio",
187		.acpi_match_table = ACPI_PTR(rfkill_acpi_match),
188	},
189};
190
191module_platform_driver(rfkill_gpio_driver);
192
193MODULE_DESCRIPTION("gpio rfkill");
194MODULE_AUTHOR("NVIDIA");
195MODULE_LICENSE("GPL");
196