Linux Audio

Check our new training course

In-person Linux kernel drivers training

Jun 16-20, 2025
Register
Loading...
v6.8
  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
 18struct 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
 30static 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
 48static const struct rfkill_ops rfkill_gpio_ops = {
 49	.set_block = rfkill_gpio_set_power,
 50};
 51
 52static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
 53static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
 54
 55static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
 56	{ "reset-gpios", &reset_gpios, 1 },
 57	{ "shutdown-gpios", &shutdown_gpios, 1 },
 58	{ },
 59};
 60
 61static 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
 75static 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
153err_destroy:
154	rfkill_destroy(rfkill->rfkill_dev);
155
156	return ret;
157}
158
159static 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
170static const struct acpi_device_id rfkill_acpi_match[] = {
171	{ "BCM4752", RFKILL_TYPE_GPS },
172	{ "LNV4752", RFKILL_TYPE_GPS },
173	{ },
174};
175MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
176#endif
177
178static const struct of_device_id rfkill_of_match[] __maybe_unused = {
179	{ .compatible = "rfkill-gpio", },
180	{ },
181};
182MODULE_DEVICE_TABLE(of, rfkill_of_match);
183
184static 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
194module_platform_driver(rfkill_gpio_driver);
195
196MODULE_DESCRIPTION("gpio rfkill");
197MODULE_AUTHOR("NVIDIA");
198MODULE_LICENSE("GPL");
v4.6
 
  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
 30struct 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
 42static 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
 60static const struct rfkill_ops rfkill_gpio_ops = {
 61	.set_block = rfkill_gpio_set_power,
 62};
 63
 64static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
 65static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
 66
 67static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
 68	{ "reset-gpios", &reset_gpios, 1 },
 69	{ "shutdown-gpios", &shutdown_gpios, 1 },
 70	{ },
 71};
 72
 73static 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 acpi_dev_add_driver_gpios(ACPI_COMPANION(dev),
 85					 acpi_rfkill_default_gpios);
 86}
 87
 88static int rfkill_gpio_probe(struct platform_device *pdev)
 89{
 90	struct rfkill_gpio_data *rfkill;
 91	struct gpio_desc *gpio;
 
 
 92	const char *type_name;
 93	int ret;
 94
 95	rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
 96	if (!rfkill)
 97		return -ENOMEM;
 98
 99	device_property_read_string(&pdev->dev, "name", &rfkill->name);
100	device_property_read_string(&pdev->dev, "type", &type_name);
 
 
 
 
 
 
 
101
102	if (!rfkill->name)
103		rfkill->name = dev_name(&pdev->dev);
104
105	rfkill->type = rfkill_find_type(type_name);
106
107	if (ACPI_HANDLE(&pdev->dev)) {
108		ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
109		if (ret)
110			return ret;
111	}
112
113	rfkill->clk = devm_clk_get(&pdev->dev, NULL);
114
115	gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
116	if (IS_ERR(gpio))
117		return PTR_ERR(gpio);
118
119	rfkill->reset_gpio = gpio;
120
121	gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_OUT_LOW);
122	if (IS_ERR(gpio))
123		return PTR_ERR(gpio);
124
125	rfkill->shutdown_gpio = gpio;
126
127	/* Make sure at-least one GPIO is defined for this instance */
128	if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
129		dev_err(&pdev->dev, "invalid platform data\n");
130		return -EINVAL;
131	}
132
 
 
 
 
 
 
 
 
133	rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
134					  rfkill->type, &rfkill_gpio_ops,
135					  rfkill);
136	if (!rfkill->rfkill_dev)
137		return -ENOMEM;
138
139	ret = rfkill_register(rfkill->rfkill_dev);
140	if (ret < 0)
141		return ret;
142
143	platform_set_drvdata(pdev, rfkill);
144
145	dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
146
147	return 0;
 
 
 
 
 
148}
149
150static int rfkill_gpio_remove(struct platform_device *pdev)
151{
152	struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
153
154	rfkill_unregister(rfkill->rfkill_dev);
155	rfkill_destroy(rfkill->rfkill_dev);
156
157	acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->dev));
158
159	return 0;
160}
161
162#ifdef CONFIG_ACPI
163static const struct acpi_device_id rfkill_acpi_match[] = {
164	{ "BCM4752", RFKILL_TYPE_GPS },
165	{ "LNV4752", RFKILL_TYPE_GPS },
166	{ },
167};
168MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
169#endif
170
 
 
 
 
 
 
171static struct platform_driver rfkill_gpio_driver = {
172	.probe = rfkill_gpio_probe,
173	.remove = rfkill_gpio_remove,
174	.driver = {
175		.name = "rfkill_gpio",
176		.acpi_match_table = ACPI_PTR(rfkill_acpi_match),
 
177	},
178};
179
180module_platform_driver(rfkill_gpio_driver);
181
182MODULE_DESCRIPTION("gpio rfkill");
183MODULE_AUTHOR("NVIDIA");
184MODULE_LICENSE("GPL");