rfkill-gpio.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (c) 2011, NVIDIA Corporation.
  4 */
  5
  6#include <linux/dmi.h>
  7#include <linux/init.h>
  8#include <linux/kernel.h>
  9#include <linux/module.h>
 10#include <linux/mod_devicetable.h>
 11#include <linux/rfkill.h>
 12#include <linux/of.h>
 13#include <linux/platform_device.h>
 14#include <linux/clk.h>
 15#include <linux/slab.h>
 16#include <linux/acpi.h>
 17#include <linux/gpio/consumer.h>
 18
 19struct rfkill_gpio_data {
 20	const char		*name;
 21	enum rfkill_type	type;
 22	struct gpio_desc	*reset_gpio;
 23	struct gpio_desc	*shutdown_gpio;
 24
 25	struct rfkill		*rfkill_dev;
 26	struct clk		*clk;
 27
 28	bool			clk_enabled;
 29};
 30
 31static int rfkill_gpio_set_power(void *data, bool blocked)
 32{
 33	struct rfkill_gpio_data *rfkill = data;
 34
 35	if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled) {
 36		int ret = clk_enable(rfkill->clk);
 37
 38		if (ret)
 39			return ret;
 40	}
 41
 42	gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
 43	gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
 44
 45	if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
 46		clk_disable(rfkill->clk);
 47
 48	rfkill->clk_enabled = !blocked;
 49
 50	return 0;
 51}
 52
 53static const struct rfkill_ops rfkill_gpio_ops = {
 54	.set_block = rfkill_gpio_set_power,
 55};
 56
 57static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
 58static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
 59
 60static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
 61	{ "reset-gpios", &reset_gpios, 1 },
 62	{ "shutdown-gpios", &shutdown_gpios, 1 },
 63	{ },
 64};
 65
 66static int rfkill_gpio_acpi_probe(struct device *dev,
 67				  struct rfkill_gpio_data *rfkill)
 68{
 69	const struct acpi_device_id *id;
 70
 71	id = acpi_match_device(dev->driver->acpi_match_table, dev);
 72	if (!id)
 73		return -ENODEV;
 74
 75	rfkill->type = (unsigned)id->driver_data;
 76
 77	return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);
 78}
 79
 80/* List of DMI matches for devices on which rfkill-gpio should not load,
 81 * to avoid firmware bugs.
 82 */
 83static const struct dmi_system_id rfkill_gpio_deny_table[] = {
 84	{
 85		/* Lenovo Yoga Tab 3 Pro YT3-X90, bogus "BCM4752" device in DSDT */
 86		.matches = {
 87			DMI_MATCH(DMI_SYS_VENDOR, "Intel Corporation"),
 88			DMI_MATCH(DMI_PRODUCT_VERSION, "Blade3-10A-001"),
 89		},
 90	},
 91	{ }
 92};
 93
 94static int rfkill_gpio_probe(struct platform_device *pdev)
 95{
 96	struct rfkill_gpio_data *rfkill;
 97	const char *type_name = NULL;
 98	const char *name_property;
 99	const char *type_property;
100	struct gpio_desc *gpio;
101	int ret;
102
103	if (dmi_check_system(rfkill_gpio_deny_table))
104		return -ENODEV;
105
106	rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
107	if (!rfkill)
108		return -ENOMEM;
109
110	if (dev_of_node(&pdev->dev)) {
111		name_property = "label";
112		type_property = "radio-type";
113	} else {
114		name_property = "name";
115		type_property = "type";
116	}
117	device_property_read_string(&pdev->dev, name_property, &rfkill->name);
118	device_property_read_string(&pdev->dev, type_property, &type_name);
119
120	if (!rfkill->name)
121		rfkill->name = dev_name(&pdev->dev);
122
123	rfkill->type = rfkill_find_type(type_name);
124
125	if (ACPI_HANDLE(&pdev->dev)) {
126		ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
127		if (ret)
128			return ret;
129	}
130
131	rfkill->clk = devm_clk_get(&pdev->dev, NULL);
132
133	gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS);
134	if (IS_ERR(gpio))
135		return PTR_ERR(gpio);
136
137	rfkill->reset_gpio = gpio;
138
139	gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_ASIS);
140	if (IS_ERR(gpio))
141		return PTR_ERR(gpio);
142
143	rfkill->shutdown_gpio = gpio;
144
145	/* Make sure at-least one GPIO is defined for this instance */
146	if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
147		dev_err(&pdev->dev, "invalid platform data\n");
148		return -EINVAL;
149	}
150
151	ret = gpiod_direction_output(rfkill->reset_gpio, true);
152	if (ret)
153		return ret;
154
155	ret = gpiod_direction_output(rfkill->shutdown_gpio, true);
156	if (ret)
157		return ret;
158
159	rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
160					  rfkill->type, &rfkill_gpio_ops,
161					  rfkill);
162	if (!rfkill->rfkill_dev)
163		return -ENOMEM;
164
165	if (device_property_present(&pdev->dev, "default-blocked"))
166		rfkill_init_sw_state(rfkill->rfkill_dev, true);
167
168	ret = rfkill_register(rfkill->rfkill_dev);
169	if (ret < 0)
170		goto err_destroy;
171
172	platform_set_drvdata(pdev, rfkill);
173
174	dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
175
176	return 0;
177
178err_destroy:
179	rfkill_destroy(rfkill->rfkill_dev);
180
181	return ret;
182}
183
184static void rfkill_gpio_remove(struct platform_device *pdev)
185{
186	struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
187
188	rfkill_unregister(rfkill->rfkill_dev);
189	rfkill_destroy(rfkill->rfkill_dev);
190}
191
192#ifdef CONFIG_ACPI
193static const struct acpi_device_id rfkill_acpi_match[] = {
194	{ "BCM4752", RFKILL_TYPE_GPS },
195	{ "LNV4752", RFKILL_TYPE_GPS },
196	{ },
197};
198MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
199#endif
200
201static const struct of_device_id rfkill_of_match[] __maybe_unused = {
202	{ .compatible = "rfkill-gpio", },
203	{ },
204};
205MODULE_DEVICE_TABLE(of, rfkill_of_match);
206
207static struct platform_driver rfkill_gpio_driver = {
208	.probe = rfkill_gpio_probe,
209	.remove = rfkill_gpio_remove,
210	.driver = {
211		.name = "rfkill_gpio",
212		.acpi_match_table = ACPI_PTR(rfkill_acpi_match),
213		.of_match_table = of_match_ptr(rfkill_of_match),
214	},
215};
216
217module_platform_driver(rfkill_gpio_driver);
218
219MODULE_DESCRIPTION("gpio rfkill");
220MODULE_AUTHOR("NVIDIA");
221MODULE_LICENSE("GPL");