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/platform_device.h>
12 #include <linux/clk.h>
13 #include <linux/slab.h>
14 #include <linux/acpi.h>
15 #include <linux/gpio/consumer.h>
16
17 struct rfkill_gpio_data {
18 const char *name;
19 enum rfkill_type type;
20 struct gpio_desc *reset_gpio;
21 struct gpio_desc *shutdown_gpio;
22
23 struct rfkill *rfkill_dev;
24 struct clk *clk;
25
26 bool clk_enabled;
27 };
28
rfkill_gpio_set_power(void * data,bool blocked)29 static int rfkill_gpio_set_power(void *data, bool blocked)
30 {
31 struct rfkill_gpio_data *rfkill = data;
32
33 if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
34 clk_enable(rfkill->clk);
35
36 gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
37 gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
38
39 if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
40 clk_disable(rfkill->clk);
41
42 rfkill->clk_enabled = !blocked;
43
44 return 0;
45 }
46
47 static const struct rfkill_ops rfkill_gpio_ops = {
48 .set_block = rfkill_gpio_set_power,
49 };
50
51 static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
52 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
53
54 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
55 { "reset-gpios", &reset_gpios, 1 },
56 { "shutdown-gpios", &shutdown_gpios, 1 },
57 { },
58 };
59
rfkill_gpio_acpi_probe(struct device * dev,struct rfkill_gpio_data * rfkill)60 static int rfkill_gpio_acpi_probe(struct device *dev,
61 struct rfkill_gpio_data *rfkill)
62 {
63 const struct acpi_device_id *id;
64
65 id = acpi_match_device(dev->driver->acpi_match_table, dev);
66 if (!id)
67 return -ENODEV;
68
69 rfkill->type = (unsigned)id->driver_data;
70
71 return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);
72 }
73
rfkill_gpio_probe(struct platform_device * pdev)74 static int rfkill_gpio_probe(struct platform_device *pdev)
75 {
76 struct rfkill_gpio_data *rfkill;
77 struct gpio_desc *gpio;
78 const char *type_name;
79 int ret;
80
81 rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
82 if (!rfkill)
83 return -ENOMEM;
84
85 device_property_read_string(&pdev->dev, "name", &rfkill->name);
86 device_property_read_string(&pdev->dev, "type", &type_name);
87
88 if (!rfkill->name)
89 rfkill->name = dev_name(&pdev->dev);
90
91 rfkill->type = rfkill_find_type(type_name);
92
93 if (ACPI_HANDLE(&pdev->dev)) {
94 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
95 if (ret)
96 return ret;
97 }
98
99 rfkill->clk = devm_clk_get(&pdev->dev, NULL);
100
101 gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
102 if (IS_ERR(gpio))
103 return PTR_ERR(gpio);
104
105 rfkill->reset_gpio = gpio;
106
107 gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_OUT_LOW);
108 if (IS_ERR(gpio))
109 return PTR_ERR(gpio);
110
111 rfkill->shutdown_gpio = gpio;
112
113 /* Make sure at-least one GPIO is defined for this instance */
114 if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
115 dev_err(&pdev->dev, "invalid platform data\n");
116 return -EINVAL;
117 }
118
119 rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
120 rfkill->type, &rfkill_gpio_ops,
121 rfkill);
122 if (!rfkill->rfkill_dev)
123 return -ENOMEM;
124
125 ret = rfkill_register(rfkill->rfkill_dev);
126 if (ret < 0)
127 goto err_destroy;
128
129 platform_set_drvdata(pdev, rfkill);
130
131 dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
132
133 return 0;
134
135 err_destroy:
136 rfkill_destroy(rfkill->rfkill_dev);
137
138 return ret;
139 }
140
rfkill_gpio_remove(struct platform_device * pdev)141 static int rfkill_gpio_remove(struct platform_device *pdev)
142 {
143 struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
144
145 rfkill_unregister(rfkill->rfkill_dev);
146 rfkill_destroy(rfkill->rfkill_dev);
147
148 return 0;
149 }
150
151 #ifdef CONFIG_ACPI
152 static const struct acpi_device_id rfkill_acpi_match[] = {
153 { "BCM4752", RFKILL_TYPE_GPS },
154 { "LNV4752", RFKILL_TYPE_GPS },
155 { },
156 };
157 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
158 #endif
159
160 static struct platform_driver rfkill_gpio_driver = {
161 .probe = rfkill_gpio_probe,
162 .remove = rfkill_gpio_remove,
163 .driver = {
164 .name = "rfkill_gpio",
165 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
166 },
167 };
168
169 module_platform_driver(rfkill_gpio_driver);
170
171 MODULE_DESCRIPTION("gpio rfkill");
172 MODULE_AUTHOR("NVIDIA");
173 MODULE_LICENSE("GPL");
174