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Linux/net/rfkill/rfkill-gpio.c

  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_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 of the GPIO is defined and that
128          * a name is specified for this instance
129          */
130         if ((!rfkill->reset_gpio && !rfkill->shutdown_gpio) || !rfkill->name) {
131                 dev_err(&pdev->dev, "invalid platform data\n");
132                 return -EINVAL;
133         }
134 
135         rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
136                                           rfkill->type, &rfkill_gpio_ops,
137                                           rfkill);
138         if (!rfkill->rfkill_dev)
139                 return -ENOMEM;
140 
141         ret = rfkill_register(rfkill->rfkill_dev);
142         if (ret < 0)
143                 return ret;
144 
145         platform_set_drvdata(pdev, rfkill);
146 
147         dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
148 
149         return 0;
150 }
151 
152 static int rfkill_gpio_remove(struct platform_device *pdev)
153 {
154         struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
155 
156         rfkill_unregister(rfkill->rfkill_dev);
157         rfkill_destroy(rfkill->rfkill_dev);
158 
159         acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->dev));
160 
161         return 0;
162 }
163 
164 #ifdef CONFIG_ACPI
165 static const struct acpi_device_id rfkill_acpi_match[] = {
166         { "BCM4752", RFKILL_TYPE_GPS },
167         { "LNV4752", RFKILL_TYPE_GPS },
168         { },
169 };
170 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
171 #endif
172 
173 static struct platform_driver rfkill_gpio_driver = {
174         .probe = rfkill_gpio_probe,
175         .remove = rfkill_gpio_remove,
176         .driver = {
177                 .name = "rfkill_gpio",
178                 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
179         },
180 };
181 
182 module_platform_driver(rfkill_gpio_driver);
183 
184 MODULE_DESCRIPTION("gpio rfkill");
185 MODULE_AUTHOR("NVIDIA");
186 MODULE_LICENSE("GPL");
187 

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