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         { "BCM2E1A", RFKILL_TYPE_BLUETOOTH },
 167         { "BCM2E39", RFKILL_TYPE_BLUETOOTH },
 168         { "BCM2E3D", RFKILL_TYPE_BLUETOOTH },
 169         { "BCM2E40", RFKILL_TYPE_BLUETOOTH },
 170         { "BCM2E64", RFKILL_TYPE_BLUETOOTH },
 171         { "BCM4752", RFKILL_TYPE_GPS },
 172         { "LNV4752", RFKILL_TYPE_GPS },
 173         { },
 174 };
 175 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
 176 #endif
 177
 178 static struct platform_driver rfkill_gpio_driver = {
 179         .probe = rfkill_gpio_probe,
 180         .remove = rfkill_gpio_remove,
 181         .driver = {
 182                 .name = "rfkill_gpio",
 183                 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
 184         },
 185 };
 186
 187 module_platform_driver(rfkill_gpio_driver);
 188
 189 MODULE_DESCRIPTION("gpio rfkill");
 190 MODULE_AUTHOR("NVIDIA");
 191 MODULE_LICENSE("GPL");