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 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->name = dev_name(dev);
  76         rfkill->type = (unsigned)id->driver_data;
  77
  78         return 0;
  79 }
  80
  81 static int rfkill_gpio_probe(struct platform_device *pdev)
  82 {
  83         struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
  84         struct rfkill_gpio_data *rfkill;
  85         struct gpio_desc *gpio;
  86         int ret;
  87
  88         rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
  89         if (!rfkill)
  90                 return -ENOMEM;
  91
  92         if (ACPI_HANDLE(&pdev->dev)) {
  93                 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
  94                 if (ret)
  95                         return ret;
  96         } else if (pdata) {
  97                 rfkill->name = pdata->name;
  98                 rfkill->type = pdata->type;
  99         } else {
 100                 return -ENODEV;
 101         }
 102
 103         rfkill->clk = devm_clk_get(&pdev->dev, NULL);
 104
 105         gpio = devm_gpiod_get_index(&pdev->dev, "reset", 0);
 106         if (!IS_ERR(gpio)) {
 107                 ret = gpiod_direction_output(gpio, 0);
 108                 if (ret)
 109                         return ret;
 110                 rfkill->reset_gpio = gpio;
 111         }
 112
 113         gpio = devm_gpiod_get_index(&pdev->dev, "shutdown", 1);
 114         if (!IS_ERR(gpio)) {
 115                 ret = gpiod_direction_output(gpio, 0);
 116                 if (ret)
 117                         return ret;
 118                 rfkill->shutdown_gpio = gpio;
 119         }
 120
 121         /* Make sure at-least one of the GPIO is defined and that
 122          * a name is specified for this instance
 123          */
 124         if ((!rfkill->reset_gpio && !rfkill->shutdown_gpio) || !rfkill->name) {
 125                 dev_err(&pdev->dev, "invalid platform data\n");
 126                 return -EINVAL;
 127         }
 128
 129         rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
 130                                           rfkill->type, &rfkill_gpio_ops,
 131                                           rfkill);
 132         if (!rfkill->rfkill_dev)
 133                 return -ENOMEM;
 134
 135         ret = rfkill_register(rfkill->rfkill_dev);
 136         if (ret < 0)
 137                 return ret;
 138
 139         platform_set_drvdata(pdev, rfkill);
 140
 141         dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
 142
 143         return 0;
 144 }
 145
 146 static int rfkill_gpio_remove(struct platform_device *pdev)
 147 {
 148         struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
 149
 150         rfkill_unregister(rfkill->rfkill_dev);
 151         rfkill_destroy(rfkill->rfkill_dev);
 152
 153         return 0;
 154 }
 155
 156 #ifdef CONFIG_ACPI
 157 static const struct acpi_device_id rfkill_acpi_match[] = {
 158         { "BCM2E1A", RFKILL_TYPE_BLUETOOTH },
 159         { "BCM2E39", RFKILL_TYPE_BLUETOOTH },
 160         { "BCM2E3D", RFKILL_TYPE_BLUETOOTH },
 161         { "BCM4752", RFKILL_TYPE_GPS },
 162         { "LNV4752", RFKILL_TYPE_GPS },
 163         { },
 164 };
 165 #endif
 166
 167 static struct platform_driver rfkill_gpio_driver = {
 168         .probe = rfkill_gpio_probe,
 169         .remove = rfkill_gpio_remove,
 170         .driver = {
 171                 .name = "rfkill_gpio",
 172                 .owner = THIS_MODULE,
 173                 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
 174         },
 175 };
 176
 177 module_platform_driver(rfkill_gpio_driver);
 178
 179 MODULE_DESCRIPTION("gpio rfkill");
 180 MODULE_AUTHOR("NVIDIA");
 181 MODULE_LICENSE("GPL");