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         char                    *reset_name;
  40         char                    *shutdown_name;
  41         struct clk              *clk;
  42
  43         bool                    clk_enabled;
  44 };
  45
  46 static int rfkill_gpio_set_power(void *data, bool blocked)
  47 {
  48         struct rfkill_gpio_data *rfkill = data;
  49
  50         if (blocked) {
  51                 gpiod_set_value(rfkill->shutdown_gpio, 0);
  52                 gpiod_set_value(rfkill->reset_gpio, 0);
  53                 if (!IS_ERR(rfkill->clk) && rfkill->clk_enabled)
  54                         clk_disable(rfkill->clk);
  55         } else {
  56                 if (!IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
  57                         clk_enable(rfkill->clk);
  58                 gpiod_set_value(rfkill->reset_gpio, 1);
  59                 gpiod_set_value(rfkill->shutdown_gpio, 1);
  60         }
  61
  62         rfkill->clk_enabled = blocked;
  63
  64         return 0;
  65 }
  66
  67 static const struct rfkill_ops rfkill_gpio_ops = {
  68         .set_block = rfkill_gpio_set_power,
  69 };
  70
  71 static int rfkill_gpio_acpi_probe(struct device *dev,
  72                                   struct rfkill_gpio_data *rfkill)
  73 {
  74         const struct acpi_device_id *id;
  75
  76         id = acpi_match_device(dev->driver->acpi_match_table, dev);
  77         if (!id)
  78                 return -ENODEV;
  79
  80         rfkill->name = dev_name(dev);
  81         rfkill->type = (unsigned)id->driver_data;
  82
  83         return 0;
  84 }
  85
  86 static int rfkill_gpio_probe(struct platform_device *pdev)
  87 {
  88         struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
  89         struct rfkill_gpio_data *rfkill;
  90         const char *clk_name = NULL;
  91         struct gpio_desc *gpio;
  92         int ret;
  93         int len;
  94
  95         rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
  96         if (!rfkill)
  97                 return -ENOMEM;
  98
  99         if (ACPI_HANDLE(&pdev->dev)) {
 100                 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
 101                 if (ret)
 102                         return ret;
 103         } else if (pdata) {
 104                 clk_name = pdata->power_clk_name;
 105                 rfkill->name = pdata->name;
 106                 rfkill->type = pdata->type;
 107         } else {
 108                 return -ENODEV;
 109         }
 110
 111         len = strlen(rfkill->name);
 112         rfkill->reset_name = devm_kzalloc(&pdev->dev, len + 7, GFP_KERNEL);
 113         if (!rfkill->reset_name)
 114                 return -ENOMEM;
 115
 116         rfkill->shutdown_name = devm_kzalloc(&pdev->dev, len + 10, GFP_KERNEL);
 117         if (!rfkill->shutdown_name)
 118                 return -ENOMEM;
 119
 120         snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name);
 121         snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name);
 122
 123         rfkill->clk = devm_clk_get(&pdev->dev, clk_name);
 124
 125         gpio = devm_gpiod_get_index(&pdev->dev, rfkill->reset_name, 0);
 126         if (!IS_ERR(gpio)) {
 127                 ret = gpiod_direction_output(gpio, 0);
 128                 if (ret)
 129                         return ret;
 130                 rfkill->reset_gpio = gpio;
 131         }
 132
 133         gpio = devm_gpiod_get_index(&pdev->dev, rfkill->shutdown_name, 1);
 134         if (!IS_ERR(gpio)) {
 135                 ret = gpiod_direction_output(gpio, 0);
 136                 if (ret)
 137                         return ret;
 138                 rfkill->shutdown_gpio = gpio;
 139         }
 140
 141         /* Make sure at-least one of the GPIO is defined and that
 142          * a name is specified for this instance
 143          */
 144         if ((!rfkill->reset_gpio && !rfkill->shutdown_gpio) || !rfkill->name) {
 145                 dev_err(&pdev->dev, "invalid platform data\n");
 146                 return -EINVAL;
 147         }
 148
 149         if (pdata && pdata->gpio_runtime_setup) {
 150                 ret = pdata->gpio_runtime_setup(pdev);
 151                 if (ret) {
 152                         dev_err(&pdev->dev, "can't set up gpio\n");
 153                         return ret;
 154                 }
 155         }
 156
 157         rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
 158                                           rfkill->type, &rfkill_gpio_ops,
 159                                           rfkill);
 160         if (!rfkill->rfkill_dev)
 161                 return -ENOMEM;
 162
 163         ret = rfkill_register(rfkill->rfkill_dev);
 164         if (ret < 0)
 165                 return ret;
 166
 167         platform_set_drvdata(pdev, rfkill);
 168
 169         dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
 170
 171         return 0;
 172 }
 173
 174 static int rfkill_gpio_remove(struct platform_device *pdev)
 175 {
 176         struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
 177         struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
 178
 179         if (pdata && pdata->gpio_runtime_close)
 180                 pdata->gpio_runtime_close(pdev);
 181         rfkill_unregister(rfkill->rfkill_dev);
 182         rfkill_destroy(rfkill->rfkill_dev);
 183
 184         return 0;
 185 }
 186
 187 static const struct acpi_device_id rfkill_acpi_match[] = {
 188         { "BCM4752", RFKILL_TYPE_GPS },
 189         { },
 190 };
 191
 192 static struct platform_driver rfkill_gpio_driver = {
 193         .probe = rfkill_gpio_probe,
 194         .remove = rfkill_gpio_remove,
 195         .driver = {
 196                 .name = "rfkill_gpio",
 197                 .owner = THIS_MODULE,
 198                 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
 199         },
 200 };
 201
 202 module_platform_driver(rfkill_gpio_driver);
 203
 204 MODULE_DESCRIPTION("gpio rfkill");
 205 MODULE_AUTHOR("NVIDIA");
 206 MODULE_LICENSE("GPL");