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/acpi_gpio.h>
  29
  30 #include <linux/rfkill-gpio.h>
  31
  32 struct rfkill_gpio_data {
  33         const char              *name;
  34         enum rfkill_type        type;
  35         int                     reset_gpio;
  36         int                     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                 if (gpio_is_valid(rfkill->shutdown_gpio))
  52                         gpio_set_value(rfkill->shutdown_gpio, 0);
  53                 if (gpio_is_valid(rfkill->reset_gpio))
  54                         gpio_set_value(rfkill->reset_gpio, 0);
  55                 if (!IS_ERR(rfkill->clk) && rfkill->clk_enabled)
  56                         clk_disable(rfkill->clk);
  57         } else {
  58                 if (!IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
  59                         clk_enable(rfkill->clk);
  60                 if (gpio_is_valid(rfkill->reset_gpio))
  61                         gpio_set_value(rfkill->reset_gpio, 1);
  62                 if (gpio_is_valid(rfkill->shutdown_gpio))
  63                         gpio_set_value(rfkill->shutdown_gpio, 1);
  64         }
  65
  66         rfkill->clk_enabled = blocked;
  67
  68         return 0;
  69 }
  70
  71 static const struct rfkill_ops rfkill_gpio_ops = {
  72         .set_block = rfkill_gpio_set_power,
  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         rfkill->reset_gpio = acpi_get_gpio_by_index(dev, 0, NULL);
  87         rfkill->shutdown_gpio = acpi_get_gpio_by_index(dev, 1, NULL);
  88
  89         return 0;
  90 }
  91
  92 static int rfkill_gpio_probe(struct platform_device *pdev)
  93 {
  94         struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
  95         struct rfkill_gpio_data *rfkill;
  96         const char *clk_name = NULL;
  97         int ret = 0;
  98         int len = 0;
  99
 100         rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
 101         if (!rfkill)
 102                 return -ENOMEM;
 103
 104         if (ACPI_HANDLE(&pdev->dev)) {
 105                 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
 106                 if (ret)
 107                         return ret;
 108         } else if (pdata) {
 109                 clk_name = pdata->power_clk_name;
 110                 rfkill->name = pdata->name;
 111                 rfkill->type = pdata->type;
 112                 rfkill->reset_gpio = pdata->reset_gpio;
 113                 rfkill->shutdown_gpio = pdata->shutdown_gpio;
 114         } else {
 115                 return -ENODEV;
 116         }
 117
 118         /* make sure at-least one of the GPIO is defined and that
 119          * a name is specified for this instance */
 120         if ((!gpio_is_valid(rfkill->reset_gpio) &&
 121              !gpio_is_valid(rfkill->shutdown_gpio)) || !rfkill->name) {
 122                 pr_warn("%s: invalid platform data\n", __func__);
 123                 return -EINVAL;
 124         }
 125
 126         if (pdata && pdata->gpio_runtime_setup) {
 127                 ret = pdata->gpio_runtime_setup(pdev);
 128                 if (ret) {
 129                         pr_warn("%s: can't set up gpio\n", __func__);
 130                         return ret;
 131                 }
 132         }
 133
 134         len = strlen(rfkill->name);
 135         rfkill->reset_name = devm_kzalloc(&pdev->dev, len + 7, GFP_KERNEL);
 136         if (!rfkill->reset_name)
 137                 return -ENOMEM;
 138
 139         rfkill->shutdown_name = devm_kzalloc(&pdev->dev, len + 10, GFP_KERNEL);
 140         if (!rfkill->shutdown_name)
 141                 return -ENOMEM;
 142
 143         snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name);
 144         snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name);
 145
 146         rfkill->clk = devm_clk_get(&pdev->dev, clk_name);
 147
 148         if (gpio_is_valid(rfkill->reset_gpio)) {
 149                 ret = devm_gpio_request_one(&pdev->dev, rfkill->reset_gpio,
 150                                             0, rfkill->reset_name);
 151                 if (ret) {
 152                         pr_warn("%s: failed to get reset gpio.\n", __func__);
 153                         return ret;
 154                 }
 155         }
 156
 157         if (gpio_is_valid(rfkill->shutdown_gpio)) {
 158                 ret = devm_gpio_request_one(&pdev->dev, rfkill->shutdown_gpio,
 159                                             0, rfkill->shutdown_name);
 160                 if (ret) {
 161                         pr_warn("%s: failed to get shutdown gpio.\n", __func__);
 162                         return ret;
 163                 }
 164         }
 165
 166         rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
 167                                           rfkill->type, &rfkill_gpio_ops,
 168                                           rfkill);
 169         if (!rfkill->rfkill_dev)
 170                 return -ENOMEM;
 171
 172         ret = rfkill_register(rfkill->rfkill_dev);
 173         if (ret < 0)
 174                 return ret;
 175
 176         platform_set_drvdata(pdev, rfkill);
 177
 178         dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
 179
 180         return 0;
 181 }
 182
 183 static int rfkill_gpio_remove(struct platform_device *pdev)
 184 {
 185         struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
 186         struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
 187
 188         if (pdata && pdata->gpio_runtime_close)
 189                 pdata->gpio_runtime_close(pdev);
 190         rfkill_unregister(rfkill->rfkill_dev);
 191         rfkill_destroy(rfkill->rfkill_dev);
 192
 193         return 0;
 194 }
 195
 196 static const struct acpi_device_id rfkill_acpi_match[] = {
 197         { "BCM4752", RFKILL_TYPE_GPS },
 198         { },
 199 };
 200
 201 static struct platform_driver rfkill_gpio_driver = {
 202         .probe = rfkill_gpio_probe,
 203         .remove = rfkill_gpio_remove,
 204         .driver = {
 205                 .name = "rfkill_gpio",
 206                 .owner = THIS_MODULE,
 207                 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
 208         },
 209 };
 210
 211 module_platform_driver(rfkill_gpio_driver);
 212
 213 MODULE_DESCRIPTION("gpio rfkill");
 214 MODULE_AUTHOR("NVIDIA");
 215 MODULE_LICENSE("GPL");