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