rfkill/rfkill-gpio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (c) 2011, NVIDIA Corporation.
   4  */
   5
   6 #include <linux/init.h>
   7 #include <linux/kernel.h>
   8 #include <linux/module.h>
   9 #include <linux/mod_devicetable.h>
  10 #include <linux/rfkill.h>
  11 #include <linux/of.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/clk.h>
  14 #include <linux/slab.h>
  15 #include <linux/acpi.h>
  16 #include <linux/gpio/consumer.h>
  17
  18 struct rfkill_gpio_data {
  19         const char              *name;
  20         enum rfkill_type        type;
  21         struct gpio_desc        *reset_gpio;
  22         struct gpio_desc        *shutdown_gpio;
  23
  24         struct rfkill           *rfkill_dev;
  25         struct clk              *clk;
  26
  27         bool                    clk_enabled;
  28 };
  29
  30 static int rfkill_gpio_set_power(void *data, bool blocked)
  31 {
  32         struct rfkill_gpio_data *rfkill = data;
  33
  34         if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
  35                 clk_enable(rfkill->clk);
  36
  37         gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
  38         gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
  39
  40         if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
  41                 clk_disable(rfkill->clk);
  42
  43         rfkill->clk_enabled = !blocked;
  44
  45         return 0;
  46 }
  47
  48 static const struct rfkill_ops rfkill_gpio_ops = {
  49         .set_block = rfkill_gpio_set_power,
  50 };
  51
  52 static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
  53 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
  54
  55 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
  56         { "reset-gpios", &reset_gpios, 1 },
  57         { "shutdown-gpios", &shutdown_gpios, 1 },
  58         { },
  59 };
  60
  61 static int rfkill_gpio_acpi_probe(struct device *dev,
  62                                   struct rfkill_gpio_data *rfkill)
  63 {
  64         const struct acpi_device_id *id;
  65
  66         id = acpi_match_device(dev->driver->acpi_match_table, dev);
  67         if (!id)
  68                 return -ENODEV;
  69
  70         rfkill->type = (unsigned)id->driver_data;
  71
  72         return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);
  73 }
  74
  75 static int rfkill_gpio_probe(struct platform_device *pdev)
  76 {
  77         struct rfkill_gpio_data *rfkill;
  78         struct gpio_desc *gpio;
  79         const char *name_property;
  80         const char *type_property;
  81         const char *type_name;
  82         int ret;
  83
  84         rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
  85         if (!rfkill)
  86                 return -ENOMEM;
  87
  88         if (dev_of_node(&pdev->dev)) {
  89                 name_property = "label";
  90                 type_property = "radio-type";
  91         } else {
  92                 name_property = "name";
  93                 type_property = "type";
  94         }
  95         device_property_read_string(&pdev->dev, name_property, &rfkill->name);
  96         device_property_read_string(&pdev->dev, type_property, &type_name);
  97
  98         if (!rfkill->name)
  99                 rfkill->name = dev_name(&pdev->dev);
 100
 101         rfkill->type = rfkill_find_type(type_name);
 102
 103         if (ACPI_HANDLE(&pdev->dev)) {
 104                 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
 105                 if (ret)
 106                         return ret;
 107         }
 108
 109         rfkill->clk = devm_clk_get(&pdev->dev, NULL);
 110
 111         gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS);
 112         if (IS_ERR(gpio))
 113                 return PTR_ERR(gpio);
 114
 115         rfkill->reset_gpio = gpio;
 116
 117         gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_ASIS);
 118         if (IS_ERR(gpio))
 119                 return PTR_ERR(gpio);
 120
 121         rfkill->shutdown_gpio = gpio;
 122
 123         /* Make sure at-least one GPIO is defined for this instance */
 124         if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
 125                 dev_err(&pdev->dev, "invalid platform data\n");
 126                 return -EINVAL;
 127         }
 128
 129         ret = gpiod_direction_output(rfkill->reset_gpio, true);
 130         if (ret)
 131                 return ret;
 132
 133         ret = gpiod_direction_output(rfkill->shutdown_gpio, true);
 134         if (ret)
 135                 return ret;
 136
 137         rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
 138                                           rfkill->type, &rfkill_gpio_ops,
 139                                           rfkill);
 140         if (!rfkill->rfkill_dev)
 141                 return -ENOMEM;
 142
 143         ret = rfkill_register(rfkill->rfkill_dev);
 144         if (ret < 0)
 145                 goto err_destroy;
 146
 147         platform_set_drvdata(pdev, rfkill);
 148
 149         dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
 150
 151         return 0;
 152
 153 err_destroy:
 154         rfkill_destroy(rfkill->rfkill_dev);
 155
 156         return ret;
 157 }
 158
 159 static int rfkill_gpio_remove(struct platform_device *pdev)
 160 {
 161         struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
 162
 163         rfkill_unregister(rfkill->rfkill_dev);
 164         rfkill_destroy(rfkill->rfkill_dev);
 165
 166         return 0;
 167 }
 168
 169 #ifdef CONFIG_ACPI
 170 static const struct acpi_device_id rfkill_acpi_match[] = {
 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 const struct of_device_id rfkill_of_match[] __maybe_unused = {
 179         { .compatible = "rfkill-gpio", },
 180         { },
 181 };
 182 MODULE_DEVICE_TABLE(of, rfkill_of_match);
 183
 184 static struct platform_driver rfkill_gpio_driver = {
 185         .probe = rfkill_gpio_probe,
 186         .remove = rfkill_gpio_remove,
 187         .driver = {
 188                 .name = "rfkill_gpio",
 189                 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
 190                 .of_match_table = of_match_ptr(rfkill_of_match),
 191         },
 192 };
 193
 194 module_platform_driver(rfkill_gpio_driver);
 195
 196 MODULE_DESCRIPTION("gpio rfkill");
 197 MODULE_AUTHOR("NVIDIA");
 198 MODULE_LICENSE("GPL");