net/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/platform_device.h>
  12 #include <linux/clk.h>
  13 #include <linux/slab.h>
  14 #include <linux/acpi.h>
  15 #include <linux/gpio/consumer.h>
  16
  17 struct rfkill_gpio_data {
  18         const char              *name;
  19         enum rfkill_type        type;
  20         struct gpio_desc        *reset_gpio;
  21         struct gpio_desc        *shutdown_gpio;
  22
  23         struct rfkill           *rfkill_dev;
  24         struct clk              *clk;
  25
  26         bool                    clk_enabled;
  27 };
  28
  29 static int rfkill_gpio_set_power(void *data, bool blocked)
  30 {
  31         struct rfkill_gpio_data *rfkill = data;
  32
  33         if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
  34                 clk_enable(rfkill->clk);
  35
  36         gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
  37         gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
  38
  39         if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
  40                 clk_disable(rfkill->clk);
  41
  42         rfkill->clk_enabled = !blocked;
  43
  44         return 0;
  45 }
  46
  47 static const struct rfkill_ops rfkill_gpio_ops = {
  48         .set_block = rfkill_gpio_set_power,
  49 };
  50
  51 static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
  52 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
  53
  54 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
  55         { "reset-gpios", &reset_gpios, 1 },
  56         { "shutdown-gpios", &shutdown_gpios, 1 },
  57         { },
  58 };
  59
  60 static int rfkill_gpio_acpi_probe(struct device *dev,
  61                                   struct rfkill_gpio_data *rfkill)
  62 {
  63         const struct acpi_device_id *id;
  64
  65         id = acpi_match_device(dev->driver->acpi_match_table, dev);
  66         if (!id)
  67                 return -ENODEV;
  68
  69         rfkill->type = (unsigned)id->driver_data;
  70
  71         return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);
  72 }
  73
  74 static int rfkill_gpio_probe(struct platform_device *pdev)
  75 {
  76         struct rfkill_gpio_data *rfkill;
  77         struct gpio_desc *gpio;
  78         const char *name_property;
  79         const char *type_property;
  80         const char *type_name;
  81         int ret;
  82
  83         rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
  84         if (!rfkill)
  85                 return -ENOMEM;
  86
  87         if (dev_of_node(&pdev->dev)) {
  88                 name_property = "label";
  89                 type_property = "radio-type";
  90         } else {
  91                 name_property = "name";
  92                 type_property = "type";
  93         }
  94         device_property_read_string(&pdev->dev, name_property, &rfkill->name);
  95         device_property_read_string(&pdev->dev, type_property, &type_name);
  96
  97         if (!rfkill->name)
  98                 rfkill->name = dev_name(&pdev->dev);
  99
 100         rfkill->type = rfkill_find_type(type_name);
 101
 102         if (ACPI_HANDLE(&pdev->dev)) {
 103                 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
 104                 if (ret)
 105                         return ret;
 106         }
 107
 108         rfkill->clk = devm_clk_get(&pdev->dev, NULL);
 109
 110         gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
 111         if (IS_ERR(gpio))
 112                 return PTR_ERR(gpio);
 113
 114         rfkill->reset_gpio = gpio;
 115
 116         gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_OUT_LOW);
 117         if (IS_ERR(gpio))
 118                 return PTR_ERR(gpio);
 119
 120         rfkill->shutdown_gpio = gpio;
 121
 122         /* Make sure at-least one GPIO is defined for this instance */
 123         if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
 124                 dev_err(&pdev->dev, "invalid platform data\n");
 125                 return -EINVAL;
 126         }
 127
 128         rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
 129                                           rfkill->type, &rfkill_gpio_ops,
 130                                           rfkill);
 131         if (!rfkill->rfkill_dev)
 132                 return -ENOMEM;
 133
 134         ret = rfkill_register(rfkill->rfkill_dev);
 135         if (ret < 0)
 136                 goto err_destroy;
 137
 138         platform_set_drvdata(pdev, rfkill);
 139
 140         dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
 141
 142         return 0;
 143
 144 err_destroy:
 145         rfkill_destroy(rfkill->rfkill_dev);
 146
 147         return ret;
 148 }
 149
 150 static int rfkill_gpio_remove(struct platform_device *pdev)
 151 {
 152         struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
 153
 154         rfkill_unregister(rfkill->rfkill_dev);
 155         rfkill_destroy(rfkill->rfkill_dev);
 156
 157         return 0;
 158 }
 159
 160 #ifdef CONFIG_ACPI
 161 static const struct acpi_device_id rfkill_acpi_match[] = {
 162         { "BCM4752", RFKILL_TYPE_GPS },
 163         { "LNV4752", RFKILL_TYPE_GPS },
 164         { },
 165 };
 166 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
 167 #endif
 168
 169 static const struct of_device_id rfkill_of_match[] __maybe_unused = {
 170         { .compatible = "rfkill-gpio", },
 171         { },
 172 };
 173 MODULE_DEVICE_TABLE(of, rfkill_of_match);
 174
 175 static struct platform_driver rfkill_gpio_driver = {
 176         .probe = rfkill_gpio_probe,
 177         .remove = rfkill_gpio_remove,
 178         .driver = {
 179                 .name = "rfkill_gpio",
 180                 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
 181                 .of_match_table = of_match_ptr(rfkill_of_match),
 182         },
 183 };
 184
 185 module_platform_driver(rfkill_gpio_driver);
 186
 187 MODULE_DESCRIPTION("gpio rfkill");
 188 MODULE_AUTHOR("NVIDIA");
 189 MODULE_LICENSE("GPL");