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/dmi.h>
   7 #include <linux/init.h>
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/mod_devicetable.h>
  11 #include <linux/rfkill.h>
  12 #include <linux/of.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/clk.h>
  15 #include <linux/slab.h>
  16 #include <linux/acpi.h>
  17 #include <linux/gpio/consumer.h>
  18
  19 struct rfkill_gpio_data {
  20         const char              *name;
  21         enum rfkill_type        type;
  22         struct gpio_desc        *reset_gpio;
  23         struct gpio_desc        *shutdown_gpio;
  24
  25         struct rfkill           *rfkill_dev;
  26         struct clk              *clk;
  27
  28         bool                    clk_enabled;
  29 };
  30
  31 static int rfkill_gpio_set_power(void *data, bool blocked)
  32 {
  33         struct rfkill_gpio_data *rfkill = data;
  34
  35         if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled) {
  36                 int ret = clk_enable(rfkill->clk);
  37
  38                 if (ret)
  39                         return ret;
  40         }
  41
  42         gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
  43         gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
  44
  45         if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
  46                 clk_disable(rfkill->clk);
  47
  48         rfkill->clk_enabled = !blocked;
  49
  50         return 0;
  51 }
  52
  53 static const struct rfkill_ops rfkill_gpio_ops = {
  54         .set_block = rfkill_gpio_set_power,
  55 };
  56
  57 static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
  58 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
  59
  60 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
  61         { "reset-gpios", &reset_gpios, 1 },
  62         { "shutdown-gpios", &shutdown_gpios, 1 },
  63         { },
  64 };
  65
  66 static int rfkill_gpio_acpi_probe(struct device *dev,
  67                                   struct rfkill_gpio_data *rfkill)
  68 {
  69         const struct acpi_device_id *id;
  70
  71         id = acpi_match_device(dev->driver->acpi_match_table, dev);
  72         if (!id)
  73                 return -ENODEV;
  74
  75         rfkill->type = (unsigned)id->driver_data;
  76
  77         return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);
  78 }
  79
  80 /* List of DMI matches for devices on which rfkill-gpio should not load,
  81  * to avoid firmware bugs.
  82  */
  83 static const struct dmi_system_id rfkill_gpio_deny_table[] = {
  84         {
  85                 /* Lenovo Yoga Tab 3 Pro YT3-X90, bogus "BCM4752" device in DSDT */
  86                 .matches = {
  87                         DMI_MATCH(DMI_SYS_VENDOR, "Intel Corporation"),
  88                         DMI_MATCH(DMI_PRODUCT_VERSION, "Blade3-10A-001"),
  89                 },
  90         },
  91         { }
  92 };
  93
  94 static int rfkill_gpio_probe(struct platform_device *pdev)
  95 {
  96         struct rfkill_gpio_data *rfkill;
  97         struct gpio_desc *gpio;
  98         const char *name_property;
  99         const char *type_property;
 100         const char *type_name;
 101         int ret;
 102
 103         if (dmi_check_system(rfkill_gpio_deny_table))
 104                 return -ENODEV;
 105
 106         rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
 107         if (!rfkill)
 108                 return -ENOMEM;
 109
 110         if (dev_of_node(&pdev->dev)) {
 111                 name_property = "label";
 112                 type_property = "radio-type";
 113         } else {
 114                 name_property = "name";
 115                 type_property = "type";
 116         }
 117         device_property_read_string(&pdev->dev, name_property, &rfkill->name);
 118         device_property_read_string(&pdev->dev, type_property, &type_name);
 119
 120         if (!rfkill->name)
 121                 rfkill->name = dev_name(&pdev->dev);
 122
 123         rfkill->type = rfkill_find_type(type_name);
 124
 125         if (ACPI_HANDLE(&pdev->dev)) {
 126                 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
 127                 if (ret)
 128                         return ret;
 129         }
 130
 131         rfkill->clk = devm_clk_get(&pdev->dev, NULL);
 132
 133         gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS);
 134         if (IS_ERR(gpio))
 135                 return PTR_ERR(gpio);
 136
 137         rfkill->reset_gpio = gpio;
 138
 139         gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_ASIS);
 140         if (IS_ERR(gpio))
 141                 return PTR_ERR(gpio);
 142
 143         rfkill->shutdown_gpio = gpio;
 144
 145         /* Make sure at-least one GPIO is defined for this instance */
 146         if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
 147                 dev_err(&pdev->dev, "invalid platform data\n");
 148                 return -EINVAL;
 149         }
 150
 151         ret = gpiod_direction_output(rfkill->reset_gpio, true);
 152         if (ret)
 153                 return ret;
 154
 155         ret = gpiod_direction_output(rfkill->shutdown_gpio, true);
 156         if (ret)
 157                 return ret;
 158
 159         rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
 160                                           rfkill->type, &rfkill_gpio_ops,
 161                                           rfkill);
 162         if (!rfkill->rfkill_dev)
 163                 return -ENOMEM;
 164
 165         ret = rfkill_register(rfkill->rfkill_dev);
 166         if (ret < 0)
 167                 goto err_destroy;
 168
 169         platform_set_drvdata(pdev, rfkill);
 170
 171         dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
 172
 173         return 0;
 174
 175 err_destroy:
 176         rfkill_destroy(rfkill->rfkill_dev);
 177
 178         return ret;
 179 }
 180
 181 static void rfkill_gpio_remove(struct platform_device *pdev)
 182 {
 183         struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
 184
 185         rfkill_unregister(rfkill->rfkill_dev);
 186         rfkill_destroy(rfkill->rfkill_dev);
 187 }
 188
 189 #ifdef CONFIG_ACPI
 190 static const struct acpi_device_id rfkill_acpi_match[] = {
 191         { "BCM4752", RFKILL_TYPE_GPS },
 192         { "LNV4752", RFKILL_TYPE_GPS },
 193         { },
 194 };
 195 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
 196 #endif
 197
 198 static const struct of_device_id rfkill_of_match[] __maybe_unused = {
 199         { .compatible = "rfkill-gpio", },
 200         { },
 201 };
 202 MODULE_DEVICE_TABLE(of, rfkill_of_match);
 203
 204 static struct platform_driver rfkill_gpio_driver = {
 205         .probe = rfkill_gpio_probe,
 206         .remove = rfkill_gpio_remove,
 207         .driver = {
 208                 .name = "rfkill_gpio",
 209                 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
 210                 .of_match_table = of_match_ptr(rfkill_of_match),
 211         },
 212 };
 213
 214 module_platform_driver(rfkill_gpio_driver);
 215
 216 MODULE_DESCRIPTION("gpio rfkill");
 217 MODULE_AUTHOR("NVIDIA");
 218 MODULE_LICENSE("GPL");