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