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 *type_name;
  79         int ret;
  80
  81         rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
  82         if (!rfkill)
  83                 return -ENOMEM;
  84
  85         device_property_read_string(&pdev->dev, "name", &rfkill->name);
  86         device_property_read_string(&pdev->dev, "type", &type_name);
  87
  88         if (!rfkill->name)
  89                 rfkill->name = dev_name(&pdev->dev);
  90
  91         rfkill->type = rfkill_find_type(type_name);
  92
  93         if (ACPI_HANDLE(&pdev->dev)) {
  94                 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
  95                 if (ret)
  96                         return ret;
  97         }
  98
  99         rfkill->clk = devm_clk_get(&pdev->dev, NULL);
 100
 101         gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS);
 102         if (IS_ERR(gpio))
 103                 return PTR_ERR(gpio);
 104
 105         rfkill->reset_gpio = gpio;
 106
 107         gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_ASIS);
 108         if (IS_ERR(gpio))
 109                 return PTR_ERR(gpio);
 110
 111         rfkill->shutdown_gpio = gpio;
 112
 113         /* Make sure at-least one GPIO is defined for this instance */
 114         if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
 115                 dev_err(&pdev->dev, "invalid platform data\n");
 116                 return -EINVAL;
 117         }
 118
 119         ret = gpiod_direction_output(rfkill->reset_gpio, true);
 120         if (ret)
 121                 return ret;
 122
 123         ret = gpiod_direction_output(rfkill->shutdown_gpio, true);
 124         if (ret)
 125                 return ret;
 126
 127         rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
 128                                           rfkill->type, &rfkill_gpio_ops,
 129                                           rfkill);
 130         if (!rfkill->rfkill_dev)
 131                 return -ENOMEM;
 132
 133         ret = rfkill_register(rfkill->rfkill_dev);
 134         if (ret < 0)
 135                 goto err_destroy;
 136
 137         platform_set_drvdata(pdev, rfkill);
 138
 139         dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
 140
 141         return 0;
 142
 143 err_destroy:
 144         rfkill_destroy(rfkill->rfkill_dev);
 145
 146         return ret;
 147 }
 148
 149 static int rfkill_gpio_remove(struct platform_device *pdev)
 150 {
 151         struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
 152
 153         rfkill_unregister(rfkill->rfkill_dev);
 154         rfkill_destroy(rfkill->rfkill_dev);
 155
 156         return 0;
 157 }
 158
 159 #ifdef CONFIG_ACPI
 160 static const struct acpi_device_id rfkill_acpi_match[] = {
 161         { "BCM4752", RFKILL_TYPE_GPS },
 162         { "LNV4752", RFKILL_TYPE_GPS },
 163         { },
 164 };
 165 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
 166 #endif
 167
 168 static struct platform_driver rfkill_gpio_driver = {
 169         .probe = rfkill_gpio_probe,
 170         .remove = rfkill_gpio_remove,
 171         .driver = {
 172                 .name = "rfkill_gpio",
 173                 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
 174         },
 175 };
 176
 177 module_platform_driver(rfkill_gpio_driver);
 178
 179 MODULE_DESCRIPTION("gpio rfkill");
 180 MODULE_AUTHOR("NVIDIA");
 181 MODULE_LICENSE("GPL");