drivers/leds/leds-nic78bx.c

   1 /*
   2  * Copyright (C) 2016 National Instruments Corp.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/acpi.h>
  16 #include <linux/leds.h>
  17 #include <linux/module.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/spinlock.h>
  20
  21 #define NIC78BX_USER1_LED_MASK          0x3
  22 #define NIC78BX_USER1_GREEN_LED         BIT(0)
  23 #define NIC78BX_USER1_YELLOW_LED        BIT(1)
  24
  25 #define NIC78BX_USER2_LED_MASK          0xC
  26 #define NIC78BX_USER2_GREEN_LED         BIT(2)
  27 #define NIC78BX_USER2_YELLOW_LED        BIT(3)
  28
  29 #define NIC78BX_LOCK_REG_OFFSET         1
  30 #define NIC78BX_LOCK_VALUE              0xA5
  31 #define NIC78BX_UNLOCK_VALUE            0x5A
  32
  33 #define NIC78BX_USER_LED_IO_SIZE        2
  34
  35 struct nic78bx_led_data {
  36         u16 io_base;
  37         spinlock_t lock;
  38         struct platform_device *pdev;
  39 };
  40
  41 struct nic78bx_led {
  42         u8 bit;
  43         u8 mask;
  44         struct nic78bx_led_data *data;
  45         struct led_classdev cdev;
  46 };
  47
  48 static inline struct nic78bx_led *to_nic78bx_led(struct led_classdev *cdev)
  49 {
  50         return container_of(cdev, struct nic78bx_led, cdev);
  51 }
  52
  53 static void nic78bx_brightness_set(struct led_classdev *cdev,
  54                                   enum led_brightness brightness)
  55 {
  56         struct nic78bx_led *nled = to_nic78bx_led(cdev);
  57         unsigned long flags;
  58         u8 value;
  59
  60         spin_lock_irqsave(&nled->data->lock, flags);
  61         value = inb(nled->data->io_base);
  62
  63         if (brightness) {
  64                 value &= ~nled->mask;
  65                 value |= nled->bit;
  66         } else {
  67                 value &= ~nled->bit;
  68         }
  69
  70         outb(value, nled->data->io_base);
  71         spin_unlock_irqrestore(&nled->data->lock, flags);
  72 }
  73
  74 static enum led_brightness nic78bx_brightness_get(struct led_classdev *cdev)
  75 {
  76         struct nic78bx_led *nled = to_nic78bx_led(cdev);
  77         unsigned long flags;
  78         u8 value;
  79
  80         spin_lock_irqsave(&nled->data->lock, flags);
  81         value = inb(nled->data->io_base);
  82         spin_unlock_irqrestore(&nled->data->lock, flags);
  83
  84         return (value & nled->bit) ? 1 : LED_OFF;
  85 }
  86
  87 static struct nic78bx_led nic78bx_leds[] = {
  88         {
  89                 .bit = NIC78BX_USER1_GREEN_LED,
  90                 .mask = NIC78BX_USER1_LED_MASK,
  91                 .cdev = {
  92                         .name = "nilrt:green:user1",
  93                         .max_brightness = 1,
  94                         .brightness_set = nic78bx_brightness_set,
  95                         .brightness_get = nic78bx_brightness_get,
  96                 }
  97         },
  98         {
  99                 .bit = NIC78BX_USER1_YELLOW_LED,
 100                 .mask = NIC78BX_USER1_LED_MASK,
 101                 .cdev = {
 102                         .name = "nilrt:yellow:user1",
 103                         .max_brightness = 1,
 104                         .brightness_set = nic78bx_brightness_set,
 105                         .brightness_get = nic78bx_brightness_get,
 106                 }
 107         },
 108         {
 109                 .bit = NIC78BX_USER2_GREEN_LED,
 110                 .mask = NIC78BX_USER2_LED_MASK,
 111                 .cdev = {
 112                         .name = "nilrt:green:user2",
 113                         .max_brightness = 1,
 114                         .brightness_set = nic78bx_brightness_set,
 115                         .brightness_get = nic78bx_brightness_get,
 116                 }
 117         },
 118         {
 119                 .bit = NIC78BX_USER2_YELLOW_LED,
 120                 .mask = NIC78BX_USER2_LED_MASK,
 121                 .cdev = {
 122                         .name = "nilrt:yellow:user2",
 123                         .max_brightness = 1,
 124                         .brightness_set = nic78bx_brightness_set,
 125                         .brightness_get = nic78bx_brightness_get,
 126                 }
 127         }
 128 };
 129
 130 static int nic78bx_probe(struct platform_device *pdev)
 131 {
 132         struct device *dev = &pdev->dev;
 133         struct nic78bx_led_data *led_data;
 134         struct resource *io_rc;
 135         int ret, i;
 136
 137         led_data = devm_kzalloc(dev, sizeof(*led_data), GFP_KERNEL);
 138         if (!led_data)
 139                 return -ENOMEM;
 140
 141         led_data->pdev = pdev;
 142         platform_set_drvdata(pdev, led_data);
 143
 144         io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);
 145         if (!io_rc) {
 146                 dev_err(dev, "missing IO resources\n");
 147                 return -EINVAL;
 148         }
 149
 150         if (resource_size(io_rc) < NIC78BX_USER_LED_IO_SIZE) {
 151                 dev_err(dev, "IO region too small\n");
 152                 return -EINVAL;
 153         }
 154
 155         if (!devm_request_region(dev, io_rc->start, resource_size(io_rc),
 156                                  KBUILD_MODNAME)) {
 157                 dev_err(dev, "failed to get IO region\n");
 158                 return -EBUSY;
 159         }
 160
 161         led_data->io_base = io_rc->start;
 162         spin_lock_init(&led_data->lock);
 163
 164         for (i = 0; i < ARRAY_SIZE(nic78bx_leds); i++) {
 165                 nic78bx_leds[i].data = led_data;
 166
 167                 ret = devm_led_classdev_register(dev, &nic78bx_leds[i].cdev);
 168                 if (ret)
 169                         return ret;
 170         }
 171
 172         /* Unlock LED register */
 173         outb(NIC78BX_UNLOCK_VALUE,
 174              led_data->io_base + NIC78BX_LOCK_REG_OFFSET);
 175
 176         return ret;
 177 }
 178
 179 static int nic78bx_remove(struct platform_device *pdev)
 180 {
 181         struct nic78bx_led_data *led_data = platform_get_drvdata(pdev);
 182
 183         /* Lock LED register */
 184         outb(NIC78BX_LOCK_VALUE,
 185              led_data->io_base + NIC78BX_LOCK_REG_OFFSET);
 186
 187         return 0;
 188 }
 189
 190 static const struct acpi_device_id led_device_ids[] = {
 191         {"NIC78B3", 0},
 192         {"", 0},
 193 };
 194 MODULE_DEVICE_TABLE(acpi, led_device_ids);
 195
 196 static struct platform_driver led_driver = {
 197         .probe = nic78bx_probe,
 198         .remove = nic78bx_remove,
 199         .driver = {
 200                 .name = KBUILD_MODNAME,
 201                 .acpi_match_table = ACPI_PTR(led_device_ids),
 202         },
 203 };
 204
 205 module_platform_driver(led_driver);
 206
 207 MODULE_DESCRIPTION("National Instruments PXI User LEDs driver");
 208 MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>");
 209 MODULE_LICENSE("GPL");