drivers/leds/leds-nic78bx.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2016 National Instruments Corp.
   4  */
   5
   6 #include <linux/acpi.h>
   7 #include <linux/leds.h>
   8 #include <linux/module.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/spinlock.h>
  11
  12 #define NIC78BX_USER1_LED_MASK          0x3
  13 #define NIC78BX_USER1_GREEN_LED         BIT(0)
  14 #define NIC78BX_USER1_YELLOW_LED        BIT(1)
  15
  16 #define NIC78BX_USER2_LED_MASK          0xC
  17 #define NIC78BX_USER2_GREEN_LED         BIT(2)
  18 #define NIC78BX_USER2_YELLOW_LED        BIT(3)
  19
  20 #define NIC78BX_LOCK_REG_OFFSET         1
  21 #define NIC78BX_LOCK_VALUE              0xA5
  22 #define NIC78BX_UNLOCK_VALUE            0x5A
  23
  24 #define NIC78BX_USER_LED_IO_SIZE        2
  25
  26 struct nic78bx_led_data {
  27         u16 io_base;
  28         spinlock_t lock;
  29         struct platform_device *pdev;
  30 };
  31
  32 struct nic78bx_led {
  33         u8 bit;
  34         u8 mask;
  35         struct nic78bx_led_data *data;
  36         struct led_classdev cdev;
  37 };
  38
  39 static inline struct nic78bx_led *to_nic78bx_led(struct led_classdev *cdev)
  40 {
  41         return container_of(cdev, struct nic78bx_led, cdev);
  42 }
  43
  44 static void nic78bx_brightness_set(struct led_classdev *cdev,
  45                                   enum led_brightness brightness)
  46 {
  47         struct nic78bx_led *nled = to_nic78bx_led(cdev);
  48         unsigned long flags;
  49         u8 value;
  50
  51         spin_lock_irqsave(&nled->data->lock, flags);
  52         value = inb(nled->data->io_base);
  53
  54         if (brightness) {
  55                 value &= ~nled->mask;
  56                 value |= nled->bit;
  57         } else {
  58                 value &= ~nled->bit;
  59         }
  60
  61         outb(value, nled->data->io_base);
  62         spin_unlock_irqrestore(&nled->data->lock, flags);
  63 }
  64
  65 static enum led_brightness nic78bx_brightness_get(struct led_classdev *cdev)
  66 {
  67         struct nic78bx_led *nled = to_nic78bx_led(cdev);
  68         unsigned long flags;
  69         u8 value;
  70
  71         spin_lock_irqsave(&nled->data->lock, flags);
  72         value = inb(nled->data->io_base);
  73         spin_unlock_irqrestore(&nled->data->lock, flags);
  74
  75         return (value & nled->bit) ? 1 : LED_OFF;
  76 }
  77
  78 static struct nic78bx_led nic78bx_leds[] = {
  79         {
  80                 .bit = NIC78BX_USER1_GREEN_LED,
  81                 .mask = NIC78BX_USER1_LED_MASK,
  82                 .cdev = {
  83                         .name = "nilrt:green:user1",
  84                         .max_brightness = 1,
  85                         .brightness_set = nic78bx_brightness_set,
  86                         .brightness_get = nic78bx_brightness_get,
  87                 }
  88         },
  89         {
  90                 .bit = NIC78BX_USER1_YELLOW_LED,
  91                 .mask = NIC78BX_USER1_LED_MASK,
  92                 .cdev = {
  93                         .name = "nilrt:yellow:user1",
  94                         .max_brightness = 1,
  95                         .brightness_set = nic78bx_brightness_set,
  96                         .brightness_get = nic78bx_brightness_get,
  97                 }
  98         },
  99         {
 100                 .bit = NIC78BX_USER2_GREEN_LED,
 101                 .mask = NIC78BX_USER2_LED_MASK,
 102                 .cdev = {
 103                         .name = "nilrt:green:user2",
 104                         .max_brightness = 1,
 105                         .brightness_set = nic78bx_brightness_set,
 106                         .brightness_get = nic78bx_brightness_get,
 107                 }
 108         },
 109         {
 110                 .bit = NIC78BX_USER2_YELLOW_LED,
 111                 .mask = NIC78BX_USER2_LED_MASK,
 112                 .cdev = {
 113                         .name = "nilrt:yellow:user2",
 114                         .max_brightness = 1,
 115                         .brightness_set = nic78bx_brightness_set,
 116                         .brightness_get = nic78bx_brightness_get,
 117                 }
 118         }
 119 };
 120
 121 static void lock_led_reg_action(void *data)
 122 {
 123         struct nic78bx_led_data *led_data = data;
 124
 125         /* Lock LED register */
 126         outb(NIC78BX_LOCK_VALUE,
 127              led_data->io_base + NIC78BX_LOCK_REG_OFFSET);
 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         ret = devm_add_action(dev, lock_led_reg_action, led_data);
 165         if (ret)
 166                 return ret;
 167
 168         for (i = 0; i < ARRAY_SIZE(nic78bx_leds); i++) {
 169                 nic78bx_leds[i].data = led_data;
 170
 171                 ret = devm_led_classdev_register(dev, &nic78bx_leds[i].cdev);
 172                 if (ret)
 173                         return ret;
 174         }
 175
 176         /* Unlock LED register */
 177         outb(NIC78BX_UNLOCK_VALUE,
 178              led_data->io_base + NIC78BX_LOCK_REG_OFFSET);
 179
 180         return ret;
 181 }
 182
 183 static const struct acpi_device_id led_device_ids[] = {
 184         {"NIC78B3", 0},
 185         {"", 0},
 186 };
 187 MODULE_DEVICE_TABLE(acpi, led_device_ids);
 188
 189 static struct platform_driver led_driver = {
 190         .probe = nic78bx_probe,
 191         .driver = {
 192                 .name = KBUILD_MODNAME,
 193                 .acpi_match_table = ACPI_PTR(led_device_ids),
 194         },
 195 };
 196
 197 module_platform_driver(led_driver);
 198
 199 MODULE_DESCRIPTION("National Instruments PXI User LEDs driver");
 200 MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>");
 201 MODULE_LICENSE("GPL");