drivers/led/led_gpio.c

   1 /*
   2  * Copyright (c) 2015 Google, Inc
   3  * Written by Simon Glass <sjg@chromium.org>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <errno.h>
  11 #include <led.h>
  12 #include <asm/gpio.h>
  13 #include <dm/lists.h>
  14
  15 DECLARE_GLOBAL_DATA_PTR;
  16
  17 struct led_gpio_priv {
  18         struct gpio_desc gpio;
  19 };
  20
  21 static int gpio_led_set_on(struct udevice *dev, int on)
  22 {
  23         struct led_gpio_priv *priv = dev_get_priv(dev);
  24
  25         if (!dm_gpio_is_valid(&priv->gpio))
  26                 return -EREMOTEIO;
  27
  28         return dm_gpio_set_value(&priv->gpio, on);
  29 }
  30
  31 static int led_gpio_probe(struct udevice *dev)
  32 {
  33         struct led_uclass_plat *uc_plat = dev_get_uclass_platdata(dev);
  34         struct led_gpio_priv *priv = dev_get_priv(dev);
  35
  36         /* Ignore the top-level LED node */
  37         if (!uc_plat->label)
  38                 return 0;
  39         return gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
  40 }
  41
  42 static int led_gpio_remove(struct udevice *dev)
  43 {
  44         /*
  45          * The GPIO driver may have already been removed. We will need to
  46          * address this more generally.
  47          */
  48 #ifndef CONFIG_SANDBOX
  49         struct led_gpio_priv *priv = dev_get_priv(dev);
  50
  51         if (dm_gpio_is_valid(&priv->gpio))
  52                 dm_gpio_free(dev, &priv->gpio);
  53 #endif
  54
  55         return 0;
  56 }
  57
  58 static int led_gpio_bind(struct udevice *parent)
  59 {
  60         const void *blob = gd->fdt_blob;
  61         struct udevice *dev;
  62         int node;
  63         int ret;
  64
  65         for (node = fdt_first_subnode(blob, parent->of_offset);
  66              node > 0;
  67              node = fdt_next_subnode(blob, node)) {
  68                 struct led_uclass_plat *uc_plat;
  69                 const char *label;
  70
  71                 label = fdt_getprop(blob, node, "label", NULL);
  72                 if (!label) {
  73                         debug("%s: node %s has no label\n", __func__,
  74                               fdt_get_name(blob, node, NULL));
  75                         return -EINVAL;
  76                 }
  77                 ret = device_bind_driver_to_node(parent, "gpio_led",
  78                                                  fdt_get_name(blob, node, NULL),
  79                                                  node, &dev);
  80                 if (ret)
  81                         return ret;
  82                 uc_plat = dev_get_uclass_platdata(dev);
  83                 uc_plat->label = label;
  84         }
  85
  86         return 0;
  87 }
  88
  89 static const struct led_ops gpio_led_ops = {
  90         .set_on         = gpio_led_set_on,
  91 };
  92
  93 static const struct udevice_id led_gpio_ids[] = {
  94         { .compatible = "gpio-leds" },
  95         { }
  96 };
  97
  98 U_BOOT_DRIVER(led_gpio) = {
  99         .name   = "gpio_led",
 100         .id     = UCLASS_LED,
 101         .of_match = led_gpio_ids,
 102         .ops    = &gpio_led_ops,
 103         .priv_auto_alloc_size = sizeof(struct led_gpio_priv),
 104         .bind   = led_gpio_bind,
 105         .probe  = led_gpio_probe,
 106         .remove = led_gpio_remove,
 107 };