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_state(struct udevice *dev, enum led_state_t state)
  22 {
  23         struct led_gpio_priv *priv = dev_get_priv(dev);
  24
  25         if (!dm_gpio_is_valid(&priv->gpio))
  26                 return -EREMOTEIO;
  27         switch (state) {
  28         case LEDST_OFF:
  29         case LEDST_ON:
  30                 break;
  31         default:
  32                 return -ENOSYS;
  33         }
  34
  35         return dm_gpio_set_value(&priv->gpio, state);
  36 }
  37
  38 static enum led_state_t gpio_led_get_state(struct udevice *dev)
  39 {
  40         struct led_gpio_priv *priv = dev_get_priv(dev);
  41         int ret;
  42
  43         if (!dm_gpio_is_valid(&priv->gpio))
  44                 return -EREMOTEIO;
  45         ret = dm_gpio_get_value(&priv->gpio);
  46         if (ret < 0)
  47                 return ret;
  48
  49         return ret ? LEDST_ON : LEDST_OFF;
  50 }
  51
  52 static int led_gpio_probe(struct udevice *dev)
  53 {
  54         struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
  55         struct led_gpio_priv *priv = dev_get_priv(dev);
  56
  57         /* Ignore the top-level LED node */
  58         if (!uc_plat->label)
  59                 return 0;
  60         return gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
  61 }
  62
  63 static int led_gpio_remove(struct udevice *dev)
  64 {
  65         /*
  66          * The GPIO driver may have already been removed. We will need to
  67          * address this more generally.
  68          */
  69 #ifndef CONFIG_SANDBOX
  70         struct led_gpio_priv *priv = dev_get_priv(dev);
  71
  72         if (dm_gpio_is_valid(&priv->gpio))
  73                 dm_gpio_free(dev, &priv->gpio);
  74 #endif
  75
  76         return 0;
  77 }
  78
  79 static int led_gpio_bind(struct udevice *parent)
  80 {
  81         const void *blob = gd->fdt_blob;
  82         struct udevice *dev;
  83         int node;
  84         int ret;
  85
  86         for (node = fdt_first_subnode(blob, dev_of_offset(parent));
  87              node > 0;
  88              node = fdt_next_subnode(blob, node)) {
  89                 struct led_uc_plat *uc_plat;
  90                 const char *label;
  91
  92                 label = fdt_getprop(blob, node, "label", NULL);
  93                 if (!label) {
  94                         debug("%s: node %s has no label\n", __func__,
  95                               fdt_get_name(blob, node, NULL));
  96                         return -EINVAL;
  97                 }
  98                 ret = device_bind_driver_to_node(parent, "gpio_led",
  99                                                  fdt_get_name(blob, node, NULL),
 100                                                  node, &dev);
 101                 if (ret)
 102                         return ret;
 103                 uc_plat = dev_get_uclass_platdata(dev);
 104                 uc_plat->label = label;
 105         }
 106
 107         return 0;
 108 }
 109
 110 static const struct led_ops gpio_led_ops = {
 111         .set_state      = gpio_led_set_state,
 112         .get_state      = gpio_led_get_state,
 113 };
 114
 115 static const struct udevice_id led_gpio_ids[] = {
 116         { .compatible = "gpio-leds" },
 117         { }
 118 };
 119
 120 U_BOOT_DRIVER(led_gpio) = {
 121         .name   = "gpio_led",
 122         .id     = UCLASS_LED,
 123         .of_match = led_gpio_ids,
 124         .ops    = &gpio_led_ops,
 125         .priv_auto_alloc_size = sizeof(struct led_gpio_priv),
 126         .bind   = led_gpio_bind,
 127         .probe  = led_gpio_probe,
 128         .remove = led_gpio_remove,
 129 };