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         int ret;
  25
  26         if (!dm_gpio_is_valid(&priv->gpio))
  27                 return -EREMOTEIO;
  28         switch (state) {
  29         case LEDST_OFF:
  30         case LEDST_ON:
  31                 break;
  32         case LEDST_TOGGLE:
  33                 ret = dm_gpio_get_value(&priv->gpio);
  34                 if (ret < 0)
  35                         return ret;
  36                 state = !ret;
  37                 break;
  38         default:
  39                 return -ENOSYS;
  40         }
  41
  42         return dm_gpio_set_value(&priv->gpio, state);
  43 }
  44
  45 static enum led_state_t gpio_led_get_state(struct udevice *dev)
  46 {
  47         struct led_gpio_priv *priv = dev_get_priv(dev);
  48         int ret;
  49
  50         if (!dm_gpio_is_valid(&priv->gpio))
  51                 return -EREMOTEIO;
  52         ret = dm_gpio_get_value(&priv->gpio);
  53         if (ret < 0)
  54                 return ret;
  55
  56         return ret ? LEDST_ON : LEDST_OFF;
  57 }
  58
  59 static int led_gpio_probe(struct udevice *dev)
  60 {
  61         struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
  62         struct led_gpio_priv *priv = dev_get_priv(dev);
  63
  64         /* Ignore the top-level LED node */
  65         if (!uc_plat->label)
  66                 return 0;
  67         return gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
  68 }
  69
  70 static int led_gpio_remove(struct udevice *dev)
  71 {
  72         /*
  73          * The GPIO driver may have already been removed. We will need to
  74          * address this more generally.
  75          */
  76 #ifndef CONFIG_SANDBOX
  77         struct led_gpio_priv *priv = dev_get_priv(dev);
  78
  79         if (dm_gpio_is_valid(&priv->gpio))
  80                 dm_gpio_free(dev, &priv->gpio);
  81 #endif
  82
  83         return 0;
  84 }
  85
  86 static int led_gpio_bind(struct udevice *parent)
  87 {
  88         struct udevice *dev;
  89         ofnode node;
  90         int ret;
  91
  92         dev_for_each_subnode(node, parent) {
  93                 struct led_uc_plat *uc_plat;
  94                 const char *label;
  95
  96                 label = ofnode_read_string(node, "label");
  97                 if (!label) {
  98                         debug("%s: node %s has no label\n", __func__,
  99                               ofnode_get_name(node));
 100                         return -EINVAL;
 101                 }
 102                 ret = device_bind_driver_to_node(parent, "gpio_led",
 103                                                  ofnode_get_name(node),
 104                                                  node, &dev);
 105                 if (ret)
 106                         return ret;
 107                 uc_plat = dev_get_uclass_platdata(dev);
 108                 uc_plat->label = label;
 109         }
 110
 111         return 0;
 112 }
 113
 114 static const struct led_ops gpio_led_ops = {
 115         .set_state      = gpio_led_set_state,
 116         .get_state      = gpio_led_get_state,
 117 };
 118
 119 static const struct udevice_id led_gpio_ids[] = {
 120         { .compatible = "gpio-leds" },
 121         { }
 122 };
 123
 124 U_BOOT_DRIVER(led_gpio) = {
 125         .name   = "gpio_led",
 126         .id     = UCLASS_LED,
 127         .of_match = led_gpio_ids,
 128         .ops    = &gpio_led_ops,
 129         .priv_auto_alloc_size = sizeof(struct led_gpio_priv),
 130         .bind   = led_gpio_bind,
 131         .probe  = led_gpio_probe,
 132         .remove = led_gpio_remove,
 133 };