drivers/led/led-uclass.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2015 Google, Inc
   4  * Written by Simon Glass <sjg@chromium.org>
   5  */
   6
   7 #define LOG_CATEGORY UCLASS_LED
   8
   9 #include <common.h>
  10 #include <dm.h>
  11 #include <errno.h>
  12 #include <led.h>
  13 #include <dm/device-internal.h>
  14 #include <dm/root.h>
  15 #include <dm/uclass-internal.h>
  16
  17 int led_get_by_label(const char *label, struct udevice **devp)
  18 {
  19         struct udevice *dev;
  20         struct uclass *uc;
  21         int ret;
  22
  23         ret = uclass_get(UCLASS_LED, &uc);
  24         if (ret)
  25                 return ret;
  26         uclass_foreach_dev(dev, uc) {
  27                 struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
  28
  29                 /* Ignore the top-level LED node */
  30                 if (uc_plat->label && !strcmp(label, uc_plat->label))
  31                         return uclass_get_device_tail(dev, 0, devp);
  32         }
  33
  34         return -ENODEV;
  35 }
  36
  37 int led_set_state(struct udevice *dev, enum led_state_t state)
  38 {
  39         struct led_ops *ops = led_get_ops(dev);
  40
  41         if (!ops->set_state)
  42                 return -ENOSYS;
  43
  44         return ops->set_state(dev, state);
  45 }
  46
  47 enum led_state_t led_get_state(struct udevice *dev)
  48 {
  49         struct led_ops *ops = led_get_ops(dev);
  50
  51         if (!ops->get_state)
  52                 return -ENOSYS;
  53
  54         return ops->get_state(dev);
  55 }
  56
  57 #ifdef CONFIG_LED_BLINK
  58 int led_set_period(struct udevice *dev, int period_ms)
  59 {
  60         struct led_ops *ops = led_get_ops(dev);
  61
  62         if (!ops->set_period)
  63                 return -ENOSYS;
  64
  65         return ops->set_period(dev, period_ms);
  66 }
  67 #endif
  68
  69 /* This is superseded by led_post_bind()/led_post_probe() below. */
  70 int led_default_state(void)
  71 {
  72         return 0;
  73 }
  74
  75 static int led_post_bind(struct udevice *dev)
  76 {
  77         struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
  78         const char *default_state;
  79
  80         uc_plat->label = dev_read_string(dev, "label");
  81         if (!uc_plat->label)
  82                 uc_plat->label = ofnode_get_name(dev_ofnode(dev));
  83
  84         uc_plat->default_state = LEDST_COUNT;
  85
  86         default_state = dev_read_string(dev, "default-state");
  87         if (!default_state)
  88                 return 0;
  89
  90         if (!strncmp(default_state, "on", 2))
  91                 uc_plat->default_state = LEDST_ON;
  92         else if (!strncmp(default_state, "off", 3))
  93                 uc_plat->default_state = LEDST_OFF;
  94         else
  95                 return 0;
  96
  97         /*
  98          * In case the LED has default-state DT property, trigger
  99          * probe() to configure its default state during startup.
 100          */
 101         return device_probe(dev);
 102 }
 103
 104 static int led_post_probe(struct udevice *dev)
 105 {
 106         struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
 107
 108         if (uc_plat->default_state == LEDST_ON ||
 109             uc_plat->default_state == LEDST_OFF)
 110                 led_set_state(dev, uc_plat->default_state);
 111
 112         return 0;
 113 }
 114
 115 UCLASS_DRIVER(led) = {
 116         .id             = UCLASS_LED,
 117         .name           = "led",
 118         .per_device_plat_auto   = sizeof(struct led_uc_plat),
 119         .post_bind      = led_post_bind,
 120         .post_probe     = led_post_probe,
 121 };