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 const void *blob = gd->fdt_blob; 89 struct udevice *dev; 90 int node; 91 int ret; 92 93 for (node = fdt_first_subnode(blob, dev_of_offset(parent)); 94 node > 0; 95 node = fdt_next_subnode(blob, node)) { 96 struct led_uc_plat *uc_plat; 97 const char *label; 98 99 label = fdt_getprop(blob, node, "label", NULL); 100 if (!label) { 101 debug("%s: node %s has no label\n", __func__, 102 fdt_get_name(blob, node, NULL)); 103 return -EINVAL; 104 } 105 ret = device_bind_driver_to_node(parent, "gpio_led", 106 fdt_get_name(blob, node, NULL), 107 node, &dev); 108 if (ret) 109 return ret; 110 uc_plat = dev_get_uclass_platdata(dev); 111 uc_plat->label = label; 112 } 113 114 return 0; 115 } 116 117 static const struct led_ops gpio_led_ops = { 118 .set_state = gpio_led_set_state, 119 .get_state = gpio_led_get_state, 120 }; 121 122 static const struct udevice_id led_gpio_ids[] = { 123 { .compatible = "gpio-leds" }, 124 { } 125 }; 126 127 U_BOOT_DRIVER(led_gpio) = { 128 .name = "gpio_led", 129 .id = UCLASS_LED, 130 .of_match = led_gpio_ids, 131 .ops = &gpio_led_ops, 132 .priv_auto_alloc_size = sizeof(struct led_gpio_priv), 133 .bind = led_gpio_bind, 134 .probe = led_gpio_probe, 135 .remove = led_gpio_remove, 136 }; 137