1 /* 2 * QEMU single LED device 3 * 4 * Copyright (C) 2020 Philippe Mathieu-Daudé <f4bug@amsat.org> 5 * 6 * SPDX-License-Identifier: GPL-2.0-or-later 7 */ 8 #include "qemu/osdep.h" 9 #include "qapi/error.h" 10 #include "migration/vmstate.h" 11 #include "hw/qdev-properties.h" 12 #include "hw/misc/led.h" 13 #include "hw/irq.h" 14 #include "trace.h" 15 16 #define LED_INTENSITY_PERCENT_MAX 100 17 18 static const char * const led_color_name[] = { 19 [LED_COLOR_VIOLET] = "violet", 20 [LED_COLOR_BLUE] = "blue", 21 [LED_COLOR_CYAN] = "cyan", 22 [LED_COLOR_GREEN] = "green", 23 [LED_COLOR_YELLOW] = "yellow", 24 [LED_COLOR_AMBER] = "amber", 25 [LED_COLOR_ORANGE] = "orange", 26 [LED_COLOR_RED] = "red", 27 }; 28 29 static bool led_color_name_is_valid(const char *color_name) 30 { 31 for (size_t i = 0; i < ARRAY_SIZE(led_color_name); i++) { 32 if (strcmp(color_name, led_color_name[i]) == 0) { 33 return true; 34 } 35 } 36 return false; 37 } 38 39 void led_set_intensity(LEDState *s, unsigned intensity_percent) 40 { 41 if (intensity_percent > LED_INTENSITY_PERCENT_MAX) { 42 intensity_percent = LED_INTENSITY_PERCENT_MAX; 43 } 44 trace_led_set_intensity(s->description, s->color, intensity_percent); 45 if (intensity_percent != s->intensity_percent) { 46 trace_led_change_intensity(s->description, s->color, 47 s->intensity_percent, intensity_percent); 48 } 49 s->intensity_percent = intensity_percent; 50 } 51 52 unsigned led_get_intensity(LEDState *s) 53 { 54 return s->intensity_percent; 55 } 56 57 void led_set_state(LEDState *s, bool is_emitting) 58 { 59 led_set_intensity(s, is_emitting ? LED_INTENSITY_PERCENT_MAX : 0); 60 } 61 62 static void led_set_state_gpio_handler(void *opaque, int line, int new_state) 63 { 64 LEDState *s = LED(opaque); 65 66 assert(line == 0); 67 led_set_state(s, !!new_state != s->gpio_active_high); 68 } 69 70 static void led_reset(DeviceState *dev) 71 { 72 LEDState *s = LED(dev); 73 74 led_set_state(s, s->gpio_active_high); 75 } 76 77 static const VMStateDescription vmstate_led = { 78 .name = TYPE_LED, 79 .version_id = 1, 80 .minimum_version_id = 1, 81 .fields = (VMStateField[]) { 82 VMSTATE_UINT8(intensity_percent, LEDState), 83 VMSTATE_END_OF_LIST() 84 } 85 }; 86 87 static void led_realize(DeviceState *dev, Error **errp) 88 { 89 LEDState *s = LED(dev); 90 91 if (s->color == NULL) { 92 error_setg(errp, "property 'color' not specified"); 93 return; 94 } else if (!led_color_name_is_valid(s->color)) { 95 error_setg(errp, "property 'color' invalid or not supported"); 96 return; 97 } 98 if (s->description == NULL) { 99 s->description = g_strdup("n/a"); 100 } 101 102 qdev_init_gpio_in(DEVICE(s), led_set_state_gpio_handler, 1); 103 } 104 105 static Property led_properties[] = { 106 DEFINE_PROP_STRING("color", LEDState, color), 107 DEFINE_PROP_STRING("description", LEDState, description), 108 DEFINE_PROP_BOOL("gpio-active-high", LEDState, gpio_active_high, true), 109 DEFINE_PROP_END_OF_LIST(), 110 }; 111 112 static void led_class_init(ObjectClass *klass, void *data) 113 { 114 DeviceClass *dc = DEVICE_CLASS(klass); 115 116 dc->desc = "LED"; 117 dc->vmsd = &vmstate_led; 118 dc->reset = led_reset; 119 dc->realize = led_realize; 120 set_bit(DEVICE_CATEGORY_DISPLAY, dc->categories); 121 device_class_set_props(dc, led_properties); 122 } 123 124 static const TypeInfo led_info = { 125 .name = TYPE_LED, 126 .parent = TYPE_DEVICE, 127 .instance_size = sizeof(LEDState), 128 .class_init = led_class_init 129 }; 130 131 static void led_register_types(void) 132 { 133 type_register_static(&led_info); 134 } 135 136 type_init(led_register_types) 137 138 LEDState *led_create_simple(Object *parentobj, 139 GpioPolarity gpio_polarity, 140 LEDColor color, 141 const char *description) 142 { 143 g_autofree char *name = NULL; 144 DeviceState *dev; 145 146 dev = qdev_new(TYPE_LED); 147 qdev_prop_set_bit(dev, "gpio-active-high", 148 gpio_polarity == GPIO_POLARITY_ACTIVE_HIGH); 149 qdev_prop_set_string(dev, "color", led_color_name[color]); 150 if (!description) { 151 static unsigned undescribed_led_id; 152 name = g_strdup_printf("undescribed-led-#%u", undescribed_led_id++); 153 } else { 154 qdev_prop_set_string(dev, "description", description); 155 name = g_ascii_strdown(description, -1); 156 name = g_strdelimit(name, " #", '-'); 157 } 158 object_property_add_child(parentobj, name, OBJECT(dev)); 159 qdev_realize_and_unref(dev, NULL, &error_fatal); 160 161 return LED(dev); 162 } 163