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