AudioServer: Add support for volume control

userspace/libraries/LibAudio/Audio.cpp

@@ -145,7 +145,7 @@ namespace LibAudio
 
 		LibAudio::Packet packet {
 			.type = LibAudio::Packet::Notify,
-			.parameter = 0,
+			.parameter = {},
 		};
 
 		send(m_server_fd, &packet, sizeof(packet), 0);

userspace/libraries/LibAudio/include/LibAudio/Protocol.h

@@ -40,6 +40,14 @@ namespace LibAudio
 			SetPin,         // parameter: pin number
 			                // response: nothing
 							// set the active pin of the current device
+
+			GetVolume,      // parameter: ignored
+			                // response: 10 * volume percentage (uint32_t)
+							// get the volume of the current device
+
+			SetVolume,      // parameter: 10 * volume percentage (uint32_t)
+			                // response: nothing
+							// set the volume of the current device
 		} type;
 
 		uint64_t parameter;

userspace/programs/AudioServer/AudioServer.cpp

@@ -98,12 +98,53 @@ bool AudioServer::on_client_packet(int fd, LibAudio::Packet packet)
 				return false;
 			}
 			reset_kernel_buffer();
-			if (uint32_t pin = packet.parameter; ioctl(device().fd, SND_SET_PIN, &pin) != 0)
+			if (ioctl(device().fd, SND_SET_PIN, &packet.parameter) != 0)
 				dwarnln("Failed to set pin {}: {}", packet.parameter, strerror(errno));
 			else
+			{
 				device().current_pin = packet.parameter;
+
+				// NOTE: different pins have different volume controls
+				if (ioctl(device().fd, SND_GET_VOLUME_INFO, &device().volume) != 0)
+					dwarnln("Failed to query new volume: {}", strerror(errno));
+			}
 			update();
 			break;
+		case LibAudio::Packet::GetVolume:
+		{
+			// NOTE: maybe we should map [0->100%] -> [min, 0] instead?
+
+			const auto& volume = device().volume;
+			if (volume.min_mdB == volume.max_mdB)
+				response = 1000;
+			else
+			{
+				const double min_dB = volume.min_mdB / 1000.0;
+				const double max_dB = volume.max_mdB / 1000.0;
+				const double dB = volume.mdB / 1000.0;
+				const double percent = (BAN::Math::pow(10.0, (dB - min_dB) / (max_dB - min_dB)) - 1.0) / 9.0;
+				response = BAN::Math::round(percent * 1000.0);
+			}
+			break;
+		}
+		case LibAudio::Packet::SetVolume:
+		{
+			// NOTE: maybe we should map [0->100%] -> [min, 0] instead?
+
+			const auto& volume = device().volume;
+			const double min_dB = volume.min_mdB / 1000.0;
+			const double max_dB = volume.max_mdB / 1000.0;
+			const double percent = packet.parameter / 1000.0;
+			const double dB = min_dB + (max_dB - min_dB) * BAN::Math::log10(1.0 + 9.0 * percent);
+
+			const int32_t mdB = BAN::Math::round(dB * 1000.0);
+			if (ioctl(device().fd, SND_SET_VOLUME_MDB, &mdB) != 0)
+				dwarnln("Failed to set volume: {}", strerror(errno));
+			else if (ioctl(device().fd, SND_GET_VOLUME_INFO, &device().volume) != 0)
+				dwarnln("Failed to query new volume: {}", strerror(errno));
+
+			break;
+		}
 		default:
 			dwarnln("unknown packet type {}", static_cast<uint8_t>(packet.type));
 			return false;
@@ -278,7 +319,7 @@ void AudioServer::send_samples()
 			for (size_t i = 0; i < samples_to_send; i++)
 			{
 				sample_buffer[i] = BAN::Math::clamp<sample_t>(
-					0.2 * m_samples[m_samples_sent + i] * BAN::numeric_limits<kernel_sample_t>::max(),
+					m_samples[m_samples_sent + i] * BAN::numeric_limits<kernel_sample_t>::max(),
 					BAN::numeric_limits<kernel_sample_t>::min(),
 					BAN::numeric_limits<kernel_sample_t>::max()
 				);

userspace/programs/AudioServer/AudioServer.h

@@ -8,6 +8,8 @@
 #include <LibAudio/Audio.h>
 #include <LibAudio/Protocol.h>
 
+#include <sys/ioctl.h>
+
 struct AudioDevice
 {
 	int fd;
@@ -15,6 +17,7 @@ struct AudioDevice
 	uint32_t sample_rate;
 	uint32_t total_pins;
 	uint32_t current_pin;
+	snd_volume_info volume;
 };
 
 class AudioServer

userspace/programs/AudioServer/main.cpp

@@ -68,6 +68,8 @@ static BAN::Optional<AudioDevice> initialize_audio_device(int fd)
 		return {};
 	if (ioctl(fd, SND_GET_PIN, &result.current_pin) != 0)
 		return {};
+	if (ioctl(fd, SND_GET_VOLUME_INFO, &result.volume) != 0)
+		return {};
 	return result;
 }
 

userspace/programs/audioctl/main.cpp

@@ -74,17 +74,20 @@ static uint32_t send_request(int fd, LibAudio::Packet packet, bool wait_response
 
 static void list_devices(int fd)
 {
-	const uint32_t current_device = send_request(fd, { .type = LibAudio::Packet::GetDevice,    .parameter = 0 }, true);
+	const uint32_t current_device = send_request(fd, { .type = LibAudio::Packet::GetDevice,    .parameter = {} }, true);
-	const uint32_t current_pin    = send_request(fd, { .type = LibAudio::Packet::GetPin,       .parameter = 0 }, true);
+	const uint32_t current_pin    = send_request(fd, { .type = LibAudio::Packet::GetPin,       .parameter = {} }, true);
 
-	const uint32_t total_devices  = send_request(fd, { .type = LibAudio::Packet::QueryDevices, .parameter = 0 }, true);
+	const uint32_t total_devices  = send_request(fd, { .type = LibAudio::Packet::QueryDevices, .parameter = {} }, true);
 	for (uint32_t dev = 0; dev < total_devices; dev++)
 	{
 		const uint32_t total_pins = send_request(fd, { .type = LibAudio::Packet::QueryPins, .parameter = dev }, true);
 
 		printf("Device %" PRIu32 "", dev);
 		if (dev == current_device)
-			printf(" (current)");
+		{
+			const uint32_t volume = send_request(fd, { .type = LibAudio::Packet::GetVolume, .parameter = {} }, true);
+			printf(" (current) %" PRIu32 "%%", volume / 10);
+		}
 		printf("\n");
 
 		for (uint32_t pin = 0; pin < total_pins; pin++)
@@ -103,16 +106,20 @@ int main(int argc, char** argv)
 	BAN::Optional<uint32_t> device;
 	BAN::Optional<uint32_t> pin;
 
+	BAN::Optional<uint32_t> volume;
+	BAN::Optional<bool> volume_rel; // no value: absolute, false positive, true negative
+
 	for (;;)
 	{
 		static option long_options[] {
 			{ "list",   no_argument,       nullptr, 'l' },
 			{ "device", required_argument, nullptr, 'd' },
 			{ "pin",    required_argument, nullptr, 'p' },
+			{ "volume", required_argument, nullptr, 'v' },
 			{ "help",   no_argument,       nullptr, 'h' },
 		};
 
-		int ch = getopt_long(argc, argv, "ld:p:h", long_options, nullptr);
+		int ch = getopt_long(argc, argv, "ld:p:v:h", long_options, nullptr);
 		if (ch == -1)
 			break;
 
@@ -125,6 +132,7 @@ int main(int argc, char** argv)
 				fprintf(stderr, "  -l, --list      list devices and their pins\n");
 				fprintf(stderr, "  -d, --device N  set device index N as the current one\n");
 				fprintf(stderr, "  -p, --pin N     set pin N as the current one\n");
+				fprintf(stderr, "  -v, --volume N  set volume to N%%. if + or - is given, volume is relative to the current volume\n");
 				fprintf(stderr, "  -h, --help      show this message and exit\n");
 				return 0;
 			case 'l':
@@ -136,6 +144,11 @@ int main(int argc, char** argv)
 			case 'p':
 				pin = parse_u32_or_exit(optarg);
 				break;
+			case 'v':
+				if (optarg[0] == '-' || optarg[0] == '+')
+					volume_rel = (optarg[0] == '-');
+				volume = parse_u32_or_exit(optarg + volume_rel.has_value());
+				break;
 			case '?':
 				fprintf(stderr, "invalid option %c\n", optopt);
 				fprintf(stderr, "see '%s --help' for usage\n", argv[0]);
@@ -143,7 +156,7 @@ int main(int argc, char** argv)
 		}
 	}
 
-	if (!device.has_value() && !pin.has_value())
+	if (!device.has_value() && !pin.has_value() && !volume.has_value())
 		list = true;
 
 	const int fd = get_server_fd();
@@ -156,6 +169,30 @@ int main(int argc, char** argv)
 	if (pin.has_value())
 		send_request(fd, { .type = LibAudio::Packet::SetPin, .parameter = pin.value() }, false);
 
+	if (volume.has_value())
+	{
+		const uint32_t volume10 = volume.value() * 10;
+
+		uint32_t param;
+		if (!volume_rel.has_value())
+			param = volume10;
+		else
+		{
+			const uint32_t current = send_request(fd, { .type = LibAudio::Packet::GetVolume, .parameter = {} }, true);
+			if (!volume_rel.value())
+				param = current + volume10;
+			else
+			{
+				if (current > volume10)
+					param = current - volume10;
+				else
+					param = 0;
+			}
+		}
+
+		send_request(fd, { .type = LibAudio::Packet::SetVolume, .parameter = param }, false);
+	}
+
 	if (list)
 		list_devices(fd);