greybus: audio: Add direct audio streaming control for APBridgeA

The latest audio architecture does not stream audio data over the
USB link between the AP and APBridgeA.  Instead, audio data is
streamed directly over the I2S link between the two.

To support the Greybus audio driver in setting up the I2S port and
controling packeting/depacketizing of audio data to/from Greybus
audio messages, define a set of commands and their parameters.
These commands and parameters will be placed into a request and sent
over the USB control channel to APBridgeA.  A corresponding driver
on APBridgeA will receive and process the requests.

Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

1 files changed, 156 insertions, 0 deletions

diff --git a/drivers/staging/greybus/audio_apbridgea.c b/drivers/staging/greybus/audio_apbridgea.c
new file mode 100644
index 000000000000..20238e68e83a
--- /dev/null
+++ b/drivers/staging/greybus/audio_apbridgea.c
@@ -0,0 +1,156 @@
+/*
+ * Greybus Audio Device Class Protocol helpers
+ *
+ * Copyright 2015-2016 Google Inc.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include "greybus.h"
+#include "greybus_protocols.h"
+#include "audio_apbridgea.h"
+
+int gb_audio_apbridgea_set_config(struct gb_connection *connection,
+				  __u16 i2s_port, __u32 format, __u32 rate,
+				  __u32 mclk_freq)
+{
+	struct audio_apbridgea_set_config_request req;
+
+	req.hdr.type = AUDIO_APBRIDGEA_TYPE_SET_CONFIG;
+	req.hdr.i2s_port = cpu_to_le16(i2s_port);
+	req.format = cpu_to_le32(format);
+	req.rate = cpu_to_le32(rate);
+	req.mclk_freq = cpu_to_le32(mclk_freq);
+
+	return gb_hd_output(connection->hd, &req, sizeof(req),
+			    GB_APB_REQUEST_AUDIO_CONTROL, true);
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_set_config);
+
+int gb_audio_apbridgea_register_cport(struct gb_connection *connection,
+				      __u16 i2s_port, __u16 cportid)
+{
+	struct audio_apbridgea_register_cport_request req;
+
+	req.hdr.type = AUDIO_APBRIDGEA_TYPE_REGISTER_CPORT;
+	req.hdr.i2s_port = cpu_to_le16(i2s_port);
+	req.cport = cpu_to_le16(cportid);
+
+	return gb_hd_output(connection->hd, &req, sizeof(req),
+			    GB_APB_REQUEST_AUDIO_CONTROL, true);
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_register_cport);
+
+int gb_audio_apbridgea_unregister_cport(struct gb_connection *connection,
+					__u16 i2s_port, __u16 cportid)
+{
+	struct audio_apbridgea_unregister_cport_request req;
+
+	req.hdr.type = AUDIO_APBRIDGEA_TYPE_UNREGISTER_CPORT;
+	req.hdr.i2s_port = cpu_to_le16(i2s_port);
+	req.cport = cpu_to_le16(cportid);
+
+	return gb_hd_output(connection->hd, &req, sizeof(req),
+			    GB_APB_REQUEST_AUDIO_CONTROL, true);
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_unregister_cport);
+
+int gb_audio_apbridgea_set_tx_data_size(struct gb_connection *connection,
+					__u16 i2s_port, __u16 size)
+{
+	struct audio_apbridgea_set_tx_data_size_request req;
+
+	req.hdr.type = AUDIO_APBRIDGEA_TYPE_SET_TX_DATA_SIZE;
+	req.hdr.i2s_port = cpu_to_le16(i2s_port);
+	req.size = cpu_to_le16(size);
+
+	return gb_hd_output(connection->hd, &req, sizeof(req),
+			    GB_APB_REQUEST_AUDIO_CONTROL, true);
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_set_tx_data_size);
+
+int gb_audio_apbridgea_get_tx_delay(struct gb_connection *connection,
+				    __u16 i2s_port, __u32 *delay)
+{
+	/* TODO: implement */
+	return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_get_tx_delay);
+
+int gb_audio_apbridgea_start_tx(struct gb_connection *connection,
+				__u16 i2s_port, __u64 timestamp)
+{
+	struct audio_apbridgea_start_tx_request req;
+
+	req.hdr.type = AUDIO_APBRIDGEA_TYPE_START_TX;
+	req.hdr.i2s_port = cpu_to_le16(i2s_port);
+	req.timestamp = cpu_to_le64(timestamp);
+
+	return gb_hd_output(connection->hd, &req, sizeof(req),
+			    GB_APB_REQUEST_AUDIO_CONTROL, true);
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_start_tx);
+
+int gb_audio_apbridgea_stop_tx(struct gb_connection *connection, __u16 i2s_port)
+{
+	struct audio_apbridgea_stop_tx_request req;
+
+	req.hdr.type = AUDIO_APBRIDGEA_TYPE_STOP_TX;
+	req.hdr.i2s_port = cpu_to_le16(i2s_port);
+
+	return gb_hd_output(connection->hd, &req, sizeof(req),
+			    GB_APB_REQUEST_AUDIO_CONTROL, true);
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_stop_tx);
+
+int gb_audio_apbridgea_set_rx_data_size(struct gb_connection *connection,
+					__u16 i2s_port, __u16 size)
+{
+	struct audio_apbridgea_set_rx_data_size_request req;
+
+	req.hdr.type = AUDIO_APBRIDGEA_TYPE_SET_RX_DATA_SIZE;
+	req.hdr.i2s_port = cpu_to_le16(i2s_port);
+	req.size = cpu_to_le16(size);
+
+	return gb_hd_output(connection->hd, &req, sizeof(req),
+			    GB_APB_REQUEST_AUDIO_CONTROL, true);
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_set_rx_data_size);
+
+int gb_audio_apbridgea_get_rx_delay(struct gb_connection *connection,
+				    __u16 i2s_port, __u32 *delay)
+{
+	/* TODO: implement */
+	return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_get_rx_delay);
+
+int gb_audio_apbridgea_start_rx(struct gb_connection *connection,
+				__u16 i2s_port)
+{
+	struct audio_apbridgea_start_rx_request req;
+
+	req.hdr.type = AUDIO_APBRIDGEA_TYPE_START_RX;
+	req.hdr.i2s_port = cpu_to_le16(i2s_port);
+
+	return gb_hd_output(connection->hd, &req, sizeof(req),
+			    GB_APB_REQUEST_AUDIO_CONTROL, true);
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_start_rx);
+
+int gb_audio_apbridgea_stop_rx(struct gb_connection *connection, __u16 i2s_port)
+{
+	struct audio_apbridgea_stop_rx_request req;
+
+	req.hdr.type = AUDIO_APBRIDGEA_TYPE_STOP_RX;
+	req.hdr.i2s_port = cpu_to_le16(i2s_port);
+
+	return gb_hd_output(connection->hd, &req, sizeof(req),
+			    GB_APB_REQUEST_AUDIO_CONTROL, true);
+}
+EXPORT_SYMBOL_GPL(gb_audio_apbridgea_stop_rx);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("greybus:audio-apbridgea");
+MODULE_DESCRIPTION("Greybus Special APBridgeA Audio Protocol library");
+MODULE_AUTHOR("Mark Greer <mgreer@animalcreek.com>");