drm/dsi: Add message to packet translator

This commit introduces a new function, mipi_dsi_create_packet(), which
converts from a MIPI DSI message to a MIPI DSI packet. The MIPI DSI
packet is as close to the protocol described in the DSI specification as
possible and useful in drivers that need to write a DSI packet into a
FIFO to send a message off to the peripheral.

Suggested-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index f1a07e3..6e3e3aa 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -47,6 +47,24 @@ bool mipi_dsi_packet_format_is_short(u8 type);
 bool mipi_dsi_packet_format_is_long(u8 type);
 
 /**
+ * struct mipi_dsi_packet - represents a MIPI DSI packet in protocol format
+ * @size: size (in bytes) of the packet
+ * @header: the four bytes that make up the header (Data ID, Word Count or
+ *     Packet Data, and ECC)
+ * @payload_length: number of bytes in the payload
+ * @payload: a pointer to a buffer containing the payload, if any
+ */
+struct mipi_dsi_packet {
+	size_t size;
+	u8 header[4];
+	size_t payload_length;
+	const u8 *payload;
+};
+
+int mipi_dsi_create_packet(struct mipi_dsi_packet *packet,
+			   const struct mipi_dsi_msg *msg);
+
+/**
  * struct mipi_dsi_host_ops - DSI bus operations
  * @attach: attach DSI device to DSI host
  * @detach: detach DSI device from DSI host