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Commit 446091c9 authored by Jacopo Mondi's avatar Jacopo Mondi Committed by Greg Kroah-Hartman
Browse files

greybus: camera: Add CSI configuration parameters 



Add CSI configuration parameters to the configure_stream operation
response.
Currently, only the total number of lines in a second is used to configure the
the AP-Bridge CSI transmitter, all other parameters (number of CSI data
lanes, and CSI bus clock frequency) are kept hard-coded for two reasons:
1) We need to configure the CSI receiver on AP side accordingly to these
settings, before sending them to APB1 CSI transmitter.
2) We cannot use the camera module provided parameters as-is, but use
those information to compute the required bandwidth on the CSI bus, and
configure the # of CSI data lanes, and the CSI bus clock speed in a way that
satisfies that bandwidth requirement.

Signed-off-by: default avatarJacopo Mondi <jacopo.mondi@linaro.org>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@google.com>
parent 7f29aded

drivers/staging/greybus/camera.c

+10 −1
Original line number Diff line number Diff line
@@ -162,6 +162,7 @@ struct ap_csi_config_request { 
	__u8 num_lanes;

	__u8 padding;

	__le32 bus_freq;

	__le32 lines_per_second;

} __packed;



static int gb_camera_configure_streams(struct gb_camera *gcam,
@@ -254,7 +255,14 @@ static int gb_camera_configure_streams(struct gb_camera *gcam, 
	if (ret < 0)

		goto done;



	/* Configure the CSI transmitter. Hardcode the parameters for now. */

	/*

	 * Configure the APB1 CSI transmitter using the lines count reported by

	 * the  camera module, but with hard-coded bus frequency and lanes number.

	 *

	 * TODO: use the clocking and size informations reported by camera module

	 * to compute the required CSI bandwidth, and configure the CSI receiver

	 * on AP side, and the CSI transmitter on APB1 side accordingly.

	 */

	memset(&csi_cfg, 0, sizeof(csi_cfg));



	if (nstreams) {
@@ -262,6 +270,7 @@ static int gb_camera_configure_streams(struct gb_camera *gcam, 
		csi_cfg.clock_mode = 0;

		csi_cfg.num_lanes = 4;

		csi_cfg.bus_freq = cpu_to_le32(960000000);

		csi_cfg.lines_per_second = resp->lines_per_second;

		ret = gb_hd_output(gcam->connection->hd, &csi_cfg,

				   sizeof(csi_cfg),

				   GB_APB_REQUEST_CSI_TX_CONTROL, false);

drivers/staging/greybus/greybus_protocols.h

+4 −1
Original line number Diff line number Diff line
@@ -1276,7 +1276,10 @@ struct gb_camera_configure_streams_response { 
	__u8 num_streams;

	__u8 flags;

#define GB_CAMERA_CONFIGURE_STREAMS_ADJUSTED	0x01

	__le16 padding;

	__u8 num_lanes;

	__u8 padding;

	__le32 bus_freq;

	__le32 lines_per_second;

	struct gb_camera_stream_config_response config[0];

} __packed;