summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c
AgeCommit message (Collapse)AuthorFilesLines
2018-03-01drm: omapdrm: hdmi4: Allocate the omap_hdmi data structure dynamicallyLaurent Pinchart1-2/+2
The omap_hdmi private data structure is currently stored as a global variable. While no platform with multiple HDMI4 encoders currently exists nor is planned, this doesn't comply with the kernel device model and should thus be fixed. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
2018-01-02omapdrm/dss/hdmi4_cec: fix interrupt handlingHans Verkuil1-37/+9
The omap4 CEC hardware cannot tell a Nack from a Low Drive from an Arbitration Lost error, so just report a Nack, which is almost certainly the reason for the error anyway. This also simplifies the implementation. The only three interrupts that need to be enabled are: Transmit Buffer Full/Empty Change event: triggered when the transmit finished successfully and cleared the buffer. Receiver FIFO Not Empty event: triggered when a message was received. Frame Retransmit Count Exceeded event: triggered when a transmit failed repeatedly, usually due to the message being Nacked. Other reasons are possible (Low Drive, Arbitration Lost) but there is no way to know. If this happens the TX buffer needs to be cleared manually. While testing various error conditions I noticed that the hardware can receive messages up to 18 bytes in total, which exceeds the legal maximum of 16. This could cause a buffer overflow, so we check for this and constrain the size to 16 bytes. The old incorrect interrupt handler could cause the CEC framework to enter into a bad state because it mis-detected the "Start Bit Irregularity event" as an ARB_LOST transmit error when it actually is a receive error which should be ignored. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reported-by: Henrik Austad <haustad@cisco.com> Tested-by: Henrik Austad <haustad@cisco.com> Tested-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2017-11-30omapdrm: hdmi4_cec: signedness bug in hdmi4_cec_init()Dan Carpenter1-1/+1
"ret" needs to be signed for the error handling to work. Fixes: 8d7f934df8d8 ("omapdrm: hdmi4_cec: add OMAP4 HDMI CEC support") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2017-10-12omapdrm: hdmi4_cec: add OMAP4 HDMI CEC supportHans Verkuil1-0/+381
Add the source and header for the OMAP4 HDMI CEC support. This code is not yet hooked up, that will happen in the next patch. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>