tda19988: driver for the TDA19988 HDMI Transmitter

Change-Id: Ia7750df3dd4ec4bd68624c800a0241c70eea7ca4

distrib/sets/lists/minix/md.evbarm

@@ -109,5 +109,6 @@
 ./usr/sbin/gpio				minix-sys
 ./usr/sbin/i2c				minix-sys
 ./usr/sbin/random			minix-sys
+./usr/sbin/tda19988			minix-sys
 ./usr/tests/minix-posix/mod		minix-sys
 ./usr/tests/minix-posix/test63		minix-sys

drivers/Makefile

@@ -23,7 +23,7 @@ SUBDIR= ahci amddev atl2 at_wini audio dec21140A dp8390 dpeth \
 .endif
 
 .if ${MACHINE_ARCH} == "earm"
-SUBDIR=  cat24c256 fb gpio i2c mmc log tty random
+SUBDIR=  cat24c256 fb gpio i2c mmc log tda19988 tty random
 .endif
 
 .endif # ${MKIMAGEONLY} != "yes"

drivers/tda19988/Makefile

@@ -0,0 +1,14 @@
+# Makefile for the tda19988 HDMI framer found on the BeagleBone Black.
+PROG=	tda19988
+SRCS=	tda19988.c
+
+DPADD+=	${LIBI2CDRIVER} ${LIBBLOCKDRIVER} ${LIBSYS} ${LIBTIMERS}
+LDADD+=	-li2cdriver -lblockdriver -lsys -ltimers
+
+MAN=
+
+BINDIR?= /usr/sbin
+
+CPPFLAGS+=	-I${NETBSDSRCDIR}
+
+.include <minix.service.mk>

drivers/tda19988/README.txt

@@ -0,0 +1,79 @@
+TDA19988 Driver (HDMI Framer)
+=============================
+
+Overview
+--------
+
+This is the driver for the HDMI Framer chip commonly found on the BeagleBone
+Black.
+
+Interface
+---------
+
+To make things easy for the frame buffer driver, a block device driver
+interface is provided. Read requests cause the TDA19988 driver to read
+the EDID and return the data.
+
+Documentation
+-------------
+
+The documentation available is rather thin. NXP doesn't provide a
+datasheet on their website and they did not respond to my request
+for a datasheet. There are a few other sources of information:
+
+ * TDA9983B.pdf - this chip is similar but not the same. Full
+ register descriptions are provided. This was suggested to me by
+ the author of the Linux driver and someone at BeagleBoard.org as
+ neither of them were able to get a full datasheet for the TDA19988.
+
+ * TDA19988.pdf - you can probably find this on the net. It's a
+ pre-production draft of the datasheet for the TDA19988. It has
+ some information about how things work, but it doesn't give details
+ on the registers.
+
+ * LPC4350_FPU_TFT_HDMI-v2.0/Driver/tda19988.c - there's some
+ example code from NXP for a Hitex LPC4350 REV A5 which includes
+ a BSD licensed driver from NXP. It isn't complete as it only does
+ test mode, put-through mode, and EDID reading. Some of the comments
+ in the code make it seem like it isn't totally working/tested.
+
+ * linux/drivers/gpu/drm/i2c/tda998x_drv.c - there is a Linux driver
+ which implements a lot of functionality. As is always the case,
+ great care has to be taken to only study the code to learn the
+ functionality of the chip and not reproduce/copy the code.
+
+Limitations
+-----------
+
+Currently, only the EDID reading functionality is implemented.
+
+Testing the Code
+----------------
+
+Starting up an instance:
+
+/bin/service up /usr/sbin/tda19988 -label tda19988.1.3470 \
+	-args 'cec_bus=1 cec_address=0x34 hdmi_bus=1 hdmi_address=0x70'
+
+Killing an instance:
+
+/bin/service down tda19988.1.3470
+
+The driver is meant to be accessed from other drivers using the block
+device protocol, so it doesn't have a reserved major number and device file.
+However, if you want a simple test from user space, you can create a temporary
+device file to read the EDID like this:
+
+cd /dev
+mknod tda19988 b 32 0
+chmod 600 tda19988
+/bin/service up /usr/sbin/tda19988 -label tda19988.1.3470 \
+	-dev /dev/tda19988 \
+	-args 'cec_bus=1 cec_address=0x34 hdmi_bus=1 hdmi_address=0x70'
+dd if=/dev/tda19988 of=/root/edid.dat count=1 bs=128
+/bin/service down tda19988.1.3470
+hexdump -C /root/edid.dat
+rm tda19988
+
+The hexdump should begin with the EDID magic number: 00 ff ff ff ff ff ff 00
+

etc/system.conf

@@ -568,7 +568,7 @@ service fb
 		PRIVCTL		#  4
         ;
 	ipc
-                SYSTEM pm rs ds vm vfs
+                SYSTEM pm rs ds vm vfs tda19988
 	;
 };
 
@@ -613,6 +613,11 @@ service cat24c256
 	ipc SYSTEM RS DS i2c;
 };
 
+service tda19988
+{
+	ipc SYSTEM RS DS i2c;
+};
+
 service vbox
 {
 	system

etc/usr/rc

@@ -210,6 +210,10 @@ start)
 			test -e /dev/eepromb1s50 || (cd /dev && MAKEDEV eepromb1s50)
 			up cat24c256 -dev /dev/eepromb1s50 \
 				-label cat24c256.1.50 -args 'bus=1 address=0x50'
+
+			# Start TDA19988 driver for EDID reading.
+			up tda19988 -label tda19988.1.3470 -args \
+				'cec_bus=1 cec_address=0x34 hdmi_bus=1 hdmi_address=0x70'
 			;;
 		UNKNOWN)
 			echo "Unable to detect board -- assuming BeagleBoard-xM"