xref: /openbmc/u-boot/doc/README.bus_vcxk (revision a381bcf5)
1/*
2 * (C) Copyright 2008-2009
3 * BuS Elektronik GmbH & Co. KG <www.bus-elektronik.de>
4 * Jens Scharsig <esw@bus-elektronik.de>
5 *
6 * SPDX-License-Identifier:	GPL-2.0+
7 */
8
9U-Boot vcxk video controller driver
10======================================
11
12By defining CONFIG_VIDEO_VCXK this driver can be used with VC2K, VC4K and
13VC8K devices on following boards:
14
15board           | ARCH          | Vendor
16-----------------------------------------------------------------------
17EB+CPU5282-T1   | MCF5282       | BuS Elektronik GmbH & Co. KG
18EB+MCF-EVB123   | MCF5282       | BuS Elektronik GmbH & Co. KG
19EB+CPUx9K2      | AT91RM9200    | BuS Elektronik GmbH & Co. KG
20ZLSA            | AT91RM9200    | Ruf Telematik AG
21
22Driver configuration
23--------------------
24
25The driver needs some defines to describe the target hardware:
26
27CONFIG_SYS_VCXK_BASE
28
29	base address of VCxK hardware memory
30
31CONFIG_SYS_VCXK_DEFAULT_LINEALIGN
32
33	defines the physical alignment of a pixel row
34
35CONFIG_SYS_VCXK_DOUBLEBUFFERED
36
37	some boards that use vcxk prevent read from framebuffer memory.
38	define this option to enable double buffering (needs 16KiB RAM)
39
40CONFIG_SYS_VCXK_<xxxx>_PIN
41
42	defines the number of the I/O line PIN in the port
43	valid values for <xxxx> are:
44
45		ACKNOWLEDGE
46			describes the acknowledge line from vcxk hardware
47
48		ENABLE
49			describes the enable line to vcxk hardware
50
51		INVERT
52			describes the invert line to vcxk hardware
53
54		RESET
55			describes the reset line to vcxk hardware
56
57		REQUEST
58			describes the request line to vcxk hardware
59
60CONFIG_SYS_VCXK_<xxxx>_PORT
61
62	defines the I/O port which is connected with the line
63	for valid values for <xxxx> see CONFIG_SYS_VCXK_<xxxx>_PIN
64
65CONFIG_SYS_VCXK_<xxxx>_DDR
66
67	defines the register which configures the direction
68	for valid values for <xxxx> see CONFIG_SYS_VCXK_<xxxx>_PIN
69