xref: /openbmc/u-boot/doc/README.bus_vcxk (revision b3820ba9)
1SPDX-License-Identifier: GPL-2.0+
2/*
3 * (C) Copyright 2008-2009
4 * BuS Elektronik GmbH & Co. KG <www.bus-elektronik.de>
5 * Jens Scharsig <esw@bus-elektronik.de>
6 */
7
8U-Boot vcxk video controller driver
9======================================
10
11By defining CONFIG_VIDEO_VCXK this driver can be used with VC2K, VC4K and
12VC8K devices on following boards:
13
14board           | ARCH          | Vendor
15-----------------------------------------------------------------------
16EB+CPU5282-T1   | MCF5282       | BuS Elektronik GmbH & Co. KG
17EB+MCF-EVB123   | MCF5282       | BuS Elektronik GmbH & Co. KG
18EB+CPUx9K2      | AT91RM9200    | BuS Elektronik GmbH & Co. KG
19ZLSA            | AT91RM9200    | Ruf Telematik AG
20
21Driver configuration
22--------------------
23
24The driver needs some defines to describe the target hardware:
25
26CONFIG_SYS_VCXK_BASE
27
28	base address of VCxK hardware memory
29
30CONFIG_SYS_VCXK_DEFAULT_LINEALIGN
31
32	defines the physical alignment of a pixel row
33
34CONFIG_SYS_VCXK_DOUBLEBUFFERED
35
36	some boards that use vcxk prevent read from framebuffer memory.
37	define this option to enable double buffering (needs 16KiB RAM)
38
39CONFIG_SYS_VCXK_<xxxx>_PIN
40
41	defines the number of the I/O line PIN in the port
42	valid values for <xxxx> are:
43
44		ACKNOWLEDGE
45			describes the acknowledge line from vcxk hardware
46
47		ENABLE
48			describes the enable line to vcxk hardware
49
50		INVERT
51			describes the invert line to vcxk hardware
52
53		RESET
54			describes the reset line to vcxk hardware
55
56		REQUEST
57			describes the request line to vcxk hardware
58
59CONFIG_SYS_VCXK_<xxxx>_PORT
60
61	defines the I/O port which is connected with the line
62	for valid values for <xxxx> see CONFIG_SYS_VCXK_<xxxx>_PIN
63
64CONFIG_SYS_VCXK_<xxxx>_DDR
65
66	defines the register which configures the direction
67	for valid values for <xxxx> see CONFIG_SYS_VCXK_<xxxx>_PIN
68