Douglas Anderson 7760a47892 google/veyron*: Pulse the i2c clock once if sda was low
On one particular TV the TV was holding SDA low when it came up.  It
would release the SDA when the SCL went low the first time.
Unfortunately the HDMI i2c port wouldn't transmit until the SDA was
released.

Let's detect this case and insert a bogus clock pulse to try to get the
other side to release SDA.

It's unclear why the kernel doesn't have this problem.

BRANCH=none
BUG=chrome-os-partner:46256
TEST=Insignia TV works now

Change-Id: Ic9d27eb69bdc9c5fb11a68258e0c755cdc8b79d7
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 356ee7503f04e741a41be37ad573b588067b7114
Original-Change-Id: I4b6361877e0576cc4ea2f643f073f1aab660e434
Original-Signed-off-by: Douglas Anderson <dianders@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/309258
Original-Reviewed-by: Agnes Cheng <agnescheng@google.com>
Original-Commit-Queue: Agnes Cheng <agnescheng@google.com>
Original-Trybot-Ready: Agnes Cheng <agnescheng@google.com>
Original-Tested-by: Agnes Cheng <agnescheng@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/309546
Original-Commit-Ready: David Hendricks <dhendrix@chromium.org>
Original-Tested-by: David Hendricks <dhendrix@chromium.org>
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/12451
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
2015-11-18 16:29:16 +01:00
2012-11-01 23:13:39 +01:00
2006-08-12 22:03:36 +00:00

-------------------------------------------------------------------------------
coreboot README
-------------------------------------------------------------------------------

coreboot is a Free Software project aimed at replacing the proprietary BIOS
(firmware) found in most computers.  coreboot performs a little bit of
hardware initialization and then executes additional boot logic, called a
payload.

With the separation of hardware initialization and later boot logic,
coreboot can scale from specialized applications that run directly
firmware, run operating systems in flash, load custom
bootloaders, or implement firmware standards, like PC BIOS services or
UEFI. This allows for systems to only include the features necessary
in the target application, reducing the amount of code and flash space
required.

coreboot was formerly known as LinuxBIOS.


Payloads
--------

After the basic initialization of the hardware has been performed, any
desired "payload" can be started by coreboot.

See http://www.coreboot.org/Payloads for a list of supported payloads.


Supported Hardware
------------------

coreboot supports a wide range of chipsets, devices, and mainboards.

For details please consult:

 * http://www.coreboot.org/Supported_Motherboards
 * http://www.coreboot.org/Supported_Chipsets_and_Devices


Build Requirements
------------------

 * make
 * gcc / g++
   Because Linux distribution compilers tend to use lots of patches. coreboot
   does lots of "unusual" things in its build system, some of which break due
   to those patches, sometimes by gcc aborting, sometimes - and that's worse -
   by generating broken object code.
   Two options: use our toolchain (eg. make crosstools-i386) or enable the
   ANY_TOOLCHAIN Kconfig option if you're feeling lucky (no support in this
   case).
 * iasl (for targets with ACPI support)

Optional:

 * doxygen (for generating/viewing documentation)
 * gdb (for better debugging facilities on some targets)
 * ncurses (for 'make menuconfig' and 'make nconfig')
 * flex and bison (for regenerating parsers)


Building coreboot
-----------------

Please consult http://www.coreboot.org/Build_HOWTO for details.


Testing coreboot Without Modifying Your Hardware
------------------------------------------------

If you want to test coreboot without any risks before you really decide
to use it on your hardware, you can use the QEMU system emulator to run
coreboot virtually in QEMU.

Please see http://www.coreboot.org/QEMU for details.


Website and Mailing List
------------------------

Further details on the project, a FAQ, many HOWTOs, news, development
guidelines and more can be found on the coreboot website:

  http://www.coreboot.org

You can contact us directly on the coreboot mailing list:

  http://www.coreboot.org/Mailinglist


Copyright and License
---------------------

The copyright on coreboot is owned by quite a large number of individual
developers and companies. Please check the individual source files for details.

coreboot is licensed under the terms of the GNU General Public License (GPL).
Some files are licensed under the "GPL (version 2, or any later version)",
and some files are licensed under the "GPL, version 2". For some parts, which
were derived from other projects, other (GPL-compatible) licenses may apply.
Please check the individual source files for details.

This makes the resulting coreboot images licensed under the GPL, version 2.

Description
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ASL 2.5%
Makefile 1.1%
Pawn 0.6%
Perl 0.4%
Other 1.8%