Go to file
Andrew Jeffery 95fd3ad9cd i2c: aspeed: Retain delay/setup/hold values when configuring bus frequency
In addition to the base, low and high clock configuration, the AC timing
register #1 on the AST2400 houses fields controlling:

1. tBUF: Minimum delay between Stop and Start conditions
2. tHDSTA: Hold time for the Start condition
3. tACST: Setup time for Start and Stop conditions, and hold time for the
   Repeated Start condition

These values are defined in hardware on the AST2500 and therefore don't
need to be set.

aspeed_i2c_init_clk() was performing a direct write of the generated
clock values rather than a read/mask/modify/update sequence to retain
tBUF, tHDSTA and tACST, and therefore cleared the tBUF, tHDSTA and tACST
fields on the AST2400. This resulted in a delay/setup/hold time of 1
base clock, which in some configurations is not enough for some devices
(e.g. the MAX31785 fan controller, with an APB of 48MHz and a desired
bus speed of 100kHz).

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-08-28 18:05:03 +02:00
arch blackfin: merge the two TWI header files 2017-08-27 15:37:18 +02:00
block blk-mq: map queues to all present CPUs 2017-07-24 10:01:31 -06:00
certs modsign: add markers to endif-statements in certs/Makefile 2017-07-14 11:01:37 +10:00
crypto crypto: authencesn - Fix digest_null crash 2017-07-18 17:01:11 +08:00
Documentation dt-bindings: i2c: eeprom: Document vendor to be used and deprecated ones 2017-08-28 17:40:36 +02:00
drivers i2c: aspeed: Retain delay/setup/hold values when configuring bus frequency 2017-08-28 18:05:03 +02:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs A large number of ext4 bug fixes and cleanups for v4.13 2017-08-06 12:31:17 -07:00
include blackfin: merge the two TWI header files 2017-08-27 15:37:18 +02:00
init random: do not ignore early device randomness 2017-07-12 16:26:00 -07:00
ipc ipc: add missing container_of()s for randstruct 2017-08-02 17:16:12 -07:00
kernel Fix compat_sys_sigpending breakage 2017-08-06 11:48:27 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-07-31 22:36:42 -07:00
mm mm: take memory hotplug lock within numa_zonelist_order_handler() 2017-08-02 17:16:11 -07:00
net A bunch of fixes and follow-ups for -rc1 Luminous patches: issues with 2017-08-04 10:15:11 -07:00
samples samples/bpf: fix bpf tunnel cleanup 2017-07-31 22:02:47 -07:00
scripts DeviceTree fixes for 4.13: 2017-07-28 17:21:41 -07:00
security Now that IPC and other changes have landed, enable manual markings for 2017-07-19 08:55:18 -07:00
sound ASoC: Fixes for v4.13 2017-08-02 17:11:45 +02:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-07-31 22:36:42 -07:00
usr ramfs: clarify help text that compression applies to ramfs as well as legacy ramdisk. 2017-07-06 16:24:30 -07:00
virt KVM/ARM Fixes for v4.13-rc4 2017-08-03 17:59:58 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap power supply and reset changes for the v4.12 series (part 2) 2017-05-12 12:02:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS MAINTAINERS: drop entry for Blackfin I2C and Sonic's email 2017-08-27 15:38:11 +02:00
Makefile Linux 4.13-rc4 2017-08-06 18:44:49 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.