From 67dfd54c2d83a76a5756760f7fee0c8cfac52b1c Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jean-Fran=C3=A7ois=20Dagenais?= Date: Thu, 26 May 2011 16:26:01 -0700 Subject: [PATCH] w1: add 1-wire (w1) reset and resume command API support MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The first patch adds generic functionnality to w1_io for Resume Command [A5h] lots of slaves support. I found it useful for multi-commands/reset workflows with the same slave on a multi-slave bus. This DS2408 w1 slave driver is not complete for all the features of the chip, but its sufficient if you use it as a simple IO expander. Enjoy! The ds1wm had Kconfig dependencies towards ARM && HAVE_CLK. I took them out since I was using the ds1wm on an x86_64 platform (ds1wm in a FPGA through pcie) and found them irrelevant. The clock freq/divisors at the top of ds1wm.c did not have the MSB set to 1. This bit is CLK_EN which turns the whole prescaler and dividers on. The driver never mentionned this bit either, so I just included this bit right in the table entries. I also took the liberty to add a couple of entries to the table. The spec doesn't explicitely mentions these possibilities but the description and examination of the core shows the prescalers & dividers can be used for more than the table explicitely shows. The table I enlarged still doesn't cover all possibilities, but it's a good start. I also made a few tweaks to a couple of the read and write algorithms which made sense while I had my head very deep in the ds1wm documentation. We stressed it a lot with 10+ slaves on the bus, many ds2408, ds2431 and ds2433 at the same time doing extensive interaction. It proved quite stable in our production environment. This patch: Add generic functionnality to w1_io for Resume Command [A5h] lots of slaves support. Signed-off-by: Jean-François Dagenais Cc: Evgeniy Polyakov Cc: Szabolcs Gyurko Cc: Matt Reimer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-format-patch failed