From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754749Ab1LDQrR (ORCPT ); Sun, 4 Dec 2011 11:47:17 -0500 Received: from mail-ey0-f174.google.com ([209.85.215.174]:45625 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754665Ab1LDQrN (ORCPT ); Sun, 4 Dec 2011 11:47:13 -0500 From: Hubert Feurstein To: zbr@ioremap.net, jeff.dagenais@gmail.com Cc: linux-kernel@vger.kernel.org, Hubert Feurstein Subject: [PATCH v2] w1: add fast search for single slave bus Date: Sun, 4 Dec 2011 17:46:50 +0100 Message-Id: <1323017210-14666-1-git-send-email-h.feurstein@gmail.com> X-Mailer: git-send-email 1.7.7.4 In-Reply-To: <258EF057-8FF6-4432-A9E5-77F87607C45F@gmail.com> References: <258EF057-8FF6-4432-A9E5-77F87607C45F@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This enables a much more efficient way of device searching. It uses the 1-wire read-rom operation which allows the direct reading of the slave address. BUT this works only with exactly one slave on the bus. Signed-off-by: Hubert Feurstein --- v2: remove config option drivers/w1/w1.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index c374978..9761950 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -892,6 +892,16 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb break; } + /* Do fast search on single slave bus */ + if (dev->max_slave_count == 1) { + w1_write_8(dev, W1_READ_ROM); + + if (w1_read_block(dev, (u8 *)&rn, 8) == 8 && rn) + cb(dev, rn); + + break; + } + /* Start the search */ w1_write_8(dev, search_type); for (i = 0; i < 64; ++i) { -- 1.7.7.4