Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751820AbcCIT0G (ORCPT ); Wed, 9 Mar 2016 14:26:06 -0500 Received: from mail-pf0-f195.google.com ([209.85.192.195]:35102 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933890AbcCITZt (ORCPT ); Wed, 9 Mar 2016 14:25:49 -0500 From: Alison Schofield To: outreachy-kernel@googlegroups.com Cc: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Michael.Hennerich@analog.com, gregkh@linuxfoundation.org, devel@driverdev.osuosl.org Subject: [RFC PATCH v2 0/2] iio: introduce iio_device_{claim|release}_direct_mode() Date: Wed, 9 Mar 2016 11:25:23 -0800 Message-Id: X-Mailer: git-send-email 2.1.4 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1435 Lines: 34 This patchset introduces two helper functions to simplify driver code requiring the device to be locked in direct mode during execution of a code path. The staging driver ad7192 is updated to demonstrate usage. This could be applied to approximately 18 known cases where the driver is holding the lock in direct mode. Unknown cases might be those that should, but don't, hold the lock. Alternate implementation: Generalize to support a claim on any mode. Do iio_claim_mode(device,mode) where if the device is in *mode*, it is guaranteed to stay that way until release is called. I considered and rejected this option because a) not sure other modes would ever need to be locked, and b) the semantic improvement is less when it is generalized. This patchset was inspired by a discussion on linux-iio: http://www.spinics.net/lists/linux-iio/msg18540.html Changes in v2: o use iio_device prefix for new functions o replace EINVAL with EBUSY on failure to claim direct mode o update commit msg & changelog to reflect new prefix Alison Schofield (2): iio: core: implement iio_device_{claim|release}_direct_mode() staging: iio: ad7192: use iio_device_{claim|release}_direct_mode() drivers/iio/industrialio-core.c | 39 +++++++++++++++++++++++++++++++++++++++ drivers/staging/iio/adc/ad7192.c | 24 +++++++++--------------- include/linux/iio/iio.h | 2 ++ 3 files changed, 50 insertions(+), 15 deletions(-) -- 2.1.4