From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH v2 1/1] input: add driver for Bosch Sensortec's BMA150 accelerometer Date: Thu, 23 Jun 2011 13:55:33 -0700 Message-ID: <20110623205532.GE14950@core.coreip.homeip.net> References: <1308840027-10724-1-git-send-email-eric.andersson@unixphere.com> <1308840027-10724-2-git-send-email-eric.andersson@unixphere.com> <20110623163631.2c43671e@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pw0-f46.google.com ([209.85.160.46]:45053 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932755Ab1FWUzm (ORCPT ); Thu, 23 Jun 2011 16:55:42 -0400 Content-Disposition: inline In-Reply-To: <20110623163631.2c43671e@lxorguk.ukuu.org.uk> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Alan Cox Cc: Eric Andersson , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, zhengguang.guo@bosch-sensortec.com, stefan.nilsson@unixphere.com, Albert Zhang On Thu, Jun 23, 2011 at 04:36:31PM +0100, Alan Cox wrote: > > + > > + > > +What: /sys/bus/i2c/devices/-/value > > +Date: May 2011 > > +Contact: Eric Andersson > > +Description: This is used to get the current acceleration values for each > > + axis. The values are represented as (x,y,z), where each axis can > > + hold a value between -512 and 511. > > + > > + Reading: returns the current acceleration values. > > This was nacked in the bma023 driver by the IIO folks - and Dmitry > pointed out you can do this without a sysfs hack. The trick is to do an > initial poll in input_open at which point the ioctl query for the > position will have data that is current and open/ioctl/close works and > providing we go nail that into other drivers that need that kind of use > the API is generic and input event based. > Right, I think the patch below will do what is needed for all polled devices. Thanks. -- Dmitry Input: polldev - immediately poll device upon opening To allow open/ioctl(EVIOCGABS)/close use pattern for polled devices read the device in context of open() call instead of offloading the first read to a workqueue. This will ensure that once call to open() returns device would have cached reasonably recent axis values that can be retrieved via appropriate ioctl. Signed-off-by: Dmitry Torokhov --- drivers/input/input-polldev.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/input/input-polldev.c b/drivers/input/input-polldev.c index b1aabde..b253973 100644 --- a/drivers/input/input-polldev.c +++ b/drivers/input/input-polldev.c @@ -49,8 +49,10 @@ static int input_open_polled_device(struct input_dev *input) dev->open(dev); /* Only start polling if polling is enabled */ - if (dev->poll_interval > 0) - queue_delayed_work(system_freezable_wq, &dev->work, 0); + if (dev->poll_interval > 0) { + dev->poll(dev); + input_polldev_queue_work(dev); + } return 0; }