From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Chris Wolfe <cwolfe@chromium.org>
Cc: Alan Cox <alan@linux.intel.com>,
Nathan Royer <nroyer@invensense.com>,
Andrew Morton <akpm@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@suse.de>,
Jonathan Cameron <jic23@cam.ac.uk>, Jiri Kosina <jkosina@suse.cz>,
Jean Delvare <khali@linux-fr.org>,
linux-kernel@vger.kernel.org, linux-input@vger.kernel.org
Subject: Re: [PATCH 11/11] misc: Add slave driver for bma085 pressure sensor
Date: Fri, 1 Jul 2011 15:41:50 +0100 [thread overview]
Message-ID: <20110701154150.0ac303a3@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <CAN_12A8Za7r92=r3JHx3R=AwAA7xk6=NVVMiSp68HPatb1G3hg@mail.gmail.com>
> Just to field this quickly, since I've been playing with the hardware
(Ditto)
> Part of the reason I got started on the KXTF9 driver was to try and
> understand how a normal kernel driver could cope with the "here and
> gone again" behavior of being on the MPU's secondary bus.
It's a hot pluggable bus - no different to an i2c bus on a hot pluggable
device.
I would guess however that if you knew the device was going to be used for
the mpu3050 only you'd not add the "slave" devices in your platform data
in the first place as well so they didn't bounce in and out and you'd
probably teach the mpu3050 code to not create the bus if it was then
going to destroy it again a moment later.
> The other note that may not have been made explicit yet is that the
> 3050 will happily provide unprocessed gyro and slave data without
> firmware loaded. The firmware sets up some additional processing
> capabilities of the chip, which are used by InvenSense's user-space
> products.
Yes - and the current mpu3050 driver provides just these interfaces.
Of the other stuff the slave drivers seem to be no problem as standard
i²c bus devices, the MPU mode may depend upon whether there is open
documentation, applying the standards we apply to everything else. That
is "can someone write their own tools to use that interface based upon the
documentation/source code examples available".
Eg for the ektf driver which is pending the interface is all documented
and provides rectangles of pressure data but you'll have to go write
your own gesture recognizer parts if you want to do clever stuff with it.
Alan
next prev parent reply other threads:[~2011-07-01 14:40 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-01 2:18 [PATCH 01/11] misc: inv_mpu primary header file and README file Nathan Royer
2011-07-01 2:18 ` [PATCH 02/11] misc: mpu3050 Register definition and Private data Nathan Royer
2011-07-01 2:18 ` [PATCH 03/11] misc: mpu3050 /dev/mpu implementation Nathan Royer
2011-07-01 2:18 ` [PATCH 04/11] misc: IRQ handling for MPU3050 and slave devices Nathan Royer
2011-07-01 2:18 ` [PATCH 05/11] misc: MPU3050 and slave device configuration Nathan Royer
2011-07-01 17:55 ` Nathan Royer
2011-07-01 2:18 ` [PATCH 06/11] misc: inv_mpu logging and debugging support Nathan Royer
2011-07-01 2:18 ` [PATCH 07/11] misc: I2C communication with the MPU3050 and slave devices Nathan Royer
2011-07-01 2:18 ` [PATCH 08/11] misc: Kconfig and Makefile changes for inv_mpu driver Nathan Royer
2011-07-01 17:10 ` Randy Dunlap
2011-07-01 2:18 ` [PATCH 09/11] misc: Add slave driver for kxtf9 accelerometer Nathan Royer
2011-07-01 2:18 ` [PATCH 10/11] misc: Add slave driver for ak8975 compass driver Nathan Royer
2011-07-01 2:18 ` [PATCH 11/11] misc: Add slave driver for bma085 pressure sensor Nathan Royer
2011-07-01 7:56 ` Alan Cox
2011-07-01 8:47 ` Jean Delvare
2011-07-01 14:28 ` Chris Wolfe
2011-07-01 14:41 ` Alan Cox [this message]
2011-07-01 15:52 ` Chris Wolfe
2011-07-01 17:00 ` Alan Cox
2011-07-01 17:56 ` Nathan Royer
2011-07-01 16:09 ` Jean Delvare
2011-07-01 9:05 ` Jonathan Cameron
2011-07-01 10:35 ` Manuel Stahl
2011-07-01 3:09 ` [PATCH 01/11] misc: inv_mpu primary header file and README file Greg KH
2011-07-01 7:29 ` Alan Cox
2011-07-01 9:00 ` Jonathan Cameron
2011-07-01 3:59 ` Chris Wolfe
2011-07-05 18:08 ` Nathan Royer
2011-07-01 7:53 ` Alan Cox
2011-07-01 9:08 ` Jonathan Cameron
2011-07-01 16:39 ` Nathan Royer
2011-07-03 11:29 ` Jonathan Cameron
2011-07-04 8:16 ` Alan Cox
2011-07-06 1:49 ` Nathan Royer
2011-07-06 9:07 ` Jonathan Cameron
2011-07-06 20:25 ` Nathan Royer
2011-07-06 10:54 ` Alan Cox
2011-07-06 21:27 ` Nathan Royer
2011-07-07 7:40 ` Alan Cox
2011-07-08 1:25 ` Nathan Royer
2011-07-08 11:21 ` Jonathan Cameron
2011-07-08 16:24 ` Nathan Royer
2011-07-04 20:06 ` Eric Andersson
2011-07-01 21:04 ` Arnd Bergmann
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