Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752757AbaFBHOQ (ORCPT ); Mon, 2 Jun 2014 03:14:16 -0400 Received: from mail1.bemta5.messagelabs.com ([195.245.231.150]:8513 "EHLO mail1.bemta5.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751442AbaFBHON (ORCPT ); Mon, 2 Jun 2014 03:14:13 -0400 X-Env-Sender: Andreas.Werner@men.de X-Msg-Ref: server-2.tower-179.messagelabs.com!1401693249!30150236!1 X-Originating-IP: [80.255.6.145] X-StarScan-Received: X-StarScan-Version: 6.11.3; banners=-,-,- X-VirusChecked: Checked X-PGP-Universal: processed; by keys.men.de on Mon, 02 Jun 2014 09:14:10 +0200 Date: Mon, 2 Jun 2014 10:06:36 +0200 From: Andreas Werner To: Guenter Roeck CC: Andreas Werner , Lee Jones , Johannes Thumshirn , , , , , , , Subject: Re: [PATCH v2 1/3] drivers/mfd/menf21bmc: introduce MEN 14F021P00 BMC MFD Core driver Message-ID: <20140602080635.GA364@awelinux> References: <20140527150547.GA4227@lee--X1> <20140528070222.GA24101@jtlinux> <20140528082404.GA10803@lee--X1> <20140528115159.GA2090@awelinux> <5385E4C9.2010204@roeck-us.net> <5385EA38.9090200@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <5385EA38.9090200@roeck-us.net> User-Agent: Mutt/1.5.23 (2014-03-12) X-Originating-IP: [192.1.1.171] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 28, 2014 at 06:52:56AM -0700, Guenter Roeck wrote: > On 05/28/2014 06:29 AM, Guenter Roeck wrote: > >On 05/28/2014 04:51 AM, Andreas Werner wrote: > >>aOn Wed, May 28, 2014 at 09:24:05AM +0100, Lee Jones wrote: > >>>>>>The MEN 14F021P00 Board Management Controller provides an > >>>>>>I2C interface to the host to access the feature implemented in the BMC. > >>>>>>The BMC is a PIC Microntroller assembled on CPCI Card from MEN Mikroelektronik > >>>>>>and on a few Box/Display Computer. > >>>>>> > >>>>>>Added MFD Core driver, supporting the I2C communication to the device. > >>>>>> > >>>>>>The MFD driver currently supports the following features: > >>>>>> - Watchdog > >>>>>> - LEDs > >>>>>> > >>>>>>Signed-off-by: Andreas Werner > >>>>>>--- > >>>>>> drivers/mfd/Kconfig | 12 +++ > >>>>>> drivers/mfd/Makefile | 1 + > >>>>>> drivers/mfd/menf21bmc.c | 220 ++++++++++++++++++++++++++++++++++++++++++ > >>>>>> include/linux/mfd/menf21bmc.h | 31 ++++++ > >>>>>> 4 files changed, 264 insertions(+) > >>>>>> create mode 100644 drivers/mfd/menf21bmc.c > >>>>>> create mode 100644 include/linux/mfd/menf21bmc.h > >>> > >>>[...] > >>> > >>>>>>+static int menf21bmc_write_byte(struct i2c_client *client, u8 val) > >>>>>>+{ > >>>>>>+ int ret; > >>>>>>+ struct menf21bmc *data = i2c_get_clientdata(client); > >>>>>>+ > >>>>>>+ mutex_lock(&data->lock); > >>>>>>+ ret = i2c_smbus_write_byte(client, val); > >>>>>>+ mutex_unlock(&data->lock); > >>>>>>+ > >>>>>>+ return ret; > >>>>>>+} > >>>>> > >>>>>Didn't we ask you to remove these? Just make the i2c_smbus_* calls > >>>>>from within the driver. The I2C subsystem conducts its own locking. > >>>>>I'm really starting to frown on aggregation for the sake of > >>>>>aggregation. It's just overhead. > >>>>> > >>>> > >>>>Correct me if I'm wrong but as far as I remember Guenther asked to retain the > >>>>original API, not the remove the "abstraction layer". Once we build a board with > >>>>one of these BMCs attached via e.g. SPI we would have to reintroduce it anyways, > >>>>in order to re-use these drivers. > >>> > >>>If there are two or more possible interfaces then I agree, these > >>>aggregations would be the best approach. However, as it stands, that's > >>>not currently the case. > >>> > >>>Genuine question; are Men on the verge of building such a board, or > >>>are we talking about 'ifs' and 'maybes'? > >>> > >> > >>I think it was a missunderstanding. I also thought that i just > >>have to adapt the wrapper to the original API, that is what I did in the patch, > >>and not to delete the functions completly. > >> > >>Anayway, we currently have another project which use a STM32 MCR connected to USB. > >>A nice feature of this STM is to update the firmware using the USB interface. > >>This is easy to implement and fast. > >> > >>We want to use such a functionality in all of our MCRs to easily update the firmware > >>at the customer if we found a bug. > >> > >>We also plan to have a BMC connected to USB. Then we have i2c and USB. > >> > > > >Even more likely that you would have to change the API in that case to be less > >I2C centric. > > > > ... especially since you have "struct i2c_client *client" in your API function. > > Guenter > > Ok I agree. I will change that and delete the wrapper functions completley. I will prepare and send a v3. Thanks for the discussion. Regards Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/