From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752802AbaE1K7d (ORCPT ); Wed, 28 May 2014 06:59:33 -0400 Received: from mail1.bemta14.messagelabs.com ([193.109.254.117]:13911 "EHLO mail1.bemta14.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752502AbaE1K7b (ORCPT ); Wed, 28 May 2014 06:59:31 -0400 X-Env-Sender: Andreas.Werner@men.de X-Msg-Ref: server-15.tower-193.messagelabs.com!1401274767!16512042!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 Wed, 28 May 2014 12:59:28 +0200 Date: Wed, 28 May 2014 13:51:59 +0200 From: Andreas Werner To: Lee Jones CC: Johannes Thumshirn , Andreas Werner , , , , , , , Subject: Re: [PATCH v2 1/3] drivers/mfd/menf21bmc: introduce MEN 14F021P00 BMC MFD Core driver Message-ID: <20140528115159.GA2090@awelinux> References: <20140527150547.GA4227@lee--X1> <20140528070222.GA24101@jtlinux> <20140528082404.GA10803@lee--X1> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20140528082404.GA10803@lee--X1> 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 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. Regards Andy > -- > Lee Jones > Linaro STMicroelectronics Landing Team Lead > Linaro.org │ Open source software for ARM SoCs > Follow Linaro: Facebook | Twitter | Blog