From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754527AbaE1IYQ (ORCPT ); Wed, 28 May 2014 04:24:16 -0400 Received: from mail-ig0-f171.google.com ([209.85.213.171]:52931 "EHLO mail-ig0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754381AbaE1IYL (ORCPT ); Wed, 28 May 2014 04:24:11 -0400 Date: Wed, 28 May 2014 09:24:05 +0100 From: Lee Jones To: Johannes Thumshirn Cc: Andreas Werner , linux-kernel@vger.kernel.org, sameo@linux.intel.com, wim@iguana.be, linux-watchdog@vger.kernel.org, cooloney@gmail.com, rpurdie@rpsys.net, linux-leds@vger.kernel.org Subject: Re: [PATCH v2 1/3] drivers/mfd/menf21bmc: introduce MEN 14F021P00 BMC MFD Core driver Message-ID: <20140528082404.GA10803@lee--X1> References: <20140527150547.GA4227@lee--X1> <20140528070222.GA24101@jtlinux> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20140528070222.GA24101@jtlinux> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > > 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'? -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog