From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matti Vaittinen Subject: Re: [RFC PATCH v2 08/10] rtc: bd70528: Initial support for ROHM bd70528 RTC Date: Mon, 28 Jan 2019 18:16:59 +0200 Message-ID: <20190128161659.GA2121@localhost.localdomain> References: <20190125110536.GA29321@localhost.localdomain> <35bbc5b9-5f8c-ec80-3eaa-bb2c0e2812c9@roeck-us.net> <20190128074849.GB2030@localhost.localdomain> <11ff93bf-c71f-7489-841f-09bf757a8ba7@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <11ff93bf-c71f-7489-841f-09bf757a8ba7@roeck-us.net> Sender: linux-kernel-owner@vger.kernel.org To: Guenter Roeck Cc: mazziesaccount@gmail.com, heikki.haikola@fi.rohmeurope.com, mikko.mutanen@fi.rohmeurope.com, lee.jones@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com, broonie@kernel.org, gregkh@linuxfoundation.org, rafael@kernel.org, mturquette@baylibre.com, sboyd@kernel.org, linus.walleij@linaro.org, bgolaszewski@baylibre.com, sre@kernel.org, lgirdwood@gmail.com, a.zummo@towertech.it, alexandre.belloni@bootlin.com, wim@linux-watchdog.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, linux-pm@vger.kernel.org, linux-rtc@vger.kernel.org, linux-watchdog@vger.kernel.org List-Id: devicetree@vger.kernel.org On Mon, Jan 28, 2019 at 06:02:47AM -0800, Guenter Roeck wrote: > On 1/27/19 11:48 PM, Matti Vaittinen wrote: > > Thanks again Guenter, > > > > On Sat, Jan 26, 2019 at 08:30:24AM -0800, Guenter Roeck wrote: > > > On 1/25/19 3:05 AM, Matti Vaittinen wrote: > > > > +/* > > > > + * We read regs RTC_SEC => RTC_YEAR > > > > + * this struct is ordered according to chip registers. > > > > + * Keep it u8 only to avoid padding issues. > > > > + */ > > > > +struct bd70528_rtc_day { > > > > + u8 sec; > > > > + u8 min; > > > > + u8 hour; > > > > +}; > > > > + > > > > +struct bd70528_rtc_data { > > > > + struct bd70528_rtc_day time; > > > > + u8 week; > > > > + u8 day; > > > > + u8 month; > > > > + u8 year; > > > > +}; > > > > + > > > > +struct bd70528_rtc_wake { > > > > + struct bd70528_rtc_day time; > > > > + u8 ctrl; > > > > +}; > > > > + > > > > +struct bd70528_rtc_alm { > > > > + struct bd70528_rtc_data data; > > > > + u8 alm_mask; > > > > + u8 alm_repeat; > > > > +}; > > > > > > At least some of the above are directly associated with chip registers. > > > I don't think this will work for all architectures without explicit packed > > > attribute. > > > > Allright. I was thinking of that but thought that most of the > > architectures using this PMIC would handle alignments fine if I used > > only u8 members. I did consider using __attribute__((packed)) - but I'm > > not sure if we hit into troubles with that too. I guess some people > > would like to compile kernel with other compiler(s) but gcc - although > > I'm not sure if this should be taken into account. I'll try doing some > > study on this - unless someone replies to this and just tells how this > > should be done. (I am pretty sure I can find the answer from mail > > archives though). I'll try adding some packing hint for compiler at v3. > > > > Use __packed ? Right. That appends to __attribute__((packed)) on gcc. I'll use that. Thanks for the tip :) Br, Matti Vaittinen