From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iK0FN-0002jn-8U for barebox@lists.infradead.org; Mon, 14 Oct 2019 13:18:50 +0000 Date: Mon, 14 Oct 2019 15:18:47 +0200 From: Sascha Hauer Message-ID: <20191014131847.z7hvwp2p2qlee57s@pengutronix.de> References: <20191011162753.17100-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191011162753.17100-1-a.fatoum@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH 1/4] mfd: add basic Super I/O chip helpers To: Ahmad Fatoum Cc: barebox@lists.infradead.org On Fri, Oct 11, 2019 at 06:27:50PM +0200, Ahmad Fatoum wrote: > Super I/O chips are ICs common to x86 that are used for interfacing > to low-bandwidth peripherals. They often contain serial ports, watchdog > timers and hardware monitoring units. > > They are usually addressable via one of two I/O port pairs, either > 0x2e-0x2f or 0x4e-0x4f, but they don't typically respond to reads from > their range unless a device-specific 'password' has been poked in. > After this is done, they are read and written in the same manner however. > > On Linux, these devices aren't subject to any device/driver model. > Each driver for some function (e.g. watchdog or GPIO) duplicates the > device probe in the module_init and board-specific configuration > is handled via module parameters. > > Lets do it a bit fancier in barebox and add a helper to register chips > and a regmap for the control and configuration registers as well as a > helper to register child devices for each function contained within the > Super I/O chip. > Board-specific configuration, e.g. which pin to use as a watchdog reset, > can then be realized using barebox device-specific parameters. > > The regmap will be more of a debugging aid, however. > For ease of porting from Linux, it's expected that access to the > I/O ports won't happen via the regmap. For this reason, the new > header offers functions to read/write these chips' registers > as well. > > Signed-off-by: Ahmad Fatoum > --- Applied, thanks Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox