Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751752Ab2H0EeA (ORCPT ); Mon, 27 Aug 2012 00:34:00 -0400 Received: from avon.wwwdotorg.org ([70.85.31.133]:53000 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750771Ab2H0Ed6 (ORCPT ); Mon, 27 Aug 2012 00:33:58 -0400 Message-ID: <503AF8B4.1070206@wwwdotorg.org> Date: Sun, 26 Aug 2012 21:33:56 -0700 From: Stephen Warren User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: Sebastian Hesselbarth CC: Thomas Petazzoni , Grant Likely , Rob Herring , Rob Landley , Russell King , Lior Amsalem , Andrew Lunn , Gregory CLEMENT , Ben Dooks , Linus Walleij , devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 1/9] pinctrl: mvebu: pinctrl driver core References: <1344689809-6223-1-git-send-email-sebastian.hesselbarth@gmail.com> <1345623750-10645-1-git-send-email-sebastian.hesselbarth@gmail.com> <1345623750-10645-2-git-send-email-sebastian.hesselbarth@gmail.com> <5035445B.6000500@wwwdotorg.org> <50366E44.4030606@wwwdotorg.org> <50369305.6050304@gmail.com> <50369FEE.8000003@wwwdotorg.org> <5036B639.20608@gmail.com> <5036F651.4020700@wwwdotorg.org> <5038F50E.7030807@gmail.com> In-Reply-To: <5038F50E.7030807@gmail.com> X-Enigmail-Version: 1.5a1pre Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1918 Lines: 48 On 08/25/2012 08:53 AM, Sebastian Hesselbarth wrote: > On 08/24/2012 05:34 AM, Stephen Warren wrote: >> On 08/23/2012 05:01 PM, Sebastian Hesselbarth wrote: >>> So possible, valid combinations for uart1 would be: >>> (a) mpp_uart1; >>> (b) mpp_uart1, mpp2, mpp3; >>> (c) mpp_uart1, mpp21, mpp22; >>> (d) mpp_uart1, mpp2, mpp22; >>> (e) mpp_uart1, mpp21, mpp3; >>> [...] >> In the example above, there is a single function named "uart1". If this >> was all the HW supported, I'd expect the driver's >> pinmux_ops.get_functions_count() to return 1, >> pinmux_ops.get_function_name(0) to return "uart1", and >> pinmux_ops.get_function_name(n>0) to return an error. >> >> In practice, I assume there are many other options that can be muxed >> onto mpp2/3/21/22/uart1, so they'd be included in the list as well. >> >> I don't expect any scanning, no. I'd expect that tables provided by the >> SoC-specific drivers to be: >> >> * A table of pins >> * A table of groups >> * A table of functions >> >> No scanning involved. > > Stephen, > > now I do understand but in the current driver we pass pingroups associated > with the available functions, i.e. "mpp2" with "uart1", "uart2", > "sdio0", aso. > IMHO for the above three functions it would be better to have functions > associated > with the corresponding groups, i.e. "uart1" with "mpp_uart1", "mpp2", > "mpp3", aso. The pinctrl subsystem does expect a list of functions, and for each function, a list of the groups where it can be selected. I admit that when I think about this, it's slightly backward, since HW typically has a list of pins/groups, and for each, a certain set of functions can be selected. Oh well... -- 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/