Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751967AbbGOIo5 (ORCPT ); Wed, 15 Jul 2015 04:44:57 -0400 Received: from eusmtp01.atmel.com ([212.144.249.243]:53045 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751032AbbGOIoy (ORCPT ); Wed, 15 Jul 2015 04:44:54 -0400 Date: Wed, 15 Jul 2015 10:45:42 +0200 From: Ludovic Desroches To: Sascha Hauer CC: Ludovic Desroches , , , , , , , Subject: Re: [RESEND PATCH 2/2] pinctrl: introduce complex pin description Message-ID: <20150715084542.GC14886@odux.rfo.atmel.com> Mail-Followup-To: Sascha Hauer , linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, swarren@wwwdotorg.org, linus.walleij@linaro.org, nicolas.ferre@atmel.com References: <1433948699-19800-1-git-send-email-ludovic.desroches@atmel.com> <1433948699-19800-3-git-send-email-ludovic.desroches@atmel.com> <20150714061359.GC5161@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20150714061359.GC5161@pengutronix.de> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3731 Lines: 93 On Tue, Jul 14, 2015 at 08:13:59AM +0200, Sascha Hauer wrote: > On Wed, Jun 10, 2015 at 05:04:57PM +0200, Ludovic Desroches wrote: > > Using a string to describe a pin in the device tree can be not enough. > > Some controllers may need extra information to fully describe a pin. It > > concerns mainly controllers which have a per pin muxing approach which > > don't fit well the notions of groups and functions. > > Instead of using a pin name, a 32 bit value is used. The 16 least > > significant bits are used for the pin number. Other 16 bits can be used to > > store extra parameters. > > In the Mediatek driver we use 'pinmux' as name for the property > containing the combined pin number / mux value defines. 'pinmux' better > describes what it is... > At the moment, I don't mix pin number and pin mux. I mix pin number and ioset. It allows to check that all the pins belong to the same ioset. As said previously, I didn't want to mix pin mux and pin conf in the same node (but it is something I can do, it's not a problem on my side). If I do it I will have to mux three values: pin number, pin mux value and pin ioset. So assuming I do this change, your advice is to add a 'pinmux' property in addition of 'pins' instead of trying to use it? > > + > > + if (pctldesc->complex_pin_desc) > > + ret = of_property_count_u32_elems(np, "pins"); > > + else > > + ret = of_property_count_strings(np, "pins"); > > ... and has the advantage that you don't have to pass in a > complex_pin_desc variable from the driver as the different property > name inherently carries this information. 'pins' can then stay a > property containing only strings. > > > if (ret < 0) { > > ret = of_property_count_strings(np, "groups"); > > if (ret < 0) > > @@ -297,11 +305,12 @@ int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev, > > if (type == PIN_MAP_TYPE_INVALID) > > type = PIN_MAP_TYPE_CONFIGS_GROUP; > > subnode_target_type = "groups"; > > + pins_prop = false; > > } else { > > if (type == PIN_MAP_TYPE_INVALID) > > type = PIN_MAP_TYPE_CONFIGS_PIN; > > } > > - strings_count = ret; > > + items_count = ret; > > > > ret = of_property_read_string(np, "function", &function); > > if (ret < 0) { > > @@ -326,17 +335,31 @@ int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev, > > if (num_configs) > > reserve++; > > > > - reserve *= strings_count; > > + reserve *= items_count; > > > > ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps, > > num_maps, reserve); > > if (ret < 0) > > goto exit; > > > > - of_property_for_each_string(np, subnode_target_type, prop, group) { > > + items_name = kmalloc_array(items_count, sizeof(char *), GFP_KERNEL); > > + if (!items_name) > > + goto exit; > > + if (pctldesc->complex_pin_desc && pins_prop) { > > + of_property_for_each_u32(np, subnode_target_type, prop, cur, val) { > > + pin_id = val & PINCTRL_PIN_MASK; > > + items_name[i++] = pctldesc->pins[pin_id].name; > > + } > > I don't like that even though pins have numbers here they are converted > to strings which the driver later has to search in a list just to > convert it back into the number. This is quite inefficient. > > I guess this could be optimized later, but it would be nice to have the > pin number directly in the driver. I know that is something you don't like but, at the moment, I need a string for pinctrl_utils_add_map_mux and pinctrl_utils_add_map_configs. Ludovic -- 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/