Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751725AbaAWLwY (ORCPT ); Thu, 23 Jan 2014 06:52:24 -0500 Received: from gw-1.arm.linux.org.uk ([78.32.30.217]:46322 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751587AbaAWLwP (ORCPT ); Thu, 23 Jan 2014 06:52:15 -0500 Date: Thu, 23 Jan 2014 11:52:03 +0000 From: Russell King - ARM Linux To: Lothar =?iso-8859-1?Q?Wa=DFmann?= Cc: Sascha Hauer , Mark Rutland , linux-pwm@vger.kernel.org, Rob Landley , Pawel Moll , Ian Campbell , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Rob Herring , Thierry Reding , Sascha Hauer , Kumar Gala , Shawn Guo , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCHv2 2/2] pwm: imx: support polarity inversion Message-ID: <20140123115203.GV15937@n2100.arm.linux.org.uk> References: <1389859585-14006-1-git-send-email-LW@KARO-electronics.de> <1389859585-14006-3-git-send-email-LW@KARO-electronics.de> <20140116160356.GY16215@pengutronix.de> <20140123083714.3c6e86ae@ipc1.ka-ro> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20140123083714.3c6e86ae@ipc1.ka-ro> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 23, 2014 at 08:37:14AM +0100, Lothar Wa?mann wrote: > This wouldn't buy much without a material change to of_pwm_get(). > The function of_parse_phandle_with_args() called by of_pwm_get() > requires the number of args in the pwms property be greater or equal to > the #pwm-cells property in the pwm node. Thus, the interesting case of > having #pwm-cells = <3> without changing the existing users is > prohibited by of_parse_phandle_with_args(). I really don't think that's a problem we need to be concerned with at the moment. What we need is for the kernel to be able to parse files with #pwm-cells = <2> with the pwms property containing two arguments, and when they're updated to #pwm-cells = <3> with the pwms property containing three arguments. Yes, that means all the board dt files need to be updated at the same time to include the additional argument, but I don't see that as a big problem. What we do need to do is to adjust the PWM parsing code such that it's possible to use either specification without causing any side effects. I would test this, but as u-boot is rather fscked at the moment and the networking has broken on my cubox-i as a result... and it seems that the u-boot developers have pissed off cubox-i u-boot hackers soo much that they've dropped u-boot in favour of barebox... drivers/pwm/core.c | 59 +++++++++++++++++++++++++++++------------------------ include/linux/pwm.h | 2 ++ 2 files changed, 34 insertions(+), 27 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 2ca95042a0b9..40adbce8ef0c 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -132,14 +132,11 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) } struct pwm_device * -of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) +of_pwm_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) { struct pwm_device *pwm; - if (pc->of_pwm_n_cells < 3) - return ERR_PTR(-EINVAL); - - if (args->args[0] >= pc->npwm) + if (args->args_count < 2) return ERR_PTR(-EINVAL); pwm = pwm_request_from_chip(pc, args->args[0], NULL); @@ -148,33 +145,45 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) pwm_set_period(pwm, args->args[1]); - if (args->args[2] & PWM_POLARITY_INVERTED) - pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); - else - pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); + if (args->args_count > 2) { + int err; + + if (args->args[2] & PWM_POLARITY_INVERTED) + err = pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); + else + err = pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); + + pwm_put(pwm); + return ERR_PTR(err); + } return pwm; } +EXPORT_SYMBOL(of_pwm_xlate); + +struct pwm_device * +of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) +{ + if (pc->of_pwm_n_cells < 3) + return ERR_PTR(-EINVAL); + + if (args->args_count != pc->of_pwm_n_cells) + return ERR_PTR(-EINVAL); + + return of_pwm_xlate(pc, args); +} EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); static struct pwm_device * of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) { - struct pwm_device *pwm; - if (pc->of_pwm_n_cells < 2) return ERR_PTR(-EINVAL); - if (args->args[0] >= pc->npwm) + if (args->args_count != pc->of_pwm_n_cells) return ERR_PTR(-EINVAL); - pwm = pwm_request_from_chip(pc, args->args[0], NULL); - if (IS_ERR(pwm)) - return pwm; - - pwm_set_period(pwm, args->args[1]); - - return pwm; + return of_pwm_xlate(pc, args); } static void of_pwmchip_add(struct pwm_chip *chip) @@ -536,16 +545,12 @@ struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) goto put; } - if (args.args_count != pc->of_pwm_n_cells) { - pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, - args.np->full_name); - pwm = ERR_PTR(-EINVAL); - goto put; - } - pwm = pc->of_xlate(pc, &args); - if (IS_ERR(pwm)) + if (IS_ERR(pwm)) { + pr_debug("%s: of_xlate failed for %s: %d\n", np->full_name, + args.np->full_name, (int)PTR_ERR(pwm)); goto put; + } /* * If a consumer name was not given, try to look it up from the diff --git a/include/linux/pwm.h b/include/linux/pwm.h index f0feafd184a0..14a823f77c31 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -188,6 +188,8 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, unsigned int index, const char *label); +struct pwm_device *of_pwm_xlate(struct pwm_chip *pc, + const struct of_phandle_args *args); struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args); -- FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad. Estimate before purchase was "up to 13.2Mbit". -- 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/