Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758135Ab3IBDdt (ORCPT ); Sun, 1 Sep 2013 23:33:49 -0400 Received: from mail-db9lp0250.outbound.messaging.microsoft.com ([213.199.154.250]:6336 "EHLO db9outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755458Ab3IBDdq convert rfc822-to-8bit (ORCPT ); Sun, 1 Sep 2013 23:33:46 -0400 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: 1 X-BigFish: VS1(z551biz1432Izz1f42h208ch1ee6h1de0h1fdah2073h1202h1e76h1d1ah1d2ah1fc6hzzz2dh2a8h839h8e2h8e3h944hd25hf0ah1220h1288h12a5h12a9h12bdh137ah13b6h1441h1504h1537h153bh15d0h162dh1631h1758h18e1h1946h19b5h1ad9h1b0ah1b2fh1fb3h1d0ch1d2eh1d3fh1dfeh1dffh1e1dh1fe8h1ff5hbe9i1155h) From: Xiubo Li-B47053 To: Sascha Hauer CC: Guo Shawn-R65073 , "thierry.reding@gmail.com" , "grant.likely@linaro.org" , "linux@arm.linux.org.uk" , "rob@landley.net" , "ian.campbell@citrix.com" , "swarren@wwwdotorg.org" , "mark.rutland@arm.com" , "pawel.moll@arm.com" , "rob.herring@calxeda.com" , "linux-arm-kernel@lists.infradead.org" , "linux-pwm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-doc@vger.kernel.org" , Lu Jingchang-B35083 Subject: RE: [PATCHv2 1/4] pwm: Add Freescale FTM PWM driver support Thread-Topic: [PATCHv2 1/4] pwm: Add Freescale FTM PWM driver support Thread-Index: AQHOpWawpFOEIhAI/kueoxNTb0lp2ZmuB6eAgAO48QA= Date: Mon, 2 Sep 2013 03:33:37 +0000 Message-ID: <1DD289F6464F0949A2FCA5AA6DC23F827F785F@039-SN2MPN1-011.039d.mgd.msft.net> References: <1377856132-11290-1-git-send-email-Li.Xiubo@freescale.com> <1377856132-11290-2-git-send-email-Li.Xiubo@freescale.com> <20130830174909.GF30088@pengutronix.de> In-Reply-To: <20130830174909.GF30088@pengutronix.de> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.192.208.56] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-OriginatorOrg: freescale.com X-FOPE-CONNECTOR: Id%0$Dn%*$RO%0$TLS%0$FQDN%$TlsDn% Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3542 Lines: 135 > > +static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device > > +*pwm) { > > + struct fsl_pwm_chip *fpc; > > + struct fsl_pwm_data *pwm_data; > > + > > + fpc = to_fsl_chip(chip); > > + > > + pwm_data = pwm_get_chip_data(pwm); > > + if (!pwm_data) > > + return; > > THis check seems unnecessary. > But if do not check it here, I must check it in the following code. > > + > > + if (pwm_data->available != FSL_AVAILABLE) > > + return; > > + So the ' struct fsl_pwm_data' may be removed in the future. > > > + > > + > > + pwm_data->period_cycles = period_cycles; > > + pwm_data->duty_cycles = duty_cycles; > > These fields are set but never read. Please drop them. > > If you drop the 'available' field also the you can drop chip_data > completely. > I think I may move the 'available' field to the PWM driver data struct. > > + > > + writel(FTMCnSC_MSB | FTMCnSC_ELSB, fpc->base + FTM_CSC(pwm->hwpwm)); > > + > > + writel(0xF0, fpc->base + FTM_OUTMASK); > > + writel(0x0F, fpc->base + FTM_OUTINIT); > > + writel(FTM_CNTIN_VAL, fpc->base + FTM_CNTIN); > > + > > + writel(period_cycles + cntin - 1, fpc->base + FTM_MOD); > > + writel(duty_cycles + cntin, fpc->base + FTM_CV(pwm->hwpwm)); > > + > > + return 0; > > +} > > + > > +static int fsl_pwm_set_polarity(struct pwm_chip *chip, struct > pwm_device *pwm, > > + enum pwm_polarity polarity) > > +{ > > + unsigned long reg; > > + struct fsl_pwm_data *pwm_data; > > + struct fsl_pwm_chip *fpc; > > + > > + fpc = to_fsl_chip(chip); > > + > > + pwm_data = pwm_get_chip_data(pwm); > > + if (!pwm_data) > > + return -EINVAL; > > + > > + if (pwm_data->available != FSL_AVAILABLE) > > + return -EINVAL; > > + > > + reg = readl(fpc->base + FTM_POL); > > + reg &= ~BIT(pwm->hwpwm); > > Either drop this line... > This is just for unmasking this bit field. Here it's not needed, so I will revise it. > > + if (polarity == PWM_POLARITY_INVERSED) > > + reg |= BIT(pwm->hwpwm); > > + else > > + reg &= ~BIT(pwm->hwpwm); > > ...or this one > > > +static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device > > +*pwm) { > > + int ret; > > + struct fsl_pwm_chip *fpc; > > + struct pinctrl_state *pins_state; > > + struct fsl_pwm_data *pwm_data; > > + const char *statename; > > + > > + fpc = to_fsl_chip(chip); > > + > > + pwm_data = pwm_get_chip_data(pwm); > > + if (!pwm_data) > > + return -EINVAL; > > + > > + if (pwm_data->available != FSL_AVAILABLE) > > + return -EINVAL; > > + > > + statename = kasprintf(GFP_KERNEL, "ch%d-active", pwm->hwpwm); > > You loose memory here and in fsl_pwm_disable aswell. > Yes, I will revise it. > > + pins_state = pinctrl_lookup_state(fpc->pinctrl, > > + statename); > > + /* enable pins to be muxed in and configured */ > > + if (!IS_ERR(pins_state)) { > > + ret = pinctrl_select_state(fpc->pinctrl, pins_state); > > + if (ret) > > + dev_warn(chip->dev, "could not set default pins\n"); > > + } else > > + dev_warn(chip->dev, "could not get default pinstate\n"); > > Either it's ok to do without pinctrl or it's not ok, so either return an > error or drop the warnings. Polluting the kernel log with such messages > from a frequently called function is not a good idea. > Well, I will just print out some error logs and return the error. -- Best Regards. Xiubo -- 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/