From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4F43C433E6 for ; Fri, 28 Aug 2020 09:37:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C4EAD2075B for ; Fri, 28 Aug 2020 09:37:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="l9bHksVS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728876AbgH1Jh4 (ORCPT ); Fri, 28 Aug 2020 05:37:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728870AbgH1Jhy (ORCPT ); Fri, 28 Aug 2020 05:37:54 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61665C061264 for ; Fri, 28 Aug 2020 02:37:54 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id b79so305001wmb.4 for ; Fri, 28 Aug 2020 02:37:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=Bw/hJUCksUzdnYz1OV2HXr3nd3wIg7/5HBoKNMsU7YU=; b=l9bHksVSc3466fdG9auSnxZgvNILFVOMJ1JD4XkUzy2/snmm4w6CGGgsQ8aer64RR5 XRMTJa7zN7/aMkfzmRWeycIQOI+f9B8b6mOpmqnKWN4E177x0b2z+hiSY+BgH8vXLqIL URVBo7uIbqpigTS+JBP5hmly9B+FrIVMZOHN58pJtoMSltkOaVhLv6QaTkTMy7zEByY2 dWVnOjDJgsomEGP1OI4j2E+ECT6ne6P+Ef6hitG0L2Rhxk8eyVJMZJrKQFZ1lRid9+bT ZZCIhXiz+ZjfCnIphZUqu25tw/8Z1ct4/SRRTi+HzLOqMpkvdrSCHhZ9y+Gl6dgTYUu4 BAhA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=Bw/hJUCksUzdnYz1OV2HXr3nd3wIg7/5HBoKNMsU7YU=; b=b+SMcANPk3XnwFICBSFat2YTyok508EU1nWRHbbZenAgmaHaixCeyAU/FrASzjcoH4 dt5DMXop/bnuHpCjNMLbAjJ8nKKw0dRDYpRwjmXE6PXZ/5dvO4DZPVisEzaIU5obyxlD rr10tRGDH6Dl7sNPGez47W5UvI++j1dRYYTL6xnHuU/bE3RCvb6dqtlCzZKmq6SQBsai 6gjqBCcubdeKt/yiUUKymUgR6q0JrEARfeEuQFSz9tFsfMyqCIee1tXFOppzJ+zkyTQr UpbL5THOSbr/arAorSI/ITJe2W1k/UalHrZbjNjW2W1FJ/f2tbfHTPfTqq9UWzPpF1iU 3hOA== X-Gm-Message-State: AOAM530eY5URnQ9qXa271XtjMN/r9xpRErDBncP5y9dEE7BHkHYYGr55 Fj6lCBDzM7rIRq8R67ZlsLib2A== X-Google-Smtp-Source: ABdhPJxl5wmAWuFFGhxJGgDkhxBj3PbLL7k0DpkB7xh5nKEYgMTIb7wUBb3Akksqx+Yq1ttHLfhxQw== X-Received: by 2002:a7b:c925:: with SMTP id h5mr769066wml.28.1598607473006; Fri, 28 Aug 2020 02:37:53 -0700 (PDT) Received: from dell ([91.110.221.141]) by smtp.gmail.com with ESMTPSA id 21sm1152049wrc.55.2020.08.28.02.37.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Aug 2020 02:37:52 -0700 (PDT) Date: Fri, 28 Aug 2020 10:37:50 +0100 From: Lee Jones To: David Jander Cc: Steffen Trumtrar , Clemens Gruber , Thierry Reding , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , linux-pwm@vger.kernel.org, Oleksij Rempel Subject: Re: [PATCH] drivers: pwm: pwm-pca9685.c: Disable unused alternative addresses Message-ID: <20200828093750.GE1826686@dell> References: <20200820121358.729873-1-david@protonic.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200820121358.729873-1-david@protonic.nl> Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org On Thu, 20 Aug 2020, David Jander wrote: > The PCA9685 supports listening to 1 or more alternative I2C chip addresses > for some special features that this driver does not support. > By default the LED ALLCALL address is active (default 0x70), which causes > this chip to respond to address 0x70 in addition to its main address > (0x41). This is not desireable if there is another device on the same bus > that uses this address (like a TMP103 for example). > Since this feature is not supported by this driver, it is best to disable > these addresses in the chip to avoid unsuspecting bus collisions. Nit: s/unsuspecting/unsuspected/ "Those unsuspecting bus collisions didn't know what hit them!" > Signed-off-by: David Jander > --- > drivers/pwm/pwm-pca9685.c | 23 ++++++++++++++++------- > 1 file changed, 16 insertions(+), 7 deletions(-) > > diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c > index 76cd22bd6614..63ff1f22246d 100644 > --- a/drivers/pwm/pwm-pca9685.c > +++ b/drivers/pwm/pwm-pca9685.c > @@ -58,6 +58,10 @@ > #define PCA9685_MAXCHAN 0x10 > > #define LED_FULL (1 << 4) > +#define MODE1_ALLCALL (1 << 0) > +#define MODE1_SUB3 (1 << 1) > +#define MODE1_SUB2 (1 << 2) > +#define MODE1_SUB1 (1 << 3) > #define MODE1_SLEEP (1 << 4) > #define MODE2_INVRT (1 << 4) > #define MODE2_OUTDRV (1 << 2) Nit: Consider converting these to BIT() in a subsequent patch. > @@ -444,7 +448,7 @@ static int pca9685_pwm_probe(struct i2c_client *client, > { > struct pca9685 *pca; > int ret; > - int mode2; > + int reg; > > pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL); > if (!pca) > @@ -461,19 +465,24 @@ static int pca9685_pwm_probe(struct i2c_client *client, > > i2c_set_clientdata(client, pca); > > - regmap_read(pca->regmap, PCA9685_MODE2, &mode2); > + regmap_read(pca->regmap, PCA9685_MODE2, ®); > > if (device_property_read_bool(&client->dev, "invert")) > - mode2 |= MODE2_INVRT; > + reg |= MODE2_INVRT; > else > - mode2 &= ~MODE2_INVRT; > + reg &= ~MODE2_INVRT; > > if (device_property_read_bool(&client->dev, "open-drain")) > - mode2 &= ~MODE2_OUTDRV; > + reg &= ~MODE2_OUTDRV; > else > - mode2 |= MODE2_OUTDRV; > + reg |= MODE2_OUTDRV; > > - regmap_write(pca->regmap, PCA9685_MODE2, mode2); > + regmap_write(pca->regmap, PCA9685_MODE2, reg); > + > + /* Disable all LED ALLCALL and SUBx addresses to avoid bus collisions */ > + regmap_read(pca->regmap, PCA9685_MODE1, ®); > + reg &= ~(MODE1_ALLCALL | MODE1_SUB1 | MODE1_SUB2 | MODE1_SUB3); > + regmap_write(pca->regmap, PCA9685_MODE1, reg); > > /* clear all "full off" bits */ Nit: Consider drafting a patch to make commenting more consistent in this file. I suggest always starting with an uppercase char. > regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0); The patch itself is generally okay though: Acked-by: Lee Jones -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog