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=-15.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 62D16C2B9F2 for ; Sat, 22 May 2021 13:41:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2957C60C41 for ; Sat, 22 May 2021 13:41:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230484AbhEVNnB (ORCPT ); Sat, 22 May 2021 09:43:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230472AbhEVNnA (ORCPT ); Sat, 22 May 2021 09:43:00 -0400 Received: from mail-oo1-xc34.google.com (mail-oo1-xc34.google.com [IPv6:2607:f8b0:4864:20::c34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41A55C061574; Sat, 22 May 2021 06:41:35 -0700 (PDT) Received: by mail-oo1-xc34.google.com with SMTP id i8-20020a4aa1080000b0290201edd785e7so5237706ool.1; Sat, 22 May 2021 06:41:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:to:references:from:subject:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=6q8b1N4MxU8JhrPvdZs1GsjYLUNjhqrng5So4JodxJc=; b=s4J31AQDxIfkUDrXCTiZJClwfIXFmxjXh5NWzVM2vm+vsZBywqa30tWoKTY7I9swID qGT21w/c/JbuW/OikBh+vOh/Db5csjuLSg1upgu5cZ57Q6/5xb1EHuFhZu8NyM3BqAcg poZCHmtoOgDxdPWrVhF7LNn0NoOZTZJPnYVlgACWKtivuKAVuZTabYTjwp8VGDiaV2YQ OoTRh++SZK8PQ0awpNcMEv6ix2vSTvmieDuHIHB3qX9vDnsURIDuApoenVe34U36jVdg ViYGZHJ3qQHJDrnVuuouQHNbTw2xmZSwzO30X7LmlSQaByXmdPk1tGiEyQ1zZUpjolOL C4wg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:to:references:from:subject:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=6q8b1N4MxU8JhrPvdZs1GsjYLUNjhqrng5So4JodxJc=; b=pw7zO24WlmUBe1Qrm+6GhGvIBdGPcmwCYawIFyXBxDsaYROccJ8lD2xOeAIOXBOnKL 7slpWFsaMf/EhtairYP8idrzze/w/miBEy+kvB6Qf8sQgf79l9woXDEae9mK34xQsw0O fL5x8oS/1Yw0i0tJMKpaADChSG9hx26zgKt7AAcMhMUOhJ4QpWjovlJ3IBqttx21zx3e HlCRPGVvr5DYsjjaFCAerCC+Av8vucs+bdAYDAnhkDSKiS4GQVVObBReCz6YtKh7S4M5 oxEuRheqhCaRDhyaecYquYPYWFiX2CbXd1n8m8rNLH+QQ7QA6rielnFFMRMyBpfq+U0V MNNg== X-Gm-Message-State: AOAM533fEl4LzUndncyzLHLHg74qKIqI8S4vCUckqKxQ/O+iJDraSGTp W07TuDGxBATe73Y3hcQjrW+PuMhz+tE= X-Google-Smtp-Source: ABdhPJyjpHx6voET46fAH6m5fZRnU7WXKwfKKro8RpIUVCcIKyM3F7kGLQIbUWhv/XrdF1jBJC+HZA== X-Received: by 2002:a4a:dd99:: with SMTP id h25mr3364272oov.63.1621690893825; Sat, 22 May 2021 06:41:33 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id h59sm1860042otb.29.2021.05.22.06.41.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 22 May 2021 06:41:33 -0700 (PDT) Sender: Guenter Roeck To: Erik Rosen , Jean Delvare , Jonathan Corbet , linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210522105528.87629-1-erik.rosen@metormote.com> <20210522105528.87629-4-erik.rosen@metormote.com> From: Guenter Roeck Subject: Re: [PATCH v2 3/6] hwmon: (pmbus/pim4328) Add support for reading direct format coefficients Message-ID: <24ff79b6-29f5-6921-7418-9ba93bcf7193@roeck-us.net> Date: Sat, 22 May 2021 06:41:31 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210522105528.87629-4-erik.rosen@metormote.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org On 5/22/21 3:55 AM, Erik Rosen wrote: > Add support for reading and decoding direct format coefficients to > the PMBus core driver. If the new flag PMBUS_USE_COEFFICIENTS_CMD > is set, the driver will use the COEFFICIENTS register together with > the information in the pmbus_sensor_attr structs to initialize > relevant coefficients for the direct mode format. > > Signed-off-by: Erik Rosen > --- > drivers/hwmon/pmbus/pmbus_core.c | 93 ++++++++++++++++++++++++++++++++ > include/linux/pmbus.h | 8 +++ > 2 files changed, 101 insertions(+) > > diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c > index 460cbfd716e4..03c169bf5633 100644 > --- a/drivers/hwmon/pmbus/pmbus_core.c > +++ b/drivers/hwmon/pmbus/pmbus_core.c > @@ -2177,6 +2177,38 @@ static int pmbus_find_attributes(struct i2c_client *client, > return ret; > } > > +static int pmbus_init_coefficients(struct i2c_client *client, > + struct pmbus_data *data, int page, This seems wrong. Coefficients are not maintained per page but per class, and (re-)reading them for each supported page doesn't really add value or even make sense. > + enum pmbus_sensor_classes sensor_class, > + const struct pmbus_sensor_attr *attrs, > + int nattrs) > +{ > + int i, status; > + > + for (i = 0; i < nattrs; i++) { > + if (attrs->class == sensor_class && > + (attrs->func & data->info->func[page])) { > + status = pmbus_read_coefficients(client, > + (struct pmbus_driver_info *)data->info, > + sensor_class, > + attrs->reg); > + if (status < 0) { > + dev_err(&client->dev, > + "Failed to read coefficients for register: %x\n", > + attrs->reg); > + return status; > + } > + return 0; > + } > + attrs++; > + } > + > + dev_err(&client->dev, "No coefficients found for register: %x\n", > + attrs->reg); > + attrs points beyond the array size here, so attrs->reg does not point to a valid array element. The problem would also not be the register this happens to point to, but the class (ie the chip does not support a sensor of the requested class). Not sure if this should trigger a message or error in the first place. It won't matter since the chip will never need those coefficients. If anything, this would be a misconfiguration (the driver should not set direct format for this sensor class), and the return value should be -EINVAL. Either case, I wonder if this can be handled with less complex code, ie without having to check data->info->func[] for all pages. How about just walking through attrs and try all class matches until one is found that works (ie not return on error but keep trying) ? > + return -ENODEV; > +} > + > /* > * Identify chip parameters. > * This function is called for all chips. > @@ -2185,6 +2217,7 @@ static int pmbus_identify_common(struct i2c_client *client, > struct pmbus_data *data, int page) > { > int vout_mode = -1; > + int ret; > > if (pmbus_check_byte_register(client, page, PMBUS_VOUT_MODE)) > vout_mode = _pmbus_read_byte_data(client, page, > @@ -2214,6 +2247,66 @@ static int pmbus_identify_common(struct i2c_client *client, > } > } > > + if (data->flags & PMBUS_USE_COEFFICIENTS_CMD) { I think there should be a separate function to handle that, to be called only once, not once per page. > + if (!i2c_check_functionality(client->adapter, > + I2C_FUNC_SMBUS_BLOCK_PROC_CALL)) > + return -ENODEV; > + > + if (data->info->format[PSC_VOLTAGE_IN] == direct) { > + ret = pmbus_init_coefficients(client, data, page, > + PSC_VOLTAGE_IN, > + voltage_attributes, > + ARRAY_SIZE(voltage_attributes)); > + if (ret) > + return ret; > + } It might be useful to have a little structure with {class, attribute list pointer, attribute list size} and walk through that in a loop instead of repeating essentially the same code multiple times. > + > + if (data->info->format[PSC_VOLTAGE_OUT] == direct) { > + ret = pmbus_init_coefficients(client, data, page, > + PSC_VOLTAGE_OUT, > + voltage_attributes, > + ARRAY_SIZE(voltage_attributes)); > + if (ret) > + return ret; > + } > + > + if (data->info->format[PSC_CURRENT_IN] == direct) { > + ret = pmbus_init_coefficients(client, data, page, > + PSC_CURRENT_IN, > + current_attributes, > + ARRAY_SIZE(current_attributes)); > + if (ret) > + return ret; > + } > + > + if (data->info->format[PSC_CURRENT_OUT] == direct) { > + ret = pmbus_init_coefficients(client, data, page, > + PSC_CURRENT_OUT, > + current_attributes, > + ARRAY_SIZE(current_attributes)); > + if (ret) > + return ret; > + } > + > + if (data->info->format[PSC_POWER] == direct) { > + ret = pmbus_init_coefficients(client, data, page, > + PSC_POWER, > + power_attributes, > + ARRAY_SIZE(power_attributes)); > + if (ret) > + return ret; > + } > + > + if (data->info->format[PSC_TEMPERATURE] == direct) { > + ret = pmbus_init_coefficients(client, data, page, > + PSC_TEMPERATURE, > + temp_attributes, > + ARRAY_SIZE(temp_attributes)); > + if (ret) > + return ret; > + } > + } > + > pmbus_clear_fault_page(client, page); > return 0; > } > diff --git a/include/linux/pmbus.h b/include/linux/pmbus.h > index f720470b1bab..7fdc282dab5a 100644 > --- a/include/linux/pmbus.h > +++ b/include/linux/pmbus.h > @@ -52,6 +52,14 @@ > */ > #define PMBUS_NO_WRITE_PROTECT BIT(4) > > +/* > + * PMBUS_USE_COEFFICIENTS_CMD > + * > + * When this flag is set the PMBus core driver will use the COEFFICIENTS > + * register to initialize the coefficients for the direct mode format. > + */ > +#define PMBUS_USE_COEFFICIENTS_CMD BIT(5) > + > struct pmbus_platform_data { > u32 flags; /* Device specific flags */ > >