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=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B0DC6C433E0 for ; Wed, 24 Jun 2020 21:28:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A767207FC for ; Wed, 24 Jun 2020 21:28:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="eeh0OUFG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403840AbgFXV2V (ORCPT ); Wed, 24 Jun 2020 17:28:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403837AbgFXV2V (ORCPT ); Wed, 24 Jun 2020 17:28:21 -0400 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C981CC061573; Wed, 24 Jun 2020 14:28:20 -0700 (PDT) Received: by mail-pf1-x443.google.com with SMTP id u5so1825868pfn.7; Wed, 24 Jun 2020 14:28:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=ZQxYRtrdi9vMsm5/HU8dIzNpM/BIdYP813BZZqvCjg0=; b=eeh0OUFGL1szB4i5Su7T59EnhhWG8V4dnvFfAmXwesd39jBEk1e5aJgu6jLpCvibqR lrDvI83l3+BoneNtxiWzBbWW/w7nIJfZ91hBWtMKoVGK2SIMc7vzfDKERDp1O72Zqpb1 SAznuYITDSjcYHM9yVCk7+6GU+dqic8dbw/5h2/aSIPpN/yPyMuw3jlQHAURBHi9pe0U A9blCDohZsgC95jEKcdmPGBn7Y+R7qN8cQts/CyrgGNWTTMLftGZhJywH9r5+md6xEk4 qLW5bsR1zhwq04slrMF72XhuDYcVUDd7ldUAUX7bdbO/hJZLe16c4tli0YrDTxxWAG68 xUXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=ZQxYRtrdi9vMsm5/HU8dIzNpM/BIdYP813BZZqvCjg0=; b=Ws+Y+Ov+vaZuduSd6F8X9NM4DBat4rMcedp1/SU2UqPZ1ZxTtMBExHaNpEJuLLER9v RDtVkdNDpakdJTMwoAstA7BSTeTC0JWbvahQCs7JqB7gr6974oPZCj9ivGEqq6tgDMuq 5RGU9cxD/NdvGd5eXqWK1q8FbTAfXVFqfXpa9Gnd2HQB4mE9BFcux5sKSihc2dMRgKQf QVGJgONbYEqFhOYl4Ceacnuq1hsQXhmLy6pnEuxGMLSIb1cDEthlFOoOmnxQl0vWZ9oy CseIiB5TnbZbHkFo4FRk95UAErw87wnUirMftaRpNcUUcdrTyoCI3CZkiqGue/miFdwZ CdSg== X-Gm-Message-State: AOAM532xch8Mp++ES4nlmgMfSjSG+qvk2PsJb5SOl6Fq41/PFKlqayJZ l4XaCpfbD1XrnskdbZsK7kA= X-Google-Smtp-Source: ABdhPJwOtNYzpuiQLvOOi783XQ5IsW5kFW5cCx0iaESxphTAfmmd9rqiD8gUnZXdENB+Ac1a24XG9Q== X-Received: by 2002:aa7:8d07:: with SMTP id j7mr978970pfe.125.1593034100358; Wed, 24 Jun 2020 14:28:20 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id j16sm217410pfr.100.2020.06.24.14.28.19 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Wed, 24 Jun 2020 14:28:19 -0700 (PDT) Date: Wed, 24 Jun 2020 14:28:18 -0700 From: Guenter Roeck To: alexandru.tachici@analog.com Cc: linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, robh+dt@kernel.org Subject: Re: [PATCH v4 2/7] hwmon: pmbus: adm1266: Add Block process call Message-ID: <20200624212818.GA74031@roeck-us.net> References: <20200623173659.41358-1-alexandru.tachici@analog.com> <20200623173659.41358-3-alexandru.tachici@analog.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200623173659.41358-3-alexandru.tachici@analog.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org On Tue, Jun 23, 2020 at 08:36:54PM +0300, alexandru.tachici@analog.com wrote: > From: Alexandru Tachici > > PmBus devices support Block Write-Block Read Process > Call described in SMBus specification v 2.0 with the > exception that Block writes and reads are permitted to > have up 255 data bytes instead of max 32 bytes (SMBus). > > This patch adds Block WR process call support for ADM1266. > > Signed-off-by: Alexandru Tachici > --- > drivers/hwmon/pmbus/Kconfig | 1 + > drivers/hwmon/pmbus/adm1266.c | 79 +++++++++++++++++++++++++++++++++++ > 2 files changed, 80 insertions(+) > > diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig > index 6949483aa732..dc6971a7c49e 100644 > --- a/drivers/hwmon/pmbus/Kconfig > +++ b/drivers/hwmon/pmbus/Kconfig > @@ -28,6 +28,7 @@ config SENSORS_PMBUS > > config SENSORS_ADM1266 > tristate "Analog Devices ADM1266 Sequencer" > + select CRC8 > help > If you say yes here you get hardware monitoring support for Analog > Devices ADM1266 Cascadable Super Sequencer. > diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c > index a7ef048a9a5c..381d89a8569f 100644 > --- a/drivers/hwmon/pmbus/adm1266.c > +++ b/drivers/hwmon/pmbus/adm1266.c > @@ -6,6 +6,7 @@ > * Copyright 2020 Analog Devices Inc. > */ > > +#include > #include > #include > #include > @@ -14,6 +15,82 @@ > > #include "pmbus.h" > > +#define ADM1266_PMBUS_BLOCK_MAX 255 > + > +DECLARE_CRC8_TABLE(pmbus_crc_table); > + > +/* Different from Block Read as it sends data and waits for the slave to /* * Proper multi-line comment */ > + * return a value dependent on that data. The protocol is simply a Write Block > + * followed by a Read Block without the Read-Block command field and the > + * Write-Block STOP bit. > + */ static > +int pmbus_block_xfer(struct i2c_client *client, u8 cmd, u8 w_len, > + u8 *data_w, u8 *data_r) > +{ > + u8 write_buf[ADM1266_PMBUS_BLOCK_MAX + 2]; > + struct i2c_msg msgs[2] = { > + { > + .addr = client->addr, > + .flags = 0, > + .buf = write_buf, > + .len = w_len + 2, > + }, > + { > + .addr = client->addr, > + .flags = I2C_M_RD, > + .len = ADM1266_PMBUS_BLOCK_MAX + 2, > + } > + }; > + u8 addr = 0; > + u8 crc = 0; Unnecessary initialization for both variables > + int ret; > + > + msgs[0].buf[0] = cmd; > + msgs[0].buf[1] = w_len; > + memcpy(&msgs[0].buf[2], data_w, w_len); > + > + msgs[0].buf = i2c_get_dma_safe_msg_buf(&msgs[0], 1); > + if (!msgs[0].buf) > + return -ENOMEM; > + > + msgs[1].buf = i2c_get_dma_safe_msg_buf(&msgs[1], 1); > + if (!msgs[1].buf) { > + i2c_put_dma_safe_msg_buf(msgs[0].buf, &msgs[0], false); > + return -ENOMEM; > + } AFAICS i2c_get_dma_safe_msg_buf() is supposed to be used by i2c bus drivers, not by device drivers. If this is needed for the target architecture, it should be implemented in the bus driver, not here. > + > + ret = i2c_transfer(client->adapter, msgs, 2); > + if (ret != 2) { > + ret = -EPROTO; Should retain error if ret < 0, and only return EPROTO if the return value is 0 or 1. > + goto cleanup; > + } > + > + if (client->flags & I2C_CLIENT_PEC) { > + addr = i2c_8bit_addr_from_msg(&msgs[0]); > + crc = crc8(pmbus_crc_table, &addr, 1, crc); > + crc = crc8(pmbus_crc_table, msgs[0].buf, msgs[0].len, crc); > + > + addr = i2c_8bit_addr_from_msg(&msgs[1]); > + crc = crc8(pmbus_crc_table, &addr, 1, crc); > + crc = crc8(pmbus_crc_table, msgs[1].buf, msgs[1].buf[0] + 1, > + crc); > + > + if (crc != msgs[1].buf[msgs[1].buf[0] + 1]) { > + ret = -EBADMSG; > + goto cleanup; > + } > + } > + > + memcpy(data_r, &msgs[1].buf[1], msgs[1].buf[0]); > + ret = msgs[1].buf[0]; > + > +cleanup: > + i2c_put_dma_safe_msg_buf(msgs[0].buf, &msgs[0], true); > + i2c_put_dma_safe_msg_buf(msgs[1].buf, &msgs[1], true); > + > + return ret; > +} > + > static int adm1266_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > @@ -24,6 +101,8 @@ static int adm1266_probe(struct i2c_client *client, > info = devm_kzalloc(&client->dev, sizeof(struct pmbus_driver_info), > GFP_KERNEL); > > + crc8_populate_msb(pmbus_crc_table, 0x7); > + > info->pages = 17; > info->format[PSC_VOLTAGE_OUT] = linear; > funcs = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT;