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=-17.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, 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,USER_IN_DEF_DKIM_WL 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 E4263C433DF for ; Wed, 14 Oct 2020 09:21:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D09820B1F for ; Wed, 14 Oct 2020 09:21:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="nY30yW+W" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387781AbgJNJVE (ORCPT ); Wed, 14 Oct 2020 05:21:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731095AbgJNJUn (ORCPT ); Wed, 14 Oct 2020 05:20:43 -0400 Received: from mail-ot1-x342.google.com (mail-ot1-x342.google.com [IPv6:2607:f8b0:4864:20::342]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D6E3C0613E2 for ; Tue, 13 Oct 2020 14:29:23 -0700 (PDT) Received: by mail-ot1-x342.google.com with SMTP id m13so1461913otl.9 for ; Tue, 13 Oct 2020 14:29:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=BQVUP6sy3PX6Q3C2BLkQ+7wHeBtTeqDYnlZeUE9CcjA=; b=nY30yW+WJ9MyaUbcO1v/mKwFDXq94hxYfbWo/1L56jEnYbDaOUoYy9nIdcUT28q/3c Uq9y09kxs8N4qWd/Ff1kdavb8TyIc6oBlU3oviAsPjgw5zqHaKMjWs85k6EGx1lxqE03 VQTguqayk1ztH//dzkEuTPpRd/rbKtMe5TYkZHhAmRaVfWU6khywIlm/eXZEB8R3YU/t RvblJocOk1w4YKITaedGGSW+l4IlsJxZKuoRhJl4WWr78Rm5iE0CXNAtN8R0QHvYHTcS E2nLmPwqNzyIxnEb9m2N39CFYlvmttezElfEknCVV0scF33M9yCSq3OfXIi84EC3hOJ5 U74Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=BQVUP6sy3PX6Q3C2BLkQ+7wHeBtTeqDYnlZeUE9CcjA=; b=g1tvUFFmFQN4XnFkQkPTMSpcygomvIlASWvohH91xSG455G5S7UBLBLE1V4mbwhcuc KnF58sjho00ooalWoTHSl4UW1XuhsRn5UuWWn5j4yY1b7CeOiTuMyh6aXpx9lIXeozfi T7r7XlwjsDP9aBT08X9PuOX3kbdcila/hvmlC1oN/83UP+cxrCcKn0iGN+9ger6kouED vPSFY3Rvt9aDsX/Gsy+ylTi6VrHPfRUXZJ1/glzvGdidZL5fHhw1UJYc7YfISNInOkOW 8VINZVBo84JuRtUNt2AknbZ9UxuBJj6D8C3p4xM5zQUfZ4c9kg8jMG4zijXPlbqwItNZ Gn8Q== X-Gm-Message-State: AOAM531dwMCNDGEQIfvnhSUpnVTj9INxEugp/4g6aWXtHmTd5tzhFPd0 v5pLAZ/jKo0YR9diluJdHLxBcaYsHV6AHln/9RPYZw== X-Google-Smtp-Source: ABdhPJyWjnabEyver0ZLJs3j3vpJ6dQJC3dFlcNQoNysjkLGxpSekou/SW+1ozZsc27Ff8tuKWkk2Jcm4I0Yp/Rrics= X-Received: by 2002:a9d:7b59:: with SMTP id f25mr1167062oto.306.1602624562402; Tue, 13 Oct 2020 14:29:22 -0700 (PDT) MIME-Version: 1.0 References: <20201013100314.216154-1-tali.perry1@gmail.com> <20201013115023.GL4077@smile.fi.intel.com> In-Reply-To: <20201013115023.GL4077@smile.fi.intel.com> From: Alex Qiu Date: Tue, 13 Oct 2020 14:29:11 -0700 Message-ID: Subject: Re: [PATCH v2] i2c: npcm7xx: Support changing bus speed using debugfs. To: Andy Shevchenko Cc: Tali Perry , Wolfram Sang , Kun Yi , Benjamin Fair , Avi Fishman , Joel Stanley , Tomer Maimon , Linux I2C , OpenBMC Maillist , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Tested again, and the updated patch is still working. On Tue, Oct 13, 2020 at 4:49 AM Andy Shevchenko wrote: > > On Tue, Oct 13, 2020 at 01:03:14PM +0300, Tali Perry wrote: > > Systems that can dynamically add and remove slave devices > > often need to change the bus speed in runtime. > > This patch expose the bus frequency to the user. > > This feature can also be used for test automation. > > > -- > > v2 -> v1: > > - Fix typos. > > - Remove casting to u64. > > > > v1: initial version > > Above block should go after cutter '---' (see below) line... > > > Fixes: 56a1485b102e (i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver) > > Signed-off-by: Tali Perry Reviewed-by: Alex Qiu Tested-by: Alex Qiu > > --- > > ...here. > > > drivers/i2c/busses/i2c-npcm7xx.c | 35 ++++++++++++++++++++++++++++++++ > > 1 file changed, 35 insertions(+) > > As we discussed previously I'm not a fan of the functionality this gives and a > way it's done, but this is debugfs and not anyhow an ABI. Also it's localized > inside one driver. In the future we may come up with better approach. > > That said, no objections from me. > > > diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c > > index 2ad166355ec9..633ac67153e2 100644 > > --- a/drivers/i2c/busses/i2c-npcm7xx.c > > +++ b/drivers/i2c/busses/i2c-npcm7xx.c > > @@ -2208,6 +2208,40 @@ static const struct i2c_algorithm npcm_i2c_algo = { > > /* i2c debugfs directory: used to keep health monitor of i2c devices */ > > static struct dentry *npcm_i2c_debugfs_dir; > > > > +static int i2c_speed_get(void *data, u64 *val) > > +{ > > + struct npcm_i2c *bus = data; > > + > > + *val = bus->bus_freq; > > + return 0; > > +} > > + > > +static int i2c_speed_set(void *data, u64 val) > > +{ > > + struct npcm_i2c *bus = data; > > + int ret; > > + > > + if (val < I2C_FREQ_MIN_HZ || val > I2C_FREQ_MAX_HZ) > > + return -EINVAL; > > + > > + if (val == bus->bus_freq) > > + return 0; > > + > > + i2c_lock_bus(&bus->adap, I2C_LOCK_ROOT_ADAPTER); > > + > > + npcm_i2c_int_enable(bus, false); > > + > > + ret = npcm_i2c_init_module(bus, I2C_MASTER, (u32)val); > > + > > + i2c_unlock_bus(&bus->adap, I2C_LOCK_ROOT_ADAPTER); > > + > > + if (ret) > > + return -EAGAIN; > > + > > + return 0; > > +} > > +DEFINE_DEBUGFS_ATTRIBUTE(i2c_clock_ops, i2c_speed_get, i2c_speed_set, "%llu\n"); > > + > > static void npcm_i2c_init_debugfs(struct platform_device *pdev, > > struct npcm_i2c *bus) > > { > > @@ -2223,6 +2257,7 @@ static void npcm_i2c_init_debugfs(struct platform_device *pdev, > > debugfs_create_u64("rec_succ_cnt", 0444, d, &bus->rec_succ_cnt); > > debugfs_create_u64("rec_fail_cnt", 0444, d, &bus->rec_fail_cnt); > > debugfs_create_u64("timeout_cnt", 0444, d, &bus->timeout_cnt); > > + debugfs_create_file("i2c_speed", 0644, d, bus, &i2c_clock_ops); > > > > bus->debugfs = d; > > } > > > > base-commit: 865c50e1d279671728c2936cb7680eb89355eeea > > -- > > 2.22.0 > > > > -- > With Best Regards, > Andy Shevchenko > > - Alex Qiu