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, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 5BB3AC433DF for ; Tue, 13 Oct 2020 11:49:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03EDB214DB for ; Tue, 13 Oct 2020 11:49:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727148AbgJMLt1 (ORCPT ); Tue, 13 Oct 2020 07:49:27 -0400 Received: from mga05.intel.com ([192.55.52.43]:12818 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726388AbgJMLt0 (ORCPT ); Tue, 13 Oct 2020 07:49:26 -0400 IronPort-SDR: GIR88rKzu6XEi2xkA/TcSAv4EI3xrX9CusWWQCt+mL3VpGCod2OzSu6cZnJW9TSgoWTnU3Jm9W n0SFYCyivB6g== X-IronPort-AV: E=McAfee;i="6000,8403,9772"; a="250589292" X-IronPort-AV: E=Sophos;i="5.77,370,1596524400"; d="scan'208";a="250589292" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2020 04:49:25 -0700 IronPort-SDR: fKI1CIVL3TQGd0i33Ir236iwYH6hYmucZP/YzxKQuSuYVNcZs5we04sss9kdiEzuaA2shv9ihM IHGwFF2cH4Gg== X-IronPort-AV: E=Sophos;i="5.77,370,1596524400"; d="scan'208";a="313770836" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2020 04:49:21 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1kSIox-005n54-Sf; Tue, 13 Oct 2020 14:50:23 +0300 Date: Tue, 13 Oct 2020 14:50:23 +0300 From: Andy Shevchenko To: Tali Perry Cc: wsa@kernel.org, xqiu@google.com, kunyi@google.com, benjaminfair@google.com, avifishman70@gmail.com, joel@jms.id.au, tmaimon77@gmail.com, linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] i2c: npcm7xx: Support changing bus speed using debugfs. Message-ID: <20201013115023.GL4077@smile.fi.intel.com> References: <20201013100314.216154-1-tali.perry1@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201013100314.216154-1-tali.perry1@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org 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 > --- ...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