From patchwork Tue Oct 13 10:03:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tali Perry X-Patchwork-Id: 269628 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=-12.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 34DF3C433DF for ; Tue, 13 Oct 2020 10:05:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B09F6207C3 for ; Tue, 13 Oct 2020 10:05:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726501AbgJMKFd (ORCPT ); Tue, 13 Oct 2020 06:05:33 -0400 Received: from 212.199.177.27.static.012.net.il ([212.199.177.27]:57528 "EHLO herzl.nuvoton.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726495AbgJMKFd (ORCPT ); Tue, 13 Oct 2020 06:05:33 -0400 Received: from taln60.nuvoton.co.il (ntil-fw [212.199.177.25]) by herzl.nuvoton.co.il (8.13.8/8.13.8) with ESMTP id 09DA3P1A022735; Tue, 13 Oct 2020 13:03:25 +0300 Received: by taln60.nuvoton.co.il (Postfix, from userid 20088) id 533D8639D6; Tue, 13 Oct 2020 13:03:25 +0300 (IDT) From: Tali Perry To: wsa@kernel.org, andriy.shevchenko@linux.intel.com, xqiu@google.com, kunyi@google.com, benjaminfair@google.com, avifishman70@gmail.com, joel@jms.id.au, tmaimon77@gmail.com Cc: linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org, Tali Perry Subject: [PATCH v2] i2c: npcm7xx: Support changing bus speed using debugfs. Date: Tue, 13 Oct 2020 13:03:14 +0300 Message-Id: <20201013100314.216154-1-tali.perry1@gmail.com> X-Mailer: git-send-email 2.22.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org 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. Reviewed-by: Alex Qiu Tested-by: Alex Qiu Reviewed-by: Joel Stanley --- v2 -> v1: - Fix typos. - Remove casting to u64. v1: initial version Fixes: 56a1485b102e (i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver) Signed-off-by: Tali Perry --- drivers/i2c/busses/i2c-npcm7xx.c | 35 ++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) base-commit: 865c50e1d279671728c2936cb7680eb89355eeea 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; }