From patchwork Wed Sep 30 07:13:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tali Perry X-Patchwork-Id: 1374169 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4C1SGP1yzdz9sSf for ; Wed, 30 Sep 2020 17:15:57 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=gmail.com Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4C1SGN2XFVzDqXl for ; Wed, 30 Sep 2020 17:15:56 +1000 (AEST) X-Original-To: openbmc@lists.ozlabs.org Delivered-To: openbmc@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=nuvoton.com (client-ip=212.199.177.27; helo=herzl.nuvoton.co.il; envelope-from=tali.perry@nuvoton.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=fail (p=none dis=none) header.from=gmail.com Received: from herzl.nuvoton.co.il (212.199.177.27.static.012.net.il [212.199.177.27]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4C1SF465gyzDqDG for ; Wed, 30 Sep 2020 17:14:44 +1000 (AEST) 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 08U7DuH7016068; Wed, 30 Sep 2020 10:13:56 +0300 Received: by taln60.nuvoton.co.il (Postfix, from userid 20088) id D7798639D5; Wed, 30 Sep 2020 10:13:55 +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 Subject: [PATCH v1] i2c: npcm7xx: Support changing bus speed using debugfs. Date: Wed, 30 Sep 2020 10:13:42 +0300 Message-Id: <20200930071342.98691-1-tali.perry1@gmail.com> X-Mailer: git-send-email 2.22.0 MIME-Version: 1.0 X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: openbmc@lists.ozlabs.org, Tali Perry , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Errors-To: openbmc-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "openbmc" Systems that can dinamically add and remove slave devices often need to change the bus speed in runtime. This patch exposes the bus frequency to the user. This feature can also be used for test automation. Fixes: 56a1485b102e (i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver) Signed-off-by: Tali Perry --- drivers/i2c/busses/i2c-npcm7xx.c | 36 ++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) base-commit: 06d56c38d7d411c162e4d406a9864bed32e30e61 diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c index 2ad166355ec9..44e2340c1893 100644 --- a/drivers/i2c/busses/i2c-npcm7xx.c +++ b/drivers/i2c/busses/i2c-npcm7xx.c @@ -2208,6 +2208,41 @@ 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 = (u64)bus->bus_freq; + return 0; +} + +static int i2c_speed_set(void *data, u64 val) +{ + struct npcm_i2c *bus = data; + int ret; + + if (val < (u64)I2C_FREQ_MIN_HZ || val > (u64)I2C_FREQ_MAX_HZ) + return -EINVAL; + + if (val == (u64)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, "%lld\n"); + static void npcm_i2c_init_debugfs(struct platform_device *pdev, struct npcm_i2c *bus) { @@ -2223,6 +2258,7 @@ 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; }