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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3AC7C433FE for ; Wed, 13 Oct 2021 17:20:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD5B261040 for ; Wed, 13 Oct 2021 17:20:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237598AbhJMRWw (ORCPT ); Wed, 13 Oct 2021 13:22:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34058 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230232AbhJMRWt (ORCPT ); Wed, 13 Oct 2021 13:22:49 -0400 Received: from mail-lf1-x12a.google.com (mail-lf1-x12a.google.com [IPv6:2a00:1450:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34A42C061570 for ; Wed, 13 Oct 2021 10:20:45 -0700 (PDT) Received: by mail-lf1-x12a.google.com with SMTP id x27so15156661lfu.5 for ; Wed, 13 Oct 2021 10:20:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=4zZUExOF0hyjkUuayvESFrp0hpOC5bsezzAMG365TXc=; b=jVHe5if0odQ3h3gs6Lq/533GPpFM71VvqJKxpmxEyuRr/I2s4Rvysokvg9L+KV3dn3 jRKt3VHl/ZpEYDkM/BH/iek34kzKyj4veqxzh8fQGB17xK/+O3hgNFd0wfiFi8GJFL8O XGKIWscpPGckGAX2Xs2zotyUIBtmLVnQQZxEHyl7jUZCT2eoumnG9hdqBAbXwcV9VkC7 YVsKq97QPiDiZSw+I05pO7hVnS5lfOb4LpMGX3WBNKgTvYqcquezqMk82nwjo1T41Nwt 1fuMFta0MEDU+HsQuN1GGsxD+iaSbNXX+P38mduPvBswEpDmrnRsnBKN0spRJLnFFzf2 iqIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=4zZUExOF0hyjkUuayvESFrp0hpOC5bsezzAMG365TXc=; b=h8882qJHqOnbcc3OQE+arJfFxwqhTfnxC+8KzEui4UPZPXmVlCLD2zsFGkdDztIhaE B7bkRYEonn4VKR181KyCF176tIYE9cGrBfnInjub4LHwfbqNkeYfGF8eOuEW8BHVQuod PERXzowe4aT2OGIsKvJlnYm8Ex0U+VKTMN6tfOqgg5wDrE03pHrE6rAfGYTF3FSwudwS xkZ4hcug64WnJLFUTm2JyX2B1ZvdBzms3EcDFK3vfFaLP8VUESFg4OubdZnQK/tsrVeH NhKdLighh9+QCTYLXQE4vX+zIvTpMq3KbX8yTj7yMtlJiPulmLtm0ZF/F7DfD/nIJeYA BqTg== X-Gm-Message-State: AOAM530tkWlz2xAhb1/pr943PTVLxKjIPtYLWsKvb6frBRBo/fJKRsnJ A2XvGOYVIpFxm7OwvlWXv/Hqug== X-Google-Smtp-Source: ABdhPJwG8jkIxBjdv4FCfNEF54htx9eOR1dcNl/kyZV/O8USH10MekCsQswhdunIml07aX7jFJEXlA== X-Received: by 2002:a05:651c:1693:: with SMTP id bd19mr613631ljb.409.1634145643483; Wed, 13 Oct 2021 10:20:43 -0700 (PDT) Received: from localhost ([31.134.121.151]) by smtp.gmail.com with ESMTPSA id c3sm13525ljh.58.2021.10.13.10.20.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Oct 2021 10:20:43 -0700 (PDT) From: Sam Protsenko To: Michael Turquette , Stephen Boyd , Russell King Cc: Chanwoo Choi , Sylwester Nawrocki , Krzysztof Kozlowski , Mike Tipton , Andy Shevchenko , Andy Shevchenko , Geert Uytterhoeven , Fabio Estevam , linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v6] clk: Add write operation for clk_parent debugfs node Date: Wed, 13 Oct 2021 20:20:42 +0300 Message-Id: <20211013172042.10884-1-semen.protsenko@linaro.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Useful for testing mux clocks. One can write the index of the parent to be set into clk_parent node, starting from 0. Example # cd /sys/kernel/debug/clk/mout_peri_bus # cat clk_possible_parents dout_shared0_div4 dout_shared1_div4 # cat clk_parent dout_shared0_div4 # echo 1 > clk_parent # cat clk_parent dout_shared1_div4 CLOCK_ALLOW_WRITE_DEBUGFS has to be defined in drivers/clk/clk.c in order to use this feature. Signed-off-by: Sam Protsenko Reviewed-by: Andy Shevchenko Reviewed-by: Geert Uytterhoeven --- Changes in v6: - Added R-b tag by Geert Uytterhoeven - Removed curly braces around 'else' block (now delta is minimal and the code looks better) Changes in v5: - Used kstrtou8_from_user() API - Got rid of code duplication - Fixed typo in commit message - Added R-b tag by Andy Shevchenko Changes in v4: - Fixed the commit title Changes in v3: - Removed unwanted changes added by mistake Changes in v2: - Merged write() function into existing 'clk_parent' file - Removed 'if (val >= core->num_parents)' check - Removed incorrect usage of IS_ERR_OR_NULL() drivers/clk/clk.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 65508eb89ec9..bf1eadfeaee0 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -3214,6 +3214,42 @@ static int current_parent_show(struct seq_file *s, void *data) } DEFINE_SHOW_ATTRIBUTE(current_parent); +#ifdef CLOCK_ALLOW_WRITE_DEBUGFS +static ssize_t current_parent_write(struct file *file, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct seq_file *s = file->private_data; + struct clk_core *core = s->private; + struct clk_core *parent; + u8 idx; + int err; + + err = kstrtou8_from_user(ubuf, count, 0, &idx); + if (err < 0) + return err; + + parent = clk_core_get_parent_by_index(core, idx); + if (!parent) + return -ENOENT; + + clk_prepare_lock(); + err = clk_core_set_parent_nolock(core, parent); + clk_prepare_unlock(); + if (err) + return err; + + return count; +} + +static const struct file_operations current_parent_rw_fops = { + .open = current_parent_open, + .write = current_parent_write, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif + static int clk_duty_cycle_show(struct seq_file *s, void *data) { struct clk_core *core = s->private; @@ -3281,6 +3317,12 @@ static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry) &clk_prepare_enable_fops); #endif +#ifdef CLOCK_ALLOW_WRITE_DEBUGFS + if (core->num_parents > 1) + debugfs_create_file("clk_parent", 0644, root, core, + ¤t_parent_rw_fops); + else +#endif if (core->num_parents > 0) debugfs_create_file("clk_parent", 0444, root, core, ¤t_parent_fops); -- 2.30.2