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 CE265C433F5 for ; Thu, 7 Oct 2021 18:22:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B475760EB4 for ; Thu, 7 Oct 2021 18:22:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243602AbhJGSX5 (ORCPT ); Thu, 7 Oct 2021 14:23:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233796AbhJGSX4 (ORCPT ); Thu, 7 Oct 2021 14:23:56 -0400 Received: from mail-lf1-x131.google.com (mail-lf1-x131.google.com [IPv6:2a00:1450:4864:20::131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E903DC061755 for ; Thu, 7 Oct 2021 11:22:01 -0700 (PDT) Received: by mail-lf1-x131.google.com with SMTP id m3so28729692lfu.2 for ; Thu, 07 Oct 2021 11:22:01 -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=RePy4YWN0QrSCoH4w20ZWl3nlKJKvtiMzhDlSX/yriY=; b=OxR9W+NREOChsdjDuhEuI7PNX0M+3YLpGr9UjwguYPWOZggjQMn2QUNfNgwKQqa9F6 V9Hi+egHduzv1YkEWEIr0SXHe5LUb2XrzrH3xfDwldcbiabvUcr0hAzwcJf7jZstBoZu CGOHJtz9COkNmXL3XHmax8r2WkMjR955917ml2JcoOtjl1WmlYbbCDsIsR5f06uTagC6 L46CjBUSPiYsunaYJw854kzuBjBmCw6/mEWboopgjBGwk0WeHLpWg2FvkuWTss0M2SUS r42QUzwMI0ksMLJoMFMUYdA4C9cae8/e6GSFC/97DaBFUUIoEVgYkZU2V3ctO94khGhb vHzw== 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=RePy4YWN0QrSCoH4w20ZWl3nlKJKvtiMzhDlSX/yriY=; b=gwx09xadVH+P+qABh4q81efkS22Z4gCuZUUx7WJqTfutJ1QpeVk+bLWw7w1F2lZ/l1 ncZshZIlBY1eximtOcDQ1gGvWVsPWx4YcUqUOL3OLU2Pf2zN8ghNCBtQUKurMwSx4c/H vPzlMmtKopoZ0TBypmmqsdGK/JB90w7EFuRuOJLOSnCDVAAWywCnP2VSLuj4IcRegR5C 4FThcRlQlJu/xEopDZbLca489YLgTgitKJLNF+dueRi40qGC8kF/PFq6pfFV1MtQj6rS R7A3uwAKPsfxfJlV0UAEii5jMS0zFHa5EfE3+rblqWCvNx4UgSJd4w/D83km1oVABAoK Hbpw== X-Gm-Message-State: AOAM532jZ1s9vEmkTkhd9+i7Ho1/SFQzNyOgp3AtGltiLUjdXk4x6hJ7 E/f9mcH0xq0ZkuCqUTyX2hGQGw== X-Google-Smtp-Source: ABdhPJykk3FE+YFgHXntejj5zMNl7VFdjwhG6jc9O1q6+cMbS6+8ktVb/uAvHVg8NfSkvUmr3wsIAQ== X-Received: by 2002:a05:6512:3c95:: with SMTP id h21mr5851195lfv.128.1633630920288; Thu, 07 Oct 2021 11:22:00 -0700 (PDT) Received: from localhost ([31.134.121.151]) by smtp.gmail.com with ESMTPSA id v23sm8069ljj.97.2021.10.07.11.21.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Oct 2021 11:21:59 -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 v5] clk: Add write operation for clk_parent debugfs node Date: Thu, 7 Oct 2021 21:21:58 +0300 Message-Id: <20211007182158.7490-1-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 --- 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 | 50 ++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 47 insertions(+), 3 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 806c55f0991b..6154d5bc2b45 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -3224,6 +3224,42 @@ 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; @@ -3291,9 +3327,17 @@ static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry) &clk_prepare_enable_fops); #endif - if (core->num_parents > 0) - debugfs_create_file("clk_parent", 0444, root, core, - ¤t_parent_fops); +#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); + } if (core->num_parents > 1) debugfs_create_file("clk_possible_parents", 0444, root, core, -- 2.30.2