From patchwork Wed Aug 28 13:23:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 11119001 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C5DA214D5 for ; Wed, 28 Aug 2019 13:23:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE5AB22DA7 for ; Wed, 28 Aug 2019 13:23:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726472AbfH1NXQ (ORCPT ); Wed, 28 Aug 2019 09:23:16 -0400 Received: from laurent.telenet-ops.be ([195.130.137.89]:60034 "EHLO laurent.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726394AbfH1NXP (ORCPT ); Wed, 28 Aug 2019 09:23:15 -0400 Received: from ramsan ([84.194.98.4]) by laurent.telenet-ops.be with bizsmtp id udPD2000605gfCL01dPDy1; Wed, 28 Aug 2019 15:23:13 +0200 Received: from rox.of.borg ([192.168.97.57]) by ramsan with esmtp (Exim 4.90_1) (envelope-from ) id 1i2xur-00009L-3a; Wed, 28 Aug 2019 15:23:13 +0200 Received: from geert by rox.of.borg with local (Exim 4.90_1) (envelope-from ) id 1i2xur-0004xS-1U; Wed, 28 Aug 2019 15:23:13 +0200 From: Geert Uytterhoeven To: Michael Turquette , Stephen Boyd Cc: Raman Banka , linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v2] clk: Add support for setting clk_rate via debugfs Date: Wed, 28 Aug 2019 15:23:06 +0200 Message-Id: <20190828132306.19012-1-geert+renesas@glider.be> X-Mailer: git-send-email 2.17.1 Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org For testing, it is useful to be able to specify a clock rate manually. As this is a dangerous feature, it is not enabled by default. Users need to modify the source directly and #define CLOCK_ALLOW_WRITE_DEBUGFS. This follows the spirit of commit 09c6ecd394105c48 ("regmap: Add support for writing to regmap registers via debugfs"). Signed-off-by: Geert Uytterhoeven --- Stephen: you suggested this approach in https://lore.kernel.org/linux-clk/153029668040.143105.2059491089047180792@swboyd.mtv.corp.google.com/ v2: - Rebased. --- drivers/clk/clk.c | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 2ba52b8dafcc1cc5..5b3c915b9507634c 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2990,6 +2990,41 @@ static int clk_dump_show(struct seq_file *s, void *data) } DEFINE_SHOW_ATTRIBUTE(clk_dump); +#undef CLOCK_ALLOW_WRITE_DEBUGFS +#ifdef CLOCK_ALLOW_WRITE_DEBUGFS +/* + * This can be dangerous, therefore don't provide any real compile time + * configuration option for this feature. + * People who want to use this will need to modify the source code directly. + */ +static int clk_rate_set(void *data, u64 val) +{ + struct clk_core *core = data; + int ret; + + clk_prepare_lock(); + ret = clk_core_set_rate_nolock(core, val); + clk_prepare_unlock(); + + return ret; +} + +#define clk_rate_mode 0644 +#else +#define clk_rate_set NULL +#define clk_rate_mode 0444 +#endif + +static int clk_rate_get(void *data, u64 *val) +{ + struct clk_core *core = data; + + *val = core->rate; + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n"); + static const struct { unsigned long flag; const char *name; @@ -3139,7 +3174,8 @@ static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry) root = debugfs_create_dir(core->name, pdentry); core->dentry = root; - debugfs_create_ulong("clk_rate", 0444, root, &core->rate); + debugfs_create_file("clk_rate", clk_rate_mode, root, core, + &clk_rate_fops); debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops); debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops); debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);