From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Thu, 09 Nov 2023 12:48:27 +0100 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1r13WM-0048mH-2v for lore@lore.pengutronix.de; Thu, 09 Nov 2023 12:48:27 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1r13WM-000323-Qn for lore@pengutronix.de; Thu, 09 Nov 2023 12:48:27 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:To:From:Reply-To:Cc:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=wliqfTAm6L2UgsvvFHczye2yosHvdD9mHe2tf8/uh50=; b=4FKLC9KZexOBIT+fsLfkkX96IG muzACHZJWfiGUNX6314mRz2UApyubcqKHpY8pufq2foAG1TqCQjm8GL6ujSBUMgDiCof3B7a+y4rw egRIm7xETVdlseco03cZZSJMvhXxxMhWWZ0MJB1m3uMzeI93fy5FAGCujY3Wbvm47WUCRQTxdt1GB jiEisuSGtGL4T6trASjbDDTFdjB/+rukvzOVB/AMk/uKR8bozVRqNFfGA6ABPZ3SLu9EKdFTuT6RM aIIuKm4rF4E3qrefvVkxVtOJ32Po7saeZ4aJz48K6uRExhmXQ3c3nJ6ngAkquYXNCbNRhCf48g3QZ SQoDCYgA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r13VD-006921-2M; Thu, 09 Nov 2023 11:47:15 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r13VA-0068zQ-1s for barebox@lists.infradead.org; Thu, 09 Nov 2023 11:47:13 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1r13V9-0002k5-8p for barebox@lists.infradead.org; Thu, 09 Nov 2023 12:47:11 +0100 Received: from [2a0a:edc0:0:1101:1d::54] (helo=dude05.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1r13V8-007lck-Se for barebox@lists.infradead.org; Thu, 09 Nov 2023 12:47:10 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1r13V8-005gNP-2a for barebox@lists.infradead.org; Thu, 09 Nov 2023 12:47:10 +0100 From: Ahmad Fatoum To: barebox@lists.infradead.org Date: Thu, 9 Nov 2023 12:47:06 +0100 Message-Id: <20231109114707.1354502-1-a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231109_034712_620869_DCA62A8B X-CRM114-Status: GOOD ( 16.91 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-4.9 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH 1/2] console: provide best-effort clk_get_for_console helper X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) From: Ahmad Fatoum clk_get will return -EPROBE_DEFER if clock provider hasn't yet been probed. In a system with deep probe enabled, dependencies are probed on demand, so a -EPROBE_DEFER return is final and the console probe will never succeed. CONFIG_DEBUG_LL is often used to debug this, but because the low-level console is not interactive, it's a bit cumbersome. Improve upon this a bit, by providing a clk_get_for_console helper that returns NULL if and only if we are sure that a clock provider will not be probed. In that case, the driver can skip code paths initialization code and baud rate setting dependent on having access to the clock and still register a console that reuses what was set up by CONFIG_DEBUG_LL. Signed-off-by: Ahmad Fatoum --- include/console.h | 26 ++++++++++++++++++++++++++ include/linux/clk.h | 21 +++++++++++++++++++++ 2 files changed, 47 insertions(+) diff --git a/include/console.h b/include/console.h index 586b68f73301..b8c901801e9f 100644 --- a/include/console.h +++ b/include/console.h @@ -8,6 +8,7 @@ #define _CONSOLE_H_ #include +#include #include #include #include @@ -208,4 +209,29 @@ static inline void console_ctrlc_allow(void) { } static inline void console_ctrlc_forbid(void) { } #endif +/** + * clk_get_for_console - get clock, ignoring known unavailable clock controller + * @dev: device for clock "consumer" + * @id: clock consumer ID + * + * Return: a struct clk corresponding to the clock producer, a + * valid IS_ERR() condition containing errno or NULL if it could + * be determined that the clock producer will never be probed in + * absence of modules. The NULL return allows serial drivers to + * skip clock handling and rely on CONFIG_DEBUG_LL. + */ +static inline struct clk *clk_get_for_console(struct device *dev, const char *id) +{ + struct clk *clk; + + if (!IS_ENABLED(CONFIG_DEBUG_LL)) + return clk_get(dev, id); + + clk = clk_get_if_available(dev, id); + if (clk == NULL) + dev_warn(dev, "couldn't get clock (ignoring)\n"); + + return clk; +} + #endif diff --git a/include/linux/clk.h b/include/linux/clk.h index 61b4ff3127cf..f505f18a75c0 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -14,6 +14,7 @@ #include #include #include +#include #include struct device; @@ -982,4 +983,24 @@ static inline struct clk *clk_get_enabled(struct device *dev, const char *id) return clk; } +/** + * clk_get_if_available - get clock, ignoring known unavailable clock controller + * @dev: device for clock "consumer" + * @id: clock consumer ID + * + * Return: a struct clk corresponding to the clock producer, a + * valid IS_ERR() condition containing errno or NULL if it could + * be determined that the clock producer will never be probed in + * absence of modules. + */ +static inline struct clk *clk_get_if_available(struct device *dev, const char *id) +{ + struct clk *clk = clk_get(dev, id); + + if (clk == ERR_PTR(-EPROBE_DEFER) && deep_probe_is_supported()) + return NULL; + + return clk; +} + #endif -- 2.39.2