From patchwork Mon Sep 21 16:53:57 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas Stach X-Patchwork-Id: 7233021 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id BEAD8BEEC1 for ; Mon, 21 Sep 2015 16:57:01 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E97462070A for ; Mon, 21 Sep 2015 16:57:00 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1B3D12070E for ; Mon, 21 Sep 2015 16:57:00 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ze4MT-0008FH-PF; Mon, 21 Sep 2015 16:54:41 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ze4MJ-00089W-Ud for linux-arm-kernel@lists.infradead.org; Mon, 21 Sep 2015 16:54:32 +0000 Received: from dude.hi.4.pengutronix.de ([10.1.0.7] helo=dude.pengutronix.de.) by metis.ext.pengutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1Ze4Lu-0006Di-8g; Mon, 21 Sep 2015 18:54:06 +0200 From: Lucas Stach To: Shawn Guo Subject: [PATCH v4 1/8] clk: imx: add common logic to detect early UART usage Date: Mon, 21 Sep 2015 18:53:57 +0200 Message-Id: <1442854444-4460-2-git-send-email-l.stach@pengutronix.de> X-Mailer: git-send-email 2.5.1 In-Reply-To: <1442854444-4460-1-git-send-email-l.stach@pengutronix.de> References: <1442854444-4460-1-git-send-email-l.stach@pengutronix.de> X-SA-Exim-Connect-IP: 10.1.0.7 X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150921_095432_242747_17F0B404 X-CRM114-Status: GOOD ( 11.37 ) X-Spam-Score: -1.9 (-) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Michael Turquette , Stephen Boyd , patchwork-lst@pengutronix.de, kernel@pengutronix.de, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Both earlycon and eralyprintk depend on the bootloader setup UART clocks being retained. This patch adds the common logic to detect such situations and make the information available to the clock drivers, as well as adding the facilities to disable those clocks at the end of the kernel init. Signed-off-by: Lucas Stach --- drivers/clk/imx/clk.c | 38 ++++++++++++++++++++++++++++++++++++++ drivers/clk/imx/clk.h | 1 + 2 files changed, 39 insertions(+) diff --git a/drivers/clk/imx/clk.c b/drivers/clk/imx/clk.c index df12b5307175..a634b1185be3 100644 --- a/drivers/clk/imx/clk.c +++ b/drivers/clk/imx/clk.c @@ -73,3 +73,41 @@ void imx_cscmr1_fixup(u32 *val) *val ^= CSCMR1_FIXUP; return; } + +static int imx_keep_uart_clocks __initdata; +static struct clk ** const *imx_uart_clocks __initdata; + +static int __init imx_keep_uart_clocks_param(char *str) +{ + imx_keep_uart_clocks = 1; + + return 0; +} +__setup_param("earlycon", imx_keep_uart_earlycon, + imx_keep_uart_clocks_param, 0); +__setup_param("earlyprintk", imx_keep_uart_earlyprintk, + imx_keep_uart_clocks_param, 0); + +void __init imx_register_uart_clocks(struct clk ** const clks[]) +{ + if (imx_keep_uart_clocks) { + int i; + + imx_uart_clocks = clks; + for (i = 0; imx_uart_clocks[i]; i++) + clk_prepare_enable(*imx_uart_clocks[i]); + } +} + +static int __init imx_clk_disable_uart(void) +{ + if (imx_keep_uart_clocks && imx_uart_clocks) { + int i; + + for (i = 0; imx_uart_clocks[i]; i++) + clk_disable_unprepare(*imx_uart_clocks[i]); + } + + return 0; +} +late_initcall_sync(imx_clk_disable_uart); diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h index 1049b0c7d818..c94ac5c26226 100644 --- a/drivers/clk/imx/clk.h +++ b/drivers/clk/imx/clk.h @@ -7,6 +7,7 @@ extern spinlock_t imx_ccm_lock; void imx_check_clocks(struct clk *clks[], unsigned int count); +void imx_register_uart_clocks(struct clk ** const clks[]); extern void imx_cscmr1_fixup(u32 *val);