From patchwork Sun Nov 17 23:06:10 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerhard Sittig X-Patchwork-Id: 3195051 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 0920E9F514 for ; Sun, 17 Nov 2013 23:29:49 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1BCE3206B0 for ; Sun, 17 Nov 2013 23:29:48 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 664AC206AA for ; Sun, 17 Nov 2013 23:29:46 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ViBUD-0000UP-W1; 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Mon, 18 Nov 2013 00:08:17 +0100 (CET) X-Auth-Info: Lflr0ydwJOZ3PyM2SDaLyi4nnvHplh1Ja2TH0AYZ6Lw= Received: from localhost (host-82-135-33-74.customer.m-online.net [82.135.33.74]) by mail.mnet-online.de (Postfix) with ESMTPA; Mon, 18 Nov 2013 00:08:17 +0100 (CET) From: Gerhard Sittig To: linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, Anatolij Gustschin , Mike Turquette Subject: [PATCH v5 10/17] serial: mpc512x: setup the PSC FIFO clock as well Date: Mon, 18 Nov 2013 00:06:10 +0100 Message-Id: <1384729577-7336-11-git-send-email-gsi@denx.de> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1384729577-7336-1-git-send-email-gsi@denx.de> References: <1384729577-7336-1-git-send-email-gsi@denx.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131117_180843_184597_30500D11 X-CRM114-Status: GOOD ( 14.24 ) X-Spam-Score: -1.9 (-) Cc: Detlev Zundel , Greg Kroah-Hartman , Gerhard Sittig , linux-serial@vger.kernel.org, Scott Wood , Jiri Slaby X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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=-4.7 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 prepare and enable the FIFO clock upon PSC FIFO initialization, check for and propagage errors when enabling the PSC FIFO clock, disable and unprepare the FIFO clock upon PSC FIFO uninitialization devm_{get,put}_clk() doesn't apply here, as the SoC provides a single FIFO component which is shared among several PSC components, thus the FIFO isn't associated with a device (while the PSCs are) provide a fallback clock lookup approach in case the OF based clock lookup for the PSC FIFO fails, this allows for successful operation in the presence of an outdated device tree which lacks clock specs Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: linux-serial@vger.kernel.org Acked-by: Greg Kroah-Hartman # for v4 Signed-off-by: Gerhard Sittig --- Greg, the addition since v4 is the clk_get_sys() call for the 'ipg' clock item (backwards compat for device trees w/o clock specs) --- drivers/tty/serial/mpc52xx_uart.c | 50 ++++++++++++++++++++++++++++++++----- 1 file changed, 44 insertions(+), 6 deletions(-) diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c index 1d1dbe9d5af2..78c8cbadc776 100644 --- a/drivers/tty/serial/mpc52xx_uart.c +++ b/drivers/tty/serial/mpc52xx_uart.c @@ -421,6 +421,7 @@ struct psc_fifoc { static struct psc_fifoc __iomem *psc_fifoc; static unsigned int psc_fifoc_irq; +static struct clk *psc_fifoc_clk; static void mpc512x_psc_fifo_init(struct uart_port *port) { @@ -568,36 +569,73 @@ static unsigned int mpc512x_psc_set_baudrate(struct uart_port *port, /* Init PSC FIFO Controller */ static int __init mpc512x_psc_fifoc_init(void) { + int err; struct device_node *np; + struct clk *clk; + + /* default error code, potentially overwritten by clock calls */ + err = -ENODEV; np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-psc-fifo"); if (!np) { pr_err("%s: Can't find FIFOC node\n", __func__); - return -ENODEV; + goto out_err; + } + + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) { + /* backwards compat with device trees that lack clock specs */ + clk = clk_get_sys(np->name, "ipg"); + } + if (IS_ERR(clk)) { + pr_err("%s: Can't lookup FIFO clock\n", __func__); + err = PTR_ERR(clk); + goto out_ofnode_put; + } + if (clk_prepare_enable(clk)) { + pr_err("%s: Can't enable FIFO clock\n", __func__); + clk_put(clk); + goto out_ofnode_put; } + psc_fifoc_clk = clk; psc_fifoc = of_iomap(np, 0); if (!psc_fifoc) { pr_err("%s: Can't map FIFOC\n", __func__); - of_node_put(np); - return -ENODEV; + goto out_clk_disable; } psc_fifoc_irq = irq_of_parse_and_map(np, 0); - of_node_put(np); if (psc_fifoc_irq == 0) { pr_err("%s: Can't get FIFOC irq\n", __func__); - iounmap(psc_fifoc); - return -ENODEV; + goto out_unmap; } + of_node_put(np); return 0; + +out_unmap: + iounmap(psc_fifoc); +out_clk_disable: + clk_disable_unprepare(psc_fifoc_clk); + clk_put(psc_fifoc_clk); +out_ofnode_put: + of_node_put(np); +out_err: + return err; } static void __exit mpc512x_psc_fifoc_uninit(void) { iounmap(psc_fifoc); + + /* disable the clock, errors are not fatal */ + if (psc_fifoc_clk) { + clk_disable_unprepare(psc_fifoc_clk); + clk_put(psc_fifoc_clk); + psc_fifoc_clk = NULL; + } } /* 512x specific interrupt handler. The caller holds the port lock */