From patchwork Wed Aug 22 16:25:22 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Leach X-Patchwork-Id: 1362441 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id EA6403FC71 for ; Wed, 22 Aug 2012 16:28:35 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1T4DkJ-0004PY-Eg; Wed, 22 Aug 2012 16:25:31 +0000 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1T4DkF-0004Oz-T9 for linux-arm-kernel@lists.infradead.org; Wed, 22 Aug 2012 16:25:29 +0000 Received: from localhost.localdomain (e106299-lin.cambridge.arm.com [10.1.193.74]) by cam-admin0.cambridge.arm.com (8.12.6/8.12.6) with ESMTP id q7MGPNE7022360; Wed, 22 Aug 2012 17:25:23 +0100 (BST) From: Matthew Leach To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3] serial: pl011: honour serial aliases in device tree Date: Wed, 22 Aug 2012 17:25:22 +0100 Message-Id: <1345652722-22668-1-git-send-email-matthew.leach@arm.com> X-Mailer: git-send-email 1.7.0.4 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -7.1 (-------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-7.1 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [217.140.96.50 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.2 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Matthew Leach , gregkh@linuxfoundation.org, devicetree-discuss@lists.ozlabs.org, will.deacon@arm.com, linux-serial@vger.kernel.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org If the order of UART nodes is changed in the device tree, then tty dev devices are attached to different serial ports causing the console to be directed to a different physical serial port. The "serial" aliases in the device tree should prevent this. This patch ensures that the UART driver creates tty devices that honour these aliases if a device tree is present. Acked-by: Linus Walleij Reviewed-by: Will Deacon Acked-by: Rob Herring Signed-off-by: Matthew Leach --- v3: minor consistency correction v2: use IS_ENABLED instead of ifdefs drivers/tty/serial/amba-pl011.c | 36 ++++++++++++++++++++++++++++++++++++ 1 files changed, 36 insertions(+), 0 deletions(-) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index d3553b5..dc05dd1 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -52,6 +52,8 @@ #include #include #include +#include +#include #include #include @@ -1869,6 +1871,38 @@ static struct uart_driver amba_reg = { .cons = AMBA_CONSOLE, }; +static int pl011_probe_dt_alias(int index, struct device *dev) +{ + struct device_node *np; + static bool seen_dev_with_alias = false; + static bool seen_dev_without_alias = false; + int ret = index; + + if (!IS_ENABLED(CONFIG_OF)) + return ret; + + np = dev->of_node; + if (!np) + return ret; + + ret = of_alias_get_id(np, "serial"); + if (IS_ERR_VALUE(ret)) { + seen_dev_without_alias = true; + ret = index; + } else { + seen_dev_with_alias = true; + if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) { + dev_warn(dev, "requested serial port %d not available.\n", ret); + ret = index; + } + } + + if (seen_dev_with_alias && seen_dev_without_alias) + dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n"); + + return ret; +} + static int pl011_probe(struct amba_device *dev, const struct amba_id *id) { struct uart_amba_port *uap; @@ -1891,6 +1925,8 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id) goto out; } + i = pl011_probe_dt_alias(i, &dev->dev); + base = ioremap(dev->res.start, resource_size(&dev->res)); if (!base) { ret = -ENOMEM;