From patchwork Fri Apr 18 22:19:55 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rob Herring X-Patchwork-Id: 4018841 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 8C92C9F369 for ; Fri, 18 Apr 2014 22:23:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8D03D2012F for ; Fri, 18 Apr 2014 22:23:17 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 836AC202D1 for ; Fri, 18 Apr 2014 22:23:16 +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 1WbH9G-0003ew-Nm; Fri, 18 Apr 2014 22:20:42 +0000 Received: from mail-ob0-x231.google.com ([2607:f8b0:4003:c01::231]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WbH9D-0003dQ-BA for linux-arm-kernel@lists.infradead.org; Fri, 18 Apr 2014 22:20:40 +0000 Received: by mail-ob0-f177.google.com with SMTP id wp18so2204070obc.36 for ; Fri, 18 Apr 2014 15:20:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=arB+BTHADWNPTOjjJ0BFXr3+lH3g+9Y/bg/2CjaUdvU=; b=SnvlUajDtRC1JR7X+HwxWj6/vUkNC22kMxTORDs7JK2S5B5VzRE3Le85rnXiOyf02M sWs4Yz7KinqftMqz069ywCvGUqfUl93+tpF6F4uQFknE3E8D3ddeENUMiAY5ygxcs5C4 rRPiqtWqfgXXGd/hhdg4vwmacEbXT9RvEUL/t0KIAVCxu9GTmPURn6AyjZdi49QJLFAZ qS6ZECrmS6XUlQLATN0CS/06866HzkdZJ+EA2MrEY7v6N09d/62kC1B4SOyIuyi1N5ve aEjCbYatRQ21476du+PWPX+eutnzbZzi5Xh8gAaFEhFSsH8DQVPFckjbQ9EEH0eeIb9e Z6jQ== X-Received: by 10.60.95.230 with SMTP id dn6mr18998155oeb.25.1397859617941; Fri, 18 Apr 2014 15:20:17 -0700 (PDT) Received: from localhost.localdomain (72-48-77-163.dyn.grandenetworks.net. [72.48.77.163]) by mx.google.com with ESMTPSA id cq1sm131597992oeb.4.2014.04.18.15.20.17 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 18 Apr 2014 15:20:17 -0700 (PDT) From: Rob Herring To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: [PATCH v2 2/7] tty/serial: add generic serial earlycon Date: Fri, 18 Apr 2014 17:19:55 -0500 Message-Id: <1397859600-11507-3-git-send-email-robherring2@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1397859600-11507-1-git-send-email-robherring2@gmail.com> References: <1397859600-11507-1-git-send-email-robherring2@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140418_152039_493551_0D8C8871 X-CRM114-Status: GOOD ( 23.28 ) X-Spam-Score: 0.1 (/) Cc: Rob Herring , Russell King , Arnd Bergmann , Greg Kroah-Hartman , Will Deacon , Catalin Marinas , 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=-2.4 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RP_MATCHES_RCVD, T_DKIM_INVALID, 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 From: Rob Herring This introduces generic earlycon infrastructure for serial devices based on the 8250 earlycon. This allows for supporting earlycon option with other serial devices. The earlycon output is enabled at the time early_params are processed. Only architectures that have fixmap support or have functional ioremap when early_params are processed are supported. This is the same restriction that the 8250 driver had. Signed-off-by: Rob Herring Cc: Greg Kroah-Hartman Cc: Jiri Slaby --- v2: - Use set_fixmap_io/ioremap instead of set_fixmap_nocache/ioremap_nocache. - Do the mapping outside of option parsing function. drivers/tty/serial/Kconfig | 7 ++ drivers/tty/serial/Makefile | 2 + drivers/tty/serial/earlycon.c | 152 ++++++++++++++++++++++++++++++++++++++++++ include/linux/serial_core.h | 16 +++++ 4 files changed, 177 insertions(+) create mode 100644 drivers/tty/serial/earlycon.c diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 2e6d8dd..3b7c19b 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -7,6 +7,13 @@ if TTY menu "Serial drivers" depends on HAS_IOMEM +config SERIAL_EARLYCON + bool + help + Support for early consoles with the earlycon parameter. This enables + the console before standard serial driver is probed. The console is + enabled when early_param is processed. + source "drivers/tty/serial/8250/Kconfig" comment "Non-8250 serial port support" diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index 3680854..8af1415 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -5,6 +5,8 @@ obj-$(CONFIG_SERIAL_CORE) += serial_core.o obj-$(CONFIG_SERIAL_21285) += 21285.o +obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o + # These Sparc drivers have to appear before others such as 8250 # which share ttySx minor node space. Otherwise console device # names change and other unplesantries. diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c new file mode 100644 index 0000000..73bf1e2 --- /dev/null +++ b/drivers/tty/serial/earlycon.c @@ -0,0 +1,152 @@ +/* + * Copyright (C) 2014 Linaro Ltd. + * Author: Rob Herring + * + * Based on 8250 earlycon: + * (c) Copyright 2004 Hewlett-Packard Development Company, L.P. + * Bjorn Helgaas + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include +#include +#include +#include +#include + +#ifdef CONFIG_FIX_EARLYCON_MEM +#include +#endif + +#include + +static struct console early_con = { + .name = "earlycon", + .flags = CON_PRINTBUFFER | CON_BOOT, + .index = -1, +}; + +static struct earlycon_device early_console_dev = { + .con = &early_con, +}; + +static void __iomem * __init earlycon_map(unsigned long paddr, size_t size) +{ + void __iomem *base; +#ifdef CONFIG_FIX_EARLYCON_MEM + set_fixmap_io(FIX_EARLYCON_MEM_BASE, paddr & PAGE_MASK); + base = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE); + base += paddr & ~PAGE_MASK; +#else + base = ioremap(paddr, size); +#endif + if (!base) + pr_err("%s: Couldn't map 0x%llx\n", __func__, + (unsigned long long)paddr); + + return base; +} + +static int __init parse_options(struct earlycon_device *device, + char *options) +{ + struct uart_port *port = &device->port; + int mmio, mmio32, length, ret; + unsigned long addr; + + if (!options) + return -ENODEV; + + mmio = !strncmp(options, "mmio,", 5); + mmio32 = !strncmp(options, "mmio32,", 7); + if (mmio || mmio32) { + port->iotype = (mmio ? UPIO_MEM : UPIO_MEM32); + options += mmio ? 5 : 7; + ret = kstrtoul(options, 0, &addr); + if (ret) + return ret; + port->mapbase = addr; + if (mmio32) + port->regshift = 2; + } else if (!strncmp(options, "io,", 3)) { + port->iotype = UPIO_PORT; + options += 3; + ret = kstrtoul(options, 0, &addr); + if (ret) + return ret; + port->iobase = addr; + mmio = 0; + } else if (!strncmp(options, "0x", 2)) { + port->iotype = UPIO_MEM; + ret = kstrtoul(options, 0, &addr); + if (ret) + return ret; + port->mapbase = addr; + } else { + return -EINVAL; + } + + port->uartclk = BASE_BAUD * 16; + + options = strchr(options, ','); + if (options) { + options++; + ret = kstrtouint(options, 0, &device->baud); + if (ret) + return ret; + length = min(strcspn(options, " ") + 1, + (size_t)(sizeof(device->options))); + strlcpy(device->options, options, length); + } + + if (mmio || mmio32) + pr_info("Early serial console at MMIO%s 0x%llx (options '%s')\n", + mmio32 ? "32" : "", + (unsigned long long)port->mapbase, + device->options); + else + pr_info("Early serial console at I/O port 0x%lx (options '%s')\n", + port->iobase, + device->options); + + return 0; +} + +int __init setup_earlycon(char *buf, const char *match, + int (*setup)(struct earlycon_device *, const char *)) +{ + int err; + size_t len; + struct uart_port *port = &early_console_dev.port; + + if (!buf || !match || !setup) + return 0; + + len = strlen(match); + if (strncmp(buf, match, len)) + return 0; + if (buf[len] && (buf[len] != ',')) + return 0; + + buf += len + 1; + + err = parse_options(&early_console_dev, buf); + /* On parsing error, pass the options buf to the setup function */ + if (!err) + buf = NULL; + + if (port->mapbase) + port->membase = earlycon_map(port->mapbase, 64); + + early_console_dev.con->data = &early_console_dev; + err = setup(&early_console_dev, buf); + if (err < 0) + return err; + if (!early_console_dev.con->write) + return -ENODEV; + + register_console(early_console_dev.con); + return 0; +} diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index f729be9..7a15b5b 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -285,6 +285,22 @@ static inline int uart_poll_timeout(struct uart_port *port) /* * Console helpers. */ +struct earlycon_device { + struct console *con; + struct uart_port port; + char options[16]; /* e.g., 115200n8 */ + unsigned int baud; +}; +int setup_earlycon(char *buf, const char *match, + int (*setup)(struct earlycon_device *, const char *)); + +#define EARLYCON_DECLARE(name, func) \ +static int __init name ## _setup_earlycon(char *buf) \ +{ \ + return setup_earlycon(buf, __stringify(name), func); \ +} \ +early_param("earlycon", name ## _setup_earlycon); + struct uart_port *uart_get_console(struct uart_port *ports, int nr, struct console *c); void uart_parse_options(char *options, int *baud, int *parity, int *bits,