Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752556AbaLRIeJ (ORCPT ); Thu, 18 Dec 2014 03:34:09 -0500 Received: from mailgw02.mediatek.com ([210.61.82.184]:58479 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752385AbaLRIeE (ORCPT ); Thu, 18 Dec 2014 03:34:04 -0500 X-Listener-Flag: 11101 From: Eddie Huang To: Mark Rutland , Greg Kroah-Hartman , Matthias Brugger CC: , Rob Herring , Pawel Moll , Ian Campbell , Kumar Gala , Catalin Marinas , Will Deacon , Jiri Slaby , Eddie Huang , Alan Cox , , , , , Sascha Hauer , , Subject: [PATCH 1/2] tty: serial: 8250_mtk: Add earlycon Date: Thu, 18 Dec 2014 16:33:20 +0800 Message-ID: <1418891601-53769-2-git-send-email-eddie.huang@mediatek.com> X-Mailer: git-send-email 1.8.1.1.dirty In-Reply-To: <1418891601-53769-1-git-send-email-eddie.huang@mediatek.com> References: <1418891601-53769-1-git-send-email-eddie.huang@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mediatek UART has highspeed register, but 8250_early.c doesn't support this, so add earlycon in 8250_mtk.c Signed-off-by: Eddie Huang --- drivers/tty/serial/8250/8250_mtk.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c index de7aae5..65dd569 100644 --- a/drivers/tty/serial/8250/8250_mtk.c +++ b/drivers/tty/serial/8250/8250_mtk.c @@ -23,6 +23,7 @@ #include #include #include +#include #include "8250.h" @@ -289,6 +290,38 @@ static struct platform_driver mtk8250_platform_driver = { }; module_platform_driver(mtk8250_platform_driver); +#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) + +static void __init mtk8250_serial_putc(struct uart_port *port, int c) +{ + while ((readl(port->membase + (UART_LSR << 2)) & BOTH_EMPTY) != + BOTH_EMPTY) + ; + writel(c, port->membase + (UART_TX << 2)); +} + +static void __init early_mtk8250_write(struct console *console, + const char *s, unsigned int count) +{ + struct earlycon_device *dev = console->data; + + uart_console_write(&dev->port, s, count, mtk8250_serial_putc); +} + +static int __init early_mtk8250_setup(struct earlycon_device *device, + const char *options) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = early_mtk8250_write; + + return 0; +} + +EARLYCON_DECLARE(mtk8250, early_mtk8250_setup); +OF_EARLYCON_DECLARE(mtk8250, "mediatek,mt6577-uart", early_mtk8250_setup); + MODULE_AUTHOR("Matthias Brugger"); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Mediatek 8250 serial port driver"); -- 1.8.1.1.dirty -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/