From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Cernekee Subject: [PATCH/RFC 8/8] serial: pxa: Add OF_EARLYCON support Date: Wed, 12 Nov 2014 00:46:33 -0800 Message-ID: <1415781993-7755-9-git-send-email-cernekee@gmail.com> References: <1415781993-7755-1-git-send-email-cernekee@gmail.com> Return-path: Received: from mail-pd0-f171.google.com ([209.85.192.171]:37907 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752139AbaKLIrT (ORCPT ); Wed, 12 Nov 2014 03:47:19 -0500 In-Reply-To: <1415781993-7755-1-git-send-email-cernekee@gmail.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: gregkh@linuxfoundation.org, jslaby@suse.cz, robh@kernel.org Cc: tushar.behera@linaro.org, daniel@zonque.org, haojian.zhuang@gmail.com, robert.jarzmik@free.fr, grant.likely@linaro.org, f.fainelli@gmail.com, mbizon@freebox.fr, jogo@openwrt.org, linux-mips@linux-mips.org, linux-serial@vger.kernel.org, devicetree@vger.kernel.org Implement a bare bones earlycon; this assumes that the bootloader sets up the tty parameters. Matches all three compatible strings. Signed-off-by: Kevin Cernekee --- drivers/tty/serial/pxa.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c index f6cc773..0764cf5 100644 --- a/drivers/tty/serial/pxa.c +++ b/drivers/tty/serial/pxa.c @@ -761,6 +761,51 @@ static struct console serial_pxa_console = { .data = &serial_pxa_reg, }; +static struct uart_pxa_port serial_pxa_early_port; + +static void __init early_wait_for_xmitr(struct uart_pxa_port *up) +{ + /* it's unsafe to call udelay() in the "early" variant */ + while ((serial_in(up, UART_LSR) & BOTH_EMPTY) != BOTH_EMPTY) + ; +} + +static void __init serial_pxa_early_putchar(struct uart_port *port, int ch) +{ + struct uart_pxa_port *up = (struct uart_pxa_port *)port; + + early_wait_for_xmitr(up); + serial_out(up, UART_TX, ch); +} + +static void __init serial_pxa_early_write(struct console *con, const char *s, + unsigned n) +{ + uart_console_write(&serial_pxa_early_port.port, s, n, + serial_pxa_early_putchar); + early_wait_for_xmitr(&serial_pxa_early_port); +} + +static int __init serial_pxa_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + serial_pxa_early_port.port.membase = device->port.membase; + serial_pxa_early_port.port.big_endian = device->port.big_endian; + + device->con->write = serial_pxa_early_write; + return 0; +} + +OF_EARLYCON_DECLARE(pxa_uart, "mrvl,pxa-uart", + serial_pxa_early_console_setup); +OF_EARLYCON_DECLARE(mmp_uart, "mrvl,mmp-uart", + serial_pxa_early_console_setup); +OF_EARLYCON_DECLARE(bcm7401_upg_uart, "brcm,bcm7401-upg-uart", + serial_pxa_early_console_setup); + #define PXA_CONSOLE &serial_pxa_console #else #define PXA_CONSOLE NULL -- 2.1.1