From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751782AbdASKCM (ORCPT ); Thu, 19 Jan 2017 05:02:12 -0500 Received: from fllnx209.ext.ti.com ([198.47.19.16]:56643 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751682AbdASKCK (ORCPT ); Thu, 19 Jan 2017 05:02:10 -0500 From: Lokesh Vutla To: Greg Kroah-Hartman , Jiri Slaby CC: , Linux OMAP Mailing List , , Tero Kristo , Sekhar Nori , Tony Lindgren , Lokesh Vutla Subject: [PATCH] serial: omap: Add omapserial earlycon Date: Thu, 19 Jan 2017 15:29:38 +0530 Message-ID: <20170119095938.30976-1-lokeshvutla@ti.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add DT earlycon for omap_serial driver. This boot console is included with CONFIG_SERIAL_EARLYCON=y, CONFIG_OF=y, CONFIG_SERIAL_OMAP=y, and CONFIG_OF_EARLY_FLATTREE=y. This boot console is enabled with the command line option "earlycon" (without "=...") when the DT 'stdout-path' property matches a compatible uart. Signed-off-by: Lokesh Vutla --- drivers/tty/serial/omap-serial.c | 55 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index a2a529994ba5..3bbc4b5b6245 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -1234,6 +1234,61 @@ static int serial_omap_poll_get_char(struct uart_port *port) #ifdef CONFIG_SERIAL_OMAP_CONSOLE +#ifdef CONFIG_SERIAL_EARLYCON +static unsigned int __init omap_serial_early_in(struct uart_port *port, + int offset) +{ + offset <<= port->regshift; + return readw(port->membase + offset); +} + +static void __init omap_serial_early_out(struct uart_port *port, int offset, + int value) +{ + offset <<= port->regshift; + writew(value, port->membase + offset); +} + +static void __init omap_serial_early_putc(struct uart_port *port, int c) +{ + unsigned int status; + + for (;;) { + status = omap_serial_early_in(port, UART_LSR); + if ((status & BOTH_EMPTY) == BOTH_EMPTY) + break; + cpu_relax(); + } + omap_serial_early_out(port, UART_TX, c); +} + +static void __init early_omap_serial_write(struct console *console, + const char *s, unsigned int count) +{ + struct earlycon_device *device = console->data; + struct uart_port *port = &device->port; + + uart_console_write(port, s, count, omap_serial_early_putc); +} + +static int __init early_omap_serial_setup(struct earlycon_device *device, + const char *options) +{ + struct uart_port *port = &device->port; + + if (!(device->port.membase || device->port.iobase)) + return -ENODEV; + + port->regshift = 2; + device->con->write = early_omap_serial_write; + return 0; +} + +OF_EARLYCON_DECLARE(omapserial, "ti,omap2-uart", early_omap_serial_setup); +OF_EARLYCON_DECLARE(omapserial, "ti,omap3-uart", early_omap_serial_setup); +OF_EARLYCON_DECLARE(omapserial, "ti,omap4-uart", early_omap_serial_setup); +#endif /* CONFIG_SERIAL_EARLYCON */ + static struct uart_omap_port *serial_omap_console_ports[OMAP_MAX_HSUART_PORTS]; static struct uart_driver serial_omap_reg; -- 2.11.0