Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751782AbaJAN4E (ORCPT ); Wed, 1 Oct 2014 09:56:04 -0400 Received: from mail-la0-f44.google.com ([209.85.215.44]:54218 "EHLO mail-la0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751136AbaJAN4B (ORCPT ); Wed, 1 Oct 2014 09:56:01 -0400 MIME-Version: 1.0 In-Reply-To: <3038755.G9Y3LOUCHH@wuerfel> References: <1411992293-7729-1-git-send-email-zhang.lyra@gmail.com> <1411992293-7729-6-git-send-email-zhang.lyra@gmail.com> <3038755.G9Y3LOUCHH@wuerfel> From: Rob Herring Date: Wed, 1 Oct 2014 08:55:39 -0500 Message-ID: Subject: Re: [PATCH 5/6] tty/serial: Add Spreadtrum's serial earlycon To: Arnd Bergmann Cc: zhang.lyra@gmail.com, Catalin Marinas , Greg Kroah-Hartman , Ian Campbell , Jiri Slaby , Kumar Gala , Mark Brown , Mark Rutland , Murali Karicheri , Pawel Moll , artagnon@gmail.com, Robert Richter , Rob Herring , Will Deacon , orsonzhai@gmail.com, geng.ren@spreadtrum.com, zhizhou.zhang@spreadtrum.com, "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "chunyan.zhang" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 29, 2014 at 8:36 AM, Arnd Bergmann wrote: > On Monday 29 September 2014 20:04:52 zhang.lyra@gmail.com wrote: >> From: "chunyan.zhang" >> >> Adds earlycon support for the Spreadtrum's serial. >> >> Signed-off-by: chunyan.zhang >> --- >> drivers/tty/serial/Kconfig | 12 ++++++ >> drivers/tty/serial/Makefile | 1 + >> drivers/tty/serial/serial_sprd_early.c | 64 ++++++++++++++++++++++++++++++++ >> 3 files changed, 77 insertions(+) >> create mode 100644 drivers/tty/serial/serial_sprd_early.c >> >> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig >> index 26cec64..ede16e6 100644 >> --- a/drivers/tty/serial/Kconfig >> +++ b/drivers/tty/serial/Kconfig >> @@ -85,6 +85,18 @@ config SERIAL_EARLYCON_ARM_SEMIHOST >> with "earlycon=smh" on the kernel command line. The console is >> enabled when early_param is processed. >> >> +config SERIAL_EARLYCON_SPRD >> + bool "Early console using SPRD serial" >> + depends on ARM64 >> + select SERIAL_CORE >> + select SERIAL_CORE_CONSOLE >> + select SERIAL_EARLYCON >> + help > > I assume you will later want to have a proper device driver for > this hardware, so it would be better to make the Kconfig symbol > and the file name what you are going to use in the long run, but > for now only have the earlycon support included. > > >> +static int __init serial_sprd_early_console_setup( >> + struct earlycon_device *device, >> + const char *opt) >> +{ >> + if (!device->port.membase) >> + return -ENODEV; >> + >> + device->con->write = serial_sprd_early_write; >> + return 0; >> +} >> +EARLYCON_DECLARE(serial_sprd, serial_sprd_early_console_setup); >> +OF_EARLYCON_DECLARE(serial_sprd, "sprd,serial", >> + serial_sprd_early_console_setup); >> > > I think you should drop the EARLYCON_DECLARE() line, using > OF_EARLYCON_DECLARE should be enough. No, I've been telling people to put both in. The reason is you may have a bootloader or boot files (e.g PXELINUX) that only allows changing changing the command line or you want to override/extend the command line in the kernel. I'm thinking the declaration should be combined into one to do both since I'm getting tired of making this comment. Rob -- 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/