From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757746AbbLBXjG (ORCPT ); Wed, 2 Dec 2015 18:39:06 -0500 Received: from mail-ig0-f179.google.com ([209.85.213.179]:34754 "EHLO mail-ig0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757367AbbLBXjB (ORCPT ); Wed, 2 Dec 2015 18:39:01 -0500 Subject: Re: [PATCH 01/28] serial: earlycon: allow MEM32 I/O for DT earlycon To: Rob Herring , Paul Burton References: <1448900513-20856-1-git-send-email-paul.burton@imgtec.com> <1448900513-20856-2-git-send-email-paul.burton@imgtec.com> Cc: Linux-MIPS , "devicetree@vger.kernel.org" , Jiri Slaby , "linux-kernel@vger.kernel.org" , Grant Likely , Greg Kroah-Hartman , "linux-serial@vger.kernel.org" , Frank Rowand From: Peter Hurley Message-ID: <565F8112.8040907@hurleysoftware.com> Date: Wed, 2 Dec 2015 18:38:58 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/30/2015 05:52 PM, Rob Herring wrote: > On Mon, Nov 30, 2015 at 10:21 AM, Paul Burton wrote: >> Read the reg-io-width property when earlycon is setup via device tree, >> and set the I/O type to UPIO_MEM32 when 4 is read. This behaviour >> matches that of the of_serial driver, and is needed for DT configured >> earlycon on the MIPS Boston board. >> >> Note that this is only possible when CONFIG_LIBFDT is enabled, but >> enabling it everywhere seems like overkill. Thus systems that need this >> functionality should select CONFIG_LIBFDT for themselves. > > libfdt is enabled if you are booting from DT, so checking this > property should not add anything. > >> >> Signed-off-by: Paul Burton >> --- >> >> drivers/of/fdt.c | 2 +- >> drivers/tty/serial/Makefile | 1 + >> drivers/tty/serial/earlycon.c | 15 ++++++++++++++- >> include/linux/serial_core.h | 2 +- >> 4 files changed, 17 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c >> index d243029..71c7f0d 100644 >> --- a/drivers/of/fdt.c >> +++ b/drivers/of/fdt.c >> @@ -833,7 +833,7 @@ static int __init early_init_dt_scan_chosen_serial(void) >> if (addr == OF_BAD_ADDR) >> return -ENXIO; >> >> - of_setup_earlycon(addr, match->data); >> + of_setup_earlycon(fdt, offset, addr, match->data); >> return 0; >> } >> return -ENODEV; >> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile >> index 5ab4111..1d290d6 100644 >> --- a/drivers/tty/serial/Makefile >> +++ b/drivers/tty/serial/Makefile >> @@ -7,6 +7,7 @@ obj-$(CONFIG_SERIAL_21285) += 21285.o >> >> obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o >> obj-$(CONFIG_SERIAL_EARLYCON_ARM_SEMIHOST) += earlycon-arm-semihost.o >> +CFLAGS_earlycon.o += -I$(srctree)/scripts/dtc/libfdt > > This is no longer necessary. > >> >> # These Sparc drivers have to appear before others such as 8250 >> # which share ttySx minor node space. Otherwise console device >> diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c >> index f096360..2b936a7 100644 >> --- a/drivers/tty/serial/earlycon.c >> +++ b/drivers/tty/serial/earlycon.c >> @@ -17,6 +17,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> @@ -196,17 +197,29 @@ static int __init param_setup_earlycon(char *buf) >> } >> early_param("earlycon", param_setup_earlycon); >> >> -int __init of_setup_earlycon(unsigned long addr, >> +int __init of_setup_earlycon(const void *fdt, int offset, unsigned long addr, > > I would add iotype as a parameter instead, and then... > >> int (*setup)(struct earlycon_device *, const char *)) >> { >> int err; >> struct uart_port *port = &early_console_dev.port; >> + const __be32 *prop; >> >> port->iotype = UPIO_MEM; >> port->mapbase = addr; >> port->uartclk = BASE_BAUD * 16; >> port->membase = earlycon_map(addr, SZ_4K); >> >> + if (config_enabled(CONFIG_LIBFDT)) { >> + prop = fdt_getprop(fdt, offset, "reg-io-width", NULL); >> + if (prop) { >> + switch (be32_to_cpup(prop)) { >> + case 4: >> + port->iotype = UPIO_MEM32; >> + break; >> + } >> + } > > ...move this parsing into fdt.c where we parse the address. FWIW, all of of_setup_earlycon() should only be #ifdef CONFIG_OF_EARLY_FLATTREE Regards, Peter Hurley