From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= Subject: Re: [RESEND][PATCH] ARM: debug: add support for Palmchip 16550-like UART Date: Wed, 04 Nov 2015 15:47:26 +0000 Message-ID: References: <1445950678-16097-1-git-send-email-mans@mansr.com> <563A26B8.9080405@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <563A26B8.9080405@free.fr> (Mason's message of "Wed, 4 Nov 2015 16:39:36 +0100") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Mason Cc: Russell King , linux-serial , Linux ARM List-Id: linux-serial@vger.kernel.org Mason writes: > On 27/10/2015 13:57, Mans Rullgard wrote: > >> Some SoCs have a Palmchip UART with a non-standard register layout. >> This allows the debug console to work with these. >> = >> Signed-off-by: Mans Rullgard >> --- >> arch/arm/Kconfig.debug | 8 ++++++++ >> arch/arm/include/debug/8250.S | 12 ++++++++++++ >> 2 files changed, 20 insertions(+) >> = >> diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug >> index 0cfd7f9..9039fff 100644 >> --- a/arch/arm/Kconfig.debug >> +++ b/arch/arm/Kconfig.debug >> @@ -1597,6 +1597,14 @@ config DEBUG_UART_8250_WORD >> DEBUG_BCM_KONA_UART || DEBUG_RK32_UART2 || \ >> DEBUG_BRCMSTB_UART >> = >> +config DEBUG_UART_8250_PALMCHIP >> + bool "8250 UART is Palmchip variant" >> + depends on DEBUG_LL_UART_8250 || DEBUG_UART_8250 > > I am 100% clueless about the UART sequence in Linux. > > There's earlyprintk, the boot console (polled?), the "full-blown" > console (with IRQs)... > > If I want earlyprintk, I have to enable DEBUG_LL (?) so I'll have > DEBUG_LL_UART_8250, right? There's no way to pick DEBUG_UART_8250 > in menuconfig, is there? > > So I picked the following options: > > CONFIG_DEBUG_LL=3Dy > # CONFIG_DEBUG_ICEDCC is not set > # CONFIG_DEBUG_SEMIHOSTING is not set > CONFIG_DEBUG_LL_UART_8250=3Dy > # CONFIG_DEBUG_LL_UART_PL01X is not set > CONFIG_DEBUG_LL_INCLUDE=3D"debug/8250.S" > # CONFIG_DEBUG_UART_8250 is not set > # CONFIG_DEBUG_UART_BCM63XX is not set > CONFIG_DEBUG_UART_PHYS=3D0x10700 > CONFIG_DEBUG_UART_VIRT=3D0xf0010700 > CONFIG_DEBUG_UART_8250_SHIFT=3D2 > CONFIG_DEBUG_UART_8250_WORD=3Dy > CONFIG_DEBUG_UART_8250_PALMCHIP=3Dy > # CONFIG_DEBUG_UART_8250_FLOW_CONTROL is not set > CONFIG_DEBUG_UNCOMPRESS=3Dy > CONFIG_UNCOMPRESS_INCLUDE=3D"debug/uncompress.h" > CONFIG_EARLY_PRINTK=3Dy Those are the settings I use. > I suppose I have to provide DEBUG_UART_PHYS because it needs > the address before it can parse the DT? But how am I supposed > to know the virtual address? Isn't that from iomap(UART_PHYS)? The decompression code and early setup don't have that luxury. > 'make' wouldn't let me proceed unless I gave something... > > Then I have to add earlyprintk to my boot command line, right? > Do I need to specify more than that? Just earlyprintk without any parameters works. -- = M=E5ns Rullg=E5rd mans@mansr.com