[RESEND][PATCH] ARM: debug: add support for Palmchip 16550-like UART
From: Mason <hidden>
Date: 2015-11-04 15:39:36
Also in:
linux-serial
On 27/10/2015 13:57, Mans Rullgard wrote:
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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 <redacted> --- 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=y # CONFIG_DEBUG_ICEDCC is not set # CONFIG_DEBUG_SEMIHOSTING is not set CONFIG_DEBUG_LL_UART_8250=y # CONFIG_DEBUG_LL_UART_PL01X is not set CONFIG_DEBUG_LL_INCLUDE="debug/8250.S" # CONFIG_DEBUG_UART_8250 is not set # CONFIG_DEBUG_UART_BCM63XX is not set CONFIG_DEBUG_UART_PHYS=0x10700 CONFIG_DEBUG_UART_VIRT=0xf0010700 CONFIG_DEBUG_UART_8250_SHIFT=2 CONFIG_DEBUG_UART_8250_WORD=y CONFIG_DEBUG_UART_8250_PALMCHIP=y # CONFIG_DEBUG_UART_8250_FLOW_CONTROL is not set CONFIG_DEBUG_UNCOMPRESS=y CONFIG_UNCOMPRESS_INCLUDE="debug/uncompress.h" CONFIG_EARLY_PRINTK=y 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)? '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? According to the documentation, earlyprintk= [X86,SH,BLACKFIN,ARM,M68k] earlyprintk=vga earlyprintk=efi earlyprintk=xen earlyprintk=serial[,ttySn[,baudrate]] earlyprintk=serial[,0x...[,baudrate]] earlyprintk=ttySn[,baudrate] earlyprintk=dbgp[debugController#] earlyprintk=pciserial,bus:device.function[,baudrate]
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+ help + Palmchip provides a UART implementation compatible with 16550 + except for having a different register layout. Say Y here if + the debug UART is of this type. + config DEBUG_UART_8250_FLOW_CONTROL bool "Enable flow control for 8250 UART" depends on DEBUG_LL_UART_8250 || DEBUG_UART_8250diff --git a/arch/arm/include/debug/8250.S b/arch/arm/include/debug/8250.S index 7f7446f..2332f40 100644 --- a/arch/arm/include/debug/8250.S +++ b/arch/arm/include/debug/8250.S@@ -9,6 +9,18 @@ */ #include <linux/serial_reg.h> +#ifdef CONFIG_DEBUG_UART_8250_PALMCHIP + +#undef UART_TX +#undef UART_LSR +#undef UART_MSR + +#define UART_TX 1 +#define UART_LSR 7 +#define UART_MSR 8 + +#endif + .macro addruart, rp, rv, tmp ldr \rp, =CONFIG_DEBUG_UART_PHYS ldr \rv, =CONFIG_DEBUG_UART_VIRT
Regards.