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 <mans@xxxxxxxxx> > --- > 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] > + 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_8250 > diff --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. -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
