[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v1 2/5] xen/arm: Add NXP LINFlexD UART early printk support
On 11/09/2024 00:58, Julien Grall wrote: > Hi, > > On 10/09/2024 15:34, Andrei Cherechesu (OSS) wrote: >> From: Andrei Cherechesu <andrei.cherechesu@xxxxxxx> >> >> This adds support for early printk debug via the NXP LINFlexD >> UART controller. >> >> Signed-off-by: Andrei Cherechesu <andrei.cherechesu@xxxxxxx> >> Signed-off-by: Peter van der Perk <peter.vander.perk@xxxxxxx> >> --- >> xen/arch/arm/Kconfig.debug | 14 +++++++ >> xen/arch/arm/arm64/debug-linflex.inc | 58 ++++++++++++++++++++++++++++ >> 2 files changed, 72 insertions(+) >> create mode 100644 xen/arch/arm/arm64/debug-linflex.inc >> >> diff --git a/xen/arch/arm/Kconfig.debug b/xen/arch/arm/Kconfig.debug >> index eec860e88e..a309f67f90 100644 >> --- a/xen/arch/arm/Kconfig.debug >> +++ b/xen/arch/arm/Kconfig.debug >> @@ -68,6 +68,16 @@ choice >> provide the parameters for the i.MX LPUART rather than >> selecting one of the platform specific options below if >> you know the parameters for the port. >> + config EARLY_UART_CHOICE_LINFLEX >> + select EARLY_UART_LINFLEX >> + depends on ARM_64 >> + bool "Early printk via NXP LINFlexD UART" >> + help >> + Say Y here if you wish the early printk to direct their >> + output to an NXP LINFlexD UART. You can use this option to >> + provide the parameters for the NXP LINFlexD UART rather than >> + selecting one of the platform specific options below if >> + you know the parameters for the port. >> config EARLY_UART_CHOICE_MESON >> select EARLY_UART_MESON >> depends on ARM_64 >> @@ -199,6 +209,9 @@ config EARLY_UART_EXYNOS4210 >> config EARLY_UART_IMX_LPUART >> select EARLY_PRINTK >> bool >> +config EARLY_UART_LINFLEX >> + select EARLY_PRINTK >> + bool >> config EARLY_UART_MESON >> select EARLY_PRINTK >> bool >> @@ -304,6 +317,7 @@ config EARLY_PRINTK_INC >> default "debug-cadence.inc" if EARLY_UART_CADENCE >> default "debug-exynos4210.inc" if EARLY_UART_EXYNOS4210 >> default "debug-imx-lpuart.inc" if EARLY_UART_IMX_LPUART >> + default "debug-linflex.inc" if EARLY_UART_LINFLEX >> default "debug-meson.inc" if EARLY_UART_MESON >> default "debug-mvebu.inc" if EARLY_UART_MVEBU >> default "debug-pl011.inc" if EARLY_UART_PL011 >> diff --git a/xen/arch/arm/arm64/debug-linflex.inc >> b/xen/arch/arm/arm64/debug-linflex.inc >> new file mode 100644 >> index 0000000000..6ed704e104 >> --- /dev/null >> +++ b/xen/arch/arm/arm64/debug-linflex.inc >> @@ -0,0 +1,58 @@ >> +/* SPDX-License-Identifier: GPL-2.0 */ > > GPL-2.0 is deprecated and replaced by GPL-2.0-only. Will fix in v2. > >> +/* >> + * xen/arch/arm/arm64/debug-linflex.inc >> + * >> + * NXP LINFlexD UART specific debug code >> + * >> + * Andrei Cherechesu <andrei.cherechesu@xxxxxxx> >> + * Copyright 2018, 2021, 2023-2024 NXP >> + */ >> + >> +#include <asm/asm_defns.h> >> +#include <asm/linflex-uart.h> >> + >> +/* >> + * wait LINFlexD UART to be ready to transmit >> + * xb: register which contains the UART base address >> + * c: scratch register number >> + */ >> +.macro early_uart_ready xb, c >> + ldr w\c, [\xb, #UARTCR] /* <= Control Register */ >> + and w\c, w\c, #UARTCR_TFBM /* Check Buffer/FIFO (0/1) Mode */ >> + cbz w\c, 2f /* Buffer Mode => return */ >> +1: >> + ldrb w\c, [\xb, #UARTSR] /* <= Status Register */ >> + tst w\c, #UARTSR_DTFTFF /* FIFO Mode => Check DTF bit */ >> + b.ne 1b >> +2: >> +.endm >> + >> +/* >> + * LINFlexD UART transmit character >> + * xb: register which contains the UART base address >> + * wt: register which contains the character to transmit >> + */ >> +.macro early_uart_transmit xb, wt >> + strb \wt, [\xb, #BDRL] >> + >> + ldr \wt, [\xb, #UARTCR] /* <= Control Register */ >> + and \wt, \wt, #UARTCR_TFBM /* Check Buffer/FIFO (0/1) Mode */ >> + cbnz \wt, 2f /* FIFO Mode => goto exit */ >> + >> +3: /* Buffer Mode */ >> + ldrb \wt, [\xb, #UARTSR] /* <= Status Register */ >> + and \wt, \wt, #UARTSR_DTFTFF /* Check Transmission Completed */ >> + cbz \wt, 3b >> + >> + ldr \wt, [\xb, #UARTSR] /* <= Status Register */ >> + orr \wt, \wt, #UARTSR_DTFTFF /* Clear DTF bit */ >> + str \wt, [\xb, #UARTSR] >> +2: >> +.endm >> + >> +/* >> + * Local variables: >> + * mode: ASM >> + * indent-tabs-mode: nil >> + * End: >> + */ >> \ No newline at end of file > > The file should end with a newline. > Will fix in v2. > I haven't looked at the specifics of the UART. But the code integration in > Xen LGTM. So with the two comments addressed: > > Acked-by: Julien Grall <jgrall@xxxxxxxxxx> > > Cheers, > Thanks for the review! Regards, Andrei C
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