On 04/12/2017 14:32, Ludovic Barre wrote: > From: Ludovic Barre <[email protected]> > > This adds low-level debug support on USART1 for STM32F4 > and STM32F7. Compiled via 'CONFIG_DEBUG_LL' and 'CONFIG_EARLY_PRINTK'. > Enabled via 'earlyprintk' in bootargs. > > Signed-off-by: Gerald Baeza <[email protected]>
Hi Ludovic, Please also add your sign-off here. Neil > --- > arch/arm/Kconfig.debug | 25 +++++++++++++++++++++++++ > arch/arm/include/debug/stm32.S | 41 +++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 66 insertions(+) > create mode 100644 arch/arm/include/debug/stm32.S > > diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug > index 17685e1..9469c58 100644 > --- a/arch/arm/Kconfig.debug > +++ b/arch/arm/Kconfig.debug > @@ -1140,6 +1140,26 @@ choice > > If unsure, say N. > > + config STM32F4_DEBUG_UART > + bool "Use STM32F4 UART for low-level debug" > + depends on ARCH_STM32 > + select DEBUG_STM32_UART > + help > + Say Y here if you want kernel low-level debugging support > + on STM32 based platforms. > + > + If unsure, say N. > + > + config STM32F7_DEBUG_UART > + bool "Use STM32F7 UART for low-level debug" > + depends on ARCH_STM32 > + select DEBUG_STM32_UART > + help > + Say Y here if you want kernel low-level debugging support > + on STM32 based platforms. > + > + If unsure, say N. > + > config TEGRA_DEBUG_UART_AUTO_ODMDATA > bool "Kernel low-level debugging messages via Tegra UART via > ODMDATA" > depends on ARCH_TEGRA > @@ -1424,6 +1444,10 @@ config DEBUG_STI_UART > bool > depends on ARCH_STI > > +config DEBUG_STM32_UART > + bool > + depends on ARCH_STM32 > + > config DEBUG_SIRFSOC_UART > bool > depends on ARCH_SIRF > @@ -1472,6 +1496,7 @@ config DEBUG_LL_INCLUDE > default "debug/s5pv210.S" if DEBUG_S5PV210_UART > default "debug/sirf.S" if DEBUG_SIRFSOC_UART > default "debug/sti.S" if DEBUG_STI_UART > + default "debug/stm32.S" if DEBUG_STM32_UART > default "debug/tegra.S" if DEBUG_TEGRA_UART > default "debug/ux500.S" if DEBUG_UX500_UART > default "debug/vexpress.S" if DEBUG_VEXPRESS_UART0_DETECT > diff --git a/arch/arm/include/debug/stm32.S b/arch/arm/include/debug/stm32.S > new file mode 100644 > index 0000000..4015257 > --- /dev/null > +++ b/arch/arm/include/debug/stm32.S > @@ -0,0 +1,41 @@ > +/* > + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved > + * Author: Gerald Baeza <[email protected]> > + * License terms: GNU General Public License (GPL), version 2 > + */ > + > +#define STM32_UART_BASE 0x40011000 /* USART1 */ > + > +#ifdef CONFIG_STM32F4_DEBUG_UART > +#define STM32_USART_SR_OFF 0x00 > +#define STM32_USART_TDR_OFF 0x04 > +#endif > + > +#ifdef CONFIG_STM32F7_DEBUG_UART > +#define STM32_USART_SR_OFF 0x1C > +#define STM32_USART_TDR_OFF 0x28 > +#endif > + > +#define STM32_USART_TC (1 << 6) /* Tx complete > */ > +#define STM32_USART_TXE (1 << 7) /* Tx data reg > empty */ > + > + .macro addruart, rp, rv, tmp > + ldr \rp, =STM32_UART_BASE @ physical base > + ldr \rv, =STM32_UART_BASE @ virt base /* NoMMU */ > + .endm > + > + .macro senduart,rd,rx > + strb \rd, [\rx, #STM32_USART_TDR_OFF] > + .endm > + > + .macro waituart,rd,rx > +1001: ldr \rd, [\rx, #(STM32_USART_SR_OFF)] @ Read Status > Register > + tst \rd, #STM32_USART_TXE @ TXE = 1 = tx empty > + beq 1001b > + .endm > + > + .macro busyuart,rd,rx > +1001: ldr \rd, [\rx, #(STM32_USART_SR_OFF)] @ Read Status > Register > + tst \rd, #STM32_USART_TC @ TC = 1 = tx complete > + beq 1001b > + .endm >
