diff options
| author | Gerald Baeza <gerald.baeza@st.com> | 2017-07-27 19:50:20 +0300 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2018-11-12 21:20:41 +0300 |
| commit | d88bb418b7cc0525254cb1723a40b7b4133bad01 (patch) | |
| tree | 824e07c884530059fcd56ee8a63c4eaf6715d20e /arch/arm/include/debug | |
| parent | ccda4af0f4b92f7b4c308d3acc262f4a7e3affad (diff) | |
| download | linux-d88bb418b7cc0525254cb1723a40b7b4133bad01.tar.xz | |
ARM: stm32: debug: add low-level debug support
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 <gerald.baeza@st.com>
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'arch/arm/include/debug')
| -rw-r--r-- | arch/arm/include/debug/stm32.S | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/arm/include/debug/stm32.S b/arch/arm/include/debug/stm32.S new file mode 100644 index 000000000000..1abb32f685fd --- /dev/null +++ b/arch/arm/include/debug/stm32.S @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) STMicroelectronics SA 2017 - All Rights Reserved + * Author: Gerald Baeza <gerald.baeza@st.com> for STMicroelectronics. + */ + +#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 |