Add xtensa semihosting driver.
It can't use regular semihosting driver as Xtensa's has it's own semihosting ABI.
Note that semihosting supports puts in serial but I never managed to get it work, so it's putc only for now.
Signed-off-by: Jiaxun Yang jiaxun.yang@flygoat.com --- drivers/serial/Kconfig | 18 ++++++- drivers/serial/Makefile | 1 + drivers/serial/serial_xtensa_semihosting.c | 79 ++++++++++++++++++++++++++++++ 3 files changed, 97 insertions(+), 1 deletion(-)
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 1fe4607598eb..3a1e5a6f2877 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -501,6 +501,15 @@ config DEBUG_UART_MT7620 driver will be available until the real driver model serial is running.
+config DEBUG_UART_XTENSA_SEMIHOSTING + bool "Xtensa semihosting" + depends on XTENSA_SEMIHOSTING_SERIAL + help + Select this to enable the debug UART using the Xtensa semihosting driver. + This provides basic serial output from the console without needing to + start up driver model. The driver will be available until the real + driver model serial is running. + endchoice
config DEBUG_UART_BASE @@ -936,7 +945,6 @@ config SH_SCIF_CLK_FREQ config SEMIHOSTING_SERIAL bool "Semihosting UART support" depends on SEMIHOSTING && !SERIAL_RX_BUFFER - imply SERIAL_PUTS help Select this to enable a serial UART using semihosting. Special halt instructions will be issued which an external debugger (such as a @@ -1115,6 +1123,14 @@ config XEN_SERIAL If built without DM support, then requires Xen to be built with CONFIG_VERBOSE_DEBUG.
+config XTENSA_SEMIHOSTING_SERIAL + bool "Xtensa Semihosting UART support" + depends on DM_SERIAL + depends on XTENSA_SEMIHOSTING + imply SERIAL_PUTS + help + Select this to enable a serial UART using Xtensa semihosting. + choice prompt "Console port" default 8xx_CONS_SMC1 diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index dbe598b74064..78810f98367c 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -60,6 +60,7 @@ obj-$(CONFIG_MT7620_SERIAL) += serial_mt7620.o obj-$(CONFIG_HTIF_CONSOLE) += serial_htif.o obj-$(CONFIG_SIFIVE_SERIAL) += serial_sifive.o obj-$(CONFIG_XEN_SERIAL) += serial_xen.o +obj-$(CONFIG_XTENSA_SEMIHOSTING_SERIAL) += serial_xtensa_semihosting.o obj-$(CONFIG_S5P4418_PL011_SERIAL) += serial_s5p4418_pl011.o
ifndef CONFIG_SPL_BUILD diff --git a/drivers/serial/serial_xtensa_semihosting.c b/drivers/serial/serial_xtensa_semihosting.c new file mode 100644 index 000000000000..1bf3c18537e7 --- /dev/null +++ b/drivers/serial/serial_xtensa_semihosting.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2024 Jiaxun Yang jiaxun.yang@flygoat.com + */ + +#include <dm.h> +#include <malloc.h> +#include <serial.h> + +#include <asm/platform/simcall.h> + +/** + * struct simc_serial_priv - Semihosting serial private data + * @counter: Counter used to fake pending every other call + */ +struct simc_serial_priv { + unsigned int counter; +}; + +static int simc_serial_getc(struct udevice *dev) +{ + char ch = 0; + + simc_read(0, &ch, sizeof(ch)); + + return ch; +} + +static int simc_serial_putc(struct udevice *dev, const char ch) +{ + char str[2] = {0}; + + str[0] = ch; + simc_write(1, str, 1); + + return 0; +} + +static int simc_serial_pending(struct udevice *dev, bool input) +{ + struct simc_serial_priv *priv = dev_get_priv(dev); + + if (input) + return priv->counter++ & 1; + return false; +} + +static const struct dm_serial_ops simc_serial_ops = { + .putc = simc_serial_putc, + .getc = simc_serial_getc, + .pending = simc_serial_pending, +}; + +U_BOOT_DRIVER(simc_serial) = { + .name = "serial_xtensa_semihosting", + .id = UCLASS_SERIAL, + .priv_auto = sizeof(struct simc_serial_priv), + .ops = &simc_serial_ops, + .flags = DM_FLAG_PRE_RELOC, +}; + +U_BOOT_DRVINFO(simc_serial) = { + .name = "serial_xtensa_semihosting", +}; + +#if CONFIG_IS_ENABLED(DEBUG_UART_XTENSA_SEMIHOSTING) +#include <debug_uart.h> + +static inline void _debug_uart_init(void) +{ +} + +static inline void _debug_uart_putc(int c) +{ + simc_serial_putc(NULL, c); +} + +DEBUG_UART_FUNCS +#endif