Add support for debug output very early during boot using the DEBUG_UART mechanism. This uses a static fixed UART port configuration selected via Kconfig options and dedicated print functions from debug_uart.h. This is useful e.g. when debugging problems so early during boot, that not even the DM is initialized at that point, and thus DM_SERIAL is not available either.
This functionality is disabled by default. To activate it, define the following Kconfig options and select SCIF type using CFG_SCI/CFG_SCIF_A/ CFG_HSCIF/<nothing for regular SCIF>:
CONFIG_DEBUG_UART=y CONFIG_DEBUG_UART_SCIF=y CONFIG_DEBUG_UART_BASE=0xe6540000 CONFIG_DEBUG_UART_CLOCK=24000000
The later two options define the SCIF physical base address and SCIF input clock in Hz. Optionally, to validate DEBUG_UART works, enable the following as well to get early serial output message by default:
CONFIG_DEBUG_UART_ANNOUNCE=y
Signed-off-by: Marek Vasut marek.vasut+renesas@mailbox.org --- Cc: Samuel Holland samuel@sholland.org Cc: Sean Anderson sean.anderson@seco.com Cc: Simon Glass sjg@chromium.org --- drivers/serial/Kconfig | 8 ++++ drivers/serial/serial_sh.c | 85 +++++++++++++++++++++++++++----------- 2 files changed, 68 insertions(+), 25 deletions(-)
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index bb5083201b3..10d07daf277 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -415,6 +415,14 @@ config DEBUG_UART_SEMIHOSTING start up driver model. The driver will be available until the real driver model serial is running.
+config DEBUG_UART_SCIF + bool "Renesas SCIF UART" + depends on SH || ARCH_RMOBILE + help + Select this to enable a debug UART using the serial_sh driver. You + will need to provide parameters to make this work. The driver will + be available until the real driver-model serial is running. + config DEBUG_UART_SIFIVE bool "SiFive UART" depends on SIFIVE_SERIAL diff --git a/drivers/serial/serial_sh.c b/drivers/serial/serial_sh.c index c3e3f257c65..e08bdcadc9c 100644 --- a/drivers/serial/serial_sh.c +++ b/drivers/serial/serial_sh.c @@ -249,9 +249,40 @@ U_BOOT_DRIVER(serial_sh) = { #endif .priv_auto = sizeof(struct uart_port), }; +#endif + +#if !CONFIG_IS_ENABLED(DM_SERIAL) || IS_ENABLED(CONFIG_DEBUG_UART_SCIF)
-#else /* CONFIG_DM_SERIAL */ +#if defined(CFG_SCIF_A) + #define SCIF_BASE_PORT PORT_SCIFA +#elif defined(CFG_SCI) + #define SCIF_BASE_PORT PORT_SCI +#else + #define SCIF_BASE_PORT PORT_SCIF +#endif + +static void sh_serial_init_nodm(struct uart_port *port) +{ + sh_serial_init_generic(port); + serial_setbrg(); +} + +static void sh_serial_putc_nondm(struct uart_port *port, const char c) +{ + if (c == '\n') { + while (1) { + if (serial_raw_putc(port, '\r') != -EAGAIN) + break; + } + } + while (1) { + if (serial_raw_putc(port, c) != -EAGAIN) + break; + } +} +#endif
+#if !CONFIG_IS_ENABLED(DM_SERIAL) #if defined(CONFIG_CONS_SCIF0) # define SCIF_BASE SCIF0_BASE #elif defined(CONFIG_CONS_SCIF1) @@ -274,14 +305,6 @@ U_BOOT_DRIVER(serial_sh) = { # error "Default SCIF doesn't set....." #endif
-#if defined(CFG_SCIF_A) - #define SCIF_BASE_PORT PORT_SCIFA -#elif defined(CFG_SCI) - #define SCIF_BASE_PORT PORT_SCI -#else - #define SCIF_BASE_PORT PORT_SCIF -#endif - static struct uart_port sh_sci = { .membase = (unsigned char *)SCIF_BASE, .mapbase = SCIF_BASE, @@ -301,28 +324,14 @@ static void sh_serial_setbrg(void)
static int sh_serial_init(void) { - struct uart_port *port = &sh_sci; - - sh_serial_init_generic(port); - serial_setbrg(); + sh_serial_init_nodm(&sh_sci);
return 0; }
static void sh_serial_putc(const char c) { - struct uart_port *port = &sh_sci; - - if (c == '\n') { - while (1) { - if (serial_raw_putc(port, '\r') != -EAGAIN) - break; - } - } - while (1) { - if (serial_raw_putc(port, c) != -EAGAIN) - break; - } + sh_serial_putc_nondm(&sh_sci, c); }
static int sh_serial_tstc(void) @@ -367,3 +376,29 @@ __weak struct serial_device *default_serial_console(void) return &sh_serial_drv; } #endif /* CONFIG_DM_SERIAL */ + +#ifdef CONFIG_DEBUG_UART_SCIF +#include <debug_uart.h> + +static struct uart_port debug_uart_sci = { + .membase = (unsigned char *)CONFIG_DEBUG_UART_BASE, + .mapbase = CONFIG_DEBUG_UART_BASE, + .type = SCIF_BASE_PORT, +#ifdef CFG_SCIF_USE_EXT_CLK + .clk_mode = EXT_CLK, +#endif +}; + +static inline void _debug_uart_init(void) +{ + sh_serial_init_nodm(&debug_uart_sci); +} + +static inline void _debug_uart_putc(int c) +{ + sh_serial_putc_nondm(&debug_uart_sci, c); +} + +DEBUG_UART_FUNCS + +#endif