serial: sh: Add DEBUG_UART support
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>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index bb50832..10d07da 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -415,6 +415,14 @@
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 c3e3f25..e08bdca 100644
--- a/drivers/serial/serial_sh.c
+++ b/drivers/serial/serial_sh.c
@@ -249,9 +249,40 @@
#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 @@
# 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 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 @@
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