This function is made available to board which want to display a message
when a panic() occurs before the console is set up. This would otherwise
result in a silent hang or reboot.
Boards should call tegra_pre_console_panic() and pass the UARTs which
are available and safe for a message, as well as the selected clock and
serial multiplier values. Defaults are available as
CONFIG_DEFAULT_NS16550_CLK and CONFIG_DEFAULT_NS16550_MULT.
Signed-off-by: Simon Glass <s...@chromium.org>
---
arch/arm/cpu/armv7/tegra2/board.c | 48 ++++++++++++++++++++++++++++++
arch/arm/include/asm/arch-tegra2/board.h | 13 ++++++++
include/configs/tegra2-common.h | 4 ++
3 files changed, 65 insertions(+), 0 deletions(-)
diff --git a/arch/arm/cpu/armv7/tegra2/board.c
b/arch/arm/cpu/armv7/tegra2/board.c
index c9a7520..54963d0 100644
--- a/arch/arm/cpu/armv7/tegra2/board.c
+++ b/arch/arm/cpu/armv7/tegra2/board.c
@@ -22,6 +22,7 @@
*/
#include <common.h>
+#include <ns16550.h>
#include <asm/io.h>
#include "ap20.h"
#include <asm/arch/board.h>
@@ -137,3 +138,50 @@ void enable_caches(void)
dcache_enable();
}
#endif
+
+/*
+ * Possible UART locations: we ignore UARTC at 0x70006200 and UARTE at
+ * 0x70006400, since we don't have code to init them
+ */
+static const u32 uart_reg_addr[TEGRA_UART_COUNT] = {
+ NV_PA_APB_UARTA_BASE,
+ NV_PA_APB_UARTB_BASE,
+ 0,
+ NV_PA_APB_UARTD_BASE,
+};
+
+void tegra_pre_console_panic(int uart_ids, unsigned clock_freq,
+ unsigned multiplier, const char *str)
+{
+ int baudrate, divisor;
+ int i;
+
+ /* Enable all permitted UARTs */
+ tegra_setup_uarts(uart_ids);
+
+ /*
+ * Now send the string out all the selected UARTs. We don't try all
+ * possible configurations, but this could be added if required.
+ */
+ baudrate = CONFIG_BAUDRATE;
+ divisor = (clock_freq + (baudrate * (multiplier / 2))) /
+ (multiplier * baudrate);
+
+ for (i = 0; i < TEGRA_UART_COUNT; i++) {
+ if (uart_ids & (1 << i)) {
+ NS16550_t regs = (NS16550_t)uart_reg_addr[i];
+ const char *s;
+
+ if (!regs)
+ continue;
+ NS16550_init(regs, divisor);
+ for (s = str; *s; s++) {
+ NS16550_putc(regs, *s);
+ if (*s == '\n')
+ NS16550_putc(regs, '\r');
+ }
+ NS16550_putc(regs, '\n');
+ NS16550_putc(regs, '\r');
+ }
+ }
+}
diff --git a/arch/arm/include/asm/arch-tegra2/board.h
b/arch/arm/include/asm/arch-tegra2/board.h
index fb88517..fd2489f 100644
--- a/arch/arm/include/asm/arch-tegra2/board.h
+++ b/arch/arm/include/asm/arch-tegra2/board.h
@@ -41,6 +41,19 @@ enum {
*/
void tegra_setup_uarts(int uart_ids);
+/**
+ * Display a panic message on selected UARTs.
+ *
+ * This is called when we have no console yet but have hit a panic(). It
+ * is normally called from board_pre_console_panic(), which passes in the
+ * UARTs that we are permitted to output to.
+ *
+ * We display a message on each UART in the hope that one will reach the
+ * user.
+ */
+void tegra_pre_console_panic(int uart_ids, unsigned clock_freq,
+ unsigned multiplier, const char *str);
+
/* Setup UARTs for the board according to the selected config */
void board_init_uart_f(void);
diff --git a/include/configs/tegra2-common.h b/include/configs/tegra2-common.h
index 837f859..14d7602 100644
--- a/include/configs/tegra2-common.h
+++ b/include/configs/tegra2-common.h
@@ -84,6 +84,10 @@
#define CONFIG_SYS_BAUDRATE_TABLE {4800, 9600, 19200, 38400, 57600,\
115200}
+/* Default serial clock and multiplier */
+#define CONFIG_DEFAULT_NS16550_CLK V_NS16550_CLK
+#define CONFIG_DEFAULT_NS16550_MULT 16
+
/*
* This parameter affects a TXFILLTUNING field that controls how much data is
* sent to the latency fifo before it is sent to the wire. Without this
--
1.7.7.3
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