This adds a new CONFIG_DEBUG_SERIAL define so that people can figure out
if/when their serial port is hitting errors.
Signed-off-by: Mike Frysinger <[EMAIL PROTECTED]>
---
cpu/blackfin/serial.c | 57 +++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 48 insertions(+), 9 deletions(-)
diff --git a/cpu/blackfin/serial.c b/cpu/blackfin/serial.c
index 0dfee51..f538bba 100644
--- a/cpu/blackfin/serial.c
+++ b/cpu/blackfin/serial.c
@@ -35,6 +35,29 @@
#include "serial.h"
+#ifdef CONFIG_DEBUG_SERIAL
+uint16_t cached_lsr[256];
+uint16_t cached_rbr[256];
+size_t cache_count;
+#endif
+
+/* The LSR is read-to-clear on some parts, so we have to make sure status
+ * bits aren't inadvertently lost when doing various tests.
+ */
+static uint16_t uart_lsr_save;
+static uint16_t uart_lsr_read(void)
+{
+ uint16_t lsr = *pUART_LSR;
+ uart_lsr_save |= (lsr & (OE|PE|FE|BI));
+ return lsr | uart_lsr_save;
+}
+/* Just do the clear for everyone since it can't hurt. */
+static void uart_lsr_clear(void)
+{
+ uart_lsr_save = 0;
+ *pUART_LSR |= -1;
+}
+
/* Symbol for our assembly to call. */
void serial_set_baud(uint32_t baud)
{
@@ -61,6 +84,12 @@ int serial_init(void)
{
serial_initialize();
serial_setbrg();
+ uart_lsr_clear();
+#ifdef CONFIG_DEBUG_SERIAL
+ cache_count = 0;
+ memset(cached_lsr, 0x00, sizeof(cached_lsr));
+ memset(cached_rbr, 0x00, sizeof(cached_rbr));
+#endif
return 0;
}
@@ -73,7 +102,7 @@ void serial_putc(const char c)
WATCHDOG_RESET();
/* wait for the hardware fifo to clear up */
- while (!(*pUART_LSR & THRE))
+ while (!(uart_lsr_read() & THRE))
continue;
/* queue the character for transmission */
@@ -83,14 +112,14 @@ void serial_putc(const char c)
WATCHDOG_RESET();
/* wait for the byte to be shifted over the line */
- while (!(*pUART_LSR & TEMT))
+ while (!(uart_lsr_read() & TEMT))
continue;
}
int serial_tstc(void)
{
WATCHDOG_RESET();
- return (*pUART_LSR & DR) ? 1 : 0;
+ return (uart_lsr_read() & DR) ? 1 : 0;
}
int serial_getc(void)
@@ -102,15 +131,25 @@ int serial_getc(void)
continue;
/* clear the status and grab the new byte */
- uart_lsr_val = *pUART_LSR;
+ uart_lsr_val = uart_lsr_read();
uart_rbr_val = *pUART_RBR;
+#ifdef CONFIG_DEBUG_SERIAL
+ cached_lsr[cache_count] = uart_lsr_val;
+ cached_rbr[cache_count] = uart_rbr_val;
+ cache_count = (cache_count + 1) % ARRAY_SIZE(cached_lsr);
+#endif
+
if (uart_lsr_val & (OE|PE|FE|BI)) {
- /* Some parts are read-to-clear while others are
- * write-to-clear. Just do the write for everyone
- * since it cant hurt (other than code size).
- */
- *pUART_LSR = (OE|PE|FE|BI);
+#ifdef CONFIG_DEBUG_SERIAL
+ printf("\n[SERIAL ERROR]\n");
+ do {
+ --cache_count;
+ printf("\t%3i: RBR=0x%02x LSR=0x%02x\n", cache_count,
+ cached_rbr[cache_count],
cached_lsr[cache_count]);
+ } while (cache_count > 0);
+#endif
+ uart_lsr_clear();
return -1;
}
--
1.5.4.2
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