Author: stepan
Date: Fri Apr 22 03:45:11 2011
New Revision: 6538
URL: https://tracker.coreboot.org/trac/coreboot/changeset/6538
Log:
The UART divider should be calculated based on the base frequency
and baudrate, not hardcoded in addition to that.
Signed-off-by: Stefan Reinauer <stefan.reina...@coreboot.org>
Acked-by: Peter Stuge <pe...@stuge.se>
Modified:
trunk/src/console/uart8250_console.c
trunk/src/include/uart8250.h
trunk/src/lib/uart8250.c
trunk/src/mainboard/iwave/iWRainbowG6/Kconfig
Modified: trunk/src/console/uart8250_console.c
==============================================================================
--- trunk/src/console/uart8250_console.c Thu Apr 21 23:26:58 2011
(r6537)
+++ trunk/src/console/uart8250_console.c Fri Apr 22 03:45:11 2011
(r6538)
@@ -25,7 +25,13 @@
{
static const unsigned char div[8] = { 1, 2, 3, 6, 12, 24, 48, 96 };
int b_index = 0;
- unsigned int divisor = CONFIG_TTYS0_DIV;
+ /* TODO the divisor calculation is hard coded to standard UARTs. Some
+ * UARTs won't work with these values. This should be a property of the
+ * UART used, worst case a Kconfig variable. For now live with hard
+ * codes as the only devices that might be different are the iWave
+ * iRainbowG6 and the OXPCIe952 card (and the latter is memory mapped)
+ */
+ unsigned int divisor = 115200 / CONFIG_TTYS0_BAUD;
if (get_option(&b_index, "baud_rate") == 0) {
divisor = div[b_index];
Modified: trunk/src/include/uart8250.h
==============================================================================
--- trunk/src/include/uart8250.h Thu Apr 21 23:26:58 2011 (r6537)
+++ trunk/src/include/uart8250.h Fri Apr 22 03:45:11 2011 (r6538)
@@ -28,13 +28,9 @@
#ifndef CONFIG_TTYS0_BAUD
#define CONFIG_TTYS0_BAUD 115200
#endif
-
-#ifndef CONFIG_TTYS0_DIV
#if ((115200%CONFIG_TTYS0_BAUD) != 0)
#error Bad ttys0 baud rate
#endif
-#define CONFIG_TTYS0_DIV (115200/CONFIG_TTYS0_BAUD)
-#endif
/* Line Control Settings */
#ifndef CONFIG_TTYS0_LCS
Modified: trunk/src/lib/uart8250.c
==============================================================================
--- trunk/src/lib/uart8250.c Thu Apr 21 23:26:58 2011 (r6537)
+++ trunk/src/lib/uart8250.c Fri Apr 22 03:45:11 2011 (r6538)
@@ -88,6 +88,12 @@
#if defined(__PRE_RAM__) || defined(__SMM__)
void uart_init(void)
{
+ /* TODO the divisor calculation is hard coded to standard UARTs. Some
+ * UARTs won't work with these values. This should be a property of the
+ * UART used, worst case a Kconfig variable. For now live with hard
+ * codes as the only devices that might be different are the iWave
+ * iRainbowG6 and the OXPCIe952 card (and the latter is memory mapped)
+ */
#if CONFIG_USE_OPTION_TABLE && !defined(__SMM__)
static const unsigned char divisor[] = { 1, 2, 3, 6, 12, 24, 48, 96 };
unsigned ttys0_div, ttys0_index;
@@ -97,7 +103,7 @@
uart8250_init(CONFIG_TTYS0_BASE, ttys0_div);
#else
- uart8250_init(CONFIG_TTYS0_BASE, CONFIG_TTYS0_DIV);
+ uart8250_init(CONFIG_TTYS0_BASE, (115200 / CONFIG_TTYS0_BAUD));
#endif
}
#endif
Modified: trunk/src/mainboard/iwave/iWRainbowG6/Kconfig
==============================================================================
--- trunk/src/mainboard/iwave/iWRainbowG6/Kconfig Thu Apr 21 23:26:58
2011 (r6537)
+++ trunk/src/mainboard/iwave/iWRainbowG6/Kconfig Fri Apr 22 03:45:11
2011 (r6538)
@@ -37,9 +37,7 @@
int
default 10
-# WTF, is this 19200?
-config TTYS0_DIV
- int
- default 6
+# This mainboard might have a higher clocked UART or might not be able to run
+# serial output at 115200 baud
endif
--
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