From: Wolfgang Denk <wd@pollux.(none)>
Date: Sun, 25 Sep 2005 14:50:33 +0000 (+0200)
Subject: Fix au1x00_serial baud rate calculation:
X-Git-Tag: LABEL_2006_03_12_0025~145
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=7a22cd535b67e89af88190cd5143ba53f502f064;p=oweals%2Fu-boot.git

Fix au1x00_serial baud rate calculation:
remove hardcoded cpu clock divisor and use register instead;
round up instead of truncate
Patch by Andrew Dyer, 15 Feb 2005
---

diff --git a/CHANGELOG b/CHANGELOG
index 9444f4d262..e189bbb0ad 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -2,8 +2,13 @@
 Changes for U-Boot 1.1.4:
 ======================================================================
 
+* Fix au1x00_serial baud rate calculation:
+  remove hardcoded cpu clock divisor and use register instead;
+  round up instead of truncate
+  Patch by Andrew Dyer, 15 Feb 2005
+
 * Add Xilinx Spartan3 family FPGA support
-  Patch by Kurt Stremerch, 14 February 2005
+  Patch by Kurt Stremerch, 14 Feb 2005
 
 * Fix drivers/cfi_flash.c: use info->reset_cmd instead of FLASH_CMD_RESET
   Patch by Zachary Landau, 11 Feb 2005
diff --git a/cpu/mips/au1x00_serial.c b/cpu/mips/au1x00_serial.c
index ac75da591f..42c668ee3d 100644
--- a/cpu/mips/au1x00_serial.c
+++ b/cpu/mips/au1x00_serial.c
@@ -70,9 +70,21 @@ void serial_setbrg (void)
 {
 	volatile u32 *uart_clk = (volatile u32*)(UART0_ADDR+UART_CLK);
 	volatile u32 *uart_lcr = (volatile u32*)(UART0_ADDR+UART_LCR);
+	volatile u32 *sys_powerctrl = (u32 *)SYS_POWERCTRL;
+	int sd;
+	int divisorx2;
 
-	/* Set baudrate - FIXME for bus speeds != CPU/2 */
-	*uart_clk = ((CFG_HZ/(CONFIG_BAUDRATE * 64)));
+	/* sd is system clock divisor			*/
+	/* see section 10.4.5 in au1550 datasheet	*/
+	sd = (*sys_powerctrl & 0x03) + 2;
+
+	/* calulate 2x baudrate and round */
+	divisorx2 = ((CFG_HZ/(sd * 16 * CONFIG_BAUDRATE)));
+
+	if (divisorx2 & 0x01)
+		divisorx2 = divisorx2 + 1;
+
+	*uart_clk = divisorx2 / 2;
 
 	/* Set parity, stop bits and word length to 8N1 */
 	*uart_lcr = UART_LCR_WLEN8;