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Fix au1x00_serial baud rate calculation:

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remove hardcoded cpu clock divisor and use register instead;
round up instead of truncate
Patch by Andrew Dyer, 15 Feb 2005
This commit is contained in:
Wolfgang Denk
2005-09-25 16:50:33 +02:00
parent 875c78934e
commit 7a22cd535b
2 changed files with 20 additions and 3 deletions
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16
cpu/mips/au1x00_serial.c
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@@ -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;