serial: mfd: add more baud rates support
Add more baud rates support referring the baud_table[] defined
in drivers/char/tty_ioctl.c: 3000000/2000000/1000000/500000
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Alan Cox <alan.cox@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/serial/mfd.c b/drivers/serial/mfd.c
index ad35130..735799e 100644
--- a/drivers/serial/mfd.c
+++ b/drivers/serial/mfd.c
@@ -929,39 +929,52 @@
cval |= UART_LCR_EPAR;
/*
+ * The base clk is 50Mhz, and the baud rate come from:
+ * baud = 50M * MUL / (DIV * PS * DLAB)
+ *
* For those basic low baud rate we can get the direct
- * scalar from 2746800, like 115200 = 2746800/24, for those
- * higher baud rate, we have to handle them case by case,
- * but DIV reg is never touched as its default value 0x3d09
+ * scalar from 2746800, like 115200 = 2746800/24. For those
+ * higher baud rate, we handle them case by case, mainly by
+ * adjusting the MUL/PS registers, and DIV register is kept
+ * as default value 0x3d09 to make things simple
*/
baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
- quot = uart_get_divisor(port, baud);
+ quot = 1;
switch (baud) {
case 3500000:
mul = 0x3345;
ps = 0xC;
- quot = 1;
+ break;
+ case 3000000:
+ mul = 0x2EE0;
break;
case 2500000:
mul = 0x2710;
- ps = 0x10;
- quot = 1;
break;
- case 18432000:
+ case 2000000:
+ mul = 0x1F40;
+ break;
+ case 1843200:
mul = 0x2400;
- ps = 0x10;
- quot = 1;
break;
case 1500000:
- mul = 0x1D4C;
- ps = 0xc;
- quot = 1;
+ mul = 0x1770;
+ break;
+ case 1000000:
+ mul = 0xFA0;
+ break;
+ case 500000:
+ mul = 0x7D0;
break;
default:
- ;
+ /* Use uart_get_divisor to get quot for other baud rates */
+ quot = 0;
}
+ if (!quot)
+ quot = uart_get_divisor(port, baud);
+
if ((up->port.uartclk / quot) < (2400 * 16))
fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_1B;
else if ((up->port.uartclk / quot) < (230400 * 16))