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Subject[PATCH 6/6] serial: mfd: adjust the baud rate setting
Date
From: Feng Tang <feng.tang@intel.com>

Previous baud rate setting code only has been tested with 3.5M/9600/
115200/230400/460800 bps, and recently we got a 3M bps device to test,
which needs to modify current MUL register setting, and with this
patch 2.5M/2M/1.5M/1M/0.5M should also work as they just use a MUL
value scale down from 3M's.

Also got some reference register setting from silicon guys for
different baud rates, which tries to keep the pre-scalar register value
to 16.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/serial/mfd.c | 24 ++++++++----------------
1 files changed, 8 insertions(+), 16 deletions(-)
diff --git a/drivers/serial/mfd.c b/drivers/serial/mfd.c
index 5fc699e..d40010a 100644
--- a/drivers/serial/mfd.c
+++ b/drivers/serial/mfd.c
@@ -900,8 +900,7 @@ serial_hsu_set_termios(struct uart_port *port, struct ktermios *termios,
unsigned char cval, fcr = 0;
unsigned long flags;
unsigned int baud, quot;
- u32 mul = 0x3600;
- u32 ps = 0x10;
+ u32 ps, mul;

switch (termios->c_cflag & CSIZE) {
case CS5:
@@ -943,31 +942,24 @@ serial_hsu_set_termios(struct uart_port *port, struct ktermios *termios,
baud = uart_get_baud_rate(port, termios, old, 0, 4000000);

quot = 1;
+ ps = 0x10;
+ mul = 0x3600;
switch (baud) {
case 3500000:
mul = 0x3345;
ps = 0xC;
break;
- case 3000000:
- mul = 0x2EE0;
- break;
- case 2500000:
- mul = 0x2710;
- break;
- case 2000000:
- mul = 0x1F40;
- break;
case 1843200:
mul = 0x2400;
break;
+ case 3000000:
+ case 2500000:
+ case 2000000:
case 1500000:
- mul = 0x1770;
- break;
case 1000000:
- mul = 0xFA0;
- break;
case 500000:
- mul = 0x7D0;
+ /* mul/ps/quot = 0x9C4/0x10/0x1 will make a 500000 bps */
+ mul = baud / 500000 * 0x9C4;
break;
default:
/* Use uart_get_divisor to get quot for other baud rates */
--
1.7.1


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