releases/2.6.36.2/serial-mfd-adjust-the-baud-rate-setting.patch

   1 From a5880a9e5bb40fbae55de60051d69a29091053c3 Mon Sep 17 00:00:00 2001
   2 From: Feng Tang <feng.tang@intel.com>
   3 Date: Fri, 19 Nov 2010 11:01:48 +0800
   4 Subject: serial: mfd: adjust the baud rate setting
   5
   6 From: Feng Tang <feng.tang@intel.com>
   7
   8 commit a5880a9e5bb40fbae55de60051d69a29091053c3 upstream.
   9
  10 Previous baud rate setting code only has been tested with 3.5M/9600/
  11 115200/230400/460800 bps, and recently we got a 3M bps device to test,
  12 which needs to modify current MUL register setting, and with this
  13 patch 2.5M/2M/1.5M/1M/0.5M should also work as they just use a MUL
  14 value scale down from 3M's.
  15
  16 Also got some reference register setting from silicon guys for
  17 different baud rates, which tries to keep the pre-scalar register value
  18 to 16.
  19
  20 Signed-off-by: Feng Tang <feng.tang@intel.com>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  22
  23 ---
  24  drivers/serial/mfd.c |   18 ++++++++----------
  25  1 file changed, 8 insertions(+), 10 deletions(-)
  26
  27 --- a/drivers/serial/mfd.c
  28 +++ b/drivers/serial/mfd.c
  29 @@ -892,8 +892,7 @@ serial_hsu_set_termios(struct uart_port
  30         unsigned char cval, fcr = 0;
  31         unsigned long flags;
  32         unsigned int baud, quot;
  33 -       u32 mul = 0x3600;
  34 -       u32 ps = 0x10;
  35 +       u32 ps, mul;
  36
  37         switch (termios->c_cflag & CSIZE) {
  38         case CS5:
  39 @@ -937,20 +936,19 @@ serial_hsu_set_termios(struct uart_port
  40                 ps = 0xC;
  41                 quot = 1;
  42                 break;
  43 -       case 2500000:
  44 -               mul = 0x2710;
  45 -               ps = 0x10;
  46 -               quot = 1;
  47 -               break;
  48         case 18432000:
  49                 mul = 0x2400;
  50                 ps = 0x10;
  51                 quot = 1;
  52                 break;
  53 +       case 3000000:
  54 +       case 2500000:
  55 +       case 2000000:
  56         case 1500000:
  57 -               mul = 0x1D4C;
  58 -               ps = 0xc;
  59 -               quot = 1;
  60 +       case 1000000:
  61 +       case 500000:
  62 +               /* mul/ps/quot = 0x9C4/0x10/0x1 will make a 500000 bps */
  63 +               mul = baud / 500000 * 0x9C4;
  64                 break;
  65         default:
  66                 ;