GitHub-Mirror/u-boot
2
0
Fork 0
mirror of https://github.com/Fishwaldo/u-boot.git synced 2025-03-21 22:51:37 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Blackfin: make baud calculation more accurate

Browse source 
We should use the algorithm in the Linux kernel so that the UART divisor
calculation is more accurate.  It also fixes problems on some picky UARTs
that have sampling anomalies.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This commit is contained in:
Mike Frysinger 2008-04-20 03:11:53 -04:00
parent 0ba1da116e
commit 25cd33d82e
1 changed files with 4 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
cpu/blackfin/serial.h
View file

@ -175,11 +175,11 @@ static inline uint32_t serial_early_get_baud(void)
__attribute__((always_inline)) __attribute__((always_inline))
static inline void serial_early_set_baud(uint32_t baud) static inline void serial_early_set_baud(uint32_t baud)
{ {
/* Translate from baud into divisor in terms of SCLK. /* Translate from baud into divisor in terms of SCLK. The
* The +1 is to make sure we over sample just a little * weird multiplication is to make sure we over sample just
* rather than under sample the incoming signals. * a little rather than under sample the incoming signals.
*/ */
uint16_t divisor = (get_sclk() / (baud * 16)) + 1; uint16_t divisor = (get_sclk() + (baud * 8)) / (baud * 16) - ANOMALY_05000230;
/* Set DLAB in LCR to Access DLL and DLH */ /* Set DLAB in LCR to Access DLL and DLH */
ACCESS_LATCH(); ACCESS_LATCH();