Set proper ATA UDMA mode for bf548 according to system clock.

UDMA Mode - Frequency compatibility

UDMA5 - 100 MB/s   - SCLK  = 133 MHz
UDMA4 - 66 MB/s    - SCLK >=  80 MHz
UDMA3 - 44.4 MB/s  - SCLK >=  50 MHz
UDMA2 - 33 MB/s    - SCLK >=  40 MHz

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
sonic zhang 2007-11-27 12:47:39 +08:00 committed by Jeff Garzik
parent 92d499d991
commit f88c480dac

View File

@ -1489,6 +1489,8 @@ static int __devinit bfin_atapi_probe(struct platform_device *pdev)
int board_idx = 0;
struct resource *res;
struct ata_host *host;
unsigned int fsclk = get_sclk();
int udma_mode = 5;
const struct ata_port_info *ppi[] =
{ &bfin_port_info[board_idx], NULL };
@ -1507,6 +1509,11 @@ static int __devinit bfin_atapi_probe(struct platform_device *pdev)
if (res == NULL)
return -EINVAL;
while (bfin_port_info[board_idx].udma_mask>0 && udma_fsclk[udma_mode] > fsclk) {
udma_mode--;
bfin_port_info[board_idx].udma_mask >>= 1;
}
/*
* Now that that's out of the way, wire up the port..
*/