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>
diff --git a/drivers/ata/pata_bf54x.c b/drivers/ata/pata_bf54x.c
index 81db405..088a41f 100644
--- a/drivers/ata/pata_bf54x.c
+++ b/drivers/ata/pata_bf54x.c
@@ -1489,6 +1489,8 @@
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 @@
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..
*/