forked from luck/tmp_suning_uos_patched
spi/dw_spi: add a FIFO depth detection
FIFO depth is configurable for each implementation of DW core, so add a depth detection for those interface drivers who don't set the fifo_len explicitly Signed-off-by: Feng Tang <feng.tang@intel.com> Acked-by: Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
parent
99147b5c41
commit
c587b6fa05
@ -831,6 +831,22 @@ static void spi_hw_init(struct dw_spi *dws)
|
||||
spi_mask_intr(dws, 0xff);
|
||||
spi_enable_chip(dws, 1);
|
||||
flush(dws);
|
||||
|
||||
/*
|
||||
* Try to detect the FIFO depth if not set by interface driver,
|
||||
* the depth could be from 2 to 256 from HW spec
|
||||
*/
|
||||
if (!dws->fifo_len) {
|
||||
u32 fifo;
|
||||
for (fifo = 2; fifo <= 257; fifo++) {
|
||||
dw_writew(dws, txfltr, fifo);
|
||||
if (fifo != dw_readw(dws, txfltr))
|
||||
break;
|
||||
}
|
||||
|
||||
dws->fifo_len = (fifo == 257) ? 0 : fifo;
|
||||
dw_writew(dws, txfltr, 0);
|
||||
}
|
||||
}
|
||||
|
||||
int __devinit dw_spi_add_host(struct dw_spi *dws)
|
||||
|
Loading…
Reference in New Issue
Block a user