diff options
| -rw-r--r-- | drivers/spi/dw_spi.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index f713af8309e..d948ef4f391 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -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) |