diff options
Diffstat (limited to 'drivers/spi/bfin_spi.c')
| -rw-r--r-- | drivers/spi/bfin_spi.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/spi/bfin_spi.c b/drivers/spi/bfin_spi.c index bc3394a..bc255cc 100644 --- a/drivers/spi/bfin_spi.c +++ b/drivers/spi/bfin_spi.c @@ -52,6 +52,7 @@ void spi_cs_activate(struct spi_slave *slave) (read_SPI_FLG(bss) & ~((!bss->flg << 8) << slave->cs)) | (1 << slave->cs)); + SSYNC(); debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss)); } @@ -59,7 +60,20 @@ __attribute__((weak)) void spi_cs_deactivate(struct spi_slave *slave) { struct bfin_spi_slave *bss = to_bfin_spi_slave(slave); - write_SPI_FLG(bss, read_SPI_FLG(bss) & ~(1 << slave->cs)); + u16 flg; + + /* make sure we force the cs to deassert rather than let the + * pin float back up. otherwise, exact timings may not be + * met some of the time leading to random behavior (ugh). + */ + flg = read_SPI_FLG(bss) | ((!bss->flg << 8) << slave->cs); + write_SPI_FLG(bss, flg); + SSYNC(); + debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss)); + + flg &= ~(1 << slave->cs); + write_SPI_FLG(bss, flg); + SSYNC(); debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss)); } |