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Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/bfin_spi.c16
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));
}