spi_bfin: wait for tx to complete on some cs_chg paths
PBX 2 SPI devices need the nonstandard "cs change per word" mechanism.
This patch is one of three updating this driver to make the last data bits get
sent before advancing the transfer ... in this case, before the chipselect
gets deactivated.
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index 52beb5c..ce4692c 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -294,16 +294,14 @@
{
struct chip_data *chip = drv_data->cur_chip;
- /* poll for SPI completion before start */
- while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
- cpu_relax();
-
while (drv_data->tx < drv_data->tx_end) {
cs_active(drv_data, chip);
write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
while (read_STAT(drv_data) & BIT_STAT_TXS)
cpu_relax();
+ while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
+ cpu_relax();
cs_deactive(drv_data, chip);
@@ -342,31 +340,20 @@
{
struct chip_data *chip = drv_data->cur_chip;
- /* poll for SPI completion before start */
- while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
- cpu_relax();
-
- /* clear TDBR buffer before read(else it will be shifted out) */
- write_TDBR(drv_data, 0xFFFF);
-
- cs_active(drv_data, chip);
- dummy_read(drv_data);
-
- while (drv_data->rx < drv_data->rx_end - 1) {
- cs_deactive(drv_data, chip);
+ while (drv_data->rx < drv_data->rx_end) {
+ cs_active(drv_data, chip);
+ read_RDBR(drv_data); /* kick off */
while (!(read_STAT(drv_data) & BIT_STAT_RXS))
cpu_relax();
- cs_active(drv_data, chip);
- *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
+ while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
+ cpu_relax();
+
+ *(u8 *) (drv_data->rx) = read_SHAW(drv_data);
+ cs_deactive(drv_data, chip);
+
++drv_data->rx;
}
- cs_deactive(drv_data, chip);
-
- while (!(read_STAT(drv_data) & BIT_STAT_RXS))
- cpu_relax();
- *(u8 *) (drv_data->rx) = read_SHAW(drv_data);
- ++drv_data->rx;
}
static void u8_duplex(struct driver_data *drv_data)
@@ -392,15 +379,12 @@
{
struct chip_data *chip = drv_data->cur_chip;
- /* poll for SPI completion before start */
- while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
- cpu_relax();
-
while (drv_data->rx < drv_data->rx_end) {
cs_active(drv_data, chip);
write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
- while (read_STAT(drv_data) & BIT_STAT_TXS)
+
+ while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
cpu_relax();
while (!(read_STAT(drv_data) & BIT_STAT_RXS))
cpu_relax();