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authorBryan Wu <bryan.wu@analog.com>2008-02-06 01:38:18 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-06 10:41:11 -0800
commite26aa015dd34d5768b80815836ad60e8495e9553 (patch)
tree18521ecaa37b2d51b97f3b4f256762dca1d445cb
parentaab0d83ee771b19082c3ee24576cf5508d319294 (diff)
downloadblackbird-op-linux-e26aa015dd34d5768b80815836ad60e8495e9553.tar.gz
blackbird-op-linux-e26aa015dd34d5768b80815836ad60e8495e9553.zip
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>
-rw-r--r--drivers/spi/spi_bfin5xx.c40
1 files changed, 12 insertions, 28 deletions
diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index 52beb5c924b7..ce4692cdb3b2 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -294,16 +294,14 @@ static void u8_cs_chg_writer(struct driver_data *drv_data)
{
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 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
{
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);
+ while (drv_data->rx < drv_data->rx_end) {
+ cs_active(drv_data, chip);
+ read_RDBR(drv_data); /* kick off */
- cs_active(drv_data, chip);
- dummy_read(drv_data);
+ while (!(read_STAT(drv_data) & BIT_STAT_RXS))
+ cpu_relax();
+ while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
+ cpu_relax();
- while (drv_data->rx < drv_data->rx_end - 1) {
+ *(u8 *) (drv_data->rx) = read_SHAW(drv_data);
cs_deactive(drv_data, chip);
- while (!(read_STAT(drv_data) & BIT_STAT_RXS))
- cpu_relax();
- cs_active(drv_data, chip);
- *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
++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 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data)
{
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();
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