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spi_bfin: wait for tx to complete on full duplex paths 

Full duplex SPI operation should not read a dummy byte at the first transfer.
Bug and fix by Jean-Christian de Rivaz <jc@eclis.ch>:

http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3678

Signed-off-by: Jean-Christian de Rivaz <jc@eclis.ch>
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>
This commit is contained in:
Bryan Wu 2008-02-06 01:38:19 -08:00 committed by Linus Torvalds
parent e26aa015dd
commit 4fd432d9c7
1 changed files with 3 additions and 15 deletions
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18
drivers/spi/spi_bfin5xx.c
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@ -358,14 +358,10 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
static void u8_duplex(struct driver_data *drv_data)
{
/* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
cpu_relax();
/* in duplex mode, clk is triggered by writing of TDBR */
while (drv_data->rx < drv_data->rx_end) {
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();
@ -495,14 +491,10 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
static void u16_duplex(struct driver_data *drv_data)
{
/* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
cpu_relax();
/* in duplex mode, clk is triggered by writing of TDBR */
while (drv_data->tx < drv_data->tx_end) {
write_TDBR(drv_data, (*(u16 *) (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();
@ -516,15 +508,11 @@ static void u16_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->tx < drv_data->tx_end) {
cs_active(drv_data, chip);
write_TDBR(drv_data, (*(u16 *) (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();