diff options
| author | Bryan Wu <bryan.wu@analog.com> | 2007-12-04 23:45:20 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-12-05 09:21:20 -0800 |
| commit | 62310e51ac10c5e50998240e49a84d2e28377a48 (patch) | |
| tree | bdb678ea08edb8bbe83ac77bd4432e1d1721e44e /drivers/spi/spi_bfin5xx.c | |
| parent | c3061abb9e95920407288cba143dc1af0babf099 (diff) | |
| download | lwn-62310e51ac10c5e50998240e49a84d2e28377a48.tar.gz lwn-62310e51ac10c5e50998240e49a84d2e28377a48.zip | |
spi: spi_bfin: update handling of delay-after-deselect
Move cs_chg_udelay handling (specific to this driver) to cs_deactive(), fixing
a bug when some SPI LCD driver needs delay after cs_deactive.
Fix bug reported by Cameron Barfield <cbarfield@cyberdata.net>
https://blackfin.uclinux.org/gf/project/uclinux-dist/forum/?action=ForumBrowse&forum_id=39&_forum_action=ForumMessageBrowse&thread_id=23630&feedback=Message%20replied.
Cc: Cameron Barfield <cbarfield@cyberdata.net>
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>
Diffstat (limited to 'drivers/spi/spi_bfin5xx.c')
| -rw-r--r-- | drivers/spi/spi_bfin5xx.c | 24 |
1 files changed, 9 insertions, 15 deletions
diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c index 25b0efc5910e..4dc7e6749322 100644 --- a/drivers/spi/spi_bfin5xx.c +++ b/drivers/spi/spi_bfin5xx.c @@ -132,7 +132,7 @@ struct chip_data { u8 enable_dma; u8 bits_per_word; /* 8 or 16 */ u8 cs_change_per_word; - u8 cs_chg_udelay; + u16 cs_chg_udelay; /* Some devices require > 255usec delay */ void (*write) (struct driver_data *); void (*read) (struct driver_data *); void (*duplex) (struct driver_data *); @@ -211,6 +211,10 @@ static void cs_deactive(struct driver_data *drv_data, struct chip_data *chip) flag |= (chip->flag << 8); write_FLAG(drv_data, flag); + + /* Move delay here for consistency */ + if (chip->cs_chg_udelay) + udelay(chip->cs_chg_udelay); } #define MAX_SPI_SSEL 7 @@ -307,10 +311,9 @@ static void u8_cs_chg_writer(struct driver_data *drv_data) write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); while (read_STAT(drv_data) & BIT_STAT_TXS) continue; + cs_deactive(drv_data, chip); - if (chip->cs_chg_udelay) - udelay(chip->cs_chg_udelay); ++drv_data->tx; } } @@ -359,9 +362,6 @@ static void u8_cs_chg_reader(struct driver_data *drv_data) while (drv_data->rx < drv_data->rx_end - 1) { cs_deactive(drv_data, chip); - if (chip->cs_chg_udelay) - udelay(chip->cs_chg_udelay); - while (!(read_STAT(drv_data) & BIT_STAT_RXS)) continue; cs_active(drv_data, chip); @@ -412,10 +412,9 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data) while (!(read_STAT(drv_data) & BIT_STAT_RXS)) continue; *(u8 *) (drv_data->rx) = read_RDBR(drv_data); + cs_deactive(drv_data, chip); - if (chip->cs_chg_udelay) - udelay(chip->cs_chg_udelay); ++drv_data->rx; ++drv_data->tx; } @@ -452,10 +451,9 @@ static void u16_cs_chg_writer(struct driver_data *drv_data) write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); while ((read_STAT(drv_data) & BIT_STAT_TXS)) continue; + cs_deactive(drv_data, chip); - if (chip->cs_chg_udelay) - udelay(chip->cs_chg_udelay); drv_data->tx += 2; } } @@ -504,9 +502,6 @@ static void u16_cs_chg_reader(struct driver_data *drv_data) while (drv_data->rx < drv_data->rx_end - 2) { cs_deactive(drv_data, chip); - if (chip->cs_chg_udelay) - udelay(chip->cs_chg_udelay); - while (!(read_STAT(drv_data) & BIT_STAT_RXS)) continue; cs_active(drv_data, chip); @@ -557,10 +552,9 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data) while (!(read_STAT(drv_data) & BIT_STAT_RXS)) continue; *(u16 *) (drv_data->rx) = read_RDBR(drv_data); + cs_deactive(drv_data, chip); - if (chip->cs_chg_udelay) - udelay(chip->cs_chg_udelay); drv_data->rx += 2; drv_data->tx += 2; } |