diff options
| author |   Cory Maccarrone <darkstar6262@gmail.com> | 2010-05-30 00:12:23 +0000 |
|---|---|---|
| committer |   Grant Likely <grant.likely@secretlab.ca> | 2010-07-03 22:45:44 -0600 |
| commit | 5c2818cdfad1973ede3dcd2a8709620a192f8385 (patch) | |
| tree | c23de1403063aaff5e489636bee97ef7715514a8 /drivers/spi | |
| parent | spi/mmc_spi: mmc_spi adaptations for SPI bus locking API (diff) | |
| download | linux-dev-5c2818cdfad1973ede3dcd2a8709620a192f8385.tar.xz linux-dev-5c2818cdfad1973ede3dcd2a8709620a192f8385.zip | |
SPI100k: Fix 8-bit and RX-only transfers
This change fixes 8-bit transfers and RX-only transfers. The
SPI100k framework requires minimum 16-bit words to be written, so 8-bit
transfers must be shited by 8 bits and sent out as a 16-bit word.
Additionally, receive-only transfers were failing due to the
perceived need to fill the TX buffer with something. This is in
fact not needed.
Signed-off-by: Cory Maccarrone <darkstar6262@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/omap_spi_100k.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/drivers/spi/omap_spi_100k.c b/drivers/spi/omap_spi_100k.c index 24668b30a52d..9bd1c92ad96e 100644 --- a/drivers/spi/omap_spi_100k.c +++ b/drivers/spi/omap_spi_100k.c @@ -141,7 +141,12 @@ static void spi100k_write_data(struct spi_master *master, int len, int data) { struct omap1_spi100k *spi100k = spi_master_get_devdata(master); - /* write 16-bit word */ + /* write 16-bit word, shifting 8-bit data if necessary */ + if (len <= 8) { + data <<= 8; + len = 16; + } + spi100k_enable_clock(master); writew( data , spi100k->base + SPI_TX_MSB); @@ -162,6 +167,10 @@ static int spi100k_read_data(struct spi_master *master, int len) int dataH,dataL; struct omap1_spi100k *spi100k = spi_master_get_devdata(master); + /* Always do at least 16 bits */ + if (len <= 8) + len = 16; + spi100k_enable_clock(master); writew(SPI_CTRL_SEN(0) | SPI_CTRL_WORD_SIZE(len) | @@ -214,10 +223,6 @@ omap1_spi100k_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) c = count; word_len = cs->word_len; - /* RX_ONLY mode needs dummy data in TX reg */ - if (xfer->tx_buf == NULL) - spi100k_write_data(spi->master,word_len, 0); - if (word_len <= 8) { u8 *rx; const u8 *tx; @@ -227,9 +232,9 @@ omap1_spi100k_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) do { c-=1; if (xfer->tx_buf != NULL) - spi100k_write_data(spi->master,word_len, *tx); + spi100k_write_data(spi->master, word_len, *tx++); if (xfer->rx_buf != NULL) - *rx = spi100k_read_data(spi->master,word_len); + *rx++ = spi100k_read_data(spi->master, word_len); } while(c); } else if (word_len <= 16) { u16 *rx; @@ -380,10 +385,6 @@ static void omap1_spi100k_work(struct work_struct *work) if (t->len) { unsigned count; - /* RX_ONLY mode needs dummy data in TX reg */ - if (t->tx_buf == NULL) - spi100k_write_data(spi->master, 8, 0); - count = omap1_spi100k_txrx_pio(spi, t); m->actual_length += count; |