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authorSimon Goldschmidt <simon.k.r.goldschmidt@gmail.com>2018-09-04 21:49:44 +0200
committerMark Brown <broonie@kernel.org>2018-09-06 12:09:37 +0100
commitaf060b3f72b801962033f75a2fda25fff992796d (patch)
treed4c37f8b64d86ef924a7422a0cf278b33c8b3f47
parent48c29d0d27fbbb4c78d3c14c50067d7e8919ed95 (diff)
downloadblackbird-op-linux-af060b3f72b801962033f75a2fda25fff992796d.tar.gz
blackbird-op-linux-af060b3f72b801962033f75a2fda25fff992796d.zip
spi: dw: support 4-16 bits per word
The spi-dw driver currently only supports 8 or 16 bits per word. Since the hardware supports 4-16 bits per word, adapt the driver to also support this. Tested on socfpga cyclone5 with a 9-bit SPI display. Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
-rw-r--r--drivers/spi/spi-dw.c15
1 files changed, 5 insertions, 10 deletions
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index 1736612ee86b..3e205ab60cd4 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -308,15 +308,10 @@ static int dw_spi_transfer_one(struct spi_controller *master,
dws->current_freq = transfer->speed_hz;
spi_set_clk(dws, chip->clk_div);
}
- if (transfer->bits_per_word == 8) {
- dws->n_bytes = 1;
- dws->dma_width = 1;
- } else if (transfer->bits_per_word == 16) {
- dws->n_bytes = 2;
- dws->dma_width = 2;
- } else {
- return -EINVAL;
- }
+
+ dws->n_bytes = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
+ dws->dma_width = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
+
/* Default SPI mode is SCPOL = 0, SCPH = 0 */
cr0 = (transfer->bits_per_word - 1)
| (chip->type << SPI_FRF_OFFSET)
@@ -496,7 +491,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
}
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
- master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
master->bus_num = dws->bus_num;
master->num_chipselect = dws->num_cs;
master->setup = dw_spi_setup;
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