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spi: dw: support 4-16 bits per word

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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>
This commit is contained in:
Simon Goldschmidt 2018-09-04 21:49:44 +02:00 committed by Mark Brown
parent 48c29d0d27
commit af060b3f72
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GPG Key ID: 24D68B725D5487D0
1 changed files with 5 additions and 10 deletions
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15
drivers/spi/spi-dw.c
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@ -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;