Unverified Commit af060b3f authored by Simon Goldschmidt's avatar Simon Goldschmidt Committed by Mark Brown
Browse files

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: default avatarSimon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 48c29d0d

drivers/spi/spi-dw.c

+5 −10
Original line number Diff line number Diff line
@@ -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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