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Commit 13b10301 authored by Matthias Seidel's avatar Matthias Seidel Committed by Mark Brown
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spi: dw: fix multiple slaves with different baudrates 



Add current master clock to dws struct and compare it against the
requestedtransfer speed. Update clock divider only if necessary.

Signed-off-by: default avatarMatthias Seidel <kernel@mseidel.net>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 29b4817d

drivers/spi/spi-dw.c

+7 −8
Original line number Diff line number Diff line
@@ -283,7 +283,6 @@ static int dw_spi_transfer_one(struct spi_master *master, 
	struct chip_data *chip = spi_get_ctldata(spi);

	u8 imask = 0;

	u16 txlevel = 0;

	u16 clk_div;

	u32 cr0;

	int ret;
@@ -298,13 +297,13 @@ static int dw_spi_transfer_one(struct spi_master *master, 
	spi_enable_chip(dws, 0);



	/* Handle per transfer options for bpw and speed */

	if (transfer->speed_hz != dws->current_freq) {

		if (transfer->speed_hz != chip->speed_hz) {

			/* clk_div doesn't support odd number */

		clk_div = (dws->max_freq / transfer->speed_hz + 1) & 0xfffe;



			chip->clk_div = (dws->max_freq / transfer->speed_hz + 1) & 0xfffe;

			chip->speed_hz = transfer->speed_hz;

		chip->clk_div = clk_div;



		}

		dws->current_freq = transfer->speed_hz;

		spi_set_clk(dws, chip->clk_div);

	}

	if (transfer->bits_per_word == 8) {

drivers/spi/spi-dw.h

+1 −0
Original line number Diff line number Diff line
@@ -123,6 +123,7 @@ struct dw_spi { 
	u8			n_bytes;	/* current is a 1/2 bytes op */

	u32			dma_width;

	irqreturn_t		(*transfer_handler)(struct dw_spi *dws);

	u32			current_freq;	/* frequency in hz */



	/* DMA info */

	int			dma_inited;