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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: Matthias Seidel <kernel@mseidel.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
hifive-unleashed-5.1
Matthias Seidel 2016-09-04 02:04:49 +02:00 committed by Mark Brown
parent 29b4817d40
commit 13b10301b8
2 changed files with 8 additions and 8 deletions
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15
drivers/spi/spi-dw.c
View File

@ -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 != chip->speed_hz) {
/* clk_div doesn't support odd number */
clk_div = (dws->max_freq / transfer->speed_hz + 1) & 0xfffe;
chip->speed_hz = transfer->speed_hz;
chip->clk_div = clk_div;
if (transfer->speed_hz != dws->current_freq) {
if (transfer->speed_hz != chip->speed_hz) {
/* clk_div doesn't support odd number */
chip->clk_div = (dws->max_freq / transfer->speed_hz + 1) & 0xfffe;
chip->speed_hz = transfer->speed_hz;
}
dws->current_freq = transfer->speed_hz;
spi_set_clk(dws, chip->clk_div);
}
if (transfer->bits_per_word == 8) {

1
drivers/spi/spi-dw.h
View File

@ -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;