summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-dw.c
diff options
context:
space:
mode:
authorMatthias Seidel <kernel@mseidel.net>2016-09-04 02:04:49 +0200
committerMark Brown <broonie@kernel.org>2016-09-06 11:53:50 +0100
commit13b10301b858e355613bfc6dc297580bf34d3fb5 (patch)
treebe671ff360bb3c0f4c88982f6c64ed8a36193692 /drivers/spi/spi-dw.c
parent29b4817d4018df78086157ea3a55c1d9424a7cfc (diff)
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>
Diffstat (limited to 'drivers/spi/spi-dw.c')
-rw-r--r--drivers/spi/spi-dw.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index c09bb745693a..c85e4b327a4a 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -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) {