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authorMarcus Weseloh <mweseloh42@gmail.com>2016-01-05 21:46:20 +0100
committerMark Brown <broonie@kernel.org>2016-01-07 15:41:25 +0000
commit218e0b575ffe6de1c93249871b25bbf570fe1cb5 (patch)
tree11a31b1449cb713465b52bc2d565a2539ae6b315 /drivers/spi
parent8005c49d9aea74d382f474ce11afbbc7d7130bec (diff)
downloadlinux-218e0b575ffe6de1c93249871b25bbf570fe1cb5.tar.bz2
spi: sun4i: Prevent chip-select from being activated twice before a transfer
The SPI core calls set_cs before a transfer, but the SUN4I_CTL_CS_MANUAL flag is only set in transfer_one. This leads to the following pattern on the chip-select line (with runtime power-management on every transfer, without it only on the first one): activate, deactivate, activate, transfer, deactivate Moving the configuration of the SUN4I_CTL_CS_MANUAL flag from transfer_one to set_cs removes the double activation. Signed-off-by: Marcus Weseloh <mweseloh42@gmail.com> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-sun4i.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c
index fbb0a4d74e91..a6d936c68674 100644
--- a/drivers/spi/spi-sun4i.c
+++ b/drivers/spi/spi-sun4i.c
@@ -140,6 +140,9 @@ static void sun4i_spi_set_cs(struct spi_device *spi, bool enable)
reg &= ~SUN4I_CTL_CS_MASK;
reg |= SUN4I_CTL_CS(spi->chip_select);
+ /* We want to control the chip select manually */
+ reg |= SUN4I_CTL_CS_MANUAL;
+
if (enable)
reg |= SUN4I_CTL_CS_LEVEL;
else
@@ -222,9 +225,6 @@ static int sun4i_spi_transfer_one(struct spi_master *master,
else
reg |= SUN4I_CTL_DHB;
- /* We want to control the chip select manually */
- reg |= SUN4I_CTL_CS_MANUAL;
-
sun4i_spi_write(sspi, SUN4I_CTL_REG, reg);
/* Ensure that we have a parent clock fast enough */