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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>
This commit is contained in:
Marcus Weseloh 2016-01-05 21:46:20 +01:00 committed by Mark Brown
parent 8005c49d9a
commit 218e0b575f
1 changed files with 3 additions and 3 deletions
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6
drivers/spi/spi-sun4i.c
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@ -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 */