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From dd7aa8d4b53b3484ba31ba56f3ff1be7deb38530 Mon Sep 17 00:00:00 2001
From: Maxime Chevallier <maxime.chevallier@smile.fr>
Date: Tue, 10 Oct 2017 10:43:18 +0200
Subject: spi: a3700: Change SPI mode before asserting chip-select
The spi device mode should be configured in the controller before the
chip-select is asserted, so that a clock polarity configuration change
is not interpreted as a clock tick by the device.
This patch moves the mode setting to the 'prepare_message' function
instead of the 'transfer_one' function.
By doing so, this patch also removes redundant code in
a3700_spi_clock_set.
This was tested on EspressoBin board, with spidev.
Signed-off-by: Maxime Chevallier <maxime.chevallier@smile.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
drivers/spi/spi-armada-3700.c | 17 ++++-------------
1 file changed, 4 insertions(+), 13 deletions(-)
--- a/drivers/spi/spi-armada-3700.c
+++ b/drivers/spi/spi-armada-3700.c
@@ -214,7 +214,7 @@ static void a3700_spi_mode_set(struct a3
}
static void a3700_spi_clock_set(struct a3700_spi *a3700_spi,
- unsigned int speed_hz, u16 mode)
+ unsigned int speed_hz)
{
u32 val;
u32 prescale;
@@ -239,17 +239,6 @@ static void a3700_spi_clock_set(struct a
val |= A3700_SPI_CLK_CAPT_EDGE;
spireg_write(a3700_spi, A3700_SPI_IF_TIME_REG, val);
}
-
- val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
- val &= ~(A3700_SPI_CLK_POL | A3700_SPI_CLK_PHA);
-
- if (mode & SPI_CPOL)
- val |= A3700_SPI_CLK_POL;
-
- if (mode & SPI_CPHA)
- val |= A3700_SPI_CLK_PHA;
-
- spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
}
static void a3700_spi_bytelen_set(struct a3700_spi *a3700_spi, unsigned int len)
@@ -431,7 +420,7 @@ static void a3700_spi_transfer_setup(str
a3700_spi = spi_master_get_devdata(spi->master);
- a3700_spi_clock_set(a3700_spi, xfer->speed_hz, spi->mode);
+ a3700_spi_clock_set(a3700_spi, xfer->speed_hz);
byte_len = xfer->bits_per_word >> 3;
@@ -592,6 +581,8 @@ static int a3700_spi_prepare_message(str
a3700_spi_bytelen_set(a3700_spi, 4);
+ a3700_spi_mode_set(a3700_spi, spi->mode);
+
return 0;
}
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