Applied "spi: bcm2835aux: fix CPOL/CPHA setting" to the spi tree

[Mark Brown <broonie@xxxxxxxxxx>]

The patch

   spi: bcm2835aux: fix CPOL/CPHA setting

has been applied to the spi tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From e9dd4edcc98593bbcdffc0c4f37545b8fd0ad3ea Mon Sep 17 00:00:00 2001
From: Stephan Olbrich <stephanolbrich@xxxxxx>
Date: Sun, 14 Feb 2016 11:04:29 +0100
Subject: [PATCH] spi: bcm2835aux: fix CPOL/CPHA setting

The auxiliary spi supports only CPHA=0 modes as the first bit is
always output to the pin before the first clock cycle. In CPHA=1
modes the first clock edge outputs the second bit hence the slave
can never read the first bit.

Also the CPHA registers switch between clocking data in/out on
rising/falling edge hence depend on the CPOL setting.

Signed-off-by: Stephan Olbrich <stephanolbrich@xxxxxx>
Reviewed-by: Eric Anholt <eric@xxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
 drivers/spi/spi-bcm2835aux.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c
index a6e25c6..496f9ad 100644
--- a/drivers/spi/spi-bcm2835aux.c
+++ b/drivers/spi/spi-bcm2835aux.c
@@ -64,9 +64,9 @@
 #define BCM2835_AUX_SPI_CNTL0_VAR_WIDTH	0x00004000
 #define BCM2835_AUX_SPI_CNTL0_DOUTHOLD	0x00003000
 #define BCM2835_AUX_SPI_CNTL0_ENABLE	0x00000800
-#define BCM2835_AUX_SPI_CNTL0_CPHA_IN	0x00000400
+#define BCM2835_AUX_SPI_CNTL0_IN_RISING	0x00000400
 #define BCM2835_AUX_SPI_CNTL0_CLEARFIFO	0x00000200
-#define BCM2835_AUX_SPI_CNTL0_CPHA_OUT	0x00000100
+#define BCM2835_AUX_SPI_CNTL0_OUT_RISING	0x00000100
 #define BCM2835_AUX_SPI_CNTL0_CPOL	0x00000080
 #define BCM2835_AUX_SPI_CNTL0_MSBF_OUT	0x00000040
 #define BCM2835_AUX_SPI_CNTL0_SHIFTLEN	0x0000003F
@@ -92,9 +92,6 @@
 #define BCM2835_AUX_SPI_POLLING_LIMIT_US	30
 #define BCM2835_AUX_SPI_POLLING_JIFFIES		2
 
-#define BCM2835_AUX_SPI_MODE_BITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
-				  | SPI_NO_CS)
-
 struct bcm2835aux_spi {
 	void __iomem *regs;
 	struct clk *clk;
@@ -389,12 +386,12 @@ static int bcm2835aux_spi_prepare_message(struct spi_master *master,
 	bs->cntl[1] = BCM2835_AUX_SPI_CNTL1_MSBF_IN;
 
 	/* handle all the modes */
-	if (spi->mode & SPI_CPOL)
+	if (spi->mode & SPI_CPOL) {
 		bs->cntl[0] |= BCM2835_AUX_SPI_CNTL0_CPOL;
-	if (spi->mode & SPI_CPHA)
-		bs->cntl[0] |= BCM2835_AUX_SPI_CNTL0_CPHA_OUT |
-			       BCM2835_AUX_SPI_CNTL0_CPHA_IN;
-
+		bs->cntl[0] |= BCM2835_AUX_SPI_CNTL0_OUT_RISING;
+	} else {
+		bs->cntl[0] |= BCM2835_AUX_SPI_CNTL0_IN_RISING;
+	}
 	bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL1, bs->cntl[1]);
 	bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL0, bs->cntl[0]);
 
@@ -434,7 +431,7 @@ static int bcm2835aux_spi_probe(struct platform_device *pdev)
 	}
 
 	platform_set_drvdata(pdev, master);
-	master->mode_bits = BCM2835_AUX_SPI_MODE_BITS;
+	master->mode_bits = (SPI_CPOL | SPI_CS_HIGH | SPI_NO_CS);
 	master->bits_per_word_mask = SPI_BPW_MASK(8);
 	master->num_chipselect = -1;
 	master->transfer_one = bcm2835aux_spi_transfer_one;
-- 
2.7.0

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