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* [patch 2.6.22-rc2-git] ads7846: SPI_CPHA mode bugfix
@ 2007-05-22 20:59 David Brownell
  0 siblings, 0 replies; only message in thread
From: David Brownell @ 2007-05-22 20:59 UTC (permalink / raw)
  To: Dmitry Torokhov, Andrew Morton
  Cc: Linux Kernel list, linux-input, Semih Hazar, Nicolas Ferre,
	Tony Lindgren, imre.deak

From: Semih Hazar <semih.hazar@indefia.com>

In commit [1] the SPI mode is set to 1, but it should be 0.  As stated
in the commit, ads784x samples the data on the rising edge.  SPI mode 1
samples on the falling edge [2] though.

The root cause of this is a bug in the omap_uwire code, which treats
CPHA=1 incorrectly; so these two bugs cancel each other out on one
of the main regression test platforms for this driver.

[1] kernel.org GIT 7937e86a70235e1584486654687dc9908a11e00a
[2] http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

---
 drivers/input/touchscreen/ads7846.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- g26.orig/drivers/input/touchscreen/ads7846.c	2007-05-20 21:08:30.000000000 -0700
+++ g26/drivers/input/touchscreen/ads7846.c	2007-05-20 21:08:54.000000000 -0700
@@ -847,7 +847,7 @@ static int __devinit ads7846_probe(struc
 	 * may not.  So we stick to very-portable 8 bit words, both RX and TX.
 	 */
 	spi->bits_per_word = 8;
-	spi->mode = SPI_MODE_1;
+	spi->mode = SPI_MODE_0;
 	err = spi_setup(spi);
 	if (err < 0)
 		return err;

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2007-05-22 20:59 [patch 2.6.22-rc2-git] ads7846: SPI_CPHA mode bugfix David Brownell

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