[patch 2.6.22-rc3] spi controller mode check update

[patch 2.6.22-rc3] spi controller mode check update

[David Brownell]

This lets bitbanging SPI controller drivers declare that they
support modes like SPI_CS_HIGH and SPI_3WIRE.

Signed-off-by: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>

---
This updates a patch in 2.6.22-rc3 called
  
	spi-controller-drivers-check-for-unsupported-modes.patch

 drivers/spi/spi_bitbang.c       |   12 +++---------
 include/linux/spi/spi_bitbang.h |    1 +
 2 files changed, 4 insertions(+), 9 deletions(-)

--- g26.orig/include/linux/spi/spi_bitbang.h	2007-06-01 16:25:23.000000000 -0700
+++ g26/include/linux/spi/spi_bitbang.h	2007-06-01 16:26:06.000000000 -0700
@@ -26,6 +26,7 @@ struct spi_bitbang {
 	struct list_head	queue;
 	u8			busy;
 	u8			use_dma;
+	u8			flags;		/* extra spi->mode support */
 
 	struct spi_master	*master;
 
--- g26.orig/drivers/spi/spi_bitbang.c	2007-06-01 16:25:23.000000000 -0700
+++ g26/drivers/spi/spi_bitbang.c	2007-06-01 16:26:06.000000000 -0700
@@ -187,16 +187,10 @@ int spi_bitbang_setup(struct spi_device 
 
 	bitbang = spi_master_get_devdata(spi->master);
 
-	/* REVISIT: some systems will want to support devices using lsb-first
-	 * bit encodings on the wire.  In pure software that would be trivial,
-	 * just bitbang_txrx_le_cphaX() routines shifting the other way, and
-	 * some hardware controllers also have this support.
-	 *
-	 * REVISIT: we should accept SPI_CS_HIGH in some cases; it's
-	 * easy to implement that with GPIOs, but we don't know if the
-	 * underlying chipselect() method support that...
+	/* Bitbangers can support SPI_CS_HIGH, SPI_3WIRE, and so on;
+	 * add those to master->flags, and provide the other support.
 	 */
-	if ((spi->mode & ~(SPI_CPOL|SPI_CPHA)) != 0)
+	if ((spi->mode & ~(SPI_CPOL|SPI_CPHA|bitbang->flags)) != 0)
 		return -EINVAL;
 
 	if (!cs) {

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