[kernel] backport SPI master with no RXTX support (from 2.6.36)

Signed-off-by: Miguel Gaio <miguel.gaio@efixo.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@23498 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 237 insertions, 0 deletions

diff --git a/target/linux/brcm63xx/patches-2.6.35/120-spi-bitbang-norxtx-support.patch b/target/linux/brcm63xx/patches-2.6.35/120-spi-bitbang-norxtx-support.patch
new file mode 100644
index 0000000000..762bc66fd4
--- /dev/null
+++ b/target/linux/brcm63xx/patches-2.6.35/120-spi-bitbang-norxtx-support.patch
@@ -0,0 +1,237 @@
+From 04bb2a031cf95b34b7432dd47b318a932a895b4c Mon Sep 17 00:00:00 2001
+From: Marek Szyprowski <m.szyprowski@samsung.com>
+Date: Wed, 30 Jun 2010 14:27:32 -0600
+Subject: [PATCH] spi/bitbang: add support for SPI_MASTER_NO_{TX, RX} modes
+
+This patch adds a new flags argument to bitbang_txrx_be_cpha0 and
+bitbang_txrx_be_cpha1 transfer functions. This enables support for
+SPI_MASTER_NO_{TX,RX} transfer modes. The change should have no impact
+on speed of the existing drivers. bitbank_txrx_* functions are usually
+inlined into the drivers. When the argument is equal to constant zero,
+the optimizer would be able to eliminate the dead code (flags checks)
+easily. Tested on ARM and GCC 4.4.x and in all cases the checks were
+eliminated in the inlined function.
+
+Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
+Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
+Acked-by: David Brownell <dbrownell@users.sourceforge.net>
+Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
+---
+ drivers/spi/spi_bitbang_txrx.h |   16 ++++++++++------
+ drivers/spi/spi_butterfly.c    |    2 +-
+ drivers/spi/spi_gpio.c         |    8 ++++----
+ drivers/spi/spi_lm70llp.c      |    2 +-
+ drivers/spi/spi_s3c24xx_gpio.c |    8 ++++----
+ drivers/spi/spi_sh_sci.c       |    8 ++++----
+ 6 files changed, 24 insertions(+), 20 deletions(-)
+
+--- a/drivers/spi/spi_bitbang_txrx.h
++++ b/drivers/spi/spi_bitbang_txrx.h
+@@ -44,7 +44,7 @@
+ 
+ static inline u32
+ bitbang_txrx_be_cpha0(struct spi_device *spi,
+-		unsigned nsecs, unsigned cpol,
++		unsigned nsecs, unsigned cpol, unsigned flags,
+ 		u32 word, u8 bits)
+ {
+ 	/* if (cpol == 0) this is SPI_MODE_0; else this is SPI_MODE_2 */
+@@ -53,7 +53,8 @@ bitbang_txrx_be_cpha0(struct spi_device
+ 	for (word <<= (32 - bits); likely(bits); bits--) {
+ 
+ 		/* setup MSB (to slave) on trailing edge */
+-		setmosi(spi, word & (1 << 31));
++		if ((flags & SPI_MASTER_NO_TX) == 0)
++			setmosi(spi, word & (1 << 31));
+ 		spidelay(nsecs);	/* T(setup) */
+ 
+ 		setsck(spi, !cpol);
+@@ -61,7 +62,8 @@ bitbang_txrx_be_cpha0(struct spi_device
+ 
+ 		/* sample MSB (from slave) on leading edge */
+ 		word <<= 1;
+-		word |= getmiso(spi);
++		if ((flags & SPI_MASTER_NO_RX) == 0)
++			word |= getmiso(spi);
+ 		setsck(spi, cpol);
+ 	}
+ 	return word;
+@@ -69,7 +71,7 @@ bitbang_txrx_be_cpha0(struct spi_device
+ 
+ static inline u32
+ bitbang_txrx_be_cpha1(struct spi_device *spi,
+-		unsigned nsecs, unsigned cpol,
++		unsigned nsecs, unsigned cpol, unsigned flags,
+ 		u32 word, u8 bits)
+ {
+ 	/* if (cpol == 0) this is SPI_MODE_1; else this is SPI_MODE_3 */
+@@ -79,7 +81,8 @@ bitbang_txrx_be_cpha1(struct spi_device
+ 
+ 		/* setup MSB (to slave) on leading edge */
+ 		setsck(spi, !cpol);
+-		setmosi(spi, word & (1 << 31));
++		if ((flags & SPI_MASTER_NO_TX) == 0)
++			setmosi(spi, word & (1 << 31));
+ 		spidelay(nsecs); /* T(setup) */
+ 
+ 		setsck(spi, cpol);
+@@ -87,7 +90,8 @@ bitbang_txrx_be_cpha1(struct spi_device
+ 
+ 		/* sample MSB (from slave) on trailing edge */
+ 		word <<= 1;
+-		word |= getmiso(spi);
++		if ((flags & SPI_MASTER_NO_RX) == 0)
++			word |= getmiso(spi);
+ 	}
+ 	return word;
+ }
+--- a/drivers/spi/spi_butterfly.c
++++ b/drivers/spi/spi_butterfly.c
+@@ -156,7 +156,7 @@ butterfly_txrx_word_mode0(struct spi_dev
+ 		unsigned nsecs,
+ 		u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
++	return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
+ }
+ 
+ /*----------------------------------------------------------------------*/
+--- a/drivers/spi/spi_gpio.c
++++ b/drivers/spi/spi_gpio.c
+@@ -157,25 +157,25 @@ static inline void spidelay(unsigned nse
+ static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi,
+ 		unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
++	return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
+ }
+ 
+ static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi,
+ 		unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
++	return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits);
+ }
+ 
+ static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi,
+ 		unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
++	return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits);
+ }
+ 
+ static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi,
+ 		unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
++	return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits);
+ }
+ 
+ /*----------------------------------------------------------------------*/
+--- a/drivers/spi/spi_lm70llp.c
++++ b/drivers/spi/spi_lm70llp.c
+@@ -191,7 +191,7 @@ static void lm70_chipselect(struct spi_d
+  */
+ static u32 lm70_txrx(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
++	return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
+ }
+ 
+ static void spi_lm70llp_attach(struct parport *p)
+--- a/drivers/spi/spi_s3c24xx_gpio.c
++++ b/drivers/spi/spi_s3c24xx_gpio.c
+@@ -64,25 +64,25 @@ static inline u32 getmiso(struct spi_dev
+ static u32 s3c2410_spigpio_txrx_mode0(struct spi_device *spi,
+ 				      unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
++	return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
+ }
+ 
+ static u32 s3c2410_spigpio_txrx_mode1(struct spi_device *spi,
+ 				      unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
++	return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits);
+ }
+ 
+ static u32 s3c2410_spigpio_txrx_mode2(struct spi_device *spi,
+ 				      unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
++	return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits);
+ }
+ 
+ static u32 s3c2410_spigpio_txrx_mode3(struct spi_device *spi,
+ 				      unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
++	return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits);
+ }
+ 
+ 
+--- a/drivers/spi/spi_sh_sci.c
++++ b/drivers/spi/spi_sh_sci.c
+@@ -83,25 +83,25 @@ static inline u32 getmiso(struct spi_dev
+ static u32 sh_sci_spi_txrx_mode0(struct spi_device *spi,
+ 				      unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
++	return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
+ }
+ 
+ static u32 sh_sci_spi_txrx_mode1(struct spi_device *spi,
+ 				      unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
++	return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits);
+ }
+ 
+ static u32 sh_sci_spi_txrx_mode2(struct spi_device *spi,
+ 				      unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
++	return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits);
+ }
+ 
+ static u32 sh_sci_spi_txrx_mode3(struct spi_device *spi,
+ 				      unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
++	return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits);
+ }
+ 
+ static void sh_sci_spi_chipselect(struct spi_device *dev, int value)
+--- a/drivers/spi/spi_gpio_old.c
++++ b/drivers/spi/spi_gpio_old.c
+@@ -80,25 +80,25 @@ static inline void do_spidelay(struct sp
+ static u32 spi_gpio_txrx_mode0(struct spi_device *spi,
+ 			       unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
++	return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
+ }
+ 
+ static u32 spi_gpio_txrx_mode1(struct spi_device *spi,
+ 			       unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
++	return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits);
+ }
+ 
+ static u32 spi_gpio_txrx_mode2(struct spi_device *spi,
+ 			       unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
++	return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits);
+ }
+ 
+ static u32 spi_gpio_txrx_mode3(struct spi_device *spi,
+ 			       unsigned nsecs, u32 word, u8 bits)
+ {
+-	return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
++	return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits);
+ }
+ 
+ static void spi_gpio_chipselect(struct spi_device *dev, int on)