Merge branch 'spi/merge' of git://git.secretlab.ca/git/linux-2.6

* 'spi/merge' of git://git.secretlab.ca/git/linux-2.6:
  devicetree-discuss is moderated for non-subscribers
  MAINTAINERS: Add entry for GPIO subsystem
  dt: add documentation of ARM dt boot interface
  dt: Remove obsolete description of powerpc boot interface
  dt: Move device tree documentation out of powerpc directory
  spi/spi_sh_msiof: fix wrong address calculation, which leads to an Oops

Documentation/arm/Booting

@@ -65,13 +65,19 @@ looks at the connected hardware is beyond the scope of this document.
 The boot loader must ultimately be able to provide a MACH_TYPE_xxx
 value to the kernel. (see linux/arch/arm/tools/mach-types).
 
-
-4. Setup the kernel tagged list
--------------------------------
+4. Setup boot data
+------------------
 
 Existing boot loaders:		OPTIONAL, HIGHLY RECOMMENDED
 New boot loaders:		MANDATORY
 
+The boot loader must provide either a tagged list or a dtb image for
+passing configuration data to the kernel.  The physical address of the
+boot data is passed to the kernel in register r2.
+
+4a. Setup the kernel tagged list
+--------------------------------
+
 The boot loader must create and initialise the kernel tagged list.
 A valid tagged list starts with ATAG_CORE and ends with ATAG_NONE.
 The ATAG_CORE tag may or may not be empty.  An empty ATAG_CORE tag
@@ -101,6 +107,24 @@ The tagged list must be placed in a region of memory where neither
 the kernel decompressor nor initrd 'bootp' program will overwrite
 it.  The recommended placement is in the first 16KiB of RAM.
 
+4b. Setup the device tree
+-------------------------
+
+The boot loader must load a device tree image (dtb) into system ram
+at a 64bit aligned address and initialize it with the boot data.  The
+dtb format is documented in Documentation/devicetree/booting-without-of.txt.
+The kernel will look for the dtb magic value of 0xd00dfeed at the dtb
+physical address to determine if a dtb has been passed instead of a
+tagged list.
+
+The boot loader must pass at a minimum the size and location of the
+system memory, and the root filesystem location.  The dtb must be
+placed in a region of memory where the kernel decompressor will not
+overwrite it.  The recommended placement is in the first 16KiB of RAM
+with the caveat that it may not be located at physical address 0 since
+the kernel interprets a value of 0 in r2 to mean neither a tagged list
+nor a dtb were passed.
+
 5. Calling the kernel image
 ---------------------------
 
@@ -125,7 +149,8 @@ In either case, the following conditions must be met:
 - CPU register settings
   r0 = 0,
   r1 = machine type number discovered in (3) above.
-  r2 = physical address of tagged list in system RAM.
+  r2 = physical address of tagged list in system RAM, or
+       physical address of device tree block (dtb) in system RAM
 
 - CPU mode
   All forms of interrupts must be disabled (IRQs and FIQs)

MAINTAINERS

@@ -4600,7 +4600,7 @@ F:	drivers/i2c/busses/i2c-ocores.c
 
 OPEN FIRMWARE AND FLATTENED DEVICE TREE
 M:	Grant Likely <[email protected]>
-L:	[email protected]
+L:	[email protected] (moderated for non-subscribers)
 W:	http://fdt.secretlab.ca
 T:	git git://git.secretlab.ca/git/linux-2.6.git
 S:	Maintained

drivers/spi/spi_sh_msiof.c

@@ -509,9 +509,11 @@ static int sh_msiof_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
 	bytes_done = 0;
 
 	while (bytes_done < t->len) {
+		void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
+		const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
 		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
-					   t->tx_buf + bytes_done,
-					   t->rx_buf + bytes_done,
+					   tx_buf,
+					   rx_buf,
 					   words, bits);
 		if (n < 0)
 			break;