Merge tag 'for-linus-20140610' of git://git.infradead.org/linux-mtd

Pull MTD updates from Brian Norris:
 - refactor m25p80.c driver for use as a general SPI NOR framework for
   other drivers which may speak to SPI NOR flash without providing full
   SPI support (i.e., not part of drivers/spi/)
 - new Freescale QuadSPI driver (utilizing new SPI NOR framework)
 - updates for the STMicro "FSM" SPI NOR driver
 - fix sync/flush behavior on mtd_blkdevs
 - fixup subpage write support on a few NAND drivers
 - correct the MTD OOB test for odd-sized OOB areas
 - add BCH-16 support for OMAP NAND
 - fix warnings and trivial refactoring
 - utilize new ECC DT bindings in pxa3xx NAND driver
 - new LPDDR NVM driver
 - address a few assorted bugs caught by Coverity
 - add new imx6sx support for GPMI NAND
 - use a bounce buffer for NAND when non-DMA-able buffers are used

* tag 'for-linus-20140610' of git://git.infradead.org/linux-mtd: (77 commits)
  mtd: gpmi: add gpmi support for imx6sx
  mtd: maps: remove check for CONFIG_MTD_SUPERH_RESERVE
  mtd: bf5xx_nand: use the managed version of kzalloc
  mtd: pxa3xx_nand: make the driver work on big-endian systems
  mtd: nand: omap: fix omap_calculate_ecc_bch() for-loop error
  mtd: nand: r852: correct write_buf loop bounds
  mtd: nand_bbt: handle error case for nand_create_badblock_pattern()
  mtd: nand_bbt: remove unused variable
  mtd: maps: sc520cdp: fix warnings
  mtd: slram: fix unused variable warning
  mtd: pfow: remove unused variable
  mtd: lpddr: fix Kconfig dependency, for I/O accessors
  mtd: nand: pxa3xx: Add supported ECC strength and step size to the DT binding
  mtd: nand: pxa3xx: Use ECC strength and step size devicetree binding
  mtd: nand: pxa3xx: Clean pxa_ecc_init() error handling
  mtd: nand: Warn the user if the selected ECC strength is too weak
  mtd: nand: omap: Documentation: How to select correct ECC scheme for your device ?
  mtd: nand: omap: add support for BCH16_ECC - NAND driver updates
  mtd: nand: omap: add support for BCH16_ECC - ELM driver updates
  mtd: nand: omap: add support for BCH16_ECC - GPMC driver updates
  ...

5 files changed, 152 insertions, 2 deletions

diff --git a/Documentation/devicetree/bindings/mtd/fsl-quadspi.txt b/Documentation/devicetree/bindings/mtd/fsl-quadspi.txt
new file mode 100644
index 00000000000..823d1341219
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/fsl-quadspi.txt
@@ -0,0 +1,35 @@
+* Freescale Quad Serial Peripheral Interface(QuadSPI)
+
+Required properties:
+  - compatible : Should be "fsl,vf610-qspi"
+  - reg : the first contains the register location and length,
+          the second contains the memory mapping address and length
+  - reg-names: Should contain the reg names "QuadSPI" and "QuadSPI-memory"
+  - interrupts : Should contain the interrupt for the device
+  - clocks : The clocks needed by the QuadSPI controller
+  - clock-names : the name of the clocks
+
+Optional properties:
+  - fsl,qspi-has-second-chip: The controller has two buses, bus A and bus B.
+                              Each bus can be connected with two NOR flashes.
+			      Most of the time, each bus only has one NOR flash
+			      connected, this is the default case.
+			      But if there are two NOR flashes connected to the
+			      bus, you should enable this property.
+			      (Please check the board's schematic.)
+
+Example:
+
+qspi0: quadspi@40044000 {
+	compatible = "fsl,vf610-qspi";
+	reg = <0x40044000 0x1000>, <0x20000000 0x10000000>;
+	reg-names = "QuadSPI", "QuadSPI-memory";
+	interrupts = <0 24 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&clks VF610_CLK_QSPI0_EN>,
+		<&clks VF610_CLK_QSPI0>;
+	clock-names = "qspi_en", "qspi";
+
+	flash0: s25fl128s@0 {
+		....
+	};
+};
diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
index eb05255b678..65f4f7c4313 100644
--- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
@@ -28,6 +28,8 @@ Optional properties:
 		"ham1"		1-bit Hamming ecc code
 		"bch4"		4-bit BCH ecc code
 		"bch8"		8-bit BCH ecc code
+		"bch16"		16-bit BCH ECC code
+		Refer below "How to select correct ECC scheme for your device ?"
 
  - ti,nand-xfer-type:		A string setting the data transfer type. One of:
 
@@ -90,3 +92,46 @@ Example for an AM33xx board:
 		};
 	};
 
+How to select correct ECC scheme for your device ?
+--------------------------------------------------
+Higher ECC scheme usually means better protection against bit-flips and
+increased system lifetime. However, selection of ECC scheme is dependent
+on various other factors also like;
+
+(1) support of built in hardware engines.
+	Some legacy OMAP SoC do not have ELM harware engine, so those SoC cannot
+	support ecc-schemes with hardware error-correction (BCHx_HW). However
+	such SoC can use ecc-schemes with software library for error-correction
+	(BCHx_HW_DETECTION_SW). The error correction capability with software
+	library remains equivalent to their hardware counter-part, but there is
+	slight CPU penalty when too many bit-flips are detected during reads.
+
+(2) Device parameters like OOBSIZE.
+	Other factor which governs the selection of ecc-scheme is oob-size.
+	Higher ECC schemes require more OOB/Spare area to store ECC syndrome,
+	so the device should have enough free bytes available its OOB/Spare
+	area to accomodate ECC for entire page. In general following expression
+	helps in determining if given device can accomodate ECC syndrome:
+	"2 + (PAGESIZE / 512) * ECC_BYTES" >= OOBSIZE"
+	where
+		OOBSIZE		number of bytes in OOB/spare area
+		PAGESIZE	number of bytes in main-area of device page
+		ECC_BYTES	number of ECC bytes generated to protect
+		                512 bytes of data, which is:
+				'3' for HAM1_xx ecc schemes
+				'7' for BCH4_xx ecc schemes
+				'14' for BCH8_xx ecc schemes
+				'26' for BCH16_xx ecc schemes
+
+	Example(a): For a device with PAGESIZE = 2048 and OOBSIZE = 64 and
+		trying to use BCH16 (ECC_BYTES=26) ecc-scheme.
+		Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B
+		which is greater than capacity of NAND device (OOBSIZE=64)
+		Hence, BCH16 cannot be supported on given device. But it can
+		probably use lower ecc-schemes like BCH8.
+
+	Example(b): For a device with PAGESIZE = 2048 and OOBSIZE = 128 and
+		trying to use BCH16 (ECC_BYTES=26) ecc-scheme.
+		Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B
+		which can be accomodate in the OOB/Spare area of this device
+		(OOBSIZE=128). So this device can use BCH16 ecc-scheme.
diff --git a/Documentation/devicetree/bindings/mtd/m25p80.txt b/Documentation/devicetree/bindings/mtd/m25p80.txt
index 6d3d5760947..4611aa83531 100644
--- a/Documentation/devicetree/bindings/mtd/m25p80.txt
+++ b/Documentation/devicetree/bindings/mtd/m25p80.txt
@@ -5,8 +5,8 @@ Required properties:
   representing partitions.
 - compatible : Should be the manufacturer and the name of the chip. Bear in mind
                the DT binding is not Linux-only, but in case of Linux, see the
-               "m25p_ids" table in drivers/mtd/devices/m25p80.c for the list of
-               supported chips.
+               "spi_nor_ids" table in drivers/mtd/spi-nor/spi-nor.c for the list
+               of supported chips.
 - reg : Chip-Select number
 - spi-max-frequency : Maximum frequency of the SPI bus the chip can operate at
 
diff --git a/Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt b/Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt
index 86e0a5601ff..de8b517a552 100644
--- a/Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt
@@ -17,6 +17,14 @@ Optional properties:
  - num-cs:			Number of chipselect lines to usw
  - nand-on-flash-bbt: 		boolean to enable on flash bbt option if
 				not present false
+ - nand-ecc-strength:           number of bits to correct per ECC step
+ - nand-ecc-step-size:          number of data bytes covered by a single ECC step
+
+The following ECC strength and step size are currently supported:
+
+ - nand-ecc-strength = <1>, nand-ecc-step-size = <512>
+ - nand-ecc-strength = <4>, nand-ecc-step-size = <512>
+ - nand-ecc-strength = <8>, nand-ecc-step-size = <512>
 
 Example:
 
diff --git a/Documentation/mtd/spi-nor.txt b/Documentation/mtd/spi-nor.txt
new file mode 100644
index 00000000000..548d6306ebc
--- /dev/null
+++ b/Documentation/mtd/spi-nor.txt
@@ -0,0 +1,62 @@
+                          SPI NOR framework
+               ============================================
+
+Part I - Why do we need this framework?
+---------------------------------------
+
+SPI bus controllers (drivers/spi/) only deal with streams of bytes; the bus
+controller operates agnostic of the specific device attached. However, some
+controllers (such as Freescale's QuadSPI controller) cannot easily handle
+arbitrary streams of bytes, but rather are designed specifically for SPI NOR.
+
+In particular, Freescale's QuadSPI controller must know the NOR commands to
+find the right LUT sequence. Unfortunately, the SPI subsystem has no notion of
+opcodes, addresses, or data payloads; a SPI controller simply knows to send or
+receive bytes (Tx and Rx). Therefore, we must define a new layering scheme under
+which the controller driver is aware of the opcodes, addressing, and other
+details of the SPI NOR protocol.
+
+Part II - How does the framework work?
+--------------------------------------
+
+This framework just adds a new layer between the MTD and the SPI bus driver.
+With this new layer, the SPI NOR controller driver does not depend on the
+m25p80 code anymore.
+
+   Before this framework, the layer is like:
+
+                   MTD
+         ------------------------
+                  m25p80
+         ------------------------
+	       SPI bus driver
+         ------------------------
+	        SPI NOR chip
+
+   After this framework, the layer is like:
+                   MTD
+         ------------------------
+              SPI NOR framework
+         ------------------------
+                  m25p80
+         ------------------------
+	       SPI bus driver
+         ------------------------
+	       SPI NOR chip
+
+  With the SPI NOR controller driver (Freescale QuadSPI), it looks like:
+                   MTD
+         ------------------------
+              SPI NOR framework
+         ------------------------
+                fsl-quadSPI
+         ------------------------
+	       SPI NOR chip
+
+Part III - How can drivers use the framework?
+---------------------------------------------
+
+The main API is spi_nor_scan(). Before you call the hook, a driver should
+initialize the necessary fields for spi_nor{}. Please see
+drivers/mtd/spi-nor/spi-nor.c for detail. Please also refer to fsl-quadspi.c
+when you want to write a new driver for a SPI NOR controller.