[PATCH v6 0/6] mtd: rawnand: add NVIDIA Tegra NAND flash support

[PATCH v6 0/6] mtd: rawnand: add NVIDIA Tegra NAND flash support

[Stefan Agner]

This sixth revision only removes extra OOB byte support when using
HW ECC. The previous implementation did place the ECC bytes at a
different location depending on whether extra OOB bytes were written.
This does not work well with the MTD subsystem. Since UBI/UBIFS does
not require extra OOB bytes I descided to not provide extra OOB
support for now.

--
Stefan

Changes since v1:
- Split controller and NAND chip structure
- Add BCH support
- Allow to select algorithm and strength using device tree
- Improve HW ECC error reporting and use DEC_STATUS_BUF only
- Use SPDX license identifier
- Use per algorithm mtd_ooblayout_ops
- Use setup_data_interface callback for NAND timing configuration

Changes since v2:
- Set clock rate using assigned-clocks
- Use BIT() macro
- Fix and improve timing calculation
- Improve ECC error handling
- Store OOB layout for tag area in Tegra chip structure
- Update/fix bindings
- Use more specific variable names (replace "value")
- Introduce nand-is-boot-medium
- Choose sensible ECC strenght automatically
- Use wait_for_completion_timeout
- Print register dump on completion timeout
- Unify tegra_nand_(read|write)_page in tegra_nand_page_xfer

Changes since v3:
- Implement tegra_nand_(read|write)_raw using DMA
- Implement tegra_nand_(read|write)_oob using DMA
- Name registers according to Tegra 2 Technical Reference Manual (v02p)
- Use wait_for_completion_io_timeout to account for IO
- Get chip select id from device tree reg property
- Clear interrupts and reinit wait queues in case command/DMA times out
- Set default MTD name after nand_set_flash_node
- Move MODULE_DEVICE_TABLE after declaration of tegra_nand_of_match
- Make (rs|bch)_strength static

Changes since v4:
- Pass OOB area to nand_check_erased_ecc_chunk
- Pass algorithm specific bits_per_step to tegra_nand_get_strength
- Store ECC layout in chip structure
- Fix pointer assignment (use NULL)
- Removed obsolete header delay.h
- Fixed newlines
- Use non-_io variant of wait_for_completion_timeout

Changes since v5:
- Drop extra OOB bytes support

Lucas Stach (1):
  ARM: dts: tegra: add Tegra20 NAND flash controller node

Stefan Agner (5):
  mtd: rawnand: add Reed-Solomon error correction algorithm
  mtd: rawnand: add an option to specify NAND chip as a boot device
  mtd: rawnand: tegra: add devicetree binding
  mtd: rawnand: add NVIDIA Tegra NAND Flash controller driver
  ARM: dts: tegra: enable NAND flash on Colibri T20

 .../devicetree/bindings/mtd/nand.txt          |    6 +-
 .../bindings/mtd/nvidia-tegra20-nand.txt      |   64 +
 MAINTAINERS                                   |    7 +
 arch/arm/boot/dts/tegra20-colibri-512.dtsi    |   16 +
 arch/arm/boot/dts/tegra20.dtsi                |   15 +
 drivers/mtd/nand/raw/Kconfig                  |    6 +
 drivers/mtd/nand/raw/Makefile                 |    1 +
 drivers/mtd/nand/raw/nand_base.c              |    4 +
 drivers/mtd/nand/raw/tegra_nand.c             | 1225 +++++++++++++++++
 include/linux/mtd/rawnand.h                   |    7 +
 10 files changed, 1350 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt
 create mode 100644 drivers/mtd/nand/raw/tegra_nand.c

-- 
2.17.1

[PATCH v6 1/6] mtd: rawnand: add Reed-Solomon error correction algorithm

[Stefan Agner]

Add Reed-Solomon (RS) to the enumeration of ECC algorithms.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/mtd/nand.txt | 2 +-
 drivers/mtd/nand/raw/nand_base.c               | 1 +
 include/linux/mtd/rawnand.h                    | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mtd/nand.txt b/Documentation/devicetree/bindings/mtd/nand.txt
index 8bb11d809429d..eaef8c657aa5c 100644
--- a/Documentation/devicetree/bindings/mtd/nand.txt
+++ b/Documentation/devicetree/bindings/mtd/nand.txt
@@ -25,7 +25,7 @@ Optional NAND chip properties:
 		  Deprecated values:
 		  "soft_bch": use "soft" and nand-ecc-algo instead
 - nand-ecc-algo: string, algorithm of NAND ECC.
-		 Supported values are: "hamming", "bch".
+		 Valid values are: "hamming", "bch", "rs".
 - nand-bus-width : 8 or 16 bus width if not present 8
 - nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
 
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 10c4f9919850c..47e9cb9063da4 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -5777,6 +5777,7 @@ static int of_get_nand_ecc_mode(struct device_node *np)
 static const char * const nand_ecc_algos[] = {
 	[NAND_ECC_HAMMING]	= "hamming",
 	[NAND_ECC_BCH]		= "bch",
+	[NAND_ECC_RS]		= "rs",
 };
 
 static int of_get_nand_ecc_algo(struct device_node *np)
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index 3e8ec3b8a39c7..2d9cb7acbc3d8 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -121,6 +121,7 @@ enum nand_ecc_algo {
 	NAND_ECC_UNKNOWN,
 	NAND_ECC_HAMMING,
 	NAND_ECC_BCH,
+	NAND_ECC_RS,
 };
 
 /*
-- 
2.17.1

[PATCH v6 2/6] mtd: rawnand: add an option to specify NAND chip as a boot device

[Stefan Agner]

Allow to define a NAND chip as a boot device. This can be helpful
for the selection of the ECC algorithm and strength in case the boot
ROM supports only a subset of controller provided options.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
---
 Documentation/devicetree/bindings/mtd/nand.txt | 4 ++++
 drivers/mtd/nand/raw/nand_base.c               | 3 +++
 include/linux/mtd/rawnand.h                    | 6 ++++++
 3 files changed, 13 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/nand.txt b/Documentation/devicetree/bindings/mtd/nand.txt
index eaef8c657aa5c..e949c778e9837 100644
--- a/Documentation/devicetree/bindings/mtd/nand.txt
+++ b/Documentation/devicetree/bindings/mtd/nand.txt
@@ -43,6 +43,10 @@ Optional NAND chip properties:
 		     This is particularly useful when only the in-band area is
 		     used by the upper layers, and you want to make your NAND
 		     as reliable as possible.
+- nand-is-boot-medium: Whether the NAND chip is a boot medium. Drivers might use
+		       this information to select ECC algorithms supported by
+		       the boot ROM or similar restrictions.
+
 - nand-rb: shall contain the native Ready/Busy ids.
 
 The ECC strength and ECC step size properties define the correction capability
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 47e9cb9063da4..e70bf328c64e4 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -5859,6 +5859,9 @@ static int nand_dt_init(struct nand_chip *chip)
 	if (of_get_nand_bus_width(dn) == 16)
 		chip->options |= NAND_BUSWIDTH_16;
 
+	if (of_property_read_bool(dn, "nand-is-boot-medium"))
+		chip->options |= NAND_IS_BOOT_MEDIUM;
+
 	if (of_get_nand_on_flash_bbt(dn))
 		chip->bbt_options |= NAND_BBT_USE_FLASH;
 
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index 2d9cb7acbc3d8..80aeeca03f36b 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -219,6 +219,12 @@ enum nand_ecc_algo {
  */
 #define NAND_WAIT_TCCS		0x00200000
 
+/*
+ * Whether the NAND chip is a boot medium. Drivers might use this information
+ * to select ECC algorithms supported by the boot ROM or similar restrictions.
+ */
+#define NAND_IS_BOOT_MEDIUM	0x00400000
+
 /* Options set by nand scan */
 /* Nand scan has allocated controller struct */
 #define NAND_CONTROLLER_ALLOC	0x80000000
-- 
2.17.1

[PATCH v6 3/6] mtd: rawnand: tegra: add devicetree binding

[Stefan Agner]

This adds the devicetree binding for the Tegra 2 NAND flash
controller.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/mtd/nvidia-tegra20-nand.txt      | 64 +++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt

diff --git a/Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt b/Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt
new file mode 100644
index 0000000000000..1c351362f3a96
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt
@@ -0,0 +1,64 @@
+NVIDIA Tegra NAND Flash controller
+
+Required properties:
+- compatible: Must be one of:
+  - "nvidia,tegra20-nand"
+- reg: MMIO address range
+- interrupts: interrupt output of the NFC controller
+- clocks: Must contain an entry for each entry in clock-names.
+  See ../clocks/clock-bindings.txt for details.
+- clock-names: Must include the following entries:
+  - nand
+- resets: Must contain an entry for each entry in reset-names.
+  See ../reset/reset.txt for details.
+- reset-names: Must include the following entries:
+  - nand
+
+Optional children nodes:
+Individual NAND chips are children of the NAND controller node. Currently
+only one NAND chip supported.
+
+Required children node properties:
+- reg: An integer ranging from 1 to 6 representing the CS line to use.
+
+Optional children node properties:
+- nand-ecc-mode: String, operation mode of the NAND ecc mode. Currently only
+		 "hw" is supported.
+- nand-ecc-algo: string, algorithm of NAND ECC.
+		 Supported values with "hw" ECC mode are: "rs", "bch".
+- nand-bus-width : See nand.txt
+- nand-on-flash-bbt: See nand.txt
+- nand-ecc-strength: integer representing the number of bits to correct
+		     per ECC step (always 512). Supported strength using HW ECC
+		     modes are:
+		     - RS: 4, 6, 8
+		     - BCH: 4, 8, 14, 16
+- nand-ecc-maximize: See nand.txt
+- nand-is-boot-medium: Makes sure only ECC strengths supported by the boot ROM
+		       are choosen.
+- wp-gpios: GPIO specifier for the write protect pin.
+
+Optional child node of NAND chip nodes:
+Partitions: see partition.txt
+
+  Example:
+	nand-controller@70008000 {
+		compatible = "nvidia,tegra20-nand";
+		reg = <0x70008000 0x100>;
+		interrupts = <GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&tegra_car TEGRA20_CLK_NDFLASH>;
+		clock-names = "nand";
+		resets = <&tegra_car 13>;
+		reset-names = "nand";
+
+		nand@0 {
+			reg = <0>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			nand-bus-width = <8>;
+			nand-on-flash-bbt;
+			nand-ecc-algo = "bch";
+			nand-ecc-strength = <8>;
+			wp-gpios = <&gpio TEGRA_GPIO(S, 0) GPIO_ACTIVE_LOW>;
+		};
+	};
-- 
2.17.1


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

[PATCH v6 3/6] mtd: rawnand: tegra: add devicetree binding

[Stefan Agner]

This adds the devicetree binding for the Tegra 2 NAND flash
controller.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/mtd/nvidia-tegra20-nand.txt      | 64 +++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt

diff --git a/Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt b/Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt
new file mode 100644
index 0000000000000..1c351362f3a96
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt
@@ -0,0 +1,64 @@
+NVIDIA Tegra NAND Flash controller
+
+Required properties:
+- compatible: Must be one of:
+  - "nvidia,tegra20-nand"
+- reg: MMIO address range
+- interrupts: interrupt output of the NFC controller
+- clocks: Must contain an entry for each entry in clock-names.
+  See ../clocks/clock-bindings.txt for details.
+- clock-names: Must include the following entries:
+  - nand
+- resets: Must contain an entry for each entry in reset-names.
+  See ../reset/reset.txt for details.
+- reset-names: Must include the following entries:
+  - nand
+
+Optional children nodes:
+Individual NAND chips are children of the NAND controller node. Currently
+only one NAND chip supported.
+
+Required children node properties:
+- reg: An integer ranging from 1 to 6 representing the CS line to use.
+
+Optional children node properties:
+- nand-ecc-mode: String, operation mode of the NAND ecc mode. Currently only
+		 "hw" is supported.
+- nand-ecc-algo: string, algorithm of NAND ECC.
+		 Supported values with "hw" ECC mode are: "rs", "bch".
+- nand-bus-width : See nand.txt
+- nand-on-flash-bbt: See nand.txt
+- nand-ecc-strength: integer representing the number of bits to correct
+		     per ECC step (always 512). Supported strength using HW ECC
+		     modes are:
+		     - RS: 4, 6, 8
+		     - BCH: 4, 8, 14, 16
+- nand-ecc-maximize: See nand.txt
+- nand-is-boot-medium: Makes sure only ECC strengths supported by the boot ROM
+		       are choosen.
+- wp-gpios: GPIO specifier for the write protect pin.
+
+Optional child node of NAND chip nodes:
+Partitions: see partition.txt
+
+  Example:
+	nand-controller@70008000 {
+		compatible = "nvidia,tegra20-nand";
+		reg = <0x70008000 0x100>;
+		interrupts = <GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&tegra_car TEGRA20_CLK_NDFLASH>;
+		clock-names = "nand";
+		resets = <&tegra_car 13>;
+		reset-names = "nand";
+
+		nand@0 {
+			reg = <0>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			nand-bus-width = <8>;
+			nand-on-flash-bbt;
+			nand-ecc-algo = "bch";
+			nand-ecc-strength = <8>;
+			wp-gpios = <&gpio TEGRA_GPIO(S, 0) GPIO_ACTIVE_LOW>;
+		};
+	};
-- 
2.17.1

[PATCH v6 4/6] mtd: rawnand: add NVIDIA Tegra NAND Flash controller driver

[Stefan Agner]

Add support for the NAND flash controller found on NVIDIA
Tegra 2 SoCs. This implementation does not make use of the
command queue feature. Regular operations using ->exec_op()
use PIO mode for data transfers. Raw, ECC and OOB read/writes
make use of the DMA mode for data transfer.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
---
 MAINTAINERS                       |    7 +
 drivers/mtd/nand/raw/Kconfig      |    6 +
 drivers/mtd/nand/raw/Makefile     |    1 +
 drivers/mtd/nand/raw/tegra_nand.c | 1225 +++++++++++++++++++++++++++++
 4 files changed, 1239 insertions(+)
 create mode 100644 drivers/mtd/nand/raw/tegra_nand.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 9d5eeff51b5fd..d62bf7dc714d2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14040,6 +14040,13 @@ M:	Laxman Dewangan <ldewangan@nvidia.com>
 S:	Supported
 F:	drivers/input/keyboard/tegra-kbc.c
 
+TEGRA NAND DRIVER
+M:	Stefan Agner <stefan@agner.ch>
+M:	Lucas Stach <dev@lynxeye.de>
+S:	Maintained
+F:	Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt
+F:	drivers/mtd/nand/raw/tegra_nand.c
+
 TEGRA PWM DRIVER
 M:	Thierry Reding <thierry.reding@gmail.com>
 S:	Supported
diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index 6871ff0fd300b..472a870cfe4b0 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -530,4 +530,10 @@ config MTD_NAND_MTK
 	  Enables support for NAND controller on MTK SoCs.
 	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
 
+config MTD_NAND_TEGRA
+	tristate "Support for NAND controller on NVIDIA Tegra"
+	depends on ARCH_TEGRA || COMPILE_TEST
+	help
+	  Enables support for NAND flash controller on NVIDIA Tegra SoC.
+
 endif # MTD_NAND
diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
index 165b7ef9e9a18..d5a5f9832b887 100644
--- a/drivers/mtd/nand/raw/Makefile
+++ b/drivers/mtd/nand/raw/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
 obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
 obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
 obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
+obj-$(CONFIG_MTD_NAND_TEGRA)		+= tegra_nand.o
 
 nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o
 nand-objs += nand_amd.o
diff --git a/drivers/mtd/nand/raw/tegra_nand.c b/drivers/mtd/nand/raw/tegra_nand.c
new file mode 100644
index 0000000000000..c3df085b362f1
--- /dev/null
+++ b/drivers/mtd/nand/raw/tegra_nand.c
@@ -0,0 +1,1225 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Stefan Agner <stefan@agner.ch>
+ * Copyright (C) 2014-2015 Lucas Stach <dev@lynxeye.de>
+ * Copyright (C) 2012 Avionic Design GmbH
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#define COMMAND					0x00
+#define   COMMAND_GO				BIT(31)
+#define   COMMAND_CLE				BIT(30)
+#define   COMMAND_ALE				BIT(29)
+#define   COMMAND_PIO				BIT(28)
+#define   COMMAND_TX				BIT(27)
+#define   COMMAND_RX				BIT(26)
+#define   COMMAND_SEC_CMD			BIT(25)
+#define   COMMAND_AFT_DAT			BIT(24)
+#define   COMMAND_TRANS_SIZE(x)			(((x - 1) & 0xf) << 20)
+#define   COMMAND_A_VALID			BIT(19)
+#define   COMMAND_B_VALID			BIT(18)
+#define   COMMAND_RD_STATUS_CHK			BIT(17)
+#define   COMMAND_RBSY_CHK			BIT(16)
+#define   COMMAND_CE(x)				BIT(8 + ((x) & 0x7))
+#define   COMMAND_CLE_SIZE(x)			(((x - 1) & 0x3) << 4)
+#define   COMMAND_ALE_SIZE(x)			(((x - 1) & 0xf) << 0)
+
+#define STATUS					0x04
+
+#define ISR					0x08
+#define   ISR_CORRFAIL_ERR			BIT(24)
+#define   ISR_UND				BIT(7)
+#define   ISR_OVR				BIT(6)
+#define   ISR_CMD_DONE				BIT(5)
+#define   ISR_ECC_ERR				BIT(4)
+
+#define IER					0x0c
+#define   IER_ERR_TRIG_VAL(x)			(((x) & 0xf) << 16)
+#define   IER_UND				BIT(7)
+#define   IER_OVR				BIT(6)
+#define   IER_CMD_DONE				BIT(5)
+#define   IER_ECC_ERR				BIT(4)
+#define   IER_GIE				BIT(0)
+
+#define CONFIG					0x10
+#define   CONFIG_HW_ECC				BIT(31)
+#define   CONFIG_ECC_SEL			BIT(30)
+#define   CONFIG_ERR_COR			BIT(29)
+#define   CONFIG_PIPE_EN			BIT(28)
+#define   CONFIG_TVAL_4				(0 << 24)
+#define   CONFIG_TVAL_6				(1 << 24)
+#define   CONFIG_TVAL_8				(2 << 24)
+#define   CONFIG_SKIP_SPARE			BIT(23)
+#define   CONFIG_BUS_WIDTH_16			BIT(21)
+#define   CONFIG_COM_BSY			BIT(20)
+#define   CONFIG_PS_256				(0 << 16)
+#define   CONFIG_PS_512				(1 << 16)
+#define   CONFIG_PS_1024			(2 << 16)
+#define   CONFIG_PS_2048			(3 << 16)
+#define   CONFIG_PS_4096			(4 << 16)
+#define   CONFIG_SKIP_SPARE_SIZE_4		(0 << 14)
+#define   CONFIG_SKIP_SPARE_SIZE_8		(1 << 14)
+#define   CONFIG_SKIP_SPARE_SIZE_12		(2 << 14)
+#define   CONFIG_SKIP_SPARE_SIZE_16		(3 << 14)
+#define   CONFIG_TAG_BYTE_SIZE(x)			((x) & 0xff)
+
+#define TIMING_1				0x14
+#define   TIMING_TRP_RESP(x)			(((x) & 0xf) << 28)
+#define   TIMING_TWB(x)				(((x) & 0xf) << 24)
+#define   TIMING_TCR_TAR_TRR(x)			(((x) & 0xf) << 20)
+#define   TIMING_TWHR(x)			(((x) & 0xf) << 16)
+#define   TIMING_TCS(x)				(((x) & 0x3) << 14)
+#define   TIMING_TWH(x)				(((x) & 0x3) << 12)
+#define   TIMING_TWP(x)				(((x) & 0xf) <<  8)
+#define   TIMING_TRH(x)				(((x) & 0x3) <<  4)
+#define   TIMING_TRP(x)				(((x) & 0xf) <<  0)
+
+#define RESP					0x18
+
+#define TIMING_2				0x1c
+#define   TIMING_TADL(x)			((x) & 0xf)
+
+#define CMD_REG1				0x20
+#define CMD_REG2				0x24
+#define ADDR_REG1				0x28
+#define ADDR_REG2				0x2c
+
+#define DMA_MST_CTRL				0x30
+#define   DMA_MST_CTRL_GO			BIT(31)
+#define   DMA_MST_CTRL_IN			(0 << 30)
+#define   DMA_MST_CTRL_OUT			BIT(30)
+#define   DMA_MST_CTRL_PERF_EN			BIT(29)
+#define   DMA_MST_CTRL_IE_DONE			BIT(28)
+#define   DMA_MST_CTRL_REUSE			BIT(27)
+#define   DMA_MST_CTRL_BURST_1			(2 << 24)
+#define   DMA_MST_CTRL_BURST_4			(3 << 24)
+#define   DMA_MST_CTRL_BURST_8			(4 << 24)
+#define   DMA_MST_CTRL_BURST_16			(5 << 24)
+#define   DMA_MST_CTRL_IS_DONE			BIT(20)
+#define   DMA_MST_CTRL_EN_A			BIT(2)
+#define   DMA_MST_CTRL_EN_B			BIT(1)
+
+#define DMA_CFG_A				0x34
+#define DMA_CFG_B				0x38
+
+#define FIFO_CTRL				0x3c
+#define   FIFO_CTRL_CLR_ALL			BIT(3)
+
+#define DATA_PTR				0x40
+#define TAG_PTR					0x44
+#define ECC_PTR					0x48
+
+#define DEC_STATUS				0x4c
+#define   DEC_STATUS_A_ECC_FAIL			BIT(1)
+#define   DEC_STATUS_ERR_COUNT_MASK		0x00ff0000
+#define   DEC_STATUS_ERR_COUNT_SHIFT		16
+
+#define HWSTATUS_CMD				0x50
+#define HWSTATUS_MASK				0x54
+#define   HWSTATUS_RDSTATUS_MASK(x)		(((x) & 0xff) << 24)
+#define   HWSTATUS_RDSTATUS_VALUE(x)		(((x) & 0xff) << 16)
+#define   HWSTATUS_RBSY_MASK(x)			(((x) & 0xff) << 8)
+#define   HWSTATUS_RBSY_VALUE(x)		(((x) & 0xff) << 0)
+
+#define BCH_CONFIG				0xcc
+#define   BCH_ENABLE				BIT(0)
+#define   BCH_TVAL_4				(0 << 4)
+#define   BCH_TVAL_8				(1 << 4)
+#define   BCH_TVAL_14				(2 << 4)
+#define   BCH_TVAL_16				(3 << 4)
+
+#define DEC_STAT_RESULT				0xd0
+#define DEC_STAT_BUF				0xd4
+#define   DEC_STAT_BUF_FAIL_SEC_FLAG_MASK	0xff000000
+#define   DEC_STAT_BUF_FAIL_SEC_FLAG_SHIFT	24
+#define   DEC_STAT_BUF_CORR_SEC_FLAG_MASK	0x00ff0000
+#define   DEC_STAT_BUF_CORR_SEC_FLAG_SHIFT	16
+#define   DEC_STAT_BUF_MAX_CORR_CNT_MASK	0x00001f00
+#define   DEC_STAT_BUF_MAX_CORR_CNT_SHIFT	8
+
+#define OFFSET(val, off)	((val) < (off) ? 0 : (val) - (off))
+
+#define SKIP_SPARE_BYTES	4
+#define BITS_PER_STEP_RS	18
+#define BITS_PER_STEP_BCH	13
+
+#define INT_MASK		(IER_UND | IER_OVR | IER_CMD_DONE | IER_GIE)
+#define HWSTATUS_CMD_DEFAULT	NAND_STATUS_READY
+#define HWSTATUS_MASK_DEFAULT	(HWSTATUS_RDSTATUS_MASK(1) | \
+				HWSTATUS_RDSTATUS_VALUE(0) | \
+				HWSTATUS_RBSY_MASK(NAND_STATUS_READY) | \
+				HWSTATUS_RBSY_VALUE(NAND_STATUS_READY))
+
+struct tegra_nand_controller {
+	struct nand_hw_control controller;
+	struct device *dev;
+	void __iomem *regs;
+	int irq;
+	struct clk *clk;
+	struct completion command_complete;
+	struct completion dma_complete;
+	bool last_read_error;
+	int cur_cs;
+	struct nand_chip *chip;
+};
+
+struct tegra_nand_chip {
+	struct nand_chip chip;
+	struct gpio_desc *wp_gpio;
+	struct mtd_oob_region ecc;
+	u32 config;
+	u32 config_ecc;
+	u32 bch_config;
+	int cs[1];
+};
+
+static inline struct tegra_nand_controller *to_tegra_ctrl(
+						struct nand_hw_control *hw_ctrl)
+{
+	return container_of(hw_ctrl, struct tegra_nand_controller, controller);
+}
+
+static inline struct tegra_nand_chip *to_tegra_chip(struct nand_chip *chip)
+{
+	return container_of(chip, struct tegra_nand_chip, chip);
+}
+
+static int tegra_nand_ooblayout_rs_ecc(struct mtd_info *mtd, int section,
+				       struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int bytes_per_step = DIV_ROUND_UP(BITS_PER_STEP_RS * chip->ecc.strength,
+					  BITS_PER_BYTE);
+
+	if (section > 0)
+		return -ERANGE;
+
+	oobregion->offset = SKIP_SPARE_BYTES;
+	oobregion->length = round_up(bytes_per_step * chip->ecc.steps, 4);
+
+	return 0;
+}
+
+static int tegra_nand_ooblayout_no_free(struct mtd_info *mtd, int section,
+					struct mtd_oob_region *oobregion)
+{
+	return -ERANGE;
+}
+
+static const struct mtd_ooblayout_ops tegra_nand_oob_rs_ops = {
+	.ecc = tegra_nand_ooblayout_rs_ecc,
+	.free = tegra_nand_ooblayout_no_free,
+};
+
+static int tegra_nand_ooblayout_bch_ecc(struct mtd_info *mtd, int section,
+				       struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int bytes_per_step = DIV_ROUND_UP(BITS_PER_STEP_BCH * chip->ecc.strength,
+					  BITS_PER_BYTE);
+
+	if (section > 0)
+		return -ERANGE;
+
+	oobregion->offset = SKIP_SPARE_BYTES;
+	oobregion->length = round_up(bytes_per_step * chip->ecc.steps, 4);
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops tegra_nand_oob_bch_ops = {
+	.ecc = tegra_nand_ooblayout_bch_ecc,
+	.free = tegra_nand_ooblayout_no_free,
+};
+
+static irqreturn_t tegra_nand_irq(int irq, void *data)
+{
+	struct tegra_nand_controller *ctrl = data;
+	u32 isr, dma;
+
+	isr = readl_relaxed(ctrl->regs + ISR);
+	dma = readl_relaxed(ctrl->regs + DMA_MST_CTRL);
+	dev_dbg(ctrl->dev, "isr %08x\n", isr);
+
+	if (!isr && !(dma & DMA_MST_CTRL_IS_DONE))
+		return IRQ_NONE;
+
+	/*
+	 * The bit name is somewhat missleading: This is also set when
+	 * HW ECC was successful. The data sheet states:
+	 * Correctable OR Un-correctable errors occurred in the DMA transfer...
+	 */
+	if (isr & ISR_CORRFAIL_ERR)
+		ctrl->last_read_error = true;
+
+	if (isr & ISR_CMD_DONE)
+		complete(&ctrl->command_complete);
+
+	if (isr & ISR_UND)
+		dev_err(ctrl->dev, "FIFO underrun\n");
+
+	if (isr & ISR_OVR)
+		dev_err(ctrl->dev, "FIFO overrun\n");
+
+	/* handle DMA interrupts */
+	if (dma & DMA_MST_CTRL_IS_DONE) {
+		writel_relaxed(dma, ctrl->regs + DMA_MST_CTRL);
+		complete(&ctrl->dma_complete);
+	}
+
+	/* clear interrupts */
+	writel_relaxed(isr, ctrl->regs + ISR);
+
+	return IRQ_HANDLED;
+}
+
+static const char * const tegra_nand_reg_names[] = {
+	"COMMAND",
+	"STATUS",
+	"ISR",
+	"IER",
+	"CONFIG",
+	"TIMING",
+	NULL,
+	"TIMING2",
+	"CMD_REG1",
+	"CMD_REG2",
+	"ADDR_REG1",
+	"ADDR_REG2",
+	"DMA_MST_CTRL",
+	"DMA_CFG_A",
+	"DMA_CFG_B",
+	"FIFO_CTRL",
+};
+
+static void tegra_nand_dump_reg(struct tegra_nand_controller *ctrl)
+{
+	u32 reg;
+	int i;
+
+	dev_err(ctrl->dev, "Tegra NAND controller register dump\n");
+	for (i = 0; i < ARRAY_SIZE(tegra_nand_reg_names); i++) {
+		const char *reg_name = tegra_nand_reg_names[i];
+
+		if (!reg_name)
+			continue;
+
+		reg = readl_relaxed(ctrl->regs + (i * 4));
+		dev_err(ctrl->dev, "%s: 0x%08x\n", reg_name, reg);
+	}
+}
+
+static void tegra_nand_controller_abort(struct tegra_nand_controller *ctrl)
+{
+	u32 isr, dma;
+
+	disable_irq(ctrl->irq);
+
+	/* Abort current command/DMA operation */
+	writel_relaxed(0, ctrl->regs + DMA_MST_CTRL);
+	writel_relaxed(0, ctrl->regs + COMMAND);
+
+	/* clear interrupts */
+	isr = readl_relaxed(ctrl->regs + ISR);
+	writel_relaxed(isr, ctrl->regs + ISR);
+	dma = readl_relaxed(ctrl->regs + DMA_MST_CTRL);
+	writel_relaxed(dma, ctrl->regs + DMA_MST_CTRL);
+
+	reinit_completion(&ctrl->command_complete);
+	reinit_completion(&ctrl->dma_complete);
+
+	enable_irq(ctrl->irq);
+}
+
+static int tegra_nand_cmd(struct nand_chip *chip,
+			 const struct nand_subop *subop)
+{
+	const struct nand_op_instr *instr;
+	const struct nand_op_instr *instr_data_in = NULL;
+	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
+	unsigned int op_id, size = 0, offset = 0;
+	bool first_cmd = true;
+	u32 reg, cmd = 0;
+	int ret;
+
+	for (op_id = 0; op_id < subop->ninstrs; op_id++) {
+		unsigned int naddrs, i;
+		const u8 *addrs;
+		u32 addr1 = 0, addr2 = 0;
+
+		instr = &subop->instrs[op_id];
+
+		switch (instr->type) {
+		case NAND_OP_CMD_INSTR:
+			if (first_cmd) {
+				cmd |= COMMAND_CLE;
+				writel_relaxed(instr->ctx.cmd.opcode,
+					       ctrl->regs + CMD_REG1);
+			} else {
+				cmd |= COMMAND_SEC_CMD;
+				writel_relaxed(instr->ctx.cmd.opcode,
+					       ctrl->regs + CMD_REG2);
+			}
+			first_cmd = false;
+			break;
+
+		case NAND_OP_ADDR_INSTR:
+			offset = nand_subop_get_addr_start_off(subop, op_id);
+			naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
+			addrs = &instr->ctx.addr.addrs[offset];
+
+			cmd |= COMMAND_ALE | COMMAND_ALE_SIZE(naddrs);
+			for (i = 0; i < min_t(unsigned int, 4, naddrs); i++)
+				addr1 |= *addrs++ << (BITS_PER_BYTE * i);
+			naddrs -= i;
+			for (i = 0; i < min_t(unsigned int, 4, naddrs); i++)
+				addr2 |= *addrs++ << (BITS_PER_BYTE * i);
+
+			writel_relaxed(addr1, ctrl->regs + ADDR_REG1);
+			writel_relaxed(addr2, ctrl->regs + ADDR_REG2);
+			break;
+
+		case NAND_OP_DATA_IN_INSTR:
+			size = nand_subop_get_data_len(subop, op_id);
+			offset = nand_subop_get_data_start_off(subop, op_id);
+
+			cmd |= COMMAND_TRANS_SIZE(size) | COMMAND_PIO |
+				COMMAND_RX | COMMAND_A_VALID;
+
+			instr_data_in = instr;
+			break;
+
+		case NAND_OP_DATA_OUT_INSTR:
+			size = nand_subop_get_data_len(subop, op_id);
+			offset = nand_subop_get_data_start_off(subop, op_id);
+
+			cmd |= COMMAND_TRANS_SIZE(size) | COMMAND_PIO |
+				COMMAND_TX | COMMAND_A_VALID;
+			memcpy(&reg, instr->ctx.data.buf.out + offset, size);
+
+			writel_relaxed(reg, ctrl->regs + RESP);
+			break;
+
+		case NAND_OP_WAITRDY_INSTR:
+			cmd |= COMMAND_RBSY_CHK;
+			break;
+		}
+	}
+
+	cmd |= COMMAND_GO | COMMAND_CE(ctrl->cur_cs);
+	writel_relaxed(cmd, ctrl->regs + COMMAND);
+	ret = wait_for_completion_timeout(&ctrl->command_complete,
+					     msecs_to_jiffies(500));
+	if (!ret) {
+		dev_err(ctrl->dev, "COMMAND timeout\n");
+		tegra_nand_dump_reg(ctrl);
+		tegra_nand_controller_abort(ctrl);
+		return -ETIMEDOUT;
+	}
+
+	if (instr_data_in) {
+		reg = readl_relaxed(ctrl->regs + RESP);
+		memcpy(instr_data_in->ctx.data.buf.in + offset, &reg, size);
+	}
+
+	return 0;
+}
+
+static const struct nand_op_parser tegra_nand_op_parser = NAND_OP_PARSER(
+	NAND_OP_PARSER_PATTERN(tegra_nand_cmd,
+		NAND_OP_PARSER_PAT_CMD_ELEM(true),
+		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
+		NAND_OP_PARSER_PAT_CMD_ELEM(true),
+		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
+	NAND_OP_PARSER_PATTERN(tegra_nand_cmd,
+		NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 4)),
+	NAND_OP_PARSER_PATTERN(tegra_nand_cmd,
+		NAND_OP_PARSER_PAT_CMD_ELEM(true),
+		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
+		NAND_OP_PARSER_PAT_CMD_ELEM(true),
+		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
+		NAND_OP_PARSER_PAT_DATA_IN_ELEM(true, 4)),
+	);
+
+static int tegra_nand_exec_op(struct nand_chip *chip,
+			     const struct nand_operation *op,
+			     bool check_only)
+{
+	return nand_op_parser_exec_op(chip, &tegra_nand_op_parser, op,
+				      check_only);
+}
+
+static void tegra_nand_select_chip(struct mtd_info *mtd, int die_nr)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct tegra_nand_chip *nand = to_tegra_chip(chip);
+	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
+
+	if (die_nr < 0 || die_nr > 1) {
+		ctrl->cur_cs = -1;
+		return;
+	}
+
+	ctrl->cur_cs = nand->cs[die_nr];
+}
+
+static void tegra_nand_hw_ecc(struct tegra_nand_controller *ctrl,
+			      struct nand_chip *chip, bool enable)
+{
+	struct tegra_nand_chip *nand = to_tegra_chip(chip);
+
+	if (chip->ecc.algo == NAND_ECC_BCH && enable)
+		writel_relaxed(nand->bch_config, ctrl->regs + BCH_CONFIG);
+	else
+		writel_relaxed(0, ctrl->regs + BCH_CONFIG);
+
+	if (enable)
+		writel_relaxed(nand->config_ecc, ctrl->regs + CONFIG);
+	else
+		writel_relaxed(nand->config, ctrl->regs + CONFIG);
+}
+
+static int tegra_nand_page_xfer(struct mtd_info *mtd, struct nand_chip *chip,
+				void *buf, void *oob_buf, int oob_len, int page,
+				bool read)
+{
+	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
+	enum dma_data_direction dir = read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	dma_addr_t dma_addr = 0, dma_addr_oob = 0;
+	u32 addr1, cmd, dma_ctrl;
+	int ret;
+
+	if (read) {
+		writel_relaxed(NAND_CMD_READ0, ctrl->regs + CMD_REG1);
+		writel_relaxed(NAND_CMD_READSTART, ctrl->regs + CMD_REG2);
+	} else {
+		writel_relaxed(NAND_CMD_SEQIN, ctrl->regs + CMD_REG1);
+		writel_relaxed(NAND_CMD_PAGEPROG, ctrl->regs + CMD_REG2);
+	}
+	cmd = COMMAND_CLE | COMMAND_SEC_CMD;
+
+	/* Lower 16-bits are column, by default 0 */
+	addr1 = page << 16;
+
+	if (!buf)
+		addr1 |= mtd->writesize;
+	writel_relaxed(addr1, ctrl->regs + ADDR_REG1);
+
+	if (chip->options & NAND_ROW_ADDR_3) {
+		writel_relaxed(page >> 16, ctrl->regs + ADDR_REG2);
+		cmd |= COMMAND_ALE | COMMAND_ALE_SIZE(5);
+	} else {
+		cmd |= COMMAND_ALE | COMMAND_ALE_SIZE(4);
+	}
+
+	if (buf) {
+		dma_addr = dma_map_single(ctrl->dev, buf, mtd->writesize, dir);
+		ret = dma_mapping_error(ctrl->dev, dma_addr);
+		if (ret) {
+			dev_err(ctrl->dev, "dma mapping error\n");
+			return -EINVAL;
+		}
+
+		writel_relaxed(mtd->writesize - 1, ctrl->regs + DMA_CFG_A);
+		writel_relaxed(dma_addr, ctrl->regs + DATA_PTR);
+	}
+
+	if (oob_buf) {
+		dma_addr_oob = dma_map_single(ctrl->dev, oob_buf, mtd->oobsize,
+					      dir);
+		ret = dma_mapping_error(ctrl->dev, dma_addr_oob);
+		if (ret) {
+			dev_err(ctrl->dev, "dma mapping error\n");
+			ret = -EINVAL;
+			goto err_unmap_dma_page;
+		}
+
+		writel_relaxed(oob_len - 1, ctrl->regs + DMA_CFG_B);
+		writel_relaxed(dma_addr_oob, ctrl->regs + TAG_PTR);
+	}
+
+	dma_ctrl = DMA_MST_CTRL_GO | DMA_MST_CTRL_PERF_EN |
+		   DMA_MST_CTRL_IE_DONE | DMA_MST_CTRL_IS_DONE |
+		   DMA_MST_CTRL_BURST_16;
+
+	if (buf)
+		dma_ctrl |= DMA_MST_CTRL_EN_A;
+	if (oob_buf)
+		dma_ctrl |= DMA_MST_CTRL_EN_B;
+
+	if (read)
+		dma_ctrl |= DMA_MST_CTRL_IN | DMA_MST_CTRL_REUSE;
+	else
+		dma_ctrl |= DMA_MST_CTRL_OUT;
+
+	writel_relaxed(dma_ctrl, ctrl->regs + DMA_MST_CTRL);
+
+	cmd |= COMMAND_GO | COMMAND_RBSY_CHK | COMMAND_TRANS_SIZE(9) |
+	       COMMAND_CE(ctrl->cur_cs);
+
+	if (buf)
+		cmd |= COMMAND_A_VALID;
+	if (oob_buf)
+		cmd |= COMMAND_B_VALID;
+
+	if (read)
+		cmd |= COMMAND_RX;
+	else
+		cmd |= COMMAND_TX | COMMAND_AFT_DAT;
+
+	writel_relaxed(cmd, ctrl->regs + COMMAND);
+
+	ret = wait_for_completion_timeout(&ctrl->command_complete,
+					     msecs_to_jiffies(500));
+	if (!ret) {
+		dev_err(ctrl->dev, "COMMAND timeout\n");
+		tegra_nand_dump_reg(ctrl);
+		tegra_nand_controller_abort(ctrl);
+		ret = -ETIMEDOUT;
+		goto err_unmap_dma;
+	}
+
+	ret = wait_for_completion_timeout(&ctrl->dma_complete,
+					     msecs_to_jiffies(500));
+	if (!ret) {
+		dev_err(ctrl->dev, "DMA timeout\n");
+		tegra_nand_dump_reg(ctrl);
+		tegra_nand_controller_abort(ctrl);
+		ret = -ETIMEDOUT;
+		goto err_unmap_dma;
+	}
+	ret = 0;
+
+err_unmap_dma:
+	if (oob_buf)
+		dma_unmap_single(ctrl->dev, dma_addr_oob, mtd->oobsize, dir);
+err_unmap_dma_page:
+	if (buf)
+		dma_unmap_single(ctrl->dev, dma_addr, mtd->writesize, dir);
+
+	return ret;
+}
+
+static int tegra_nand_read_page_raw(struct mtd_info *mtd,
+				    struct nand_chip *chip,
+				    uint8_t *buf, int oob_required, int page)
+{
+	void *oob_buf = oob_required ? chip->oob_poi : NULL;
+
+	return tegra_nand_page_xfer(mtd, chip, buf, oob_buf,
+				    mtd->oobsize, page, true);
+}
+
+static int tegra_nand_write_page_raw(struct mtd_info *mtd,
+				     struct nand_chip *chip,
+				     const uint8_t *buf, int oob_required,
+				     int page)
+{
+	void *oob_buf = oob_required ? chip->oob_poi : NULL;
+
+	return tegra_nand_page_xfer(mtd, chip, (void *)buf, oob_buf,
+				     mtd->oobsize, page, false);
+}
+
+static int tegra_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
+			       int page)
+{
+	return tegra_nand_page_xfer(mtd, chip, NULL, chip->oob_poi,
+				    mtd->oobsize, page, true);
+}
+
+static int tegra_nand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
+				int page)
+{
+	return tegra_nand_page_xfer(mtd, chip, NULL, chip->oob_poi,
+				    mtd->oobsize, page, false);
+}
+
+static int tegra_nand_read_page_hwecc(struct mtd_info *mtd,
+				      struct nand_chip *chip,
+				      uint8_t *buf, int oob_required, int page)
+{
+	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
+	struct tegra_nand_chip *nand = to_tegra_chip(chip);
+	void *oob_buf = oob_required ? chip->oob_poi : NULL;
+	u32 dec_stat, max_corr_cnt;
+	unsigned long fail_sec_flag;
+	int ret;
+
+	tegra_nand_hw_ecc(ctrl, chip, true);
+	ret = tegra_nand_page_xfer(mtd, chip, buf, oob_buf, 0, page, true);
+	tegra_nand_hw_ecc(ctrl, chip, false);
+	if (ret)
+		return ret;
+
+	/* No correctable or un-correctable errors, page must have 0 bitflips */
+	if (!ctrl->last_read_error)
+		return 0;
+
+	/*
+	 * Correctable or un-correctable errors occurred. Use DEC_STAT_BUF
+	 * which contains information for all ECC selections.
+	 *
+	 * Note that since we do not use Command Queues DEC_RESULT does not
+	 * state the number of pages we can read from the DEC_STAT_BUF. But
+	 * since CORRFAIL_ERR did occur during page read we do have a valid
+	 * result in DEC_STAT_BUF.
+	 */
+	ctrl->last_read_error = false;
+	dec_stat = readl_relaxed(ctrl->regs + DEC_STAT_BUF);
+
+	fail_sec_flag = (dec_stat & DEC_STAT_BUF_FAIL_SEC_FLAG_MASK) >>
+			DEC_STAT_BUF_FAIL_SEC_FLAG_SHIFT;
+
+	max_corr_cnt = (dec_stat & DEC_STAT_BUF_MAX_CORR_CNT_MASK) >>
+		       DEC_STAT_BUF_MAX_CORR_CNT_SHIFT;
+
+	if (fail_sec_flag) {
+		int bit, max_bitflips = 0;
+
+		/*
+		 * Since we do not support subpage writes, a complete page
+		 * is either written or not. We can take a shortcut here by
+		 * checking wheather any of the sector has been successful
+		 * read. If at least one sectors has been read successfully,
+		 * the page must have been a written previously. It cannot
+		 * be an erased page.
+		 *
+		 * E.g. controller might return fail_sec_flag with 0x4, which
+		 * would mean only the third sector failed to correct. The
+		 * page must have been written and the third sector is really
+		 * not correctable anymore.
+		 */
+		if (fail_sec_flag ^ GENMASK(chip->ecc.steps - 1, 0)) {
+			mtd->ecc_stats.failed += hweight8(fail_sec_flag);
+			return max_corr_cnt;
+		}
+
+		/*
+		 * All sectors failed to correct, but the ECC isn't smart
+		 * enough to figure out if a page is really just erased.
+		 * Read OOB data and check whether data/OOB is completely
+		 * erased or if error correction just failed for all sub-
+		 * pages.
+		 */
+		ret = tegra_nand_read_oob(mtd, chip, page);
+		if (ret < 0)
+			return ret;
+
+		for_each_set_bit(bit, &fail_sec_flag, chip->ecc.steps) {
+			u8 *data = buf + (chip->ecc.size * bit);
+			u8 *oob = chip->oob_poi + nand->ecc.offset +
+				  (chip->ecc.bytes * bit);
+
+			ret = nand_check_erased_ecc_chunk(data, chip->ecc.size,
+							  oob, chip->ecc.bytes,
+							  NULL, 0,
+							  chip->ecc.strength);
+			if (ret < 0) {
+				mtd->ecc_stats.failed++;
+			} else {
+				mtd->ecc_stats.corrected += ret;
+				max_bitflips = max(ret, max_bitflips);
+			}
+		}
+
+		return max_t(unsigned int, max_corr_cnt, max_bitflips);
+	} else {
+		int corr_sec_flag;
+
+		corr_sec_flag = (dec_stat & DEC_STAT_BUF_CORR_SEC_FLAG_MASK) >>
+				DEC_STAT_BUF_CORR_SEC_FLAG_SHIFT;
+
+		/*
+		 * The value returned in the register is the maximum of
+		 * bitflips encountered in any of the ECC regions. As there is
+		 * no way to get the number of bitflips in a specific regions
+		 * we are not able to deliver correct stats but instead
+		 * overestimate the number of corrected bitflips by assuming
+		 * that all regions where errors have been corrected
+		 * encountered the maximum number of bitflips.
+		 */
+		mtd->ecc_stats.corrected += max_corr_cnt * hweight8(corr_sec_flag);
+
+		return max_corr_cnt;
+	}
+}
+
+static int tegra_nand_write_page_hwecc(struct mtd_info *mtd,
+				       struct nand_chip *chip,
+				       const uint8_t *buf, int oob_required,
+				       int page)
+{
+	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
+	void *oob_buf = oob_required ? chip->oob_poi : NULL;
+	int ret;
+
+	tegra_nand_hw_ecc(ctrl, chip, true);
+	ret = tegra_nand_page_xfer(mtd, chip, (void *)buf, oob_buf,
+				   0, page, false);
+	tegra_nand_hw_ecc(ctrl, chip, false);
+
+	return ret;
+}
+
+static void tegra_nand_setup_timing(struct tegra_nand_controller *ctrl,
+				    const struct nand_sdr_timings *timings)
+{
+	/*
+	 * The period (and all other timings in this function) is in ps,
+	 * so need to take care here to avoid integer overflows.
+	 */
+	unsigned int rate = clk_get_rate(ctrl->clk) / 1000000;
+	unsigned int period = DIV_ROUND_UP(1000000, rate);
+	u32 val, reg = 0;
+
+	val = DIV_ROUND_UP(max3(timings->tAR_min, timings->tRR_min,
+				timings->tRC_min), period);
+	reg |= TIMING_TCR_TAR_TRR(OFFSET(val, 3));
+
+	val = DIV_ROUND_UP(max(max(timings->tCS_min, timings->tCH_min),
+			       max(timings->tALS_min, timings->tALH_min)),
+			   period);
+	reg |= TIMING_TCS(OFFSET(val, 2));
+
+	val = DIV_ROUND_UP(max(timings->tRP_min, timings->tREA_max) + 6000,
+			   period);
+	reg |= TIMING_TRP(OFFSET(val, 1)) | TIMING_TRP_RESP(OFFSET(val, 1));
+
+	reg |= TIMING_TWB(OFFSET(DIV_ROUND_UP(timings->tWB_max, period), 1));
+	reg |= TIMING_TWHR(OFFSET(DIV_ROUND_UP(timings->tWHR_min, period), 1));
+	reg |= TIMING_TWH(OFFSET(DIV_ROUND_UP(timings->tWH_min, period), 1));
+	reg |= TIMING_TWP(OFFSET(DIV_ROUND_UP(timings->tWP_min, period), 1));
+	reg |= TIMING_TRH(OFFSET(DIV_ROUND_UP(timings->tREH_min, period), 1));
+
+	writel_relaxed(reg, ctrl->regs + TIMING_1);
+
+	val = DIV_ROUND_UP(timings->tADL_min, period);
+	reg = TIMING_TADL(OFFSET(val, 3));
+
+	writel_relaxed(reg, ctrl->regs + TIMING_2);
+}
+
+static int tegra_nand_setup_data_interface(struct mtd_info *mtd, int csline,
+					const struct nand_data_interface *conf)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
+	const struct nand_sdr_timings *timings;
+
+	timings = nand_get_sdr_timings(conf);
+	if (IS_ERR(timings))
+		return PTR_ERR(timings);
+
+	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
+		return 0;
+
+	tegra_nand_setup_timing(ctrl, timings);
+
+	return 0;
+}
+
+static const int rs_strength_bootable[] = { 4 };
+static const int rs_strength[] = { 4, 6, 8 };
+static const int bch_strength_bootable[] = { 8, 16 };
+static const int bch_strength[] = { 4, 8, 14, 16 };
+
+static int tegra_nand_get_strength(struct nand_chip *chip, const int *strength,
+				   int strength_len, int bits_per_step,
+				   int oobsize)
+{
+	bool maximize = chip->ecc.options & NAND_ECC_MAXIMIZE;
+	int i;
+
+	/*
+	 * Loop through available strengths. Backwards in case we try to
+	 * maximize the BCH strength.
+	 */
+	for (i = 0; i < strength_len; i++) {
+		int strength_sel, bytes_per_step, bytes_per_page;
+
+		if (maximize) {
+			strength_sel = strength[strength_len - i - 1];
+		} else {
+			strength_sel = strength[i];
+
+			if (strength_sel < chip->ecc_strength_ds)
+				continue;
+		}
+
+		bytes_per_step = DIV_ROUND_UP(bits_per_step * strength_sel,
+					      BITS_PER_BYTE);
+		bytes_per_page = round_up(bytes_per_step * chip->ecc.steps, 4);
+
+		/* Check whether strength fits OOB */
+		if (bytes_per_page < (oobsize - SKIP_SPARE_BYTES))
+			return strength_sel;
+	}
+
+	return -EINVAL;
+}
+
+static int tegra_nand_select_strength(struct nand_chip *chip, int oobsize)
+{
+	const int *strength;
+	int strength_len, bits_per_step;
+
+	switch (chip->ecc.algo) {
+	case NAND_ECC_RS:
+		bits_per_step = BITS_PER_STEP_RS;
+		if (chip->options & NAND_IS_BOOT_MEDIUM) {
+			strength = rs_strength_bootable;
+			strength_len = ARRAY_SIZE(rs_strength_bootable);
+		} else {
+			strength = rs_strength;
+			strength_len = ARRAY_SIZE(rs_strength);
+		}
+		break;
+	case NAND_ECC_BCH:
+		bits_per_step = BITS_PER_STEP_BCH;
+		if (chip->options & NAND_IS_BOOT_MEDIUM) {
+			strength = bch_strength_bootable;
+			strength_len = ARRAY_SIZE(bch_strength_bootable);
+		} else {
+			strength = bch_strength;
+			strength_len = ARRAY_SIZE(bch_strength);
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return tegra_nand_get_strength(chip, strength, strength_len,
+				       bits_per_step, oobsize);
+}
+
+static int tegra_nand_chips_init(struct device *dev,
+				 struct tegra_nand_controller *ctrl)
+{
+	struct device_node *np = dev->of_node;
+	struct device_node *np_nand;
+	int nsels, nchips = of_get_child_count(np);
+	struct tegra_nand_chip *nand;
+	struct mtd_info *mtd;
+	struct nand_chip *chip;
+	int bits_per_step;
+	int ret;
+	u32 cs;
+
+	if (nchips != 1) {
+		dev_err(dev, "Currently only one NAND chip supported\n");
+		return -EINVAL;
+	}
+
+	np_nand = of_get_next_child(np, NULL);
+
+	nsels = of_property_count_elems_of_size(np_nand, "reg", sizeof(u32));
+	if (nsels != 1) {
+		dev_err(dev, "Missing/invalid reg property\n");
+		return -EINVAL;
+	}
+
+	/* Retrieve CS id, currently only single die NAND supported */
+	ret = of_property_read_u32(np_nand, "reg", &cs);
+	if (ret) {
+		dev_err(dev, "could not retrieve reg property: %d\n", ret);
+		return ret;
+	}
+
+	nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
+	if (!nand)
+		return -ENOMEM;
+
+	nand->cs[0] = cs;
+
+	nand->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_LOW);
+
+	if (IS_ERR(nand->wp_gpio)) {
+		ret = PTR_ERR(nand->wp_gpio);
+		dev_err(dev, "Failed to request WP GPIO: %d\n", ret);
+		return ret;
+	}
+
+	chip = &nand->chip;
+	chip->controller = &ctrl->controller;
+
+	mtd = nand_to_mtd(chip);
+
+	mtd->dev.parent = dev;
+	mtd->owner = THIS_MODULE;
+
+	nand_set_flash_node(chip, np_nand);
+
+	if (!mtd->name)
+		mtd->name = "tegra_nand";
+
+	chip->options = NAND_NO_SUBPAGE_WRITE | NAND_USE_BOUNCE_BUFFER;
+	chip->exec_op = tegra_nand_exec_op;
+	chip->select_chip = tegra_nand_select_chip;
+	chip->setup_data_interface = tegra_nand_setup_data_interface;
+
+	ret = nand_scan_ident(mtd, 1, NULL);
+	if (ret)
+		return ret;
+
+	if (chip->bbt_options & NAND_BBT_USE_FLASH)
+		chip->bbt_options |= NAND_BBT_NO_OOB;
+
+	chip->ecc.mode = NAND_ECC_HW;
+	chip->ecc.size = 512;
+	chip->ecc.steps = mtd->writesize / chip->ecc.size;
+	if (chip->ecc_step_ds != 512) {
+		dev_err(dev, "Unsupported step size %d\n", chip->ecc_step_ds);
+		return -EINVAL;
+	}
+
+	chip->ecc.read_page = tegra_nand_read_page_hwecc;
+	chip->ecc.write_page = tegra_nand_write_page_hwecc;
+	chip->ecc.read_page_raw = tegra_nand_read_page_raw;
+	chip->ecc.write_page_raw = tegra_nand_write_page_raw;
+	chip->ecc.read_oob = tegra_nand_read_oob;
+	chip->ecc.write_oob = tegra_nand_write_oob;
+
+	if (chip->options & NAND_BUSWIDTH_16)
+		nand->config |= CONFIG_BUS_WIDTH_16;
+
+	if (chip->ecc.algo == NAND_ECC_UNKNOWN) {
+		if (mtd->writesize < 2048)
+			chip->ecc.algo = NAND_ECC_RS;
+		else
+			chip->ecc.algo = NAND_ECC_BCH;
+	}
+
+	if (chip->ecc.algo == NAND_ECC_BCH && mtd->writesize < 2048) {
+		dev_err(dev, "BCH supportes 2K or 4K page size only\n");
+		return -EINVAL;
+	}
+
+	if (!chip->ecc.strength) {
+		ret = tegra_nand_select_strength(chip, mtd->oobsize);
+		if (ret < 0) {
+			dev_err(dev, "No valid strenght found, minimum %d\n",
+				chip->ecc_strength_ds);
+			return ret;
+		}
+
+		chip->ecc.strength = ret;
+	}
+
+	nand->config_ecc = CONFIG_PIPE_EN | CONFIG_SKIP_SPARE |
+			   CONFIG_SKIP_SPARE_SIZE_4;
+
+	switch (chip->ecc.algo) {
+	case NAND_ECC_RS:
+		bits_per_step = BITS_PER_STEP_RS * chip->ecc.strength;
+		mtd_set_ooblayout(mtd, &tegra_nand_oob_rs_ops);
+		nand->config_ecc |= CONFIG_HW_ECC | CONFIG_ECC_SEL |
+				    CONFIG_ERR_COR;
+		switch (chip->ecc.strength) {
+		case 4:
+			nand->config_ecc |= CONFIG_TVAL_4;
+			break;
+		case 6:
+			nand->config_ecc |= CONFIG_TVAL_6;
+			break;
+		case 8:
+			nand->config_ecc |= CONFIG_TVAL_8;
+			break;
+		default:
+			dev_err(dev, "ECC strength %d not supported\n",
+				chip->ecc.strength);
+			return -EINVAL;
+		}
+		break;
+	case NAND_ECC_BCH:
+		bits_per_step = BITS_PER_STEP_BCH * chip->ecc.strength;
+		mtd_set_ooblayout(mtd, &tegra_nand_oob_bch_ops);
+		nand->bch_config = BCH_ENABLE;
+		switch (chip->ecc.strength) {
+		case 4:
+			nand->bch_config |= BCH_TVAL_4;
+			break;
+		case 8:
+			nand->bch_config |= BCH_TVAL_8;
+			break;
+		case 14:
+			nand->bch_config |= BCH_TVAL_14;
+			break;
+		case 16:
+			nand->bch_config |= BCH_TVAL_16;
+			break;
+		default:
+			dev_err(dev, "ECC strength %d not supported\n",
+				chip->ecc.strength);
+			return -EINVAL;
+		}
+		break;
+	default:
+		dev_err(dev, "ECC algorithm not supported\n");
+		return -EINVAL;
+	}
+
+	dev_info(dev, "Using %s with strength %d per 512 byte step\n",
+			chip->ecc.algo == NAND_ECC_BCH ? "BCH" : "RS",
+			chip->ecc.strength);
+
+	chip->ecc.bytes = DIV_ROUND_UP(bits_per_step, BITS_PER_BYTE);
+
+	switch (mtd->writesize) {
+	case 256:
+		nand->config |= CONFIG_PS_256;
+		break;
+	case 512:
+		nand->config |= CONFIG_PS_512;
+		break;
+	case 1024:
+		nand->config |= CONFIG_PS_1024;
+		break;
+	case 2048:
+		nand->config |= CONFIG_PS_2048;
+		break;
+	case 4096:
+		nand->config |= CONFIG_PS_4096;
+		break;
+	default:
+		dev_err(dev, "Unsupported writesize %d\n", mtd->writesize);
+		return -ENODEV;
+	}
+
+	/* Store complete configuration for HW ECC in config_ecc */
+	nand->config_ecc |= nand->config;
+
+	/* Non-HW ECC read/writes complete OOB */
+	nand->config |= CONFIG_TAG_BYTE_SIZE(mtd->oobsize - 1);
+	writel_relaxed(nand->config, ctrl->regs + CONFIG);
+
+	ret = nand_scan_tail(mtd);
+	if (ret)
+		return ret;
+
+	mtd_ooblayout_ecc(mtd, 0, &nand->ecc);
+
+	ret = mtd_device_register(mtd, NULL, 0);
+	if (ret) {
+		dev_err(dev, "Failed to register mtd device: %d\n", ret);
+		nand_cleanup(chip);
+		return ret;
+	}
+
+	ctrl->chip = chip;
+
+	return 0;
+}
+
+static int tegra_nand_probe(struct platform_device *pdev)
+{
+	struct reset_control *rst;
+	struct tegra_nand_controller *ctrl;
+	struct resource *res;
+	int err = 0;
+
+	ctrl = devm_kzalloc(&pdev->dev, sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		return -ENOMEM;
+
+	ctrl->dev = &pdev->dev;
+	nand_hw_control_init(&ctrl->controller);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ctrl->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ctrl->regs))
+		return PTR_ERR(ctrl->regs);
+
+	rst = devm_reset_control_get(&pdev->dev, "nand");
+	if (IS_ERR(rst))
+		return PTR_ERR(rst);
+
+	ctrl->clk = devm_clk_get(&pdev->dev, "nand");
+	if (IS_ERR(ctrl->clk))
+		return PTR_ERR(ctrl->clk);
+
+	err = clk_prepare_enable(ctrl->clk);
+	if (err)
+		return err;
+
+	err = reset_control_reset(rst);
+	if (err) {
+		dev_err(ctrl->dev, "Failed to reset HW: %d\n", err);
+		goto err_disable_clk;
+	}
+
+	writel_relaxed(HWSTATUS_CMD_DEFAULT, ctrl->regs + HWSTATUS_CMD);
+	writel_relaxed(HWSTATUS_MASK_DEFAULT, ctrl->regs + HWSTATUS_MASK);
+	writel_relaxed(INT_MASK, ctrl->regs + IER);
+
+	init_completion(&ctrl->command_complete);
+	init_completion(&ctrl->dma_complete);
+
+	ctrl->irq = platform_get_irq(pdev, 0);
+	err = devm_request_irq(&pdev->dev, ctrl->irq, tegra_nand_irq, 0,
+			       dev_name(&pdev->dev), ctrl);
+	if (err) {
+		dev_err(ctrl->dev, "Failed to get IRQ: %d\n", err);
+		goto err_disable_clk;
+	}
+
+	writel_relaxed(DMA_MST_CTRL_IS_DONE, ctrl->regs + DMA_MST_CTRL);
+
+	err = tegra_nand_chips_init(ctrl->dev, ctrl);
+	if (err)
+		goto err_disable_clk;
+
+	platform_set_drvdata(pdev, ctrl);
+
+	return 0;
+
+err_disable_clk:
+	clk_disable_unprepare(ctrl->clk);
+	return err;
+}
+
+static int tegra_nand_remove(struct platform_device *pdev)
+{
+	struct tegra_nand_controller *ctrl = platform_get_drvdata(pdev);
+
+	nand_release(nand_to_mtd(ctrl->chip));
+
+	clk_disable_unprepare(ctrl->clk);
+
+	return 0;
+}
+
+static const struct of_device_id tegra_nand_of_match[] = {
+	{ .compatible = "nvidia,tegra20-nand" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, tegra_nand_of_match);
+
+static struct platform_driver tegra_nand_driver = {
+	.driver = {
+		.name = "tegra-nand",
+		.of_match_table = tegra_nand_of_match,
+	},
+	.probe = tegra_nand_probe,
+	.remove = tegra_nand_remove,
+};
+module_platform_driver(tegra_nand_driver);
+
+MODULE_DESCRIPTION("NVIDIA Tegra NAND driver");
+MODULE_AUTHOR("Thierry Reding <thierry.reding@nvidia.com>");
+MODULE_AUTHOR("Lucas Stach <dev@lynxeye.de>");
+MODULE_AUTHOR("Stefan Agner <stefan@agner.ch>");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1

[PATCH v6 5/6] ARM: dts: tegra: add Tegra20 NAND flash controller node

[Stefan Agner]

From: Lucas Stach <dev@lynxeye.de>

Add basic controller device tree node to be extended by
individual boards. Use the assigned-clocks mechanism to set
NDFLASH clock to a sensible default rate of 150MHz.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Stefan Agner <stefan@agner.ch>
---
 arch/arm/boot/dts/tegra20.dtsi | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi
index 983dd5c147945..a75fe7fec7912 100644
--- a/arch/arm/boot/dts/tegra20.dtsi
+++ b/arch/arm/boot/dts/tegra20.dtsi
@@ -425,6 +425,21 @@
 		status = "disabled";
 	};
 
+	nand-controller@70008000 {
+		compatible = "nvidia,tegra20-nand";
+		reg = <0x70008000 0x100>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		interrupts = <GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&tegra_car TEGRA20_CLK_NDFLASH>;
+		clock-names = "nand";
+		resets = <&tegra_car 13>;
+		reset-names = "nand";
+		assigned-clocks = <&tegra_car TEGRA20_CLK_NDFLASH>;
+		assigned-clock-rates = <150000000>;
+		status = "disabled";
+	};
+
 	pwm: pwm@7000a000 {
 		compatible = "nvidia,tegra20-pwm";
 		reg = <0x7000a000 0x100>;
-- 
2.17.1

[PATCH v6 6/6] ARM: dts: tegra: enable NAND flash on Colibri T20

[Stefan Agner]

This enables the on-module ONFI conformant NAND flash.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Stefan Agner <stefan@agner.ch>
---
 arch/arm/boot/dts/tegra20-colibri-512.dtsi | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/arm/boot/dts/tegra20-colibri-512.dtsi b/arch/arm/boot/dts/tegra20-colibri-512.dtsi
index 5c202b3e3bb1d..0c283fb772148 100644
--- a/arch/arm/boot/dts/tegra20-colibri-512.dtsi
+++ b/arch/arm/boot/dts/tegra20-colibri-512.dtsi
@@ -462,6 +462,22 @@
 		};
 	};
 
+	nand-controller@70008000 {
+		status = "okay";
+
+		nand@0 {
+			reg = <0>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			nand-bus-width = <8>;
+			nand-on-flash-bbt;
+			nand-ecc-algo = "bch";
+			nand-is-boot-medium;
+			nand-ecc-maximize;
+			wp-gpios = <&gpio TEGRA_GPIO(S, 0) GPIO_ACTIVE_LOW>;
+		};
+	};
+
 	usb@c5004000 {
 		status = "okay";
 		nvidia,phy-reset-gpio = <&gpio TEGRA_GPIO(V, 1)
-- 
2.17.1

Re: [PATCH v6 4/6] mtd: rawnand: add NVIDIA Tegra NAND Flash controller driver

[Boris Brezillon]

Hi Stefan,

On Thu, 21 Jun 2018 22:31:43 +0200
Stefan Agner <stefan@agner.ch> wrote:

> Add support for the NAND flash controller found on NVIDIA
> Tegra 2 SoCs. This implementation does not make use of the
> command queue feature. Regular operations using ->exec_op()
> use PIO mode for data transfers. Raw, ECC and OOB read/writes
> make use of the DMA mode for data transfer.
> 
> Signed-off-by: Lucas Stach <dev@lynxeye.de>
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  MAINTAINERS                       |    7 +
>  drivers/mtd/nand/raw/Kconfig      |    6 +
>  drivers/mtd/nand/raw/Makefile     |    1 +
>  drivers/mtd/nand/raw/tegra_nand.c | 1225 +++++++++++++++++++++++++++++
>  4 files changed, 1239 insertions(+)
>  create mode 100644 drivers/mtd/nand/raw/tegra_nand.c

I think we're almost good. No big issues spotted in this version.
Can you fix the CHECKs/WARNINGs reported by checkpatch --strict (most
of them are valid)?

> +
> +static int tegra_nand_remove(struct platform_device *pdev)
> +{
> +	struct tegra_nand_controller *ctrl = platform_get_drvdata(pdev);
> +
> +	nand_release(nand_to_mtd(ctrl->chip));

Use mtd_device_unregister() + nand_cleanup() instead of nand_release().
nand_release() is broken in that it does not check the return code of
mtd_device_unregister() before calling nand_cleanup(), and does not
propagate mtd_device_unregister() ret code to its caller. 

> +
> +	clk_disable_unprepare(ctrl->clk);
> +
> +	return 0;
> +}

Thanks for the great work you've done! Yay, another driver implementing
->exec_op()!

Boris