[v4,2/2] mtd: mediatek: driver for MTK Smart Device Gen1 NAND

Message ID 1461946642-1842-3-git-send-email-jorge.ramirez-ortiz@linaro.org
State New
Headers show

Commit Message

Jorge Ramirez April 29, 2016, 4:17 p.m.
This patch adds support for mediatek's SDG1 NFC nand controller
embedded in SoC 2701

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>

---
 drivers/mtd/nand/Kconfig    |    7 +
 drivers/mtd/nand/Makefile   |    1 +
 drivers/mtd/nand/mtk_ecc.c  |  527 ++++++++++++++++
 drivers/mtd/nand/mtk_ecc.h  |   53 ++
 drivers/mtd/nand/mtk_nand.c | 1432 +++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 2020 insertions(+)
 create mode 100644 drivers/mtd/nand/mtk_ecc.c
 create mode 100644 drivers/mtd/nand/mtk_ecc.h
 create mode 100644 drivers/mtd/nand/mtk_nand.c

-- 
2.7.4


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Comments

Jorge Ramirez May 2, 2016, 11:38 a.m. | #1
On 05/02/2016 02:13 AM, John Crispin wrote:
> Hi,

>

>> Your ecc-strength setting is wrong, because your nand device's OOB size

>> is not enough to store 24 bit ecc parity data.

>> For this nand, its ecc-strength is max 12 bit per 1024B for our

>> controller.

>> You can get the setting as mtk-nand DT Documentation description.

> i tried 12 aswell and it also gives an error. the problem with the

> documentation is that FDM is unknown to me.

>

>

>> Because the ecc-size and ecc-strength settings are optional, so if you

>> are not sure how to set them, you can remove the setting from DT file.

> tried that just now, the driver defaults to 12 and problem remains


can you send the boot log letting the driver use its own calculated values?
ie, just don't specify any of the controller optional values in the 
device tree and let the driver calculate them for you.

Also instead of a read operation, can you try the oobtest?
you will have to insmod or modprobe "mtd_oobtest dev="

I don't have the spec for the MT7623 but maybe also worth checking the 
configuration for the NFI_ACCON settings (timing control register).




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Jorge Ramirez May 10, 2016, 2:37 p.m. | #2
On 05/10/2016 08:13 AM, Boris Brezillon wrote:
>> +#define ECC_IDLE_REG(x)		((x) == ECC_ENC ? ECC_ENCIDLE : ECC_DECIDLE)

>> >+#define ECC_IDLE_MASK(x)	((x) == ECC_ENC ? ENC_IDLE : DEC_IDLE)

> No need for this macro, it's always bit0, so just define an ECC_IDLE

> macro and use it for both decoder and encoder.


this was only done for consistency to help people reading the code (same 
for codec_enable, codec_disable).
I suppose I could remove macros and just write 0 and 1 to the registers 
if you prefer that.

>

> There seems to be some kind of pattern in your ENC/DEC registers.

> ENC registers start at 0 and DEC ones at 0x100.

> CNF register is always at 0x4 + mode/dir_offset (ie 0x100 for DEC and

> 0x0 for ENC), ...

> Maybe you should define common macros for those registers, and choose

> the base offset depending on the mode you're operating in (encoding or

> decoding).


Not sure if you are familiar with George Lakoff and his book "Don't 
Think Of An Elephant! Know Your Values And Frame The Debate" but the key 
message is not to engage in a discussion when you disagree with the 
terms used by your counterpart since you wont be able to frame the 
argument (the book is actually very interesting if politics and and the 
political debate is something that interest you)

I explicitly chose not to talk about modes, instead I chose the engine 
driver to talk about the codecs it controls; for me mode is a higher 
level concept that I didn't have a need for since in this case the mode 
is a 1-1 relationship to the codec. So when you tell me about the mode 
the engine is operating in I'd rather say the codec that the ecc engine 
is accessing. I hope it makes sense.

if you want to talk about modes instead of the encoders and decoders 
that is fine since you are the maintainer.
I can rewrite the relevant parts of the driver but I honestly see no value.

why did I wrote these macros? just for readability since they are simple 
conditionals.
So coming back to your second question, I not sure why I would use a 
base offset when I already have the map. I wouldn't.

>

>> >+#define ECC_IRQ_REG(x)		((x) == ECC_ENC ? ECC_ENCIRQ_EN : ECC_DECIRQ_EN)

>> >+#define ECC_IRQ_EN(x)		((x) == ECC_ENC ? ENC_IRQEN : DEC_IRQEN)

>> >+#define ECC_CTL_REG(x)		((x) == ECC_ENC ? ECC_ENCCON : ECC_DECCON)

>> >+#define ECC_CODEC_ENABLE(x)	((x) == ECC_ENC ? ENC_EN : DEC_EN)

>> >+#define ECC_CODEC_DISABLE(x)	((x) == ECC_ENC ? ENC_DE : DEC_DE)




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Jorge Ramirez May 10, 2016, 2:45 p.m. | #3
On 05/10/2016 08:13 AM, Boris Brezillon wrote:
>> +struct mtk_ecc {

>> >+	struct device *dev;

>> >+	void __iomem *regs;

>> >+	struct clk *clk;

>> >+

>> >+	struct completion done;

>> >+	struct semaphore sem;

> You tried to explain me why you decided to go for a semaphore instead of

> a mutex, but I don't remember. Could you explain it again?

> If that's all about being interruptible, then you can use


Just for flexibility, no other reason really.
Neither the mutex nor the semaphore are actually needed in this driver.
Not knowing how things are going to evolve in the upper layers of MTD I 
didn't feel comfortable taking a lock in a function and unlocking the 
mutex in a different function (which is the way this driver operates). 
with that in mind I opted for a semaphore since it can always be 
unlocked -if needed be- by a different thread.




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Jorge Ramirez May 10, 2016, 2:50 p.m. | #4
On 05/10/2016 08:13 AM, Boris Brezillon wrote:
>> +	if (config->codec == ECC_ENC) {

>> >+		/* configure ECC encoder (in bits) */

>> >+		enc_sz = config->enc_len << 3;

>> >+

>> >+		reg = ecc_bit | (config->ecc_mode << ECC_MODE_SHIFT);

>> >+		reg |= (enc_sz << ECC_MS_SHIFT);

>> >+		writel(reg, ecc->regs + ECC_ENCCNFG);

>> >+

>> >+		if (config->ecc_mode != ECC_NFI_MODE)

>> >+			writel(lower_32_bits(config->addr),

>> >+				ecc->regs + ECC_ENCDIADDR);

>> >+

>> >+	} else {

>> >+		/* configure ECC decoder (in bits) */

>> >+		dec_sz = config->dec_len;

>> >+

>> >+		reg = ecc_bit | (config->ecc_mode << ECC_MODE_SHIFT);

>> >+		reg |= (dec_sz << ECC_MS_SHIFT) | DEC_CNFG_CORRECT;

>> >+		reg |= DEC_EMPTY_EN;

>> >+		writel(reg, ecc->regs + ECC_DECCNFG);

>> >+

>> >+		if (config->sec_mask)

>> >+			ecc->sec_mask = 1 << (config->sec_mask - 1);

>> >+	}

> I see that some of the logic could be shared between the ENC and DEC

> cases.


I guess you are referring to
reg = ecc_bit | (config->ecc_mode << ECC_MODE_SHIFT);

ok...

> BTW, why do you multiply enc_len by 8 (bits to byte conversion), but

> don't do that for dec_len?

>


just as needed by the hardware:
the config is in bits, the encoder register requires bytes, the decoder 
register requires bits.


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Jorge Ramirez May 10, 2016, 2:53 p.m. | #5
On 05/10/2016 08:13 AM, Boris Brezillon wrote:
>> +

>> >+void mtk_ecc_disable(struct mtk_ecc *ecc, struct mtk_ecc_config *config)

> If you save the mode somewhere in mtk_ecc (or just write in both ENC

> and DEC registers), you won't need this extra config arg here.


ok.

>

>> >+{

>> >+	enum mtk_ecc_codec codec = config->codec;

>> >+

>> >+	mtk_ecc_codec_wait_idle(ecc, codec);

>> >+	writew(0, ecc->regs + ECC_IRQ_REG(codec));

>> >+	writew(ECC_CODEC_DISABLE(codec), ecc->regs + ECC_CTL_REG(codec));

>> >+	up(&ecc->sem);

>> >+}

>> >+EXPORT_SYMBOL(mtk_ecc_disable);



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Jorge Ramirez May 10, 2016, 2:53 p.m. | #6
On 05/10/2016 08:13 AM, Boris Brezillon wrote:
>> +

>> >+void mtk_ecc_hw_init(struct mtk_ecc *ecc)

> No need to expose this function. Make it static and remove the

> prototype in your header.

>

yes, it was a leftover.

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Jorge Ramirez May 10, 2016, 3:18 p.m. | #7
On 05/10/2016 10:59 AM, Boris Brezillon wrote:
> On Tue, 10 May 2016 10:45:31 -0400

> Jorge Ramirez<jorge.ramirez-ortiz@linaro.org>  wrote:

>

>> >On 05/10/2016 08:13 AM, Boris Brezillon wrote:

>>>> > >>+struct mtk_ecc {

>>>>> > >> >+	struct device *dev;

>>>>> > >> >+	void __iomem *regs;

>>>>> > >> >+	struct clk *clk;

>>>>> > >> >+

>>>>> > >> >+	struct completion done;

>>>>> > >> >+	struct semaphore sem;

>>> > >You tried to explain me why you decided to go for a semaphore instead of

>>> > >a mutex, but I don't remember. Could you explain it again?

>>> > >If that's all about being interruptible, then you can use

>> >

>> >Just for flexibility, no other reason really.

>> >Neither the mutex nor the semaphore are actually needed in this driver.

>> >Not knowing how things are going to evolve in the upper layers of MTD I

>> >didn't feel comfortable taking a lock in a function and unlocking the

>> >mutex in a different function (which is the way this driver operates).

>> >with that in mind I opted for a semaphore since it can always be

>> >unlocked -if needed be- by a different thread.

> But that has nothing to do with possible evolutions in the MTD layer.

> The ECC engine resource can only have a single user at a time, hence

> the mutex approach. Sorry, but I don't understand the "flexibility"

> argument, but maybe I'm misunderstanding the different between a

> semaphore and a mutex.


mutex can only be unlocked by the same thread that locks it. if for some 
reason (hypotetically speaking) the MTD wishes to unlock ecc engines and 
implement an abort operation before running operations complete this 
could guarantee that the ecc engine is left in an unlocked state. the 
risk of having a mutex in this driver is that the lock/unlock happen in 
_different_ function calls (which is always scary) with DMAs having to 
complete in between so if the running thread was canceled before the 
mutex protecting the resource was unlocked we would never be able to 
unlock it....with a semaphore we could (any thread could unlock the 
resource).






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Jorge Ramirez May 10, 2016, 3:37 p.m. | #8
On 05/10/2016 11:13 AM, Boris Brezillon wrote:
>> >just as needed by the hardware:

>> >the config is in bits, the encoder register requires bytes, the decoder

>> >register requires bits.

>> >

> Are you sure about that? Cause it seems to me that the NAND controller

> drivers put a length in bits in ->dec_len and a length in bytes in

> ->enc_len, and then you have an extra conversion in the ECC engine

> driver code for enc_len to convert it into a value in bits.


yes you are right (was reading at the spec before to be sure but the 
spec is wrong since the driver works...yes I remember now discussing 
this with mediatek).
"ENC_MS: indicates the total bytes size of message block. the message 
block can only be in byte unit." - yes, this line of the spec is wrong.

will fix the code to make it consistent on the config interface (both 
enc_len or dec_len should be the same unit); and in fact as you also 
pointed out we only need one len parameter since the decoder len can be 
deduced from the encoder using the strength and the number of parity bits.

thanks!





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Jorge Ramirez May 10, 2016, 6:14 p.m. | #9
On 05/10/2016 10:53 AM, Jorge Ramirez wrote:
> On 05/10/2016 08:13 AM, Boris Brezillon wrote:

>>> +

>>> >+void mtk_ecc_disable(struct mtk_ecc *ecc, struct mtk_ecc_config 

>>> *config)

>> If you save the mode somewhere in mtk_ecc (or just write in both ENC

>> and DEC registers), you won't need this extra config arg here.

>

> ok. 


actually as I was implementing this change (and it is a simple change to 
do) I am not sure that it is a good idea to store the state of the 
engine in the ecc_driver (ie: codec_x active sort of flag). And writing 
to both set of registers looks ugly to me.

the way the nand driver is written, it is the nand driver the one that 
controls the ecc engine 'states' (init, enable_x,disable_x). Why do we 
want the ecc engine to remember that it was running the encoder or the 
decoder? I think keeping the parameter in this function makes more 
sense, that way the ecc driver itself completely stateless.

however let me see if there is a register I can poke to find out the 
active codec (then I could remove the config parameter that you pointed 
out without having to store state). I should be able to just read the 
ECC control register to determine this.



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Patch

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index f05e0e9..3c26e89 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -563,4 +563,11 @@  config MTD_NAND_QCOM
 	  Enables support for NAND flash chips on SoCs containing the EBI2 NAND
 	  controller. This controller is found on IPQ806x SoC.
 
+config MTD_NAND_MTK
+	tristate "Support for NAND controller on MTK SoCs"
+	depends on HAS_DMA
+	help
+	  Enables support for NAND controller on MTK SoCs.
+	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
+
 endif # MTD_NAND
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index f553353..cafde6f 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -57,5 +57,6 @@  obj-$(CONFIG_MTD_NAND_SUNXI)		+= sunxi_nand.o
 obj-$(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_nand.o mtk_ecc.o
 
 nand-objs := nand_base.o nand_bbt.o nand_timings.o
diff --git a/drivers/mtd/nand/mtk_ecc.c b/drivers/mtd/nand/mtk_ecc.c
new file mode 100644
index 0000000..28769f1
--- /dev/null
+++ b/drivers/mtd/nand/mtk_ecc.c
@@ -0,0 +1,527 @@ 
+/*
+ * MTK ECC controller driver.
+ * Copyright (C) 2016  MediaTek Inc.
+ * Authors:	Xiaolei Li		<xiaolei.li@mediatek.com>
+ *		Jorge Ramirez-Ortiz	<jorge.ramirez-ortiz@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/semaphore.h>
+
+#include "mtk_ecc.h"
+
+#define ECC_ENCCON		(0x00)
+#define		ENC_EN			(1)
+#define		ENC_DE			(0)
+#define ECC_ENCCNFG		(0x04)
+#define		ECC_CNFG_4BIT		(0)
+#define		ECC_CNFG_6BIT		(1)
+#define		ECC_CNFG_8BIT		(2)
+#define		ECC_CNFG_10BIT		(3)
+#define		ECC_CNFG_12BIT		(4)
+#define		ECC_CNFG_14BIT		(5)
+#define		ECC_CNFG_16BIT		(6)
+#define		ECC_CNFG_18BIT		(7)
+#define		ECC_CNFG_20BIT		(8)
+#define		ECC_CNFG_22BIT		(9)
+#define		ECC_CNFG_24BIT		(0xa)
+#define		ECC_CNFG_28BIT		(0xb)
+#define		ECC_CNFG_32BIT		(0xc)
+#define		ECC_CNFG_36BIT		(0xd)
+#define		ECC_CNFG_40BIT		(0xe)
+#define		ECC_CNFG_44BIT		(0xf)
+#define		ECC_CNFG_48BIT		(0x10)
+#define		ECC_CNFG_52BIT		(0x11)
+#define		ECC_CNFG_56BIT		(0x12)
+#define		ECC_CNFG_60BIT		(0x13)
+#define		ECC_MODE_SHIFT		(5)
+#define		ECC_MS_SHIFT		(16)
+#define ECC_ENCDIADDR		(0x08)
+#define ECC_ENCIDLE		(0x0C)
+#define		ENC_IDLE		BIT(0)
+#define ECC_ENCPAR(x)		(0x10 + (x) * sizeof(u32))
+#define ECC_ENCIRQ_EN		(0x80)
+#define		ENC_IRQEN		BIT(0)
+#define ECC_ENCIRQ_STA		(0x84)
+#define ECC_DECCON		(0x100)
+#define		DEC_EN			(1)
+#define		DEC_DE			(0)
+#define ECC_DECCNFG		(0x104)
+#define		DEC_EMPTY_EN		BIT(31)
+#define		DEC_CNFG_CORRECT	(0x3 << 12)
+#define ECC_DECIDLE		(0x10C)
+#define		DEC_IDLE		BIT(0)
+#define ECC_DECENUM0		(0x114)
+#define		ERR_MASK		(0x3f)
+#define ECC_DECDONE		(0x124)
+#define ECC_DECIRQ_EN		(0x200)
+#define		DEC_IRQEN		BIT(0)
+#define ECC_DECIRQ_STA		(0x204)
+
+#define ECC_TIMEOUT		(500000)
+
+#define ECC_IDLE_REG(x)		((x) == ECC_ENC ? ECC_ENCIDLE : ECC_DECIDLE)
+#define ECC_IDLE_MASK(x)	((x) == ECC_ENC ? ENC_IDLE : DEC_IDLE)
+#define ECC_IRQ_REG(x)		((x) == ECC_ENC ? ECC_ENCIRQ_EN : ECC_DECIRQ_EN)
+#define ECC_IRQ_EN(x)		((x) == ECC_ENC ? ENC_IRQEN : DEC_IRQEN)
+#define ECC_CTL_REG(x)		((x) == ECC_ENC ? ECC_ENCCON : ECC_DECCON)
+#define ECC_CODEC_ENABLE(x)	((x) == ECC_ENC ? ENC_EN : DEC_EN)
+#define ECC_CODEC_DISABLE(x)	((x) == ECC_ENC ? ENC_DE : DEC_DE)
+
+struct mtk_ecc {
+	struct device *dev;
+	void __iomem *regs;
+	struct clk *clk;
+
+	struct completion done;
+	struct semaphore sem;
+	u32 sec_mask;
+};
+
+static inline void mtk_ecc_codec_wait_idle(struct mtk_ecc *ecc,
+					enum mtk_ecc_codec codec)
+{
+	struct device *dev = ecc->dev;
+	u32 val;
+	int ret;
+
+	ret = readl_poll_timeout_atomic(ecc->regs + ECC_IDLE_REG(codec), val,
+					val & ECC_IDLE_MASK(codec),
+					10, ECC_TIMEOUT);
+	if (ret)
+		dev_warn(dev, "%s NOT idle\n",
+			codec == ECC_ENC ? "encoder" : "decoder");
+}
+
+static irqreturn_t mtk_ecc_irq(int irq, void *id)
+{
+	struct mtk_ecc *ecc = id;
+	enum mtk_ecc_codec codec;
+	u32 dec, enc;
+
+	dec = readw(ecc->regs + ECC_DECIRQ_STA) & DEC_IRQEN;
+	if (dec) {
+		codec = ECC_DEC;
+		dec = readw(ecc->regs + ECC_DECDONE);
+		if (dec & ecc->sec_mask) {
+			ecc->sec_mask = 0;
+			complete(&ecc->done);
+		} else
+			return IRQ_HANDLED;
+	} else {
+		enc = readl(ecc->regs + ECC_ENCIRQ_STA) & ENC_IRQEN;
+		if (enc) {
+			codec = ECC_ENC;
+			complete(&ecc->done);
+		} else
+			return IRQ_NONE;
+	}
+
+	writel(0, ecc->regs + ECC_IRQ_REG(codec));
+
+	return IRQ_HANDLED;
+}
+
+static void mtk_ecc_config(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
+{
+	u32 ecc_bit = ECC_CNFG_4BIT, dec_sz, enc_sz;
+	u32 reg;
+
+	switch (config->strength) {
+	case 4:
+		ecc_bit = ECC_CNFG_4BIT;
+		break;
+	case 6:
+		ecc_bit = ECC_CNFG_6BIT;
+		break;
+	case 8:
+		ecc_bit = ECC_CNFG_8BIT;
+		break;
+	case 10:
+		ecc_bit = ECC_CNFG_10BIT;
+		break;
+	case 12:
+		ecc_bit = ECC_CNFG_12BIT;
+		break;
+	case 14:
+		ecc_bit = ECC_CNFG_14BIT;
+		break;
+	case 16:
+		ecc_bit = ECC_CNFG_16BIT;
+		break;
+	case 18:
+		ecc_bit = ECC_CNFG_18BIT;
+		break;
+	case 20:
+		ecc_bit = ECC_CNFG_20BIT;
+		break;
+	case 22:
+		ecc_bit = ECC_CNFG_22BIT;
+		break;
+	case 24:
+		ecc_bit = ECC_CNFG_24BIT;
+		break;
+	case 28:
+		ecc_bit = ECC_CNFG_28BIT;
+		break;
+	case 32:
+		ecc_bit = ECC_CNFG_32BIT;
+		break;
+	case 36:
+		ecc_bit = ECC_CNFG_36BIT;
+		break;
+	case 40:
+		ecc_bit = ECC_CNFG_40BIT;
+		break;
+	case 44:
+		ecc_bit = ECC_CNFG_44BIT;
+		break;
+	case 48:
+		ecc_bit = ECC_CNFG_48BIT;
+		break;
+	case 52:
+		ecc_bit = ECC_CNFG_52BIT;
+		break;
+	case 56:
+		ecc_bit = ECC_CNFG_56BIT;
+		break;
+	case 60:
+		ecc_bit = ECC_CNFG_60BIT;
+		break;
+	default:
+		dev_err(ecc->dev, "invalid strength %d\n", config->strength);
+	}
+
+	if (config->codec == ECC_ENC) {
+		/* configure ECC encoder (in bits) */
+		enc_sz = config->enc_len << 3;
+
+		reg = ecc_bit | (config->ecc_mode << ECC_MODE_SHIFT);
+		reg |= (enc_sz << ECC_MS_SHIFT);
+		writel(reg, ecc->regs + ECC_ENCCNFG);
+
+		if (config->ecc_mode != ECC_NFI_MODE)
+			writel(lower_32_bits(config->addr),
+				ecc->regs + ECC_ENCDIADDR);
+
+	} else {
+		/* configure ECC decoder (in bits) */
+		dec_sz = config->dec_len;
+
+		reg = ecc_bit | (config->ecc_mode << ECC_MODE_SHIFT);
+		reg |= (dec_sz << ECC_MS_SHIFT) | DEC_CNFG_CORRECT;
+		reg |= DEC_EMPTY_EN;
+		writel(reg, ecc->regs + ECC_DECCNFG);
+
+		if (config->sec_mask)
+			ecc->sec_mask = 1 << (config->sec_mask - 1);
+	}
+}
+
+void mtk_ecc_get_stats(struct mtk_ecc *ecc, struct mtk_ecc_stats *stats,
+			int sectors)
+{
+	u32 offset, i, err;
+	u32 bitflips = 0;
+
+	stats->corrected = 0;
+	stats->failed = 0;
+
+	for (i = 0; i < sectors; i++) {
+		offset = (i >> 2) << 2;
+		err = readl(ecc->regs + ECC_DECENUM0 + offset);
+		err = err >> ((i % 4) * 8);
+		err &= ERR_MASK;
+		if (err == ERR_MASK) {
+			/* uncorrectable errors */
+			stats->failed++;
+			continue;
+		}
+
+		stats->corrected += err;
+		bitflips = max_t(u32, bitflips, err);
+	}
+
+	stats->bitflips = bitflips;
+}
+EXPORT_SYMBOL(mtk_ecc_get_stats);
+
+void mtk_ecc_release(struct mtk_ecc *ecc)
+{
+	clk_disable_unprepare(ecc->clk);
+	put_device(ecc->dev);
+}
+EXPORT_SYMBOL(mtk_ecc_release);
+
+static struct mtk_ecc *mtk_ecc_get(struct device_node *np)
+{
+	struct platform_device *pdev;
+	struct mtk_ecc *ecc;
+
+	pdev = of_find_device_by_node(np);
+	if (!pdev || !platform_get_drvdata(pdev))
+		return ERR_PTR(-EPROBE_DEFER);
+
+	get_device(&pdev->dev);
+	ecc = platform_get_drvdata(pdev);
+	clk_prepare_enable(ecc->clk);
+	mtk_ecc_hw_init(ecc);
+
+	return ecc;
+}
+
+struct mtk_ecc *of_mtk_ecc_get(struct device_node *of_node)
+{
+	struct mtk_ecc *ecc = NULL;
+	struct device_node *np;
+
+	np = of_parse_phandle(of_node, "ecc-engine", 0);
+	if (np) {
+		ecc = mtk_ecc_get(np);
+		of_node_put(np);
+	}
+
+	return ecc;
+}
+EXPORT_SYMBOL(of_mtk_ecc_get);
+
+int mtk_ecc_enable(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
+{
+	enum mtk_ecc_codec codec = config->codec;
+	int ret;
+
+	ret = down_interruptible(&ecc->sem);
+	if (ret) {
+		dev_err(ecc->dev, "interrupted when attempting to lock\n");
+		return ret;
+	}
+
+	mtk_ecc_codec_wait_idle(ecc, codec);
+	mtk_ecc_config(ecc, config);
+	writew(ECC_CODEC_ENABLE(codec), ecc->regs + ECC_CTL_REG(codec));
+
+	init_completion(&ecc->done);
+	writew(ECC_IRQ_EN(codec), ecc->regs + ECC_IRQ_REG(codec));
+
+	return 0;
+}
+EXPORT_SYMBOL(mtk_ecc_enable);
+
+void mtk_ecc_disable(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
+{
+	enum mtk_ecc_codec codec = config->codec;
+
+	mtk_ecc_codec_wait_idle(ecc, codec);
+	writew(0, ecc->regs + ECC_IRQ_REG(codec));
+	writew(ECC_CODEC_DISABLE(codec), ecc->regs + ECC_CTL_REG(codec));
+	up(&ecc->sem);
+}
+EXPORT_SYMBOL(mtk_ecc_disable);
+
+int mtk_ecc_wait_irq_done(struct mtk_ecc *ecc, enum mtk_ecc_codec codec)
+{
+	int ret;
+
+	ret = wait_for_completion_timeout(&ecc->done, msecs_to_jiffies(500));
+	if (!ret) {
+		dev_err(ecc->dev, "%s timeout - interrupt did not arrive)\n",
+				(codec == ECC_ENC) ? "encoder" : "decoder");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(mtk_ecc_wait_irq_done);
+
+int mtk_ecc_encode_non_nfi_mode(struct mtk_ecc *ecc,
+			struct mtk_ecc_config *config, u8 *data, u32 bytes)
+{
+	dma_addr_t addr;
+	u32 *p, len, i;
+	int ret = 0;
+
+	addr = dma_map_single(ecc->dev, data, bytes, DMA_TO_DEVICE);
+	ret = dma_mapping_error(ecc->dev, addr);
+	if (ret) {
+		dev_err(ecc->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	config->codec = ECC_ENC;
+	config->addr = addr;
+	ret = mtk_ecc_enable(ecc, config);
+	if (ret) {
+		dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
+		return ret;
+	}
+
+	ret = mtk_ecc_wait_irq_done(ecc, ECC_ENC);
+	if (ret)
+		goto timeout;
+
+	mtk_ecc_codec_wait_idle(ecc, ECC_ENC);
+
+	/* Program ECC bytes to OOB: per sector oob = FDM + ECC + SPARE */
+	len = (config->strength * ECC_PARITY_BITS + 7) >> 3;
+	p = (u32 *) (data + bytes);
+
+	/* write the parity bytes generated by the ECC back to the OOB region */
+	for (i = 0; i < len; i++)
+		p[i] = readl(ecc->regs + ECC_ENCPAR(i));
+timeout:
+
+	dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
+	mtk_ecc_disable(ecc, config);
+
+	return ret;
+}
+EXPORT_SYMBOL(mtk_ecc_encode_non_nfi_mode);
+
+void mtk_ecc_hw_init(struct mtk_ecc *ecc)
+{
+	mtk_ecc_codec_wait_idle(ecc, ECC_ENC);
+	writew(ENC_DE, ecc->regs + ECC_ENCCON);
+
+	mtk_ecc_codec_wait_idle(ecc, ECC_DEC);
+	writel(DEC_DE, ecc->regs + ECC_DECCON);
+}
+
+void mtk_ecc_update_strength(u32 *p)
+{
+	u32 ecc[] = {4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
+			40, 44, 48, 52, 56, 60};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ecc); i++) {
+		if (*p <= ecc[i]) {
+			if (!i)
+				*p = ecc[i];
+			else if (*p != ecc[i])
+				*p = ecc[i - 1];
+			return;
+		}
+	}
+
+	*p = ecc[ARRAY_SIZE(ecc) - 1];
+}
+EXPORT_SYMBOL(mtk_ecc_update_strength);
+
+static int mtk_ecc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_ecc *ecc;
+	struct resource *res;
+	int irq, ret;
+
+	ecc = devm_kzalloc(dev, sizeof(*ecc), GFP_KERNEL);
+	if (!ecc)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ecc->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(ecc->regs)) {
+		dev_err(dev, "failed to map regs: %ld\n", PTR_ERR(ecc->regs));
+		return PTR_ERR(ecc->regs);
+	}
+
+	ecc->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(ecc->clk)) {
+		dev_err(dev, "failed to get clock: %ld\n", PTR_ERR(ecc->clk));
+		return PTR_ERR(ecc->clk);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "failed to get irq\n");
+		return -EINVAL;
+	}
+
+	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dev, "failed to set DMA mask\n");
+		return ret;
+	}
+
+	ret = devm_request_irq(dev, irq, mtk_ecc_irq, 0x0, "mtk-ecc", ecc);
+	if (ret) {
+		dev_err(dev, "failed to request irq\n");
+		return -EINVAL;
+	}
+
+	ecc->dev = dev;
+	sema_init(&ecc->sem, 1);
+	platform_set_drvdata(pdev, ecc);
+	dev_info(dev, "probed\n");
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_ecc_suspend(struct device *dev)
+{
+	struct mtk_ecc *ecc = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(ecc->clk);
+
+	return 0;
+}
+
+static int mtk_ecc_resume(struct device *dev)
+{
+	struct mtk_ecc *ecc = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(ecc->clk);
+	if (ret) {
+		dev_err(dev, "failed to enable clk\n");
+		return ret;
+	}
+
+	mtk_ecc_hw_init(ecc);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(mtk_ecc_pm_ops, mtk_ecc_suspend, mtk_ecc_resume);
+#endif
+
+static const struct of_device_id mtk_ecc_dt_match[] = {
+	{ .compatible = "mediatek,mt2701-ecc" },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, mtk_ecc_dt_match);
+
+static struct platform_driver mtk_ecc_driver = {
+	.probe  = mtk_ecc_probe,
+	.driver = {
+		.name  = "mtk-ecc",
+		.of_match_table = of_match_ptr(mtk_ecc_dt_match),
+#ifdef CONFIG_PM_SLEEP
+		.pm = &mtk_ecc_pm_ops,
+#endif
+	},
+};
+
+module_platform_driver(mtk_ecc_driver);
+
+MODULE_AUTHOR("Xiaolei Li <xiaolei.li@mediatek.com>");
+MODULE_AUTHOR("Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>");
+MODULE_DESCRIPTION("MTK Nand ECC Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mtd/nand/mtk_ecc.h b/drivers/mtd/nand/mtk_ecc.h
new file mode 100644
index 0000000..434826f
--- /dev/null
+++ b/drivers/mtd/nand/mtk_ecc.h
@@ -0,0 +1,53 @@ 
+/*
+ * MTK SDG1 ECC controller
+ *
+ * Copyright (c) 2016 Mediatek
+ * Authors:	Xiaolei Li		<xiaolei.li@mediatek.com>
+ *		Jorge Ramirez-Ortiz	<jorge.ramirez-ortiz@linaro.org>
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#ifndef __DRIVERS_MTD_NAND_MTK_ECC_H__
+#define __DRIVERS_MTD_NAND_MTK_ECC_H__
+
+#include <linux/types.h>
+
+#define ECC_PARITY_BITS		(14)
+
+enum mtk_ecc_mode {ECC_DMA_MODE = 0, ECC_NFI_MODE = 1};
+enum mtk_ecc_codec {ECC_ENC, ECC_DEC};
+
+struct device_node;
+struct mtk_ecc;
+
+struct mtk_ecc_stats {
+	u32 corrected;
+	u32 bitflips;
+	u32 failed;
+};
+
+struct mtk_ecc_config {
+	enum mtk_ecc_mode ecc_mode;
+	enum mtk_ecc_codec codec;
+	dma_addr_t addr;
+	u32 sec_mask;
+	u32 strength;
+	u32 enc_len;
+	u32 dec_len;
+};
+
+int mtk_ecc_enable(struct mtk_ecc *, struct mtk_ecc_config *);
+void mtk_ecc_disable(struct mtk_ecc *, struct mtk_ecc_config *);
+int mtk_ecc_encode_non_nfi_mode(struct mtk_ecc *, struct mtk_ecc_config *,
+				u8 *, u32);
+void mtk_ecc_get_stats(struct mtk_ecc *, struct mtk_ecc_stats *, int);
+int mtk_ecc_wait_irq_done(struct mtk_ecc *, enum mtk_ecc_codec);
+void mtk_ecc_hw_init(struct mtk_ecc *);
+void mtk_ecc_update_strength(u32 *);
+
+struct mtk_ecc *of_mtk_ecc_get(struct device_node *);
+void mtk_ecc_release(struct mtk_ecc *);
+
+#endif
diff --git a/drivers/mtd/nand/mtk_nand.c b/drivers/mtd/nand/mtk_nand.c
new file mode 100644
index 0000000..907b90c
--- /dev/null
+++ b/drivers/mtd/nand/mtk_nand.c
@@ -0,0 +1,1432 @@ 
+/*
+ * MTK NAND Flash controller driver.
+ * Copyright (C) 2016 MediaTek Inc.
+ * Authors:	Xiaolei Li		<xiaolei.li@mediatek.com>
+ *		Jorge Ramirez-Ortiz	<jorge.ramirez-ortiz@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/mtd.h>
+#include <linux/module.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include "mtk_ecc.h"
+
+/* NAND controller register definition */
+#define NFI_CNFG		(0x00)
+#define		CNFG_AHB		BIT(0)
+#define		CNFG_READ_EN		BIT(1)
+#define		CNFG_DMA_BURST_EN	BIT(2)
+#define		CNFG_BYTE_RW		BIT(6)
+#define		CNFG_HW_ECC_EN		BIT(8)
+#define		CNFG_AUTO_FMT_EN	BIT(9)
+#define		CNFG_OP_CUST		(6 << 12)
+#define NFI_PAGEFMT		(0x04)
+#define		PAGEFMT_FDM_ECC_SHIFT	(12)
+#define		PAGEFMT_FDM_SHIFT	(8)
+#define		PAGEFMT_SPARE_16	(0)
+#define		PAGEFMT_SPARE_26	(1)
+#define		PAGEFMT_SPARE_27	(2)
+#define		PAGEFMT_SPARE_28	(3)
+#define		PAGEFMT_SPARE_32	(4)
+#define		PAGEFMT_SPARE_36	(5)
+#define		PAGEFMT_SPARE_40	(6)
+#define		PAGEFMT_SPARE_44	(7)
+#define		PAGEFMT_SPARE_48	(8)
+#define		PAGEFMT_SPARE_49	(9)
+#define		PAGEFMT_SPARE_50	(0xa)
+#define		PAGEFMT_SPARE_51	(0xb)
+#define		PAGEFMT_SPARE_52	(0xc)
+#define		PAGEFMT_SPARE_62	(0xd)
+#define		PAGEFMT_SPARE_63	(0xe)
+#define		PAGEFMT_SPARE_64	(0xf)
+#define		PAGEFMT_SPARE_SHIFT	(4)
+#define		PAGEFMT_SEC_SEL_512	BIT(2)
+#define		PAGEFMT_512_2K		(0)
+#define		PAGEFMT_2K_4K		(1)
+#define		PAGEFMT_4K_8K		(2)
+#define		PAGEFMT_8K_16K		(3)
+/* NFI control */
+#define NFI_CON			(0x08)
+#define		CON_FIFO_FLUSH		BIT(0)
+#define		CON_NFI_RST		BIT(1)
+#define		CON_BRD			BIT(8)  /* burst  read */
+#define		CON_BWR			BIT(9)	/* burst  write */
+#define		CON_SEC_SHIFT		(12)
+/* Timming control register */
+#define NFI_ACCCON		(0x0C)
+#define NFI_INTR_EN		(0x10)
+#define		INTR_AHB_DONE_EN	BIT(6)
+#define NFI_INTR_STA		(0x14)
+#define NFI_CMD			(0x20)
+#define NFI_ADDRNOB		(0x30)
+#define NFI_COLADDR		(0x34)
+#define NFI_ROWADDR		(0x38)
+#define NFI_STRDATA		(0x40)
+#define		STAR_EN			(1)
+#define		STAR_DE			(0)
+#define NFI_CNRNB		(0x44)
+#define NFI_DATAW		(0x50)
+#define NFI_DATAR		(0x54)
+#define NFI_PIO_DIRDY		(0x58)
+#define		PIO_DI_RDY		(0x01)
+#define NFI_STA			(0x60)
+#define		STA_CMD			BIT(0)
+#define		STA_ADDR		BIT(1)
+#define		STA_BUSY		BIT(8)
+#define		STA_EMP_PAGE		BIT(12)
+#define		NFI_FSM_CUSTDATA	(0xe << 16)
+#define		NFI_FSM_MASK		(0xf << 16)
+#define NFI_ADDRCNTR		(0x70)
+#define		CNTR_MASK		GENMASK(16, 12)
+#define NFI_STRADDR		(0x80)
+#define NFI_BYTELEN		(0x84)
+#define NFI_CSEL		(0x90)
+#define NFI_FDML(x)		(0xA0 + (x) * sizeof(u32) * 2)
+#define NFI_FDMM(x)		(0xA4 + (x) * sizeof(u32) * 2)
+#define NFI_FDM_MAX_SIZE	(8)
+#define NFI_MASTER_STA		(0x224)
+#define		MASTER_STA_MASK		(0x0FFF)
+#define NFI_EMPTY_THRESH	(0x23C)
+
+#define MTK_NAME		"mtk-nand"
+#define KB(x)			((x) * 1024UL)
+#define MB(x)			(KB(x) * 1024UL)
+
+#define MTK_TIMEOUT		(500000)
+#define MTK_RESET_TIMEOUT	(1000000)
+#define MTK_MAX_SECTOR		(16)
+#define MTK_NAND_MAX_NSELS	(2)
+
+typedef void (*bad_mark_swap)(struct mtd_info *, uint8_t *buf, int raw);
+struct mtk_nfc_bad_mark_ctl {
+	bad_mark_swap bm_swap;
+	u32 sec;
+	u32 pos;
+};
+
+/*
+ * FDM: region used to store free OOB data
+ */
+struct mtk_nfc_fdm {
+	u32 reg_size;
+	u32 ecc_size;
+};
+
+struct mtk_nfc_nand_chip {
+	struct list_head node;
+	struct nand_chip nand;
+
+	struct mtk_nfc_bad_mark_ctl bad_mark;
+	struct mtk_nfc_fdm fdm;
+	u32 spare_per_sector;
+
+	int nsels;
+	u8 sels[0];
+	/* nothing after this field */
+};
+
+struct mtk_nfc_clk {
+	struct clk *nfi_clk;
+	struct clk *pad_clk;
+};
+
+struct mtk_nfc {
+	struct nand_hw_control controller;
+	struct mtk_ecc_config ecc_cfg;
+	struct mtk_nfc_clk clk;
+	struct mtk_ecc *ecc;
+
+	struct device *dev;
+	void __iomem *regs;
+
+	struct completion done;
+	struct list_head chips;
+
+	u8 *buffer;
+};
+
+static inline struct mtk_nfc_nand_chip *to_mtk_nand(struct nand_chip *nand)
+{
+	return container_of(nand, struct mtk_nfc_nand_chip, nand);
+}
+
+static inline uint8_t *data_ptr(struct nand_chip *chip, const uint8_t *p, int i)
+{
+	return (uint8_t *) p + i * chip->ecc.size;
+}
+
+static inline uint8_t *oob_ptr(struct nand_chip *chip, int i)
+{
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	uint8_t *poi;
+
+	if (i < mtk_nand->bad_mark.sec)
+		poi = chip->oob_poi + (i + 1) * mtk_nand->fdm.reg_size;
+	else if (i == mtk_nand->bad_mark.sec)
+		poi = chip->oob_poi;
+	else
+		poi = chip->oob_poi + i * mtk_nand->fdm.reg_size;
+
+	return poi;
+}
+
+static inline int mtk_data_len(struct nand_chip *chip)
+{
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+
+	return chip->ecc.size + mtk_nand->spare_per_sector;
+}
+
+static inline uint8_t *mtk_data_ptr(struct nand_chip *chip,  int i)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+
+	return nfc->buffer + i * mtk_data_len(chip);
+}
+
+static inline uint8_t *mtk_oob_ptr(struct nand_chip *chip, int i)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+
+	return nfc->buffer + i * mtk_data_len(chip) + chip->ecc.size;
+}
+
+static inline void nfi_writel(struct mtk_nfc *nfc, u32 val, u32 reg)
+{
+	writel(val, nfc->regs + reg);
+}
+
+static inline void nfi_writew(struct mtk_nfc *nfc, u16 val, u32 reg)
+{
+	writew(val, nfc->regs + reg);
+}
+
+static inline void nfi_writeb(struct mtk_nfc *nfc, u8 val, u32 reg)
+{
+	writeb(val, nfc->regs + reg);
+}
+
+static inline u32 nfi_readl(struct mtk_nfc *nfc, u32 reg)
+{
+	return readl_relaxed(nfc->regs + reg);
+}
+
+static inline u16 nfi_readw(struct mtk_nfc *nfc, u32 reg)
+{
+	return readw_relaxed(nfc->regs + reg);
+}
+
+static inline u8 nfi_readb(struct mtk_nfc *nfc, u32 reg)
+{
+	return readb_relaxed(nfc->regs + reg);
+}
+
+static void mtk_nfc_hw_reset(struct mtk_nfc *nfc)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	/* reset all registers and force the NFI master to terminate */
+	nfi_writel(nfc, CON_FIFO_FLUSH | CON_NFI_RST, NFI_CON);
+
+	/* wait for the master to finish the last transaction */
+	ret = readl_poll_timeout(nfc->regs + NFI_MASTER_STA, val,
+			!(val & MASTER_STA_MASK), 50, MTK_RESET_TIMEOUT);
+	if (ret)
+		dev_warn(dev, "master active in reset [0x%x] = 0x%x\n",
+			NFI_MASTER_STA, val);
+
+	/* ensure any status register affected by the NFI master is reset */
+	nfi_writel(nfc, CON_FIFO_FLUSH | CON_NFI_RST, NFI_CON);
+	nfi_writew(nfc, STAR_DE, NFI_STRDATA);
+}
+
+static int mtk_nfc_send_command(struct mtk_nfc *nfc, u8 command)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	nfi_writel(nfc, command, NFI_CMD);
+
+	ret = readl_poll_timeout_atomic(nfc->regs + NFI_STA, val,
+					!(val & STA_CMD), 10,  MTK_TIMEOUT);
+	if (ret) {
+		dev_warn(dev, "nfi core timed out entering command mode\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int mtk_nfc_send_address(struct mtk_nfc *nfc, int addr)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	nfi_writel(nfc, addr, NFI_COLADDR);
+	nfi_writel(nfc, 0, NFI_ROWADDR);
+	nfi_writew(nfc, 1, NFI_ADDRNOB);
+
+	ret = readl_poll_timeout_atomic(nfc->regs + NFI_STA, val,
+					!(val & STA_ADDR), 10, MTK_TIMEOUT);
+	if (ret) {
+		dev_warn(dev, "nfi core timed out entering address mode\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int mtk_nfc_hw_runtime_config(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	u32 fmt, spare;
+
+	if (!mtd->writesize)
+		return 0;
+
+	spare = mtk_nand->spare_per_sector;
+
+	switch (mtd->writesize) {
+	case 512:
+		fmt = PAGEFMT_512_2K | PAGEFMT_SEC_SEL_512;
+		break;
+	case KB(2):
+		if (chip->ecc.size == 512)
+			fmt = PAGEFMT_2K_4K | PAGEFMT_SEC_SEL_512;
+		else
+			fmt = PAGEFMT_512_2K;
+		break;
+	case KB(4):
+		if (chip->ecc.size == 512)
+			fmt = PAGEFMT_4K_8K | PAGEFMT_SEC_SEL_512;
+		else
+			fmt = PAGEFMT_2K_4K;
+		break;
+	case KB(8):
+		if (chip->ecc.size == 512)
+			fmt = PAGEFMT_8K_16K | PAGEFMT_SEC_SEL_512;
+		else
+			fmt = PAGEFMT_4K_8K;
+		break;
+	case KB(16):
+		fmt = PAGEFMT_8K_16K;
+		break;
+	default:
+		dev_err(nfc->dev, "invalid page len: %d\n", mtd->writesize);
+		return -EINVAL;
+	}
+
+	/* the hardware doubles the value for this eccsize so let's halve it */
+	if (chip->ecc.size == 1024)
+		spare >>= 1;
+
+	switch (spare) {
+	case 16:
+		fmt |= (PAGEFMT_SPARE_16 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 26:
+		fmt |= (PAGEFMT_SPARE_26 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 27:
+		fmt |= (PAGEFMT_SPARE_27 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 28:
+		fmt |= (PAGEFMT_SPARE_28 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 32:
+		fmt |= (PAGEFMT_SPARE_32 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 36:
+		fmt |= (PAGEFMT_SPARE_36 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 40:
+		fmt |= (PAGEFMT_SPARE_40 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 44:
+		fmt |= (PAGEFMT_SPARE_44 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 48:
+		fmt |= (PAGEFMT_SPARE_48 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 49:
+		fmt |= (PAGEFMT_SPARE_49 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 50:
+		fmt |= (PAGEFMT_SPARE_50 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 51:
+		fmt |= (PAGEFMT_SPARE_51 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 52:
+		fmt |= (PAGEFMT_SPARE_52 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 62:
+		fmt |= (PAGEFMT_SPARE_62 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 63:
+		fmt |= (PAGEFMT_SPARE_63 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 64:
+		fmt |= (PAGEFMT_SPARE_64 << PAGEFMT_SPARE_SHIFT);
+		break;
+	default:
+		dev_err(nfc->dev, "invalid spare per sector %d\n", spare);
+		return -EINVAL;
+	}
+
+	fmt |= mtk_nand->fdm.reg_size << PAGEFMT_FDM_SHIFT;
+	fmt |= mtk_nand->fdm.ecc_size << PAGEFMT_FDM_ECC_SHIFT;
+	nfi_writew(nfc, fmt, NFI_PAGEFMT);
+
+	nfc->ecc_cfg.strength = chip->ecc.strength;
+	nfc->ecc_cfg.enc_len = chip->ecc.size + mtk_nand->fdm.ecc_size;
+	nfc->ecc_cfg.dec_len = (nfc->ecc_cfg.enc_len << 3)
+				+ chip->ecc.strength * ECC_PARITY_BITS;
+
+	return 0;
+}
+
+static void mtk_nfc_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct mtk_nfc *nfc = nand_get_controller_data(nand);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(nand);
+
+	if (chip < 0)
+		return;
+
+	mtk_nfc_hw_runtime_config(mtd);
+
+	nfi_writel(nfc, mtk_nand->sels[chip], NFI_CSEL);
+}
+
+static int mtk_nfc_dev_ready(struct mtd_info *mtd)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
+
+	if (nfi_readl(nfc, NFI_STA) & STA_BUSY)
+		return 0;
+
+	return 1;
+}
+
+static void mtk_nfc_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
+
+	if (ctrl & NAND_ALE)
+		mtk_nfc_send_address(nfc, dat);
+	else if (ctrl & NAND_CLE) {
+		mtk_nfc_hw_reset(nfc);
+
+		nfi_writew(nfc, CNFG_OP_CUST, NFI_CNFG);
+		mtk_nfc_send_command(nfc, dat);
+	}
+}
+
+static inline void mtk_nfc_wait_ioready(struct mtk_nfc *nfc)
+{
+	int rc;
+	u8 val;
+
+	rc = readb_poll_timeout_atomic(nfc->regs + NFI_PIO_DIRDY, val,
+					val & PIO_DI_RDY, 10, MTK_TIMEOUT);
+	if (rc < 0)
+		dev_err(nfc->dev, "data not ready\n");
+}
+
+static inline uint8_t mtk_nfc_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	u32 reg;
+
+	reg = nfi_readl(nfc, NFI_STA) & NFI_FSM_MASK;
+	if (reg != NFI_FSM_CUSTDATA) {
+		reg = nfi_readw(nfc, NFI_CNFG);
+		reg |= CNFG_BYTE_RW | CNFG_READ_EN;
+		nfi_writew(nfc, reg, NFI_CNFG);
+
+		reg = (MTK_MAX_SECTOR << CON_SEC_SHIFT) | CON_BRD;
+		nfi_writel(nfc, reg, NFI_CON);
+
+		/* trigger to fetch data */
+		nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+	}
+
+	mtk_nfc_wait_ioready(nfc);
+
+	return nfi_readb(nfc, NFI_DATAR);
+}
+
+static void mtk_nfc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		buf[i] = mtk_nfc_read_byte(mtd);
+}
+
+static void mtk_nfc_write_byte(struct mtd_info *mtd, uint8_t byte)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
+	u32 reg;
+
+	reg = nfi_readl(nfc, NFI_STA) & NFI_FSM_MASK;
+
+	if (reg != NFI_FSM_CUSTDATA) {
+		reg = nfi_readw(nfc, NFI_CNFG) | CNFG_BYTE_RW;
+		nfi_writew(nfc, reg, NFI_CNFG);
+
+		reg = MTK_MAX_SECTOR << CON_SEC_SHIFT | CON_BWR;
+		nfi_writel(nfc, reg, NFI_CON);
+
+		nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+	}
+
+	mtk_nfc_wait_ioready(nfc);
+	nfi_writeb(nfc, byte, NFI_DATAW);
+}
+
+static void mtk_nfc_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		mtk_nfc_write_byte(mtd, buf[i]);
+}
+
+static int mtk_nfc_sector_encode(struct nand_chip *chip, u8 *data)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	int size = chip->ecc.size + mtk_nand->fdm.reg_size;
+
+	nfc->ecc_cfg.ecc_mode = ECC_DMA_MODE;
+	nfc->ecc_cfg.codec = ECC_ENC;
+	return mtk_ecc_encode_non_nfi_mode(nfc->ecc, &nfc->ecc_cfg, data, size);
+}
+
+static void mtk_nfc_no_bad_mark_swap(struct mtd_info *a, uint8_t *b, int c)
+{
+	/* nope */
+}
+
+static void mtk_nfc_bad_mark_swap(struct mtd_info *mtd, uint8_t *buf, int raw)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *nand = to_mtk_nand(chip);
+	u32 bad_pos = nand->bad_mark.pos;
+
+	if (raw)
+		bad_pos += nand->bad_mark.sec * mtk_data_len(chip);
+	else
+		bad_pos += nand->bad_mark.sec * chip->ecc.size;
+
+	swap(chip->oob_poi[0], buf[bad_pos]);
+}
+
+static int mtk_nfc_format_subpage(struct mtd_info *mtd, uint32_t offset,
+			uint32_t len, const uint8_t *buf)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 start, end;
+	int i, ret;
+
+	start = offset / chip->ecc.size;
+	end = DIV_ROUND_UP(offset + len, chip->ecc.size);
+
+	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
+	for (i = 0; i < chip->ecc.steps; i++) {
+
+		memcpy(mtk_data_ptr(chip, i), data_ptr(chip, buf, i),
+			chip->ecc.size);
+
+		if (start > i || i >= end)
+			continue;
+
+		if (i == mtk_nand->bad_mark.sec)
+			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
+
+		memcpy(mtk_oob_ptr(chip, i), oob_ptr(chip, i), fdm->reg_size);
+
+		/* program the CRC back to the OOB */
+		ret = mtk_nfc_sector_encode(chip, mtk_data_ptr(chip, i));
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void mtk_nfc_format_page(struct mtd_info *mtd, const uint8_t *buf)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 i;
+
+	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
+	for (i = 0; i < chip->ecc.steps; i++) {
+		if (buf)
+			memcpy(mtk_data_ptr(chip, i), data_ptr(chip, buf, i),
+				chip->ecc.size);
+
+		if (i == mtk_nand->bad_mark.sec)
+			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
+
+		memcpy(mtk_oob_ptr(chip, i), oob_ptr(chip, i), fdm->reg_size);
+	}
+}
+
+static inline void mtk_nfc_read_fdm(struct nand_chip *chip, u32 start,
+					u32 sectors)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	u32 *p;
+	int i;
+
+	for (i = 0; i < sectors; i++) {
+		p = (u32 *) oob_ptr(chip, start + i);
+		p[0] = nfi_readl(nfc, NFI_FDML(i));
+		p[1] = nfi_readl(nfc, NFI_FDMM(i));
+	}
+}
+
+static inline void mtk_nfc_write_fdm(struct nand_chip *chip)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	u32 *p;
+	int i;
+
+	for (i = 0; i < chip->ecc.steps ; i++) {
+		p = (u32 *) oob_ptr(chip, i);
+		nfi_writel(nfc, p[0], NFI_FDML(i));
+		nfi_writel(nfc, p[1], NFI_FDMM(i));
+	}
+}
+
+static int mtk_nfc_do_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+				const uint8_t *buf, int page, int len)
+{
+
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct device *dev = nfc->dev;
+	dma_addr_t addr;
+	u32 reg;
+	int ret;
+
+	addr = dma_map_single(dev, (void *) buf, len, DMA_TO_DEVICE);
+	ret = dma_mapping_error(nfc->dev, addr);
+	if (ret) {
+		dev_err(nfc->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	reg = nfi_readw(nfc, NFI_CNFG) | CNFG_AHB | CNFG_DMA_BURST_EN;
+	nfi_writew(nfc, reg, NFI_CNFG);
+
+	nfi_writel(nfc, chip->ecc.steps << CON_SEC_SHIFT, NFI_CON);
+	nfi_writel(nfc, lower_32_bits(addr), NFI_STRADDR);
+	nfi_writew(nfc, INTR_AHB_DONE_EN, NFI_INTR_EN);
+
+	init_completion(&nfc->done);
+
+	reg = nfi_readl(nfc, NFI_CON) | CON_BWR;
+	nfi_writel(nfc, reg, NFI_CON);
+	nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+
+	ret = wait_for_completion_timeout(&nfc->done, msecs_to_jiffies(500));
+	if (!ret) {
+		dev_err(dev, "program ahb done timeout\n");
+		nfi_writew(nfc, 0, NFI_INTR_EN);
+		ret = -ETIMEDOUT;
+		goto timeout;
+	}
+
+	ret = readl_poll_timeout_atomic(nfc->regs + NFI_ADDRCNTR, reg,
+			(reg & CNTR_MASK) >= chip->ecc.steps, 10, MTK_TIMEOUT);
+	if (ret)
+		dev_err(dev, "hwecc write timeout\n");
+
+timeout:
+
+	dma_unmap_single(nfc->dev, addr, len, DMA_TO_DEVICE);
+	nfi_writel(nfc, 0, NFI_CON);
+
+	return ret;
+}
+
+static int mtk_nfc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+			const uint8_t *buf, int page, int raw)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	size_t len;
+	const u8 *bufpoi;
+	u32 reg;
+	int ret;
+
+	if (!raw) {
+		/* OOB => FDM: from register,  ECC: from HW */
+		reg = nfi_readw(nfc, NFI_CNFG) | CNFG_AUTO_FMT_EN;
+		nfi_writew(nfc, reg | CNFG_HW_ECC_EN, NFI_CNFG);
+
+		nfc->ecc_cfg.codec = ECC_ENC;
+		nfc->ecc_cfg.ecc_mode = ECC_NFI_MODE;
+		ret = mtk_ecc_enable(nfc->ecc, &nfc->ecc_cfg);
+		if (ret) {
+			/* clear NFI config */
+			reg = nfi_readw(nfc, NFI_CNFG);
+			reg &= ~(CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN);
+			nfi_writew(nfc, reg, NFI_CNFG);
+
+			return ret;
+		}
+
+		memcpy(nfc->buffer, buf, mtd->writesize);
+		mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, raw);
+		bufpoi = nfc->buffer;
+
+		/* write OOB into the FDM registers (OOB area in MTK NAND) */
+		mtk_nfc_write_fdm(chip);
+	} else
+		bufpoi = buf;
+
+	len = mtd->writesize + (raw ? mtd->oobsize : 0);
+	ret = mtk_nfc_do_write_page(mtd, chip, bufpoi, page, len);
+
+	if (!raw)
+		mtk_ecc_disable(nfc->ecc, &nfc->ecc_cfg);
+
+	return ret;
+}
+
+static int mtk_nfc_write_page_hwecc(struct mtd_info *mtd,
+	struct nand_chip *chip, const uint8_t *buf, int oob_on, int page)
+{
+	return mtk_nfc_write_page(mtd, chip, buf, page, 0);
+}
+
+static int mtk_nfc_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+				const uint8_t *buf, int oob_on, int pg)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+
+	mtk_nfc_format_page(mtd, buf);
+	return mtk_nfc_write_page(mtd, chip, nfc->buffer, pg, 1);
+}
+
+static int mtk_nfc_write_subpage_hwecc(struct mtd_info *mtd,
+		struct nand_chip *chip, uint32_t offset, uint32_t data_len,
+		const uint8_t *buf, int oob_on, int page)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	int ret;
+
+	ret = mtk_nfc_format_subpage(mtd, offset, data_len, buf);
+	if (ret < 0)
+		return ret;
+
+	/* use the data in the private buffer (now with FDM and CRC) */
+	return mtk_nfc_write_page(mtd, chip, nfc->buffer, page, 1);
+}
+
+static int mtk_nfc_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
+					int page)
+{
+	int ret;
+
+	chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
+
+	ret = mtk_nfc_write_page_raw(mtd, chip, NULL, 1, page);
+	if (ret < 0)
+		return -EIO;
+
+	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+	ret = chip->waitfunc(mtd, chip);
+
+	return ret & NAND_STATUS_FAIL ? -EIO : 0;
+}
+
+static int mtk_nfc_update_ecc_stats(struct mtd_info *mtd, u8 *buf, u32 sectors)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_ecc_stats stats;
+	int rc, i;
+
+	rc = nfi_readl(nfc, NFI_STA) & STA_EMP_PAGE;
+	if (rc) {
+		memset(buf, 0xff, sectors * chip->ecc.size);
+		for (i = 0; i < sectors; i++)
+			memset(oob_ptr(chip, i), 0xff, mtk_nand->fdm.reg_size);
+		return 0;
+	}
+
+	mtk_ecc_get_stats(nfc->ecc, &stats, sectors);
+	mtd->ecc_stats.corrected += stats.corrected;
+	mtd->ecc_stats.failed += stats.failed;
+
+	return stats.bitflips;
+}
+
+static int mtk_nfc_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
+		uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi,
+		int page, int raw)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	u32 spare = mtk_nand->spare_per_sector;
+	u32 column, sectors, start, end, reg;
+	dma_addr_t addr;
+	int bitflips;
+	size_t len;
+	u8 *buf;
+	int rc;
+
+	start = data_offs / chip->ecc.size;
+	end = DIV_ROUND_UP(data_offs + readlen, chip->ecc.size);
+
+	sectors = end - start;
+	column = start * (chip->ecc.size + spare);
+
+	len = sectors * chip->ecc.size + (raw ? sectors * spare : 0);
+	buf = bufpoi + start * chip->ecc.size;
+
+	if (column != 0)
+		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, column, -1);
+
+	addr = dma_map_single(nfc->dev, buf, len, DMA_FROM_DEVICE);
+	rc = dma_mapping_error(nfc->dev, addr);
+	if (rc) {
+		dev_err(nfc->dev, "dma mapping error\n");
+
+		return -EINVAL;
+	}
+
+	reg = nfi_readw(nfc, NFI_CNFG);
+	reg |= CNFG_READ_EN | CNFG_DMA_BURST_EN | CNFG_AHB;
+	if (!raw) {
+		reg |= CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN;
+		nfi_writew(nfc, reg, NFI_CNFG);
+
+		nfc->ecc_cfg.ecc_mode = ECC_NFI_MODE;
+		nfc->ecc_cfg.sec_mask = sectors;
+		nfc->ecc_cfg.codec = ECC_DEC;
+		rc = mtk_ecc_enable(nfc->ecc, &nfc->ecc_cfg);
+		if (rc) {
+			dev_err(nfc->dev, "ecc enable\n");
+			/* clear NFI_CNFG */
+			reg &= ~(CNFG_DMA_BURST_EN | CNFG_AHB | CNFG_READ_EN |
+				CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN);
+			nfi_writew(nfc, reg, NFI_CNFG);
+			dma_unmap_single(nfc->dev, addr, len, DMA_FROM_DEVICE);
+
+			return rc;
+		}
+	} else
+		nfi_writew(nfc, reg, NFI_CNFG);
+
+	nfi_writel(nfc, sectors << CON_SEC_SHIFT, NFI_CON);
+	nfi_writew(nfc, INTR_AHB_DONE_EN, NFI_INTR_EN);
+	nfi_writel(nfc, lower_32_bits(addr), NFI_STRADDR);
+
+	init_completion(&nfc->done);
+	reg = nfi_readl(nfc, NFI_CON) | CON_BRD;
+	nfi_writel(nfc, reg, NFI_CON);
+	nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+
+	rc = wait_for_completion_timeout(&nfc->done, msecs_to_jiffies(500));
+	if (!rc)
+		dev_warn(nfc->dev, "read ahb/dma done timeout\n");
+
+	rc = readl_poll_timeout_atomic(nfc->regs + NFI_BYTELEN, reg,
+				(reg & CNTR_MASK) >= sectors, 10, MTK_TIMEOUT);
+	if (rc < 0) {
+		dev_err(nfc->dev, "subpage done timeout\n");
+		bitflips = -EIO;
+	} else {
+		bitflips = 0;
+		if (!raw) {
+			rc = mtk_ecc_wait_irq_done(nfc->ecc, ECC_DEC);
+			bitflips = rc < 0 ? -ETIMEDOUT :
+				mtk_nfc_update_ecc_stats(mtd, buf, sectors);
+			mtk_nfc_read_fdm(chip, start, sectors);
+		}
+	}
+
+	dma_unmap_single(nfc->dev, addr, len, DMA_FROM_DEVICE);
+
+	if (raw)
+		goto done;
+
+	mtk_ecc_disable(nfc->ecc, &nfc->ecc_cfg);
+
+	if (clamp(mtk_nand->bad_mark.sec, start, end) == mtk_nand->bad_mark.sec)
+		mtk_nand->bad_mark.bm_swap(mtd, bufpoi, raw);
+done:
+	nfi_writel(nfc, 0, NFI_CON);
+
+	return bitflips;
+}
+
+static int mtk_nfc_read_subpage_hwecc(struct mtd_info *mtd,
+	struct nand_chip *chip, uint32_t off, uint32_t len, uint8_t *p, int pg)
+{
+	return mtk_nfc_read_subpage(mtd, chip, off, len, p, pg, 0);
+}
+
+static int mtk_nfc_read_page_hwecc(struct mtd_info *mtd,
+	struct nand_chip *chip, uint8_t *p, int oob_on, int pg)
+{
+	return mtk_nfc_read_subpage(mtd, chip, 0, mtd->writesize, p, pg, 0);
+}
+
+static int mtk_nfc_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+				uint8_t *buf, int oob_on, int page)
+{
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	int i, ret;
+
+	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
+	ret = mtk_nfc_read_subpage(mtd, chip, 0, mtd->writesize, nfc->buffer,
+					page, 1);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < chip->ecc.steps; i++) {
+		memcpy(oob_ptr(chip, i), mtk_oob_ptr(chip, i), fdm->reg_size);
+		if (i == mtk_nand->bad_mark.sec)
+			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
+
+		if (buf)
+			memcpy(data_ptr(chip, buf, i), mtk_data_ptr(chip, i),
+				chip->ecc.size);
+	}
+
+	return ret;
+}
+
+static int mtk_nfc_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
+				int page)
+{
+	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
+
+	return mtk_nfc_read_page_raw(mtd, chip, NULL, 1, page);
+}
+
+static inline void mtk_nfc_hw_init(struct mtk_nfc *nfc)
+{
+	nfi_writel(nfc, 0x10804211, NFI_ACCCON);
+	nfi_writew(nfc, 0xf1, NFI_CNRNB);
+	nfi_writew(nfc, PAGEFMT_8K_16K, NFI_PAGEFMT);
+
+	mtk_nfc_hw_reset(nfc);
+
+	nfi_readl(nfc, NFI_INTR_STA);
+	nfi_writel(nfc, 0, NFI_INTR_EN);
+}
+
+static irqreturn_t mtk_nfc_irq(int irq, void *id)
+{
+	struct mtk_nfc *nfc = id;
+	u16 sta, ien;
+
+	sta = nfi_readw(nfc, NFI_INTR_STA);
+	ien = nfi_readw(nfc, NFI_INTR_EN);
+
+	if (!(sta & ien))
+		return IRQ_NONE;
+
+	nfi_writew(nfc, ~sta & ien, NFI_INTR_EN);
+	complete(&nfc->done);
+
+	return IRQ_HANDLED;
+}
+
+static int mtk_nfc_enable_clk(struct device *dev, struct mtk_nfc_clk *clk)
+{
+	int ret;
+
+	ret = clk_prepare_enable(clk->nfi_clk);
+	if (ret) {
+		dev_err(dev, "failed to enable nfi clk\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(clk->pad_clk);
+	if (ret) {
+		dev_err(dev, "failed to enable pad clk\n");
+		clk_disable_unprepare(clk->nfi_clk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void mtk_nfc_disable_clk(struct mtk_nfc_clk *clk)
+{
+	clk_disable_unprepare(clk->nfi_clk);
+	clk_disable_unprepare(clk->pad_clk);
+}
+
+static int mtk_nfc_ooblayout_free(struct mtd_info *mtd, int section,
+				struct mtd_oob_region *oob_region)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 eccsteps;
+
+	eccsteps = mtd->writesize / chip->ecc.size;
+
+	if (section >= eccsteps)
+		return -ERANGE;
+
+	oob_region->length = fdm->reg_size - fdm->ecc_size;
+	oob_region->offset = section * fdm->reg_size + fdm->ecc_size;
+
+	return 0;
+}
+
+static int mtk_nfc_ooblayout_ecc(struct mtd_info *mtd, int section,
+				struct mtd_oob_region *oob_region)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	u32 eccsteps;
+
+	if (section)
+		return -ERANGE;
+
+	eccsteps = mtd->writesize / chip->ecc.size;
+	oob_region->offset = mtk_nand->fdm.reg_size * eccsteps;
+	oob_region->length = mtd->oobsize - oob_region->offset;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops mtk_nfc_ooblayout_ops = {
+	.free = mtk_nfc_ooblayout_free,
+	.ecc = mtk_nfc_ooblayout_ecc,
+};
+
+static void mtk_nfc_set_fdm(struct mtk_nfc_fdm *fdm, struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *chip = to_mtk_nand(nand);
+	u32 ecc_bytes;
+
+	ecc_bytes = DIV_ROUND_UP(nand->ecc.strength * ECC_PARITY_BITS, 8);
+
+	fdm->reg_size = chip->spare_per_sector - ecc_bytes;
+	if (fdm->reg_size > NFI_FDM_MAX_SIZE)
+		fdm->reg_size = NFI_FDM_MAX_SIZE;
+
+	/* bad block mark storage */
+	fdm->ecc_size = 1;
+}
+
+static void mtk_nfc_set_bad_mark_ctl(struct mtk_nfc_bad_mark_ctl *bm_ctl,
+				struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+
+	if (mtd->writesize == 512)
+		bm_ctl->bm_swap = mtk_nfc_no_bad_mark_swap;
+	else {
+		bm_ctl->bm_swap = mtk_nfc_bad_mark_swap;
+		bm_ctl->sec = mtd->writesize / mtk_data_len(nand);
+		bm_ctl->pos = mtd->writesize % mtk_data_len(nand);
+	}
+}
+
+static void mtk_nfc_set_spare_per_sector(u32 *sps, struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	u32 spare[] = {16, 26, 27, 28, 32, 36, 40, 44,
+			48, 49, 50, 51, 52, 62, 63, 64};
+	u32 eccsteps, i;
+
+	eccsteps = mtd->writesize / nand->ecc.size;
+	*sps = mtd->oobsize / eccsteps;
+
+	if (nand->ecc.size == 1024)
+		*sps >>= 1;
+
+	for (i = 0; i < ARRAY_SIZE(spare); i++) {
+		if (*sps <= spare[i]) {
+			if (!i)
+				*sps = spare[i];
+			else if (*sps != spare[i])
+				*sps = spare[i - 1];
+			break;
+		}
+	}
+
+	if (i >= ARRAY_SIZE(spare))
+		*sps = spare[ARRAY_SIZE(spare) - 1];
+
+	if (nand->ecc.size == 1024)
+		*sps <<= 1;
+}
+
+static int mtk_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	u32 spare;
+
+	/* support only ecc hw mode */
+	if (nand->ecc.mode != NAND_ECC_HW) {
+		dev_err(dev, "ecc.mode not supported\n");
+		return -EINVAL;
+	}
+
+	/* if optional DT settings are not present */
+	if (!nand->ecc.size || !nand->ecc.strength) {
+
+		/* controller only supports sizes 512 and 1024 */
+		nand->ecc.size = (mtd->writesize > 512) ? 1024 : 512;
+
+		/* get controller valid values */
+		mtk_nfc_set_spare_per_sector(&spare, mtd);
+		spare = spare - NFI_FDM_MAX_SIZE;
+		nand->ecc.strength = (spare << 3) / ECC_PARITY_BITS;
+	}
+
+	mtk_ecc_update_strength(&nand->ecc.strength);
+
+	dev_info(dev, "eccsize %d eccstrength %d\n",
+		nand->ecc.size, nand->ecc.strength);
+
+	return 0;
+}
+
+static int mtk_nfc_nand_chip_init(struct device *dev, struct mtk_nfc *nfc,
+				struct device_node *np)
+{
+	struct mtk_nfc_nand_chip *chip;
+	struct nand_chip *nand;
+	struct mtd_info *mtd;
+	int nsels, len;
+	u32 tmp;
+	int ret;
+	int i;
+
+	if (!of_get_property(np, "reg", &nsels))
+		return -ENODEV;
+
+	nsels /= sizeof(u32);
+	if (!nsels || nsels > MTK_NAND_MAX_NSELS) {
+		dev_err(dev, "invalid reg property size %d\n", nsels);
+		return -EINVAL;
+	}
+
+	chip = devm_kzalloc(dev,
+			sizeof(*chip) + nsels * sizeof(u8), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->nsels = nsels;
+	for (i = 0; i < nsels; i++) {
+		ret = of_property_read_u32_index(np, "reg", i, &tmp);
+		if (ret) {
+			dev_err(dev, "reg property failure : %d\n", ret);
+			return ret;
+		}
+		chip->sels[i] = tmp;
+	}
+
+	nand = &chip->nand;
+	nand->controller = &nfc->controller;
+
+	nand_set_flash_node(nand, np);
+	nand_set_controller_data(nand, nfc);
+
+	nand->options |= NAND_USE_BOUNCE_BUFFER | NAND_SUBPAGE_READ;
+	nand->dev_ready = mtk_nfc_dev_ready;
+	nand->select_chip = mtk_nfc_select_chip;
+	nand->write_byte = mtk_nfc_write_byte;
+	nand->write_buf = mtk_nfc_write_buf;
+	nand->read_byte = mtk_nfc_read_byte;
+	nand->read_buf = mtk_nfc_read_buf;
+	nand->cmd_ctrl = mtk_nfc_cmd_ctrl;
+
+	/* set default mode in case dt entry is missing */
+	nand->ecc.mode = NAND_ECC_HW;
+
+	nand->ecc.write_subpage = mtk_nfc_write_subpage_hwecc;
+	nand->ecc.write_page_raw = mtk_nfc_write_page_raw;
+	nand->ecc.write_page = mtk_nfc_write_page_hwecc;
+	nand->ecc.write_oob_raw = mtk_nfc_write_oob_std;
+	nand->ecc.write_oob = mtk_nfc_write_oob_std;
+
+	nand->ecc.read_subpage = mtk_nfc_read_subpage_hwecc;
+	nand->ecc.read_page_raw = mtk_nfc_read_page_raw;
+	nand->ecc.read_page = mtk_nfc_read_page_hwecc;
+	nand->ecc.read_oob_raw = mtk_nfc_read_oob_std;
+	nand->ecc.read_oob = mtk_nfc_read_oob_std;
+
+	mtd = nand_to_mtd(nand);
+	mtd->owner = THIS_MODULE;
+	mtd->dev.parent = dev;
+	mtd->name = MTK_NAME;
+	mtd_set_ooblayout(mtd, &mtk_nfc_ooblayout_ops);
+
+	mtk_nfc_hw_init(nfc);
+
+	ret = nand_scan_ident(mtd, nsels, NULL);
+	if (ret)
+		return -ENODEV;
+
+	/* store bbt magic in page, cause OOB is not protected */
+	if (nand->bbt_options & NAND_BBT_USE_FLASH)
+		nand->bbt_options |= NAND_BBT_NO_OOB;
+
+	ret = mtk_nfc_ecc_init(dev, mtd);
+	if (ret)
+		return -EINVAL;
+
+	mtk_nfc_set_spare_per_sector(&chip->spare_per_sector, mtd);
+	mtk_nfc_set_fdm(&chip->fdm, mtd);
+	mtk_nfc_set_bad_mark_ctl(&chip->bad_mark, mtd);
+
+	len = mtd->writesize + mtd->oobsize;
+	nfc->buffer = devm_kzalloc(dev, len, GFP_KERNEL);
+	if (!nfc->buffer)
+		return  -ENOMEM;
+
+	ret = nand_scan_tail(mtd);
+	if (ret)
+		return -ENODEV;
+
+	ret = mtd_device_parse_register(mtd, NULL, NULL, NULL, 0);
+	if (ret) {
+		dev_err(dev, "mtd parse partition error\n");
+		nand_release(mtd);
+		return ret;
+	}
+
+	list_add_tail(&chip->node, &nfc->chips);
+
+	return 0;
+}
+
+static int mtk_nfc_nand_chips_init(struct device *dev, struct mtk_nfc *nfc)
+{
+	struct device_node *np = dev->of_node;
+	struct device_node *nand_np;
+	int ret;
+
+	for_each_child_of_node(np, nand_np) {
+		ret = mtk_nfc_nand_chip_init(dev, nfc, nand_np);
+		if (ret) {
+			of_node_put(nand_np);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int mtk_nfc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct mtk_nfc *nfc;
+	struct resource *res;
+	int ret, irq;
+
+	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
+	if (!nfc)
+		return -ENOMEM;
+
+	spin_lock_init(&nfc->controller.lock);
+	init_waitqueue_head(&nfc->controller.wq);
+	INIT_LIST_HEAD(&nfc->chips);
+
+	/* probe defer if not ready */
+	nfc->ecc = of_mtk_ecc_get(np);
+	if (IS_ERR(nfc->ecc))
+		return PTR_ERR(nfc->ecc);
+	else if (!nfc->ecc)
+		return -ENODEV;
+
+	nfc->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	nfc->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(nfc->regs)) {
+		ret = PTR_ERR(nfc->regs);
+		dev_err(dev, "no nfi base\n");
+		goto release_ecc;
+	}
+
+	nfc->clk.nfi_clk = devm_clk_get(dev, "nfi_clk");
+	if (IS_ERR(nfc->clk.nfi_clk)) {
+		dev_err(dev, "no clk\n");
+		ret = PTR_ERR(nfc->clk.nfi_clk);
+		goto release_ecc;
+	}
+
+	nfc->clk.pad_clk = devm_clk_get(dev, "pad_clk");
+	if (IS_ERR(nfc->clk.pad_clk)) {
+		dev_err(dev, "no pad clk\n");
+		ret = PTR_ERR(nfc->clk.pad_clk);
+		goto release_ecc;
+	}
+
+	ret = mtk_nfc_enable_clk(dev, &nfc->clk);
+	if (ret)
+		goto release_ecc;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "no nfi irq resource\n");
+		ret = -EINVAL;
+		goto clk_disable;
+	}
+
+	ret = devm_request_irq(dev, irq, mtk_nfc_irq, 0x0, "mtk-nand", nfc);
+	if (ret) {
+		dev_err(dev, "failed to request nfi irq\n");
+		goto clk_disable;
+	}
+
+	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dev, "failed to set dma mask\n");
+		goto clk_disable;
+	}
+
+	platform_set_drvdata(pdev, nfc);
+
+	ret = mtk_nfc_nand_chips_init(dev, nfc);
+	if (ret) {
+		dev_err(dev, "failed to init nand chips\n");
+		goto clk_disable;
+	}
+
+	return 0;
+
+clk_disable:
+	mtk_nfc_disable_clk(&nfc->clk);
+
+release_ecc:
+	mtk_ecc_release(nfc->ecc);
+
+	return ret;
+}
+
+static int mtk_nfc_remove(struct platform_device *pdev)
+{
+	struct mtk_nfc *nfc = platform_get_drvdata(pdev);
+	struct mtk_nfc_nand_chip *chip;
+
+	while (!list_empty(&nfc->chips)) {
+		chip = list_first_entry(&nfc->chips, struct mtk_nfc_nand_chip,
+					node);
+		nand_release(nand_to_mtd(&chip->nand));
+		list_del(&chip->node);
+	}
+
+	mtk_ecc_release(nfc->ecc);
+	mtk_nfc_disable_clk(&nfc->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_nfc_suspend(struct device *dev)
+{
+	struct mtk_nfc *nfc = dev_get_drvdata(dev);
+
+	mtk_nfc_disable_clk(&nfc->clk);
+
+	return 0;
+}
+
+static int mtk_nfc_resume(struct device *dev)
+{
+	struct mtk_nfc *nfc = dev_get_drvdata(dev);
+	struct mtk_nfc_nand_chip *chip;
+	struct nand_chip *nand;
+	struct mtd_info *mtd;
+	int ret;
+	u32 i;
+
+	udelay(200);
+
+	ret = mtk_nfc_enable_clk(dev, &nfc->clk);
+	if (ret)
+		return ret;
+
+	mtk_nfc_hw_init(nfc);
+
+	list_for_each_entry(chip, &nfc->chips, node) {
+		nand = &chip->nand;
+		mtd = nand_to_mtd(nand);
+		for (i = 0; i < chip->nsels; i++) {
+			nand->select_chip(mtd, i);
+			nand->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+		}
+	}
+
+	return 0;
+}
+static SIMPLE_DEV_PM_OPS(mtk_nfc_pm_ops, mtk_nfc_suspend, mtk_nfc_resume);
+#endif
+
+static const struct of_device_id mtk_nfc_id_table[] = {
+	{ .compatible = "mediatek,mt2701-nfc" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, mtk_nfc_id_table);
+
+static struct platform_driver mtk_nfc_driver = {
+	.probe  = mtk_nfc_probe,
+	.remove = mtk_nfc_remove,
+	.driver = {
+		.name  = MTK_NAME,
+		.of_match_table = mtk_nfc_id_table,
+#ifdef CONFIG_PM_SLEEP
+		.pm = &mtk_nfc_pm_ops,
+#endif
+	},
+};
+
+module_platform_driver(mtk_nfc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Xiaolei Li <xiaolei.li@mediatek.com>");
+MODULE_AUTHOR("Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>");
+MODULE_DESCRIPTION("MTK Nand Flash Controller Driver");