mtd: atmel_nand: add Nand Flash Controller (NFC) support

Nand Flash Controller (NFC) can handle automatic transfers, sending the
commands and address cycles to the NAND Flash.

To use NFC in this driver, user needs to add NFC child node in nand flash
driver. The NFC child node includes NFC's compatible string and regiters
of the address and size of NFC command registers, NFC registers (embedded
in HSMC) and NFC SRAM.
Also user need to set up the HSMC irq, which use to check whether nfc
command is finish or not.

This driver has been tested on SAMA5D3X-EK board with JFFS2, YAFFS,
UBIFS and mtd-utils.

I put the part of the mtd_speedtest result here for your information.
>From the mtd_speedtest, we can see the NFC will reduce the %50 of cpu load
when writing nand flash. No change when reading.
In the meantime, the speed will be slow about %8.

- commands use to test:
    #insmod /mnt/mtd_speedtest.ko dev=2 &
    #top -n 30 -d 1 | grep speedtest

- test result:

Before the patch:
=================================================
mtd_speedtest: MTD device: 2
mtd_speedtest: MTD device size 41943040, eraseblock size 131072, page size 2048, count of eraseblocks 320, pages per eraseblock 64, OOB size 64
  515   495 root     R     1164   0%  93% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  98% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  99% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock write speed is 5768 KiB/s
mtd_speedtest: testing eraseblock read speed
  515   495 root     R     1164   0%  92% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  91% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  94% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock read speed is 5932 KiB/s
mtd_speedtest: testing page write speed
  515   495 root     R     1164   0%  94% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  98% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  98% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page write speed is 5770 KiB/s
mtd_speedtest: testing page read speed
  515   495 root     R     1164   0%  91% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  89% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  91% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page read speed is 5910 KiB/s

After the patch:
=================================================
mtd_speedtest: MTD device: 2
mtd_speedtest: MTD device size 41943040, eraseblock size 131072, page size 2048, count of eraseblocks 320, pages per eraseblock 64, OOB size 64
mtd_speedtest: testing eraseblock write speed
  509   495 root     D     1164   0%  49% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  50% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  47% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock write speed is 5370 KiB/s
mtd_speedtest: testing eraseblock read speed
  509   495 root     R     1164   0%  92% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     R     1164   0%  91% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     R     1164   0%  95% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock read speed is 5715 KiB/s
mtd_speedtest: testing page write speed
  509   495 root     D     1164   0%  48% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  47% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  50% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page write speed is 5224 KiB/s
mtd_speedtest: testing page read speed
  509   495 root     R     1164   0%  89% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     R     1164   0%  94% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     R     1164   0%  93% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page read speed is 5641 KiB/s

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Documentation/devicetree/bindings/mtd/atmel-nand.txt

@@ -30,6 +30,12 @@ Optional properties:
   sector size 1024.
 - 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
+- Nand Flash Controller(NFC) is a slave driver under Atmel nand flash
+  - Required properties:
+    - compatible : "atmel,sama5d3-nfc".
+    - reg : should specify the address and size used for NFC command registers,
+            NFC registers and NFC Sram. NFC Sram address and size can be absent
+            if don't want to use it.
 
 Examples:
 nand0: nand@40000000,0 {
@@ -78,3 +84,22 @@ nand0: nand@40000000 {
 		...
 	};
 };
+
+/* for NFC supported chips */
+nand0: nand@40000000 {
+	compatible = "atmel,at91rm9200-nand";
+	#address-cells = <1>;
+	#size-cells = <1>;
+	ranges;
+        ...
+        nfc@70000000 {
+		compatible = "atmel,sama5d3-nfc";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		reg = <
+			0x70000000 0x10000000	/* NFC Command Registers */
+			0xffffc000 0x00000070	/* NFC HSMC regs */
+			0x00200000 0x00100000	/* NFC SRAM banks */
+		>;
+	};
+};

drivers/mtd/nand/atmel_nand.c

@@ -18,6 +18,9 @@
  *  Add Programmable Multibit ECC support for various AT91 SoC
  *     © Copyright 2012 ATMEL, Hong Xu
  *
+ *  Add Nand Flash Controller support for SAMA5 SoC
+ *     © Copyright 2013 ATMEL, Josh Wu (josh.wu@atmel.com)
+ *
  * 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.
@@ -37,8 +40,10 @@
 #include <linux/mtd/nand.h>
 #include <linux/mtd/partitions.h>
 
+#include <linux/delay.h>
 #include <linux/dmaengine.h>
 #include <linux/gpio.h>
+#include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/platform_data/atmel.h>
 
@@ -55,6 +60,7 @@ module_param(on_flash_bbt, int, 0);
 	__raw_writel((value), add + ATMEL_ECC_##reg)
 
 #include "atmel_nand_ecc.h"	/* Hardware ECC registers */
+#include "atmel_nand_nfc.h"	/* Nand Flash Controller definition */
 
 /* oob layout for large page size
  * bad block info is on bytes 0 and 1
@@ -82,6 +88,17 @@ static struct nand_ecclayout atmel_oobinfo_small = {
 	},
 };
 
+struct atmel_nfc {
+	void __iomem		*base_cmd_regs;
+	void __iomem		*hsmc_regs;
+	void __iomem		*sram_bank0;
+	dma_addr_t		sram_bank0_phys;
+
+	bool			is_initialized;
+	struct completion	comp_nfc;
+};
+static struct atmel_nfc	nand_nfc;
+
 struct atmel_nand_host {
 	struct nand_chip	nand_chip;
 	struct mtd_info		mtd;
@@ -94,6 +111,8 @@ struct atmel_nand_host {
 	struct completion	comp;
 	struct dma_chan		*dma_chan;
 
+	struct atmel_nfc	*nfc;
+
 	bool			has_pmecc;
 	u8			pmecc_corr_cap;
 	u16			pmecc_sector_size;
@@ -178,6 +197,56 @@ static int atmel_nand_device_ready(struct mtd_info *mtd)
                 !!host->board.rdy_pin_active_low;
 }
 
+/* Set up for hardware ready pin and enable pin. */
+static int atmel_nand_set_enable_ready_pins(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct atmel_nand_host *host = chip->priv;
+	int res = 0;
+
+	if (gpio_is_valid(host->board.rdy_pin)) {
+		res = devm_gpio_request(host->dev,
+				host->board.rdy_pin, "nand_rdy");
+		if (res < 0) {
+			dev_err(host->dev,
+				"can't request rdy gpio %d\n",
+				host->board.rdy_pin);
+			return res;
+		}
+
+		res = gpio_direction_input(host->board.rdy_pin);
+		if (res < 0) {
+			dev_err(host->dev,
+				"can't request input direction rdy gpio %d\n",
+				host->board.rdy_pin);
+			return res;
+		}
+
+		chip->dev_ready = atmel_nand_device_ready;
+	}
+
+	if (gpio_is_valid(host->board.enable_pin)) {
+		res = devm_gpio_request(host->dev,
+				host->board.enable_pin, "nand_enable");
+		if (res < 0) {
+			dev_err(host->dev,
+				"can't request enable gpio %d\n",
+				host->board.enable_pin);
+			return res;
+		}
+
+		res = gpio_direction_output(host->board.enable_pin, 1);
+		if (res < 0) {
+			dev_err(host->dev,
+				"can't request output direction enable gpio %d\n",
+				host->board.enable_pin);
+			return res;
+		}
+	}
+
+	return res;
+}
+
 /*
  * Minimal-overhead PIO for data access.
  */
@@ -1336,6 +1405,9 @@ static int atmel_of_init_port(struct atmel_nand_host *host,
 
 	host->has_pmecc = of_property_read_bool(np, "atmel,has-pmecc");
 
+	/* load the nfc driver if there is */
+	of_platform_populate(np, NULL, NULL, host->dev);
+
 	if (!(board->ecc_mode == NAND_ECC_HW) || !host->has_pmecc)
 		return 0;	/* Not using PMECC */
 
@@ -1447,6 +1519,239 @@ static int __init atmel_hw_nand_init_params(struct platform_device *pdev,
 	return 0;
 }
 
+/* SMC interrupt service routine */
+static irqreturn_t hsmc_interrupt(int irq, void *dev_id)
+{
+	struct atmel_nand_host *host = dev_id;
+	u32 status, mask, pending;
+	irqreturn_t ret = IRQ_HANDLED;
+
+	status = nfc_readl(host->nfc->hsmc_regs, SR);
+	mask = nfc_readl(host->nfc->hsmc_regs, IMR);
+	pending = status & mask;
+
+	if (pending & NFC_SR_XFR_DONE) {
+		complete(&host->nfc->comp_nfc);
+		nfc_writel(host->nfc->hsmc_regs, IDR, NFC_SR_XFR_DONE);
+	} else if (pending & NFC_SR_RB_EDGE) {
+		complete(&host->nfc->comp_nfc);
+		nfc_writel(host->nfc->hsmc_regs, IDR, NFC_SR_RB_EDGE);
+	} else if (pending & NFC_SR_CMD_DONE) {
+		complete(&host->nfc->comp_nfc);
+		nfc_writel(host->nfc->hsmc_regs, IDR, NFC_SR_CMD_DONE);
+	} else {
+		ret = IRQ_NONE;
+	}
+
+	return ret;
+}
+
+/* NFC(Nand Flash Controller) related functions */
+static int nfc_wait_interrupt(struct atmel_nand_host *host, u32 flag)
+{
+	unsigned long timeout;
+	init_completion(&host->nfc->comp_nfc);
+
+	/* Enable interrupt that need to wait for */
+	nfc_writel(host->nfc->hsmc_regs, IER, flag);
+
+	timeout = wait_for_completion_timeout(&host->nfc->comp_nfc,
+			msecs_to_jiffies(NFC_TIME_OUT_MS));
+	if (timeout)
+		return 0;
+
+	/* Time out to wait for the interrupt */
+	dev_err(host->dev, "Time out to wait for interrupt: 0x%08x\n", flag);
+	return -ETIMEDOUT;
+}
+
+static int nfc_send_command(struct atmel_nand_host *host,
+	unsigned int cmd, unsigned int addr, unsigned char cycle0)
+{
+	unsigned long timeout;
+	dev_dbg(host->dev,
+		"nfc_cmd: 0x%08x, addr1234: 0x%08x, cycle0: 0x%02x\n",
+		cmd, addr, cycle0);
+
+	timeout = jiffies + msecs_to_jiffies(NFC_TIME_OUT_MS);
+	while (nfc_cmd_readl(NFCADDR_CMD_NFCBUSY, host->nfc->base_cmd_regs)
+			& NFCADDR_CMD_NFCBUSY) {
+		if (time_after(jiffies, timeout)) {
+			dev_err(host->dev,
+				"Time out to wait CMD_NFCBUSY ready!\n");
+			return -ETIMEDOUT;
+		}
+	}
+	nfc_writel(host->nfc->hsmc_regs, CYCLE0, cycle0);
+	nfc_cmd_addr1234_writel(cmd, addr, host->nfc->base_cmd_regs);
+	return nfc_wait_interrupt(host, NFC_SR_CMD_DONE);
+}
+
+static int nfc_device_ready(struct mtd_info *mtd)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct atmel_nand_host *host = nand_chip->priv;
+	if (!nfc_wait_interrupt(host, NFC_SR_RB_EDGE))
+		return 1;
+	return 0;
+}
+
+static void nfc_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct atmel_nand_host *host = nand_chip->priv;
+
+	if (chip == -1)
+		nfc_writel(host->nfc->hsmc_regs, CTRL, NFC_CTRL_DISABLE);
+	else
+		nfc_writel(host->nfc->hsmc_regs, CTRL, NFC_CTRL_ENABLE);
+}
+
+static int nfc_make_addr(struct mtd_info *mtd, int column, int page_addr,
+		unsigned int *addr1234, unsigned int *cycle0)
+{
+	struct nand_chip *chip = mtd->priv;
+
+	int acycle = 0;
+	unsigned char addr_bytes[8];
+	int index = 0, bit_shift;
+
+	BUG_ON(addr1234 == NULL || cycle0 == NULL);
+
+	*cycle0 = 0;
+	*addr1234 = 0;
+
+	if (column != -1) {
+		if (chip->options & NAND_BUSWIDTH_16)
+			column >>= 1;
+		addr_bytes[acycle++] = column & 0xff;
+		if (mtd->writesize > 512)
+			addr_bytes[acycle++] = (column >> 8) & 0xff;
+	}
+
+	if (page_addr != -1) {
+		addr_bytes[acycle++] = page_addr & 0xff;
+		addr_bytes[acycle++] = (page_addr >> 8) & 0xff;
+		if (chip->chipsize > (128 << 20))
+			addr_bytes[acycle++] = (page_addr >> 16) & 0xff;
+	}
+
+	if (acycle > 4)
+		*cycle0 = addr_bytes[index++];
+
+	for (bit_shift = 0; index < acycle; bit_shift += 8)
+		*addr1234 += addr_bytes[index++] << bit_shift;
+
+	/* return acycle in cmd register */
+	return acycle << NFCADDR_CMD_ACYCLE_BIT_POS;
+}
+
+static void nfc_nand_command(struct mtd_info *mtd, unsigned int command,
+				int column, int page_addr)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct atmel_nand_host *host = chip->priv;
+	unsigned long timeout;
+	unsigned int nfc_addr_cmd = 0;
+
+	unsigned int cmd1 = command << NFCADDR_CMD_CMD1_BIT_POS;
+
+	/* Set default settings: no cmd2, no addr cycle. read from nand */
+	unsigned int cmd2 = 0;
+	unsigned int vcmd2 = 0;
+	int acycle = NFCADDR_CMD_ACYCLE_NONE;
+	int csid = NFCADDR_CMD_CSID_3;
+	int dataen = NFCADDR_CMD_DATADIS;
+	int nfcwr = NFCADDR_CMD_NFCRD;
+	unsigned int addr1234 = 0;
+	unsigned int cycle0 = 0;
+	bool do_addr = true;
+
+	dev_dbg(host->dev, "%s: cmd = 0x%02x, col = 0x%08x, page = 0x%08x\n",
+	     __func__, command, column, page_addr);
+
+	switch (command) {
+	case NAND_CMD_RESET:
+		nfc_addr_cmd = cmd1 | acycle | csid | dataen | nfcwr;
+		nfc_send_command(host, nfc_addr_cmd, addr1234, cycle0);
+		udelay(chip->chip_delay);
+
+		nfc_nand_command(mtd, NAND_CMD_STATUS, -1, -1);
+		timeout = jiffies + msecs_to_jiffies(NFC_TIME_OUT_MS);
+		while (!(chip->read_byte(mtd) & NAND_STATUS_READY)) {
+			if (time_after(jiffies, timeout)) {
+				dev_err(host->dev,
+					"Time out to wait status ready!\n");
+				break;
+			}
+		}
+		return;
+	case NAND_CMD_STATUS:
+		do_addr = false;
+		break;
+	case NAND_CMD_PARAM:
+	case NAND_CMD_READID:
+		do_addr = false;
+		acycle = NFCADDR_CMD_ACYCLE_1;
+		if (column != -1)
+			addr1234 = column;
+		break;
+	case NAND_CMD_RNDOUT:
+		cmd2 = NAND_CMD_RNDOUTSTART << NFCADDR_CMD_CMD2_BIT_POS;
+		vcmd2 = NFCADDR_CMD_VCMD2;
+		break;
+	case NAND_CMD_READ0:
+	case NAND_CMD_READOOB:
+		if (command == NAND_CMD_READOOB) {
+			column += mtd->writesize;
+			command = NAND_CMD_READ0; /* only READ0 is valid */
+			cmd1 = command << NFCADDR_CMD_CMD1_BIT_POS;
+		}
+
+		cmd2 = NAND_CMD_READSTART << NFCADDR_CMD_CMD2_BIT_POS;
+		vcmd2 = NFCADDR_CMD_VCMD2;
+		break;
+	/* For prgramming command, the cmd need set to write enable */
+	case NAND_CMD_PAGEPROG:
+	case NAND_CMD_SEQIN:
+	case NAND_CMD_RNDIN:
+		nfcwr = NFCADDR_CMD_NFCWR;
+		break;
+	default:
+		break;
+	}
+
+	if (do_addr)
+		acycle = nfc_make_addr(mtd, column, page_addr, &addr1234,
+				&cycle0);
+
+	nfc_addr_cmd = cmd1 | cmd2 | vcmd2 | acycle | csid | dataen | nfcwr;
+	nfc_send_command(host, nfc_addr_cmd, addr1234, cycle0);
+
+	/*
+	 * Program and erase have their own busy handlers status, sequential
+	 * in, and deplete1 need no delay.
+	 */
+	switch (command) {
+	case NAND_CMD_CACHEDPROG:
+	case NAND_CMD_PAGEPROG:
+	case NAND_CMD_ERASE1:
+	case NAND_CMD_ERASE2:
+	case NAND_CMD_RNDIN:
+	case NAND_CMD_STATUS:
+	case NAND_CMD_RNDOUT:
+	case NAND_CMD_SEQIN:
+	case NAND_CMD_READID:
+		return;
+
+	case NAND_CMD_READ0:
+		/* fall through */
+	default:
+		nfc_wait_interrupt(host, NFC_SR_RB_EDGE);
+	}
+}
+
+static struct platform_driver atmel_nand_nfc_driver;
 /*
  * Probe for the NAND device.
  */
@@ -1457,7 +1762,7 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
 	struct nand_chip *nand_chip;
 	struct resource *mem;
 	struct mtd_part_parser_data ppdata = {};
-	int res;
+	int res, irq;
 
 	/* Allocate memory for the device structure (and zero it) */
 	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
@@ -1466,6 +1771,10 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	res = platform_driver_register(&atmel_nand_nfc_driver);
+	if (res)
+		dev_err(&pdev->dev, "atmel_nand: can't register NFC driver\n");
+
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	host->io_base = devm_ioremap_resource(&pdev->dev, mem);
 	if (IS_ERR(host->io_base)) {
@@ -1494,46 +1803,35 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
 	/* Set address of NAND IO lines */
 	nand_chip->IO_ADDR_R = host->io_base;
 	nand_chip->IO_ADDR_W = host->io_base;
-	nand_chip->cmd_ctrl = atmel_nand_cmd_ctrl;
-
-	if (gpio_is_valid(host->board.rdy_pin)) {
-		res = devm_gpio_request(&pdev->dev,
-				host->board.rdy_pin, "nand_rdy");
-		if (res < 0) {
-			dev_err(&pdev->dev,
-				"can't request rdy gpio %d\n",
-				host->board.rdy_pin);
-			goto err_nand_ioremap;
-		}
 
-		res = gpio_direction_input(host->board.rdy_pin);
-		if (res < 0) {
-			dev_err(&pdev->dev,
-				"can't request input direction rdy gpio %d\n",
-				host->board.rdy_pin);
-			goto err_nand_ioremap;
-		}
+	if (nand_nfc.is_initialized) {
+		/* NFC driver is probed and initialized */
+		host->nfc = &nand_nfc;
 
-		nand_chip->dev_ready = atmel_nand_device_ready;
-	}
+		nand_chip->select_chip = nfc_select_chip;
+		nand_chip->dev_ready = nfc_device_ready;
+		nand_chip->cmdfunc = nfc_nand_command;
 
-	if (gpio_is_valid(host->board.enable_pin)) {
-		res = devm_gpio_request(&pdev->dev,
-				host->board.enable_pin, "nand_enable");
-		if (res < 0) {
-			dev_err(&pdev->dev,
-				"can't request enable gpio %d\n",
-				host->board.enable_pin);
+		/* Initialize the interrupt for NFC */
+		irq = platform_get_irq(pdev, 0);
+		if (irq < 0) {
+			dev_err(host->dev, "Cannot get HSMC irq!\n");
 			goto err_nand_ioremap;
 		}
 
-		res = gpio_direction_output(host->board.enable_pin, 1);
-		if (res < 0) {
-			dev_err(&pdev->dev,
-				"can't request output direction enable gpio %d\n",
-				host->board.enable_pin);
+		res = devm_request_irq(&pdev->dev, irq, hsmc_interrupt,
+				0, "hsmc", host);
+		if (res) {
+			dev_err(&pdev->dev, "Unable to request HSMC irq %d\n",
+				irq);
 			goto err_nand_ioremap;
 		}
+	} else {
+		res = atmel_nand_set_enable_ready_pins(mtd);
+		if (res)
+			goto err_nand_ioremap;
+
+		nand_chip->cmd_ctrl = atmel_nand_cmd_ctrl;
 	}
 
 	nand_chip->ecc.mode = host->board.ecc_mode;
@@ -1637,6 +1935,7 @@ err_no_card:
 	if (host->dma_chan)
 		dma_release_channel(host->dma_chan);
 err_nand_ioremap:
+	platform_driver_unregister(&atmel_nand_nfc_driver);
 	return res;
 }
 
@@ -1661,6 +1960,8 @@ static int __exit atmel_nand_remove(struct platform_device *pdev)
 	if (host->dma_chan)
 		dma_release_channel(host->dma_chan);
 
+	platform_driver_unregister(&atmel_nand_nfc_driver);
+
 	return 0;
 }
 
@@ -1673,6 +1974,50 @@ static const struct of_device_id atmel_nand_dt_ids[] = {
 MODULE_DEVICE_TABLE(of, atmel_nand_dt_ids);
 #endif
 
+static int atmel_nand_nfc_probe(struct platform_device *pdev)
+{
+	struct atmel_nfc *nfc = &nand_nfc;
+	struct resource *nfc_cmd_regs, *nfc_hsmc_regs, *nfc_sram;
+
+	nfc_cmd_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	nfc->base_cmd_regs = devm_ioremap_resource(&pdev->dev, nfc_cmd_regs);
+	if (IS_ERR(nfc->base_cmd_regs))
+		return PTR_ERR(nfc->base_cmd_regs);
+
+	nfc_hsmc_regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	nfc->hsmc_regs = devm_ioremap_resource(&pdev->dev, nfc_hsmc_regs);
+	if (IS_ERR(nfc->hsmc_regs))
+		return PTR_ERR(nfc->hsmc_regs);
+
+	nfc_sram = platform_get_resource(pdev, IORESOURCE_MEM, 2);
+	if (nfc_sram) {
+		nfc->sram_bank0 = devm_ioremap_resource(&pdev->dev, nfc_sram);
+		if (IS_ERR(nfc->sram_bank0))
+			dev_warn(&pdev->dev, "Fail to ioremap the NFC sram with error: %ld. So disable NFC sram.\n",
+					PTR_ERR(nfc->sram_bank0));
+		else
+			nfc->sram_bank0_phys = (dma_addr_t)nfc_sram->start;
+	}
+
+	nfc->is_initialized = true;
+	dev_info(&pdev->dev, "NFC is probed.\n");
+	return 0;
+}
+
+static struct of_device_id atmel_nand_nfc_match[] = {
+	{ .compatible = "atmel,sama5d3-nfc" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver atmel_nand_nfc_driver = {
+	.driver = {
+		.name = "atmel_nand_nfc",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(atmel_nand_nfc_match),
+	},
+	.probe = atmel_nand_nfc_probe,
+};
+
 static struct platform_driver atmel_nand_driver = {
 	.remove		= __exit_p(atmel_nand_remove),
 	.driver		= {

drivers/mtd/nand/atmel_nand_nfc.h

@@ -0,0 +1,98 @@
+/*
+ * Atmel Nand Flash Controller (NFC) - System peripherals regsters.
+ * Based on SAMA5D3 datasheet.
+ *
+ * © Copyright 2013 Atmel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#ifndef ATMEL_NAND_NFC_H
+#define ATMEL_NAND_NFC_H
+
+/*
+ * HSMC NFC registers
+ */
+#define ATMEL_HSMC_NFC_CFG	0x00		/* NFC Configuration Register */
+#define		NFC_CFG_PAGESIZE	(7 << 0)
+#define			NFC_CFG_PAGESIZE_512	(0 << 0)
+#define			NFC_CFG_PAGESIZE_1024	(1 << 0)
+#define			NFC_CFG_PAGESIZE_2048	(2 << 0)
+#define			NFC_CFG_PAGESIZE_4096	(3 << 0)
+#define			NFC_CFG_PAGESIZE_8192	(4 << 0)
+#define		NFC_CFG_WSPARE		(1 << 8)
+#define		NFC_CFG_RSPARE		(1 << 9)
+#define		NFC_CFG_NFC_DTOCYC	(0xf << 16)
+#define		NFC_CFG_NFC_DTOMUL	(0x7 << 20)
+#define		NFC_CFG_NFC_SPARESIZE	(0x7f << 24)
+#define		NFC_CFG_NFC_SPARESIZE_BIT_POS	24
+
+#define ATMEL_HSMC_NFC_CTRL	0x04		/* NFC Control Register */
+#define		NFC_CTRL_ENABLE		(1 << 0)
+#define		NFC_CTRL_DISABLE	(1 << 1)
+
+#define ATMEL_HSMC_NFC_SR	0x08		/* NFC Status Register */
+#define		NFC_SR_XFR_DONE		(1 << 16)
+#define		NFC_SR_CMD_DONE		(1 << 17)
+#define		NFC_SR_RB_EDGE		(1 << 24)
+
+#define ATMEL_HSMC_NFC_IER	0x0c
+#define ATMEL_HSMC_NFC_IDR	0x10
+#define ATMEL_HSMC_NFC_IMR	0x14
+#define ATMEL_HSMC_NFC_CYCLE0	0x18		/* NFC Address Cycle Zero */
+#define		ATMEL_HSMC_NFC_ADDR_CYCLE0	(0xff)
+
+#define ATMEL_HSMC_NFC_BANK	0x1c		/* NFC Bank Register */
+#define		ATMEL_HSMC_NFC_BANK0		(0 << 0)
+#define		ATMEL_HSMC_NFC_BANK1		(1 << 0)
+
+#define nfc_writel(addr, reg, value) \
+	writel((value), (addr) + ATMEL_HSMC_NFC_##reg)
+
+#define nfc_readl(addr, reg) \
+	readl_relaxed((addr) + ATMEL_HSMC_NFC_##reg)
+
+/*
+ * NFC Address Command definitions
+ */
+#define NFCADDR_CMD_CMD1	(0xff << 2)	/* Command for Cycle 1 */
+#define NFCADDR_CMD_CMD1_BIT_POS	2
+#define NFCADDR_CMD_CMD2	(0xff << 10)	/* Command for Cycle 2 */
+#define NFCADDR_CMD_CMD2_BIT_POS	10
+#define NFCADDR_CMD_VCMD2	(0x1 << 18)	/* Valid Cycle 2 Command */
+#define NFCADDR_CMD_ACYCLE	(0x7 << 19)	/* Number of Address required */
+#define		NFCADDR_CMD_ACYCLE_NONE		(0x0 << 19)
+#define		NFCADDR_CMD_ACYCLE_1		(0x1 << 19)
+#define		NFCADDR_CMD_ACYCLE_2		(0x2 << 19)
+#define		NFCADDR_CMD_ACYCLE_3		(0x3 << 19)
+#define		NFCADDR_CMD_ACYCLE_4		(0x4 << 19)
+#define		NFCADDR_CMD_ACYCLE_5		(0x5 << 19)
+#define NFCADDR_CMD_ACYCLE_BIT_POS	19
+#define NFCADDR_CMD_CSID	(0x7 << 22)	/* Chip Select Identifier */
+#define		NFCADDR_CMD_CSID_0		(0x0 << 22)
+#define		NFCADDR_CMD_CSID_1		(0x1 << 22)
+#define		NFCADDR_CMD_CSID_2		(0x2 << 22)
+#define		NFCADDR_CMD_CSID_3		(0x3 << 22)
+#define		NFCADDR_CMD_CSID_4		(0x4 << 22)
+#define		NFCADDR_CMD_CSID_5		(0x5 << 22)
+#define		NFCADDR_CMD_CSID_6		(0x6 << 22)
+#define		NFCADDR_CMD_CSID_7		(0x7 << 22)
+#define NFCADDR_CMD_DATAEN	(0x1 << 25)	/* Data Transfer Enable */
+#define NFCADDR_CMD_DATADIS	(0x0 << 25)	/* Data Transfer Disable */
+#define NFCADDR_CMD_NFCRD	(0x0 << 26)	/* NFC Read Enable */
+#define NFCADDR_CMD_NFCWR	(0x1 << 26)	/* NFC Write Enable */
+#define NFCADDR_CMD_NFCBUSY	(0x1 << 27)	/* NFC Busy */
+
+#define nfc_cmd_addr1234_writel(cmd, addr1234, nfc_base) \
+	writel((addr1234), (cmd) + nfc_base)
+
+#define nfc_cmd_readl(bitstatus, nfc_base) \
+	readl_relaxed((bitstatus) + nfc_base)
+
+#define NFC_TIME_OUT_MS		100
+#define	NFC_SRAM_BANK1_OFFSET	0x1200
+
+#endif