Message-ID: <3e94eb55-c3dc-4d9d-a6fd-fe0171bcfb5d@BN1AFFO11FD028.protection.gbl>
Date:	Mon, 28 Jul 2014 21:01:37 +0530
From:	Punnaiah Choudary Kalluri <punnaiah.choudary.kalluri@...inx.com>
To:	<robh+dt@...nel.org>, <pawel.moll@....com>, <mark.rutland@....com>,
	<ijc+devicetree@...lion.org.uk>, <galak@...eaurora.org>,
	<rob@...dley.net>, <michal.simek@...inx.com>,
	<grant.likely@...aro.org>, <gregkh@...uxfoundation.org>,
	<jason@...edaemon.net>, <ezequiel.garcia@...e-electrons.com>,
	<arnd@...db.de>, <dwmw2@...radead.org>,
	<computersforpeace@...il.com>, <artem.bityutskiy@...ux.intel.com>,
	<pekon@...com>, <jussi.kivilinna@....fi>, <acourbot@...dia.com>,
	<ivan.khoronzhuk@...com>, <joern@...fs.org>
CC:	<devicetree@...r.kernel.org>, <linux-doc@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <linux-mtd@...ts.infradead.org>,
	<kpc528@...il.com>, <kalluripunnaiahchoudary@...il.com>,
	<anirudh@...inx.com>, <svemula@...inx.com>,
	Punnaiah Choudary Kalluri <punnaia@...inx.com>
Subject: [PATCH RFC v4 1/4] nand: pl353: Add basic driver for arm pl353 smc nand interface

Add driver for arm pl353 static memory controller nand interface with
HW ECC support. This controller is used in xilinx zynq soc for interfacing
the nand flash memory.

Signed-off-by: Punnaiah Choudary Kalluri <punnaia@...inx.com>
---
Changes in v4:
 - Updated the driver to sync with pl353_smc driver APIs
Changes in v3:
 - implemented the proper error codes
 - further breakdown this patch to multiple sets
 - added the controller and driver details to Documentation section
 - updated the licenece to GPLv2
 - reorganized the pl353_nand_ecc_init function
Changes in v2:
 - use "depends on" rather than "select" option in kconfig
 - remove unused variable parts
 - remove dummy helper and use writel_relaxed directly
---
 drivers/mtd/nand/Kconfig      |    7 +
 drivers/mtd/nand/Makefile     |    1 +
 drivers/mtd/nand/pl353_nand.c |  857 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 865 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mtd/nand/pl353_nand.c

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index f1cf503..a3462e6 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -492,6 +492,13 @@ config MTD_NAND_NUC900
 	  This enables the driver for the NAND Flash on evaluation board based
 	  on w90p910 / NUC9xx.
 
+config MTD_NAND_PL353
+	tristate "ARM Pl353 NAND flash driver"
+	depends on MTD_NAND && ARM
+	depends on PL353_SMC
+	help
+	  This enables access to the NAND flash device on PL353 SMC controller.
+
 config MTD_NAND_JZ4740
 	tristate "Support for JZ4740 SoC NAND controller"
 	depends on MACH_JZ4740
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 542b568..a4c2679 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -49,5 +49,6 @@ obj-$(CONFIG_MTD_NAND_JZ4740)		+= jz4740_nand.o
 obj-$(CONFIG_MTD_NAND_GPMI_NAND)	+= gpmi-nand/
 obj-$(CONFIG_MTD_NAND_XWAY)		+= xway_nand.o
 obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash/
+obj-$(CONFIG_MTD_NAND_PL353)		+= pl353_nand.o
 
 nand-objs := nand_base.o nand_bbt.o
diff --git a/drivers/mtd/nand/pl353_nand.c b/drivers/mtd/nand/pl353_nand.c
new file mode 100644
index 0000000..f97f428
--- /dev/null
+++ b/drivers/mtd/nand/pl353_nand.c
@@ -0,0 +1,857 @@
+/*
+ * ARM PL353 NAND Flash Controller Driver
+ *
+ * Copyright (C) 2009 - 2014 Xilinx, Inc.
+ *
+ * This driver is based on plat_nand.c and mxc_nand.c drivers
+ *
+ * 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; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/memory/pl353-smc.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_mtd.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define PL353_NAND_DRIVER_NAME "pl353-nand"
+
+/* NAND flash driver defines */
+#define PL353_NAND_CMD_PHASE	1	/* End command valid in command phase */
+#define PL353_NAND_DATA_PHASE	2	/* End command valid in data phase */
+#define PL353_NAND_ECC_SIZE	512	/* Size of data for ECC operation */
+
+/* Flash memory controller operating parameters */
+
+#define PL353_NAND_ECC_CONFIG	(BIT(4)  |	/* ECC read at end of page */ \
+				 (0 << 5))	/* No Jumping */
+
+/* AXI Address definitions */
+#define START_CMD_SHIFT		3
+#define END_CMD_SHIFT		11
+#define END_CMD_VALID_SHIFT	20
+#define ADDR_CYCLES_SHIFT	21
+#define CLEAR_CS_SHIFT		21
+#define ECC_LAST_SHIFT		10
+#define COMMAND_PHASE		(0 << 19)
+#define DATA_PHASE		BIT(19)
+
+#define PL353_NAND_ECC_LAST	BIT(ECC_LAST_SHIFT)	/* Set ECC_Last */
+#define PL353_NAND_CLEAR_CS	BIT(CLEAR_CS_SHIFT)	/* Clear chip select */
+
+#define ONDIE_ECC_FEATURE_ADDR	0x90
+#define PL353_NAND_ECC_BUSY_TIMEOUT	(1 * HZ)
+#define PL353_NAND_DEV_BUSY_TIMEOUT	(1 * HZ)
+#define PL353_NAND_LAST_TRANSFER_LENGTH	4
+
+/**
+ * struct pl353_nand_command_format - Defines NAND flash command format
+ * @start_cmd:		First cycle command (Start command)
+ * @end_cmd:		Second cycle command (Last command)
+ * @addr_cycles:	Number of address cycles required to send the address
+ * @end_cmd_valid:	The second cycle command is valid for cmd or data phase
+ */
+struct pl353_nand_command_format {
+	int start_cmd;
+	int end_cmd;
+	u8 addr_cycles;
+	u8 end_cmd_valid;
+};
+
+/**
+ * struct pl353_nand_info - Defines the NAND flash driver instance
+ * @chip:		NAND chip information structure
+ * @mtd:		MTD information structure
+ * @nand_base:		Virtual address of the NAND flash device
+ * @end_cmd_pending:	End command is pending
+ * @end_cmd:		End command
+ * @ecc_mode:		ECC mode
+ */
+struct pl353_nand_info {
+	struct nand_chip chip;
+	struct mtd_info mtd;
+	void __iomem *nand_base;
+	unsigned long end_cmd_pending;
+	unsigned long end_cmd;
+	int ecc_mode;
+};
+
+/*
+ * The NAND flash operations command format
+ */
+static const struct pl353_nand_command_format pl353_nand_commands[] = {
+	{NAND_CMD_READ0, NAND_CMD_READSTART, 5, PL353_NAND_CMD_PHASE},
+	{NAND_CMD_RNDOUT, NAND_CMD_RNDOUTSTART, 2, PL353_NAND_CMD_PHASE},
+	{NAND_CMD_READID, NAND_CMD_NONE, 1, NAND_CMD_NONE},
+	{NAND_CMD_STATUS, NAND_CMD_NONE, 0, NAND_CMD_NONE},
+	{NAND_CMD_SEQIN, NAND_CMD_PAGEPROG, 5, PL353_NAND_DATA_PHASE},
+	{NAND_CMD_RNDIN, NAND_CMD_NONE, 2, NAND_CMD_NONE},
+	{NAND_CMD_ERASE1, NAND_CMD_ERASE2, 3, PL353_NAND_CMD_PHASE},
+	{NAND_CMD_RESET, NAND_CMD_NONE, 0, NAND_CMD_NONE},
+	{NAND_CMD_PARAM, NAND_CMD_NONE, 1, NAND_CMD_NONE},
+	{NAND_CMD_GET_FEATURES, NAND_CMD_NONE, 1, NAND_CMD_NONE},
+	{NAND_CMD_SET_FEATURES, NAND_CMD_NONE, 1, NAND_CMD_NONE},
+	{NAND_CMD_NONE, NAND_CMD_NONE, 0, 0},
+	/* Add all the flash commands supported by the flash device and Linux */
+	/*
+	 * The cache program command is not supported by driver because driver
+	 * cant differentiate between page program and cached page program from
+	 * start command, these commands can be differentiated through end
+	 * command, which doesn't fit in to the driver design. The cache program
+	 * command is not supported by NAND subsystem also, look at 1612 line
+	 * number (in nand_write_page function) of nand_base.c file.
+	 * {NAND_CMD_SEQIN, NAND_CMD_CACHEDPROG, 5, PL353_NAND_YES},
+	 */
+};
+
+/* Define default oob placement schemes for large and small page devices */
+static struct nand_ecclayout nand_oob_16 = {
+	.eccbytes = 3,
+	.eccpos = {0, 1, 2},
+	.oobfree = {
+		{.offset = 8,
+		 . length = 8} }
+};
+
+static struct nand_ecclayout nand_oob_64 = {
+	.eccbytes = 12,
+	.eccpos = {
+		   52, 53, 54, 55, 56, 57,
+		   58, 59, 60, 61, 62, 63},
+	.oobfree = {
+		{.offset = 2,
+		 .length = 50} }
+};
+
+/**
+ * pl353_nand_calculate_hwecc - Calculate Hardware ECC
+ * @mtd:	Pointer to the mtd_info structure
+ * @data:	Pointer to the page data
+ * @ecc_code:	Pointer to the ECC buffer where ECC data needs to be stored
+ *
+ * This function retrieves the Hardware ECC data from the controller and returns
+ * ECC data back to the MTD subsystem.
+ *
+ * Return:	0 on success or error value on failure
+ */
+static int pl353_nand_calculate_hwecc(struct mtd_info *mtd,
+				const u8 *data, u8 *ecc_code)
+{
+	u32 ecc_value, ecc_status;
+	u8 ecc_reg, ecc_byte;
+	unsigned long timeout = jiffies + PL353_NAND_ECC_BUSY_TIMEOUT;
+
+	/* Wait till the ECC operation is complete or timeout */
+	do {
+		if (pl353_smc_ecc_is_busy(mtd->dev.parent))
+			cpu_relax();
+		else
+			break;
+	} while (!time_after_eq(jiffies, timeout));
+
+	if (time_after_eq(jiffies, timeout)) {
+		pr_err("%s timed out\n", __func__);
+		return -ETIMEDOUT;
+	}
+
+	for (ecc_reg = 0; ecc_reg < 4; ecc_reg++) {
+		/* Read ECC value for each block */
+		ecc_value = pl353_smc_get_ecc_val(mtd->dev.parent, ecc_reg);
+		ecc_status = (ecc_value >> 24) & 0xFF;
+		/* ECC value valid */
+		if (ecc_status & 0x40) {
+			for (ecc_byte = 0; ecc_byte < 3; ecc_byte++) {
+				/* Copy ECC bytes to MTD buffer */
+				*ecc_code = ecc_value & 0xFF;
+				ecc_value = ecc_value >> 8;
+				ecc_code++;
+			}
+		} else {
+			pr_warn("%s status failed\n", __func__);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+/**
+ * onehot - onehot function
+ * @value:	Value to check for onehot
+ *
+ * This function checks whether a value is onehot or not.
+ * onehot is if and only if onebit is set.
+ *
+ * Return:	1 if it is onehot else 0
+ */
+static int onehot(unsigned short value)
+{
+	return (value & (value - 1)) == 0;
+}
+
+/**
+ * pl353_nand_correct_data - ECC correction function
+ * @mtd:	Pointer to the mtd_info structure
+ * @buf:	Pointer to the page data
+ * @read_ecc:	Pointer to the ECC value read from spare data area
+ * @calc_ecc:	Pointer to the calculated ECC value
+ *
+ * This function corrects the ECC single bit errors & detects 2-bit errors.
+ *
+ * Return:	0 if no ECC errors found
+ *		1 if single bit error found and corrected.
+ *		-1 if multiple ECC errors found.
+ */
+static int pl353_nand_correct_data(struct mtd_info *mtd, unsigned char *buf,
+				unsigned char *read_ecc,
+				unsigned char *calc_ecc)
+{
+	unsigned char bit_addr;
+	unsigned int byte_addr;
+	unsigned short ecc_odd, ecc_even, read_ecc_lower, read_ecc_upper;
+	unsigned short calc_ecc_lower, calc_ecc_upper;
+
+	read_ecc_lower = (read_ecc[0] | (read_ecc[1] << 8)) & 0xfff;
+	read_ecc_upper = ((read_ecc[1] >> 4) | (read_ecc[2] << 4)) & 0xfff;
+
+	calc_ecc_lower = (calc_ecc[0] | (calc_ecc[1] << 8)) & 0xfff;
+	calc_ecc_upper = ((calc_ecc[1] >> 4) | (calc_ecc[2] << 4)) & 0xfff;
+
+	ecc_odd = read_ecc_lower ^ calc_ecc_lower;
+	ecc_even = read_ecc_upper ^ calc_ecc_upper;
+
+	if ((ecc_odd == 0) && (ecc_even == 0))
+		return 0;       /* no error */
+
+	if (ecc_odd == (~ecc_even & 0xfff)) {
+		/* bits [11:3] of error code is byte offset */
+		byte_addr = (ecc_odd >> 3) & 0x1ff;
+		/* bits [2:0] of error code is bit offset */
+		bit_addr = ecc_odd & 0x7;
+		/* Toggling error bit */
+		buf[byte_addr] ^= (1 << bit_addr);
+		return 1;
+	}
+
+	if (onehot(ecc_odd | ecc_even) == 1)
+		return 1; /* one error in parity */
+
+	return -EBADMSG; /* Uncorrectable error */
+}
+
+/**
+ * pl353_nand_read_oob - [REPLACABLE] the most common OOB data read function
+ * @mtd:	Pointer to the mtd info structure
+ * @chip:	Pointer to the NAND chip info structure
+ * @page:	Page number to read
+ *
+ * Return:	Always return zero
+ */
+static int pl353_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
+			    int page)
+{
+	unsigned long data_phase_addr;
+	uint8_t *p;
+
+	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
+
+	p = chip->oob_poi;
+	chip->read_buf(mtd, p,
+			(mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH));
+	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	data_phase_addr = (unsigned long __force)chip->IO_ADDR_R;
+	data_phase_addr |= PL353_NAND_CLEAR_CS;
+	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
+	chip->read_buf(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	return 0;
+}
+
+/**
+ * pl353_nand_write_oob - [REPLACABLE] the most common OOB data write function
+ * @mtd:	Pointer to the mtd info structure
+ * @chip:	Pointer to the NAND chip info structure
+ * @page:	Page number to write
+ *
+ * Return:	Zero on success and EIO on failure
+ */
+static int pl353_nand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
+			     int page)
+{
+	int status = 0;
+	const uint8_t *buf = chip->oob_poi;
+	unsigned long data_phase_addr;
+
+	chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page);
+
+	chip->write_buf(mtd, buf,
+			(mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH));
+	buf += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	data_phase_addr = (unsigned long __force)chip->IO_ADDR_W;
+	data_phase_addr |= PL353_NAND_CLEAR_CS;
+	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
+	chip->IO_ADDR_W = (void __iomem * __force)data_phase_addr;
+	chip->write_buf(mtd, buf, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	/* Send command to program the OOB data */
+	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+	status = chip->waitfunc(mtd, chip);
+
+	return status & NAND_STATUS_FAIL ? -EIO : 0;
+}
+
+/**
+ * nand_write_page_hwecc - Hardware ECC based page write function
+ * @mtd:		Pointer to the mtd info structure
+ * @chip:		Pointer to the NAND chip info structure
+ * @buf:		Pointer to the data buffer
+ * @oob_required:	Caller requires OOB data read to chip->oob_poi
+ *
+ * This functions writes data and hardware generated ECC values in to the page.
+ *
+ * Return:	Zero on success and error on failure.
+ */
+static int pl353_nand_write_page_hwecc(struct mtd_info *mtd,
+				    struct nand_chip *chip, const uint8_t *buf,
+				    int oob_required)
+{
+	int i, status, eccsize = chip->ecc.size;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *ecc_calc = chip->buffers->ecccalc;
+	const uint8_t *p = buf;
+	uint32_t *eccpos = chip->ecc.layout->eccpos;
+	unsigned long data_phase_addr;
+	uint8_t *oob_ptr;
+
+	for ( ; (eccsteps - 1); eccsteps--) {
+		chip->write_buf(mtd, p, eccsize);
+		p += eccsize;
+	}
+	chip->write_buf(mtd, p, (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
+	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	/* Set ECC Last bit to 1 */
+	data_phase_addr = (unsigned long __force)chip->IO_ADDR_W;
+	data_phase_addr |= PL353_NAND_ECC_LAST;
+	chip->IO_ADDR_W = (void __iomem * __force)data_phase_addr;
+	chip->write_buf(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	/* Wait for ECC to be calculated and read the error values */
+	p = buf;
+	status = chip->ecc.calculate(mtd, p, &ecc_calc[0]);
+	if (status)
+		return status;
+
+	for (i = 0; i < chip->ecc.total; i++)
+		chip->oob_poi[eccpos[i]] = ~(ecc_calc[i]);
+
+	/* Clear ECC last bit */
+	data_phase_addr = (unsigned long __force)chip->IO_ADDR_W;
+	data_phase_addr &= ~PL353_NAND_ECC_LAST;
+	chip->IO_ADDR_W = (void __iomem * __force)data_phase_addr;
+
+	/* Write the spare area with ECC bytes */
+	oob_ptr = chip->oob_poi;
+	chip->write_buf(mtd, oob_ptr,
+			(mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH));
+
+	data_phase_addr = (unsigned long __force)chip->IO_ADDR_W;
+	data_phase_addr |= PL353_NAND_CLEAR_CS;
+	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
+	chip->IO_ADDR_W = (void __iomem * __force)data_phase_addr;
+	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+	chip->write_buf(mtd, oob_ptr, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	return 0;
+}
+
+/**
+ * pl353_nand_read_page_hwecc - Hardware ECC based page read function
+ * @mtd:		Pointer to the mtd info structure
+ * @chip:		Pointer to the NAND chip info structure
+ * @buf:		Pointer to the buffer to store read data
+ * @oob_required:	Caller requires OOB data read to chip->oob_poi
+ * @page:		Page number to read
+ *
+ * This functions reads data and checks the data integrity by comparing hardware
+ * generated ECC values and read ECC values from spare area.
+ *
+ * Return:	0 always and updates ECC operation status in to MTD structure
+ */
+static int pl353_nand_read_page_hwecc(struct mtd_info *mtd,
+				     struct nand_chip *chip,
+				     uint8_t *buf, int oob_required, int page)
+{
+	int i, stat, eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *p = buf;
+	uint8_t *ecc_calc = chip->buffers->ecccalc;
+	uint8_t *ecc_code = chip->buffers->ecccode;
+	uint32_t *eccpos = chip->ecc.layout->eccpos;
+	unsigned long data_phase_addr;
+	uint8_t *oob_ptr;
+
+	for ( ; (eccsteps - 1); eccsteps--) {
+		chip->read_buf(mtd, p, eccsize);
+		p += eccsize;
+	}
+	chip->read_buf(mtd, p, (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
+	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	/* Set ECC Last bit to 1 */
+	data_phase_addr = (unsigned long __force)chip->IO_ADDR_R;
+	data_phase_addr |= PL353_NAND_ECC_LAST;
+	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
+	chip->read_buf(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	/* Read the calculated ECC value */
+	p = buf;
+	stat = chip->ecc.calculate(mtd, p, &ecc_calc[0]);
+	if (stat < 0)
+		return stat;
+
+	/* Clear ECC last bit */
+	data_phase_addr = (unsigned long __force)chip->IO_ADDR_R;
+	data_phase_addr &= ~PL353_NAND_ECC_LAST;
+	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
+
+	/* Read the stored ECC value */
+	oob_ptr = chip->oob_poi;
+	chip->read_buf(mtd, oob_ptr,
+			(mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH));
+
+	/* de-assert chip select */
+	data_phase_addr = (unsigned long __force)chip->IO_ADDR_R;
+	data_phase_addr |= PL353_NAND_CLEAR_CS;
+	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
+
+	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+	chip->read_buf(mtd, oob_ptr, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	for (i = 0; i < chip->ecc.total; i++)
+		ecc_code[i] = ~(chip->oob_poi[eccpos[i]]);
+
+	eccsteps = chip->ecc.steps;
+	p = buf;
+
+	/* Check ECC error for all blocks and correct if it is correctable */
+	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
+		if (stat < 0)
+			mtd->ecc_stats.failed++;
+		else
+			mtd->ecc_stats.corrected += stat;
+	}
+	return 0;
+}
+
+/**
+ * pl353_nand_select_chip - Select the flash device
+ * @mtd:	Pointer to the mtd info structure
+ * @chip:	Pointer to the NAND chip info structure
+ *
+ * This function is empty as the NAND controller handles chip select line
+ * internally based on the chip address passed in command and data phase.
+ */
+static void pl353_nand_select_chip(struct mtd_info *mtd, int chip)
+{
+	return;
+}
+
+/**
+ * pl353_nand_cmd_function - Send command to NAND device
+ * @mtd:	Pointer to the mtd_info structure
+ * @command:	The command to be sent to the flash device
+ * @column:	The column address for this command, -1 if none
+ * @page_addr:	The page address for this command, -1 if none
+ */
+static void pl353_nand_cmd_function(struct mtd_info *mtd, unsigned int command,
+				 int column, int page_addr)
+{
+	struct nand_chip *chip = mtd->priv;
+	const struct pl353_nand_command_format *curr_cmd = NULL;
+	struct pl353_nand_info *xnand =
+		container_of(mtd, struct pl353_nand_info, mtd);
+	void __iomem *cmd_addr;
+	unsigned long cmd_data = 0, end_cmd_valid = 0;
+	unsigned long cmd_phase_addr, data_phase_addr, end_cmd, i;
+	unsigned long timeout = jiffies + PL353_NAND_DEV_BUSY_TIMEOUT;
+
+	if (xnand->end_cmd_pending) {
+		/*
+		 * Check for end command if this command request is same as the
+		 * pending command then return
+		 */
+		if (xnand->end_cmd == command) {
+			xnand->end_cmd = 0;
+			xnand->end_cmd_pending = 0;
+			return;
+		}
+	}
+
+	/* Emulate NAND_CMD_READOOB for large page device */
+	if ((mtd->writesize > PL353_NAND_ECC_SIZE) &&
+	    (command == NAND_CMD_READOOB)) {
+		column += mtd->writesize;
+		command = NAND_CMD_READ0;
+	}
+
+	/* Get the command format */
+	for (i = 0; (pl353_nand_commands[i].start_cmd != NAND_CMD_NONE ||
+		     pl353_nand_commands[i].end_cmd != NAND_CMD_NONE); i++)
+		if (command == pl353_nand_commands[i].start_cmd)
+			curr_cmd = &pl353_nand_commands[i];
+
+	if (curr_cmd == NULL)
+		return;
+
+	/* Clear interrupt */
+	pl353_smc_clr_nand_int(mtd->dev.parent);
+
+	/* Get the command phase address */
+	if (curr_cmd->end_cmd_valid == PL353_NAND_CMD_PHASE)
+		end_cmd_valid = 1;
+
+	if (curr_cmd->end_cmd == NAND_CMD_NONE)
+		end_cmd = 0x0;
+	else
+		end_cmd = curr_cmd->end_cmd;
+
+	cmd_phase_addr = (unsigned long __force)xnand->nand_base        |
+			 (curr_cmd->addr_cycles << ADDR_CYCLES_SHIFT)    |
+			 (end_cmd_valid << END_CMD_VALID_SHIFT)          |
+			 (COMMAND_PHASE)                                 |
+			 (end_cmd << END_CMD_SHIFT)                      |
+			 (curr_cmd->start_cmd << START_CMD_SHIFT);
+
+	cmd_addr = (void __iomem * __force)cmd_phase_addr;
+
+	/* Get the data phase address */
+	end_cmd_valid = 0;
+
+	data_phase_addr = (unsigned long __force)xnand->nand_base       |
+			  (0x0 << CLEAR_CS_SHIFT)                         |
+			  (end_cmd_valid << END_CMD_VALID_SHIFT)          |
+			  (DATA_PHASE)                                    |
+			  (end_cmd << END_CMD_SHIFT)                      |
+			  (0x0 << ECC_LAST_SHIFT);
+
+	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
+	chip->IO_ADDR_W = chip->IO_ADDR_R;
+
+	/* Command phase AXI write */
+	/* Read & Write */
+	if (column != -1 && page_addr != -1) {
+		/* Adjust columns for 16 bit bus width */
+		if (chip->options & NAND_BUSWIDTH_16)
+			column >>= 1;
+		cmd_data = column;
+		if (mtd->writesize > PL353_NAND_ECC_SIZE) {
+			cmd_data |= page_addr << 16;
+			/* Another address cycle for devices > 128MiB */
+			if (chip->chipsize > (128 << 20)) {
+				writel_relaxed(cmd_data, cmd_addr);
+				cmd_data = (page_addr >> 16);
+			}
+		} else {
+			cmd_data |= page_addr << 8;
+		}
+	} else if (page_addr != -1) {
+		/* Erase */
+		cmd_data = page_addr;
+	} else if (column != -1) {
+		/*
+		 * Change read/write column, read id etc
+		 * Adjust columns for 16 bit bus width
+		 */
+		if ((chip->options & NAND_BUSWIDTH_16) &&
+			((command == NAND_CMD_READ0) ||
+			(command == NAND_CMD_SEQIN) ||
+			(command == NAND_CMD_RNDOUT) ||
+			(command == NAND_CMD_RNDIN)))
+				column >>= 1;
+		cmd_data = column;
+	}
+
+	writel_relaxed(cmd_data, cmd_addr);
+
+	if (curr_cmd->end_cmd_valid) {
+		xnand->end_cmd = curr_cmd->end_cmd;
+		xnand->end_cmd_pending = 1;
+	}
+
+	ndelay(100);
+
+	if ((command == NAND_CMD_READ0) ||
+	    (command == NAND_CMD_RESET) ||
+	    (command == NAND_CMD_PARAM) ||
+	    (command == NAND_CMD_GET_FEATURES)) {
+
+		/* Wait till the device is ready or timeout */
+		do {
+			if (chip->dev_ready(mtd))
+				break;
+			else
+				cpu_relax();
+		} while (!time_after_eq(jiffies, timeout));
+
+		if (time_after_eq(jiffies, timeout))
+			pr_err("%s timed out\n", __func__);
+		return;
+	}
+}
+
+/**
+ * pl353_nand_read_buf - read chip data into buffer
+ * @mtd:	Pointer to the mtd info structure
+ * @buf:	Pointer to the buffer to store read data
+ * @len:	Number of bytes to read
+ */
+static void pl353_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	int i;
+	struct nand_chip *chip = mtd->priv;
+	unsigned long *ptr = (unsigned long *)buf;
+
+	len >>= 2;
+	for (i = 0; i < len; i++)
+		ptr[i] = readl(chip->IO_ADDR_R);
+}
+
+/**
+ * pl353_nand_write_buf - write buffer to chip
+ * @mtd:	Pointer to the mtd info structure
+ * @buf:	Pointer to the buffer to store read data
+ * @len:	Number of bytes to write
+ */
+static void pl353_nand_write_buf(struct mtd_info *mtd, const uint8_t *buf,
+				int len)
+{
+	int i;
+	struct nand_chip *chip = mtd->priv;
+	unsigned long *ptr = (unsigned long *)buf;
+
+	len >>= 2;
+
+	for (i = 0; i < len; i++)
+		writel(ptr[i], chip->IO_ADDR_W);
+}
+
+/**
+ * pl353_nand_device_ready - Check device ready/busy line
+ * @mtd:	Pointer to the mtd_info structure
+ *
+ * Return:	0 on busy or 1 on ready state
+ */
+static int pl353_nand_device_ready(struct mtd_info *mtd)
+{
+	if (pl353_smc_get_nand_int_status_raw(mtd->dev.parent)) {
+		pl353_smc_clr_nand_int(mtd->dev.parent);
+		return 1;
+	}
+	return 0;
+}
+
+/**
+ * pl353_nand_ecc_init - Initialize the ecc information as per the ecc mode
+ * @mtd:	Pointer to the mtd_info structure
+ *
+ * This function initializes the ecc block and functional pointers as per the
+ * ecc mode
+ *
+ * Return:	Zero on success and error on failure.
+ */
+static int pl353_nand_ecc_init(struct mtd_info *mtd)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct pl353_nand_info *xnand =
+		container_of(mtd, struct pl353_nand_info, mtd);
+
+	nand_chip->ecc.read_oob = pl353_nand_read_oob;
+	nand_chip->ecc.write_oob = pl353_nand_write_oob;
+	nand_chip->ecc.strength = 1;
+
+	switch (xnand->ecc_mode) {
+	case NAND_ECC_HW:
+		if (mtd->writesize > 2048) {
+			pr_warn("hardware ECC not possible\n");
+			return -ENOTSUPP;
+		}
+
+		nand_chip->ecc.mode = NAND_ECC_HW;
+		nand_chip->ecc.calculate = pl353_nand_calculate_hwecc;
+		nand_chip->ecc.correct = pl353_nand_correct_data;
+		nand_chip->ecc.hwctl = NULL;
+		nand_chip->ecc.read_page = pl353_nand_read_page_hwecc;
+		nand_chip->ecc.size = PL353_NAND_ECC_SIZE;
+		nand_chip->ecc.write_page = pl353_nand_write_page_hwecc;
+		pl353_smc_set_ecc_pg_size(mtd->dev.parent, mtd->writesize);
+		pl353_smc_set_ecc_mode(mtd->dev.parent, PL353_SMC_ECCMODE_APB);
+		/* Hardware ECC generates 3 bytes ECC code for each 512 bytes */
+		nand_chip->ecc.bytes = 3;
+
+		if (mtd->oobsize == 16)
+			nand_chip->ecc.layout = &nand_oob_16;
+		else
+			nand_chip->ecc.layout = &nand_oob_64;
+
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+/**
+ * pl353_nand_probe - Probe method for the NAND driver
+ * @pdev:	Pointer to the platform_device structure
+ *
+ * This function initializes the driver data structures and the hardware.
+ *
+ * Return:	0 on success or error value on failure
+ */
+static int pl353_nand_probe(struct platform_device *pdev)
+{
+	struct pl353_nand_info *xnand;
+	struct mtd_info *mtd;
+	struct nand_chip *nand_chip;
+	struct resource *res;
+	struct mtd_part_parser_data ppdata;
+
+	xnand = devm_kzalloc(&pdev->dev, sizeof(*xnand), GFP_KERNEL);
+	if (!xnand)
+		return -ENOMEM;
+
+	/* Map physical address of NAND flash */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	xnand->nand_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(xnand->nand_base))
+		return PTR_ERR(xnand->nand_base);
+
+	/* Link the private data with the MTD structure */
+	mtd = &xnand->mtd;
+	nand_chip = &xnand->chip;
+
+	nand_chip->priv = xnand;
+	mtd->priv = nand_chip;
+	mtd->dev.parent = pdev->dev.parent;
+	mtd->owner = THIS_MODULE;
+	mtd->name = PL353_NAND_DRIVER_NAME;
+
+	/* Set address of NAND IO lines */
+	nand_chip->IO_ADDR_R = xnand->nand_base;
+	nand_chip->IO_ADDR_W = xnand->nand_base;
+
+	/* Set the driver entry points for MTD */
+	nand_chip->cmdfunc = pl353_nand_cmd_function;
+	nand_chip->dev_ready = pl353_nand_device_ready;
+	nand_chip->select_chip = pl353_nand_select_chip;
+
+	/* If we don't set this delay driver sets 20us by default */
+	nand_chip->chip_delay = 30;
+
+	/* Buffer read/write routines */
+	nand_chip->read_buf = pl353_nand_read_buf;
+	nand_chip->write_buf = pl353_nand_write_buf;
+
+	/* Set the device option and flash width */
+	nand_chip->options = NAND_BUSWIDTH_AUTO;
+	nand_chip->bbt_options = NAND_BBT_USE_FLASH;
+
+	platform_set_drvdata(pdev, xnand);
+
+	/* first scan to find the device and get the page size */
+	if (nand_scan_ident(mtd, 1, NULL)) {
+		dev_err(&pdev->dev, "nand_scan_ident for NAND failed\n");
+		return -ENXIO;
+	}
+
+	xnand->ecc_mode = of_get_nand_ecc_mode(pdev->dev.of_node);
+	if (xnand->ecc_mode < 0)
+		xnand->ecc_mode = NAND_ECC_HW;
+
+	if (pl353_nand_ecc_init(mtd))
+		return -ENOTSUPP;
+
+	if (nand_chip->options & NAND_BUSWIDTH_16)
+		pl353_smc_set_buswidth(pdev->dev.parent,
+					PL353_SMC_MEM_WIDTH_16);
+
+	/* second phase scan */
+	if (nand_scan_tail(mtd)) {
+		dev_err(&pdev->dev, "nand_scan_tail for NAND failed\n");
+		return -ENXIO;
+	}
+
+	ppdata.of_node = pdev->dev.of_node;
+
+	mtd_device_parse_register(&xnand->mtd, NULL, &ppdata, NULL, 0);
+
+	return 0;
+}
+
+/**
+ * pl353_nand_remove - Remove method for the NAND driver
+ * @pdev:	Pointer to the platform_device structure
+ *
+ * This function is called if the driver module is being unloaded. It frees all
+ * resources allocated to the device.
+ *
+ * Return:	0 on success or error value on failure
+ */
+static int pl353_nand_remove(struct platform_device *pdev)
+{
+	struct pl353_nand_info *xnand = platform_get_drvdata(pdev);
+
+	/* Release resources, unregister device */
+	nand_release(&xnand->mtd);
+
+	return 0;
+}
+
+/* Match table for device tree binding */
+static const struct of_device_id pl353_nand_of_match[] = {
+	{ .compatible = "arm,pl353-nand-r2p1" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, pl353_nand_of_match);
+
+/*
+ * pl353_nand_driver - This structure defines the NAND subsystem platform driver
+ */
+static struct platform_driver pl353_nand_driver = {
+	.probe		= pl353_nand_probe,
+	.remove		= pl353_nand_remove,
+	.driver		= {
+		.name	= PL353_NAND_DRIVER_NAME,
+		.owner	= THIS_MODULE,
+		.of_match_table = pl353_nand_of_match,
+	},
+};
+
+module_platform_driver(pl353_nand_driver);
+
+MODULE_AUTHOR("Punnaiah Choudary Kalluri <punnaia@...inx.com>");
+MODULE_ALIAS("platform:" PL353_NAND_DRIVER_NAME);
+MODULE_DESCRIPTION("ARM PL353 NAND Flash Driver");
+MODULE_LICENSE("GPL v2");
-- 
1.7.4


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