[PATCH v6 1/3] nand: pl353: Add basic driver for arm pl353 smc nand interface

[PATCH v6 1/3] nand: pl353: Add basic driver for arm pl353 smc nand interface

[Punnaiah Choudary Kalluri]

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@xilinx.com>
---
Changes in v6:
 - Fixed the checkpatch.pl reported warnings
 - Using the address cycles information from the onfi param page
   earlier it is hardcoded to 5 in driver
Changes in v5:
 - Configure the nand timing parameters as per the onfi spec
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 |  904 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 912 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 5897d8d..c14a955 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -497,6 +497,13 @@ 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 582bbd05..c68fd7c 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -52,5 +52,6 @@ obj-$(CONFIG_MTD_NAND_XWAY)		+= xway_nand.o
 obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash/
 obj-$(CONFIG_MTD_NAND_SUNXI)		+= sunxi_nand.o
 obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
+obj-$(CONFIG_MTD_NAND_PL353)		+= pl353_nand.o
 
 nand-objs := nand_base.o nand_bbt.o nand_timings.o
diff --git a/drivers/mtd/nand/pl353_nand.c b/drivers/mtd/nand/pl353_nand.c
new file mode 100644
index 0000000..1fe048f
--- /dev/null
+++ b/drivers/mtd/nand/pl353_nand.c
@@ -0,0 +1,904 @@
+/*
+ * 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
+ * @row_addr_cycles:	Row address cycles
+ * @col_addr_cycles:	Column address cycles
+ */
+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;
+	u8 row_addr_cycles;
+	u8 col_addr_cycles;
+};
+
+/*
+ * 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} }
+};
+
+static unsigned int get_cyc_from_ns(u32 clkrate, u32 ns)
+{
+	unsigned int cycle;
+
+	cycle = NSEC_PER_SEC / clkrate;
+	return DIV_ROUND_CLOSEST(ns, cycle);
+}
+
+/**
+ * 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 - [REPLACEABLE] 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 - [REPLACEABLE] 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)
+{
+
+}
+
+/**
+ * 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;
+	u32 addrcycles;
+
+	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;
+
+	if ((command == NAND_CMD_READ0) && (command == NAND_CMD_SEQIN))
+		addrcycles = xnand->row_addr_cycles + xnand->col_addr_cycles;
+	else if (command == NAND_CMD_ERASE1)
+		addrcycles = xnand->row_addr_cycles;
+	else
+		addrcycles = curr_cmd->addr_cycles;
+
+	cmd_phase_addr = (unsigned long __force)xnand->nand_base        |
+			 (addrcycles << 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;
+			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;
+}
+
+static int pl353_nand_init_timing(struct device *dev, int mode)
+{
+	const struct nand_sdr_timings *time;
+	u32 t_rc, t_wc, t_rea, t_wp, t_clr, t_ar, t_rr;
+	ulong clkrate;
+
+	time = onfi_async_timing_mode_to_sdr_timings(mode);
+	if (IS_ERR(time))
+		return PTR_ERR(time);
+
+	clkrate = pl353_smc_get_clkrate(dev);
+	t_rc  = get_cyc_from_ns(clkrate, time->tRC_min / 1000);
+	t_wc  = get_cyc_from_ns(clkrate, time->tWC_min / 1000);
+	t_rea = get_cyc_from_ns(clkrate, time->tREA_max / 1000);
+	t_wp  = get_cyc_from_ns(clkrate, time->tWP_min / 1000);
+	t_clr = get_cyc_from_ns(clkrate, time->tCLR_min / 1000);
+	t_ar  = get_cyc_from_ns(clkrate, time->tAR_min / 1000);
+	t_rr  = get_cyc_from_ns(clkrate, time->tRR_min / 1000);
+
+	pl353_smc_set_cycles(dev, t_rc, t_wc, t_rea, t_wp, t_clr, t_ar, t_rr);
+
+	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);
+	if (pl353_nand_init_timing(pdev->dev.parent, 0))
+		return -ENOTSUPP;
+	/* 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;
+
+	xnand->row_addr_cycles = nand_chip->onfi_params.addr_cycles & 0xF;
+	xnand->col_addr_cycles =
+				(nand_chip->onfi_params.addr_cycles >> 4) & 0xF;
+
+	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);
+
+	/* TODO: Based on the parameter page info, change the timing mode */
+
+	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,
+		.of_match_table = pl353_nand_of_match,
+	},
+};
+
+module_platform_driver(pl353_nand_driver);
+
+MODULE_AUTHOR("Punnaiah Choudary Kalluri <punnaia@xilinx.com>");
+MODULE_DESCRIPTION("ARM PL353 NAND Flash Driver");
+MODULE_LICENSE("GPL v2");
-- 
1.7.4

Re: [PATCH v6 1/3] nand: pl353: Add basic driver for arm pl353 smc nand interface

[Paul Bolle]

On Mon, 2015-04-13 at 21:42 +0530, Punnaiah Choudary Kalluri wrote:

> --- a/drivers/mtd/nand/Makefile
> +++ b/drivers/mtd/nand/Makefile

> +obj-$(CONFIG_MTD_NAND_PL353)		+= pl353_nand.o

(I think pl353_nand.o can be part of a module. If that's incorrect, you
can stop reading here.) 

> --- /dev/null
> +++ b/drivers/mtd/nand/pl353_nand.c

> + * 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.

This states the license of this driver is GPL v2 or later.

> +MODULE_LICENSE("GPL v2");

And according to include/linux/module.h this states the license is GPL
v2. So either the comment at the top of this file or the license ident
used in the MODULE_LICENSE() macro needs to change.

Thanks,


Paul Bolle

Re: [PATCH v6 1/3] nand: pl353: Add basic driver for arm pl353 smc nand interface

[punnaiah choudary kalluri]

Hi Paul Bolle,

On Tue, Apr 14, 2015 at 12:27 AM, Paul Bolle <pebolle@tiscali.nl> wrote:
> On Mon, 2015-04-13 at 21:42 +0530, Punnaiah Choudary Kalluri wrote:
>
>> --- a/drivers/mtd/nand/Makefile
>> +++ b/drivers/mtd/nand/Makefile
>
>> +obj-$(CONFIG_MTD_NAND_PL353)         += pl353_nand.o
>
> (I think pl353_nand.o can be part of a module. If that's incorrect, you
> can stop reading here.)
>
>> --- /dev/null
>> +++ b/drivers/mtd/nand/pl353_nand.c
>
>> + * 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.
>
> This states the license of this driver is GPL v2 or later.
>
>> +MODULE_LICENSE("GPL v2");
>
> And according to include/linux/module.h this states the license is GPL
> v2. So either the comment at the top of this file or the license ident
> used in the MODULE_LICENSE() macro needs to change.

Thanks for the review. I will change the licence ident to "GPL".

I will wait some time for further functional comments on this driver
before sending the next version
of patches.

Regards,
Punnaiah

>
> Thanks,
>
>
> Paul Bolle
>

Re: [PATCH v6 1/3] nand: pl353: Add basic driver for arm pl353 smc nand interface

[Ben Shelton]

Hi Punnaiah,

On 04/13, Punnaiah Choudary Kalluri wrote:
> 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@xilinx.com>

[...]

> +
> +static int pl353_nand_init_timing(struct device *dev, int mode)
> +{
> +	const struct nand_sdr_timings *time;
> +	u32 t_rc, t_wc, t_rea, t_wp, t_clr, t_ar, t_rr;
> +	ulong clkrate;
> +
> +	time = onfi_async_timing_mode_to_sdr_timings(mode);
> +	if (IS_ERR(time))
> +		return PTR_ERR(time);
> +
> +	clkrate = pl353_smc_get_clkrate(dev);
> +	t_rc  = get_cyc_from_ns(clkrate, time->tRC_min / 1000);
> +	t_wc  = get_cyc_from_ns(clkrate, time->tWC_min / 1000);
> +	t_rea = get_cyc_from_ns(clkrate, time->tREA_max / 1000);
> +	t_wp  = get_cyc_from_ns(clkrate, time->tWP_min / 1000);
> +	t_clr = get_cyc_from_ns(clkrate, time->tCLR_min / 1000);
> +	t_ar  = get_cyc_from_ns(clkrate, time->tAR_min / 1000);
> +	t_rr  = get_cyc_from_ns(clkrate, time->tRR_min / 1000);

I tested this patch set in conjunction with your PL353 SMC patch set.

Our first stage bootloader sets the SMC memclk rate to 166.6 MHz, which leads
this code to calculate a t_rc and t_wc of 17 cycles for ONFI mode 0.  As I
mentioned in my response to your SMC patch, this overflows the 4-bit-wide
register fields in the SMC that hold these values.

Could we somehow set it up so the NAND and SMC drivers work together to adjust
the memclk rate, if necessary, to achieve the desired timings?  Or is there a
better way to handle this?

> +
> +	pl353_smc_set_cycles(dev, t_rc, t_wc, t_rea, t_wp, t_clr, t_ar, t_rr);
> +
> +	return 0;
> +}

Thanks,
Ben

Re: [PATCH v6 1/3] nand: pl353: Add basic driver for arm pl353 smc nand interface

[punnaiah choudary kalluri]

On Tue, Apr 28, 2015 at 9:08 PM, Ben Shelton <ben.shelton@ni.com> wrote:
> Hi Punnaiah,
>
> On 04/13, Punnaiah Choudary Kalluri wrote:
>> 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@xilinx.com>
>
> [...]
>
>> +
>> +static int pl353_nand_init_timing(struct device *dev, int mode)
>> +{
>> +     const struct nand_sdr_timings *time;
>> +     u32 t_rc, t_wc, t_rea, t_wp, t_clr, t_ar, t_rr;
>> +     ulong clkrate;
>> +
>> +     time = onfi_async_timing_mode_to_sdr_timings(mode);
>> +     if (IS_ERR(time))
>> +             return PTR_ERR(time);
>> +
>> +     clkrate = pl353_smc_get_clkrate(dev);
>> +     t_rc  = get_cyc_from_ns(clkrate, time->tRC_min / 1000);
>> +     t_wc  = get_cyc_from_ns(clkrate, time->tWC_min / 1000);
>> +     t_rea = get_cyc_from_ns(clkrate, time->tREA_max / 1000);
>> +     t_wp  = get_cyc_from_ns(clkrate, time->tWP_min / 1000);
>> +     t_clr = get_cyc_from_ns(clkrate, time->tCLR_min / 1000);
>> +     t_ar  = get_cyc_from_ns(clkrate, time->tAR_min / 1000);
>> +     t_rr  = get_cyc_from_ns(clkrate, time->tRR_min / 1000);
>
> I tested this patch set in conjunction with your PL353 SMC patch set.
>
> Our first stage bootloader sets the SMC memclk rate to 166.6 MHz, which leads
> this code to calculate a t_rc and t_wc of 17 cycles for ONFI mode 0.  As I
> mentioned in my response to your SMC patch, this overflows the 4-bit-wide
> register fields in the SMC that hold these values.

The better way is fixing the frequency to correct value to avoid the
overflow conditions.
Even as per ONFI spec, the maximum cycle time for SDR mode is 20 ns and DDR mode
is 10 ns. As you pointed i will update the smc driver with required
boundary checks for the lower
and upper limits.

>
> Could we somehow set it up so the NAND and SMC drivers work together to adjust
> the memclk rate, if necessary, to achieve the desired timings?  Or is there a
> better way to handle this?

Let me check on this. I didn't see the option to control the clock
rate at module level, otherwise
probably we can have DT entry and configure the required frequency
during the probe time.

Regards,
Punnaiah
>
>> +
>> +     pl353_smc_set_cycles(dev, t_rc, t_wc, t_rea, t_wp, t_clr, t_ar, t_rr);
>> +
>> +     return 0;
>> +}
>
> Thanks,
> Ben

[PATCH v6 2/3] nand: pl353: Add software ecc support

[Punnaiah Choudary Kalluri]

Added software ecc support.

Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
---
Changes in v6:
- None
Changes in v5:
- None
Changes in v4:
- Updated the driver to sync with pl353_smc driver APIs
---
 drivers/mtd/nand/pl353_nand.c |  164 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 164 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/nand/pl353_nand.c b/drivers/mtd/nand/pl353_nand.c
index 1fe048f..4f4bf93 100644
--- a/drivers/mtd/nand/pl353_nand.c
+++ b/drivers/mtd/nand/pl353_nand.c
@@ -331,6 +331,71 @@ static int pl353_nand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
 }
 
 /**
+ * pl353_nand_read_page_raw - [Intern] read raw page data without ecc
+ * @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
+ * @page:		Page number to read
+ *
+ * Return:	Always return zero
+ */
+static int pl353_nand_read_page_raw(struct mtd_info *mtd,
+				struct nand_chip *chip,
+				uint8_t *buf, int oob_required, int page)
+{
+	unsigned long data_phase_addr;
+	uint8_t *p;
+
+	chip->read_buf(mtd, buf, mtd->writesize);
+
+	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_page_raw - [Intern] raw 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
+ *
+ * Return:	Always return zero
+ */
+static int pl353_nand_write_page_raw(struct mtd_info *mtd,
+				    struct nand_chip *chip,
+				    const uint8_t *buf, int oob_required)
+{
+	unsigned long data_phase_addr;
+	uint8_t *p;
+
+	chip->write_buf(mtd, buf, mtd->writesize);
+
+	p = chip->oob_poi;
+	chip->write_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_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, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	return 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
@@ -396,6 +461,39 @@ static int pl353_nand_write_page_hwecc(struct mtd_info *mtd,
 }
 
 /**
+ * pl353_nand_write_page_swecc - [REPLACEABLE] software 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
+ *
+ * Return:	Always return zero
+ */
+static int pl353_nand_write_page_swecc(struct mtd_info *mtd,
+				    struct nand_chip *chip, const uint8_t *buf,
+				    int oob_required)
+{
+	int i, eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *ecc_calc = chip->buffers->ecccalc;
+	const uint8_t *p = buf;
+	uint32_t *eccpos = chip->ecc.layout->eccpos;
+
+	/* Software ecc calculation */
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
+		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+	for (i = 0; i < chip->ecc.total; i++)
+		chip->oob_poi[eccpos[i]] = ecc_calc[i];
+
+	chip->ecc.write_page_raw(mtd, chip, buf, 1);
+
+	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
@@ -477,6 +575,52 @@ static int pl353_nand_read_page_hwecc(struct mtd_info *mtd,
 }
 
 /**
+ * pl353_nand_read_page_swecc - [REPLACEABLE] software 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
+ *
+ * Return:	Always return zero
+ */
+static int pl353_nand_read_page_swecc(struct mtd_info *mtd,
+				     struct nand_chip *chip,
+				     uint8_t *buf,  int oob_required, int page)
+{
+	int i, 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;
+
+	chip->ecc.read_page_raw(mtd, chip, buf, page, 1);
+
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
+		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+	for (i = 0; i < chip->ecc.total; i++)
+		ecc_code[i] = chip->oob_poi[eccpos[i]];
+
+	eccsteps = chip->ecc.steps;
+	p = buf;
+
+	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		int stat;
+
+		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
@@ -708,6 +852,8 @@ static int pl353_nand_ecc_init(struct mtd_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;
+	nand_chip->ecc.read_page_raw = pl353_nand_read_page_raw;
+	nand_chip->ecc.write_page_raw = pl353_nand_write_page_raw;
 
 	switch (xnand->ecc_mode) {
 	case NAND_ECC_HW:
@@ -734,6 +880,24 @@ static int pl353_nand_ecc_init(struct mtd_info *mtd)
 			nand_chip->ecc.layout = &nand_oob_64;
 
 		break;
+	case NAND_ECC_SOFT:
+		/*
+		 * The software ECC routines won't work with the
+		 * SMC controller
+		 */
+		nand_chip->ecc.mode = NAND_ECC_HW;
+		nand_chip->ecc.calculate = nand_calculate_ecc;
+		nand_chip->ecc.correct = nand_correct_data;
+		nand_chip->ecc.read_page = pl353_nand_read_page_swecc;
+		nand_chip->ecc.write_page = pl353_nand_write_page_swecc;
+		nand_chip->ecc.size = 256;
+		nand_chip->ecc.bytes = 3;
+		/* Bypass the controller ECC block */
+		pl353_smc_set_ecc_pg_size(mtd->dev.parent, mtd->writesize);
+		pl353_smc_set_ecc_mode(mtd->dev.parent,
+					PL353_SMC_ECCMODE_BYPASS);
+
+		break;
 	default:
 		return -ENOTSUPP;
 	}
-- 
1.7.4

[PATCH v6 3/3] Documentation: nand: pl353: Add documentation for controller and driver

[Punnaiah Choudary Kalluri]

Added notes about the controller and driver

Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
---
Changes in v6:
- None
Changes in v5:
- Fixed the review comments
Changes in v4:
- None
---
 Documentation/mtd/nand/pl353-nand.txt |   92 +++++++++++++++++++++++++++++++++
 1 files changed, 92 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/mtd/nand/pl353-nand.txt

diff --git a/Documentation/mtd/nand/pl353-nand.txt b/Documentation/mtd/nand/pl353-nand.txt
new file mode 100644
index 0000000..d91ad62
--- /dev/null
+++ b/Documentation/mtd/nand/pl353-nand.txt
@@ -0,0 +1,92 @@
+This documents provides some notes about the ARM pl353 smc controller used in
+Zynq SOC and confined to NAND specific details.
+
+Overview of the controller
+==========================
+	The SMC (PL353) supports two memory interfaces:
+	Interface 0 type SRAM.
+	Interface 1 type NAND.
+	This configuration supports the following configurable options:
+	   . 32-bit or 64-bit AXI data width
+	   . 8-bit, 16-bit, or 32-bit memory data width for interface 0
+	   . 8-bit, or 16-bit memory data width for interface 1
+	   . 1-4 chip selects on each interface
+	   . SLC ECC block for interface 1
+
+For more information, refer the below link for TRM
+http://infocenter.arm.com/help/topic/com.arm.doc.ddi0380g/
+DDI0380G_smc_pl350_series_r2p1_trm.pdf
+
+NAND memory accesses
+====================
+	. Two phase NAND accesses
+	. NAND command phase transfers
+	. NAND data phase transfers
+
+Two phase NAND accesses
+	The SMC defines two phases of commands when transferring data to or from
+NAND flash.
+
+Command phase
+	Commands and optional address information are written to the NAND flash.
+The command and address can be associated with either a data phase operation to
+write to or read from the array, or a status/ID register transfer.
+
+Data phase
+ Data is either written to or read from the NAND flash. This data can be either
+data transferred to or from the array, or status/ID register information.
+
+NAND AXI address setup
+       AXI address      Command phase      Data phase
+	[31:24]         Chip address       Chip address
+	[23]            NoOfAddCycles_2    Reserved
+	[22]            NoOfAddCycles_1    Reserved
+	[21]            NoOfAddCycles_0    ClearCS
+	[20]            End command valid  End command valid
+	[19]            0                  1
+	[18:11]         End command        End command
+	[10:3]          Start command      [10] ECC Last
+					   [9:3] Reserved
+	[2:0]           Reserved           Reserved
+
+ECC
+===
+    It operates on a number of 512 byte blocks of NAND memory and can be
+programmed to store the ECC codes after the data in memory. For writes,
+the ECC is written to the spare area of the page. For reads, the result of
+a block ECC check are made available to the device driver.
+
+------------------------------------------------------------------------
+|               n * 512 blocks                  | extra  | ecc    |     |
+|                                               | block  | codes  |     |
+------------------------------------------------------------------------
+
+The ECC calculation uses a simple Hamming code, using 1-bit correction 2-bit
+detection. It starts when a valid read or write command with a 512 byte aligned
+address is detected on the memory interface.
+
+Driver details
+==============
+	The NAND driver has dependency with the pl353_smc memory controller
+driver for intializing the nand timing parameters, bus width, ECC modes,
+control and status information.
+
+Since the controller expects that the chipselect bit should be cleared for the
+last data transfer i.e last 4 data bytes, the existing nandbase page
+read/write routines for soft ecc and ecc none modes will not work. So, inorder
+to make this driver work, it always updates the ecc mode as HW ECC and
+implemented the page read/write functions for supporting the SW ECC.
+
+HW ECC mode:
+	Upto 2K page size is supported and beyond that it retuns
+-ENOSUPPORT error. If the flsh has ONDIE ecc controller then the
+priority has given to the ONDIE ecc controller. Also the current
+implementation has support for upto 64 byte oob area
+
+SW ECC mode:
+	It supports all the pgae sizes. But since, zynq soc bootrom uses
+HW ECC for the devices that have pgae size <=2K so, to avoid any ecc related
+issues during boot, prefer HW ECC over SW ECC.
+
+For devicetree binding information please refer the below dt binding file
+Documentation/devicetree/bindings/memory-controllers/pl353-smc.txt
-- 
1.7.4