mtd: rawnand: Move legacy code to nand_legacy.c

Allows us to move a few hundred lines of deprecated code out of the
core file which is quite big.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
diff --git a/drivers/mtd/nand/raw/nand_legacy.c b/drivers/mtd/nand/raw/nand_legacy.c
new file mode 100644
index 0000000..c5ddc86
--- /dev/null
+++ b/drivers/mtd/nand/raw/nand_legacy.c
@@ -0,0 +1,642 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
+ *		  2002-2006 Thomas Gleixner (tglx@linutronix.de)
+ *
+ *  Credits:
+ *	David Woodhouse for adding multichip support
+ *
+ *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
+ *	rework for 2K page size chips
+ *
+ * This file contains all legacy helpers/code that should be removed
+ * at some point.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/nmi.h>
+
+#include "internals.h"
+
+/**
+ * nand_read_byte - [DEFAULT] read one byte from the chip
+ * @chip: NAND chip object
+ *
+ * Default read function for 8bit buswidth
+ */
+static uint8_t nand_read_byte(struct nand_chip *chip)
+{
+	return readb(chip->legacy.IO_ADDR_R);
+}
+
+/**
+ * nand_read_byte16 - [DEFAULT] read one byte endianness aware from the chip
+ * @chip: NAND chip object
+ *
+ * Default read function for 16bit buswidth with endianness conversion.
+ *
+ */
+static uint8_t nand_read_byte16(struct nand_chip *chip)
+{
+	return (uint8_t) cpu_to_le16(readw(chip->legacy.IO_ADDR_R));
+}
+
+/**
+ * nand_select_chip - [DEFAULT] control CE line
+ * @chip: NAND chip object
+ * @chipnr: chipnumber to select, -1 for deselect
+ *
+ * Default select function for 1 chip devices.
+ */
+static void nand_select_chip(struct nand_chip *chip, int chipnr)
+{
+	switch (chipnr) {
+	case -1:
+		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
+				      0 | NAND_CTRL_CHANGE);
+		break;
+	case 0:
+		break;
+
+	default:
+		BUG();
+	}
+}
+
+/**
+ * nand_write_byte - [DEFAULT] write single byte to chip
+ * @chip: NAND chip object
+ * @byte: value to write
+ *
+ * Default function to write a byte to I/O[7:0]
+ */
+static void nand_write_byte(struct nand_chip *chip, uint8_t byte)
+{
+	chip->legacy.write_buf(chip, &byte, 1);
+}
+
+/**
+ * nand_write_byte16 - [DEFAULT] write single byte to a chip with width 16
+ * @chip: NAND chip object
+ * @byte: value to write
+ *
+ * Default function to write a byte to I/O[7:0] on a 16-bit wide chip.
+ */
+static void nand_write_byte16(struct nand_chip *chip, uint8_t byte)
+{
+	uint16_t word = byte;
+
+	/*
+	 * It's not entirely clear what should happen to I/O[15:8] when writing
+	 * a byte. The ONFi spec (Revision 3.1; 2012-09-19, Section 2.16) reads:
+	 *
+	 *    When the host supports a 16-bit bus width, only data is
+	 *    transferred at the 16-bit width. All address and command line
+	 *    transfers shall use only the lower 8-bits of the data bus. During
+	 *    command transfers, the host may place any value on the upper
+	 *    8-bits of the data bus. During address transfers, the host shall
+	 *    set the upper 8-bits of the data bus to 00h.
+	 *
+	 * One user of the write_byte callback is nand_set_features. The
+	 * four parameters are specified to be written to I/O[7:0], but this is
+	 * neither an address nor a command transfer. Let's assume a 0 on the
+	 * upper I/O lines is OK.
+	 */
+	chip->legacy.write_buf(chip, (uint8_t *)&word, 2);
+}
+
+/**
+ * nand_write_buf - [DEFAULT] write buffer to chip
+ * @chip: NAND chip object
+ * @buf: data buffer
+ * @len: number of bytes to write
+ *
+ * Default write function for 8bit buswidth.
+ */
+static void nand_write_buf(struct nand_chip *chip, const uint8_t *buf, int len)
+{
+	iowrite8_rep(chip->legacy.IO_ADDR_W, buf, len);
+}
+
+/**
+ * nand_read_buf - [DEFAULT] read chip data into buffer
+ * @chip: NAND chip object
+ * @buf: buffer to store date
+ * @len: number of bytes to read
+ *
+ * Default read function for 8bit buswidth.
+ */
+static void nand_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
+{
+	ioread8_rep(chip->legacy.IO_ADDR_R, buf, len);
+}
+
+/**
+ * nand_write_buf16 - [DEFAULT] write buffer to chip
+ * @chip: NAND chip object
+ * @buf: data buffer
+ * @len: number of bytes to write
+ *
+ * Default write function for 16bit buswidth.
+ */
+static void nand_write_buf16(struct nand_chip *chip, const uint8_t *buf,
+			     int len)
+{
+	u16 *p = (u16 *) buf;
+
+	iowrite16_rep(chip->legacy.IO_ADDR_W, p, len >> 1);
+}
+
+/**
+ * nand_read_buf16 - [DEFAULT] read chip data into buffer
+ * @chip: NAND chip object
+ * @buf: buffer to store date
+ * @len: number of bytes to read
+ *
+ * Default read function for 16bit buswidth.
+ */
+static void nand_read_buf16(struct nand_chip *chip, uint8_t *buf, int len)
+{
+	u16 *p = (u16 *) buf;
+
+	ioread16_rep(chip->legacy.IO_ADDR_R, p, len >> 1);
+}
+
+/**
+ * panic_nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
+ * @mtd: MTD device structure
+ * @timeo: Timeout
+ *
+ * Helper function for nand_wait_ready used when needing to wait in interrupt
+ * context.
+ */
+static void panic_nand_wait_ready(struct mtd_info *mtd, unsigned long timeo)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int i;
+
+	/* Wait for the device to get ready */
+	for (i = 0; i < timeo; i++) {
+		if (chip->legacy.dev_ready(chip))
+			break;
+		touch_softlockup_watchdog();
+		mdelay(1);
+	}
+}
+
+/**
+ * nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
+ * @chip: NAND chip object
+ *
+ * Wait for the ready pin after a command, and warn if a timeout occurs.
+ */
+void nand_wait_ready(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	unsigned long timeo = 400;
+
+	if (in_interrupt() || oops_in_progress)
+		return panic_nand_wait_ready(mtd, timeo);
+
+	/* Wait until command is processed or timeout occurs */
+	timeo = jiffies + msecs_to_jiffies(timeo);
+	do {
+		if (chip->legacy.dev_ready(chip))
+			return;
+		cond_resched();
+	} while (time_before(jiffies, timeo));
+
+	if (!chip->legacy.dev_ready(chip))
+		pr_warn_ratelimited("timeout while waiting for chip to become ready\n");
+}
+EXPORT_SYMBOL_GPL(nand_wait_ready);
+
+/**
+ * nand_wait_status_ready - [GENERIC] Wait for the ready status after commands.
+ * @mtd: MTD device structure
+ * @timeo: Timeout in ms
+ *
+ * Wait for status ready (i.e. command done) or timeout.
+ */
+static void nand_wait_status_ready(struct mtd_info *mtd, unsigned long timeo)
+{
+	register struct nand_chip *chip = mtd_to_nand(mtd);
+	int ret;
+
+	timeo = jiffies + msecs_to_jiffies(timeo);
+	do {
+		u8 status;
+
+		ret = nand_read_data_op(chip, &status, sizeof(status), true);
+		if (ret)
+			return;
+
+		if (status & NAND_STATUS_READY)
+			break;
+		touch_softlockup_watchdog();
+	} while (time_before(jiffies, timeo));
+};
+
+/**
+ * nand_command - [DEFAULT] Send command to NAND device
+ * @chip: NAND chip object
+ * @command: the command to be sent
+ * @column: the column address for this command, -1 if none
+ * @page_addr: the page address for this command, -1 if none
+ *
+ * Send command to NAND device. This function is used for small page devices
+ * (512 Bytes per page).
+ */
+static void nand_command(struct nand_chip *chip, unsigned int command,
+			 int column, int page_addr)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
+
+	/* Write out the command to the device */
+	if (command == NAND_CMD_SEQIN) {
+		int readcmd;
+
+		if (column >= mtd->writesize) {
+			/* OOB area */
+			column -= mtd->writesize;
+			readcmd = NAND_CMD_READOOB;
+		} else if (column < 256) {
+			/* First 256 bytes --> READ0 */
+			readcmd = NAND_CMD_READ0;
+		} else {
+			column -= 256;
+			readcmd = NAND_CMD_READ1;
+		}
+		chip->legacy.cmd_ctrl(chip, readcmd, ctrl);
+		ctrl &= ~NAND_CTRL_CHANGE;
+	}
+	if (command != NAND_CMD_NONE)
+		chip->legacy.cmd_ctrl(chip, command, ctrl);
+
+	/* Address cycle, when necessary */
+	ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
+	/* Serially input address */
+	if (column != -1) {
+		/* Adjust columns for 16 bit buswidth */
+		if (chip->options & NAND_BUSWIDTH_16 &&
+				!nand_opcode_8bits(command))
+			column >>= 1;
+		chip->legacy.cmd_ctrl(chip, column, ctrl);
+		ctrl &= ~NAND_CTRL_CHANGE;
+	}
+	if (page_addr != -1) {
+		chip->legacy.cmd_ctrl(chip, page_addr, ctrl);
+		ctrl &= ~NAND_CTRL_CHANGE;
+		chip->legacy.cmd_ctrl(chip, page_addr >> 8, ctrl);
+		if (chip->options & NAND_ROW_ADDR_3)
+			chip->legacy.cmd_ctrl(chip, page_addr >> 16, ctrl);
+	}
+	chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
+			      NAND_NCE | NAND_CTRL_CHANGE);
+
+	/*
+	 * Program and erase have their own busy handlers status and sequential
+	 * in needs no delay
+	 */
+	switch (command) {
+
+	case NAND_CMD_NONE:
+	case NAND_CMD_PAGEPROG:
+	case NAND_CMD_ERASE1:
+	case NAND_CMD_ERASE2:
+	case NAND_CMD_SEQIN:
+	case NAND_CMD_STATUS:
+	case NAND_CMD_READID:
+	case NAND_CMD_SET_FEATURES:
+		return;
+
+	case NAND_CMD_RESET:
+		if (chip->legacy.dev_ready)
+			break;
+		udelay(chip->legacy.chip_delay);
+		chip->legacy.cmd_ctrl(chip, NAND_CMD_STATUS,
+				      NAND_CTRL_CLE | NAND_CTRL_CHANGE);
+		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
+				      NAND_NCE | NAND_CTRL_CHANGE);
+		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
+		nand_wait_status_ready(mtd, 250);
+		return;
+
+		/* This applies to read commands */
+	case NAND_CMD_READ0:
+		/*
+		 * READ0 is sometimes used to exit GET STATUS mode. When this
+		 * is the case no address cycles are requested, and we can use
+		 * this information to detect that we should not wait for the
+		 * device to be ready.
+		 */
+		if (column == -1 && page_addr == -1)
+			return;
+
+	default:
+		/*
+		 * If we don't have access to the busy pin, we apply the given
+		 * command delay
+		 */
+		if (!chip->legacy.dev_ready) {
+			udelay(chip->legacy.chip_delay);
+			return;
+		}
+	}
+	/*
+	 * Apply this short delay always to ensure that we do wait tWB in
+	 * any case on any machine.
+	 */
+	ndelay(100);
+
+	nand_wait_ready(chip);
+}
+
+static void nand_ccs_delay(struct nand_chip *chip)
+{
+	/*
+	 * The controller already takes care of waiting for tCCS when the RNDIN
+	 * or RNDOUT command is sent, return directly.
+	 */
+	if (!(chip->options & NAND_WAIT_TCCS))
+		return;
+
+	/*
+	 * Wait tCCS_min if it is correctly defined, otherwise wait 500ns
+	 * (which should be safe for all NANDs).
+	 */
+	if (chip->setup_data_interface)
+		ndelay(chip->data_interface.timings.sdr.tCCS_min / 1000);
+	else
+		ndelay(500);
+}
+
+/**
+ * nand_command_lp - [DEFAULT] Send command to NAND large page device
+ * @chip: NAND chip object
+ * @command: the command to be sent
+ * @column: the column address for this command, -1 if none
+ * @page_addr: the page address for this command, -1 if none
+ *
+ * Send command to NAND device. This is the version for the new large page
+ * devices. We don't have the separate regions as we have in the small page
+ * devices. We must emulate NAND_CMD_READOOB to keep the code compatible.
+ */
+static void nand_command_lp(struct nand_chip *chip, unsigned int command,
+			    int column, int page_addr)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	/* Emulate NAND_CMD_READOOB */
+	if (command == NAND_CMD_READOOB) {
+		column += mtd->writesize;
+		command = NAND_CMD_READ0;
+	}
+
+	/* Command latch cycle */
+	if (command != NAND_CMD_NONE)
+		chip->legacy.cmd_ctrl(chip, command,
+				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+
+	if (column != -1 || page_addr != -1) {
+		int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE;
+
+		/* Serially input address */
+		if (column != -1) {
+			/* Adjust columns for 16 bit buswidth */
+			if (chip->options & NAND_BUSWIDTH_16 &&
+					!nand_opcode_8bits(command))
+				column >>= 1;
+			chip->legacy.cmd_ctrl(chip, column, ctrl);
+			ctrl &= ~NAND_CTRL_CHANGE;
+
+			/* Only output a single addr cycle for 8bits opcodes. */
+			if (!nand_opcode_8bits(command))
+				chip->legacy.cmd_ctrl(chip, column >> 8, ctrl);
+		}
+		if (page_addr != -1) {
+			chip->legacy.cmd_ctrl(chip, page_addr, ctrl);
+			chip->legacy.cmd_ctrl(chip, page_addr >> 8,
+					     NAND_NCE | NAND_ALE);
+			if (chip->options & NAND_ROW_ADDR_3)
+				chip->legacy.cmd_ctrl(chip, page_addr >> 16,
+						      NAND_NCE | NAND_ALE);
+		}
+	}
+	chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
+			      NAND_NCE | NAND_CTRL_CHANGE);
+
+	/*
+	 * Program and erase have their own busy handlers status, sequential
+	 * in and status need no delay.
+	 */
+	switch (command) {
+
+	case NAND_CMD_NONE:
+	case NAND_CMD_CACHEDPROG:
+	case NAND_CMD_PAGEPROG:
+	case NAND_CMD_ERASE1:
+	case NAND_CMD_ERASE2:
+	case NAND_CMD_SEQIN:
+	case NAND_CMD_STATUS:
+	case NAND_CMD_READID:
+	case NAND_CMD_SET_FEATURES:
+		return;
+
+	case NAND_CMD_RNDIN:
+		nand_ccs_delay(chip);
+		return;
+
+	case NAND_CMD_RESET:
+		if (chip->legacy.dev_ready)
+			break;
+		udelay(chip->legacy.chip_delay);
+		chip->legacy.cmd_ctrl(chip, NAND_CMD_STATUS,
+				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
+				      NAND_NCE | NAND_CTRL_CHANGE);
+		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
+		nand_wait_status_ready(mtd, 250);
+		return;
+
+	case NAND_CMD_RNDOUT:
+		/* No ready / busy check necessary */
+		chip->legacy.cmd_ctrl(chip, NAND_CMD_RNDOUTSTART,
+				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
+				      NAND_NCE | NAND_CTRL_CHANGE);
+
+		nand_ccs_delay(chip);
+		return;
+
+	case NAND_CMD_READ0:
+		/*
+		 * READ0 is sometimes used to exit GET STATUS mode. When this
+		 * is the case no address cycles are requested, and we can use
+		 * this information to detect that READSTART should not be
+		 * issued.
+		 */
+		if (column == -1 && page_addr == -1)
+			return;
+
+		chip->legacy.cmd_ctrl(chip, NAND_CMD_READSTART,
+				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
+				      NAND_NCE | NAND_CTRL_CHANGE);
+
+		/* This applies to read commands */
+	default:
+		/*
+		 * If we don't have access to the busy pin, we apply the given
+		 * command delay.
+		 */
+		if (!chip->legacy.dev_ready) {
+			udelay(chip->legacy.chip_delay);
+			return;
+		}
+	}
+
+	/*
+	 * Apply this short delay always to ensure that we do wait tWB in
+	 * any case on any machine.
+	 */
+	ndelay(100);
+
+	nand_wait_ready(chip);
+}
+
+/**
+ * nand_get_set_features_notsupp - set/get features stub returning -ENOTSUPP
+ * @chip: nand chip info structure
+ * @addr: feature address.
+ * @subfeature_param: the subfeature parameters, a four bytes array.
+ *
+ * Should be used by NAND controller drivers that do not support the SET/GET
+ * FEATURES operations.
+ */
+int nand_get_set_features_notsupp(struct nand_chip *chip, int addr,
+				  u8 *subfeature_param)
+{
+	return -ENOTSUPP;
+}
+EXPORT_SYMBOL(nand_get_set_features_notsupp);
+
+/**
+ * nand_wait - [DEFAULT] wait until the command is done
+ * @mtd: MTD device structure
+ * @chip: NAND chip structure
+ *
+ * Wait for command done. This applies to erase and program only.
+ */
+static int nand_wait(struct nand_chip *chip)
+{
+
+	unsigned long timeo = 400;
+	u8 status;
+	int ret;
+
+	/*
+	 * Apply this short delay always to ensure that we do wait tWB in any
+	 * case on any machine.
+	 */
+	ndelay(100);
+
+	ret = nand_status_op(chip, NULL);
+	if (ret)
+		return ret;
+
+	if (in_interrupt() || oops_in_progress)
+		panic_nand_wait(chip, timeo);
+	else {
+		timeo = jiffies + msecs_to_jiffies(timeo);
+		do {
+			if (chip->legacy.dev_ready) {
+				if (chip->legacy.dev_ready(chip))
+					break;
+			} else {
+				ret = nand_read_data_op(chip, &status,
+							sizeof(status), true);
+				if (ret)
+					return ret;
+
+				if (status & NAND_STATUS_READY)
+					break;
+			}
+			cond_resched();
+		} while (time_before(jiffies, timeo));
+	}
+
+	ret = nand_read_data_op(chip, &status, sizeof(status), true);
+	if (ret)
+		return ret;
+
+	/* This can happen if in case of timeout or buggy dev_ready */
+	WARN_ON(!(status & NAND_STATUS_READY));
+	return status;
+}
+
+void nand_legacy_set_defaults(struct nand_chip *chip)
+{
+	unsigned int busw = chip->options & NAND_BUSWIDTH_16;
+
+	if (chip->exec_op)
+		return;
+
+	/* check for proper chip_delay setup, set 20us if not */
+	if (!chip->legacy.chip_delay)
+		chip->legacy.chip_delay = 20;
+
+	/* check, if a user supplied command function given */
+	if (!chip->legacy.cmdfunc && !chip->exec_op)
+		chip->legacy.cmdfunc = nand_command;
+
+	/* check, if a user supplied wait function given */
+	if (chip->legacy.waitfunc == NULL)
+		chip->legacy.waitfunc = nand_wait;
+
+	if (!chip->select_chip)
+		chip->select_chip = nand_select_chip;
+
+	/* If called twice, pointers that depend on busw may need to be reset */
+	if (!chip->legacy.read_byte || chip->legacy.read_byte == nand_read_byte)
+		chip->legacy.read_byte = busw ? nand_read_byte16 : nand_read_byte;
+	if (!chip->legacy.write_buf || chip->legacy.write_buf == nand_write_buf)
+		chip->legacy.write_buf = busw ? nand_write_buf16 : nand_write_buf;
+	if (!chip->legacy.write_byte || chip->legacy.write_byte == nand_write_byte)
+		chip->legacy.write_byte = busw ? nand_write_byte16 : nand_write_byte;
+	if (!chip->legacy.read_buf || chip->legacy.read_buf == nand_read_buf)
+		chip->legacy.read_buf = busw ? nand_read_buf16 : nand_read_buf;
+}
+
+void nand_legacy_adjust_cmdfunc(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	/* Do not replace user supplied command function! */
+	if (mtd->writesize > 512 && chip->legacy.cmdfunc == nand_command)
+		chip->legacy.cmdfunc = nand_command_lp;
+}
+
+int nand_legacy_check_hooks(struct nand_chip *chip)
+{
+	/*
+	 * ->legacy.cmdfunc() is legacy and will only be used if ->exec_op() is
+	 * not populated.
+	 */
+	if (chip->exec_op)
+		return 0;
+
+	/*
+	 * Default functions assigned for ->legacy.cmdfunc() and
+	 * ->select_chip() both expect ->legacy.cmd_ctrl() to be populated.
+	 */
+	if ((!chip->legacy.cmdfunc || !chip->select_chip) &&
+	    !chip->legacy.cmd_ctrl) {
+		pr_err("->legacy.cmd_ctrl() should be provided\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}