drivers/mtd/nand/xway_nand.c - linux - Git at Google

 /*
  *  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.
  *
  *  Copyright © 2012 John Crispin <john@phrozen.org>
  *  Copyright © 2016 Hauke Mehrtens <hauke@hauke-m.de>
  */

 #include <linux/mtd/nand.h>
 #include <linux/of_gpio.h>
 #include <linux/of_platform.h>

 #include <lantiq_soc.h>

 /* nand registers */
 #define EBU_ADDSEL1		0x24
 #define EBU_NAND_CON		0xB0
 #define EBU_NAND_WAIT		0xB4
 #define  NAND_WAIT_RD		BIT(0) /* NAND flash status output */
 #define  NAND_WAIT_WR_C		BIT(3) /* NAND Write/Read complete */
 #define EBU_NAND_ECC0		0xB8
 #define EBU_NAND_ECC_AC		0xBC

 /*
  * nand commands
  * The pins of the NAND chip are selected based on the address bits of the
  * "register" read and write. There are no special registers, but an
  * address range and the lower address bits are used to activate the
  * correct line. For example when the bit (1 << 2) is set in the address
  * the ALE pin will be activated.
  */
 #define NAND_CMD_ALE		BIT(2) /* address latch enable */
 #define NAND_CMD_CLE		BIT(3) /* command latch enable */
 #define NAND_CMD_CS		BIT(4) /* chip select */
 #define NAND_CMD_SE		BIT(5) /* spare area access latch */
 #define NAND_CMD_WP		BIT(6) /* write protect */
 #define NAND_WRITE_CMD		(NAND_CMD_CS | NAND_CMD_CLE)
 #define NAND_WRITE_ADDR		(NAND_CMD_CS | NAND_CMD_ALE)
 #define NAND_WRITE_DATA		(NAND_CMD_CS)
 #define NAND_READ_DATA		(NAND_CMD_CS)

 /* we need to tel the ebu which addr we mapped the nand to */
 #define ADDSEL1_MASK(x)		(x << 4)
 #define ADDSEL1_REGEN		1

 /* we need to tell the EBU that we have nand attached and set it up properly */
 #define BUSCON1_SETUP		(1 << 22)
 #define BUSCON1_BCGEN_RES	(0x3 << 12)
 #define BUSCON1_WAITWRC2	(2 << 8)
 #define BUSCON1_WAITRDC2	(2 << 6)
 #define BUSCON1_HOLDC1		(1 << 4)
 #define BUSCON1_RECOVC1		(1 << 2)
 #define BUSCON1_CMULT4		1

 #define NAND_CON_CE		(1 << 20)
 #define NAND_CON_OUT_CS1	(1 << 10)
 #define NAND_CON_IN_CS1		(1 << 8)
 #define NAND_CON_PRE_P		(1 << 7)
 #define NAND_CON_WP_P		(1 << 6)
 #define NAND_CON_SE_P		(1 << 5)
 #define NAND_CON_CS_P		(1 << 4)
 #define NAND_CON_CSMUX		(1 << 1)
 #define NAND_CON_NANDM		1

 struct xway_nand_data {
 	struct nand_chip	chip;
 	unsigned long		csflags;
 	void __iomem		*nandaddr;
 };

 static u8 xway_readb(struct mtd_info *mtd, int op)
 {
 	struct nand_chip *chip = mtd_to_nand(mtd);
 	struct xway_nand_data *data = nand_get_controller_data(chip);

 	return readb(data->nandaddr + op);
 }

 static void xway_writeb(struct mtd_info *mtd, int op, u8 value)
 {
 	struct nand_chip *chip = mtd_to_nand(mtd);
 	struct xway_nand_data *data = nand_get_controller_data(chip);

 	writeb(value, data->nandaddr + op);
 }

 static void xway_select_chip(struct mtd_info *mtd, int select)
 {
 	struct nand_chip *chip = mtd_to_nand(mtd);
 	struct xway_nand_data *data = nand_get_controller_data(chip);

 	switch (select) {
 	case -1:
 		ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
 		ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
 		spin_unlock_irqrestore(&ebu_lock, data->csflags);
 		break;
 	case 0:
 		spin_lock_irqsave(&ebu_lock, data->csflags);
 		ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
 		ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
 		break;
 	default:
 		BUG();
 	}
 }

 static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
 {
 	if (cmd == NAND_CMD_NONE)
 		return;

 	if (ctrl & NAND_CLE)
 		xway_writeb(mtd, NAND_WRITE_CMD, cmd);
 	else if (ctrl & NAND_ALE)
 		xway_writeb(mtd, NAND_WRITE_ADDR, cmd);

 	while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
 		;
 }

 static int xway_dev_ready(struct mtd_info *mtd)
 {
 	return ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_RD;
 }

 static unsigned char xway_read_byte(struct mtd_info *mtd)
 {
 	return xway_readb(mtd, NAND_READ_DATA);
 }

 static void xway_read_buf(struct mtd_info *mtd, u_char *buf, int len)
 {
 	int i;

 	for (i = 0; i < len; i++)
 		buf[i] = xway_readb(mtd, NAND_WRITE_DATA);
 }

 static void xway_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
 {
 	int i;

 	for (i = 0; i < len; i++)
 		xway_writeb(mtd, NAND_WRITE_DATA, buf[i]);
 }

 /*
  * Probe for the NAND device.
  */
 static int xway_nand_probe(struct platform_device *pdev)
 {
 	struct xway_nand_data *data;
 	struct mtd_info *mtd;
 	struct resource *res;
 	int err;
 	u32 cs;
 	u32 cs_flag = 0;

 	/* Allocate memory for the device structure (and zero it) */
 	data = devm_kzalloc(&pdev->dev, sizeof(struct xway_nand_data),
 			    GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	data->nandaddr = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(data->nandaddr))
 		return PTR_ERR(data->nandaddr);

 	nand_set_flash_node(&data->chip, pdev->dev.of_node);
 	mtd = nand_to_mtd(&data->chip);
 	mtd->dev.parent = &pdev->dev;

 	data->chip.cmd_ctrl = xway_cmd_ctrl;
 	data->chip.dev_ready = xway_dev_ready;
 	data->chip.select_chip = xway_select_chip;
 	data->chip.write_buf = xway_write_buf;
 	data->chip.read_buf = xway_read_buf;
 	data->chip.read_byte = xway_read_byte;
 	data->chip.chip_delay = 30;

 	data->chip.ecc.mode = NAND_ECC_SOFT;
 	data->chip.ecc.algo = NAND_ECC_HAMMING;

 	platform_set_drvdata(pdev, data);
 	nand_set_controller_data(&data->chip, data);

 	/* load our CS from the DT. Either we find a valid 1 or default to 0 */
 	err = of_property_read_u32(pdev->dev.of_node, "lantiq,cs", &cs);
 	if (!err && cs == 1)
 		cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;

 	/* setup the EBU to run in NAND mode on our base addr */
 	ltq_ebu_w32(CPHYSADDR(data->nandaddr)
 		    | ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);

 	ltq_ebu_w32(BUSCON1_SETUP | BUSCON1_BCGEN_RES | BUSCON1_WAITWRC2
 		    | BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
 		    | BUSCON1_CMULT4, LTQ_EBU_BUSCON1);

 	ltq_ebu_w32(NAND_CON_NANDM | NAND_CON_CSMUX | NAND_CON_CS_P
 		    | NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
 		    | cs_flag, EBU_NAND_CON);

 	/* Scan to find existence of the device */
 	err = nand_scan(mtd, 1);
 	if (err)
 		return err;

 	err = mtd_device_register(mtd, NULL, 0);
 	if (err)
 		nand_release(mtd);

 	return err;
 }

 /*
  * Remove a NAND device.
  */
 static int xway_nand_remove(struct platform_device *pdev)
 {
 	struct xway_nand_data *data = platform_get_drvdata(pdev);

 	nand_release(nand_to_mtd(&data->chip));

 	return 0;
 }

 static const struct of_device_id xway_nand_match[] = {
 	{ .compatible = "lantiq,nand-xway" },
 	{},
 };

 static struct platform_driver xway_nand_driver = {
 	.probe	= xway_nand_probe,
 	.remove	= xway_nand_remove,
 	.driver	= {
 		.name		= "lantiq,nand-xway",
 		.of_match_table = xway_nand_match,
 	},
 };

 builtin_platform_driver(xway_nand_driver);
	/*
	* 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.
	*
	* Copyright © 2012 John Crispin <john@phrozen.org>
	* Copyright © 2016 Hauke Mehrtens <hauke@hauke-m.de>
	*/

	#include <linux/mtd/nand.h>
	#include <linux/of_gpio.h>
	#include <linux/of_platform.h>

	#include <lantiq_soc.h>

	/* nand registers */
	#define EBU_ADDSEL1 0x24
	#define EBU_NAND_CON 0xB0
	#define EBU_NAND_WAIT 0xB4
	#define NAND_WAIT_RD BIT(0) /* NAND flash status output */
	#define NAND_WAIT_WR_C BIT(3) /* NAND Write/Read complete */
	#define EBU_NAND_ECC0 0xB8
	#define EBU_NAND_ECC_AC 0xBC

	/*
	* nand commands
	* The pins of the NAND chip are selected based on the address bits of the
	* "register" read and write. There are no special registers, but an
	* address range and the lower address bits are used to activate the
	* correct line. For example when the bit (1 << 2) is set in the address
	* the ALE pin will be activated.
	*/
	#define NAND_CMD_ALE BIT(2) /* address latch enable */
	#define NAND_CMD_CLE BIT(3) /* command latch enable */
	#define NAND_CMD_CS BIT(4) /* chip select */
	#define NAND_CMD_SE BIT(5) /* spare area access latch */
	#define NAND_CMD_WP BIT(6) /* write protect */
	#define NAND_WRITE_CMD (NAND_CMD_CS \| NAND_CMD_CLE)
	#define NAND_WRITE_ADDR (NAND_CMD_CS \| NAND_CMD_ALE)
	#define NAND_WRITE_DATA (NAND_CMD_CS)
	#define NAND_READ_DATA (NAND_CMD_CS)

	/* we need to tel the ebu which addr we mapped the nand to */
	#define ADDSEL1_MASK(x) (x << 4)
	#define ADDSEL1_REGEN 1

	/* we need to tell the EBU that we have nand attached and set it up properly */
	#define BUSCON1_SETUP (1 << 22)
	#define BUSCON1_BCGEN_RES (0x3 << 12)
	#define BUSCON1_WAITWRC2 (2 << 8)
	#define BUSCON1_WAITRDC2 (2 << 6)
	#define BUSCON1_HOLDC1 (1 << 4)
	#define BUSCON1_RECOVC1 (1 << 2)
	#define BUSCON1_CMULT4 1

	#define NAND_CON_CE (1 << 20)
	#define NAND_CON_OUT_CS1 (1 << 10)
	#define NAND_CON_IN_CS1 (1 << 8)
	#define NAND_CON_PRE_P (1 << 7)
	#define NAND_CON_WP_P (1 << 6)
	#define NAND_CON_SE_P (1 << 5)
	#define NAND_CON_CS_P (1 << 4)
	#define NAND_CON_CSMUX (1 << 1)
	#define NAND_CON_NANDM 1

	struct xway_nand_data {
	struct nand_chip chip;
	unsigned long csflags;
	void __iomem *nandaddr;
	};

	static u8 xway_readb(struct mtd_info *mtd, int op)
	{
	struct nand_chip *chip = mtd_to_nand(mtd);
	struct xway_nand_data *data = nand_get_controller_data(chip);

	return readb(data->nandaddr + op);
	}

	static void xway_writeb(struct mtd_info *mtd, int op, u8 value)
	{
	struct nand_chip *chip = mtd_to_nand(mtd);
	struct xway_nand_data *data = nand_get_controller_data(chip);

	writeb(value, data->nandaddr + op);
	}

	static void xway_select_chip(struct mtd_info *mtd, int select)
	{
	struct nand_chip *chip = mtd_to_nand(mtd);
	struct xway_nand_data *data = nand_get_controller_data(chip);

	switch (select) {
	case -1:
	ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
	ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
	spin_unlock_irqrestore(&ebu_lock, data->csflags);
	break;
	case 0:
	spin_lock_irqsave(&ebu_lock, data->csflags);
	ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
	ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
	break;
	default:
	BUG();
	}
	}

	static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
	{
	if (cmd == NAND_CMD_NONE)
	return;

	if (ctrl & NAND_CLE)
	xway_writeb(mtd, NAND_WRITE_CMD, cmd);
	else if (ctrl & NAND_ALE)
	xway_writeb(mtd, NAND_WRITE_ADDR, cmd);

	while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
	;
	}

	static int xway_dev_ready(struct mtd_info *mtd)
	{
	return ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_RD;
	}

	static unsigned char xway_read_byte(struct mtd_info *mtd)
	{
	return xway_readb(mtd, NAND_READ_DATA);
	}

	static void xway_read_buf(struct mtd_info mtd, u_char buf, int len)
	{
	int i;

	for (i = 0; i < len; i++)
	buf[i] = xway_readb(mtd, NAND_WRITE_DATA);
	}

	static void xway_write_buf(struct mtd_info mtd, const u_char buf, int len)
	{
	int i;

	for (i = 0; i < len; i++)
	xway_writeb(mtd, NAND_WRITE_DATA, buf[i]);
	}

	/*
	* Probe for the NAND device.
	*/
	static int xway_nand_probe(struct platform_device *pdev)
	{
	struct xway_nand_data *data;
	struct mtd_info *mtd;
	struct resource *res;
	int err;
	u32 cs;
	u32 cs_flag = 0;

	/* Allocate memory for the device structure (and zero it) */
	data = devm_kzalloc(&pdev->dev, sizeof(struct xway_nand_data),
	GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	data->nandaddr = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(data->nandaddr))
	return PTR_ERR(data->nandaddr);

	nand_set_flash_node(&data->chip, pdev->dev.of_node);
	mtd = nand_to_mtd(&data->chip);
	mtd->dev.parent = &pdev->dev;

	data->chip.cmd_ctrl = xway_cmd_ctrl;
	data->chip.dev_ready = xway_dev_ready;
	data->chip.select_chip = xway_select_chip;
	data->chip.write_buf = xway_write_buf;
	data->chip.read_buf = xway_read_buf;
	data->chip.read_byte = xway_read_byte;
	data->chip.chip_delay = 30;

	data->chip.ecc.mode = NAND_ECC_SOFT;
	data->chip.ecc.algo = NAND_ECC_HAMMING;

	platform_set_drvdata(pdev, data);
	nand_set_controller_data(&data->chip, data);

	/* load our CS from the DT. Either we find a valid 1 or default to 0 */
	err = of_property_read_u32(pdev->dev.of_node, "lantiq,cs", &cs);
	if (!err && cs == 1)
	cs_flag = NAND_CON_IN_CS1 \| NAND_CON_OUT_CS1;

	/* setup the EBU to run in NAND mode on our base addr */
	ltq_ebu_w32(CPHYSADDR(data->nandaddr)
	\| ADDSEL1_MASK(3) \| ADDSEL1_REGEN, EBU_ADDSEL1);

	ltq_ebu_w32(BUSCON1_SETUP \| BUSCON1_BCGEN_RES \| BUSCON1_WAITWRC2
	\| BUSCON1_WAITRDC2 \| BUSCON1_HOLDC1 \| BUSCON1_RECOVC1
	\| BUSCON1_CMULT4, LTQ_EBU_BUSCON1);

	ltq_ebu_w32(NAND_CON_NANDM \| NAND_CON_CSMUX \| NAND_CON_CS_P
	\| NAND_CON_SE_P \| NAND_CON_WP_P \| NAND_CON_PRE_P
	\| cs_flag, EBU_NAND_CON);

	/* Scan to find existence of the device */
	err = nand_scan(mtd, 1);
	if (err)
	return err;

	err = mtd_device_register(mtd, NULL, 0);
	if (err)
	nand_release(mtd);

	return err;
	}

	/*
	* Remove a NAND device.
	*/
	static int xway_nand_remove(struct platform_device *pdev)
	{
	struct xway_nand_data *data = platform_get_drvdata(pdev);

	nand_release(nand_to_mtd(&data->chip));

	return 0;
	}

	static const struct of_device_id xway_nand_match[] = {
	{ .compatible = "lantiq,nand-xway" },
	{},
	};

	static struct platform_driver xway_nand_driver = {
	.probe = xway_nand_probe,
	.remove = xway_nand_remove,
	.driver = {
	.name = "lantiq,nand-xway",
	.of_match_table = xway_nand_match,
	},
	};

	builtin_platform_driver(xway_nand_driver);