[deliverable/linux.git] / drivers / mtd / nand / socrates_nand.c

/*
 * drivers/mtd/nand/socrates_nand.c
 *
 *  Copyright © 2008 Ilya Yanok, Emcraft Systems
 *
 *
 * 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.
 *
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <linux/of_platform.h>
#include <linux/io.h>

#define FPGA_NAND_CMD_MASK		(0x7 << 28)
#define FPGA_NAND_CMD_COMMAND		(0x0 << 28)
#define FPGA_NAND_CMD_ADDR		(0x1 << 28)
#define FPGA_NAND_CMD_READ		(0x2 << 28)
#define FPGA_NAND_CMD_WRITE		(0x3 << 28)
#define FPGA_NAND_BUSY			(0x1 << 15)
#define FPGA_NAND_ENABLE		(0x1 << 31)
#define FPGA_NAND_DATA_SHIFT		16

struct socrates_nand_host {
	struct nand_chip	nand_chip;
	struct mtd_info		mtd;
	void __iomem		*io_base;
	struct device		*dev;
};

/**
 * socrates_nand_write_buf -  write buffer to chip
 * @mtd:	MTD device structure
 * @buf:	data buffer
 * @len:	number of bytes to write
 */
static void socrates_nand_write_buf(struct mtd_info *mtd,
		const uint8_t *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;
	struct socrates_nand_host *host = this->priv;

	for (i = 0; i < len; i++) {
		out_be32(host->io_base, FPGA_NAND_ENABLE |
				FPGA_NAND_CMD_WRITE |
				(buf[i] << FPGA_NAND_DATA_SHIFT));
	}
}

/**
 * socrates_nand_read_buf -  read chip data into buffer
 * @mtd:	MTD device structure
 * @buf:	buffer to store date
 * @len:	number of bytes to read
 */
static void socrates_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;
	struct socrates_nand_host *host = this->priv;
	uint32_t val;

	val = FPGA_NAND_ENABLE | FPGA_NAND_CMD_READ;

	out_be32(host->io_base, val);
	for (i = 0; i < len; i++) {
		buf[i] = (in_be32(host->io_base) >>
				FPGA_NAND_DATA_SHIFT) & 0xff;
	}
}

/**
 * socrates_nand_read_byte -  read one byte from the chip
 * @mtd:	MTD device structure
 */
static uint8_t socrates_nand_read_byte(struct mtd_info *mtd)
{
	uint8_t byte;
	socrates_nand_read_buf(mtd, &byte, sizeof(byte));
	return byte;
}

/**
 * socrates_nand_read_word -  read one word from the chip
 * @mtd:	MTD device structure
 */
static uint16_t socrates_nand_read_word(struct mtd_info *mtd)
{
	uint16_t word;
	socrates_nand_read_buf(mtd, (uint8_t *)&word, sizeof(word));
	return word;
}

/**
 * socrates_nand_verify_buf -  Verify chip data against buffer
 * @mtd:	MTD device structure
 * @buf:	buffer containing the data to compare
 * @len:	number of bytes to compare
 */
static int socrates_nand_verify_buf(struct mtd_info *mtd, const u8 *buf,
		int len)
{
	int i;

	for (i = 0; i < len; i++) {
		if (buf[i] != socrates_nand_read_byte(mtd))
			return -EFAULT;
	}
	return 0;
}

/*
 * Hardware specific access to control-lines
 */
static void socrates_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
		unsigned int ctrl)
{
	struct nand_chip *nand_chip = mtd->priv;
	struct socrates_nand_host *host = nand_chip->priv;
	uint32_t val;

	if (cmd == NAND_CMD_NONE)
		return;

	if (ctrl & NAND_CLE)
		val = FPGA_NAND_CMD_COMMAND;
	else
		val = FPGA_NAND_CMD_ADDR;

	if (ctrl & NAND_NCE)
		val |= FPGA_NAND_ENABLE;

	val |= (cmd & 0xff) << FPGA_NAND_DATA_SHIFT;

	out_be32(host->io_base, val);
}

/*
 * Read the Device Ready pin.
 */
static int socrates_nand_device_ready(struct mtd_info *mtd)
{
	struct nand_chip *nand_chip = mtd->priv;
	struct socrates_nand_host *host = nand_chip->priv;

	if (in_be32(host->io_base) & FPGA_NAND_BUSY)
		return 0; /* busy */
	return 1;
}

/*
 * Probe for the NAND device.
 */
static int __devinit socrates_nand_probe(struct platform_device *ofdev)
{
	struct socrates_nand_host *host;
	struct mtd_info *mtd;
	struct nand_chip *nand_chip;
	int res;
	struct mtd_partition *partitions = NULL;
	int num_partitions = 0;
	struct mtd_part_parser_data ppdata;

	/* Allocate memory for the device structure (and zero it) */
	host = kzalloc(sizeof(struct socrates_nand_host), GFP_KERNEL);
	if (!host) {
		printk(KERN_ERR
		       "socrates_nand: failed to allocate device structure.\n");
		return -ENOMEM;
	}

	host->io_base = of_iomap(ofdev->dev.of_node, 0);
	if (host->io_base == NULL) {
		printk(KERN_ERR "socrates_nand: ioremap failed\n");
		kfree(host);
		return -EIO;
	}

	mtd = &host->mtd;
	nand_chip = &host->nand_chip;
	host->dev = &ofdev->dev;

	nand_chip->priv = host;		/* link the private data structures */
	mtd->priv = nand_chip;
	mtd->name = "socrates_nand";
	mtd->owner = THIS_MODULE;
	mtd->dev.parent = &ofdev->dev;
	ppdata.of_node = ofdev->dev.of_node;

	/*should never be accessed directly */
	nand_chip->IO_ADDR_R = (void *)0xdeadbeef;
	nand_chip->IO_ADDR_W = (void *)0xdeadbeef;

	nand_chip->cmd_ctrl = socrates_nand_cmd_ctrl;
	nand_chip->read_byte = socrates_nand_read_byte;
	nand_chip->read_word = socrates_nand_read_word;
	nand_chip->write_buf = socrates_nand_write_buf;
	nand_chip->read_buf = socrates_nand_read_buf;
	nand_chip->verify_buf = socrates_nand_verify_buf;
	nand_chip->dev_ready = socrates_nand_device_ready;

	nand_chip->ecc.mode = NAND_ECC_SOFT;	/* enable ECC */

	/* TODO: I have no idea what real delay is. */
	nand_chip->chip_delay = 20;		/* 20us command delay time */

	dev_set_drvdata(&ofdev->dev, host);

	/* first scan to find the device and get the page size */
	if (nand_scan_ident(mtd, 1, NULL)) {
		res = -ENXIO;
		goto out;
	}

	/* second phase scan */
	if (nand_scan_tail(mtd)) {
		res = -ENXIO;
		goto out;
	}

	num_partitions = parse_mtd_partitions(mtd, NULL, &partitions, &ppdata);
	if (num_partitions < 0) {
		res = num_partitions;
		goto release;
	}

	res = mtd_device_register(mtd, partitions, num_partitions);
	if (!res)
		return res;

release:
	nand_release(mtd);

out:
	dev_set_drvdata(&ofdev->dev, NULL);
	iounmap(host->io_base);
	kfree(host);
	return res;
}

/*
 * Remove a NAND device.
 */
static int __devexit socrates_nand_remove(struct platform_device *ofdev)
{
	struct socrates_nand_host *host = dev_get_drvdata(&ofdev->dev);
	struct mtd_info *mtd = &host->mtd;

	nand_release(mtd);

	dev_set_drvdata(&ofdev->dev, NULL);
	iounmap(host->io_base);
	kfree(host);

	return 0;
}

static const struct of_device_id socrates_nand_match[] =
{
	{
		.compatible   = "abb,socrates-nand",
	},
	{},
};

MODULE_DEVICE_TABLE(of, socrates_nand_match);

static struct platform_driver socrates_nand_driver = {
	.driver = {
		.name = "socrates_nand",
		.owner = THIS_MODULE,
		.of_match_table = socrates_nand_match,
	},
	.probe		= socrates_nand_probe,
	.remove		= __devexit_p(socrates_nand_remove),
};

static int __init socrates_nand_init(void)
{
	return platform_driver_register(&socrates_nand_driver);
}

static void __exit socrates_nand_exit(void)
{
	platform_driver_unregister(&socrates_nand_driver);
}

module_init(socrates_nand_init);
module_exit(socrates_nand_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ilya Yanok");
MODULE_DESCRIPTION("NAND driver for Socrates board");
Commit	Line	Data
1b578193 WG	1	/*
	2	* drivers/mtd/nand/socrates_nand.c
	3	*
	4	* Copyright © 2008 Ilya Yanok, Emcraft Systems
	5	*
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	*/
	12
	13	#include <linux/slab.h>
	14	#include <linux/module.h>
	15	#include <linux/mtd/mtd.h>
	16	#include <linux/mtd/nand.h>
	17	#include <linux/mtd/partitions.h>
	18	#include <linux/of_platform.h>
	19	#include <linux/io.h>
	20
	21	#define FPGA_NAND_CMD_MASK (0x7 << 28)
	22	#define FPGA_NAND_CMD_COMMAND (0x0 << 28)
	23	#define FPGA_NAND_CMD_ADDR (0x1 << 28)
	24	#define FPGA_NAND_CMD_READ (0x2 << 28)
	25	#define FPGA_NAND_CMD_WRITE (0x3 << 28)
	26	#define FPGA_NAND_BUSY (0x1 << 15)
	27	#define FPGA_NAND_ENABLE (0x1 << 31)
	28	#define FPGA_NAND_DATA_SHIFT 16
	29
	30	struct socrates_nand_host {
	31	struct nand_chip nand_chip;
	32	struct mtd_info mtd;
	33	void __iomem *io_base;
	34	struct device *dev;
	35	};
	36
	37	/**
	38	* socrates_nand_write_buf - write buffer to chip
	39	* @mtd: MTD device structure
	40	* @buf: data buffer
	41	* @len: number of bytes to write
	42	*/
	43	static void socrates_nand_write_buf(struct mtd_info *mtd,
	44	const uint8_t *buf, int len)
	45	{
	46	int i;
	47	struct nand_chip *this = mtd->priv;
	48	struct socrates_nand_host *host = this->priv;
	49
	50	for (i = 0; i < len; i++) {
	51	out_be32(host->io_base, FPGA_NAND_ENABLE \|
	52	FPGA_NAND_CMD_WRITE \|
	53	(buf[i] << FPGA_NAND_DATA_SHIFT));
	54	}
	55	}
	56
	57	/**
	58	* socrates_nand_read_buf - read chip data into buffer
	59	* @mtd: MTD device structure
	60	* @buf: buffer to store date
	61	* @len: number of bytes to read
	62	*/
	63	static void socrates_nand_read_buf(struct mtd_info mtd, uint8_t buf, int len)
	64	{
65	int i;
66	struct nand_chip *this = mtd->priv;
67	struct socrates_nand_host *host = this->priv;
68	uint32_t val;
69
70	val = FPGA_NAND_ENABLE \| FPGA_NAND_CMD_READ;
71
72	out_be32(host->io_base, val);
73	for (i = 0; i < len; i++) {
74	buf[i] = (in_be32(host->io_base) >>
75	FPGA_NAND_DATA_SHIFT) & 0xff;
76	}
77	}
78
79	/**
80	* socrates_nand_read_byte - read one byte from the chip
81	* @mtd: MTD device structure
82	*/
83	static uint8_t socrates_nand_read_byte(struct mtd_info *mtd)
84	{
85	uint8_t byte;
86	socrates_nand_read_buf(mtd, &byte, sizeof(byte));
87	return byte;
88	}
89
90	/**
91	* socrates_nand_read_word - read one word from the chip
92	* @mtd: MTD device structure
93	*/
94	static uint16_t socrates_nand_read_word(struct mtd_info *mtd)
95	{
96	uint16_t word;
97	socrates_nand_read_buf(mtd, (uint8_t *)&word, sizeof(word));
98	return word;
99	}
100
101	/**
102	* socrates_nand_verify_buf - Verify chip data against buffer
103	* @mtd: MTD device structure
104	* @buf: buffer containing the data to compare
105	* @len: number of bytes to compare
106	*/
107	static int socrates_nand_verify_buf(struct mtd_info mtd, const u8 buf,
108	int len)
109	{
110	int i;
111
112	for (i = 0; i < len; i++) {
113	if (buf[i] != socrates_nand_read_byte(mtd))
114	return -EFAULT;
115	}
116	return 0;
117	}
118
119	/*
120	* Hardware specific access to control-lines
121	*/
122	static void socrates_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
123	unsigned int ctrl)
124	{
125	struct nand_chip *nand_chip = mtd->priv;
126	struct socrates_nand_host *host = nand_chip->priv;
127	uint32_t val;
128
129	if (cmd == NAND_CMD_NONE)
130	return;
131
132	if (ctrl & NAND_CLE)
133	val = FPGA_NAND_CMD_COMMAND;
134	else
135	val = FPGA_NAND_CMD_ADDR;
136
137	if (ctrl & NAND_NCE)
138	val \|= FPGA_NAND_ENABLE;
139
140	val \|= (cmd & 0xff) << FPGA_NAND_DATA_SHIFT;
141
142	out_be32(host->io_base, val);
143	}
144
145	/*
146	* Read the Device Ready pin.
147	*/
148	static int socrates_nand_device_ready(struct mtd_info *mtd)
149	{
150	struct nand_chip *nand_chip = mtd->priv;
151	struct socrates_nand_host *host = nand_chip->priv;
152
153	if (in_be32(host->io_base) & FPGA_NAND_BUSY)
154	return 0; /* busy */
155	return 1;
156	}
157
1b578193 WG	158	/*
	159	* Probe for the NAND device.
	160	*/
1c48a5c9	161	static int __devinit socrates_nand_probe(struct platform_device *ofdev)
1b578193 WG	162	{
	163	struct socrates_nand_host *host;
	164	struct mtd_info *mtd;
	165	struct nand_chip *nand_chip;
	166	int res;
1b578193 WG	167	struct mtd_partition *partitions = NULL;
1b578193 WG	168	int num_partitions = 0;
2cd9ea52	169	struct mtd_part_parser_data ppdata;
1b578193 WG	170
	171	/* Allocate memory for the device structure (and zero it) */
	172	host = kzalloc(sizeof(struct socrates_nand_host), GFP_KERNEL);
	173	if (!host) {
	174	printk(KERN_ERR
	175	"socrates_nand: failed to allocate device structure.\n");
	176	return -ENOMEM;
	177	}
	178
c8a4d0fd	179	host->io_base = of_iomap(ofdev->dev.of_node, 0);
1b578193 WG	180	if (host->io_base == NULL) {
	181	printk(KERN_ERR "socrates_nand: ioremap failed\n");
	182	kfree(host);
	183	return -EIO;
	184	}
	185
	186	mtd = &host->mtd;
	187	nand_chip = &host->nand_chip;
	188	host->dev = &ofdev->dev;
	189
	190	nand_chip->priv = host; /* link the private data structures */
	191	mtd->priv = nand_chip;
	192	mtd->name = "socrates_nand";
	193	mtd->owner = THIS_MODULE;
	194	mtd->dev.parent = &ofdev->dev;
2cd9ea52	195	ppdata.of_node = ofdev->dev.of_node;
1b578193 WG	196
	197	/should never be accessed directly /
	198	nand_chip->IO_ADDR_R = (void *)0xdeadbeef;
	199	nand_chip->IO_ADDR_W = (void *)0xdeadbeef;
	200
	201	nand_chip->cmd_ctrl = socrates_nand_cmd_ctrl;
	202	nand_chip->read_byte = socrates_nand_read_byte;
	203	nand_chip->read_word = socrates_nand_read_word;
	204	nand_chip->write_buf = socrates_nand_write_buf;
	205	nand_chip->read_buf = socrates_nand_read_buf;
	206	nand_chip->verify_buf = socrates_nand_verify_buf;
	207	nand_chip->dev_ready = socrates_nand_device_ready;
	208
	209	nand_chip->ecc.mode = NAND_ECC_SOFT; /* enable ECC */
	210
	211	/* TODO: I have no idea what real delay is. */
	212	nand_chip->chip_delay = 20; /* 20us command delay time */
	213
	214	dev_set_drvdata(&ofdev->dev, host);
	215
	216	/* first scan to find the device and get the page size */
5e81e88a	217	if (nand_scan_ident(mtd, 1, NULL)) {
1b578193 WG	218	res = -ENXIO;
	219	goto out;
	220	}
	221
	222	/* second phase scan */
	223	if (nand_scan_tail(mtd)) {
	224	res = -ENXIO;
	225	goto out;
	226	}
	227
2cd9ea52	228	num_partitions = parse_mtd_partitions(mtd, NULL, &partitions, &ppdata);
1b578193 WG	229	if (num_partitions < 0) {
	230	res = num_partitions;
	231	goto release;
	232	}
1b578193	233
5667bc8a	234	res = mtd_device_register(mtd, partitions, num_partitions);
1b578193 WG	235	if (!res)
	236	return res;
	237
1b578193	238	release:
1b578193 WG	239	nand_release(mtd);
	240
	241	out:
	242	dev_set_drvdata(&ofdev->dev, NULL);
	243	iounmap(host->io_base);
	244	kfree(host);
	245	return res;
	246	}
	247
	248	/*
	249	* Remove a NAND device.
	250	*/
2dc11581	251	static int __devexit socrates_nand_remove(struct platform_device *ofdev)
1b578193 WG	252	{
	253	struct socrates_nand_host *host = dev_get_drvdata(&ofdev->dev);
	254	struct mtd_info *mtd = &host->mtd;
	255
	256	nand_release(mtd);
	257
	258	dev_set_drvdata(&ofdev->dev, NULL);
	259	iounmap(host->io_base);
	260	kfree(host);
	261
	262	return 0;
	263	}
	264
b2d4fbab	265	static const struct of_device_id socrates_nand_match[] =
1b578193 WG	266	{
	267	{
	268	.compatible = "abb,socrates-nand",
	269	},
	270	{},
	271	};
	272
	273	MODULE_DEVICE_TABLE(of, socrates_nand_match);
	274
1c48a5c9	275	static struct platform_driver socrates_nand_driver = {
4018294b GL	276	.driver = {
	277	.name = "socrates_nand",
	278	.owner = THIS_MODULE,
	279	.of_match_table = socrates_nand_match,
	280	},
1b578193 WG	281	.probe = socrates_nand_probe,
	282	.remove = __devexit_p(socrates_nand_remove),
	283	};
	284
	285	static int __init socrates_nand_init(void)
	286	{
1c48a5c9	287	return platform_driver_register(&socrates_nand_driver);
1b578193 WG	288	}
	289
	290	static void __exit socrates_nand_exit(void)
	291	{
1c48a5c9	292	platform_driver_unregister(&socrates_nand_driver);
1b578193 WG	293	}
	294
	295	module_init(socrates_nand_init);
	296	module_exit(socrates_nand_exit);
	297
	298	MODULE_LICENSE("GPL");
	299	MODULE_AUTHOR("Ilya Yanok");
	300	MODULE_DESCRIPTION("NAND driver for Socrates board");