summaryrefslogtreecommitdiff
path: root/drivers/mtd/nand/at91_nand.c
blob: 512e999177f70cb39c745ac6d454d22e6a4c3bae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
/*
 * drivers/mtd/nand/at91_nand.c
 *
 *  Copyright (C) 2003 Rick Bronson
 *
 *  Derived from drivers/mtd/nand/autcpu12.c
 *	 Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
 *
 *  Derived from drivers/mtd/spia.c
 *	 Copyright (C) 2000 Steven J. Hill (sjhill@cotw.com)
 *
 * 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/platform_device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>

#include <asm/io.h>
#include <asm/sizes.h>

#include <asm/hardware.h>
#include <asm/arch/board.h>
#include <asm/arch/gpio.h>

struct at91_nand_host {
	struct nand_chip	nand_chip;
	struct mtd_info		mtd;
	void __iomem		*io_base;
	struct at91_nand_data	*board;
};

/*
 * Hardware specific access to control-lines
 */
static void at91_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
	struct nand_chip *nand_chip = mtd->priv;
	struct at91_nand_host *host = nand_chip->priv;

	if (cmd == NAND_CMD_NONE)
		return;

	if (ctrl & NAND_CLE)
		writeb(cmd, host->io_base + (1 << host->board->cle));
	else
		writeb(cmd, host->io_base + (1 << host->board->ale));
}

/*
 * Read the Device Ready pin.
 */
static int at91_nand_device_ready(struct mtd_info *mtd)
{
	struct nand_chip *nand_chip = mtd->priv;
	struct at91_nand_host *host = nand_chip->priv;

	return at91_get_gpio_value(host->board->rdy_pin);
}

/*
 * Enable NAND.
 */
static void at91_nand_enable(struct at91_nand_host *host)
{
	if (host->board->enable_pin)
		at91_set_gpio_value(host->board->enable_pin, 0);
}

/*
 * Disable NAND.
 */
static void at91_nand_disable(struct at91_nand_host *host)
{
	if (host->board->enable_pin)
		at91_set_gpio_value(host->board->enable_pin, 1);
}

#ifdef CONFIG_MTD_PARTITIONS
const char *part_probes[] = { "cmdlinepart", NULL };
#endif

/*
 * Probe for the NAND device.
 */
static int __init at91_nand_probe(struct platform_device *pdev)
{
	struct at91_nand_host *host;
	struct mtd_info *mtd;
	struct nand_chip *nand_chip;
	int res;

#ifdef CONFIG_MTD_PARTITIONS
	struct mtd_partition *partitions = NULL;
	int num_partitions = 0;
#endif

	/* Allocate memory for the device structure (and zero it) */
	host = kzalloc(sizeof(struct at91_nand_host), GFP_KERNEL);
	if (!host) {
		printk(KERN_ERR "at91_nand: failed to allocate device structure.\n");
		return -ENOMEM;
	}

	host->io_base = ioremap(pdev->resource[0].start,
				pdev->resource[0].end - pdev->resource[0].start + 1);
	if (host->io_base == NULL) {
		printk(KERN_ERR "at91_nand: ioremap failed\n");
		kfree(host);
		return -EIO;
	}

	mtd = &host->mtd;
	nand_chip = &host->nand_chip;
	host->board = pdev->dev.platform_data;

	nand_chip->priv = host;		/* link the private data structures */
	mtd->priv = nand_chip;
	mtd->owner = THIS_MODULE;

	/* Set address of NAND IO lines */
	nand_chip->IO_ADDR_R = host->io_base;
	nand_chip->IO_ADDR_W = host->io_base;
	nand_chip->cmd_ctrl = at91_nand_cmd_ctrl;
	nand_chip->dev_ready = at91_nand_device_ready;
	nand_chip->ecc.mode = NAND_ECC_SOFT;	/* enable ECC */
	nand_chip->chip_delay = 20;		/* 20us command delay time */

	if (host->board->bus_width_16)		/* 16-bit bus width */
		nand_chip->options |= NAND_BUSWIDTH_16;

	platform_set_drvdata(pdev, host);
	at91_nand_enable(host);

	if (host->board->det_pin) {
		if (at91_get_gpio_value(host->board->det_pin)) {
			printk ("No SmartMedia card inserted.\n");
			res = ENXIO;
			goto out;
		}
	}

	/* Scan to find existance of the device */
	if (nand_scan(mtd, 1)) {
		res = -ENXIO;
		goto out;
	}

#ifdef CONFIG_MTD_PARTITIONS
	if (host->board->partition_info)
		partitions = host->board->partition_info(mtd->size, &num_partitions);
#ifdef CONFIG_MTD_CMDLINE_PARTS
	else {
		mtd->name = "at91_nand";
		num_partitions = parse_mtd_partitions(mtd, part_probes, &partitions, 0);
	}
#endif

	if ((!partitions) || (num_partitions == 0)) {
		printk(KERN_ERR "at91_nand: No parititions defined, or unsupported device.\n");
		res = ENXIO;
		goto release;
	}

	res = add_mtd_partitions(mtd, partitions, num_partitions);
#else
	res = add_mtd_device(mtd);
#endif

	if (!res)
		return res;

release:
	nand_release(mtd);
out:
	at91_nand_disable(host);
	platform_set_drvdata(pdev, NULL);
	iounmap(host->io_base);
	kfree(host);
	return res;
}

/*
 * Remove a NAND device.
 */
static int __devexit at91_nand_remove(struct platform_device *pdev)
{
	struct at91_nand_host *host = platform_get_drvdata(pdev);
	struct mtd_info *mtd = &host->mtd;

	nand_release(mtd);

	at91_nand_disable(host);

	iounmap(host->io_base);
	kfree(host);

	return 0;
}

static struct platform_driver at91_nand_driver = {
	.probe		= at91_nand_probe,
	.remove		= at91_nand_remove,
	.driver		= {
		.name	= "at91_nand",
		.owner	= THIS_MODULE,
	},
};

static int __init at91_nand_init(void)
{
	return platform_driver_register(&at91_nand_driver);
}


static void __exit at91_nand_exit(void)
{
	platform_driver_unregister(&at91_nand_driver);
}


module_init(at91_nand_init);
module_exit(at91_nand_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Rick Bronson");
MODULE_DESCRIPTION("NAND/SmartMedia driver for AT91RM9200");