summaryrefslogtreecommitdiff
path: root/drivers/mtd/nand/excite_nandflash.c
blob: 72446fb48d4b90321be0c3611d57d8a9e02877f3 (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
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
/*
*  Copyright (C) 2005 - 2007 by Basler Vision Technologies AG
*  Author: Thomas Koeller <thomas.koeller.qbaslerweb.com>
*  Original code by Thies Moeller <thies.moeller@baslerweb.com>
*
*  This program is free software; you can redistribute it and/or modify
*  it under the terms of the GNU General Public License as published by
*  the Free Software Foundation; either version 2 of the License, or
*  (at your option) any later version.
*
*  This program is distributed in the hope that it will be useful,
*  but WITHOUT ANY WARRANTY; without even the implied warranty of
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*  GNU General Public License for more details.
*
*  You should have received a copy of the GNU General Public License
*  along with this program; if not, write to the Free Software
*  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/err.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/partitions.h>

#include <asm/io.h>
#include <asm/rm9k-ocd.h>

#include <excite_nandflash.h>

#define EXCITE_NANDFLASH_VERSION "0.1"

/* I/O register offsets */
#define EXCITE_NANDFLASH_DATA_BYTE   0x00
#define EXCITE_NANDFLASH_STATUS_BYTE 0x0c
#define EXCITE_NANDFLASH_ADDR_BYTE   0x10
#define EXCITE_NANDFLASH_CMD_BYTE    0x14

/* prefix for debug output */
static const char module_id[] = "excite_nandflash";

/*
 * partition definition
 */
static const struct mtd_partition partition_info[] = {
	{
		.name = "eXcite RootFS",
		.offset = 0,
		.size = MTDPART_SIZ_FULL
	}
};

static inline const struct resource *
excite_nand_get_resource(struct platform_device *d, unsigned long flags,
			 const char *basename)
{
	char buf[80];

	if (snprintf(buf, sizeof buf, "%s_%u", basename, d->id) >= sizeof buf)
		return NULL;
	return platform_get_resource_byname(d, flags, buf);
}

static inline void __iomem *
excite_nand_map_regs(struct platform_device *d, const char *basename)
{
	void *result = NULL;
	const struct resource *const r =
	    excite_nand_get_resource(d, IORESOURCE_MEM, basename);

	if (r)
		result = ioremap_nocache(r->start, r->end + 1 - r->start);
	return result;
}

/* controller and mtd information */
struct excite_nand_drvdata {
	struct mtd_info board_mtd;
	struct nand_chip board_chip;
	void __iomem *regs;
	void __iomem *tgt;
};

/* Control function */
static void excite_nand_control(struct mtd_info *mtd, int cmd,
				       unsigned int ctrl)
{
	struct excite_nand_drvdata * const d =
	    container_of(mtd, struct excite_nand_drvdata, board_mtd);

	switch (ctrl) {
	case NAND_CTRL_CHANGE | NAND_CTRL_CLE:
		d->tgt = d->regs + EXCITE_NANDFLASH_CMD_BYTE;
		break;
	case NAND_CTRL_CHANGE | NAND_CTRL_ALE:
		d->tgt = d->regs + EXCITE_NANDFLASH_ADDR_BYTE;
		break;
	case NAND_CTRL_CHANGE | NAND_NCE:
		d->tgt = d->regs + EXCITE_NANDFLASH_DATA_BYTE;
		break;
	}

	if (cmd != NAND_CMD_NONE)
		__raw_writeb(cmd, d->tgt);
}

/* Return 0 if flash is busy, 1 if ready */
static int excite_nand_devready(struct mtd_info *mtd)
{
	struct excite_nand_drvdata * const drvdata =
	    container_of(mtd, struct excite_nand_drvdata, board_mtd);

	return __raw_readb(drvdata->regs + EXCITE_NANDFLASH_STATUS_BYTE);
}

/*
 * Called by device layer to remove the driver.
 * The binding to the mtd and all allocated
 * resources are released.
 */
static int __exit excite_nand_remove(struct platform_device *dev)
{
	struct excite_nand_drvdata * const this = platform_get_drvdata(dev);

	platform_set_drvdata(dev, NULL);

	if (unlikely(!this)) {
		printk(KERN_ERR "%s: called %s without private data!!",
		       module_id, __func__);
		return -EINVAL;
	}

	/* first thing we need to do is release our mtd
	 * then go through freeing the resource used
	 */
	nand_release(&this->board_mtd);

	/* free the common resources */
	iounmap(this->regs);
	kfree(this);

	DEBUG(MTD_DEBUG_LEVEL1, "%s: removed\n", module_id);
	return 0;
}

/*
 * Called by device layer when it finds a device matching
 * one our driver can handle. This code checks to see if
 * it can allocate all necessary resources then calls the
 * nand layer to look for devices.
*/
static int __init excite_nand_probe(struct platform_device *pdev)
{
	struct excite_nand_drvdata *drvdata;	/* private driver data */
	struct nand_chip *board_chip;	/* private flash chip data */
	struct mtd_info *board_mtd;	/* mtd info for this board */
	int scan_res;

	drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
	if (unlikely(!drvdata)) {
		printk(KERN_ERR "%s: no memory for drvdata\n",
		       module_id);
		return -ENOMEM;
	}

	/* bind private data into driver */
	platform_set_drvdata(pdev, drvdata);

	/* allocate and map the resource */
	drvdata->regs =
		excite_nand_map_regs(pdev, EXCITE_NANDFLASH_RESOURCE_REGS);

	if (unlikely(!drvdata->regs)) {
		printk(KERN_ERR "%s: cannot reserve register region\n",
		       module_id);
		kfree(drvdata);
		return -ENXIO;
	}
	
	drvdata->tgt = drvdata->regs + EXCITE_NANDFLASH_DATA_BYTE;

	/* initialise our chip */
	board_chip = &drvdata->board_chip;
	board_chip->IO_ADDR_R = board_chip->IO_ADDR_W =
		drvdata->regs + EXCITE_NANDFLASH_DATA_BYTE;
	board_chip->cmd_ctrl = excite_nand_control;
	board_chip->dev_ready = excite_nand_devready;
	board_chip->chip_delay = 25;
	board_chip->ecc.mode = NAND_ECC_SOFT;

	/* link chip to mtd */
	board_mtd = &drvdata->board_mtd;
	board_mtd->priv = board_chip;

	DEBUG(MTD_DEBUG_LEVEL2, "%s: device scan\n", module_id);
	scan_res = nand_scan(&drvdata->board_mtd, 1);

	if (likely(!scan_res)) {
		DEBUG(MTD_DEBUG_LEVEL2, "%s: register partitions\n", module_id);
		add_mtd_partitions(&drvdata->board_mtd, partition_info,
				   ARRAY_SIZE(partition_info));
	} else {
		iounmap(drvdata->regs);
		kfree(drvdata);
		printk(KERN_ERR "%s: device scan failed\n", module_id);
		return -EIO;
	}
	return 0;
}

static struct platform_driver excite_nand_driver = {
	.driver = {
		.name = "excite_nand",
		.owner		= THIS_MODULE,
	},
	.probe = excite_nand_probe,
	.remove = __devexit_p(excite_nand_remove)
};

static int __init excite_nand_init(void)
{
	pr_info("Basler eXcite nand flash driver Version "
		EXCITE_NANDFLASH_VERSION "\n");
	return platform_driver_register(&excite_nand_driver);
}

static void __exit excite_nand_exit(void)
{
	platform_driver_unregister(&excite_nand_driver);
}

module_init(excite_nand_init);
module_exit(excite_nand_exit);

MODULE_AUTHOR("Thomas Koeller <thomas.koeller@baslerweb.com>");
MODULE_DESCRIPTION("Basler eXcite NAND-Flash driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(EXCITE_NANDFLASH_VERSION)