summaryrefslogtreecommitdiffstats
path: root/drivers/mtd/nand/gpio.c
blob: 0cde618bcc1e15022612ee0177e02fada244c873 (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
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
/*
 * drivers/mtd/nand/gpio.c
 *
 * Updated, and converted to generic GPIO based driver by Russell King.
 *
 * Written by Ben Dooks <ben@simtec.co.uk>
 *   Based on 2.4 version by Mark Whittaker
 *
 * © 2004 Simtec Electronics
 *
 * Device driver for NAND connected via GPIO
 *
 * 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/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/nand-gpio.h>

struct gpiomtd {
	void __iomem		*io_sync;
	struct mtd_info		mtd_info;
	struct nand_chip	nand_chip;
	struct gpio_nand_platdata plat;
};

#define gpio_nand_getpriv(x) container_of(x, struct gpiomtd, mtd_info)


#ifdef CONFIG_ARM
/* gpio_nand_dosync()
 *
 * Make sure the GPIO state changes occur in-order with writes to NAND
 * memory region.
 * Needed on PXA due to bus-reordering within the SoC itself (see section on
 * I/O ordering in PXA manual (section 2.3, p35)
 */
static void gpio_nand_dosync(struct gpiomtd *gpiomtd)
{
	unsigned long tmp;

	if (gpiomtd->io_sync) {
		/*
		 * Linux memory barriers don't cater for what's required here.
		 * What's required is what's here - a read from a separate
		 * region with a dependency on that read.
		 */
		tmp = readl(gpiomtd->io_sync);
		asm volatile("mov %1, %0\n" : "=r" (tmp) : "r" (tmp));
	}
}
#else
static inline void gpio_nand_dosync(struct gpiomtd *gpiomtd) {}
#endif

static void gpio_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
	struct gpiomtd *gpiomtd = gpio_nand_getpriv(mtd);

	gpio_nand_dosync(gpiomtd);

	if (ctrl & NAND_CTRL_CHANGE) {
		gpio_set_value(gpiomtd->plat.gpio_nce, !(ctrl & NAND_NCE));
		gpio_set_value(gpiomtd->plat.gpio_cle, !!(ctrl & NAND_CLE));
		gpio_set_value(gpiomtd->plat.gpio_ale, !!(ctrl & NAND_ALE));
		gpio_nand_dosync(gpiomtd);
	}
	if (cmd == NAND_CMD_NONE)
		return;

	writeb(cmd, gpiomtd->nand_chip.IO_ADDR_W);
	gpio_nand_dosync(gpiomtd);
}

static void gpio_nand_writebuf(struct mtd_info *mtd, const u_char *buf, int len)
{
	struct nand_chip *this = mtd->priv;

	writesb(this->IO_ADDR_W, buf, len);
}

static void gpio_nand_readbuf(struct mtd_info *mtd, u_char *buf, int len)
{
	struct nand_chip *this = mtd->priv;

	readsb(this->IO_ADDR_R, buf, len);
}

static int gpio_nand_verifybuf(struct mtd_info *mtd, const u_char *buf, int len)
{
	struct nand_chip *this = mtd->priv;
	unsigned char read, *p = (unsigned char *) buf;
	int i, err = 0;

	for (i = 0; i < len; i++) {
		read = readb(this->IO_ADDR_R);
		if (read != p[i]) {
			pr_debug("%s: err at %d (read %04x vs %04x)\n",
			       __func__, i, read, p[i]);
			err = -EFAULT;
		}
	}
	return err;
}

static void gpio_nand_writebuf16(struct mtd_info *mtd, const u_char *buf,
				 int len)
{
	struct nand_chip *this = mtd->priv;

	if (IS_ALIGNED((unsigned long)buf, 2)) {
		writesw(this->IO_ADDR_W, buf, len>>1);
	} else {
		int i;
		unsigned short *ptr = (unsigned short *)buf;

		for (i = 0; i < len; i += 2, ptr++)
			writew(*ptr, this->IO_ADDR_W);
	}
}

static void gpio_nand_readbuf16(struct mtd_info *mtd, u_char *buf, int len)
{
	struct nand_chip *this = mtd->priv;

	if (IS_ALIGNED((unsigned long)buf, 2)) {
		readsw(this->IO_ADDR_R, buf, len>>1);
	} else {
		int i;
		unsigned short *ptr = (unsigned short *)buf;

		for (i = 0; i < len; i += 2, ptr++)
			*ptr = readw(this->IO_ADDR_R);
	}
}

static int gpio_nand_verifybuf16(struct mtd_info *mtd, const u_char *buf,
				 int len)
{
	struct nand_chip *this = mtd->priv;
	unsigned short read, *p = (unsigned short *) buf;
	int i, err = 0;
	len >>= 1;

	for (i = 0; i < len; i++) {
		read = readw(this->IO_ADDR_R);
		if (read != p[i]) {
			pr_debug("%s: err at %d (read %04x vs %04x)\n",
			       __func__, i, read, p[i]);
			err = -EFAULT;
		}
	}
	return err;
}


static int gpio_nand_devready(struct mtd_info *mtd)
{
	struct gpiomtd *gpiomtd = gpio_nand_getpriv(mtd);
	return gpio_get_value(gpiomtd->plat.gpio_rdy);
}

static int __devexit gpio_nand_remove(struct platform_device *dev)
{
	struct gpiomtd *gpiomtd = platform_get_drvdata(dev);
	struct resource *res;

	nand_release(&gpiomtd->mtd_info);

	res = platform_get_resource(dev, IORESOURCE_MEM, 1);
	iounmap(gpiomtd->io_sync);
	if (res)
		release_mem_region(res->start, resource_size(res));

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	iounmap(gpiomtd->nand_chip.IO_ADDR_R);
	release_mem_region(res->start, resource_size(res));

	if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
		gpio_set_value(gpiomtd->plat.gpio_nwp, 0);
	gpio_set_value(gpiomtd->plat.gpio_nce, 1);

	gpio_free(gpiomtd->plat.gpio_cle);
	gpio_free(gpiomtd->plat.gpio_ale);
	gpio_free(gpiomtd->plat.gpio_nce);
	if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
		gpio_free(gpiomtd->plat.gpio_nwp);
	gpio_free(gpiomtd->plat.gpio_rdy);

	kfree(gpiomtd);

	return 0;
}

static void __iomem *request_and_remap(struct resource *res, size_t size,
					const char *name, int *err)
{
	void __iomem *ptr;

	if (!request_mem_region(res->start, resource_size(res), name)) {
		*err = -EBUSY;
		return NULL;
	}

	ptr = ioremap(res->start, size);
	if (!ptr) {
		release_mem_region(res->start, resource_size(res));
		*err = -ENOMEM;
	}
	return ptr;
}

static int __devinit gpio_nand_probe(struct platform_device *dev)
{
	struct gpiomtd *gpiomtd;
	struct nand_chip *this;
	struct resource *res0, *res1;
	int ret;

	if (!dev->dev.platform_data)
		return -EINVAL;

	res0 = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res0)
		return -EINVAL;

	gpiomtd = kzalloc(sizeof(*gpiomtd), GFP_KERNEL);
	if (gpiomtd == NULL) {
		dev_err(&dev->dev, "failed to create NAND MTD\n");
		return -ENOMEM;
	}

	this = &gpiomtd->nand_chip;
	this->IO_ADDR_R = request_and_remap(res0, 2, "NAND", &ret);
	if (!this->IO_ADDR_R) {
		dev_err(&dev->dev, "unable to map NAND\n");
		goto err_map;
	}

	res1 = platform_get_resource(dev, IORESOURCE_MEM, 1);
	if (res1) {
		gpiomtd->io_sync = request_and_remap(res1, 4, "NAND sync", &ret);
		if (!gpiomtd->io_sync) {
			dev_err(&dev->dev, "unable to map sync NAND\n");
			goto err_sync;
		}
	}

	memcpy(&gpiomtd->plat, dev->dev.platform_data, sizeof(gpiomtd->plat));

	ret = gpio_request(gpiomtd->plat.gpio_nce, "NAND NCE");
	if (ret)
		goto err_nce;
	gpio_direction_output(gpiomtd->plat.gpio_nce, 1);
	if (gpio_is_valid(gpiomtd->plat.gpio_nwp)) {
		ret = gpio_request(gpiomtd->plat.gpio_nwp, "NAND NWP");
		if (ret)
			goto err_nwp;
		gpio_direction_output(gpiomtd->plat.gpio_nwp, 1);
	}
	ret = gpio_request(gpiomtd->plat.gpio_ale, "NAND ALE");
	if (ret)
		goto err_ale;
	gpio_direction_output(gpiomtd->plat.gpio_ale, 0);
	ret = gpio_request(gpiomtd->plat.gpio_cle, "NAND CLE");
	if (ret)
		goto err_cle;
	gpio_direction_output(gpiomtd->plat.gpio_cle, 0);
	ret = gpio_request(gpiomtd->plat.gpio_rdy, "NAND RDY");
	if (ret)
		goto err_rdy;
	gpio_direction_input(gpiomtd->plat.gpio_rdy);


	this->IO_ADDR_W  = this->IO_ADDR_R;
	this->ecc.mode   = NAND_ECC_SOFT;
	this->options    = gpiomtd->plat.options;
	this->chip_delay = gpiomtd->plat.chip_delay;

	/* install our routines */
	this->cmd_ctrl   = gpio_nand_cmd_ctrl;
	this->dev_ready  = gpio_nand_devready;

	if (this->options & NAND_BUSWIDTH_16) {
		this->read_buf   = gpio_nand_readbuf16;
		this->write_buf  = gpio_nand_writebuf16;
		this->verify_buf = gpio_nand_verifybuf16;
	} else {
		this->read_buf   = gpio_nand_readbuf;
		this->write_buf  = gpio_nand_writebuf;
		this->verify_buf = gpio_nand_verifybuf;
	}

	/* set the mtd private data for the nand driver */
	gpiomtd->mtd_info.priv = this;
	gpiomtd->mtd_info.owner = THIS_MODULE;

	if (nand_scan(&gpiomtd->mtd_info, 1)) {
		dev_err(&dev->dev, "no nand chips found?\n");
		ret = -ENXIO;
		goto err_wp;
	}

	if (gpiomtd->plat.adjust_parts)
		gpiomtd->plat.adjust_parts(&gpiomtd->plat,
					   gpiomtd->mtd_info.size);

	add_mtd_partitions(&gpiomtd->mtd_info, gpiomtd->plat.parts,
			   gpiomtd->plat.num_parts);
	platform_set_drvdata(dev, gpiomtd);

	return 0;

err_wp:
	if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
		gpio_set_value(gpiomtd->plat.gpio_nwp, 0);
	gpio_free(gpiomtd->plat.gpio_rdy);
err_rdy:
	gpio_free(gpiomtd->plat.gpio_cle);
err_cle:
	gpio_free(gpiomtd->plat.gpio_ale);
err_ale:
	if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
		gpio_free(gpiomtd->plat.gpio_nwp);
err_nwp:
	gpio_free(gpiomtd->plat.gpio_nce);
err_nce:
	iounmap(gpiomtd->io_sync);
	if (res1)
		release_mem_region(res1->start, resource_size(res1));
err_sync:
	iounmap(gpiomtd->nand_chip.IO_ADDR_R);
	release_mem_region(res0->start, resource_size(res0));
err_map:
	kfree(gpiomtd);
	return ret;
}

static struct platform_driver gpio_nand_driver = {
	.probe		= gpio_nand_probe,
	.remove		= gpio_nand_remove,
	.driver		= {
		.name	= "gpio-nand",
	},
};

static int __init gpio_nand_init(void)
{
	printk(KERN_INFO "GPIO NAND driver, © 2004 Simtec Electronics\n");

	return platform_driver_register(&gpio_nand_driver);
}

static void __exit gpio_nand_exit(void)
{
	platform_driver_unregister(&gpio_nand_driver);
}

module_init(gpio_nand_init);
module_exit(gpio_nand_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_DESCRIPTION("GPIO NAND Driver");
OpenPOWER on IntegriCloud