Merge branch 'topic/cleanup' into for-linus
[linux-2.6] / drivers / mtd / nand / socrates_nand.c
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
158 #ifdef CONFIG_MTD_PARTITIONS
159 static const char *part_probes[] = { "cmdlinepart", NULL };
160 #endif
161
162 /*
163  * Probe for the NAND device.
164  */
165 static int __devinit socrates_nand_probe(struct of_device *ofdev,
166                                          const struct of_device_id *ofid)
167 {
168         struct socrates_nand_host *host;
169         struct mtd_info *mtd;
170         struct nand_chip *nand_chip;
171         int res;
172
173 #ifdef CONFIG_MTD_PARTITIONS
174         struct mtd_partition *partitions = NULL;
175         int num_partitions = 0;
176 #endif
177
178         /* Allocate memory for the device structure (and zero it) */
179         host = kzalloc(sizeof(struct socrates_nand_host), GFP_KERNEL);
180         if (!host) {
181                 printk(KERN_ERR
182                        "socrates_nand: failed to allocate device structure.\n");
183                 return -ENOMEM;
184         }
185
186         host->io_base = of_iomap(ofdev->node, 0);
187         if (host->io_base == NULL) {
188                 printk(KERN_ERR "socrates_nand: ioremap failed\n");
189                 kfree(host);
190                 return -EIO;
191         }
192
193         mtd = &host->mtd;
194         nand_chip = &host->nand_chip;
195         host->dev = &ofdev->dev;
196
197         nand_chip->priv = host;         /* link the private data structures */
198         mtd->priv = nand_chip;
199         mtd->name = "socrates_nand";
200         mtd->owner = THIS_MODULE;
201         mtd->dev.parent = &ofdev->dev;
202
203         /*should never be accessed directly */
204         nand_chip->IO_ADDR_R = (void *)0xdeadbeef;
205         nand_chip->IO_ADDR_W = (void *)0xdeadbeef;
206
207         nand_chip->cmd_ctrl = socrates_nand_cmd_ctrl;
208         nand_chip->read_byte = socrates_nand_read_byte;
209         nand_chip->read_word = socrates_nand_read_word;
210         nand_chip->write_buf = socrates_nand_write_buf;
211         nand_chip->read_buf = socrates_nand_read_buf;
212         nand_chip->verify_buf = socrates_nand_verify_buf;
213         nand_chip->dev_ready = socrates_nand_device_ready;
214
215         nand_chip->ecc.mode = NAND_ECC_SOFT;    /* enable ECC */
216
217         /* TODO: I have no idea what real delay is. */
218         nand_chip->chip_delay = 20;             /* 20us command delay time */
219
220         dev_set_drvdata(&ofdev->dev, host);
221
222         /* first scan to find the device and get the page size */
223         if (nand_scan_ident(mtd, 1)) {
224                 res = -ENXIO;
225                 goto out;
226         }
227
228         /* second phase scan */
229         if (nand_scan_tail(mtd)) {
230                 res = -ENXIO;
231                 goto out;
232         }
233
234 #ifdef CONFIG_MTD_PARTITIONS
235 #ifdef CONFIG_MTD_CMDLINE_PARTS
236         num_partitions = parse_mtd_partitions(mtd, part_probes,
237                                               &partitions, 0);
238         if (num_partitions < 0) {
239                 res = num_partitions;
240                 goto release;
241         }
242 #endif
243
244 #ifdef CONFIG_MTD_OF_PARTS
245         if (num_partitions == 0) {
246                 num_partitions = of_mtd_parse_partitions(&ofdev->dev,
247                                                          ofdev->node,
248                                                          &partitions);
249                 if (num_partitions < 0) {
250                         res = num_partitions;
251                         goto release;
252                 }
253         }
254 #endif
255         if (partitions && (num_partitions > 0))
256                 res = add_mtd_partitions(mtd, partitions, num_partitions);
257         else
258 #endif
259                 res = add_mtd_device(mtd);
260
261         if (!res)
262                 return res;
263
264 #ifdef CONFIG_MTD_PARTITIONS
265 release:
266 #endif
267         nand_release(mtd);
268
269 out:
270         dev_set_drvdata(&ofdev->dev, NULL);
271         iounmap(host->io_base);
272         kfree(host);
273         return res;
274 }
275
276 /*
277  * Remove a NAND device.
278  */
279 static int __devexit socrates_nand_remove(struct of_device *ofdev)
280 {
281         struct socrates_nand_host *host = dev_get_drvdata(&ofdev->dev);
282         struct mtd_info *mtd = &host->mtd;
283
284         nand_release(mtd);
285
286         dev_set_drvdata(&ofdev->dev, NULL);
287         iounmap(host->io_base);
288         kfree(host);
289
290         return 0;
291 }
292
293 static struct of_device_id socrates_nand_match[] =
294 {
295         {
296                 .compatible   = "abb,socrates-nand",
297         },
298         {},
299 };
300
301 MODULE_DEVICE_TABLE(of, socrates_nand_match);
302
303 static struct of_platform_driver socrates_nand_driver = {
304         .name           = "socrates_nand",
305         .match_table    = socrates_nand_match,
306         .probe          = socrates_nand_probe,
307         .remove         = __devexit_p(socrates_nand_remove),
308 };
309
310 static int __init socrates_nand_init(void)
311 {
312         return of_register_platform_driver(&socrates_nand_driver);
313 }
314
315 static void __exit socrates_nand_exit(void)
316 {
317         of_unregister_platform_driver(&socrates_nand_driver);
318 }
319
320 module_init(socrates_nand_init);
321 module_exit(socrates_nand_exit);
322
323 MODULE_LICENSE("GPL");
324 MODULE_AUTHOR("Ilya Yanok");
325 MODULE_DESCRIPTION("NAND driver for Socrates board");