Merge git://git.infradead.org/~dedekind/ubi-2.6
[linux-2.6] / drivers / mtd / nand / at91_nand.c
1 /*
2  * drivers/mtd/nand/at91_nand.c
3  *
4  *  Copyright (C) 2003 Rick Bronson
5  *
6  *  Derived from drivers/mtd/nand/autcpu12.c
7  *       Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
8  *
9  *  Derived from drivers/mtd/spia.c
10  *       Copyright (C) 2000 Steven J. Hill (sjhill@cotw.com)
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  *
16  */
17
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/mtd/mtd.h>
22 #include <linux/mtd/nand.h>
23 #include <linux/mtd/partitions.h>
24
25 #include <asm/io.h>
26 #include <asm/sizes.h>
27
28 #include <asm/hardware.h>
29 #include <asm/arch/board.h>
30 #include <asm/arch/gpio.h>
31
32 struct at91_nand_host {
33         struct nand_chip        nand_chip;
34         struct mtd_info         mtd;
35         void __iomem            *io_base;
36         struct at91_nand_data   *board;
37 };
38
39 /*
40  * Hardware specific access to control-lines
41  */
42 static void at91_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
43 {
44         struct nand_chip *nand_chip = mtd->priv;
45         struct at91_nand_host *host = nand_chip->priv;
46
47         if (cmd == NAND_CMD_NONE)
48                 return;
49
50         if (ctrl & NAND_CLE)
51                 writeb(cmd, host->io_base + (1 << host->board->cle));
52         else
53                 writeb(cmd, host->io_base + (1 << host->board->ale));
54 }
55
56 /*
57  * Read the Device Ready pin.
58  */
59 static int at91_nand_device_ready(struct mtd_info *mtd)
60 {
61         struct nand_chip *nand_chip = mtd->priv;
62         struct at91_nand_host *host = nand_chip->priv;
63
64         return at91_get_gpio_value(host->board->rdy_pin);
65 }
66
67 /*
68  * Enable NAND.
69  */
70 static void at91_nand_enable(struct at91_nand_host *host)
71 {
72         if (host->board->enable_pin)
73                 at91_set_gpio_value(host->board->enable_pin, 0);
74 }
75
76 /*
77  * Disable NAND.
78  */
79 static void at91_nand_disable(struct at91_nand_host *host)
80 {
81         if (host->board->enable_pin)
82                 at91_set_gpio_value(host->board->enable_pin, 1);
83 }
84
85 #ifdef CONFIG_MTD_PARTITIONS
86 const char *part_probes[] = { "cmdlinepart", NULL };
87 #endif
88
89 /*
90  * Probe for the NAND device.
91  */
92 static int __init at91_nand_probe(struct platform_device *pdev)
93 {
94         struct at91_nand_host *host;
95         struct mtd_info *mtd;
96         struct nand_chip *nand_chip;
97         int res;
98
99 #ifdef CONFIG_MTD_PARTITIONS
100         struct mtd_partition *partitions = NULL;
101         int num_partitions = 0;
102 #endif
103
104         /* Allocate memory for the device structure (and zero it) */
105         host = kzalloc(sizeof(struct at91_nand_host), GFP_KERNEL);
106         if (!host) {
107                 printk(KERN_ERR "at91_nand: failed to allocate device structure.\n");
108                 return -ENOMEM;
109         }
110
111         host->io_base = ioremap(pdev->resource[0].start,
112                                 pdev->resource[0].end - pdev->resource[0].start + 1);
113         if (host->io_base == NULL) {
114                 printk(KERN_ERR "at91_nand: ioremap failed\n");
115                 kfree(host);
116                 return -EIO;
117         }
118
119         mtd = &host->mtd;
120         nand_chip = &host->nand_chip;
121         host->board = pdev->dev.platform_data;
122
123         nand_chip->priv = host;         /* link the private data structures */
124         mtd->priv = nand_chip;
125         mtd->owner = THIS_MODULE;
126
127         /* Set address of NAND IO lines */
128         nand_chip->IO_ADDR_R = host->io_base;
129         nand_chip->IO_ADDR_W = host->io_base;
130         nand_chip->cmd_ctrl = at91_nand_cmd_ctrl;
131
132         if (host->board->rdy_pin)
133                 nand_chip->dev_ready = at91_nand_device_ready;
134
135         nand_chip->ecc.mode = NAND_ECC_SOFT;    /* enable ECC */
136         nand_chip->chip_delay = 20;             /* 20us command delay time */
137
138         if (host->board->bus_width_16)          /* 16-bit bus width */
139                 nand_chip->options |= NAND_BUSWIDTH_16;
140
141         platform_set_drvdata(pdev, host);
142         at91_nand_enable(host);
143
144         if (host->board->det_pin) {
145                 if (at91_get_gpio_value(host->board->det_pin)) {
146                         printk ("No SmartMedia card inserted.\n");
147                         res = ENXIO;
148                         goto out;
149                 }
150         }
151
152         /* Scan to find existance of the device */
153         if (nand_scan(mtd, 1)) {
154                 res = -ENXIO;
155                 goto out;
156         }
157
158 #ifdef CONFIG_MTD_PARTITIONS
159 #ifdef CONFIG_MTD_CMDLINE_PARTS
160         mtd->name = "at91_nand";
161         num_partitions = parse_mtd_partitions(mtd, part_probes,
162                                               &partitions, 0);
163 #endif
164         if (num_partitions <= 0 && host->board->partition_info)
165                 partitions = host->board->partition_info(mtd->size,
166                                                          &num_partitions);
167
168         if ((!partitions) || (num_partitions == 0)) {
169                 printk(KERN_ERR "at91_nand: No parititions defined, or unsupported device.\n");
170                 res = ENXIO;
171                 goto release;
172         }
173
174         res = add_mtd_partitions(mtd, partitions, num_partitions);
175 #else
176         res = add_mtd_device(mtd);
177 #endif
178
179         if (!res)
180                 return res;
181
182 release:
183         nand_release(mtd);
184 out:
185         at91_nand_disable(host);
186         platform_set_drvdata(pdev, NULL);
187         iounmap(host->io_base);
188         kfree(host);
189         return res;
190 }
191
192 /*
193  * Remove a NAND device.
194  */
195 static int __devexit at91_nand_remove(struct platform_device *pdev)
196 {
197         struct at91_nand_host *host = platform_get_drvdata(pdev);
198         struct mtd_info *mtd = &host->mtd;
199
200         nand_release(mtd);
201
202         at91_nand_disable(host);
203
204         iounmap(host->io_base);
205         kfree(host);
206
207         return 0;
208 }
209
210 static struct platform_driver at91_nand_driver = {
211         .probe          = at91_nand_probe,
212         .remove         = at91_nand_remove,
213         .driver         = {
214                 .name   = "at91_nand",
215                 .owner  = THIS_MODULE,
216         },
217 };
218
219 static int __init at91_nand_init(void)
220 {
221         return platform_driver_register(&at91_nand_driver);
222 }
223
224
225 static void __exit at91_nand_exit(void)
226 {
227         platform_driver_unregister(&at91_nand_driver);
228 }
229
230
231 module_init(at91_nand_init);
232 module_exit(at91_nand_exit);
233
234 MODULE_LICENSE("GPL");
235 MODULE_AUTHOR("Rick Bronson");
236 MODULE_DESCRIPTION("NAND/SmartMedia driver for AT91RM9200");