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
32struct 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 */
42static 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 */
59static 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 */
70static 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 */
79static 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
86const char *part_probes[] = { "cmdlinepart", NULL };
87#endif
88
89/*
90 * Probe for the NAND device.
91 */
92static 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	nand_chip->dev_ready = at91_nand_device_ready;
132	nand_chip->ecc.mode = NAND_ECC_SOFT;	/* enable ECC */
133	nand_chip->chip_delay = 20;		/* 20us command delay time */
134
135	if (host->board->bus_width_16)		/* 16-bit bus width */
136		nand_chip->options |= NAND_BUSWIDTH_16;
137
138	platform_set_drvdata(pdev, host);
139	at91_nand_enable(host);
140
141	if (host->board->det_pin) {
142		if (at91_get_gpio_value(host->board->det_pin)) {
143			printk ("No SmartMedia card inserted.\n");
144			res = ENXIO;
145			goto out;
146		}
147	}
148
149	/* Scan to find existance of the device */
150	if (nand_scan(mtd, 1)) {
151		res = -ENXIO;
152		goto out;
153	}
154
155#ifdef CONFIG_MTD_PARTITIONS
156	if (host->board->partition_info)
157		partitions = host->board->partition_info(mtd->size, &num_partitions);
158#ifdef CONFIG_MTD_CMDLINE_PARTS
159	else {
160		mtd->name = "at91_nand";
161		num_partitions = parse_mtd_partitions(mtd, part_probes, &partitions, 0);
162	}
163#endif
164
165	if ((!partitions) || (num_partitions == 0)) {
166		printk(KERN_ERR "at91_nand: No parititions defined, or unsupported device.\n");
167		res = ENXIO;
168		goto release;
169	}
170
171	res = add_mtd_partitions(mtd, partitions, num_partitions);
172#else
173	res = add_mtd_device(mtd);
174#endif
175
176	if (!res)
177		return res;
178
179release:
180	nand_release(mtd);
181out:
182	at91_nand_disable(host);
183	platform_set_drvdata(pdev, NULL);
184	iounmap(host->io_base);
185	kfree(host);
186	return res;
187}
188
189/*
190 * Remove a NAND device.
191 */
192static int __devexit at91_nand_remove(struct platform_device *pdev)
193{
194	struct at91_nand_host *host = platform_get_drvdata(pdev);
195	struct mtd_info *mtd = &host->mtd;
196
197	nand_release(mtd);
198
199	at91_nand_disable(host);
200
201	iounmap(host->io_base);
202	kfree(host);
203
204	return 0;
205}
206
207static struct platform_driver at91_nand_driver = {
208	.probe		= at91_nand_probe,
209	.remove		= at91_nand_remove,
210	.driver		= {
211		.name	= "at91_nand",
212		.owner	= THIS_MODULE,
213	},
214};
215
216static int __init at91_nand_init(void)
217{
218	return platform_driver_register(&at91_nand_driver);
219}
220
221
222static void __exit at91_nand_exit(void)
223{
224	platform_driver_unregister(&at91_nand_driver);
225}
226
227
228module_init(at91_nand_init);
229module_exit(at91_nand_exit);
230
231MODULE_LICENSE("GPL");
232MODULE_AUTHOR("Rick Bronson");
233MODULE_DESCRIPTION("NAND/SmartMedia driver for AT91RM9200");
234