1/*
2*  Copyright (C) 2005 - 2007 by Basler Vision Technologies AG
3*  Author: Thomas Koeller <thomas.koeller.qbaslerweb.com>
4*  Original code by Thies Moeller <thies.moeller@baslerweb.com>
5*
6*  This program is free software; you can redistribute it and/or modify
7*  it under the terms of the GNU General Public License as published by
8*  the Free Software Foundation; either version 2 of the License, or
9*  (at your option) any later version.
10*
11*  This program is distributed in the hope that it will be useful,
12*  but WITHOUT ANY WARRANTY; without even the implied warranty of
13*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14*  GNU General Public License for more details.
15*
16*  You should have received a copy of the GNU General Public License
17*  along with this program; if not, write to the Free Software
18*  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19*/
20
21#include <linux/module.h>
22#include <linux/types.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/string.h>
26#include <linux/ioport.h>
27#include <linux/platform_device.h>
28#include <linux/delay.h>
29#include <linux/err.h>
30#include <linux/kernel.h>
31
32#include <linux/mtd/mtd.h>
33#include <linux/mtd/nand.h>
34#include <linux/mtd/nand_ecc.h>
35#include <linux/mtd/partitions.h>
36
37#include <asm/io.h>
38#include <asm/rm9k-ocd.h>
39
40#include <excite_nandflash.h>
41
42#define EXCITE_NANDFLASH_VERSION "0.1"
43
44/* I/O register offsets */
45#define EXCITE_NANDFLASH_DATA_BYTE   0x00
46#define EXCITE_NANDFLASH_STATUS_BYTE 0x0c
47#define EXCITE_NANDFLASH_ADDR_BYTE   0x10
48#define EXCITE_NANDFLASH_CMD_BYTE    0x14
49
50/* prefix for debug output */
51static const char module_id[] = "excite_nandflash";
52
53/*
54 * partition definition
55 */
56static const struct mtd_partition partition_info[] = {
57	{
58		.name = "eXcite RootFS",
59		.offset = 0,
60		.size = MTDPART_SIZ_FULL
61	}
62};
63
64static inline const struct resource *
65excite_nand_get_resource(struct platform_device *d, unsigned long flags,
66			 const char *basename)
67{
68	char buf[80];
69
70	if (snprintf(buf, sizeof buf, "%s_%u", basename, d->id) >= sizeof buf)
71		return NULL;
72	return platform_get_resource_byname(d, flags, buf);
73}
74
75static inline void __iomem *
76excite_nand_map_regs(struct platform_device *d, const char *basename)
77{
78	void *result = NULL;
79	const struct resource *const r =
80	    excite_nand_get_resource(d, IORESOURCE_MEM, basename);
81
82	if (r)
83		result = ioremap_nocache(r->start, r->end + 1 - r->start);
84	return result;
85}
86
87/* controller and mtd information */
88struct excite_nand_drvdata {
89	struct mtd_info board_mtd;
90	struct nand_chip board_chip;
91	void __iomem *regs;
92	void __iomem *tgt;
93};
94
95/* Control function */
96static void excite_nand_control(struct mtd_info *mtd, int cmd,
97				       unsigned int ctrl)
98{
99	struct excite_nand_drvdata * const d =
100	    container_of(mtd, struct excite_nand_drvdata, board_mtd);
101
102	switch (ctrl) {
103	case NAND_CTRL_CHANGE | NAND_CTRL_CLE:
104		d->tgt = d->regs + EXCITE_NANDFLASH_CMD_BYTE;
105		break;
106	case NAND_CTRL_CHANGE | NAND_CTRL_ALE:
107		d->tgt = d->regs + EXCITE_NANDFLASH_ADDR_BYTE;
108		break;
109	case NAND_CTRL_CHANGE | NAND_NCE:
110		d->tgt = d->regs + EXCITE_NANDFLASH_DATA_BYTE;
111		break;
112	}
113
114	if (cmd != NAND_CMD_NONE)
115		__raw_writeb(cmd, d->tgt);
116}
117
118/* Return 0 if flash is busy, 1 if ready */
119static int excite_nand_devready(struct mtd_info *mtd)
120{
121	struct excite_nand_drvdata * const drvdata =
122	    container_of(mtd, struct excite_nand_drvdata, board_mtd);
123
124	return __raw_readb(drvdata->regs + EXCITE_NANDFLASH_STATUS_BYTE);
125}
126
127/*
128 * Called by device layer to remove the driver.
129 * The binding to the mtd and all allocated
130 * resources are released.
131 */
132static int __exit excite_nand_remove(struct device *dev)
133{
134	struct excite_nand_drvdata * const this = dev_get_drvdata(dev);
135
136	dev_set_drvdata(dev, NULL);
137
138	if (unlikely(!this)) {
139		printk(KERN_ERR "%s: called %s without private data!!",
140		       module_id, __func__);
141		return -EINVAL;
142	}
143
144	/* first thing we need to do is release our mtd
145	 * then go through freeing the resource used
146	 */
147	nand_release(&this->board_mtd);
148
149	/* free the common resources */
150	iounmap(this->regs);
151	kfree(this);
152
153	DEBUG(MTD_DEBUG_LEVEL1, "%s: removed\n", module_id);
154	return 0;
155}
156
157/*
158 * Called by device layer when it finds a device matching
159 * one our driver can handle. This code checks to see if
160 * it can allocate all necessary resources then calls the
161 * nand layer to look for devices.
162*/
163static int __init excite_nand_probe(struct device *dev)
164{
165	struct platform_device * const pdev = to_platform_device(dev);
166	struct excite_nand_drvdata *drvdata;	/* private driver data */
167	struct nand_chip *board_chip;	/* private flash chip data */
168	struct mtd_info *board_mtd;	/* mtd info for this board */
169	int scan_res;
170
171	drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
172	if (unlikely(!drvdata)) {
173		printk(KERN_ERR "%s: no memory for drvdata\n",
174		       module_id);
175		return -ENOMEM;
176	}
177
178	/* bind private data into driver */
179	dev_set_drvdata(dev, drvdata);
180
181	/* allocate and map the resource */
182	drvdata->regs =
183		excite_nand_map_regs(pdev, EXCITE_NANDFLASH_RESOURCE_REGS);
184
185	if (unlikely(!drvdata->regs)) {
186		printk(KERN_ERR "%s: cannot reserve register region\n",
187		       module_id);
188		kfree(drvdata);
189		return -ENXIO;
190	}
191
192	drvdata->tgt = drvdata->regs + EXCITE_NANDFLASH_DATA_BYTE;
193
194	/* initialise our chip */
195	board_chip = &drvdata->board_chip;
196	board_chip->IO_ADDR_R = board_chip->IO_ADDR_W =
197		drvdata->regs + EXCITE_NANDFLASH_DATA_BYTE;
198	board_chip->cmd_ctrl = excite_nand_control;
199	board_chip->dev_ready = excite_nand_devready;
200	board_chip->chip_delay = 25;
201	board_chip->ecc.mode = NAND_ECC_SOFT;
202
203	/* link chip to mtd */
204	board_mtd = &drvdata->board_mtd;
205	board_mtd->priv = board_chip;
206
207	DEBUG(MTD_DEBUG_LEVEL2, "%s: device scan\n", module_id);
208	scan_res = nand_scan(&drvdata->board_mtd, 1);
209
210	if (likely(!scan_res)) {
211		DEBUG(MTD_DEBUG_LEVEL2, "%s: register partitions\n", module_id);
212		add_mtd_partitions(&drvdata->board_mtd, partition_info,
213				   sizeof partition_info / sizeof partition_info[0]);
214	} else {
215		iounmap(drvdata->regs);
216		kfree(drvdata);
217		printk(KERN_ERR "%s: device scan failed\n", module_id);
218		return -EIO;
219	}
220	return 0;
221}
222
223static struct device_driver excite_nand_driver = {
224	.name = "excite_nand",
225	.bus = &platform_bus_type,
226	.probe = excite_nand_probe,
227	.remove = __exit_p(excite_nand_remove)
228};
229
230static int __init excite_nand_init(void)
231{
232	pr_info("Basler eXcite nand flash driver Version "
233		EXCITE_NANDFLASH_VERSION "\n");
234	return driver_register(&excite_nand_driver);
235}
236
237static void __exit excite_nand_exit(void)
238{
239	driver_unregister(&excite_nand_driver);
240}
241
242module_init(excite_nand_init);
243module_exit(excite_nand_exit);
244
245MODULE_AUTHOR("Thomas Koeller <thomas.koeller@baslerweb.com>");
246MODULE_DESCRIPTION("Basler eXcite NAND-Flash driver");
247MODULE_LICENSE("GPL");
248MODULE_VERSION(EXCITE_NANDFLASH_VERSION)
249