1/*
2 * $Id: ixp2000.c,v 1.1.1.1 2007/08/03 18:52:43 Exp $
3 *
4 * drivers/mtd/maps/ixp2000.c
5 *
6 * Mapping for the Intel XScale IXP2000 based systems
7 *
8 * Copyright (C) 2002 Intel Corp.
9 * Copyright (C) 2003-2004 MontaVista Software, Inc.
10 *
11 * Original Author: Naeem M Afzal <naeem.m.afzal@intel.com>
12 * Maintainer: Deepak Saxena <dsaxena@plexity.net>
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License version 2 as
16 * published by the Free Software Foundation.
17 *
18 */
19
20#include <linux/module.h>
21#include <linux/types.h>
22#include <linux/init.h>
23#include <linux/kernel.h>
24#include <linux/string.h>
25#include <linux/slab.h>
26#include <linux/ioport.h>
27#include <linux/device.h>
28#include <linux/platform_device.h>
29
30#include <linux/mtd/mtd.h>
31#include <linux/mtd/map.h>
32#include <linux/mtd/partitions.h>
33
34#include <asm/io.h>
35#include <asm/hardware.h>
36#include <asm/mach/flash.h>
37
38#include <linux/reboot.h>
39
40struct ixp2000_flash_info {
41	struct		mtd_info *mtd;
42	struct		map_info map;
43	struct		mtd_partition *partitions;
44	struct		resource *res;
45};
46
47static inline unsigned long flash_bank_setup(struct map_info *map, unsigned long ofs)
48{
49	unsigned long (*set_bank)(unsigned long) =
50		(unsigned long(*)(unsigned long))map->map_priv_2;
51
52	return (set_bank ? set_bank(ofs) : ofs);
53}
54
55#ifdef __ARMEB__
56/*
57 * Rev A0 and A1 of IXP2400 silicon have a broken addressing unit which
58 * causes the lower address bits to be XORed with 0x11 on 8 bit accesses
59 * and XORed with 0x10 on 16 bit accesses. See the spec update, erratum 44.
60 */
61static int erratum44_workaround = 0;
62
63static inline unsigned long address_fix8_write(unsigned long addr)
64{
65	if (erratum44_workaround) {
66		return (addr ^ 3);
67	}
68	return addr;
69}
70#else
71
72#define address_fix8_write(x)	(x)
73#endif
74
75static map_word ixp2000_flash_read8(struct map_info *map, unsigned long ofs)
76{
77	map_word val;
78
79	val.x[0] =  *((u8 *)(map->map_priv_1 + flash_bank_setup(map, ofs)));
80	return val;
81}
82
83/*
84 * We can't use the standard memcpy due to the broken SlowPort
85 * address translation on rev A0 and A1 silicon and the fact that
86 * we have banked flash.
87 */
88static void ixp2000_flash_copy_from(struct map_info *map, void *to,
89			      unsigned long from, ssize_t len)
90{
91	from = flash_bank_setup(map, from);
92	while(len--)
93		*(__u8 *) to++ = *(__u8 *)(map->map_priv_1 + from++);
94}
95
96static void ixp2000_flash_write8(struct map_info *map, map_word d, unsigned long ofs)
97{
98	*(__u8 *) (address_fix8_write(map->map_priv_1 +
99				      flash_bank_setup(map, ofs))) = d.x[0];
100}
101
102static void ixp2000_flash_copy_to(struct map_info *map, unsigned long to,
103			    const void *from, ssize_t len)
104{
105	to = flash_bank_setup(map, to);
106	while(len--) {
107		unsigned long tmp = address_fix8_write(map->map_priv_1 + to++);
108		*(__u8 *)(tmp) = *(__u8 *)(from++);
109	}
110}
111
112
113static int ixp2000_flash_remove(struct platform_device *dev)
114{
115	struct flash_platform_data *plat = dev->dev.platform_data;
116	struct ixp2000_flash_info *info = platform_get_drvdata(dev);
117
118	platform_set_drvdata(dev, NULL);
119
120	if(!info)
121		return 0;
122
123	if (info->mtd) {
124		del_mtd_partitions(info->mtd);
125		map_destroy(info->mtd);
126	}
127	if (info->map.map_priv_1)
128		iounmap((void *) info->map.map_priv_1);
129
130	kfree(info->partitions);
131
132	if (info->res) {
133		release_resource(info->res);
134		kfree(info->res);
135	}
136
137	if (plat->exit)
138		plat->exit();
139
140	return 0;
141}
142
143
144static int ixp2000_flash_probe(struct platform_device *dev)
145{
146	static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
147	struct ixp2000_flash_data *ixp_data = dev->dev.platform_data;
148	struct flash_platform_data *plat;
149	struct ixp2000_flash_info *info;
150	unsigned long window_size;
151	int err = -1;
152
153	if (!ixp_data)
154		return -ENODEV;
155
156	plat = ixp_data->platform_data;
157	if (!plat)
158		return -ENODEV;
159
160	window_size = dev->resource->end - dev->resource->start + 1;
161	dev_info(&dev->dev, "Probe of IXP2000 flash(%d banks x %dMiB)\n",
162		 ixp_data->nr_banks, ((u32)window_size >> 20));
163
164	if (plat->width != 1) {
165		dev_err(&dev->dev, "IXP2000 MTD map only supports 8-bit mode, asking for %d\n",
166			plat->width * 8);
167		return -EIO;
168	}
169
170	info = kmalloc(sizeof(struct ixp2000_flash_info), GFP_KERNEL);
171	if(!info) {
172		err = -ENOMEM;
173		goto Error;
174	}
175	memzero(info, sizeof(struct ixp2000_flash_info));
176
177	platform_set_drvdata(dev, info);
178
179	/*
180	 * Tell the MTD layer we're not 1:1 mapped so that it does
181	 * not attempt to do a direct access on us.
182	 */
183	info->map.phys = NO_XIP;
184
185	info->map.size = ixp_data->nr_banks * window_size;
186	info->map.bankwidth = 1;
187
188	/*
189 	 * map_priv_2 is used to store a ptr to to the bank_setup routine
190 	 */
191	info->map.map_priv_2 = (unsigned long) ixp_data->bank_setup;
192
193	info->map.name = dev->dev.bus_id;
194	info->map.read = ixp2000_flash_read8;
195	info->map.write = ixp2000_flash_write8;
196	info->map.copy_from = ixp2000_flash_copy_from;
197	info->map.copy_to = ixp2000_flash_copy_to;
198
199	info->res = request_mem_region(dev->resource->start,
200			dev->resource->end - dev->resource->start + 1,
201			dev->dev.bus_id);
202	if (!info->res) {
203		dev_err(&dev->dev, "Could not reserve memory region\n");
204		err = -ENOMEM;
205		goto Error;
206	}
207
208	info->map.map_priv_1 = (unsigned long) ioremap(dev->resource->start,
209			    	dev->resource->end - dev->resource->start + 1);
210	if (!info->map.map_priv_1) {
211		dev_err(&dev->dev, "Failed to ioremap flash region\n");
212		err = -EIO;
213		goto Error;
214	}
215
216#if defined(__ARMEB__)
217
218	erratum44_workaround = ixp2000_has_broken_slowport();
219	dev_info(&dev->dev, "Erratum 44 workaround %s\n",
220	       erratum44_workaround ? "enabled" : "disabled");
221#endif
222
223	info->mtd = do_map_probe(plat->map_name, &info->map);
224	if (!info->mtd) {
225		dev_err(&dev->dev, "map_probe failed\n");
226		err = -ENXIO;
227		goto Error;
228	}
229	info->mtd->owner = THIS_MODULE;
230
231	err = parse_mtd_partitions(info->mtd, probes, &info->partitions, 0);
232	if (err > 0) {
233		err = add_mtd_partitions(info->mtd, info->partitions, err);
234		if(err)
235			dev_err(&dev->dev, "Could not parse partitions\n");
236	}
237
238	if (err)
239		goto Error;
240
241	return 0;
242
243Error:
244	ixp2000_flash_remove(dev);
245	return err;
246}
247
248static struct platform_driver ixp2000_flash_driver = {
249	.probe		= ixp2000_flash_probe,
250	.remove		= ixp2000_flash_remove,
251	.driver		= {
252		.name	= "IXP2000-Flash",
253	},
254};
255
256static int __init ixp2000_flash_init(void)
257{
258	return platform_driver_register(&ixp2000_flash_driver);
259}
260
261static void __exit ixp2000_flash_exit(void)
262{
263	platform_driver_unregister(&ixp2000_flash_driver);
264}
265
266module_init(ixp2000_flash_init);
267module_exit(ixp2000_flash_exit);
268MODULE_LICENSE("GPL");
269MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
270