1/*
  2 * drivers/mtd/maps/ixp2000.c
  3 *
  4 * Mapping for the Intel XScale IXP2000 based systems
  5 *
  6 * Copyright (C) 2002 Intel Corp.
  7 * Copyright (C) 2003-2004 MontaVista Software, Inc.
  8 *
  9 * Original Author: Naeem M Afzal <naeem.m.afzal@intel.com>
 10 * Maintainer: Deepak Saxena <dsaxena@plexity.net>
 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/module.h>
 19#include <linux/types.h>
 20#include <linux/init.h>
 21#include <linux/kernel.h>
 22#include <linux/string.h>
 23#include <linux/slab.h>
 24#include <linux/ioport.h>
 25#include <linux/device.h>
 26#include <linux/platform_device.h>
 27
 28#include <linux/mtd/mtd.h>
 29#include <linux/mtd/map.h>
 30#include <linux/mtd/partitions.h>
 31
 32#include <asm/io.h>
 33#include <mach/hardware.h>
 34#include <asm/mach/flash.h>
 35
 36#include <linux/reboot.h>
 37
 38struct ixp2000_flash_info {
 39	struct		mtd_info *mtd;
 40	struct		map_info map;
 41	struct		mtd_partition *partitions;
 42	struct		resource *res;
 43};
 44
 45static inline unsigned long flash_bank_setup(struct map_info *map, unsigned long ofs)
 46{
 47	unsigned long (*set_bank)(unsigned long) =
 48		(unsigned long(*)(unsigned long))map->map_priv_2;
 49
 50	return (set_bank ? set_bank(ofs) : ofs);
 51}
 52
 53#ifdef __ARMEB__
 54/*
 55 * Rev A0 and A1 of IXP2400 silicon have a broken addressing unit which
 56 * causes the lower address bits to be XORed with 0x11 on 8 bit accesses
 57 * and XORed with 0x10 on 16 bit accesses. See the spec update, erratum 44.
 58 */
 59static int erratum44_workaround = 0;
 60
 61static inline unsigned long address_fix8_write(unsigned long addr)
 62{
 63	if (erratum44_workaround) {
 64		return (addr ^ 3);
 65	}
 66	return addr;
 67}
 68#else
 69
 70#define address_fix8_write(x)	(x)
 71#endif
 72
 73static map_word ixp2000_flash_read8(struct map_info *map, unsigned long ofs)
 74{
 75	map_word val;
 76
 77	val.x[0] =  *((u8 *)(map->map_priv_1 + flash_bank_setup(map, ofs)));
 78	return val;
 79}
 80
 81/*
 82 * We can't use the standard memcpy due to the broken SlowPort
 83 * address translation on rev A0 and A1 silicon and the fact that
 84 * we have banked flash.
 85 */
 86static void ixp2000_flash_copy_from(struct map_info *map, void *to,
 87			      unsigned long from, ssize_t len)
 88{
 89	from = flash_bank_setup(map, from);
 90	while(len--)
 91		*(__u8 *) to++ = *(__u8 *)(map->map_priv_1 + from++);
 92}
 93
 94static void ixp2000_flash_write8(struct map_info *map, map_word d, unsigned long ofs)
 95{
 96	*(__u8 *) (address_fix8_write(map->map_priv_1 +
 97				      flash_bank_setup(map, ofs))) = d.x[0];
 98}
 99
100static void ixp2000_flash_copy_to(struct map_info *map, unsigned long to,
101			    const void *from, ssize_t len)
102{
103	to = flash_bank_setup(map, to);
104	while(len--) {
105		unsigned long tmp = address_fix8_write(map->map_priv_1 + to++);
106		*(__u8 *)(tmp) = *(__u8 *)(from++);
107	}
108}
109
110
111static int ixp2000_flash_remove(struct platform_device *dev)
112{
113	struct flash_platform_data *plat = dev->dev.platform_data;
114	struct ixp2000_flash_info *info = platform_get_drvdata(dev);
115
116	platform_set_drvdata(dev, NULL);
117
118	if(!info)
119		return 0;
120
121	if (info->mtd) {
122		mtd_device_unregister(info->mtd);
123		map_destroy(info->mtd);
124	}
125	if (info->map.map_priv_1)
126		iounmap((void *) info->map.map_priv_1);
127
128	kfree(info->partitions);
129
130	if (info->res) {
131		release_resource(info->res);
132		kfree(info->res);
133	}
134
135	if (plat->exit)
136		plat->exit();
137
138	return 0;
139}
140
141
142static int ixp2000_flash_probe(struct platform_device *dev)
143{
144	static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
145	struct ixp2000_flash_data *ixp_data = dev->dev.platform_data;
146	struct flash_platform_data *plat;
147	struct ixp2000_flash_info *info;
148	unsigned long window_size;
149	int err = -1;
150
151	if (!ixp_data)
152		return -ENODEV;
153
154	plat = ixp_data->platform_data;
155	if (!plat)
156		return -ENODEV;
157
158	window_size = resource_size(dev->resource);
159	dev_info(&dev->dev, "Probe of IXP2000 flash(%d banks x %dMiB)\n",
160		 ixp_data->nr_banks, ((u32)window_size >> 20));
161
162	if (plat->width != 1) {
163		dev_err(&dev->dev, "IXP2000 MTD map only supports 8-bit mode, asking for %d\n",
164			plat->width * 8);
165		return -EIO;
166	}
167
168	info = kzalloc(sizeof(struct ixp2000_flash_info), GFP_KERNEL);
169	if(!info) {
170		err = -ENOMEM;
171		goto Error;
172	}
173
174	platform_set_drvdata(dev, info);
175
176	/*
177	 * Tell the MTD layer we're not 1:1 mapped so that it does
178	 * not attempt to do a direct access on us.
179	 */
180	info->map.phys = NO_XIP;
181
182	info->map.size = ixp_data->nr_banks * window_size;
183	info->map.bankwidth = 1;
184
185	/*
186 	 * map_priv_2 is used to store a ptr to the bank_setup routine
187 	 */
188	info->map.map_priv_2 = (unsigned long) ixp_data->bank_setup;
189
190	info->map.name = dev_name(&dev->dev);
191	info->map.read = ixp2000_flash_read8;
192	info->map.write = ixp2000_flash_write8;
193	info->map.copy_from = ixp2000_flash_copy_from;
194	info->map.copy_to = ixp2000_flash_copy_to;
195
196	info->res = request_mem_region(dev->resource->start,
197				       resource_size(dev->resource),
198				       dev_name(&dev->dev));
199	if (!info->res) {
200		dev_err(&dev->dev, "Could not reserve memory region\n");
201		err = -ENOMEM;
202		goto Error;
203	}
204
205	info->map.map_priv_1 =
206		(unsigned long)ioremap(dev->resource->start,
207				       resource_size(dev->resource));
208	if (!info->map.map_priv_1) {
209		dev_err(&dev->dev, "Failed to ioremap flash region\n");
210		err = -EIO;
211		goto Error;
212	}
213
214#if defined(__ARMEB__)
215	/*
216	 * Enable erratum 44 workaround for NPUs with broken slowport
217	 */
218
219	erratum44_workaround = ixp2000_has_broken_slowport();
220	dev_info(&dev->dev, "Erratum 44 workaround %s\n",
221	       erratum44_workaround ? "enabled" : "disabled");
222#endif
223
224	info->mtd = do_map_probe(plat->map_name, &info->map);
225	if (!info->mtd) {
226		dev_err(&dev->dev, "map_probe failed\n");
227		err = -ENXIO;
228		goto Error;
229	}
230	info->mtd->owner = THIS_MODULE;
231
232	err = parse_mtd_partitions(info->mtd, probes, &info->partitions, 0);
233	if (err > 0) {
234		err = mtd_device_register(info->mtd, info->partitions, err);
235		if(err)
236			dev_err(&dev->dev, "Could not parse partitions\n");
237	}
238
239	if (err)
240		goto Error;
241
242	return 0;
243
244Error:
245	ixp2000_flash_remove(dev);
246	return err;
247}
248
249static struct platform_driver ixp2000_flash_driver = {
250	.probe		= ixp2000_flash_probe,
251	.remove		= ixp2000_flash_remove,
252	.driver		= {
253		.name	= "IXP2000-Flash",
254		.owner	= THIS_MODULE,
255	},
256};
257
258static int __init ixp2000_flash_init(void)
259{
260	return platform_driver_register(&ixp2000_flash_driver);
261}
262
263static void __exit ixp2000_flash_exit(void)
264{
265	platform_driver_unregister(&ixp2000_flash_driver);
266}
267
268module_init(ixp2000_flash_init);
269module_exit(ixp2000_flash_exit);
270MODULE_LICENSE("GPL");
271MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
272MODULE_ALIAS("platform:IXP2000-Flash");