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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 
38 struct ixp2000_flash_info {
39 	struct		mtd_info *mtd;
40 	struct		map_info map;
41 	struct		mtd_partition *partitions;
42 	struct		resource *res;
43 };
44 
flash_bank_setup(struct map_info * map,unsigned long ofs)45 static 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  */
59 static int erratum44_workaround = 0;
60 
address_fix8_write(unsigned long addr)61 static 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 
ixp2000_flash_read8(struct map_info * map,unsigned long ofs)73 static 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  */
ixp2000_flash_copy_from(struct map_info * map,void * to,unsigned long from,ssize_t len)86 static 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 
ixp2000_flash_write8(struct map_info * map,map_word d,unsigned long ofs)94 static 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 
ixp2000_flash_copy_to(struct map_info * map,unsigned long to,const void * from,ssize_t len)100 static 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 
ixp2000_flash_remove(struct platform_device * dev)111 static 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 		del_mtd_partitions(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 
ixp2000_flash_probe(struct platform_device * dev)142 static 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 = dev->resource->end - dev->resource->start + 1;
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 = kmalloc(sizeof(struct ixp2000_flash_info), GFP_KERNEL);
169 	if(!info) {
170 		err = -ENOMEM;
171 		goto Error;
172 	}
173 	memset(info, 0, sizeof(struct ixp2000_flash_info));
174 
175 	platform_set_drvdata(dev, info);
176 
177 	/*
178 	 * Tell the MTD layer we're not 1:1 mapped so that it does
179 	 * not attempt to do a direct access on us.
180 	 */
181 	info->map.phys = NO_XIP;
182 
183 	info->map.size = ixp_data->nr_banks * window_size;
184 	info->map.bankwidth = 1;
185 
186 	/*
187  	 * map_priv_2 is used to store a ptr to to the bank_setup routine
188  	 */
189 	info->map.map_priv_2 = (unsigned long) ixp_data->bank_setup;
190 
191 	info->map.name = dev_name(&dev->dev);
192 	info->map.read = ixp2000_flash_read8;
193 	info->map.write = ixp2000_flash_write8;
194 	info->map.copy_from = ixp2000_flash_copy_from;
195 	info->map.copy_to = ixp2000_flash_copy_to;
196 
197 	info->res = request_mem_region(dev->resource->start,
198 			dev->resource->end - dev->resource->start + 1,
199 			dev_name(&dev->dev));
200 	if (!info->res) {
201 		dev_err(&dev->dev, "Could not reserve memory region\n");
202 		err = -ENOMEM;
203 		goto Error;
204 	}
205 
206 	info->map.map_priv_1 = (unsigned long) ioremap(dev->resource->start,
207 			    	dev->resource->end - dev->resource->start + 1);
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 = add_mtd_partitions(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 
244 Error:
245 	ixp2000_flash_remove(dev);
246 	return err;
247 }
248 
249 static 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 
ixp2000_flash_init(void)258 static int __init ixp2000_flash_init(void)
259 {
260 	return platform_driver_register(&ixp2000_flash_driver);
261 }
262 
ixp2000_flash_exit(void)263 static void __exit ixp2000_flash_exit(void)
264 {
265 	platform_driver_unregister(&ixp2000_flash_driver);
266 }
267 
268 module_init(ixp2000_flash_init);
269 module_exit(ixp2000_flash_exit);
270 MODULE_LICENSE("GPL");
271 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
272 MODULE_ALIAS("platform:IXP2000-Flash");
273