Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...
[linux-2.6] / drivers / mtd / maps / dc21285.c
1 /*
2  * MTD map driver for flash on the DC21285 (the StrongARM-110 companion chip)
3  *
4  * (C) 2000  Nicolas Pitre <nico@cam.org>
5  *
6  * This code is GPL
7  * 
8  * $Id: dc21285.c,v 1.22 2004/11/01 13:39:21 rmk Exp $
9  */
10 #include <linux/config.h>
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/delay.h>
16 #include <linux/slab.h>
17
18 #include <linux/mtd/mtd.h>
19 #include <linux/mtd/map.h>
20 #include <linux/mtd/partitions.h>
21
22 #include <asm/io.h>
23 #include <asm/hardware/dec21285.h>
24 #include <asm/mach-types.h>
25
26
27 static struct mtd_info *dc21285_mtd;
28
29 #ifdef CONFIG_ARCH_NETWINDER
30 /* 
31  * This is really ugly, but it seams to be the only
32  * realiable way to do it, as the cpld state machine 
33  * is unpredictible. So we have a 25us penalty per
34  * write access.
35  */
36 static void nw_en_write(void)
37 {
38         extern spinlock_t gpio_lock;
39         unsigned long flags;
40
41         /*
42          * we want to write a bit pattern XXX1 to Xilinx to enable
43          * the write gate, which will be open for about the next 2ms.
44          */
45         spin_lock_irqsave(&gpio_lock, flags);
46         cpld_modify(1, 1);
47         spin_unlock_irqrestore(&gpio_lock, flags);
48
49         /*
50          * let the ISA bus to catch on...
51          */
52         udelay(25);
53 }
54 #else
55 #define nw_en_write() do { } while (0)
56 #endif
57
58 static map_word dc21285_read8(struct map_info *map, unsigned long ofs)
59 {
60         map_word val;
61         val.x[0] = *(uint8_t*)(map->virt + ofs);
62         return val;
63 }
64
65 static map_word dc21285_read16(struct map_info *map, unsigned long ofs)
66 {
67         map_word val;
68         val.x[0] = *(uint16_t*)(map->virt + ofs);
69         return val;
70 }
71
72 static map_word dc21285_read32(struct map_info *map, unsigned long ofs)
73 {
74         map_word val;
75         val.x[0] = *(uint32_t*)(map->virt + ofs);
76         return val;
77 }
78
79 static void dc21285_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
80 {
81         memcpy(to, (void*)(map->virt + from), len);
82 }
83
84 static void dc21285_write8(struct map_info *map, const map_word d, unsigned long adr)
85 {
86         if (machine_is_netwinder())
87                 nw_en_write();
88         *CSR_ROMWRITEREG = adr & 3;
89         adr &= ~3;
90         *(uint8_t*)(map->virt + adr) = d.x[0];
91 }
92
93 static void dc21285_write16(struct map_info *map, const map_word d, unsigned long adr)
94 {
95         if (machine_is_netwinder())
96                 nw_en_write();
97         *CSR_ROMWRITEREG = adr & 3;
98         adr &= ~3;
99         *(uint16_t*)(map->virt + adr) = d.x[0];
100 }
101
102 static void dc21285_write32(struct map_info *map, const map_word d, unsigned long adr)
103 {
104         if (machine_is_netwinder())
105                 nw_en_write();
106         *(uint32_t*)(map->virt + adr) = d.x[0];
107 }
108
109 static void dc21285_copy_to_32(struct map_info *map, unsigned long to, const void *from, ssize_t len)
110 {
111         while (len > 0) {
112                 map_word d;
113                 d.x[0] = *((uint32_t*)from)++;
114                 dc21285_write32(map, d, to);
115                 to += 4;
116                 len -= 4;
117         }
118 }
119
120 static void dc21285_copy_to_16(struct map_info *map, unsigned long to, const void *from, ssize_t len)
121 {
122         while (len > 0) {
123                 map_word d;
124                 d.x[0] = *((uint16_t*)from)++;
125                 dc21285_write16(map, d, to);
126                 to += 2;
127                 len -= 2;
128         }
129 }
130
131 static void dc21285_copy_to_8(struct map_info *map, unsigned long to, const void *from, ssize_t len)
132 {
133         map_word d;
134         d.x[0] = *((uint8_t*)from)++;
135         dc21285_write8(map, d, to);
136         to++;
137         len--;
138 }
139
140 static struct map_info dc21285_map = {
141         .name = "DC21285 flash",
142         .phys = NO_XIP,
143         .size = 16*1024*1024,
144         .copy_from = dc21285_copy_from,
145 };
146
147
148 /* Partition stuff */
149 #ifdef CONFIG_MTD_PARTITIONS
150 static struct mtd_partition *dc21285_parts;
151 static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
152 #endif
153   
154 static int __init init_dc21285(void)
155 {
156
157 #ifdef CONFIG_MTD_PARTITIONS
158         int nrparts;
159 #endif
160
161         /* Determine bankwidth */
162         switch (*CSR_SA110_CNTL & (3<<14)) {
163                 case SA110_CNTL_ROMWIDTH_8: 
164                         dc21285_map.bankwidth = 1;
165                         dc21285_map.read = dc21285_read8;
166                         dc21285_map.write = dc21285_write8;
167                         dc21285_map.copy_to = dc21285_copy_to_8;
168                         break;
169                 case SA110_CNTL_ROMWIDTH_16: 
170                         dc21285_map.bankwidth = 2; 
171                         dc21285_map.read = dc21285_read16;
172                         dc21285_map.write = dc21285_write16;
173                         dc21285_map.copy_to = dc21285_copy_to_16;
174                         break;
175                 case SA110_CNTL_ROMWIDTH_32: 
176                         dc21285_map.bankwidth = 4; 
177                         dc21285_map.read = dc21285_read32;
178                         dc21285_map.write = dc21285_write32;
179                         dc21285_map.copy_to = dc21285_copy_to_32;
180                         break;
181                 default:
182                         printk (KERN_ERR "DC21285 flash: undefined bankwidth\n");
183                         return -ENXIO;
184         }
185         printk (KERN_NOTICE "DC21285 flash support (%d-bit bankwidth)\n",
186                 dc21285_map.bankwidth*8);
187
188         /* Let's map the flash area */
189         dc21285_map.virt = ioremap(DC21285_FLASH, 16*1024*1024);
190         if (!dc21285_map.virt) {
191                 printk("Failed to ioremap\n");
192                 return -EIO;
193         }
194
195         if (machine_is_ebsa285()) {
196                 dc21285_mtd = do_map_probe("cfi_probe", &dc21285_map);
197         } else {
198                 dc21285_mtd = do_map_probe("jedec_probe", &dc21285_map);
199         }
200
201         if (!dc21285_mtd) {
202                 iounmap(dc21285_map.virt);
203                 return -ENXIO;
204         }       
205         
206         dc21285_mtd->owner = THIS_MODULE;
207
208 #ifdef CONFIG_MTD_PARTITIONS
209         nrparts = parse_mtd_partitions(dc21285_mtd, probes, &dc21285_parts, 0);
210         if (nrparts > 0)
211                 add_mtd_partitions(dc21285_mtd, dc21285_parts, nrparts);
212         else    
213 #endif  
214                 add_mtd_device(dc21285_mtd);
215                         
216         if(machine_is_ebsa285()) {
217                 /* 
218                  * Flash timing is determined with bits 19-16 of the
219                  * CSR_SA110_CNTL.  The value is the number of wait cycles, or
220                  * 0 for 16 cycles (the default).  Cycles are 20 ns.
221                  * Here we use 7 for 140 ns flash chips.
222                  */
223                 /* access time */
224                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x000f0000) | (7 << 16));
225                 /* burst time */
226                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x00f00000) | (7 << 20));
227                 /* tristate time */
228                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x0f000000) | (7 << 24));
229         }
230         
231         return 0;
232 }
233
234 static void __exit cleanup_dc21285(void)
235 {
236 #ifdef CONFIG_MTD_PARTITIONS
237         if (dc21285_parts) {
238                 del_mtd_partitions(dc21285_mtd);
239                 kfree(dc21285_parts);
240         } else
241 #endif
242                 del_mtd_device(dc21285_mtd);
243
244         map_destroy(dc21285_mtd);
245         iounmap(dc21285_map.virt);
246 }
247
248 module_init(init_dc21285);
249 module_exit(cleanup_dc21285);
250
251
252 MODULE_LICENSE("GPL");
253 MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>");
254 MODULE_DESCRIPTION("MTD map driver for DC21285 boards");