1 /* sbc_gxx.c -- MTD map driver for Arcom Control Systems SBC-MediaGX,
2                 SBC-GXm and SBC-GX1 series boards.
3 
4    Copyright (C) 2001 Arcom Control System Ltd
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 The SBC-MediaGX / SBC-GXx has up to 16 MiB of
21 Intel StrataFlash (28F320/28F640) in x8 mode.
22 
23 This driver uses the CFI probe and Intel Extended Command Set drivers.
24 
25 The flash is accessed as follows:
26 
27    16 KiB memory window at 0xdc000-0xdffff
28 
29    Two IO address locations for paging
30 
31    0x258
32        bit 0-7: address bit 14-21
33    0x259
34        bit 0-1: address bit 22-23
35        bit 7:   0 - reset/powered down
36                 1 - device enabled
37 
38 The single flash device is divided into 3 partition which appear as
39 separate MTD devices.
40 
41 25/04/2001 AJL (Arcom)  Modified signon strings and partition sizes
42                         (to support bzImages up to 638KiB-ish)
43 */
44 
45 // Includes
46 
47 #include <linux/module.h>
48 #include <linux/ioport.h>
49 #include <linux/init.h>
50 #include <asm/io.h>
51 
52 #include <linux/mtd/mtd.h>
53 #include <linux/mtd/map.h>
54 #include <linux/mtd/partitions.h>
55 
56 // Defines
57 
58 // - Hardware specific
59 
60 #define WINDOW_START 0xdc000
61 
62 /* Number of bits in offset. */
63 #define WINDOW_SHIFT 14
64 #define WINDOW_LENGTH (1 << WINDOW_SHIFT)
65 
66 /* The bits for the offset into the window. */
67 #define WINDOW_MASK (WINDOW_LENGTH-1)
68 #define PAGE_IO 0x258
69 #define PAGE_IO_SIZE 2
70 
71 /* bit 7 of 0x259 must be 1 to enable device. */
72 #define DEVICE_ENABLE 0x8000
73 
74 // - Flash / Partition sizing
75 
76 #define MAX_SIZE_KiB             16384
77 #define BOOT_PARTITION_SIZE_KiB  768
78 #define DATA_PARTITION_SIZE_KiB  1280
79 #define APP_PARTITION_SIZE_KiB   6144
80 
81 // Globals
82 
83 static volatile int page_in_window = -1; // Current page in window.
84 static void __iomem *iomapadr;
85 static DEFINE_SPINLOCK(sbc_gxx_spin);
86 
87 /* partition_info gives details on the logical partitions that the split the
88  * single flash device into. If the size if zero we use up to the end of the
89  * device. */
90 static struct mtd_partition partition_info[]={
91     { .name = "SBC-GXx flash boot partition",
92       .offset = 0,
93       .size =   BOOT_PARTITION_SIZE_KiB*1024 },
94     { .name = "SBC-GXx flash data partition",
95       .offset = BOOT_PARTITION_SIZE_KiB*1024,
96       .size = (DATA_PARTITION_SIZE_KiB)*1024 },
97     { .name = "SBC-GXx flash application partition",
98       .offset = (BOOT_PARTITION_SIZE_KiB+DATA_PARTITION_SIZE_KiB)*1024 }
99 };
100 
101 #define NUM_PARTITIONS 3
102 
sbc_gxx_page(struct map_info * map,unsigned long ofs)103 static inline void sbc_gxx_page(struct map_info *map, unsigned long ofs)
104 {
105 	unsigned long page = ofs >> WINDOW_SHIFT;
106 
107 	if( page!=page_in_window ) {
108 		outw( page | DEVICE_ENABLE, PAGE_IO );
109 		page_in_window = page;
110 	}
111 }
112 
113 
sbc_gxx_read8(struct map_info * map,unsigned long ofs)114 static map_word sbc_gxx_read8(struct map_info *map, unsigned long ofs)
115 {
116 	map_word ret;
117 	spin_lock(&sbc_gxx_spin);
118 	sbc_gxx_page(map, ofs);
119 	ret.x[0] = readb(iomapadr + (ofs & WINDOW_MASK));
120 	spin_unlock(&sbc_gxx_spin);
121 	return ret;
122 }
123 
sbc_gxx_copy_from(struct map_info * map,void * to,unsigned long from,ssize_t len)124 static void sbc_gxx_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
125 {
126 	while(len) {
127 		unsigned long thislen = len;
128 		if (len > (WINDOW_LENGTH - (from & WINDOW_MASK)))
129 			thislen = WINDOW_LENGTH-(from & WINDOW_MASK);
130 
131 		spin_lock(&sbc_gxx_spin);
132 		sbc_gxx_page(map, from);
133 		memcpy_fromio(to, iomapadr + (from & WINDOW_MASK), thislen);
134 		spin_unlock(&sbc_gxx_spin);
135 		to += thislen;
136 		from += thislen;
137 		len -= thislen;
138 	}
139 }
140 
sbc_gxx_write8(struct map_info * map,map_word d,unsigned long adr)141 static void sbc_gxx_write8(struct map_info *map, map_word d, unsigned long adr)
142 {
143 	spin_lock(&sbc_gxx_spin);
144 	sbc_gxx_page(map, adr);
145 	writeb(d.x[0], iomapadr + (adr & WINDOW_MASK));
146 	spin_unlock(&sbc_gxx_spin);
147 }
148 
sbc_gxx_copy_to(struct map_info * map,unsigned long to,const void * from,ssize_t len)149 static void sbc_gxx_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
150 {
151 	while(len) {
152 		unsigned long thislen = len;
153 		if (len > (WINDOW_LENGTH - (to & WINDOW_MASK)))
154 			thislen = WINDOW_LENGTH-(to & WINDOW_MASK);
155 
156 		spin_lock(&sbc_gxx_spin);
157 		sbc_gxx_page(map, to);
158 		memcpy_toio(iomapadr + (to & WINDOW_MASK), from, thislen);
159 		spin_unlock(&sbc_gxx_spin);
160 		to += thislen;
161 		from += thislen;
162 		len -= thislen;
163 	}
164 }
165 
166 static struct map_info sbc_gxx_map = {
167 	.name = "SBC-GXx flash",
168 	.phys = NO_XIP,
169 	.size = MAX_SIZE_KiB*1024, /* this must be set to a maximum possible amount
170 			 of flash so the cfi probe routines find all
171 			 the chips */
172 	.bankwidth = 1,
173 	.read = sbc_gxx_read8,
174 	.copy_from = sbc_gxx_copy_from,
175 	.write = sbc_gxx_write8,
176 	.copy_to = sbc_gxx_copy_to
177 };
178 
179 /* MTD device for all of the flash. */
180 static struct mtd_info *all_mtd;
181 
cleanup_sbc_gxx(void)182 static void cleanup_sbc_gxx(void)
183 {
184 	if( all_mtd ) {
185 		mtd_device_unregister(all_mtd);
186 		map_destroy( all_mtd );
187 	}
188 
189 	iounmap(iomapadr);
190 	release_region(PAGE_IO,PAGE_IO_SIZE);
191 }
192 
init_sbc_gxx(void)193 static int __init init_sbc_gxx(void)
194 {
195   	iomapadr = ioremap(WINDOW_START, WINDOW_LENGTH);
196 	if (!iomapadr) {
197 		printk( KERN_ERR"%s: failed to ioremap memory region\n",
198 			sbc_gxx_map.name );
199 		return -EIO;
200 	}
201 
202 	if (!request_region( PAGE_IO, PAGE_IO_SIZE, "SBC-GXx flash")) {
203 		printk( KERN_ERR"%s: IO ports 0x%x-0x%x in use\n",
204 			sbc_gxx_map.name,
205 			PAGE_IO, PAGE_IO+PAGE_IO_SIZE-1 );
206 		iounmap(iomapadr);
207 		return -EAGAIN;
208 	}
209 
210 
211 	printk( KERN_INFO"%s: IO:0x%x-0x%x MEM:0x%x-0x%x\n",
212 		sbc_gxx_map.name,
213 		PAGE_IO, PAGE_IO+PAGE_IO_SIZE-1,
214 		WINDOW_START, WINDOW_START+WINDOW_LENGTH-1 );
215 
216 	/* Probe for chip. */
217 	all_mtd = do_map_probe( "cfi_probe", &sbc_gxx_map );
218 	if( !all_mtd ) {
219 		cleanup_sbc_gxx();
220 		return -ENXIO;
221 	}
222 
223 	all_mtd->owner = THIS_MODULE;
224 
225 	/* Create MTD devices for each partition. */
226 	mtd_device_register(all_mtd, partition_info, NUM_PARTITIONS);
227 
228 	return 0;
229 }
230 
231 module_init(init_sbc_gxx);
232 module_exit(cleanup_sbc_gxx);
233 
234 MODULE_LICENSE("GPL");
235 MODULE_AUTHOR("Arcom Control Systems Ltd.");
236 MODULE_DESCRIPTION("MTD map driver for SBC-GXm and SBC-GX1 series boards");
237