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   $Id: sbc_gxx.c,v 1.1.1.1 2007/08/03 18:52:44 Exp $
21
22The SBC-MediaGX / SBC-GXx has up to 16 MiB of
23Intel StrataFlash (28F320/28F640) in x8 mode.
24
25This driver uses the CFI probe and Intel Extended Command Set drivers.
26
27The flash is accessed as follows:
28
29   16 KiB memory window at 0xdc000-0xdffff
30
31   Two IO address locations for paging
32
33   0x258
34       bit 0-7: address bit 14-21
35   0x259
36       bit 0-1: address bit 22-23
37       bit 7:   0 - reset/powered down
38                1 - device enabled
39
40The single flash device is divided into 3 partition which appear as
41separate MTD devices.
42
4325/04/2001 AJL (Arcom)  Modified signon strings and partition sizes
44                        (to support bzImages up to 638KiB-ish)
45*/
46
47// Includes
48
49#include <linux/module.h>
50#include <linux/slab.h>
51#include <linux/ioport.h>
52#include <linux/init.h>
53#include <asm/io.h>
54
55#include <linux/mtd/mtd.h>
56#include <linux/mtd/map.h>
57#include <linux/mtd/partitions.h>
58
59// Defines
60
61// - Hardware specific
62
63#define WINDOW_START 0xdc000
64
65/* Number of bits in offset. */
66#define WINDOW_SHIFT 14
67#define WINDOW_LENGTH (1 << WINDOW_SHIFT)
68
69/* The bits for the offset into the window. */
70#define WINDOW_MASK (WINDOW_LENGTH-1)
71#define PAGE_IO 0x258
72#define PAGE_IO_SIZE 2
73
74/* bit 7 of 0x259 must be 1 to enable device. */
75#define DEVICE_ENABLE 0x8000
76
77// - Flash / Partition sizing
78
79#define MAX_SIZE_KiB             16384
80#define BOOT_PARTITION_SIZE_KiB  768
81#define DATA_PARTITION_SIZE_KiB  1280
82#define APP_PARTITION_SIZE_KiB   6144
83
84// Globals
85
86static volatile int page_in_window = -1; // Current page in window.
87static void __iomem *iomapadr;
88static DEFINE_SPINLOCK(sbc_gxx_spin);
89
90/* partition_info gives details on the logical partitions that the split the
91 * single flash device into. If the size if zero we use up to the end of the
92 * device. */
93static struct mtd_partition partition_info[]={
94    { .name = "SBC-GXx flash boot partition",
95      .offset = 0,
96      .size =   BOOT_PARTITION_SIZE_KiB*1024 },
97    { .name = "SBC-GXx flash data partition",
98      .offset = BOOT_PARTITION_SIZE_KiB*1024,
99      .size = (DATA_PARTITION_SIZE_KiB)*1024 },
100    { .name = "SBC-GXx flash application partition",
101      .offset = (BOOT_PARTITION_SIZE_KiB+DATA_PARTITION_SIZE_KiB)*1024 }
102};
103
104#define NUM_PARTITIONS 3
105
106static inline void sbc_gxx_page(struct map_info *map, unsigned long ofs)
107{
108	unsigned long page = ofs >> WINDOW_SHIFT;
109
110	if( page!=page_in_window ) {
111		outw( page | DEVICE_ENABLE, PAGE_IO );
112		page_in_window = page;
113	}
114}
115
116
117static map_word sbc_gxx_read8(struct map_info *map, unsigned long ofs)
118{
119	map_word ret;
120	spin_lock(&sbc_gxx_spin);
121	sbc_gxx_page(map, ofs);
122	ret.x[0] = readb(iomapadr + (ofs & WINDOW_MASK));
123	spin_unlock(&sbc_gxx_spin);
124	return ret;
125}
126
127static void sbc_gxx_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
128{
129	while(len) {
130		unsigned long thislen = len;
131		if (len > (WINDOW_LENGTH - (from & WINDOW_MASK)))
132			thislen = WINDOW_LENGTH-(from & WINDOW_MASK);
133
134		spin_lock(&sbc_gxx_spin);
135		sbc_gxx_page(map, from);
136		memcpy_fromio(to, iomapadr + (from & WINDOW_MASK), thislen);
137		spin_unlock(&sbc_gxx_spin);
138		to += thislen;
139		from += thislen;
140		len -= thislen;
141	}
142}
143
144static void sbc_gxx_write8(struct map_info *map, map_word d, unsigned long adr)
145{
146	spin_lock(&sbc_gxx_spin);
147	sbc_gxx_page(map, adr);
148	writeb(d.x[0], iomapadr + (adr & WINDOW_MASK));
149	spin_unlock(&sbc_gxx_spin);
150}
151
152static void sbc_gxx_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
153{
154	while(len) {
155		unsigned long thislen = len;
156		if (len > (WINDOW_LENGTH - (to & WINDOW_MASK)))
157			thislen = WINDOW_LENGTH-(to & WINDOW_MASK);
158
159		spin_lock(&sbc_gxx_spin);
160		sbc_gxx_page(map, to);
161		memcpy_toio(iomapadr + (to & WINDOW_MASK), from, thislen);
162		spin_unlock(&sbc_gxx_spin);
163		to += thislen;
164		from += thislen;
165		len -= thislen;
166	}
167}
168
169static struct map_info sbc_gxx_map = {
170	.name = "SBC-GXx flash",
171	.phys = NO_XIP,
172	.size = MAX_SIZE_KiB*1024, /* this must be set to a maximum possible amount
173			 of flash so the cfi probe routines find all
174			 the chips */
175	.bankwidth = 1,
176	.read = sbc_gxx_read8,
177	.copy_from = sbc_gxx_copy_from,
178	.write = sbc_gxx_write8,
179	.copy_to = sbc_gxx_copy_to
180};
181
182/* MTD device for all of the flash. */
183static struct mtd_info *all_mtd;
184
185static void cleanup_sbc_gxx(void)
186{
187	if( all_mtd ) {
188		del_mtd_partitions( all_mtd );
189		map_destroy( all_mtd );
190	}
191
192	iounmap(iomapadr);
193	release_region(PAGE_IO,PAGE_IO_SIZE);
194}
195
196static int __init init_sbc_gxx(void)
197{
198  	iomapadr = ioremap(WINDOW_START, WINDOW_LENGTH);
199	if (!iomapadr) {
200		printk( KERN_ERR"%s: failed to ioremap memory region\n",
201			sbc_gxx_map.name );
202		return -EIO;
203	}
204
205	if (!request_region( PAGE_IO, PAGE_IO_SIZE, "SBC-GXx flash")) {
206		printk( KERN_ERR"%s: IO ports 0x%x-0x%x in use\n",
207			sbc_gxx_map.name,
208			PAGE_IO, PAGE_IO+PAGE_IO_SIZE-1 );
209		iounmap(iomapadr);
210		return -EAGAIN;
211	}
212
213
214	printk( KERN_INFO"%s: IO:0x%x-0x%x MEM:0x%x-0x%x\n",
215		sbc_gxx_map.name,
216		PAGE_IO, PAGE_IO+PAGE_IO_SIZE-1,
217		WINDOW_START, WINDOW_START+WINDOW_LENGTH-1 );
218
219	/* Probe for chip. */
220	all_mtd = do_map_probe( "cfi_probe", &sbc_gxx_map );
221	if( !all_mtd ) {
222		cleanup_sbc_gxx();
223		return -ENXIO;
224	}
225
226	all_mtd->owner = THIS_MODULE;
227
228	/* Create MTD devices for each partition. */
229	add_mtd_partitions(all_mtd, partition_info, NUM_PARTITIONS );
230
231	return 0;
232}
233
234module_init(init_sbc_gxx);
235module_exit(cleanup_sbc_gxx);
236
237MODULE_LICENSE("GPL");
238MODULE_AUTHOR("Arcom Control Systems Ltd.");
239MODULE_DESCRIPTION("MTD map driver for SBC-GXm and SBC-GX1 series boards");
240