xref: /openbmc/linux/drivers/mtd/maps/sbc_gxx.c (revision 842ed298)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* sbc_gxx.c -- MTD map driver for Arcom Control Systems SBC-MediaGX,
3                 SBC-GXm and SBC-GX1 series boards.
4 
5    Copyright (C) 2001 Arcom Control System Ltd
6 
7 
8 The SBC-MediaGX / SBC-GXx has up to 16 MiB of
9 Intel StrataFlash (28F320/28F640) in x8 mode.
10 
11 This driver uses the CFI probe and Intel Extended Command Set drivers.
12 
13 The flash is accessed as follows:
14 
15    16 KiB memory window at 0xdc000-0xdffff
16 
17    Two IO address locations for paging
18 
19    0x258
20        bit 0-7: address bit 14-21
21    0x259
22        bit 0-1: address bit 22-23
23        bit 7:   0 - reset/powered down
24                 1 - device enabled
25 
26 The single flash device is divided into 3 partition which appear as
27 separate MTD devices.
28 
29 25/04/2001 AJL (Arcom)  Modified signon strings and partition sizes
30                         (to support bzImages up to 638KiB-ish)
31 */
32 
33 // Includes
34 
35 #include <linux/module.h>
36 #include <linux/ioport.h>
37 #include <linux/init.h>
38 #include <asm/io.h>
39 
40 #include <linux/mtd/mtd.h>
41 #include <linux/mtd/map.h>
42 #include <linux/mtd/partitions.h>
43 
44 // Defines
45 
46 // - Hardware specific
47 
48 #define WINDOW_START 0xdc000
49 
50 /* Number of bits in offset. */
51 #define WINDOW_SHIFT 14
52 #define WINDOW_LENGTH (1 << WINDOW_SHIFT)
53 
54 /* The bits for the offset into the window. */
55 #define WINDOW_MASK (WINDOW_LENGTH-1)
56 #define PAGE_IO 0x258
57 #define PAGE_IO_SIZE 2
58 
59 /* bit 7 of 0x259 must be 1 to enable device. */
60 #define DEVICE_ENABLE 0x8000
61 
62 // - Flash / Partition sizing
63 
64 #define MAX_SIZE_KiB             16384
65 #define BOOT_PARTITION_SIZE_KiB  768
66 #define DATA_PARTITION_SIZE_KiB  1280
67 #define APP_PARTITION_SIZE_KiB   6144
68 
69 // Globals
70 
71 static volatile int page_in_window = -1; // Current page in window.
72 static void __iomem *iomapadr;
73 static DEFINE_SPINLOCK(sbc_gxx_spin);
74 
75 /* partition_info gives details on the logical partitions that the split the
76  * single flash device into. If the size if zero we use up to the end of the
77  * device. */
78 static const struct mtd_partition partition_info[] = {
79     { .name = "SBC-GXx flash boot partition",
80       .offset = 0,
81       .size =   BOOT_PARTITION_SIZE_KiB*1024 },
82     { .name = "SBC-GXx flash data partition",
83       .offset = BOOT_PARTITION_SIZE_KiB*1024,
84       .size = (DATA_PARTITION_SIZE_KiB)*1024 },
85     { .name = "SBC-GXx flash application partition",
86       .offset = (BOOT_PARTITION_SIZE_KiB+DATA_PARTITION_SIZE_KiB)*1024 }
87 };
88 
89 #define NUM_PARTITIONS 3
90 
91 static inline void sbc_gxx_page(struct map_info *map, unsigned long ofs)
92 {
93 	unsigned long page = ofs >> WINDOW_SHIFT;
94 
95 	if( page!=page_in_window ) {
96 		outw( page | DEVICE_ENABLE, PAGE_IO );
97 		page_in_window = page;
98 	}
99 }
100 
101 
102 static map_word sbc_gxx_read8(struct map_info *map, unsigned long ofs)
103 {
104 	map_word ret;
105 	spin_lock(&sbc_gxx_spin);
106 	sbc_gxx_page(map, ofs);
107 	ret.x[0] = readb(iomapadr + (ofs & WINDOW_MASK));
108 	spin_unlock(&sbc_gxx_spin);
109 	return ret;
110 }
111 
112 static void sbc_gxx_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
113 {
114 	while(len) {
115 		unsigned long thislen = len;
116 		if (len > (WINDOW_LENGTH - (from & WINDOW_MASK)))
117 			thislen = WINDOW_LENGTH-(from & WINDOW_MASK);
118 
119 		spin_lock(&sbc_gxx_spin);
120 		sbc_gxx_page(map, from);
121 		memcpy_fromio(to, iomapadr + (from & WINDOW_MASK), thislen);
122 		spin_unlock(&sbc_gxx_spin);
123 		to += thislen;
124 		from += thislen;
125 		len -= thislen;
126 	}
127 }
128 
129 static void sbc_gxx_write8(struct map_info *map, map_word d, unsigned long adr)
130 {
131 	spin_lock(&sbc_gxx_spin);
132 	sbc_gxx_page(map, adr);
133 	writeb(d.x[0], iomapadr + (adr & WINDOW_MASK));
134 	spin_unlock(&sbc_gxx_spin);
135 }
136 
137 static void sbc_gxx_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
138 {
139 	while(len) {
140 		unsigned long thislen = len;
141 		if (len > (WINDOW_LENGTH - (to & WINDOW_MASK)))
142 			thislen = WINDOW_LENGTH-(to & WINDOW_MASK);
143 
144 		spin_lock(&sbc_gxx_spin);
145 		sbc_gxx_page(map, to);
146 		memcpy_toio(iomapadr + (to & WINDOW_MASK), from, thislen);
147 		spin_unlock(&sbc_gxx_spin);
148 		to += thislen;
149 		from += thislen;
150 		len -= thislen;
151 	}
152 }
153 
154 static struct map_info sbc_gxx_map = {
155 	.name = "SBC-GXx flash",
156 	.phys = NO_XIP,
157 	.size = MAX_SIZE_KiB*1024, /* this must be set to a maximum possible amount
158 			 of flash so the cfi probe routines find all
159 			 the chips */
160 	.bankwidth = 1,
161 	.read = sbc_gxx_read8,
162 	.copy_from = sbc_gxx_copy_from,
163 	.write = sbc_gxx_write8,
164 	.copy_to = sbc_gxx_copy_to
165 };
166 
167 /* MTD device for all of the flash. */
168 static struct mtd_info *all_mtd;
169 
170 static void cleanup_sbc_gxx(void)
171 {
172 	if( all_mtd ) {
173 		mtd_device_unregister(all_mtd);
174 		map_destroy( all_mtd );
175 	}
176 
177 	iounmap(iomapadr);
178 	release_region(PAGE_IO,PAGE_IO_SIZE);
179 }
180 
181 static int __init init_sbc_gxx(void)
182 {
183   	iomapadr = ioremap(WINDOW_START, WINDOW_LENGTH);
184 	if (!iomapadr) {
185 		printk( KERN_ERR"%s: failed to ioremap memory region\n",
186 			sbc_gxx_map.name );
187 		return -EIO;
188 	}
189 
190 	if (!request_region( PAGE_IO, PAGE_IO_SIZE, "SBC-GXx flash")) {
191 		printk( KERN_ERR"%s: IO ports 0x%x-0x%x in use\n",
192 			sbc_gxx_map.name,
193 			PAGE_IO, PAGE_IO+PAGE_IO_SIZE-1 );
194 		iounmap(iomapadr);
195 		return -EAGAIN;
196 	}
197 
198 
199 	printk( KERN_INFO"%s: IO:0x%x-0x%x MEM:0x%x-0x%x\n",
200 		sbc_gxx_map.name,
201 		PAGE_IO, PAGE_IO+PAGE_IO_SIZE-1,
202 		WINDOW_START, WINDOW_START+WINDOW_LENGTH-1 );
203 
204 	/* Probe for chip. */
205 	all_mtd = do_map_probe( "cfi_probe", &sbc_gxx_map );
206 	if( !all_mtd ) {
207 		cleanup_sbc_gxx();
208 		return -ENXIO;
209 	}
210 
211 	all_mtd->owner = THIS_MODULE;
212 
213 	/* Create MTD devices for each partition. */
214 	mtd_device_register(all_mtd, partition_info, NUM_PARTITIONS);
215 
216 	return 0;
217 }
218 
219 module_init(init_sbc_gxx);
220 module_exit(cleanup_sbc_gxx);
221 
222 MODULE_LICENSE("GPL");
223 MODULE_AUTHOR("Arcom Control Systems Ltd.");
224 MODULE_DESCRIPTION("MTD map driver for SBC-GXm and SBC-GX1 series boards");
225