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
8The SBC-MediaGX / SBC-GXx has up to 16 MiB of
9Intel StrataFlash (28F320/28F640) in x8 mode.
10
11This driver uses the CFI probe and Intel Extended Command Set drivers.
12
13The 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
26The single flash device is divided into 3 partition which appear as
27separate MTD devices.
28
2925/04/2001 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
71static volatile int page_in_window = -1; // Current page in window.
72static void __iomem *iomapadr;
73static 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. */
78static 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
91static 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
102static 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
112static 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
129static 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
137static 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
154static 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. */
168static struct mtd_info *all_mtd;
169
170static 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
181static 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
219module_init(init_sbc_gxx);
220module_exit(cleanup_sbc_gxx);
221
222MODULE_LICENSE("GPL");
223MODULE_AUTHOR("Arcom Control Systems Ltd.");
224MODULE_DESCRIPTION("MTD map driver for SBC-GXm and SBC-GX1 series boards");
225