1 /*
2  *  Cobalt NOR flash functions
3  *
4  *  Copyright 2012-2015 Cisco Systems, Inc. and/or its affiliates.
5  *  All rights reserved.
6  *
7  *  This program is free software; you may redistribute it and/or modify
8  *  it under the terms of the GNU General Public License as published by
9  *  the Free Software Foundation; version 2 of the License.
10  *
11  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
12  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
13  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
14  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
15  *  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
16  *  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
17  *  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
18  *  SOFTWARE.
19  */
20 
21 #include <linux/mtd/mtd.h>
22 #include <linux/mtd/map.h>
23 #include <linux/mtd/cfi.h>
24 #include <linux/time.h>
25 
26 #include "cobalt-flash.h"
27 
28 #define ADRS(offset) (COBALT_BUS_FLASH_BASE + offset)
29 
30 static struct map_info cobalt_flash_map = {
31 	.name =		"cobalt-flash",
32 	.bankwidth =	2,         /* 16 bits */
33 	.size =		0x4000000, /* 64MB */
34 	.phys =		0,         /* offset  */
35 };
36 
37 static map_word flash_read16(struct map_info *map, unsigned long offset)
38 {
39 	map_word r;
40 
41 	r.x[0] = cobalt_bus_read32(map->virt, ADRS(offset));
42 	if (offset & 0x2)
43 		r.x[0] >>= 16;
44 	else
45 		r.x[0] &= 0x0000ffff;
46 
47 	return r;
48 }
49 
50 static void flash_write16(struct map_info *map, const map_word datum,
51 			  unsigned long offset)
52 {
53 	u16 data = (u16)datum.x[0];
54 
55 	cobalt_bus_write16(map->virt, ADRS(offset), data);
56 }
57 
58 static void flash_copy_from(struct map_info *map, void *to,
59 			    unsigned long from, ssize_t len)
60 {
61 	u32 src = from;
62 	u8 *dest = to;
63 	u32 data;
64 
65 	while (len) {
66 		data = cobalt_bus_read32(map->virt, ADRS(src));
67 		do {
68 			*dest = data >> (8 * (src & 3));
69 			src++;
70 			dest++;
71 			len--;
72 		} while (len && (src % 4));
73 	}
74 }
75 
76 static void flash_copy_to(struct map_info *map, unsigned long to,
77 			  const void *from, ssize_t len)
78 {
79 	const u8 *src = from;
80 	u32 dest = to;
81 
82 	pr_info("%s: offset 0x%x: length %zu\n", __func__, dest, len);
83 	while (len) {
84 		u16 data = 0xffff;
85 
86 		do {
87 			data = *src << (8 * (dest & 1));
88 			src++;
89 			dest++;
90 			len--;
91 		} while (len && (dest % 2));
92 
93 		cobalt_bus_write16(map->virt, ADRS(dest - 2), data);
94 	}
95 }
96 
97 int cobalt_flash_probe(struct cobalt *cobalt)
98 {
99 	struct map_info *map = &cobalt_flash_map;
100 	struct mtd_info *mtd;
101 
102 	BUG_ON(!map_bankwidth_supported(map->bankwidth));
103 	map->virt = cobalt->bar1;
104 	map->read = flash_read16;
105 	map->write = flash_write16;
106 	map->copy_from = flash_copy_from;
107 	map->copy_to = flash_copy_to;
108 
109 	mtd = do_map_probe("cfi_probe", map);
110 	cobalt->mtd = mtd;
111 	if (!mtd) {
112 		cobalt_err("Probe CFI flash failed!\n");
113 		return -1;
114 	}
115 
116 	mtd->owner = THIS_MODULE;
117 	mtd->dev.parent = &cobalt->pci_dev->dev;
118 	mtd_device_register(mtd, NULL, 0);
119 	return 0;
120 }
121 
122 void cobalt_flash_remove(struct cobalt *cobalt)
123 {
124 	if (cobalt->mtd) {
125 		mtd_device_unregister(cobalt->mtd);
126 		map_destroy(cobalt->mtd);
127 	}
128 }
129