1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Cobalt NOR flash functions
4  *
5  *  Copyright 2012-2015 Cisco Systems, Inc. and/or its affiliates.
6  *  All rights reserved.
7  */
8 
9 #include <linux/mtd/mtd.h>
10 #include <linux/mtd/map.h>
11 #include <linux/mtd/cfi.h>
12 #include <linux/time.h>
13 
14 #include "cobalt-flash.h"
15 
16 #define ADRS(offset) (COBALT_BUS_FLASH_BASE + offset)
17 
18 static struct map_info cobalt_flash_map = {
19 	.name =		"cobalt-flash",
20 	.bankwidth =	2,         /* 16 bits */
21 	.size =		0x4000000, /* 64MB */
22 	.phys =		0,         /* offset  */
23 };
24 
25 static map_word flash_read16(struct map_info *map, unsigned long offset)
26 {
27 	map_word r;
28 
29 	r.x[0] = cobalt_bus_read32(map->virt, ADRS(offset));
30 	if (offset & 0x2)
31 		r.x[0] >>= 16;
32 	else
33 		r.x[0] &= 0x0000ffff;
34 
35 	return r;
36 }
37 
38 static void flash_write16(struct map_info *map, const map_word datum,
39 			  unsigned long offset)
40 {
41 	u16 data = (u16)datum.x[0];
42 
43 	cobalt_bus_write16(map->virt, ADRS(offset), data);
44 }
45 
46 static void flash_copy_from(struct map_info *map, void *to,
47 			    unsigned long from, ssize_t len)
48 {
49 	u32 src = from;
50 	u8 *dest = to;
51 	u32 data;
52 
53 	while (len) {
54 		data = cobalt_bus_read32(map->virt, ADRS(src));
55 		do {
56 			*dest = data >> (8 * (src & 3));
57 			src++;
58 			dest++;
59 			len--;
60 		} while (len && (src % 4));
61 	}
62 }
63 
64 static void flash_copy_to(struct map_info *map, unsigned long to,
65 			  const void *from, ssize_t len)
66 {
67 	const u8 *src = from;
68 	u32 dest = to;
69 
70 	pr_info("%s: offset 0x%x: length %zu\n", __func__, dest, len);
71 	while (len) {
72 		u16 data = 0xffff;
73 
74 		do {
75 			data = *src << (8 * (dest & 1));
76 			src++;
77 			dest++;
78 			len--;
79 		} while (len && (dest % 2));
80 
81 		cobalt_bus_write16(map->virt, ADRS(dest - 2), data);
82 	}
83 }
84 
85 int cobalt_flash_probe(struct cobalt *cobalt)
86 {
87 	struct map_info *map = &cobalt_flash_map;
88 	struct mtd_info *mtd;
89 
90 	BUG_ON(!map_bankwidth_supported(map->bankwidth));
91 	map->virt = cobalt->bar1;
92 	map->read = flash_read16;
93 	map->write = flash_write16;
94 	map->copy_from = flash_copy_from;
95 	map->copy_to = flash_copy_to;
96 
97 	mtd = do_map_probe("cfi_probe", map);
98 	cobalt->mtd = mtd;
99 	if (!mtd) {
100 		cobalt_err("Probe CFI flash failed!\n");
101 		return -1;
102 	}
103 
104 	mtd->owner = THIS_MODULE;
105 	mtd->dev.parent = &cobalt->pci_dev->dev;
106 	mtd_device_register(mtd, NULL, 0);
107 	return 0;
108 }
109 
110 void cobalt_flash_remove(struct cobalt *cobalt)
111 {
112 	if (cobalt->mtd) {
113 		mtd_device_unregister(cobalt->mtd);
114 		map_destroy(cobalt->mtd);
115 	}
116 }
117