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
18static 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
25static 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
38static 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
46static 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
64static 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;
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
85int 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
110void 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