1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
From b6d5d4c3d595b4cfb6a052ac7151fdb1d9a776ea Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Sun, 27 Jul 2014 09:58:09 +0100
Subject: [PATCH 44/57] mtd: add chunked read io to m25p80
Signed-off-by: John Crispin <blogic@openwrt.org>
---
drivers/mtd/devices/m25p80.c | 128 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 128 insertions(+)
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -562,6 +562,58 @@ static int m25p80_read(struct mtd_info *
return 0;
}
+static int m25p80_read_chunked(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, u_char *buf)
+{
+ struct m25p *flash = mtd_to_m25p(mtd);
+ struct spi_transfer t[2];
+ struct spi_message m;
+ uint8_t opcode;
+ int idx = 0;
+
+ pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
+ __func__, (u32)from, len);
+
+ spi_message_init(&m);
+ memset(t, 0, (sizeof t));
+
+ t[0].tx_buf = flash->command;
+ t[0].len = m25p_cmdsz(flash);
+ spi_message_add_tail(&t[0], &m);
+ spi_message_add_tail(&t[1], &m);
+
+ *retlen = 0;
+
+ while (idx < len) {
+ int rlen = (len - idx > 4) ? (4) : (len - idx);
+
+ t[1].rx_buf = &buf[idx];
+ t[1].len = rlen;
+
+ mutex_lock(&flash->lock);
+
+ /* Wait till previous write/erase is done. */
+ if (wait_till_ready(flash)) {
+ /* REVISIT status return?? */
+ mutex_unlock(&flash->lock);
+ return 1;
+ }
+
+ /* Set up the write data buffer. */
+ opcode = OPCODE_NORM_READ;
+ flash->command[0] = opcode;
+ m25p_addr2cmd(flash, from + idx, flash->command);
+
+ spi_sync(flash->spi, &m);
+
+ *retlen += m.actual_length - m25p_cmdsz(flash);
+
+ mutex_unlock(&flash->lock);
+ idx += rlen;
+ }
+ return 0;
+}
+
/*
* Write an address range to the flash chip. Data must be written in
* FLASH_PAGESIZE chunks. The address range may be any size provided
@@ -649,6 +701,76 @@ static int m25p80_write(struct mtd_info
return 0;
}
+static int m25p80_write_chunked(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, const u_char *buf)
+{
+ struct m25p *flash = mtd_to_m25p(mtd);
+ struct spi_transfer t;
+ struct spi_message m;
+ u32 i, page_size;
+ u8 tmp[8];
+
+ pr_debug("%s: %s to 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
+ __func__, (u32)to, len);
+
+ spi_message_init(&m);
+ memset(&t, 0, (sizeof t));
+
+ t.tx_buf = tmp;
+ t.len = 8;
+ spi_message_add_tail(&t, &m);
+
+ mutex_lock(&flash->lock);
+
+ /* Wait until finished previous write command. */
+ if (wait_till_ready(flash)) {
+ mutex_unlock(&flash->lock);
+ return 1;
+ }
+
+ write_enable(flash);
+
+ /* Set up the opcode in the write buffer. */
+ flash->command[0] = OPCODE_PP;
+ m25p_addr2cmd(flash, to, flash->command);
+
+ t.len = 4 + (to & 0x3);
+ if (t.len == 4)
+ t.len = 8;
+ memcpy(tmp, flash->command, 4);
+ memcpy(&tmp[4], buf, t.len - 4);
+ spi_sync(flash->spi, &m);
+ page_size = t.len - 4;
+
+ *retlen = m.actual_length - m25p_cmdsz(flash);
+
+ /* write everything in flash->page_size chunks */
+ for (i = page_size; i < len; i += page_size) {
+ page_size = len - i;
+ if (page_size > 4)
+ page_size = 4;
+
+ /* write the next page to flash */
+ m25p_addr2cmd(flash, to + i, flash->command);
+
+ memcpy(tmp, flash->command, 4);
+ memcpy(&tmp[4], buf + i, page_size);
+ t.len = 4 + page_size;
+
+ wait_till_ready(flash);
+
+ write_enable(flash);
+
+ spi_sync(flash->spi, &m);
+
+ *retlen += m.actual_length - m25p_cmdsz(flash);
+ }
+
+ mutex_unlock(&flash->lock);
+
+ return 0;
+}
+
static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
@@ -1260,6 +1382,12 @@ static int m25p_probe(struct spi_device
return -EINVAL;
}
+ if (np && of_property_read_bool(np, "m25p,chunked-io")) {
+ dev_warn(&spi->dev, "using chunked io\n");
+ flash->mtd._read = m25p80_read_chunked;
+ flash->mtd._write = m25p80_write_chunked;
+ }
+
flash->program_opcode = OPCODE_PP;
if (info->addr_width)
|
