aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/tx4938/toshiba_rbtx4938/spi_eeprom.c
blob: 89596e62f9096cf5f9313c6d87e121bc58afaa5c (plain)
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
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
/*
 * linux/arch/mips/tx4938/toshiba_rbtx4938/spi_eeprom.c
 * Copyright (C) 2000-2001 Toshiba Corporation
 *
 * 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
 * terms of the GNU General Public License version 2. This program is
 * licensed "as is" without any warranty of any kind, whether express
 * or implied.
 *
 * Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
 */
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <asm/tx4938/spi.h>
#include <asm/tx4938/tx4938.h>

/* ATMEL 250x0 instructions */
#define	ATMEL_WREN	0x06
#define	ATMEL_WRDI	0x04
#define ATMEL_RDSR	0x05
#define ATMEL_WRSR	0x01
#define	ATMEL_READ	0x03
#define	ATMEL_WRITE	0x02

#define ATMEL_SR_BSY	0x01
#define ATMEL_SR_WEN	0x02
#define ATMEL_SR_BP0	0x04
#define ATMEL_SR_BP1	0x08

DEFINE_SPINLOCK(spi_eeprom_lock);

static struct spi_dev_desc seeprom_dev_desc = {
	.baud 		= 1500000,	/* 1.5Mbps */
	.tcss		= 1,
	.tcsh		= 1,
	.tcsr		= 1,
	.byteorder	= 1,		/* MSB-First */
	.polarity	= 0,		/* High-Active */
	.phase		= 0,		/* Sample-Then-Shift */

};
static inline int
spi_eeprom_io(int chipid,
	      unsigned char **inbufs, unsigned int *incounts,
	      unsigned char **outbufs, unsigned int *outcounts)
{
	return txx9_spi_io(chipid, &seeprom_dev_desc,
			   inbufs, incounts, outbufs, outcounts, 0);
}

int spi_eeprom_write_enable(int chipid, int enable)
{
	unsigned char inbuf[1];
	unsigned char *inbufs[1];
	unsigned int incounts[2];
	unsigned long flags;
	int stat;
	inbuf[0] = enable ? ATMEL_WREN : ATMEL_WRDI;
	inbufs[0] = inbuf;
	incounts[0] = sizeof(inbuf);
	incounts[1] = 0;
	spin_lock_irqsave(&spi_eeprom_lock, flags);
	stat = spi_eeprom_io(chipid, inbufs, incounts, NULL, NULL);
	spin_unlock_irqrestore(&spi_eeprom_lock, flags);
	return stat;
}

static int spi_eeprom_read_status_nolock(int chipid)
{
	unsigned char inbuf[2], outbuf[2];
	unsigned char *inbufs[1], *outbufs[1];
	unsigned int incounts[2], outcounts[2];
	int stat;
	inbuf[0] = ATMEL_RDSR;
	inbuf[1] = 0;
	inbufs[0] = inbuf;
	incounts[0] = sizeof(inbuf);
	incounts[1] = 0;
	outbufs[0] = outbuf;
	outcounts[0] = sizeof(outbuf);
	outcounts[1] = 0;
	stat = spi_eeprom_io(chipid, inbufs, incounts, outbufs, outcounts);
	if (stat < 0)
		return stat;
	return outbuf[1];
}

int spi_eeprom_read_status(int chipid)
{
	unsigned long flags;
	int stat;
	spin_lock_irqsave(&spi_eeprom_lock, flags);
	stat = spi_eeprom_read_status_nolock(chipid);
	spin_unlock_irqrestore(&spi_eeprom_lock, flags);
	return stat;
}

int spi_eeprom_read(int chipid, int address, unsigned char *buf, int len)
{
	unsigned char inbuf[2];
	unsigned char *inbufs[2], *outbufs[2];
	unsigned int incounts[2], outcounts[3];
	unsigned long flags;
	int stat;
	inbuf[0] = ATMEL_READ;
	inbuf[1] = address;
	inbufs[0] = inbuf;
	inbufs[1] = NULL;
	incounts[0] = sizeof(inbuf);
	incounts[1] = 0;
	outbufs[0] = NULL;
	outbufs[1] = buf;
	outcounts[0] = 2;
	outcounts[1] = len;
	outcounts[2] = 0;
	spin_lock_irqsave(&spi_eeprom_lock, flags);
	stat = spi_eeprom_io(chipid, inbufs, incounts, outbufs, outcounts);
	spin_unlock_irqrestore(&spi_eeprom_lock, flags);
	return stat;
}

int spi_eeprom_write(int chipid, int address, unsigned char *buf, int len)
{
	unsigned char inbuf[2];
	unsigned char *inbufs[2];
	unsigned int incounts[3];
	unsigned long flags;
	int i, stat;

	if (address / 8 != (address + len - 1) / 8)
		return -EINVAL;
	stat = spi_eeprom_write_enable(chipid, 1);
	if (stat < 0)
		return stat;
	stat = spi_eeprom_read_status(chipid);
	if (stat < 0)
		return stat;
	if (!(stat & ATMEL_SR_WEN))
		return -EPERM;

	inbuf[0] = ATMEL_WRITE;
	inbuf[1] = address;
	inbufs[0] = inbuf;
	inbufs[1] = buf;
	incounts[0] = sizeof(inbuf);
	incounts[1] = len;
	incounts[2] = 0;
	spin_lock_irqsave(&spi_eeprom_lock, flags);
	stat = spi_eeprom_io(chipid, inbufs, incounts, NULL, NULL);
	if (stat < 0)
		goto unlock_return;

	/* write start.  max 10ms */
	for (i = 10; i > 0; i--) {
		int stat = spi_eeprom_read_status_nolock(chipid);
		if (stat < 0)
			goto unlock_return;
		if (!(stat & ATMEL_SR_BSY))
			break;
		mdelay(1);
	}
	spin_unlock_irqrestore(&spi_eeprom_lock, flags);
	if (i == 0)
		return -EIO;
	return len;
 unlock_return:
	spin_unlock_irqrestore(&spi_eeprom_lock, flags);
	return stat;
}

#ifdef CONFIG_PROC_FS
#define MAX_SIZE	0x80	/* for ATMEL 25010 */
static int spi_eeprom_read_proc(char *page, char **start, off_t off,
				int count, int *eof, void *data)
{
	unsigned int size = MAX_SIZE;
	if (spi_eeprom_read((int)data, 0, (unsigned char *)page, size) < 0)
		size = 0;
	return size;
}

static int spi_eeprom_write_proc(struct file *file, const char *buffer,
				 unsigned long count, void *data)
{
	unsigned int size = MAX_SIZE;
	int i;
	if (file->f_pos >= size)
		return -EIO;
	if (file->f_pos + count > size)
		count = size - file->f_pos;
	for (i = 0; i < count; i += 8) {
		int len = count - i < 8 ? count - i : 8;
		if (spi_eeprom_write((int)data, file->f_pos,
				     (unsigned char *)buffer, len) < 0) {
			count = -EIO;
			break;
		}
		buffer += len;
		file->f_pos += len;
	}
	return count;
}

__init void spi_eeprom_proc_create(struct proc_dir_entry *dir, int chipid)
{
	struct proc_dir_entry *entry;
	char name[128];
	sprintf(name, "seeprom-%d", chipid);
	entry = create_proc_entry(name, 0600, dir);
	if (entry) {
		entry->read_proc = spi_eeprom_read_proc;
		entry->write_proc = spi_eeprom_write_proc;
		entry->data = (void *)chipid;
	}
}
#endif /* CONFIG_PROC_FS */