summaryrefslogtreecommitdiffstats
path: root/drivers/i2c/pca9564_i2c.c
blob: 313288dd112b0e8c3e6f1c553019697ec0346785 (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
/*
 * File:         drivers/i2c/pca9564.c
 * Based on:     drivers/i2c/s3c44b0_i2c.c
 * Author:
 *
 * Created:      2009-06-23
 * Description:  PCA9564 i2c bridge driver
 *
 * Modified:
 *               Copyright 2009 CJSC "NII STT", http://www.niistt.ru/
 *
 * Bugs:
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <i2c.h>
#include <pca9564.h>
#include <asm/io.h>

#define PCA_STA			(CONFIG_PCA9564_BASE + 0)
#define PCA_TO			(CONFIG_PCA9564_BASE + 0)
#define PCA_DAT			(CONFIG_PCA9564_BASE + (1 << 2))
#define PCA_ADR			(CONFIG_PCA9564_BASE + (2 << 2))
#define PCA_CON			(CONFIG_PCA9564_BASE + (3 << 2))

static unsigned char pca_read_reg(unsigned int reg)
{
	return readb((void *)reg);
}

static void pca_write_reg(unsigned int reg, unsigned char value)
{
	writeb(value, (void *)reg);
}

static int pca_wait_busy(void)
{
	unsigned int timeout = 10000;

	while (!(pca_read_reg(PCA_CON) & PCA_CON_SI) && --timeout)
		udelay(1);

	if (timeout == 0)
		debug("I2C timeout!\n");

	debug("CON = 0x%02x, STA = 0x%02x\n", pca_read_reg(PCA_CON),
	       pca_read_reg(PCA_STA));

	return timeout ? 0 : 1;
}

/*=====================================================================*/
/*                         Public Functions                            */
/*=====================================================================*/

/*-----------------------------------------------------------------------
 * Initialization
 */
void i2c_init(int speed, int slaveaddr)
{
	pca_write_reg(PCA_CON, PCA_CON_ENSIO | speed);
}

/*
 * Probe the given I2C chip address.  Returns 0 if a chip responded,
 * not 0 on failure.
 */

int i2c_probe(uchar chip)
{
	unsigned char res;

	pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO);
	pca_wait_busy();

	pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO);

	pca_write_reg(PCA_DAT, (chip << 1) | 1);
	res = pca_wait_busy();

	if ((res == 0) && (pca_read_reg(PCA_STA) == 0x48))
		res = 1;

	pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO);

	return res;
}

/*
 * Read/Write interface:
 *   chip:    I2C chip address, range 0..127
 *   addr:    Memory (register) address within the chip
 *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
 *              memories, 0 for register type devices with only one
 *              register)
 *   buffer:  Where to read/write the data
 *   len:     How many bytes to read/write
 *
 *   Returns: 0 on success, not 0 on failure
 */
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
	int i;

	pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
	pca_wait_busy();

	pca_write_reg(PCA_CON, PCA_CON_ENSIO);

	pca_write_reg(PCA_DAT, (chip << 1));
	pca_wait_busy();
	pca_write_reg(PCA_CON, PCA_CON_ENSIO);

	if (alen > 0) {
		pca_write_reg(PCA_DAT, addr);
		pca_wait_busy();
		pca_write_reg(PCA_CON, PCA_CON_ENSIO);
	}

	pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO);

	udelay(500);

	pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
	pca_wait_busy();
	pca_write_reg(PCA_CON, PCA_CON_ENSIO);

	pca_write_reg(PCA_DAT, (chip << 1) | 1);
	pca_wait_busy();

	for (i = 0; i < len; ++i) {
		if (i == len - 1)
			pca_write_reg(PCA_CON, PCA_CON_ENSIO);
		else
			pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_AA);

		pca_wait_busy();
		buffer[i] = pca_read_reg(PCA_DAT);

	}

	pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO);

	return 0;
}

int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
	int i;

	pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
	pca_wait_busy();
	pca_write_reg(PCA_CON, PCA_CON_ENSIO);

	pca_write_reg(PCA_DAT, chip << 1);
	pca_wait_busy();
	pca_write_reg(PCA_CON, PCA_CON_ENSIO);

	if (alen > 0) {
		pca_write_reg(PCA_DAT, addr);
		pca_wait_busy();
		pca_write_reg(PCA_CON, PCA_CON_ENSIO);
	}

	for (i = 0; i < len; ++i) {
		pca_write_reg(PCA_DAT, buffer[i]);
		pca_wait_busy();
		pca_write_reg(PCA_CON, PCA_CON_ENSIO);
	}

	pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO);

	return 0;
}