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Valentin Yakovenkov08ea5502009-10-26 18:49:06 -04001/*
2 * File: drivers/i2c/pca9564.c
3 * Based on: drivers/i2c/s3c44b0_i2c.c
4 * Author:
5 *
6 * Created: 2009-06-23
7 * Description: PCA9564 i2c bridge driver
8 *
9 * Modified:
10 * Copyright 2009 CJSC "NII STT", http://www.niistt.ru/
11 *
12 * Bugs:
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, see the file COPYING, or write
26 * to the Free Software Foundation, Inc.,
27 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
28 */
29
30#include <common.h>
31#include <i2c.h>
32#include <pca9564.h>
33#include <asm/io.h>
34
35#define PCA_STA (CONFIG_PCA9564_BASE + 0)
36#define PCA_TO (CONFIG_PCA9564_BASE + 0)
37#define PCA_DAT (CONFIG_PCA9564_BASE + (1 << 2))
38#define PCA_ADR (CONFIG_PCA9564_BASE + (2 << 2))
39#define PCA_CON (CONFIG_PCA9564_BASE + (3 << 2))
40
41static unsigned char pca_read_reg(unsigned int reg)
42{
43 return readb((void *)reg);
44}
45
46static void pca_write_reg(unsigned int reg, unsigned char value)
47{
48 writeb(value, (void *)reg);
49}
50
51static int pca_wait_busy(void)
52{
53 unsigned int timeout = 10000;
54
55 while (!(pca_read_reg(PCA_CON) & PCA_CON_SI) && --timeout)
56 udelay(1);
57
58 if (timeout == 0)
59 debug("I2C timeout!\n");
60
61 debug("CON = 0x%02x, STA = 0x%02x\n", pca_read_reg(PCA_CON),
62 pca_read_reg(PCA_STA));
63
64 return timeout ? 0 : 1;
65}
66
67/*=====================================================================*/
68/* Public Functions */
69/*=====================================================================*/
70
71/*-----------------------------------------------------------------------
72 * Initialization
73 */
74void i2c_init(int speed, int slaveaddr)
75{
76 pca_write_reg(PCA_CON, PCA_CON_ENSIO | speed);
77}
78
79/*
80 * Probe the given I2C chip address. Returns 0 if a chip responded,
81 * not 0 on failure.
82 */
83
84int i2c_probe(uchar chip)
85{
86 unsigned char res;
87
88 pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO);
89 pca_wait_busy();
90
91 pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO);
92
93 pca_write_reg(PCA_DAT, (chip << 1) | 1);
94 res = pca_wait_busy();
95
96 if ((res == 0) && (pca_read_reg(PCA_STA) == 0x48))
97 res = 1;
98
99 pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO);
100
101 return res;
102}
103
104/*
105 * Read/Write interface:
106 * chip: I2C chip address, range 0..127
107 * addr: Memory (register) address within the chip
108 * alen: Number of bytes to use for addr (typically 1, 2 for larger
109 * memories, 0 for register type devices with only one
110 * register)
111 * buffer: Where to read/write the data
112 * len: How many bytes to read/write
113 *
114 * Returns: 0 on success, not 0 on failure
115 */
116int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
117{
118 int i;
119
120 pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
121 pca_wait_busy();
122
123 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
124
125 pca_write_reg(PCA_DAT, (chip << 1));
126 pca_wait_busy();
127 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
128
129 if (alen > 0) {
130 pca_write_reg(PCA_DAT, addr);
131 pca_wait_busy();
132 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
133 }
134
135 pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO);
136
137 udelay(500);
138
139 pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
140 pca_wait_busy();
141 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
142
143 pca_write_reg(PCA_DAT, (chip << 1) | 1);
144 pca_wait_busy();
145
146 for (i = 0; i < len; ++i) {
147 if (i == len - 1)
148 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
149 else
150 pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_AA);
151
152 pca_wait_busy();
153 buffer[i] = pca_read_reg(PCA_DAT);
154
155 }
156
157 pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO);
158
159 return 0;
160}
161
162int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
163{
164 int i;
165
166 pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
167 pca_wait_busy();
168 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
169
170 pca_write_reg(PCA_DAT, chip << 1);
171 pca_wait_busy();
172 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
173
174 if (alen > 0) {
175 pca_write_reg(PCA_DAT, addr);
176 pca_wait_busy();
177 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
178 }
179
180 for (i = 0; i < len; ++i) {
181 pca_write_reg(PCA_DAT, buffer[i]);
182 pca_wait_busy();
183 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
184 }
185
186 pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO);
187
188 return 0;
189}