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08ea550e VY |
1 | /* |
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 | * | |
1a459660 | 14 | * SPDX-License-Identifier: GPL-2.0+ |
08ea550e VY |
15 | */ |
16 | ||
17 | #include <common.h> | |
18 | #include <i2c.h> | |
19 | #include <pca9564.h> | |
20 | #include <asm/io.h> | |
21 | ||
22 | #define PCA_STA (CONFIG_PCA9564_BASE + 0) | |
23 | #define PCA_TO (CONFIG_PCA9564_BASE + 0) | |
24 | #define PCA_DAT (CONFIG_PCA9564_BASE + (1 << 2)) | |
25 | #define PCA_ADR (CONFIG_PCA9564_BASE + (2 << 2)) | |
26 | #define PCA_CON (CONFIG_PCA9564_BASE + (3 << 2)) | |
27 | ||
28 | static unsigned char pca_read_reg(unsigned int reg) | |
29 | { | |
30 | return readb((void *)reg); | |
31 | } | |
32 | ||
33 | static void pca_write_reg(unsigned int reg, unsigned char value) | |
34 | { | |
35 | writeb(value, (void *)reg); | |
36 | } | |
37 | ||
38 | static int pca_wait_busy(void) | |
39 | { | |
40 | unsigned int timeout = 10000; | |
41 | ||
42 | while (!(pca_read_reg(PCA_CON) & PCA_CON_SI) && --timeout) | |
43 | udelay(1); | |
44 | ||
45 | if (timeout == 0) | |
46 | debug("I2C timeout!\n"); | |
47 | ||
48 | debug("CON = 0x%02x, STA = 0x%02x\n", pca_read_reg(PCA_CON), | |
49 | pca_read_reg(PCA_STA)); | |
50 | ||
51 | return timeout ? 0 : 1; | |
52 | } | |
53 | ||
54 | /*=====================================================================*/ | |
55 | /* Public Functions */ | |
56 | /*=====================================================================*/ | |
57 | ||
58 | /*----------------------------------------------------------------------- | |
59 | * Initialization | |
60 | */ | |
61 | void i2c_init(int speed, int slaveaddr) | |
62 | { | |
63 | pca_write_reg(PCA_CON, PCA_CON_ENSIO | speed); | |
64 | } | |
65 | ||
66 | /* | |
67 | * Probe the given I2C chip address. Returns 0 if a chip responded, | |
68 | * not 0 on failure. | |
69 | */ | |
70 | ||
71 | int i2c_probe(uchar chip) | |
72 | { | |
73 | unsigned char res; | |
74 | ||
75 | pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO); | |
76 | pca_wait_busy(); | |
77 | ||
78 | pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO); | |
79 | ||
80 | pca_write_reg(PCA_DAT, (chip << 1) | 1); | |
81 | res = pca_wait_busy(); | |
82 | ||
83 | if ((res == 0) && (pca_read_reg(PCA_STA) == 0x48)) | |
84 | res = 1; | |
85 | ||
86 | pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO); | |
87 | ||
88 | return res; | |
89 | } | |
90 | ||
91 | /* | |
92 | * Read/Write interface: | |
93 | * chip: I2C chip address, range 0..127 | |
94 | * addr: Memory (register) address within the chip | |
95 | * alen: Number of bytes to use for addr (typically 1, 2 for larger | |
96 | * memories, 0 for register type devices with only one | |
97 | * register) | |
98 | * buffer: Where to read/write the data | |
99 | * len: How many bytes to read/write | |
100 | * | |
101 | * Returns: 0 on success, not 0 on failure | |
102 | */ | |
103 | int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) | |
104 | { | |
105 | int i; | |
106 | ||
107 | pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA); | |
108 | pca_wait_busy(); | |
109 | ||
110 | pca_write_reg(PCA_CON, PCA_CON_ENSIO); | |
111 | ||
112 | pca_write_reg(PCA_DAT, (chip << 1)); | |
113 | pca_wait_busy(); | |
114 | pca_write_reg(PCA_CON, PCA_CON_ENSIO); | |
115 | ||
116 | if (alen > 0) { | |
117 | pca_write_reg(PCA_DAT, addr); | |
118 | pca_wait_busy(); | |
119 | pca_write_reg(PCA_CON, PCA_CON_ENSIO); | |
120 | } | |
121 | ||
122 | pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO); | |
123 | ||
124 | udelay(500); | |
125 | ||
126 | pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA); | |
127 | pca_wait_busy(); | |
128 | pca_write_reg(PCA_CON, PCA_CON_ENSIO); | |
129 | ||
130 | pca_write_reg(PCA_DAT, (chip << 1) | 1); | |
131 | pca_wait_busy(); | |
132 | ||
133 | for (i = 0; i < len; ++i) { | |
134 | if (i == len - 1) | |
135 | pca_write_reg(PCA_CON, PCA_CON_ENSIO); | |
136 | else | |
137 | pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_AA); | |
138 | ||
139 | pca_wait_busy(); | |
140 | buffer[i] = pca_read_reg(PCA_DAT); | |
141 | ||
142 | } | |
143 | ||
144 | pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO); | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
149 | int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) | |
150 | { | |
151 | int i; | |
152 | ||
153 | pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA); | |
154 | pca_wait_busy(); | |
155 | pca_write_reg(PCA_CON, PCA_CON_ENSIO); | |
156 | ||
157 | pca_write_reg(PCA_DAT, chip << 1); | |
158 | pca_wait_busy(); | |
159 | pca_write_reg(PCA_CON, PCA_CON_ENSIO); | |
160 | ||
161 | if (alen > 0) { | |
162 | pca_write_reg(PCA_DAT, addr); | |
163 | pca_wait_busy(); | |
164 | pca_write_reg(PCA_CON, PCA_CON_ENSIO); | |
165 | } | |
166 | ||
167 | for (i = 0; i < len; ++i) { | |
168 | pca_write_reg(PCA_DAT, buffer[i]); | |
169 | pca_wait_busy(); | |
170 | pca_write_reg(PCA_CON, PCA_CON_ENSIO); | |
171 | } | |
172 | ||
173 | pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO); | |
174 | ||
175 | return 0; | |
176 | } |