1#include <common.h>
2#include <mpc8xx.h>
3#include <malloc.h>
4#include <galileo/gt64260R.h>
5#include <galileo/core.h>
6
7#define MAX_I2C_RETRYS 10
8#define I2C_DELAY 1000
9#undef DEBUG_I2C
10
11#ifdef DEBUG_I2C
12#define DP(x) x
13#else
14#define DP(x)
15#endif
16
17
18
19static void
20i2c_init(int speed, int slaveaddr)
21{
22 unsigned int n, m, freq, margin, power;
23 unsigned int actualFreq, actualN=0, actualM=0;
24 unsigned int control, status;
25 unsigned int minMargin = 0xffffffff;
26 unsigned int tclk = 125000000;
27
28 DP(puts("i2c_init\n"));
29
30 for(n = 0 ; n < 8 ; n++)
31 {
32 for(m = 0 ; m < 16 ; m++)
33 {
34 power = 2<<n;
35 freq = tclk/(10*(m+1)*power);
36 if (speed > freq)
37 margin = speed - freq;
38 else
39 margin = freq - speed;
40 if(margin < minMargin)
41 {
42 minMargin = margin;
43 actualFreq = freq;
44 actualN = n;
45 actualM = m;
46 }
47 }
48 }
49
50 DP(puts("setup i2c bus\n"));
51
52
53
54 GT_REG_WRITE(I2C_SOFT_RESET, 0);
55
56 DP(puts("udelay...\n"));
57
58 udelay(I2C_DELAY);
59
60 DP(puts("set baudrate\n"));
61
62 GT_REG_WRITE(I2C_STATUS_BAUDE_RATE, (actualM << 3) | actualN);
63 GT_REG_WRITE(I2C_CONTROL, (0x1 << 2) | (0x1 << 6));
64
65 udelay(I2C_DELAY * 10);
66
67 DP(puts("read control, baudrate\n"));
68
69 GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
70 GT_REG_READ(I2C_CONTROL, &control);
71}
72
73static uchar
74i2c_start(void)
75{
76 unsigned int control, status;
77 int count = 0;
78
79 DP(puts("i2c_start\n"));
80
81
82
83 GT_REG_READ(I2C_CONTROL, &control);
84 control |= (0x1 << 5);
85 GT_REG_WRITE(I2C_CONTROL, control);
86
87 GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
88
89 count = 0;
90 while ((status & 0xff) != 0x08) {
91 udelay(I2C_DELAY);
92 if (count > 20) {
93 GT_REG_WRITE(I2C_CONTROL, (0x1 << 4));
94 return (status);
95 }
96 GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
97 count++;
98 }
99
100 return (0);
101}
102
103static uchar
104i2c_select_device(uchar dev_addr, uchar read, int ten_bit)
105{
106 unsigned int status, data, bits = 7;
107 int count = 0;
108
109 DP(puts("i2c_select_device\n"));
110
111
112
113 if (ten_bit) {
114 bits = 10;
115 }
116
117 data = (dev_addr << 1);
118
119 data |= read;
120 GT_REG_WRITE(I2C_DATA, data);
121
122 RESET_REG_BITS(I2C_CONTROL, BIT3);
123
124 udelay(I2C_DELAY);
125
126 GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
127 count = 0;
128 while (((status & 0xff) != 0x40) && ((status & 0xff) != 0x18)) {
129 udelay(I2C_DELAY);
130 if (count > 20) {
131 GT_REG_WRITE(I2C_CONTROL, (0x1 << 4));
132 return(status);
133 }
134 GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
135 count++;
136 }
137
138 if (bits == 10) {
139 printf("10 bit I2C addressing not yet implemented\n");
140 return (0xff);
141 }
142
143 return (0);
144}
145
146static uchar
147i2c_get_data(uchar* return_data, int len) {
148
149 unsigned int data, status = 0;
150 int count = 0;
151
152 DP(puts("i2c_get_data\n"));
153
154 while (len) {
155
156
157
158 RESET_REG_BITS(I2C_CONTROL, (0x1 << 3));
159
160 udelay(I2C_DELAY * 5);
161
162 GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
163 count++;
164 while ((status & 0xff) != 0x50) {
165 udelay(I2C_DELAY);
166 if(count > 2) {
167 GT_REG_WRITE(I2C_CONTROL, (0x1 << 4));
168 return 0;
169 }
170 GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
171 count++;
172 }
173 GT_REG_READ(I2C_DATA, &data);
174 len--;
175 *return_data = (uchar)data;
176 return_data++;
177 }
178 RESET_REG_BITS(I2C_CONTROL, BIT2|BIT3);
179 while ((status & 0xff) != 0x58) {
180 udelay(I2C_DELAY);
181 if(count > 200) {
182 GT_REG_WRITE(I2C_CONTROL, (0x1 << 4));
183 return (status);
184 }
185 GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
186 count++;
187 }
188 GT_REG_WRITE(I2C_CONTROL, (0x1 << 4));
189
190 return (0);
191}
192
193static uchar
194i2c_write_data(unsigned int data, int len)
195{
196 unsigned int status;
197 int count = 0;
198
199 DP(puts("i2c_write_data\n"));
200
201 if (len > 4)
202 return -1;
203
204 while (len) {
205
206
207 GT_REG_WRITE(I2C_DATA, (unsigned int)data);
208 RESET_REG_BITS(I2C_CONTROL, (0x1 << 3));
209
210 udelay(I2C_DELAY);
211
212 GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
213 count++;
214 while ((status & 0xff) != 0x28) {
215 udelay(I2C_DELAY);
216 if(count > 20) {
217 GT_REG_WRITE(I2C_CONTROL, (0x1 << 4));
218 return (status);
219 }
220 GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
221 count++;
222 }
223 len--;
224 }
225 GT_REG_WRITE(I2C_CONTROL, (0x1 << 3) | (0x1 << 4));
226 GT_REG_WRITE(I2C_CONTROL, (0x1 << 4));
227
228 udelay(I2C_DELAY * 10);
229
230 return (0);
231}
232
233static uchar
234i2c_set_dev_offset(uchar dev_addr, unsigned int offset, int ten_bit)
235{
236 uchar status;
237
238 DP(puts("i2c_set_dev_offset\n"));
239
240 status = i2c_select_device(dev_addr, 0, ten_bit);
241 if (status) {
242#ifdef DEBUG_I2C
243 printf("Failed to select device setting offset: 0x%02x\n",
244 status);
245#endif
246 return status;
247 }
248
249 status = i2c_write_data(offset, 1);
250 if (status) {
251#ifdef DEBUG_I2C
252 printf("Failed to write data: 0x%02x\n", status);
253#endif
254 return status;
255 }
256
257 return (0);
258}
259
260uchar
261i2c_read(uchar dev_addr, unsigned int offset, int len, uchar* data,
262 int ten_bit)
263{
264 uchar status = 0;
265 unsigned int i2cFreq = 400000;
266
267 DP(puts("i2c_read\n"));
268
269 i2c_init(i2cFreq,0);
270
271 status = i2c_start();
272
273 if (status) {
274#ifdef DEBUG_I2C
275 printf("Transaction start failed: 0x%02x\n", status);
276#endif
277 return status;
278 }
279
280 status = i2c_set_dev_offset(dev_addr, 0, 0);
281 if (status) {
282#ifdef DEBUG_I2C
283 printf("Failed to set offset: 0x%02x\n", status);
284#endif
285 return status;
286 }
287
288 i2c_init(i2cFreq,0);
289
290 status = i2c_start();
291 if (status) {
292#ifdef DEBUG_I2C
293 printf("Transaction restart failed: 0x%02x\n", status);
294#endif
295 return status;
296 }
297
298 status = i2c_select_device(dev_addr, 1, ten_bit);
299 if (status) {
300#ifdef DEBUG_I2C
301 printf("Address not acknowledged: 0x%02x\n", status);
302#endif
303 return status;
304 }
305
306 status = i2c_get_data(data, len);
307 if (status) {
308#ifdef DEBUG_I2C
309 printf("Data not recieved: 0x%02x\n", status);
310#endif
311 return status;
312 }
313
314 return 0;
315}
316
