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24#include <common.h>
25
26DECLARE_GLOBAL_DATA_PTR;
27
28#ifdef CONFIG_HARD_I2C
29
30#include <mpc8220.h>
31#include <i2c.h>
32
33typedef struct mpc8220_i2c {
34 volatile u32 adr;
35 volatile u32 fdr;
36 volatile u32 cr;
37 volatile u32 sr;
38 volatile u32 dr;
39} i2c_t;
40
41
42#define I2C_EN 0x80
43#define I2C_IEN 0x40
44#define I2C_STA 0x20
45#define I2C_TX 0x10
46#define I2C_TXAK 0x08
47#define I2C_RSTA 0x04
48#define I2C_INIT_MASK (I2C_EN | I2C_STA | I2C_TX | I2C_RSTA)
49
50
51#define I2C_CF 0x80
52#define I2C_AAS 0x40
53#define I2C_BB 0x20
54#define I2C_AL 0x10
55#define I2C_SRW 0x04
56#define I2C_IF 0x02
57#define I2C_RXAK 0x01
58
59#define I2C_TIMEOUT 100
60#define I2C_RETRIES 1
61
62struct mpc8220_i2c_tap {
63 int scl2tap;
64 int tap2tap;
65};
66
67static int mpc_reg_in (volatile u32 * reg);
68static void mpc_reg_out (volatile u32 * reg, int val, int mask);
69static int wait_for_bb (void);
70static int wait_for_pin (int *status);
71static int do_address (uchar chip, char rdwr_flag);
72static int send_bytes (uchar chip, char *buf, int len);
73static int receive_bytes (uchar chip, char *buf, int len);
74static int mpc_get_fdr (int);
75
76static int mpc_reg_in (volatile u32 * reg)
77{
78 int ret;
79 ret = *reg >> 24;
80 __asm__ __volatile__ ("eieio");
81 return ret;
82}
83
84static void mpc_reg_out (volatile u32 * reg, int val, int mask)
85{
86 int tmp;
87
88 if (!mask) {
89 *reg = val << 24;
90 } else {
91 tmp = mpc_reg_in (reg);
92 *reg = ((tmp & ~mask) | (val & mask)) << 24;
93 }
94 __asm__ __volatile__ ("eieio");
95
96 return;
97}
98
99static int wait_for_bb (void)
100{
101 i2c_t *regs = (i2c_t *) MMAP_I2C;
102 int timeout = I2C_TIMEOUT;
103 int status;
104
105 status = mpc_reg_in (®s->sr);
106
107 while (timeout-- && (status & I2C_BB)) {
108#if 1
109 volatile int temp;
110
111 mpc_reg_out (®s->cr, I2C_STA, I2C_STA);
112 temp = mpc_reg_in (®s->dr);
113 mpc_reg_out (®s->cr, 0, I2C_STA);
114 mpc_reg_out (®s->cr, 0, 0);
115 mpc_reg_out (®s->cr, I2C_EN, 0);
116#endif
117 udelay (1000);
118 status = mpc_reg_in (®s->sr);
119 }
120
121 return (status & I2C_BB);
122}
123
124static int wait_for_pin (int *status)
125{
126 i2c_t *regs = (i2c_t *) MMAP_I2C;
127 int timeout = I2C_TIMEOUT;
128
129 *status = mpc_reg_in (®s->sr);
130
131 while (timeout-- && !(*status & I2C_IF)) {
132 udelay (1000);
133 *status = mpc_reg_in (®s->sr);
134 }
135
136 if (!(*status & I2C_IF)) {
137 return -1;
138 }
139
140 mpc_reg_out (®s->sr, 0, I2C_IF);
141 return 0;
142}
143
144static int do_address (uchar chip, char rdwr_flag)
145{
146 i2c_t *regs = (i2c_t *) MMAP_I2C;
147 int status;
148
149 chip <<= 1;
150
151 if (rdwr_flag)
152 chip |= 1;
153
154 mpc_reg_out (®s->cr, I2C_TX, I2C_TX);
155 mpc_reg_out (®s->dr, chip, 0);
156
157 if (wait_for_pin (&status))
158 return -2;
159 if (status & I2C_RXAK)
160 return -3;
161 return 0;
162}
163
164static int send_bytes (uchar chip, char *buf, int len)
165{
166 i2c_t *regs = (i2c_t *) MMAP_I2C;
167 int wrcount;
168 int status;
169
170 for (wrcount = 0; wrcount < len; ++wrcount) {
171
172 mpc_reg_out (®s->dr, buf[wrcount], 0);
173
174 if (wait_for_pin (&status))
175 break;
176
177 if (status & I2C_RXAK)
178 break;
179
180 }
181
182 return !(wrcount == len);
183 return 0;
184}
185
186static int receive_bytes (uchar chip, char *buf, int len)
187{
188 i2c_t *regs = (i2c_t *) MMAP_I2C;
189 int dummy = 1;
190 int rdcount = 0;
191 int status;
192 int i;
193
194 mpc_reg_out (®s->cr, 0, I2C_TX);
195
196 for (i = 0; i < len; ++i) {
197 buf[rdcount] = mpc_reg_in (®s->dr);
198
199 if (dummy)
200 dummy = 0;
201 else
202 rdcount++;
203
204 if (wait_for_pin (&status))
205 return -4;
206 }
207
208 mpc_reg_out (®s->cr, I2C_TXAK, I2C_TXAK);
209 buf[rdcount++] = mpc_reg_in (®s->dr);
210
211 if (wait_for_pin (&status))
212 return -5;
213
214 mpc_reg_out (®s->cr, 0, I2C_TXAK);
215 return 0;
216}
217
218
219
220void i2c_init (int speed, int saddr)
221{
222 i2c_t *regs = (i2c_t *) MMAP_I2C;
223
224 mpc_reg_out (®s->cr, 0, 0);
225 mpc_reg_out (®s->adr, saddr << 1, 0);
226
227
228
229 mpc_reg_out (®s->fdr, mpc_get_fdr (speed), 0);
230
231
232
233 mpc_reg_out (®s->cr, I2C_EN, I2C_INIT_MASK);
234 mpc_reg_out (®s->sr, 0, I2C_IF);
235 return;
236}
237
238static int mpc_get_fdr (int speed)
239{
240 static int fdr = -1;
241
242 if (fdr == -1) {
243 ulong best_speed = 0;
244 ulong divider;
245 ulong ipb, scl;
246 ulong bestmatch = 0xffffffffUL;
247 int best_i = 0, best_j = 0, i, j;
248 int SCL_Tap[] = { 9, 10, 12, 15, 5, 6, 7, 8 };
249 struct mpc8220_i2c_tap scltap[] = {
250 {4, 1},
251 {4, 2},
252 {6, 4},
253 {6, 8},
254 {14, 16},
255 {30, 32},
256 {62, 64},
257 {126, 128}
258 };
259
260 ipb = gd->bus_clk;
261 for (i = 7; i >= 0; i--) {
262 for (j = 7; j >= 0; j--) {
263 scl = 2 * (scltap[j].scl2tap +
264 (SCL_Tap[i] -
265 1) * scltap[j].tap2tap + 2);
266 if (ipb <= speed * scl) {
267 if ((speed * scl - ipb) < bestmatch) {
268 bestmatch = speed * scl - ipb;
269 best_i = i;
270 best_j = j;
271 best_speed = ipb / scl;
272 }
273 }
274 }
275 }
276 divider = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2);
277 if (gd->flags & GD_FLG_RELOC) {
278 fdr = divider;
279 } else {
280 printf ("%ld kHz, ", best_speed / 1000);
281 return divider;
282 }
283 }
284
285 return fdr;
286}
287
288int i2c_probe (uchar chip)
289{
290 i2c_t *regs = (i2c_t *) MMAP_I2C;
291 int i;
292
293 for (i = 0; i < I2C_RETRIES; i++) {
294 mpc_reg_out (®s->cr, I2C_STA, I2C_STA);
295
296 if (!do_address (chip, 0)) {
297 mpc_reg_out (®s->cr, 0, I2C_STA);
298 break;
299 }
300
301 mpc_reg_out (®s->cr, 0, I2C_STA);
302 udelay (50);
303 }
304
305 return (i == I2C_RETRIES);
306}
307
308int i2c_read (uchar chip, uint addr, int alen, uchar * buf, int len)
309{
310 uchar xaddr[4];
311 i2c_t *regs = (i2c_t *) MMAP_I2C;
312 int ret = -1;
313
314 xaddr[0] = (addr >> 24) & 0xFF;
315 xaddr[1] = (addr >> 16) & 0xFF;
316 xaddr[2] = (addr >> 8) & 0xFF;
317 xaddr[3] = addr & 0xFF;
318
319 if (wait_for_bb ()) {
320 printf ("i2c_read: bus is busy\n");
321 goto Done;
322 }
323
324 mpc_reg_out (®s->cr, I2C_STA, I2C_STA);
325 if (do_address (chip, 0)) {
326 printf ("i2c_read: failed to address chip\n");
327 goto Done;
328 }
329
330 if (send_bytes (chip, (char *)&xaddr[4 - alen], alen)) {
331 printf ("i2c_read: send_bytes failed\n");
332 goto Done;
333 }
334
335 mpc_reg_out (®s->cr, I2C_RSTA, I2C_RSTA);
336 if (do_address (chip, 1)) {
337 printf ("i2c_read: failed to address chip\n");
338 goto Done;
339 }
340
341 if (receive_bytes (chip, (char *)buf, len)) {
342 printf ("i2c_read: receive_bytes failed\n");
343 goto Done;
344 }
345
346 ret = 0;
347 Done:
348 mpc_reg_out (®s->cr, 0, I2C_STA);
349 return ret;
350}
351
352int i2c_write (uchar chip, uint addr, int alen, uchar * buf, int len)
353{
354 uchar xaddr[4];
355 i2c_t *regs = (i2c_t *) MMAP_I2C;
356 int ret = -1;
357
358 xaddr[0] = (addr >> 24) & 0xFF;
359 xaddr[1] = (addr >> 16) & 0xFF;
360 xaddr[2] = (addr >> 8) & 0xFF;
361 xaddr[3] = addr & 0xFF;
362
363 if (wait_for_bb ()) {
364 printf ("i2c_write: bus is busy\n");
365 goto Done;
366 }
367
368 mpc_reg_out (®s->cr, I2C_STA, I2C_STA);
369 if (do_address (chip, 0)) {
370 printf ("i2c_write: failed to address chip\n");
371 goto Done;
372 }
373
374 if (send_bytes (chip, (char *)&xaddr[4 - alen], alen)) {
375 printf ("i2c_write: send_bytes failed\n");
376 goto Done;
377 }
378
379 if (send_bytes (chip, (char *)buf, len)) {
380 printf ("i2c_write: send_bytes failed\n");
381 goto Done;
382 }
383
384 ret = 0;
385 Done:
386 mpc_reg_out (®s->cr, 0, I2C_STA);
387 return ret;
388}
389
390#endif
391
