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1 /*
2  * (C) Copyright 2009
3  * Heiko Schocher, DENX Software Engineering, hs@denx.de.
4  * Changes for multibus/multiadapter I2C support.
5  *
6  * (C) Copyright 2001, 2002
7  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
8  *
9  * SPDX-License-Identifier:     GPL-2.0+
10  *
11  * This has been changed substantially by Gerald Van Baren, Custom IDEAS,
12  * vanbaren@cideas.com.  It was heavily influenced by LiMon, written by
13  * Neil Russell.
14  */
15
16 #include <common.h>
17 #ifdef  CONFIG_MPC8260                  /* only valid for MPC8260 */
18 #include <ioports.h>
19 #include <asm/io.h>
20 #endif
21 #if defined(CONFIG_AVR32)
22 #include <asm/arch/portmux.h>
23 #endif
24 #if defined(CONFIG_AT91FAMILY)
25 #include <asm/io.h>
26 #include <asm/arch/hardware.h>
27 #include <asm/arch/at91_pio.h>
28 #ifdef CONFIG_ATMEL_LEGACY
29 #include <asm/arch/gpio.h>
30 #endif
31 #endif
32 #if defined(CONFIG_MPC852T) || defined(CONFIG_MPC866)
33 #include <asm/io.h>
34 #endif
35 #include <i2c.h>
36
37 #if defined(CONFIG_SOFT_I2C_GPIO_SCL)
38 # include <asm/gpio.h>
39
40 # ifndef I2C_GPIO_SYNC
41 #  define I2C_GPIO_SYNC
42 # endif
43
44 # ifndef I2C_INIT
45 #  define I2C_INIT \
46         do { \
47                 gpio_request(CONFIG_SOFT_I2C_GPIO_SCL, "soft_i2c"); \
48                 gpio_request(CONFIG_SOFT_I2C_GPIO_SDA, "soft_i2c"); \
49         } while (0)
50 # endif
51
52 # ifndef I2C_ACTIVE
53 #  define I2C_ACTIVE do { } while (0)
54 # endif
55
56 # ifndef I2C_TRISTATE
57 #  define I2C_TRISTATE do { } while (0)
58 # endif
59
60 # ifndef I2C_READ
61 #  define I2C_READ gpio_get_value(CONFIG_SOFT_I2C_GPIO_SDA)
62 # endif
63
64 # ifndef I2C_SDA
65 #  define I2C_SDA(bit) \
66         do { \
67                 if (bit) \
68                         gpio_direction_input(CONFIG_SOFT_I2C_GPIO_SDA); \
69                 else \
70                         gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SDA, 0); \
71                 I2C_GPIO_SYNC; \
72         } while (0)
73 # endif
74
75 # ifndef I2C_SCL
76 #  define I2C_SCL(bit) \
77         do { \
78                 gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SCL, bit); \
79                 I2C_GPIO_SYNC; \
80         } while (0)
81 # endif
82
83 # ifndef I2C_DELAY
84 #  define I2C_DELAY udelay(5)   /* 1/4 I2C clock duration */
85 # endif
86
87 #endif
88
89 /* #define      DEBUG_I2C       */
90
91 DECLARE_GLOBAL_DATA_PTR;
92
93 #ifndef I2C_SOFT_DECLARATIONS
94 # if defined(CONFIG_MPC8260)
95 #  define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = \
96                 ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
97 # elif defined(CONFIG_8xx)
98 #  define I2C_SOFT_DECLARATIONS volatile immap_t *immr = \
99                 (immap_t *)CONFIG_SYS_IMMR;
100 # else
101 #  define I2C_SOFT_DECLARATIONS
102 # endif
103 #endif
104
105 #if !defined(CONFIG_SYS_I2C_SOFT_SPEED)
106 #define CONFIG_SYS_I2C_SOFT_SPEED CONFIG_SYS_I2C_SPEED
107 #endif
108 #if !defined(CONFIG_SYS_I2C_SOFT_SLAVE)
109 #define CONFIG_SYS_I2C_SOFT_SLAVE CONFIG_SYS_I2C_SLAVE
110 #endif
111
112 /*-----------------------------------------------------------------------
113  * Definitions
114  */
115 #define RETRIES         0
116
117 #define I2C_ACK         0               /* PD_SDA level to ack a byte */
118 #define I2C_NOACK       1               /* PD_SDA level to noack a byte */
119
120
121 #ifdef DEBUG_I2C
122 #define PRINTD(fmt,args...)     do {    \
123                 printf (fmt ,##args);   \
124         } while (0)
125 #else
126 #define PRINTD(fmt,args...)
127 #endif
128
129 /*-----------------------------------------------------------------------
130  * Local functions
131  */
132 #if !defined(CONFIG_SYS_I2C_INIT_BOARD)
133 static void  send_reset (void);
134 #endif
135 static void  send_start (void);
136 static void  send_stop  (void);
137 static void  send_ack   (int);
138 static int   write_byte (uchar byte);
139 static uchar read_byte  (int);
140
141 #if !defined(CONFIG_SYS_I2C_INIT_BOARD)
142 /*-----------------------------------------------------------------------
143  * Send a reset sequence consisting of 9 clocks with the data signal high
144  * to clock any confused device back into an idle state.  Also send a
145  * <stop> at the end of the sequence for belts & suspenders.
146  */
147 static void send_reset(void)
148 {
149         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
150         int j;
151
152         I2C_SCL(1);
153         I2C_SDA(1);
154 #ifdef  I2C_INIT
155         I2C_INIT;
156 #endif
157         I2C_TRISTATE;
158         for(j = 0; j < 9; j++) {
159                 I2C_SCL(0);
160                 I2C_DELAY;
161                 I2C_DELAY;
162                 I2C_SCL(1);
163                 I2C_DELAY;
164                 I2C_DELAY;
165         }
166         send_stop();
167         I2C_TRISTATE;
168 }
169 #endif
170
171 /*-----------------------------------------------------------------------
172  * START: High -> Low on SDA while SCL is High
173  */
174 static void send_start(void)
175 {
176         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
177
178         I2C_DELAY;
179         I2C_SDA(1);
180         I2C_ACTIVE;
181         I2C_DELAY;
182         I2C_SCL(1);
183         I2C_DELAY;
184         I2C_SDA(0);
185         I2C_DELAY;
186 }
187
188 /*-----------------------------------------------------------------------
189  * STOP: Low -> High on SDA while SCL is High
190  */
191 static void send_stop(void)
192 {
193         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
194
195         I2C_SCL(0);
196         I2C_DELAY;
197         I2C_SDA(0);
198         I2C_ACTIVE;
199         I2C_DELAY;
200         I2C_SCL(1);
201         I2C_DELAY;
202         I2C_SDA(1);
203         I2C_DELAY;
204         I2C_TRISTATE;
205 }
206
207 /*-----------------------------------------------------------------------
208  * ack should be I2C_ACK or I2C_NOACK
209  */
210 static void send_ack(int ack)
211 {
212         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
213
214         I2C_SCL(0);
215         I2C_DELAY;
216         I2C_ACTIVE;
217         I2C_SDA(ack);
218         I2C_DELAY;
219         I2C_SCL(1);
220         I2C_DELAY;
221         I2C_DELAY;
222         I2C_SCL(0);
223         I2C_DELAY;
224 }
225
226 /*-----------------------------------------------------------------------
227  * Send 8 bits and look for an acknowledgement.
228  */
229 static int write_byte(uchar data)
230 {
231         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
232         int j;
233         int nack;
234
235         I2C_ACTIVE;
236         for(j = 0; j < 8; j++) {
237                 I2C_SCL(0);
238                 I2C_DELAY;
239                 I2C_SDA(data & 0x80);
240                 I2C_DELAY;
241                 I2C_SCL(1);
242                 I2C_DELAY;
243                 I2C_DELAY;
244
245                 data <<= 1;
246         }
247
248         /*
249          * Look for an <ACK>(negative logic) and return it.
250          */
251         I2C_SCL(0);
252         I2C_DELAY;
253         I2C_SDA(1);
254         I2C_TRISTATE;
255         I2C_DELAY;
256         I2C_SCL(1);
257         I2C_DELAY;
258         I2C_DELAY;
259         nack = I2C_READ;
260         I2C_SCL(0);
261         I2C_DELAY;
262         I2C_ACTIVE;
263
264         return(nack);   /* not a nack is an ack */
265 }
266
267 /*-----------------------------------------------------------------------
268  * if ack == I2C_ACK, ACK the byte so can continue reading, else
269  * send I2C_NOACK to end the read.
270  */
271 static uchar read_byte(int ack)
272 {
273         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
274         int  data;
275         int  j;
276
277         /*
278          * Read 8 bits, MSB first.
279          */
280         I2C_TRISTATE;
281         I2C_SDA(1);
282         data = 0;
283         for(j = 0; j < 8; j++) {
284                 I2C_SCL(0);
285                 I2C_DELAY;
286                 I2C_SCL(1);
287                 I2C_DELAY;
288                 data <<= 1;
289                 data |= I2C_READ;
290                 I2C_DELAY;
291         }
292         send_ack(ack);
293
294         return(data);
295 }
296
297 /*-----------------------------------------------------------------------
298  * Initialization
299  */
300 static void soft_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
301 {
302 #if defined(CONFIG_SYS_I2C_INIT_BOARD)
303         /* call board specific i2c bus reset routine before accessing the   */
304         /* environment, which might be in a chip on that bus. For details   */
305         /* about this problem see doc/I2C_Edge_Conditions.                  */
306         i2c_init_board();
307 #else
308         /*
309          * WARNING: Do NOT save speed in a static variable: if the
310          * I2C routines are called before RAM is initialized (to read
311          * the DIMM SPD, for instance), RAM won't be usable and your
312          * system will crash.
313          */
314         send_reset ();
315 #endif
316 }
317
318 /*-----------------------------------------------------------------------
319  * Probe to see if a chip is present.  Also good for checking for the
320  * completion of EEPROM writes since the chip stops responding until
321  * the write completes (typically 10mSec).
322  */
323 static int soft_i2c_probe(struct i2c_adapter *adap, uint8_t addr)
324 {
325         int rc;
326
327         /*
328          * perform 1 byte write transaction with just address byte
329          * (fake write)
330          */
331         send_start();
332         rc = write_byte ((addr << 1) | 0);
333         send_stop();
334
335         return (rc ? 1 : 0);
336 }
337
338 /*-----------------------------------------------------------------------
339  * Read bytes
340  */
341 static int  soft_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
342                         int alen, uchar *buffer, int len)
343 {
344         int shift;
345         PRINTD("i2c_read: chip %02X addr %02X alen %d buffer %p len %d\n",
346                 chip, addr, alen, buffer, len);
347
348 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
349         /*
350          * EEPROM chips that implement "address overflow" are ones
351          * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
352          * address and the extra bits end up in the "chip address"
353          * bit slots. This makes a 24WC08 (1Kbyte) chip look like
354          * four 256 byte chips.
355          *
356          * Note that we consider the length of the address field to
357          * still be one byte because the extra address bits are
358          * hidden in the chip address.
359          */
360         chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
361
362         PRINTD("i2c_read: fix addr_overflow: chip %02X addr %02X\n",
363                 chip, addr);
364 #endif
365
366         /*
367          * Do the addressing portion of a write cycle to set the
368          * chip's address pointer.  If the address length is zero,
369          * don't do the normal write cycle to set the address pointer,
370          * there is no address pointer in this chip.
371          */
372         send_start();
373         if(alen > 0) {
374                 if(write_byte(chip << 1)) {     /* write cycle */
375                         send_stop();
376                         PRINTD("i2c_read, no chip responded %02X\n", chip);
377                         return(1);
378                 }
379                 shift = (alen-1) * 8;
380                 while(alen-- > 0) {
381                         if(write_byte(addr >> shift)) {
382                                 PRINTD("i2c_read, address not <ACK>ed\n");
383                                 return(1);
384                         }
385                         shift -= 8;
386                 }
387
388                 /* Some I2C chips need a stop/start sequence here,
389                  * other chips don't work with a full stop and need
390                  * only a start.  Default behaviour is to send the
391                  * stop/start sequence.
392                  */
393 #ifdef CONFIG_SOFT_I2C_READ_REPEATED_START
394                 send_start();
395 #else
396                 send_stop();
397                 send_start();
398 #endif
399         }
400         /*
401          * Send the chip address again, this time for a read cycle.
402          * Then read the data.  On the last byte, we do a NACK instead
403          * of an ACK(len == 0) to terminate the read.
404          */
405         write_byte((chip << 1) | 1);    /* read cycle */
406         while(len-- > 0) {
407                 *buffer++ = read_byte(len == 0);
408         }
409         send_stop();
410         return(0);
411 }
412
413 /*-----------------------------------------------------------------------
414  * Write bytes
415  */
416 static int  soft_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
417                         int alen, uchar *buffer, int len)
418 {
419         int shift, failures = 0;
420
421         PRINTD("i2c_write: chip %02X addr %02X alen %d buffer %p len %d\n",
422                 chip, addr, alen, buffer, len);
423
424         send_start();
425         if(write_byte(chip << 1)) {     /* write cycle */
426                 send_stop();
427                 PRINTD("i2c_write, no chip responded %02X\n", chip);
428                 return(1);
429         }
430         shift = (alen-1) * 8;
431         while(alen-- > 0) {
432                 if(write_byte(addr >> shift)) {
433                         PRINTD("i2c_write, address not <ACK>ed\n");
434                         return(1);
435                 }
436                 shift -= 8;
437         }
438
439         while(len-- > 0) {
440                 if(write_byte(*buffer++)) {
441                         failures++;
442                 }
443         }
444         send_stop();
445         return(failures);
446 }
447
448 /*
449  * Register soft i2c adapters
450  */
451 U_BOOT_I2C_ADAP_COMPLETE(soft0, soft_i2c_init, soft_i2c_probe,
452                          soft_i2c_read, soft_i2c_write, NULL,
453                          CONFIG_SYS_I2C_SOFT_SPEED, CONFIG_SYS_I2C_SOFT_SLAVE,
454                          0)
455 #if defined(I2C_SOFT_DECLARATIONS2)
456 U_BOOT_I2C_ADAP_COMPLETE(soft1, soft_i2c_init, soft_i2c_probe,
457                          soft_i2c_read, soft_i2c_write, NULL,
458                          CONFIG_SYS_I2C_SOFT_SPEED_2,
459                          CONFIG_SYS_I2C_SOFT_SLAVE_2,
460                          1)
461 #endif
462 #if defined(I2C_SOFT_DECLARATIONS3)
463 U_BOOT_I2C_ADAP_COMPLETE(soft2, soft_i2c_init, soft_i2c_probe,
464                          soft_i2c_read, soft_i2c_write, NULL,
465                          CONFIG_SYS_I2C_SOFT_SPEED_3,
466                          CONFIG_SYS_I2C_SOFT_SLAVE_3,
467                          2)
468 #endif
469 #if defined(I2C_SOFT_DECLARATIONS4)
470 U_BOOT_I2C_ADAP_COMPLETE(soft3, soft_i2c_init, soft_i2c_probe,
471                          soft_i2c_read, soft_i2c_write, NULL,
472                          CONFIG_SYS_I2C_SOFT_SPEED_4,
473                          CONFIG_SYS_I2C_SOFT_SLAVE_4,
474                          3)
475 #endif