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[J-u-boot.git] / drivers / i2c / soft_i2c.c
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c609719b 1/*
ea818dbb
HS		 2 * (C) Copyright 2009
3 * Heiko Schocher, DENX Software Engineering, [email protected].
4 * Changes for multibus/multiadapter I2C support.
5 *
c609719b
WD		 6 * (C) Copyright 2001, 2002
7 * Wolfgang Denk, DENX Software Engineering, [email protected].
8 *
1a459660 9 * SPDX-License-Identifier: GPL-2.0+
c609719b
WD		 10 *
11 * This has been changed substantially by Gerald Van Baren, Custom IDEAS,
12 * [email protected]. 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>
a21ca95f 19#include <asm/io.h>
c609719b 20#endif
eabd5d8d
AB		 21#if defined(CONFIG_AVR32)
22#include <asm/arch/portmux.h>
23#endif
f3100ff7 24#if defined(CONFIG_AT91FAMILY)
9d5028c2
WD		 25#include <asm/io.h>
26#include <asm/arch/hardware.h>
0cf0b931 27#include <asm/arch/at91_pio.h>
cb96a0a4 28#ifdef CONFIG_ATMEL_LEGACY
4e574c4e 29#include <asm/arch/gpio.h>
0cf0b931 30#endif
4e574c4e 31#endif
1b6275df 32#if defined(CONFIG_MPC852T) || defined(CONFIG_MPC866)
a21ca95f
HS		 33#include <asm/io.h>
34#endif
c609719b
WD		 35#include <i2c.h>
36
793b5726
MF		 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
c609719b
WD		 89/* #define DEBUG_I2C */
90
d87080b7 91DECLARE_GLOBAL_DATA_PTR;
ea818dbb
HS		 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
90f002a9
MV		 105#if !defined(CONFIG_SYS_I2C_SOFT_SPEED)
106#define CONFIG_SYS_I2C_SOFT_SPEED CONFIG_SYS_I2C_SPEED
ea818dbb 107#endif
90f002a9
MV		 108#if !defined(CONFIG_SYS_I2C_SOFT_SLAVE)
109#define CONFIG_SYS_I2C_SOFT_SLAVE CONFIG_SYS_I2C_SLAVE
d87080b7
WD		 110#endif
111
c609719b
WD		 112/*-----------------------------------------------------------------------
113 * Definitions
114 */
c609719b
WD		 115#define RETRIES 0
116
c609719b
WD		 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 { \
c609719b
WD		 123 printf (fmt ,##args); \
124 } while (0)
125#else
126#define PRINTD(fmt,args...)
127#endif
128
129/*-----------------------------------------------------------------------
130 * Local functions
131 */
6d0f6bcf 132#if !defined(CONFIG_SYS_I2C_INIT_BOARD)
c609719b 133static void send_reset (void);
4ca107ef 134#endif
c609719b
WD		 135static void send_start (void);
136static void send_stop (void);
137static void send_ack (int);
138static int write_byte (uchar byte);
139static uchar read_byte (int);
140
6d0f6bcf 141#if !defined(CONFIG_SYS_I2C_INIT_BOARD)
c609719b
WD		 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 */
147static void send_reset(void)
148{
98aed379 149 I2C_SOFT_DECLARATIONS /* intentional without ';' */
c609719b
WD		 150 int j;
151
60fbe254 152 I2C_SCL(1);
c609719b 153 I2C_SDA(1);
60fbe254
WD		 154#ifdef I2C_INIT
155 I2C_INIT;
156#endif
157 I2C_TRISTATE;
c609719b
WD		 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}
4ca107ef 169#endif
c609719b
WD		 170
171/*-----------------------------------------------------------------------
172 * START: High -> Low on SDA while SCL is High
173 */
174static void send_start(void)
175{
98aed379 176 I2C_SOFT_DECLARATIONS /* intentional without ';' */
c609719b
WD		 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 */
191static void send_stop(void)
192{
98aed379 193 I2C_SOFT_DECLARATIONS /* intentional without ';' */
c609719b
WD		 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
c609719b
WD		 207/*-----------------------------------------------------------------------
208 * ack should be I2C_ACK or I2C_NOACK
209 */
210static void send_ack(int ack)
211{
98aed379 212 I2C_SOFT_DECLARATIONS /* intentional without ';' */
c609719b 213
c609719b
WD		 214 I2C_SCL(0);
215 I2C_DELAY;
c609719b 216 I2C_ACTIVE;
c15f80ea 217 I2C_SDA(ack);
c609719b
WD		 218 I2C_DELAY;
219 I2C_SCL(1);
220 I2C_DELAY;
221 I2C_DELAY;
222 I2C_SCL(0);
223 I2C_DELAY;
224}
225
c609719b
WD		 226/*-----------------------------------------------------------------------
227 * Send 8 bits and look for an acknowledgement.
228 */
229static int write_byte(uchar data)
230{
98aed379 231 I2C_SOFT_DECLARATIONS /* intentional without ';' */
c609719b
WD		 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
c609719b
WD		 267/*-----------------------------------------------------------------------
268 * if ack == I2C_ACK, ACK the byte so can continue reading, else
269 * send I2C_NOACK to end the read.
270 */
271static uchar read_byte(int ack)
272{
98aed379 273 I2C_SOFT_DECLARATIONS /* intentional without ';' */
c609719b
WD		 274 int data;
275 int j;
276
277 /*
278 * Read 8 bits, MSB first.
279 */
280 I2C_TRISTATE;
110e006f 281 I2C_SDA(1);
c609719b
WD		 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
c609719b
WD		 297/*-----------------------------------------------------------------------
298 * Initialization
299 */
ea818dbb 300static void soft_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
c609719b 301{
6d0f6bcf 302#if defined(CONFIG_SYS_I2C_INIT_BOARD)
4ca107ef
HS		 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
c609719b 308 /*
8bde7f77
WD		 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.
c609719b
WD		 313 */
314 send_reset ();
4ca107ef 315#endif
c609719b
WD		 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 */
ea818dbb 323static int soft_i2c_probe(struct i2c_adapter *adap, uint8_t addr)
c609719b
WD		 324{
325 int rc;
326
82d716fd 327 /*
8e7b703a 328 * perform 1 byte write transaction with just address byte
82d716fd
WD		 329 * (fake write)
330 */
c609719b 331 send_start();
6aff3115 332 rc = write_byte ((addr << 1) | 0);
c609719b
WD		 333 send_stop();
334
335 return (rc ? 1 : 0);
336}
337
338/*-----------------------------------------------------------------------
339 * Read bytes
340 */
ea818dbb
HS		 341static int soft_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
342 int alen, uchar *buffer, int len)
c609719b
WD		 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
6d0f6bcf 348#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
c609719b
WD		 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 */
6d0f6bcf 360 chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
c609719b
WD		 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 }
2ac6985a
AD		 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();
c609719b 397 send_start();
2ac6985a 398#endif
c609719b
WD		 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 */
ea818dbb
HS		 416static int soft_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
417 int alen, uchar *buffer, int len)
c609719b
WD		 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}
ea818dbb
HS		 447
448/*
449 * Register soft i2c adapters
450 */
37b33254 451U_BOOT_I2C_ADAP_COMPLETE(soft00, soft_i2c_init, soft_i2c_probe,
ea818dbb
HS		 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)
37b33254 456U_BOOT_I2C_ADAP_COMPLETE(soft01, soft_i2c_init, soft_i2c_probe,
ea818dbb
HS		 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)
37b33254 463U_BOOT_I2C_ADAP_COMPLETE(soft02, soft_i2c_init, soft_i2c_probe,
ea818dbb
HS		 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)
37b33254 470U_BOOT_I2C_ADAP_COMPLETE(soft03, soft_i2c_init, soft_i2c_probe,
ea818dbb
HS		 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
7ed45d3d 476#if defined(I2C_SOFT_DECLARATIONS5)
37b33254 477U_BOOT_I2C_ADAP_COMPLETE(soft04, soft_i2c_init, soft_i2c_probe,
7ed45d3d
DE		 478 soft_i2c_read, soft_i2c_write, NULL,
479 CONFIG_SYS_I2C_SOFT_SPEED_5,
480 CONFIG_SYS_I2C_SOFT_SLAVE_5,
481 4)
482#endif
483#if defined(I2C_SOFT_DECLARATIONS6)
37b33254 484U_BOOT_I2C_ADAP_COMPLETE(soft05, soft_i2c_init, soft_i2c_probe,
7ed45d3d
DE		 485 soft_i2c_read, soft_i2c_write, NULL,
486 CONFIG_SYS_I2C_SOFT_SPEED_6,
487 CONFIG_SYS_I2C_SOFT_SLAVE_6,
488 5)
489#endif
490#if defined(I2C_SOFT_DECLARATIONS7)
37b33254 491U_BOOT_I2C_ADAP_COMPLETE(soft06, soft_i2c_init, soft_i2c_probe,
7ed45d3d
DE		 492 soft_i2c_read, soft_i2c_write, NULL,
493 CONFIG_SYS_I2C_SOFT_SPEED_7,
494 CONFIG_SYS_I2C_SOFT_SLAVE_7,
495 6)
496#endif
497#if defined(I2C_SOFT_DECLARATIONS8)
37b33254 498U_BOOT_I2C_ADAP_COMPLETE(soft07, soft_i2c_init, soft_i2c_probe,
7ed45d3d
DE		 499 soft_i2c_read, soft_i2c_write, NULL,
500 CONFIG_SYS_I2C_SOFT_SPEED_8,
501 CONFIG_SYS_I2C_SOFT_SLAVE_8,
502 7)
503#endif
5c3b6dc1 504#if defined(I2C_SOFT_DECLARATIONS9)
37b33254 505U_BOOT_I2C_ADAP_COMPLETE(soft08, soft_i2c_init, soft_i2c_probe,
5c3b6dc1
DE		 506 soft_i2c_read, soft_i2c_write, NULL,
507 CONFIG_SYS_I2C_SOFT_SPEED_9,
508 CONFIG_SYS_I2C_SOFT_SLAVE_9,
509 8)
510#endif
511#if defined(I2C_SOFT_DECLARATIONS10)
37b33254 512U_BOOT_I2C_ADAP_COMPLETE(soft09, soft_i2c_init, soft_i2c_probe,
5c3b6dc1
DE		 513 soft_i2c_read, soft_i2c_write, NULL,
514 CONFIG_SYS_I2C_SOFT_SPEED_10,
515 CONFIG_SYS_I2C_SOFT_SLAVE_10,
516 9)
517#endif
518#if defined(I2C_SOFT_DECLARATIONS11)
519U_BOOT_I2C_ADAP_COMPLETE(soft10, soft_i2c_init, soft_i2c_probe,
520 soft_i2c_read, soft_i2c_write, NULL,
521 CONFIG_SYS_I2C_SOFT_SPEED_11,
522 CONFIG_SYS_I2C_SOFT_SLAVE_11,
523 10)
524#endif
525#if defined(I2C_SOFT_DECLARATIONS12)
526U_BOOT_I2C_ADAP_COMPLETE(soft11, soft_i2c_init, soft_i2c_probe,
527 soft_i2c_read, soft_i2c_write, NULL,
528 CONFIG_SYS_I2C_SOFT_SPEED_12,
529 CONFIG_SYS_I2C_SOFT_SLAVE_12,
530 11)
531#endif
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