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wdenkc6097192002-11-03 00:24:07 +00001/*
2 * (C) Copyright 2001, 2002
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 *
5 * See file CREDITS for list of people who contributed to this
6 * project.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21 * MA 02111-1307 USA
22 *
23 * This has been changed substantially by Gerald Van Baren, Custom IDEAS,
24 * vanbaren@cideas.com. It was heavily influenced by LiMon, written by
25 * Neil Russell.
26 */
27
28#include <common.h>
29#ifdef CONFIG_MPC8260 /* only valid for MPC8260 */
30#include <ioports.h>
Heiko Schochera21ca952008-10-17 13:52:51 +020031#include <asm/io.h>
wdenkc6097192002-11-03 00:24:07 +000032#endif
Ryan Mallonf3100ff2011-01-27 08:54:15 +130033#if defined(CONFIG_AT91FAMILY)
wdenk9d5028c2004-11-21 00:06:33 +000034#include <asm/io.h>
35#include <asm/arch/hardware.h>
Jens Scharsig0cf0b932010-02-03 22:46:58 +010036#include <asm/arch/at91_pio.h>
37#ifdef CONFIG_AT91_LEGACY
Daniel Gorsulowski4e574c42009-05-18 13:20:54 +020038#include <asm/arch/gpio.h>
Jens Scharsig0cf0b932010-02-03 22:46:58 +010039#endif
Daniel Gorsulowski4e574c42009-05-18 13:20:54 +020040#endif
Wolfgang Denkba94a1b2006-05-30 15:56:48 +020041#ifdef CONFIG_IXP425 /* only valid for IXP425 */
42#include <asm/arch/ixp425.h>
43#endif
Peter Pearseb0d8f5b2007-05-09 11:37:56 +010044#ifdef CONFIG_LPC2292
45#include <asm/arch/hardware.h>
46#endif
Heiko Schocher1b6275d2009-03-12 07:37:34 +010047#if defined(CONFIG_MPC852T) || defined(CONFIG_MPC866)
Heiko Schochera21ca952008-10-17 13:52:51 +020048#include <asm/io.h>
49#endif
wdenkc6097192002-11-03 00:24:07 +000050#include <i2c.h>
51
Mike Frysinger793b5722010-07-21 13:38:02 -040052#if defined(CONFIG_SOFT_I2C_GPIO_SCL)
53# include <asm/gpio.h>
54
55# ifndef I2C_GPIO_SYNC
56# define I2C_GPIO_SYNC
57# endif
58
59# ifndef I2C_INIT
60# define I2C_INIT \
61 do { \
62 gpio_request(CONFIG_SOFT_I2C_GPIO_SCL, "soft_i2c"); \
63 gpio_request(CONFIG_SOFT_I2C_GPIO_SDA, "soft_i2c"); \
64 } while (0)
65# endif
66
67# ifndef I2C_ACTIVE
68# define I2C_ACTIVE do { } while (0)
69# endif
70
71# ifndef I2C_TRISTATE
72# define I2C_TRISTATE do { } while (0)
73# endif
74
75# ifndef I2C_READ
76# define I2C_READ gpio_get_value(CONFIG_SOFT_I2C_GPIO_SDA)
77# endif
78
79# ifndef I2C_SDA
80# define I2C_SDA(bit) \
81 do { \
82 if (bit) \
83 gpio_direction_input(CONFIG_SOFT_I2C_GPIO_SDA); \
84 else \
85 gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SDA, 0); \
86 I2C_GPIO_SYNC; \
87 } while (0)
88# endif
89
90# ifndef I2C_SCL
91# define I2C_SCL(bit) \
92 do { \
93 gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SCL, bit); \
94 I2C_GPIO_SYNC; \
95 } while (0)
96# endif
97
98# ifndef I2C_DELAY
99# define I2C_DELAY udelay(5) /* 1/4 I2C clock duration */
100# endif
101
102#endif
103
wdenkc6097192002-11-03 00:24:07 +0000104/* #define DEBUG_I2C */
105
Wolfgang Denkd87080b2006-03-31 18:32:53 +0200106#ifdef DEBUG_I2C
107DECLARE_GLOBAL_DATA_PTR;
108#endif
109
wdenkc6097192002-11-03 00:24:07 +0000110/*-----------------------------------------------------------------------
111 * Definitions
112 */
113
114#define RETRIES 0
115
wdenkc6097192002-11-03 00:24:07 +0000116#define I2C_ACK 0 /* PD_SDA level to ack a byte */
117#define I2C_NOACK 1 /* PD_SDA level to noack a byte */
118
119
120#ifdef DEBUG_I2C
121#define PRINTD(fmt,args...) do { \
wdenkc6097192002-11-03 00:24:07 +0000122 printf (fmt ,##args); \
123 } while (0)
124#else
125#define PRINTD(fmt,args...)
126#endif
127
Heiko Schocher799b7842008-10-15 09:34:45 +0200128#if defined(CONFIG_I2C_MULTI_BUS)
Trent Piepho5e3ab682008-11-12 17:29:48 -0800129static unsigned int i2c_bus_num __attribute__ ((section (".data"))) = 0;
Heiko Schocher799b7842008-10-15 09:34:45 +0200130#endif /* CONFIG_I2C_MULTI_BUS */
131
wdenkc6097192002-11-03 00:24:07 +0000132/*-----------------------------------------------------------------------
133 * Local functions
134 */
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200135#if !defined(CONFIG_SYS_I2C_INIT_BOARD)
wdenkc6097192002-11-03 00:24:07 +0000136static void send_reset (void);
Heiko Schocher4ca107e2008-10-15 09:38:38 +0200137#endif
wdenkc6097192002-11-03 00:24:07 +0000138static void send_start (void);
139static void send_stop (void);
140static void send_ack (int);
141static int write_byte (uchar byte);
142static uchar read_byte (int);
143
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200144#if !defined(CONFIG_SYS_I2C_INIT_BOARD)
wdenkc6097192002-11-03 00:24:07 +0000145/*-----------------------------------------------------------------------
146 * Send a reset sequence consisting of 9 clocks with the data signal high
147 * to clock any confused device back into an idle state. Also send a
148 * <stop> at the end of the sequence for belts & suspenders.
149 */
150static void send_reset(void)
151{
Heiko Schocher98aed372008-10-15 09:35:26 +0200152 I2C_SOFT_DECLARATIONS /* intentional without ';' */
wdenkc6097192002-11-03 00:24:07 +0000153 int j;
154
wdenk60fbe252003-04-08 23:25:21 +0000155 I2C_SCL(1);
wdenkc6097192002-11-03 00:24:07 +0000156 I2C_SDA(1);
wdenk60fbe252003-04-08 23:25:21 +0000157#ifdef I2C_INIT
158 I2C_INIT;
159#endif
160 I2C_TRISTATE;
wdenkc6097192002-11-03 00:24:07 +0000161 for(j = 0; j < 9; j++) {
162 I2C_SCL(0);
163 I2C_DELAY;
164 I2C_DELAY;
165 I2C_SCL(1);
166 I2C_DELAY;
167 I2C_DELAY;
168 }
169 send_stop();
170 I2C_TRISTATE;
171}
Heiko Schocher4ca107e2008-10-15 09:38:38 +0200172#endif
wdenkc6097192002-11-03 00:24:07 +0000173
174/*-----------------------------------------------------------------------
175 * START: High -> Low on SDA while SCL is High
176 */
177static void send_start(void)
178{
Heiko Schocher98aed372008-10-15 09:35:26 +0200179 I2C_SOFT_DECLARATIONS /* intentional without ';' */
wdenkc6097192002-11-03 00:24:07 +0000180
181 I2C_DELAY;
182 I2C_SDA(1);
183 I2C_ACTIVE;
184 I2C_DELAY;
185 I2C_SCL(1);
186 I2C_DELAY;
187 I2C_SDA(0);
188 I2C_DELAY;
189}
190
191/*-----------------------------------------------------------------------
192 * STOP: Low -> High on SDA while SCL is High
193 */
194static void send_stop(void)
195{
Heiko Schocher98aed372008-10-15 09:35:26 +0200196 I2C_SOFT_DECLARATIONS /* intentional without ';' */
wdenkc6097192002-11-03 00:24:07 +0000197
198 I2C_SCL(0);
199 I2C_DELAY;
200 I2C_SDA(0);
201 I2C_ACTIVE;
202 I2C_DELAY;
203 I2C_SCL(1);
204 I2C_DELAY;
205 I2C_SDA(1);
206 I2C_DELAY;
207 I2C_TRISTATE;
208}
209
wdenkc6097192002-11-03 00:24:07 +0000210/*-----------------------------------------------------------------------
211 * ack should be I2C_ACK or I2C_NOACK
212 */
213static void send_ack(int ack)
214{
Heiko Schocher98aed372008-10-15 09:35:26 +0200215 I2C_SOFT_DECLARATIONS /* intentional without ';' */
wdenkc6097192002-11-03 00:24:07 +0000216
wdenkc6097192002-11-03 00:24:07 +0000217 I2C_SCL(0);
218 I2C_DELAY;
wdenkc6097192002-11-03 00:24:07 +0000219 I2C_ACTIVE;
Wolfgang Denkc15f80e2006-03-13 00:50:48 +0100220 I2C_SDA(ack);
wdenkc6097192002-11-03 00:24:07 +0000221 I2C_DELAY;
222 I2C_SCL(1);
223 I2C_DELAY;
224 I2C_DELAY;
225 I2C_SCL(0);
226 I2C_DELAY;
227}
228
wdenkc6097192002-11-03 00:24:07 +0000229/*-----------------------------------------------------------------------
230 * Send 8 bits and look for an acknowledgement.
231 */
232static int write_byte(uchar data)
233{
Heiko Schocher98aed372008-10-15 09:35:26 +0200234 I2C_SOFT_DECLARATIONS /* intentional without ';' */
wdenkc6097192002-11-03 00:24:07 +0000235 int j;
236 int nack;
237
238 I2C_ACTIVE;
239 for(j = 0; j < 8; j++) {
240 I2C_SCL(0);
241 I2C_DELAY;
242 I2C_SDA(data & 0x80);
243 I2C_DELAY;
244 I2C_SCL(1);
245 I2C_DELAY;
246 I2C_DELAY;
247
248 data <<= 1;
249 }
250
251 /*
252 * Look for an <ACK>(negative logic) and return it.
253 */
254 I2C_SCL(0);
255 I2C_DELAY;
256 I2C_SDA(1);
257 I2C_TRISTATE;
258 I2C_DELAY;
259 I2C_SCL(1);
260 I2C_DELAY;
261 I2C_DELAY;
262 nack = I2C_READ;
263 I2C_SCL(0);
264 I2C_DELAY;
265 I2C_ACTIVE;
266
267 return(nack); /* not a nack is an ack */
268}
269
Heiko Schocher799b7842008-10-15 09:34:45 +0200270#if defined(CONFIG_I2C_MULTI_BUS)
271/*
272 * Functions for multiple I2C bus handling
273 */
274unsigned int i2c_get_bus_num(void)
275{
276 return i2c_bus_num;
277}
278
279int i2c_set_bus_num(unsigned int bus)
280{
Heiko Schocher67b23a32008-10-15 09:39:47 +0200281#if defined(CONFIG_I2C_MUX)
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200282 if (bus < CONFIG_SYS_MAX_I2C_BUS) {
Heiko Schocher67b23a32008-10-15 09:39:47 +0200283 i2c_bus_num = bus;
284 } else {
285 int ret;
286
287 ret = i2x_mux_select_mux(bus);
Heiko Schocher4bd55662011-04-08 16:24:09 +0200288 i2c_init_board();
Heiko Schocher67b23a32008-10-15 09:39:47 +0200289 if (ret == 0)
290 i2c_bus_num = bus;
291 else
292 return ret;
293 }
294#else
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200295 if (bus >= CONFIG_SYS_MAX_I2C_BUS)
Heiko Schocher799b7842008-10-15 09:34:45 +0200296 return -1;
297 i2c_bus_num = bus;
Heiko Schocher67b23a32008-10-15 09:39:47 +0200298#endif
Heiko Schocher799b7842008-10-15 09:34:45 +0200299 return 0;
300}
Jens Scharsigd144f942009-03-31 08:18:29 +0200301#endif
Heiko Schocher799b7842008-10-15 09:34:45 +0200302
wdenkc6097192002-11-03 00:24:07 +0000303/*-----------------------------------------------------------------------
304 * if ack == I2C_ACK, ACK the byte so can continue reading, else
305 * send I2C_NOACK to end the read.
306 */
307static uchar read_byte(int ack)
308{
Heiko Schocher98aed372008-10-15 09:35:26 +0200309 I2C_SOFT_DECLARATIONS /* intentional without ';' */
wdenkc6097192002-11-03 00:24:07 +0000310 int data;
311 int j;
312
313 /*
314 * Read 8 bits, MSB first.
315 */
316 I2C_TRISTATE;
Haavard Skinnemoen110e0062008-05-16 11:08:11 +0200317 I2C_SDA(1);
wdenkc6097192002-11-03 00:24:07 +0000318 data = 0;
319 for(j = 0; j < 8; j++) {
320 I2C_SCL(0);
321 I2C_DELAY;
322 I2C_SCL(1);
323 I2C_DELAY;
324 data <<= 1;
325 data |= I2C_READ;
326 I2C_DELAY;
327 }
328 send_ack(ack);
329
330 return(data);
331}
332
333/*=====================================================================*/
334/* Public Functions */
335/*=====================================================================*/
336
337/*-----------------------------------------------------------------------
338 * Initialization
339 */
340void i2c_init (int speed, int slaveaddr)
341{
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200342#if defined(CONFIG_SYS_I2C_INIT_BOARD)
Heiko Schocher4ca107e2008-10-15 09:38:38 +0200343 /* call board specific i2c bus reset routine before accessing the */
344 /* environment, which might be in a chip on that bus. For details */
345 /* about this problem see doc/I2C_Edge_Conditions. */
346 i2c_init_board();
347#else
wdenkc6097192002-11-03 00:24:07 +0000348 /*
wdenk8bde7f72003-06-27 21:31:46 +0000349 * WARNING: Do NOT save speed in a static variable: if the
350 * I2C routines are called before RAM is initialized (to read
351 * the DIMM SPD, for instance), RAM won't be usable and your
352 * system will crash.
wdenkc6097192002-11-03 00:24:07 +0000353 */
354 send_reset ();
Heiko Schocher4ca107e2008-10-15 09:38:38 +0200355#endif
wdenkc6097192002-11-03 00:24:07 +0000356}
357
358/*-----------------------------------------------------------------------
359 * Probe to see if a chip is present. Also good for checking for the
360 * completion of EEPROM writes since the chip stops responding until
361 * the write completes (typically 10mSec).
362 */
363int i2c_probe(uchar addr)
364{
365 int rc;
366
Wolfgang Denk82d716f2006-03-12 01:30:45 +0100367 /*
Wolfgang Denk8e7b7032006-03-12 02:55:22 +0100368 * perform 1 byte write transaction with just address byte
Wolfgang Denk82d716f2006-03-12 01:30:45 +0100369 * (fake write)
370 */
wdenkc6097192002-11-03 00:24:07 +0000371 send_start();
wdenk6aff3112002-12-17 01:51:00 +0000372 rc = write_byte ((addr << 1) | 0);
wdenkc6097192002-11-03 00:24:07 +0000373 send_stop();
374
375 return (rc ? 1 : 0);
376}
377
378/*-----------------------------------------------------------------------
379 * Read bytes
380 */
381int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
382{
383 int shift;
384 PRINTD("i2c_read: chip %02X addr %02X alen %d buffer %p len %d\n",
385 chip, addr, alen, buffer, len);
386
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200387#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
wdenkc6097192002-11-03 00:24:07 +0000388 /*
389 * EEPROM chips that implement "address overflow" are ones
390 * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
391 * address and the extra bits end up in the "chip address"
392 * bit slots. This makes a 24WC08 (1Kbyte) chip look like
393 * four 256 byte chips.
394 *
395 * Note that we consider the length of the address field to
396 * still be one byte because the extra address bits are
397 * hidden in the chip address.
398 */
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200399 chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
wdenkc6097192002-11-03 00:24:07 +0000400
401 PRINTD("i2c_read: fix addr_overflow: chip %02X addr %02X\n",
402 chip, addr);
403#endif
404
405 /*
406 * Do the addressing portion of a write cycle to set the
407 * chip's address pointer. If the address length is zero,
408 * don't do the normal write cycle to set the address pointer,
409 * there is no address pointer in this chip.
410 */
411 send_start();
412 if(alen > 0) {
413 if(write_byte(chip << 1)) { /* write cycle */
414 send_stop();
415 PRINTD("i2c_read, no chip responded %02X\n", chip);
416 return(1);
417 }
418 shift = (alen-1) * 8;
419 while(alen-- > 0) {
420 if(write_byte(addr >> shift)) {
421 PRINTD("i2c_read, address not <ACK>ed\n");
422 return(1);
423 }
424 shift -= 8;
425 }
Andrew Dyer2ac69852008-12-29 17:36:01 -0600426
427 /* Some I2C chips need a stop/start sequence here,
428 * other chips don't work with a full stop and need
429 * only a start. Default behaviour is to send the
430 * stop/start sequence.
431 */
432#ifdef CONFIG_SOFT_I2C_READ_REPEATED_START
wdenkc6097192002-11-03 00:24:07 +0000433 send_start();
Andrew Dyer2ac69852008-12-29 17:36:01 -0600434#else
435 send_stop();
436 send_start();
437#endif
wdenkc6097192002-11-03 00:24:07 +0000438 }
439 /*
440 * Send the chip address again, this time for a read cycle.
441 * Then read the data. On the last byte, we do a NACK instead
442 * of an ACK(len == 0) to terminate the read.
443 */
444 write_byte((chip << 1) | 1); /* read cycle */
445 while(len-- > 0) {
446 *buffer++ = read_byte(len == 0);
447 }
448 send_stop();
449 return(0);
450}
451
452/*-----------------------------------------------------------------------
453 * Write bytes
454 */
455int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
456{
457 int shift, failures = 0;
458
459 PRINTD("i2c_write: chip %02X addr %02X alen %d buffer %p len %d\n",
460 chip, addr, alen, buffer, len);
461
462 send_start();
463 if(write_byte(chip << 1)) { /* write cycle */
464 send_stop();
465 PRINTD("i2c_write, no chip responded %02X\n", chip);
466 return(1);
467 }
468 shift = (alen-1) * 8;
469 while(alen-- > 0) {
470 if(write_byte(addr >> shift)) {
471 PRINTD("i2c_write, address not <ACK>ed\n");
472 return(1);
473 }
474 shift -= 8;
475 }
476
477 while(len-- > 0) {
478 if(write_byte(*buffer++)) {
479 failures++;
480 }
481 }
482 send_stop();
483 return(failures);
484}