i2c: switch from AT91 legacy to ATMEL legacy
[karo-tx-uboot.git] / drivers / i2c / soft_i2c.c
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 #ifdef  CONFIG_IXP425                   /* only valid for IXP425 */
33 #include <asm/arch/ixp425.h>
34 #endif
35 #if defined(CONFIG_MPC852T) || defined(CONFIG_MPC866)
36 #include <asm/io.h>
37 #endif
38 #include <i2c.h>
39
40 #if defined(CONFIG_SOFT_I2C_GPIO_SCL)
41 # include <asm/gpio.h>
42
43 # ifndef I2C_GPIO_SYNC
44 #  define I2C_GPIO_SYNC
45 # endif
46
47 # ifndef I2C_INIT
48 #  define I2C_INIT \
49         do { \
50                 gpio_request(CONFIG_SOFT_I2C_GPIO_SCL, "soft_i2c"); \
51                 gpio_request(CONFIG_SOFT_I2C_GPIO_SDA, "soft_i2c"); \
52         } while (0)
53 # endif
54
55 # ifndef I2C_ACTIVE
56 #  define I2C_ACTIVE do { } while (0)
57 # endif
58
59 # ifndef I2C_TRISTATE
60 #  define I2C_TRISTATE do { } while (0)
61 # endif
62
63 # ifndef I2C_READ
64 #  define I2C_READ gpio_get_value(CONFIG_SOFT_I2C_GPIO_SDA)
65 # endif
66
67 # ifndef I2C_SDA
68 #  define I2C_SDA(bit) \
69         do { \
70                 if (bit) \
71                         gpio_direction_input(CONFIG_SOFT_I2C_GPIO_SDA); \
72                 else \
73                         gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SDA, 0); \
74                 I2C_GPIO_SYNC; \
75         } while (0)
76 # endif
77
78 # ifndef I2C_SCL
79 #  define I2C_SCL(bit) \
80         do { \
81                 gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SCL, bit); \
82                 I2C_GPIO_SYNC; \
83         } while (0)
84 # endif
85
86 # ifndef I2C_DELAY
87 #  define I2C_DELAY udelay(5)   /* 1/4 I2C clock duration */
88 # endif
89
90 #endif
91
92 /* #define      DEBUG_I2C       */
93
94 DECLARE_GLOBAL_DATA_PTR;
95
96 #ifndef I2C_SOFT_DECLARATIONS
97 # if defined(CONFIG_MPC8260)
98 #  define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = \
99                 ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
100 # elif defined(CONFIG_8xx)
101 #  define I2C_SOFT_DECLARATIONS volatile immap_t *immr = \
102                 (immap_t *)CONFIG_SYS_IMMR;
103 # else
104 #  define I2C_SOFT_DECLARATIONS
105 # endif
106 #endif
107
108 #if !defined(CONFIG_SYS_I2C_SOFT_SPEED)
109 #define CONFIG_SYS_I2C_SOFT_SPEED CONFIG_SYS_I2C_SPEED
110 #endif
111 #if !defined(CONFIG_SYS_I2C_SOFT_SLAVE)
112 #define CONFIG_SYS_I2C_SOFT_SLAVE CONFIG_SYS_I2C_SLAVE
113 #endif
114
115 /*-----------------------------------------------------------------------
116  * Definitions
117  */
118 #define RETRIES         0
119
120 #define I2C_ACK         0               /* PD_SDA level to ack a byte */
121 #define I2C_NOACK       1               /* PD_SDA level to noack a byte */
122
123
124 #ifdef DEBUG_I2C
125 #define PRINTD(fmt,args...)     do {    \
126                 printf (fmt ,##args);   \
127         } while (0)
128 #else
129 #define PRINTD(fmt,args...)
130 #endif
131
132 /*-----------------------------------------------------------------------
133  * Local functions
134  */
135 #if !defined(CONFIG_SYS_I2C_INIT_BOARD)
136 static void  send_reset (void);
137 #endif
138 static void  send_start (void);
139 static void  send_stop  (void);
140 static void  send_ack   (int);
141 static int   write_byte (uchar byte);
142 static uchar read_byte  (int);
143
144 #if !defined(CONFIG_SYS_I2C_INIT_BOARD)
145 /*-----------------------------------------------------------------------
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  */
150 static void send_reset(void)
151 {
152         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
153         int j;
154
155         I2C_SCL(1);
156         I2C_SDA(1);
157 #ifdef  I2C_INIT
158         I2C_INIT;
159 #endif
160         I2C_TRISTATE;
161         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 }
172 #endif
173
174 /*-----------------------------------------------------------------------
175  * START: High -> Low on SDA while SCL is High
176  */
177 static void send_start(void)
178 {
179         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
180
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  */
194 static void send_stop(void)
195 {
196         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
197
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
210 /*-----------------------------------------------------------------------
211  * ack should be I2C_ACK or I2C_NOACK
212  */
213 static void send_ack(int ack)
214 {
215         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
216
217         I2C_SCL(0);
218         I2C_DELAY;
219         I2C_ACTIVE;
220         I2C_SDA(ack);
221         I2C_DELAY;
222         I2C_SCL(1);
223         I2C_DELAY;
224         I2C_DELAY;
225         I2C_SCL(0);
226         I2C_DELAY;
227 }
228
229 /*-----------------------------------------------------------------------
230  * Send 8 bits and look for an acknowledgement.
231  */
232 static int write_byte(uchar data)
233 {
234         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
235         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
270 /*-----------------------------------------------------------------------
271  * if ack == I2C_ACK, ACK the byte so can continue reading, else
272  * send I2C_NOACK to end the read.
273  */
274 static uchar read_byte(int ack)
275 {
276         I2C_SOFT_DECLARATIONS   /* intentional without ';' */
277         int  data;
278         int  j;
279
280         /*
281          * Read 8 bits, MSB first.
282          */
283         I2C_TRISTATE;
284         I2C_SDA(1);
285         data = 0;
286         for(j = 0; j < 8; j++) {
287                 I2C_SCL(0);
288                 I2C_DELAY;
289                 I2C_SCL(1);
290                 I2C_DELAY;
291                 data <<= 1;
292                 data |= I2C_READ;
293                 I2C_DELAY;
294         }
295         send_ack(ack);
296
297         return(data);
298 }
299
300 /*-----------------------------------------------------------------------
301  * Initialization
302  */
303 static void soft_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
304 {
305 #if defined(CONFIG_SYS_I2C_INIT_BOARD)
306         /* call board specific i2c bus reset routine before accessing the   */
307         /* environment, which might be in a chip on that bus. For details   */
308         /* about this problem see doc/I2C_Edge_Conditions.                  */
309         i2c_init_board();
310 #else
311         /*
312          * WARNING: Do NOT save speed in a static variable: if the
313          * I2C routines are called before RAM is initialized (to read
314          * the DIMM SPD, for instance), RAM won't be usable and your
315          * system will crash.
316          */
317         send_reset ();
318 #endif
319 }
320
321 /*-----------------------------------------------------------------------
322  * Probe to see if a chip is present.  Also good for checking for the
323  * completion of EEPROM writes since the chip stops responding until
324  * the write completes (typically 10mSec).
325  */
326 static int soft_i2c_probe(struct i2c_adapter *adap, uint8_t addr)
327 {
328         int rc;
329
330         /*
331          * perform 1 byte write transaction with just address byte
332          * (fake write)
333          */
334         send_start();
335         rc = write_byte ((addr << 1) | 0);
336         send_stop();
337
338         return (rc ? 1 : 0);
339 }
340
341 /*-----------------------------------------------------------------------
342  * Read bytes
343  */
344 static int  soft_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
345                         int alen, uchar *buffer, int len)
346 {
347         int shift;
348         PRINTD("i2c_read: chip %02X addr %02X alen %d buffer %p len %d\n",
349                 chip, addr, alen, buffer, len);
350
351 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
352         /*
353          * EEPROM chips that implement "address overflow" are ones
354          * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
355          * address and the extra bits end up in the "chip address"
356          * bit slots. This makes a 24WC08 (1Kbyte) chip look like
357          * four 256 byte chips.
358          *
359          * Note that we consider the length of the address field to
360          * still be one byte because the extra address bits are
361          * hidden in the chip address.
362          */
363         chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
364
365         PRINTD("i2c_read: fix addr_overflow: chip %02X addr %02X\n",
366                 chip, addr);
367 #endif
368
369         /*
370          * Do the addressing portion of a write cycle to set the
371          * chip's address pointer.  If the address length is zero,
372          * don't do the normal write cycle to set the address pointer,
373          * there is no address pointer in this chip.
374          */
375         send_start();
376         if(alen > 0) {
377                 if(write_byte(chip << 1)) {     /* write cycle */
378                         send_stop();
379                         PRINTD("i2c_read, no chip responded %02X\n", chip);
380                         return(1);
381                 }
382                 shift = (alen-1) * 8;
383                 while(alen-- > 0) {
384                         if(write_byte(addr >> shift)) {
385                                 PRINTD("i2c_read, address not <ACK>ed\n");
386                                 return(1);
387                         }
388                         shift -= 8;
389                 }
390
391                 /* Some I2C chips need a stop/start sequence here,
392                  * other chips don't work with a full stop and need
393                  * only a start.  Default behaviour is to send the
394                  * stop/start sequence.
395                  */
396 #ifdef CONFIG_SOFT_I2C_READ_REPEATED_START
397                 send_start();
398 #else
399                 send_stop();
400                 send_start();
401 #endif
402         }
403         /*
404          * Send the chip address again, this time for a read cycle.
405          * Then read the data.  On the last byte, we do a NACK instead
406          * of an ACK(len == 0) to terminate the read.
407          */
408         write_byte((chip << 1) | 1);    /* read cycle */
409         while(len-- > 0) {
410                 *buffer++ = read_byte(len == 0);
411         }
412         send_stop();
413         return(0);
414 }
415
416 /*-----------------------------------------------------------------------
417  * Write bytes
418  */
419 static int  soft_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
420                         int alen, uchar *buffer, int len)
421 {
422         int shift, failures = 0;
423
424         PRINTD("i2c_write: chip %02X addr %02X alen %d buffer %p len %d\n",
425                 chip, addr, alen, buffer, len);
426
427         send_start();
428         if(write_byte(chip << 1)) {     /* write cycle */
429                 send_stop();
430                 PRINTD("i2c_write, no chip responded %02X\n", chip);
431                 return(1);
432         }
433         shift = (alen-1) * 8;
434         while(alen-- > 0) {
435                 if(write_byte(addr >> shift)) {
436                         PRINTD("i2c_write, address not <ACK>ed\n");
437                         return(1);
438                 }
439                 shift -= 8;
440         }
441
442         while(len-- > 0) {
443                 if(write_byte(*buffer++)) {
444                         failures++;
445                 }
446         }
447         send_stop();
448         return(failures);
449 }
450
451 /*
452  * Register soft i2c adapters
453  */
454 U_BOOT_I2C_ADAP_COMPLETE(soft0, soft_i2c_init, soft_i2c_probe,
455                          soft_i2c_read, soft_i2c_write, NULL,
456                          CONFIG_SYS_I2C_SOFT_SPEED, CONFIG_SYS_I2C_SOFT_SLAVE,
457                          0)
458 #if defined(I2C_SOFT_DECLARATIONS2)
459 U_BOOT_I2C_ADAP_COMPLETE(soft1, soft_i2c_init, soft_i2c_probe,
460                          soft_i2c_read, soft_i2c_write, NULL,
461                          CONFIG_SYS_I2C_SOFT_SPEED_2,
462                          CONFIG_SYS_I2C_SOFT_SLAVE_2,
463                          1)
464 #endif
465 #if defined(I2C_SOFT_DECLARATIONS3)
466 U_BOOT_I2C_ADAP_COMPLETE(soft2, soft_i2c_init, soft_i2c_probe,
467                          soft_i2c_read, soft_i2c_write, NULL,
468                          CONFIG_SYS_I2C_SOFT_SPEED_3,
469                          CONFIG_SYS_I2C_SOFT_SLAVE_3,
470                          2)
471 #endif
472 #if defined(I2C_SOFT_DECLARATIONS4)
473 U_BOOT_I2C_ADAP_COMPLETE(soft3, soft_i2c_init, soft_i2c_probe,
474                          soft_i2c_read, soft_i2c_write, NULL,
475                          CONFIG_SYS_I2C_SOFT_SPEED_4,
476                          CONFIG_SYS_I2C_SOFT_SLAVE_4,
477                          3)
478 #endif