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wdenk1cb8e982003-03-06 21:55:29 +00001/*
2 * (C) Copyright 2002
3 * David Mueller, ELSOFT AG, d.mueller@elsoft.ch
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
24/* This code should work for both the S3C2400 and the S3C2410
25 * as they seem to have the same I2C controller inside.
26 * The different address mapping is handled by the s3c24xx.h files below.
27 */
28
29#include <common.h>
30
31#ifdef CONFIG_DRIVER_S3C24X0_I2C
32
33#if defined(CONFIG_S3C2400)
34#include <s3c2400.h>
35#elif defined(CONFIG_S3C2410)
36#include <s3c2410.h>
37#endif
38#include <i2c.h>
39
40#ifdef CONFIG_HARD_I2C
41
wdenk48b42612003-06-19 23:01:32 +000042#define I2C_WRITE 0
43#define I2C_READ 1
wdenk1cb8e982003-03-06 21:55:29 +000044
wdenk48b42612003-06-19 23:01:32 +000045#define I2C_OK 0
46#define I2C_NOK 1
47#define I2C_NACK 2
48#define I2C_NOK_LA 3 /* Lost arbitration */
49#define I2C_NOK_TOUT 4 /* time out */
wdenk1cb8e982003-03-06 21:55:29 +000050
wdenk48b42612003-06-19 23:01:32 +000051#define I2CSTAT_BSY 0x20 /* Busy bit */
52#define I2CSTAT_NACK 0x01 /* Nack bit */
53#define I2CCON_IRPND 0x10 /* Interrupt pending bit */
54#define I2C_MODE_MT 0xC0 /* Master Transmit Mode */
55#define I2C_MODE_MR 0x80 /* Master Receive Mode */
56#define I2C_START_STOP 0x20 /* START / STOP */
57#define I2C_TXRX_ENA 0x10 /* I2C Tx/Rx enable */
wdenk1cb8e982003-03-06 21:55:29 +000058
wdenkb56ddc62003-09-15 21:14:37 +000059#define I2C_TIMEOUT 1 /* 1 second */
wdenk1cb8e982003-03-06 21:55:29 +000060
61
wdenk48b42612003-06-19 23:01:32 +000062static int GetI2CSDA(void)
wdenk1cb8e982003-03-06 21:55:29 +000063{
wdenk48b42612003-06-19 23:01:32 +000064 S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();
65
wdenk6dff5522003-07-15 07:45:49 +000066#ifdef CONFIG_S3C2410
wdenk48b42612003-06-19 23:01:32 +000067 return (gpio->GPEDAT & 0x8000) >> 15;
wdenk6dff5522003-07-15 07:45:49 +000068#endif
69#ifdef CONFIG_S3C2400
70 return (gpio->PGDAT & 0x0020) >> 5;
71#endif
wdenk1cb8e982003-03-06 21:55:29 +000072}
73
wdenk06d01db2003-03-14 20:47:52 +000074#if 0
wdenk48b42612003-06-19 23:01:32 +000075static void SetI2CSDA(int x)
wdenk1cb8e982003-03-06 21:55:29 +000076{
77 rGPEDAT = (rGPEDAT & ~0x8000) | (x&1) << 15;
78}
wdenk06d01db2003-03-14 20:47:52 +000079#endif
wdenk1cb8e982003-03-06 21:55:29 +000080
wdenk48b42612003-06-19 23:01:32 +000081static void SetI2CSCL(int x)
wdenk1cb8e982003-03-06 21:55:29 +000082{
wdenk48b42612003-06-19 23:01:32 +000083 S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();
84
wdenk6dff5522003-07-15 07:45:49 +000085#ifdef CONFIG_S3C2410
wdenk48b42612003-06-19 23:01:32 +000086 gpio->GPEDAT = (gpio->GPEDAT & ~0x4000) | (x&1) << 14;
wdenk6dff5522003-07-15 07:45:49 +000087#endif
88#ifdef CONFIG_S3C2400
89 gpio->PGDAT = (gpio->PGDAT & ~0x0040) | (x&1) << 6;
90#endif
wdenk1cb8e982003-03-06 21:55:29 +000091}
92
93
wdenkfc3e2162003-10-08 22:33:00 +000094static int WaitForXfer (void)
wdenk1cb8e982003-03-06 21:55:29 +000095{
wdenkfc3e2162003-10-08 22:33:00 +000096 S3C24X0_I2C *const i2c = S3C24X0_GetBase_I2C ();
97 int i, status;
wdenk1cb8e982003-03-06 21:55:29 +000098
wdenkfc3e2162003-10-08 22:33:00 +000099 i = I2C_TIMEOUT * 10000;
wdenk48b42612003-06-19 23:01:32 +0000100 status = i2c->IICCON;
wdenkfc3e2162003-10-08 22:33:00 +0000101 while ((i > 0) && !(status & I2CCON_IRPND)) {
102 udelay (100);
103 status = i2c->IICCON;
104 i--;
105 }
wdenk1cb8e982003-03-06 21:55:29 +0000106
wdenkfc3e2162003-10-08 22:33:00 +0000107 return (status & I2CCON_IRPND) ? I2C_OK : I2C_NOK_TOUT;
wdenk1cb8e982003-03-06 21:55:29 +0000108}
109
wdenkfc3e2162003-10-08 22:33:00 +0000110static int IsACK (void)
wdenk1cb8e982003-03-06 21:55:29 +0000111{
wdenkfc3e2162003-10-08 22:33:00 +0000112 S3C24X0_I2C *const i2c = S3C24X0_GetBase_I2C ();
wdenk48b42612003-06-19 23:01:32 +0000113
wdenkfc3e2162003-10-08 22:33:00 +0000114 return (!(i2c->IICSTAT & I2CSTAT_NACK));
wdenk1cb8e982003-03-06 21:55:29 +0000115}
116
wdenkfc3e2162003-10-08 22:33:00 +0000117static void ReadWriteByte (void)
wdenk1cb8e982003-03-06 21:55:29 +0000118{
wdenkfc3e2162003-10-08 22:33:00 +0000119 S3C24X0_I2C *const i2c = S3C24X0_GetBase_I2C ();
wdenk48b42612003-06-19 23:01:32 +0000120
wdenkfc3e2162003-10-08 22:33:00 +0000121 i2c->IICCON &= ~I2CCON_IRPND;
wdenk1cb8e982003-03-06 21:55:29 +0000122}
123
124void i2c_init (int speed, int slaveadd)
125{
wdenkfc3e2162003-10-08 22:33:00 +0000126 S3C24X0_I2C *const i2c = S3C24X0_GetBase_I2C ();
127 S3C24X0_GPIO *const gpio = S3C24X0_GetBase_GPIO ();
128 ulong freq, pres = 16, div;
129 int i, status;
wdenk1cb8e982003-03-06 21:55:29 +0000130
wdenkfc3e2162003-10-08 22:33:00 +0000131 /* wait for some time to give previous transfer a chance to finish */
wdenk1cb8e982003-03-06 21:55:29 +0000132
wdenkfc3e2162003-10-08 22:33:00 +0000133 i = I2C_TIMEOUT * 1000;
wdenk48b42612003-06-19 23:01:32 +0000134 status = i2c->IICSTAT;
wdenkfc3e2162003-10-08 22:33:00 +0000135 while ((i > 0) && (status & I2CSTAT_BSY)) {
136 udelay (1000);
137 status = i2c->IICSTAT;
wdenk1cb8e982003-03-06 21:55:29 +0000138 i--;
139 }
wdenk1cb8e982003-03-06 21:55:29 +0000140
wdenkfc3e2162003-10-08 22:33:00 +0000141 if ((status & I2CSTAT_BSY) || GetI2CSDA () == 0) {
wdenk6dff5522003-07-15 07:45:49 +0000142#ifdef CONFIG_S3C2410
wdenkfc3e2162003-10-08 22:33:00 +0000143 ulong old_gpecon = gpio->GPECON;
wdenk6dff5522003-07-15 07:45:49 +0000144#endif
145#ifdef CONFIG_S3C2400
wdenkfc3e2162003-10-08 22:33:00 +0000146 ulong old_gpecon = gpio->PGCON;
wdenk6dff5522003-07-15 07:45:49 +0000147#endif
wdenkfc3e2162003-10-08 22:33:00 +0000148 /* bus still busy probably by (most) previously interrupted transfer */
wdenk1cb8e982003-03-06 21:55:29 +0000149
wdenkfc3e2162003-10-08 22:33:00 +0000150#ifdef CONFIG_S3C2410
151 /* set I2CSDA and I2CSCL (GPE15, GPE14) to GPIO */
152 gpio->GPECON = (gpio->GPECON & ~0xF0000000) | 0x10000000;
153#endif
154#ifdef CONFIG_S3C2400
155 /* set I2CSDA and I2CSCL (PG5, PG6) to GPIO */
156 gpio->PGCON = (gpio->PGCON & ~0x00003c00) | 0x00000c00;
157#endif
wdenk1cb8e982003-03-06 21:55:29 +0000158
wdenkfc3e2162003-10-08 22:33:00 +0000159 /* toggle I2CSCL until bus idle */
160 SetI2CSCL (0);
161 udelay (1000);
162 i = 10;
163 while ((i > 0) && (GetI2CSDA () != 1)) {
164 SetI2CSCL (1);
165 udelay (1000);
166 SetI2CSCL (0);
167 udelay (1000);
168 i--;
169 }
170 SetI2CSCL (1);
171 udelay (1000);
wdenk1cb8e982003-03-06 21:55:29 +0000172
wdenkfc3e2162003-10-08 22:33:00 +0000173 /* restore pin functions */
174#ifdef CONFIG_S3C2410
175 gpio->GPECON = old_gpecon;
176#endif
177#ifdef CONFIG_S3C2400
178 gpio->PGCON = old_gpecon;
179#endif
180 }
wdenk1cb8e982003-03-06 21:55:29 +0000181
wdenkfc3e2162003-10-08 22:33:00 +0000182 /* calculate prescaler and divisor values */
183 freq = get_PCLK ();
184 if ((freq / pres / (16 + 1)) > speed)
185 /* set prescaler to 512 */
186 pres = 512;
187
188 div = 0;
189 while ((freq / pres / (div + 1)) > speed)
190 div++;
191
192 /* set prescaler, divisor according to freq, also set
193 * ACKGEN, IRQ */
194 i2c->IICCON = (div & 0x0F) | 0xA0 | ((pres == 512) ? 0x40 : 0);
195
196 /* init to SLAVE REVEIVE and set slaveaddr */
197 i2c->IICSTAT = 0;
198 i2c->IICADD = slaveadd;
199 /* program Master Transmit (and implicit STOP) */
200 i2c->IICSTAT = I2C_MODE_MT | I2C_TXRX_ENA;
wdenk1cb8e982003-03-06 21:55:29 +0000201
202}
203
204/*
wdenkfc3e2162003-10-08 22:33:00 +0000205 * cmd_type is 0 for write, 1 for read.
206 *
207 * addr_len can take any value from 0-255, it is only limited
208 * by the char, we could make it larger if needed. If it is
209 * 0 we skip the address write cycle.
210 */
wdenk1cb8e982003-03-06 21:55:29 +0000211static
wdenkfc3e2162003-10-08 22:33:00 +0000212int i2c_transfer (unsigned char cmd_type,
213 unsigned char chip,
214 unsigned char addr[],
215 unsigned char addr_len,
216 unsigned char data[], unsigned short data_len)
wdenk1cb8e982003-03-06 21:55:29 +0000217{
wdenkfc3e2162003-10-08 22:33:00 +0000218 S3C24X0_I2C *const i2c = S3C24X0_GetBase_I2C ();
219 int i, status, result;
wdenk1cb8e982003-03-06 21:55:29 +0000220
wdenkfc3e2162003-10-08 22:33:00 +0000221 if (data == 0 || data_len == 0) {
222 /*Don't support data transfer of no length or to address 0 */
223 printf ("i2c_transfer: bad call\n");
224 return I2C_NOK;
225 }
wdenk1cb8e982003-03-06 21:55:29 +0000226
wdenkfc3e2162003-10-08 22:33:00 +0000227 /* Check I2C bus idle */
228 i = I2C_TIMEOUT * 1000;
wdenk48b42612003-06-19 23:01:32 +0000229 status = i2c->IICSTAT;
wdenkfc3e2162003-10-08 22:33:00 +0000230 while ((i > 0) && (status & I2CSTAT_BSY)) {
231 udelay (1000);
232 status = i2c->IICSTAT;
233 i--;
234 }
wdenk1cb8e982003-03-06 21:55:29 +0000235
wdenkfc3e2162003-10-08 22:33:00 +0000236 if (status & I2CSTAT_BSY)
237 return I2C_NOK_TOUT;
wdenk1cb8e982003-03-06 21:55:29 +0000238
wdenkfc3e2162003-10-08 22:33:00 +0000239 i2c->IICCON |= 0x80;
240 result = I2C_OK;
wdenk1cb8e982003-03-06 21:55:29 +0000241
wdenkfc3e2162003-10-08 22:33:00 +0000242 switch (cmd_type) {
wdenk48b42612003-06-19 23:01:32 +0000243 case I2C_WRITE:
wdenkfc3e2162003-10-08 22:33:00 +0000244 if (addr && addr_len) {
245 i2c->IICDS = chip;
246 /* send START */
247 i2c->IICSTAT = I2C_MODE_MT | I2C_TXRX_ENA | I2C_START_STOP;
248 i = 0;
249 while ((i < addr_len) && (result == I2C_OK)) {
250 result = WaitForXfer ();
251 i2c->IICDS = addr[i];
252 ReadWriteByte ();
253 i++;
254 }
255 i = 0;
256 while ((i < data_len) && (result == I2C_OK)) {
257 result = WaitForXfer ();
258 i2c->IICDS = data[i];
259 ReadWriteByte ();
260 i++;
261 }
262 } else {
263 i2c->IICDS = chip;
264 /* send START */
265 i2c->IICSTAT = I2C_MODE_MT | I2C_TXRX_ENA | I2C_START_STOP;
266 i = 0;
267 while ((i < data_len) && (result = I2C_OK)) {
268 result = WaitForXfer ();
269 i2c->IICDS = data[i];
270 ReadWriteByte ();
271 i++;
272 }
wdenk1cb8e982003-03-06 21:55:29 +0000273 }
wdenk1cb8e982003-03-06 21:55:29 +0000274
wdenkfc3e2162003-10-08 22:33:00 +0000275 if (result == I2C_OK)
276 result = WaitForXfer ();
wdenk1cb8e982003-03-06 21:55:29 +0000277
wdenkfc3e2162003-10-08 22:33:00 +0000278 /* send STOP */
279 i2c->IICSTAT = I2C_MODE_MR | I2C_TXRX_ENA;
280 ReadWriteByte ();
281 break;
wdenk1cb8e982003-03-06 21:55:29 +0000282
wdenk48b42612003-06-19 23:01:32 +0000283 case I2C_READ:
wdenkfc3e2162003-10-08 22:33:00 +0000284 if (addr && addr_len) {
285 i2c->IICSTAT = I2C_MODE_MT | I2C_TXRX_ENA;
286 i2c->IICDS = chip;
287 /* send START */
288 i2c->IICSTAT |= I2C_START_STOP;
289 result = WaitForXfer ();
290 if (IsACK ()) {
291 i = 0;
292 while ((i < addr_len) && (result == I2C_OK)) {
293 i2c->IICDS = addr[i];
294 ReadWriteByte ();
295 result = WaitForXfer ();
296 i++;
297 }
wdenk1cb8e982003-03-06 21:55:29 +0000298
wdenkfc3e2162003-10-08 22:33:00 +0000299 i2c->IICDS = chip;
300 /* resend START */
301 i2c->IICSTAT = I2C_MODE_MR | I2C_TXRX_ENA |
302 I2C_START_STOP;
303 ReadWriteByte ();
304 result = WaitForXfer ();
305 i = 0;
306 while ((i < data_len) && (result == I2C_OK)) {
307 /* disable ACK for final READ */
308 if (i == data_len - 1)
309 i2c->IICCON &= ~0x80;
310 ReadWriteByte ();
311 result = WaitForXfer ();
312 data[i] = i2c->IICDS;
313 i++;
314 }
315 } else {
316 result = I2C_NACK;
317 }
318
wdenk1cb8e982003-03-06 21:55:29 +0000319 } else {
wdenkfc3e2162003-10-08 22:33:00 +0000320 i2c->IICSTAT = I2C_MODE_MR | I2C_TXRX_ENA;
321 i2c->IICDS = chip;
322 /* send START */
323 i2c->IICSTAT |= I2C_START_STOP;
324 result = WaitForXfer ();
325
326 if (IsACK ()) {
327 i = 0;
328 while ((i < data_len) && (result == I2C_OK)) {
329 /* disable ACK for final READ */
330 if (i == data_len - 1)
331 i2c->IICCON &= ~0x80;
332 ReadWriteByte ();
333 result = WaitForXfer ();
334 data[i] = i2c->IICDS;
335 i++;
336 }
337 } else {
338 result = I2C_NACK;
339 }
wdenk1cb8e982003-03-06 21:55:29 +0000340 }
341
wdenkfc3e2162003-10-08 22:33:00 +0000342 /* send STOP */
wdenk48b42612003-06-19 23:01:32 +0000343 i2c->IICSTAT = I2C_MODE_MR | I2C_TXRX_ENA;
wdenkfc3e2162003-10-08 22:33:00 +0000344 ReadWriteByte ();
345 break;
wdenk1cb8e982003-03-06 21:55:29 +0000346
347 default:
wdenkfc3e2162003-10-08 22:33:00 +0000348 printf ("i2c_transfer: bad call\n");
349 result = I2C_NOK;
350 break;
351 }
wdenk1cb8e982003-03-06 21:55:29 +0000352
wdenkfc3e2162003-10-08 22:33:00 +0000353 return (result);
wdenk1cb8e982003-03-06 21:55:29 +0000354}
355
356int i2c_probe (uchar chip)
357{
wdenkfc3e2162003-10-08 22:33:00 +0000358 uchar buf[1];
wdenk1cb8e982003-03-06 21:55:29 +0000359
wdenkfc3e2162003-10-08 22:33:00 +0000360 buf[0] = 0;
wdenk1cb8e982003-03-06 21:55:29 +0000361
wdenkfc3e2162003-10-08 22:33:00 +0000362 /*
363 * What is needed is to send the chip address and verify that the
364 * address was <ACK>ed (i.e. there was a chip at that address which
365 * drove the data line low).
366 */
367 return (i2c_transfer (I2C_READ, chip << 1, 0, 0, buf, 1) != I2C_OK);
wdenk1cb8e982003-03-06 21:55:29 +0000368}
369
370int i2c_read (uchar chip, uint addr, int alen, uchar * buffer, int len)
371{
wdenkfc3e2162003-10-08 22:33:00 +0000372 uchar xaddr[4];
373 int ret;
wdenk1cb8e982003-03-06 21:55:29 +0000374
wdenkfc3e2162003-10-08 22:33:00 +0000375 if (alen > 4) {
376 printf ("I2C read: addr len %d not supported\n", alen);
377 return 1;
378 }
wdenk1cb8e982003-03-06 21:55:29 +0000379
wdenkfc3e2162003-10-08 22:33:00 +0000380 if (alen > 0) {
381 xaddr[0] = (addr >> 24) & 0xFF;
382 xaddr[1] = (addr >> 16) & 0xFF;
383 xaddr[2] = (addr >> 8) & 0xFF;
384 xaddr[3] = addr & 0xFF;
385 }
wdenk1cb8e982003-03-06 21:55:29 +0000386
387#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
wdenkfc3e2162003-10-08 22:33:00 +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 */
399 if (alen > 0)
400 chip |= ((addr >> (alen * 8)) & CFG_I2C_EEPROM_ADDR_OVERFLOW);
wdenk1cb8e982003-03-06 21:55:29 +0000401#endif
wdenkfc3e2162003-10-08 22:33:00 +0000402 if ((ret =
403 i2c_transfer (I2C_READ, chip << 1, &xaddr[4 - alen], alen,
404 buffer, len)) != 0) {
405 printf ("I2c read: failed %d\n", ret);
406 return 1;
407 }
408 return 0;
wdenk1cb8e982003-03-06 21:55:29 +0000409}
410
411int i2c_write (uchar chip, uint addr, int alen, uchar * buffer, int len)
412{
wdenkfc3e2162003-10-08 22:33:00 +0000413 uchar xaddr[4];
wdenk1cb8e982003-03-06 21:55:29 +0000414
wdenkfc3e2162003-10-08 22:33:00 +0000415 if (alen > 4) {
416 printf ("I2C write: addr len %d not supported\n", alen);
417 return 1;
418 }
wdenk1cb8e982003-03-06 21:55:29 +0000419
wdenkfc3e2162003-10-08 22:33:00 +0000420 if (alen > 0) {
421 xaddr[0] = (addr >> 24) & 0xFF;
422 xaddr[1] = (addr >> 16) & 0xFF;
423 xaddr[2] = (addr >> 8) & 0xFF;
424 xaddr[3] = addr & 0xFF;
425 }
wdenk1cb8e982003-03-06 21:55:29 +0000426#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
wdenkfc3e2162003-10-08 22:33:00 +0000427 /*
428 * EEPROM chips that implement "address overflow" are ones
429 * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
430 * address and the extra bits end up in the "chip address"
431 * bit slots. This makes a 24WC08 (1Kbyte) chip look like
432 * four 256 byte chips.
433 *
434 * Note that we consider the length of the address field to
435 * still be one byte because the extra address bits are
436 * hidden in the chip address.
437 */
438 if (alen > 0)
439 chip |= ((addr >> (alen * 8)) & CFG_I2C_EEPROM_ADDR_OVERFLOW);
wdenk1cb8e982003-03-06 21:55:29 +0000440#endif
wdenkfc3e2162003-10-08 22:33:00 +0000441 return (i2c_transfer
442 (I2C_WRITE, chip << 1, &xaddr[4 - alen], alen, buffer,
443 len) != 0);
wdenk1cb8e982003-03-06 21:55:29 +0000444}
wdenk1cb8e982003-03-06 21:55:29 +0000445#endif /* CONFIG_HARD_I2C */
446
447#endif /* CONFIG_DRIVER_S3C24X0_I2C */