4 * Copyright (c) 2004 Texas Instruments
6 * This package is free software; you can redistribute it and/or
7 * modify it under the terms of the license found in the file
8 * named COPYING that should have accompanied this file.
10 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
11 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
12 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
14 * Author: Jian Zhang jzhang@ti.com, Texas Instruments
16 * Copyright (c) 2003 Wolfgang Denk, wd@denx.de
17 * Rewritten to fit into the current U-Boot framework
19 * Adapted for OMAP2420 I2C, r-woodruff2@ti.com
25 #include <asm/arch/i2c.h>
28 #include "omap24xx_i2c.h"
30 DECLARE_GLOBAL_DATA_PTR;
32 #define I2C_TIMEOUT 1000
34 static void wait_for_bb(void);
35 static u16 wait_for_pin(void);
36 static void flush_fifo(void);
38 static struct i2c *i2c_base = (struct i2c *)I2C_DEFAULT_BASE;
40 static unsigned int bus_initialized[I2C_BUS_MAX];
41 static unsigned int current_bus;
43 void i2c_init(int speed, int slaveadd)
45 int psc, fsscll, fssclh;
46 int hsscll = 0, hssclh = 0;
48 int timeout = I2C_TIMEOUT;
50 /* Only handle standard, fast and high speeds */
51 if ((speed != OMAP_I2C_STANDARD) &&
52 (speed != OMAP_I2C_FAST_MODE) &&
53 (speed != OMAP_I2C_HIGH_SPEED)) {
54 printf("Error : I2C unsupported speed %d\n", speed);
58 psc = I2C_IP_CLK / I2C_INTERNAL_SAMPLING_CLK;
60 if (psc < I2C_PSC_MIN) {
61 printf("Error : I2C unsupported prescalar %d\n", psc);
65 if (speed == OMAP_I2C_HIGH_SPEED) {
68 /* For first phase of HS mode */
69 fsscll = fssclh = I2C_INTERNAL_SAMPLING_CLK /
70 (2 * OMAP_I2C_FAST_MODE);
72 fsscll -= I2C_HIGHSPEED_PHASE_ONE_SCLL_TRIM;
73 fssclh -= I2C_HIGHSPEED_PHASE_ONE_SCLH_TRIM;
74 if (((fsscll < 0) || (fssclh < 0)) ||
75 ((fsscll > 255) || (fssclh > 255))) {
76 printf("Error : I2C initializing first phase clock\n");
80 /* For second phase of HS mode */
81 hsscll = hssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
83 hsscll -= I2C_HIGHSPEED_PHASE_TWO_SCLL_TRIM;
84 hssclh -= I2C_HIGHSPEED_PHASE_TWO_SCLH_TRIM;
85 if (((fsscll < 0) || (fssclh < 0)) ||
86 ((fsscll > 255) || (fssclh > 255))) {
87 printf("Error : I2C initializing second phase clock\n");
91 scll = (unsigned int)hsscll << 8 | (unsigned int)fsscll;
92 sclh = (unsigned int)hssclh << 8 | (unsigned int)fssclh;
95 /* Standard and fast speed */
96 fsscll = fssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
98 fsscll -= I2C_FASTSPEED_SCLL_TRIM;
99 fssclh -= I2C_FASTSPEED_SCLH_TRIM;
100 if (((fsscll < 0) || (fssclh < 0)) ||
101 ((fsscll > 255) || (fssclh > 255))) {
102 printf("Error : I2C initializing clock\n");
106 scll = (unsigned int)fsscll;
107 sclh = (unsigned int)fssclh;
110 if (readw(&i2c_base->con) & I2C_CON_EN) {
111 writew(0, &i2c_base->con);
115 writew(0x2, &i2c_base->sysc); /* for ES2 after soft reset */
118 writew(I2C_CON_EN, &i2c_base->con);
119 while (!(readw(&i2c_base->syss) & I2C_SYSS_RDONE) && timeout--) {
121 printf("ERROR: Timeout in soft-reset\n");
127 writew(0, &i2c_base->con);
128 writew(psc, &i2c_base->psc);
129 writew(scll, &i2c_base->scll);
130 writew(sclh, &i2c_base->sclh);
133 writew(slaveadd, &i2c_base->oa);
134 writew(I2C_CON_EN, &i2c_base->con);
136 /* have to enable intrrupts or OMAP i2c module doesn't work */
137 writew(I2C_IE_XRDY_IE | I2C_IE_RRDY_IE | I2C_IE_ARDY_IE |
138 I2C_IE_NACK_IE | I2C_IE_AL_IE, &i2c_base->ie);
141 writew(0xFFFF, &i2c_base->stat);
142 writew(0, &i2c_base->cnt);
144 if (gd->flags & GD_FLG_RELOC)
145 bus_initialized[current_bus] = 1;
148 static int i2c_read_byte(u8 devaddr, u8 regoffset, u8 *value)
153 /* wait until bus not busy */
157 writew(1, &i2c_base->cnt);
158 /* set slave address */
159 writew(devaddr, &i2c_base->sa);
160 /* no stop bit needed here */
161 writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
162 I2C_CON_TRX, &i2c_base->con);
164 /* send register offset */
166 status = wait_for_pin();
167 if (status == 0 || status & I2C_STAT_NACK) {
171 if (status & I2C_STAT_XRDY) {
172 /* Important: have to use byte access */
173 writeb(regoffset, &i2c_base->data);
174 writew(I2C_STAT_XRDY, &i2c_base->stat);
176 if (status & I2C_STAT_ARDY) {
177 writew(I2C_STAT_ARDY, &i2c_base->stat);
182 /* set slave address */
183 writew(devaddr, &i2c_base->sa);
184 /* read one byte from slave */
185 writew(1, &i2c_base->cnt);
186 /* need stop bit here */
187 writew(I2C_CON_EN | I2C_CON_MST |
188 I2C_CON_STT | I2C_CON_STP,
193 status = wait_for_pin();
194 if (status == 0 || status & I2C_STAT_NACK) {
198 if (status & I2C_STAT_RRDY) {
199 #if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
200 defined(CONFIG_OMAP44XX)
201 *value = readb(&i2c_base->data);
203 *value = readw(&i2c_base->data);
205 writew(I2C_STAT_RRDY, &i2c_base->stat);
207 if (status & I2C_STAT_ARDY) {
208 writew(I2C_STAT_ARDY, &i2c_base->stat);
215 writew(0xFFFF, &i2c_base->stat);
216 writew(0, &i2c_base->cnt);
220 static void flush_fifo(void)
223 /* note: if you try and read data when its not there or ready
224 * you get a bus error
227 stat = readw(&i2c_base->stat);
228 if (stat == I2C_STAT_RRDY) {
229 #if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
230 defined(CONFIG_OMAP44XX)
231 readb(&i2c_base->data);
233 readw(&i2c_base->data);
235 writew(I2C_STAT_RRDY, &i2c_base->stat);
242 int i2c_probe(uchar chip)
245 int res = 1; /* default = fail */
247 if (chip == readw(&i2c_base->oa))
250 /* wait until bus not busy */
253 /* try to write one byte */
254 writew(1, &i2c_base->cnt);
255 /* set slave address */
256 writew(chip, &i2c_base->sa);
257 /* stop bit needed here */
258 writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
259 I2C_CON_STP, &i2c_base->con);
261 status = wait_for_pin();
263 /* check for ACK (!NAK) */
264 if (!(status & I2C_STAT_NACK))
267 /* abort transfer (force idle state) */
268 writew(0, &i2c_base->con);
271 /* don't allow any more data in... we don't want it. */
272 writew(0, &i2c_base->cnt);
273 writew(0xFFFF, &i2c_base->stat);
277 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
282 printf("I2C read: addr len %d not supported\n", alen);
286 if (addr + len > 256) {
287 printf("I2C read: address out of range\n");
291 for (i = 0; i < len; i++) {
292 if (i2c_read_byte(chip, addr + i, &buffer[i])) {
293 printf("I2C read: I/O error\n");
294 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
302 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
309 printf("I2C write: addr len %d not supported\n", alen);
313 if (addr + len > 256) {
314 printf("I2C write: address 0x%x + 0x%x out of range\n",
319 /* wait until bus not busy */
322 /* start address phase - will write regoffset + len bytes data */
323 /* TODO consider case when !CONFIG_OMAP243X/34XX/44XX */
324 writew(alen + len, &i2c_base->cnt);
325 /* set slave address */
326 writew(chip, &i2c_base->sa);
327 /* stop bit needed here */
328 writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
329 I2C_CON_STP, &i2c_base->con);
331 /* Send address byte */
332 status = wait_for_pin();
334 if (status == 0 || status & I2C_STAT_NACK) {
336 printf("error waiting for i2c address ACK (status=0x%x)\n",
341 if (status & I2C_STAT_XRDY) {
342 writeb(addr & 0xFF, &i2c_base->data);
343 writew(I2C_STAT_XRDY, &i2c_base->stat);
346 printf("i2c bus not ready for transmit (status=0x%x)\n",
351 /* address phase is over, now write data */
352 for (i = 0; i < len; i++) {
353 status = wait_for_pin();
355 if (status == 0 || status & I2C_STAT_NACK) {
357 printf("i2c error waiting for data ACK (status=0x%x)\n",
362 if (status & I2C_STAT_XRDY) {
363 writeb(buffer[i], &i2c_base->data);
364 writew(I2C_STAT_XRDY, &i2c_base->stat);
367 printf("i2c bus not ready for Tx (i=%d)\n", i);
374 writew(0xFFFF, &i2c_base->stat);
378 static void wait_for_bb(void)
380 int timeout = I2C_TIMEOUT;
383 writew(0xFFFF, &i2c_base->stat); /* clear current interrupts...*/
384 while ((stat = readw(&i2c_base->stat) & I2C_STAT_BB) && timeout--) {
385 writew(stat, &i2c_base->stat);
390 printf("timed out in wait_for_bb: I2C_STAT=%x\n",
391 readw(&i2c_base->stat));
393 writew(0xFFFF, &i2c_base->stat); /* clear delayed stuff*/
396 static u16 wait_for_pin(void)
399 int timeout = I2C_TIMEOUT;
403 status = readw(&i2c_base->stat);
405 (I2C_STAT_ROVR | I2C_STAT_XUDF | I2C_STAT_XRDY |
406 I2C_STAT_RRDY | I2C_STAT_ARDY | I2C_STAT_NACK |
407 I2C_STAT_AL)) && timeout--);
410 printf("timed out in wait_for_pin: I2C_STAT=%x\n",
411 readw(&i2c_base->stat));
412 writew(0xFFFF, &i2c_base->stat);
419 int i2c_set_bus_num(unsigned int bus)
421 if ((bus < 0) || (bus >= I2C_BUS_MAX)) {
422 printf("Bad bus: %d\n", bus);
428 i2c_base = (struct i2c *)I2C_BASE3;
432 i2c_base = (struct i2c *)I2C_BASE2;
434 i2c_base = (struct i2c *)I2C_BASE1;
438 if (!bus_initialized[current_bus])
439 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
444 int i2c_get_bus_num(void)
446 return (int) current_bus;