xref: /openbmc/u-boot/drivers/i2c/kona_i2c.c (revision 9f2ec3f5)
1 /*
2  * Copyright 2013 Broadcom Corporation.
3  *
4  * SPDX-License-Identifier:      GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <asm/io.h>
9 #include <asm/errno.h>
10 #include <asm/arch/sysmap.h>
11 #include <asm/kona-common/clk.h>
12 #include <i2c.h>
13 
14 /* Hardware register offsets and field defintions */
15 #define CS_OFFSET				0x00000020
16 #define CS_ACK_SHIFT				3
17 #define CS_ACK_MASK				0x00000008
18 #define CS_ACK_CMD_GEN_START			0x00000000
19 #define CS_ACK_CMD_GEN_RESTART			0x00000001
20 #define CS_CMD_SHIFT				1
21 #define CS_CMD_CMD_NO_ACTION			0x00000000
22 #define CS_CMD_CMD_START_RESTART		0x00000001
23 #define CS_CMD_CMD_STOP				0x00000002
24 #define CS_EN_SHIFT				0
25 #define CS_EN_CMD_ENABLE_BSC			0x00000001
26 
27 #define TIM_OFFSET				0x00000024
28 #define TIM_PRESCALE_SHIFT			6
29 #define TIM_P_SHIFT				3
30 #define TIM_NO_DIV_SHIFT			2
31 #define TIM_DIV_SHIFT				0
32 
33 #define DAT_OFFSET				0x00000028
34 
35 #define TOUT_OFFSET				0x0000002c
36 
37 #define TXFCR_OFFSET				0x0000003c
38 #define TXFCR_FIFO_FLUSH_MASK			0x00000080
39 #define TXFCR_FIFO_EN_MASK			0x00000040
40 
41 #define IER_OFFSET				0x00000044
42 #define IER_READ_COMPLETE_INT_MASK		0x00000010
43 #define IER_I2C_INT_EN_MASK			0x00000008
44 #define IER_FIFO_INT_EN_MASK			0x00000002
45 #define IER_NOACK_EN_MASK			0x00000001
46 
47 #define ISR_OFFSET				0x00000048
48 #define ISR_RESERVED_MASK			0xffffff60
49 #define ISR_CMDBUSY_MASK			0x00000080
50 #define ISR_READ_COMPLETE_MASK			0x00000010
51 #define ISR_SES_DONE_MASK			0x00000008
52 #define ISR_ERR_MASK				0x00000004
53 #define ISR_TXFIFOEMPTY_MASK			0x00000002
54 #define ISR_NOACK_MASK				0x00000001
55 
56 #define CLKEN_OFFSET				0x0000004c
57 #define CLKEN_AUTOSENSE_OFF_MASK		0x00000080
58 #define CLKEN_M_SHIFT				4
59 #define CLKEN_N_SHIFT				1
60 #define CLKEN_CLKEN_MASK			0x00000001
61 
62 #define FIFO_STATUS_OFFSET			0x00000054
63 #define FIFO_STATUS_RXFIFO_EMPTY_MASK		0x00000004
64 #define FIFO_STATUS_TXFIFO_EMPTY_MASK		0x00000010
65 
66 #define HSTIM_OFFSET				0x00000058
67 #define HSTIM_HS_MODE_MASK			0x00008000
68 #define HSTIM_HS_HOLD_SHIFT			10
69 #define HSTIM_HS_HIGH_PHASE_SHIFT		5
70 #define HSTIM_HS_SETUP_SHIFT			0
71 
72 #define PADCTL_OFFSET				0x0000005c
73 #define PADCTL_PAD_OUT_EN_MASK			0x00000004
74 
75 #define RXFCR_OFFSET				0x00000068
76 #define RXFCR_NACK_EN_SHIFT			7
77 #define RXFCR_READ_COUNT_SHIFT			0
78 #define RXFIFORDOUT_OFFSET			0x0000006c
79 
80 /* Locally used constants */
81 #define MAX_RX_FIFO_SIZE		64U	/* bytes */
82 #define MAX_TX_FIFO_SIZE		64U	/* bytes */
83 
84 #define I2C_TIMEOUT			100000	/* usecs */
85 
86 #define WAIT_INT_CHK			100	/* usecs */
87 #if I2C_TIMEOUT % WAIT_INT_CHK
88 #error I2C_TIMEOUT must be a multiple of WAIT_INT_CHK
89 #endif
90 
91 /* Operations that can be commanded to the controller */
92 enum bcm_kona_cmd_t {
93 	BCM_CMD_NOACTION = 0,
94 	BCM_CMD_START,
95 	BCM_CMD_RESTART,
96 	BCM_CMD_STOP,
97 };
98 
99 enum bus_speed_index {
100 	BCM_SPD_100K = 0,
101 	BCM_SPD_400K,
102 	BCM_SPD_1MHZ,
103 };
104 
105 /* Internal divider settings for standard mode, fast mode and fast mode plus */
106 struct bus_speed_cfg {
107 	uint8_t time_m;		/* Number of cycles for setup time */
108 	uint8_t time_n;		/* Number of cycles for hold time */
109 	uint8_t prescale;	/* Prescale divider */
110 	uint8_t time_p;		/* Timing coefficient */
111 	uint8_t no_div;		/* Disable clock divider */
112 	uint8_t time_div;	/* Post-prescale divider */
113 };
114 
115 static const struct bus_speed_cfg std_cfg_table[] = {
116 	[BCM_SPD_100K] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
117 	[BCM_SPD_400K] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
118 	[BCM_SPD_1MHZ] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
119 };
120 
121 struct bcm_kona_i2c_dev {
122 	void *base;
123 	uint speed;
124 	const struct bus_speed_cfg *std_cfg;
125 };
126 
127 /* Keep these two defines in sync */
128 #define DEF_SPD 100000
129 #define DEF_SPD_ENUM BCM_SPD_100K
130 
131 #define DEF_DEVICE(num) \
132 {(void *)CONFIG_SYS_I2C_BASE##num, DEF_SPD, &std_cfg_table[DEF_SPD_ENUM]}
133 
134 static struct bcm_kona_i2c_dev g_i2c_devs[CONFIG_SYS_MAX_I2C_BUS] = {
135 #ifdef CONFIG_SYS_I2C_BASE0
136 	DEF_DEVICE(0),
137 #endif
138 #ifdef CONFIG_SYS_I2C_BASE1
139 	DEF_DEVICE(1),
140 #endif
141 #ifdef CONFIG_SYS_I2C_BASE2
142 	DEF_DEVICE(2),
143 #endif
144 #ifdef CONFIG_SYS_I2C_BASE3
145 	DEF_DEVICE(3),
146 #endif
147 #ifdef CONFIG_SYS_I2C_BASE4
148 	DEF_DEVICE(4),
149 #endif
150 #ifdef CONFIG_SYS_I2C_BASE5
151 	DEF_DEVICE(5),
152 #endif
153 };
154 
155 #define I2C_M_TEN	0x0010	/* ten bit address */
156 #define I2C_M_RD	0x0001	/* read data */
157 #define I2C_M_NOSTART	0x4000	/* no restart between msgs */
158 
159 struct i2c_msg {
160 	uint16_t addr;
161 	uint16_t flags;
162 	uint16_t len;
163 	uint8_t *buf;
164 };
165 
166 static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev,
167 					  enum bcm_kona_cmd_t cmd)
168 {
169 	debug("%s, %d\n", __func__, cmd);
170 
171 	switch (cmd) {
172 	case BCM_CMD_NOACTION:
173 		writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) |
174 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
175 		       dev->base + CS_OFFSET);
176 		break;
177 
178 	case BCM_CMD_START:
179 		writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) |
180 		       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
181 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
182 		       dev->base + CS_OFFSET);
183 		break;
184 
185 	case BCM_CMD_RESTART:
186 		writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) |
187 		       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
188 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
189 		       dev->base + CS_OFFSET);
190 		break;
191 
192 	case BCM_CMD_STOP:
193 		writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) |
194 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
195 		       dev->base + CS_OFFSET);
196 		break;
197 
198 	default:
199 		printf("Unknown command %d\n", cmd);
200 	}
201 }
202 
203 static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev)
204 {
205 	writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK,
206 	       dev->base + CLKEN_OFFSET);
207 }
208 
209 static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev)
210 {
211 	writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK,
212 	       dev->base + CLKEN_OFFSET);
213 }
214 
215 /* Wait until at least one of the mask bit(s) are set */
216 static unsigned long wait_for_int_timeout(struct bcm_kona_i2c_dev *dev,
217 					  unsigned long time_left,
218 					  uint32_t mask)
219 {
220 	uint32_t status;
221 
222 	while (time_left) {
223 		status = readl(dev->base + ISR_OFFSET);
224 
225 		if ((status & ~ISR_RESERVED_MASK) == 0) {
226 			debug("Bogus I2C interrupt 0x%x\n", status);
227 			continue;
228 		}
229 
230 		/* Must flush the TX FIFO when NAK detected */
231 		if (status & ISR_NOACK_MASK)
232 			writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
233 			       dev->base + TXFCR_OFFSET);
234 
235 		writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET);
236 
237 		if (status & mask) {
238 			/* We are done since one of the mask bits are set */
239 			return time_left;
240 		}
241 		udelay(WAIT_INT_CHK);
242 		time_left -= WAIT_INT_CHK;
243 	}
244 	return 0;
245 }
246 
247 /* Send command to I2C bus */
248 static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev,
249 				 enum bcm_kona_cmd_t cmd)
250 {
251 	int rc = 0;
252 	unsigned long time_left = I2C_TIMEOUT;
253 
254 	/* Send the command */
255 	bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd);
256 
257 	/* Wait for transaction to finish or timeout */
258 	time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
259 
260 	if (!time_left) {
261 		printf("controller timed out\n");
262 		rc = -ETIMEDOUT;
263 	}
264 
265 	/* Clear command */
266 	bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
267 
268 	return rc;
269 }
270 
271 /* Read a single RX FIFO worth of data from the i2c bus */
272 static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev,
273 					 uint8_t *buf, unsigned int len,
274 					 unsigned int last_byte_nak)
275 {
276 	unsigned long time_left = I2C_TIMEOUT;
277 
278 	/* Start the RX FIFO */
279 	writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) |
280 	       (len << RXFCR_READ_COUNT_SHIFT), dev->base + RXFCR_OFFSET);
281 
282 	/* Wait for FIFO read to complete */
283 	time_left =
284 	    wait_for_int_timeout(dev, time_left, IER_READ_COMPLETE_INT_MASK);
285 
286 	if (!time_left) {
287 		printf("RX FIFO time out\n");
288 		return -EREMOTEIO;
289 	}
290 
291 	/* Read data from FIFO */
292 	for (; len > 0; len--, buf++)
293 		*buf = readl(dev->base + RXFIFORDOUT_OFFSET);
294 
295 	return 0;
296 }
297 
298 /* Read any amount of data using the RX FIFO from the i2c bus */
299 static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
300 				  struct i2c_msg *msg)
301 {
302 	unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
303 	unsigned int last_byte_nak = 0;
304 	unsigned int bytes_read = 0;
305 	int rc;
306 
307 	uint8_t *tmp_buf = msg->buf;
308 
309 	while (bytes_read < msg->len) {
310 		if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) {
311 			last_byte_nak = 1;	/* NAK last byte of transfer */
312 			bytes_to_read = msg->len - bytes_read;
313 		}
314 
315 		rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read,
316 						   last_byte_nak);
317 		if (rc < 0)
318 			return -EREMOTEIO;
319 
320 		bytes_read += bytes_to_read;
321 		tmp_buf += bytes_to_read;
322 	}
323 
324 	return 0;
325 }
326 
327 /* Write a single byte of data to the i2c bus */
328 static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data,
329 				   unsigned int nak_expected)
330 {
331 	unsigned long time_left = I2C_TIMEOUT;
332 	unsigned int nak_received;
333 
334 	/* Clear pending session done interrupt */
335 	writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET);
336 
337 	/* Send one byte of data */
338 	writel(data, dev->base + DAT_OFFSET);
339 
340 	time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
341 
342 	if (!time_left) {
343 		debug("controller timed out\n");
344 		return -ETIMEDOUT;
345 	}
346 
347 	nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0;
348 
349 	if (nak_received ^ nak_expected) {
350 		debug("unexpected NAK/ACK\n");
351 		return -EREMOTEIO;
352 	}
353 
354 	return 0;
355 }
356 
357 /* Write a single TX FIFO worth of data to the i2c bus */
358 static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev,
359 					  uint8_t *buf, unsigned int len)
360 {
361 	int k;
362 	unsigned long time_left = I2C_TIMEOUT;
363 	unsigned int fifo_status;
364 
365 	/* Write data into FIFO */
366 	for (k = 0; k < len; k++)
367 		writel(buf[k], (dev->base + DAT_OFFSET));
368 
369 	/* Wait for FIFO to empty */
370 	do {
371 		time_left =
372 		    wait_for_int_timeout(dev, time_left,
373 					 (IER_FIFO_INT_EN_MASK |
374 					  IER_NOACK_EN_MASK));
375 		fifo_status = readl(dev->base + FIFO_STATUS_OFFSET);
376 	} while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK));
377 
378 	/* Check if there was a NAK */
379 	if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) {
380 		printf("unexpected NAK\n");
381 		return -EREMOTEIO;
382 	}
383 
384 	/* Check if a timeout occured */
385 	if (!time_left) {
386 		printf("completion timed out\n");
387 		return -EREMOTEIO;
388 	}
389 
390 	return 0;
391 }
392 
393 /* Write any amount of data using TX FIFO to the i2c bus */
394 static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
395 				   struct i2c_msg *msg)
396 {
397 	unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
398 	unsigned int bytes_written = 0;
399 	int rc;
400 
401 	uint8_t *tmp_buf = msg->buf;
402 
403 	while (bytes_written < msg->len) {
404 		if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE)
405 			bytes_to_write = msg->len - bytes_written;
406 
407 		rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf,
408 						    bytes_to_write);
409 		if (rc < 0)
410 			return -EREMOTEIO;
411 
412 		bytes_written += bytes_to_write;
413 		tmp_buf += bytes_to_write;
414 	}
415 
416 	return 0;
417 }
418 
419 /* Send i2c address */
420 static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev,
421 				struct i2c_msg *msg)
422 {
423 	unsigned char addr;
424 
425 	if (msg->flags & I2C_M_TEN) {
426 		/* First byte is 11110XX0 where XX is upper 2 bits */
427 		addr = 0xf0 | ((msg->addr & 0x300) >> 7);
428 		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
429 			return -EREMOTEIO;
430 
431 		/* Second byte is the remaining 8 bits */
432 		addr = msg->addr & 0xff;
433 		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
434 			return -EREMOTEIO;
435 
436 		if (msg->flags & I2C_M_RD) {
437 			/* For read, send restart command */
438 			if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0)
439 				return -EREMOTEIO;
440 
441 			/* Then re-send the first byte with the read bit set */
442 			addr = 0xf0 | ((msg->addr & 0x300) >> 7) | 0x01;
443 			if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
444 				return -EREMOTEIO;
445 		}
446 	} else {
447 		addr = msg->addr << 1;
448 
449 		if (msg->flags & I2C_M_RD)
450 			addr |= 1;
451 
452 		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
453 			return -EREMOTEIO;
454 	}
455 
456 	return 0;
457 }
458 
459 static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev)
460 {
461 	writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK,
462 	       dev->base + CLKEN_OFFSET);
463 }
464 
465 static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
466 {
467 	writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK,
468 	       dev->base + HSTIM_OFFSET);
469 
470 	writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) |
471 	       (dev->std_cfg->time_p << TIM_P_SHIFT) |
472 	       (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) |
473 	       (dev->std_cfg->time_div << TIM_DIV_SHIFT),
474 	       dev->base + TIM_OFFSET);
475 
476 	writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) |
477 	       (dev->std_cfg->time_n << CLKEN_N_SHIFT) |
478 	       CLKEN_CLKEN_MASK, dev->base + CLKEN_OFFSET);
479 }
480 
481 /* Master transfer function */
482 static int bcm_kona_i2c_xfer(struct bcm_kona_i2c_dev *dev,
483 			     struct i2c_msg msgs[], int num)
484 {
485 	struct i2c_msg *pmsg;
486 	int rc = 0;
487 	int i;
488 
489 	/* Enable pad output */
490 	writel(0, dev->base + PADCTL_OFFSET);
491 
492 	/* Enable internal clocks */
493 	bcm_kona_i2c_enable_clock(dev);
494 
495 	/* Send start command */
496 	rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START);
497 	if (rc < 0) {
498 		printf("Start command failed rc = %d\n", rc);
499 		goto xfer_disable_pad;
500 	}
501 
502 	/* Loop through all messages */
503 	for (i = 0; i < num; i++) {
504 		pmsg = &msgs[i];
505 
506 		/* Send restart for subsequent messages */
507 		if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) {
508 			rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
509 			if (rc < 0) {
510 				printf("restart cmd failed rc = %d\n", rc);
511 				goto xfer_send_stop;
512 			}
513 		}
514 
515 		/* Send slave address */
516 		if (!(pmsg->flags & I2C_M_NOSTART)) {
517 			rc = bcm_kona_i2c_do_addr(dev, pmsg);
518 			if (rc < 0) {
519 				debug("NAK from addr %2.2x msg#%d rc = %d\n",
520 				      pmsg->addr, i, rc);
521 				goto xfer_send_stop;
522 			}
523 		}
524 
525 		/* Perform data transfer */
526 		if (pmsg->flags & I2C_M_RD) {
527 			rc = bcm_kona_i2c_read_fifo(dev, pmsg);
528 			if (rc < 0) {
529 				printf("read failure\n");
530 				goto xfer_send_stop;
531 			}
532 		} else {
533 			rc = bcm_kona_i2c_write_fifo(dev, pmsg);
534 			if (rc < 0) {
535 				printf("write failure");
536 				goto xfer_send_stop;
537 			}
538 		}
539 	}
540 
541 	rc = num;
542 
543 xfer_send_stop:
544 	/* Send a STOP command */
545 	bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
546 
547 xfer_disable_pad:
548 	/* Disable pad output */
549 	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
550 
551 	/* Stop internal clock */
552 	bcm_kona_i2c_disable_clock(dev);
553 
554 	return rc;
555 }
556 
557 static uint bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev,
558 					  uint speed)
559 {
560 	switch (speed) {
561 	case 100000:
562 		dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
563 		break;
564 	case 400000:
565 		dev->std_cfg = &std_cfg_table[BCM_SPD_400K];
566 		break;
567 	case 1000000:
568 		dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ];
569 		break;
570 	default:
571 		printf("%d hz bus speed not supported\n", speed);
572 		return -EINVAL;
573 	}
574 	dev->speed = speed;
575 	return 0;
576 }
577 
578 static void bcm_kona_i2c_init(struct bcm_kona_i2c_dev *dev)
579 {
580 	/* Parse bus speed */
581 	bcm_kona_i2c_assign_bus_speed(dev, dev->speed);
582 
583 	/* Enable internal clocks */
584 	bcm_kona_i2c_enable_clock(dev);
585 
586 	/* Configure internal dividers */
587 	bcm_kona_i2c_config_timing(dev);
588 
589 	/* Disable timeout */
590 	writel(0, dev->base + TOUT_OFFSET);
591 
592 	/* Enable autosense */
593 	bcm_kona_i2c_enable_autosense(dev);
594 
595 	/* Enable TX FIFO */
596 	writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
597 	       dev->base + TXFCR_OFFSET);
598 
599 	/* Mask all interrupts */
600 	writel(0, dev->base + IER_OFFSET);
601 
602 	/* Clear all pending interrupts */
603 	writel(ISR_CMDBUSY_MASK |
604 	       ISR_READ_COMPLETE_MASK |
605 	       ISR_SES_DONE_MASK |
606 	       ISR_ERR_MASK |
607 	       ISR_TXFIFOEMPTY_MASK | ISR_NOACK_MASK, dev->base + ISR_OFFSET);
608 
609 	/* Enable the controller but leave it idle */
610 	bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
611 
612 	/* Disable pad output */
613 	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
614 }
615 
616 /*
617  * uboot layer
618  */
619 struct bcm_kona_i2c_dev *kona_get_dev(struct i2c_adapter *adap)
620 {
621 	return &g_i2c_devs[adap->hwadapnr];
622 }
623 
624 static void kona_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
625 {
626 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
627 
628 	if (clk_bsc_enable(dev->base))
629 		return;
630 
631 	bcm_kona_i2c_init(dev);
632 }
633 
634 static int kona_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
635 			 int alen, uchar *buffer, int len)
636 {
637 	/* msg[0] writes the addr, msg[1] reads the data */
638 	struct i2c_msg msg[2];
639 	unsigned char msgbuf0[64];
640 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
641 
642 	msg[0].addr = chip;
643 	msg[0].flags = 0;
644 	msg[0].len = 1;
645 	msg[0].buf = msgbuf0;	/* msgbuf0 contains incrementing reg addr */
646 
647 	msg[1].addr = chip;
648 	msg[1].flags = I2C_M_RD;
649 	/* msg[1].buf dest ptr increments each read */
650 
651 	msgbuf0[0] = (unsigned char)addr;
652 	msg[1].buf = buffer;
653 	msg[1].len = len;
654 	if (bcm_kona_i2c_xfer(dev, msg, 2) < 0) {
655 		/* Sending 2 i2c messages */
656 		kona_i2c_init(adap, adap->speed, adap->slaveaddr);
657 		debug("I2C read: I/O error\n");
658 		return -EIO;
659 	}
660 	return 0;
661 }
662 
663 static int kona_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
664 			  int alen, uchar *buffer, int len)
665 {
666 	struct i2c_msg msg[0];
667 	unsigned char msgbuf0[64];
668 	unsigned int i;
669 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
670 
671 	msg[0].addr = chip;
672 	msg[0].flags = 0;
673 	msg[0].len = 2;		/* addr byte plus data */
674 	msg[0].buf = msgbuf0;
675 
676 	for (i = 0; i < len; i++) {
677 		msgbuf0[0] = addr++;
678 		msgbuf0[1] = buffer[i];
679 		if (bcm_kona_i2c_xfer(dev, msg, 1) < 0) {
680 			kona_i2c_init(adap, adap->speed, adap->slaveaddr);
681 			debug("I2C write: I/O error\n");
682 			return -EIO;
683 		}
684 	}
685 	return 0;
686 }
687 
688 static int kona_i2c_probe(struct i2c_adapter *adap, uchar chip)
689 {
690 	uchar tmp;
691 
692 	/*
693 	 * read addr 0x0 of the given chip.
694 	 */
695 	return kona_i2c_read(adap, chip, 0x0, 1, &tmp, 1);
696 }
697 
698 static uint kona_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
699 {
700 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
701 	return bcm_kona_i2c_assign_bus_speed(dev, speed);
702 }
703 
704 /*
705  * Register kona i2c adapters. Keep the order below so
706  * that the bus number matches the adapter number.
707  */
708 #define DEF_ADAPTER(num) \
709 U_BOOT_I2C_ADAP_COMPLETE(kona##num, kona_i2c_init, kona_i2c_probe, \
710 			 kona_i2c_read, kona_i2c_write, \
711 			 kona_i2c_set_bus_speed, DEF_SPD, 0x00, num)
712 
713 #ifdef CONFIG_SYS_I2C_BASE0
714 	DEF_ADAPTER(0)
715 #endif
716 #ifdef CONFIG_SYS_I2C_BASE1
717 	DEF_ADAPTER(1)
718 #endif
719 #ifdef CONFIG_SYS_I2C_BASE2
720 	DEF_ADAPTER(2)
721 #endif
722 #ifdef CONFIG_SYS_I2C_BASE3
723 	DEF_ADAPTER(3)
724 #endif
725 #ifdef CONFIG_SYS_I2C_BASE4
726 	DEF_ADAPTER(4)
727 #endif
728 #ifdef CONFIG_SYS_I2C_BASE5
729 	DEF_ADAPTER(5)
730 #endif
731