xref: /openbmc/u-boot/drivers/i2c/kona_i2c.c (revision d9b23e26)
1 /*
2  * Copyright 2013 Broadcom Corporation.
3  *
4  * SPDX-License-Identifier:      GPL-2.0+
5  *
6  * NOTE: This driver should be converted to driver model before June 2017.
7  * Please see doc/driver-model/i2c-howto.txt for instructions.
8  */
9 
10 #include <common.h>
11 #include <asm/io.h>
12 #include <linux/errno.h>
13 #include <asm/arch/sysmap.h>
14 #include <asm/kona-common/clk.h>
15 #include <i2c.h>
16 
17 /* Hardware register offsets and field defintions */
18 #define CS_OFFSET				0x00000020
19 #define CS_ACK_SHIFT				3
20 #define CS_ACK_MASK				0x00000008
21 #define CS_ACK_CMD_GEN_START			0x00000000
22 #define CS_ACK_CMD_GEN_RESTART			0x00000001
23 #define CS_CMD_SHIFT				1
24 #define CS_CMD_CMD_NO_ACTION			0x00000000
25 #define CS_CMD_CMD_START_RESTART		0x00000001
26 #define CS_CMD_CMD_STOP				0x00000002
27 #define CS_EN_SHIFT				0
28 #define CS_EN_CMD_ENABLE_BSC			0x00000001
29 
30 #define TIM_OFFSET				0x00000024
31 #define TIM_PRESCALE_SHIFT			6
32 #define TIM_P_SHIFT				3
33 #define TIM_NO_DIV_SHIFT			2
34 #define TIM_DIV_SHIFT				0
35 
36 #define DAT_OFFSET				0x00000028
37 
38 #define TOUT_OFFSET				0x0000002c
39 
40 #define TXFCR_OFFSET				0x0000003c
41 #define TXFCR_FIFO_FLUSH_MASK			0x00000080
42 #define TXFCR_FIFO_EN_MASK			0x00000040
43 
44 #define IER_OFFSET				0x00000044
45 #define IER_READ_COMPLETE_INT_MASK		0x00000010
46 #define IER_I2C_INT_EN_MASK			0x00000008
47 #define IER_FIFO_INT_EN_MASK			0x00000002
48 #define IER_NOACK_EN_MASK			0x00000001
49 
50 #define ISR_OFFSET				0x00000048
51 #define ISR_RESERVED_MASK			0xffffff60
52 #define ISR_CMDBUSY_MASK			0x00000080
53 #define ISR_READ_COMPLETE_MASK			0x00000010
54 #define ISR_SES_DONE_MASK			0x00000008
55 #define ISR_ERR_MASK				0x00000004
56 #define ISR_TXFIFOEMPTY_MASK			0x00000002
57 #define ISR_NOACK_MASK				0x00000001
58 
59 #define CLKEN_OFFSET				0x0000004c
60 #define CLKEN_AUTOSENSE_OFF_MASK		0x00000080
61 #define CLKEN_M_SHIFT				4
62 #define CLKEN_N_SHIFT				1
63 #define CLKEN_CLKEN_MASK			0x00000001
64 
65 #define FIFO_STATUS_OFFSET			0x00000054
66 #define FIFO_STATUS_RXFIFO_EMPTY_MASK		0x00000004
67 #define FIFO_STATUS_TXFIFO_EMPTY_MASK		0x00000010
68 
69 #define HSTIM_OFFSET				0x00000058
70 #define HSTIM_HS_MODE_MASK			0x00008000
71 #define HSTIM_HS_HOLD_SHIFT			10
72 #define HSTIM_HS_HIGH_PHASE_SHIFT		5
73 #define HSTIM_HS_SETUP_SHIFT			0
74 
75 #define PADCTL_OFFSET				0x0000005c
76 #define PADCTL_PAD_OUT_EN_MASK			0x00000004
77 
78 #define RXFCR_OFFSET				0x00000068
79 #define RXFCR_NACK_EN_SHIFT			7
80 #define RXFCR_READ_COUNT_SHIFT			0
81 #define RXFIFORDOUT_OFFSET			0x0000006c
82 
83 /* Locally used constants */
84 #define MAX_RX_FIFO_SIZE		64U	/* bytes */
85 #define MAX_TX_FIFO_SIZE		64U	/* bytes */
86 
87 #define I2C_TIMEOUT			100000	/* usecs */
88 
89 #define WAIT_INT_CHK			100	/* usecs */
90 #if I2C_TIMEOUT % WAIT_INT_CHK
91 #error I2C_TIMEOUT must be a multiple of WAIT_INT_CHK
92 #endif
93 
94 /* Operations that can be commanded to the controller */
95 enum bcm_kona_cmd_t {
96 	BCM_CMD_NOACTION = 0,
97 	BCM_CMD_START,
98 	BCM_CMD_RESTART,
99 	BCM_CMD_STOP,
100 };
101 
102 enum bus_speed_index {
103 	BCM_SPD_100K = 0,
104 	BCM_SPD_400K,
105 	BCM_SPD_1MHZ,
106 };
107 
108 /* Internal divider settings for standard mode, fast mode and fast mode plus */
109 struct bus_speed_cfg {
110 	uint8_t time_m;		/* Number of cycles for setup time */
111 	uint8_t time_n;		/* Number of cycles for hold time */
112 	uint8_t prescale;	/* Prescale divider */
113 	uint8_t time_p;		/* Timing coefficient */
114 	uint8_t no_div;		/* Disable clock divider */
115 	uint8_t time_div;	/* Post-prescale divider */
116 };
117 
118 static const struct bus_speed_cfg std_cfg_table[] = {
119 	[BCM_SPD_100K] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
120 	[BCM_SPD_400K] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
121 	[BCM_SPD_1MHZ] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
122 };
123 
124 struct bcm_kona_i2c_dev {
125 	void *base;
126 	uint speed;
127 	const struct bus_speed_cfg *std_cfg;
128 };
129 
130 /* Keep these two defines in sync */
131 #define DEF_SPD 100000
132 #define DEF_SPD_ENUM BCM_SPD_100K
133 
134 #define DEF_DEVICE(num) \
135 {(void *)CONFIG_SYS_I2C_BASE##num, DEF_SPD, &std_cfg_table[DEF_SPD_ENUM]}
136 
137 static struct bcm_kona_i2c_dev g_i2c_devs[CONFIG_SYS_MAX_I2C_BUS] = {
138 #ifdef CONFIG_SYS_I2C_BASE0
139 	DEF_DEVICE(0),
140 #endif
141 #ifdef CONFIG_SYS_I2C_BASE1
142 	DEF_DEVICE(1),
143 #endif
144 #ifdef CONFIG_SYS_I2C_BASE2
145 	DEF_DEVICE(2),
146 #endif
147 #ifdef CONFIG_SYS_I2C_BASE3
148 	DEF_DEVICE(3),
149 #endif
150 #ifdef CONFIG_SYS_I2C_BASE4
151 	DEF_DEVICE(4),
152 #endif
153 #ifdef CONFIG_SYS_I2C_BASE5
154 	DEF_DEVICE(5),
155 #endif
156 };
157 
158 #define I2C_M_TEN	0x0010	/* ten bit address */
159 #define I2C_M_RD	0x0001	/* read data */
160 #define I2C_M_NOSTART	0x4000	/* no restart between msgs */
161 
162 struct kona_i2c_msg {
163 	uint16_t addr;
164 	uint16_t flags;
165 	uint16_t len;
166 	uint8_t *buf;
167 };
168 
169 static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev,
170 					  enum bcm_kona_cmd_t cmd)
171 {
172 	debug("%s, %d\n", __func__, cmd);
173 
174 	switch (cmd) {
175 	case BCM_CMD_NOACTION:
176 		writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) |
177 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
178 		       dev->base + CS_OFFSET);
179 		break;
180 
181 	case BCM_CMD_START:
182 		writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) |
183 		       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
184 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
185 		       dev->base + CS_OFFSET);
186 		break;
187 
188 	case BCM_CMD_RESTART:
189 		writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) |
190 		       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
191 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
192 		       dev->base + CS_OFFSET);
193 		break;
194 
195 	case BCM_CMD_STOP:
196 		writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) |
197 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
198 		       dev->base + CS_OFFSET);
199 		break;
200 
201 	default:
202 		printf("Unknown command %d\n", cmd);
203 	}
204 }
205 
206 static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev)
207 {
208 	writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK,
209 	       dev->base + CLKEN_OFFSET);
210 }
211 
212 static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev)
213 {
214 	writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK,
215 	       dev->base + CLKEN_OFFSET);
216 }
217 
218 /* Wait until at least one of the mask bit(s) are set */
219 static unsigned long wait_for_int_timeout(struct bcm_kona_i2c_dev *dev,
220 					  unsigned long time_left,
221 					  uint32_t mask)
222 {
223 	uint32_t status;
224 
225 	while (time_left) {
226 		status = readl(dev->base + ISR_OFFSET);
227 
228 		if ((status & ~ISR_RESERVED_MASK) == 0) {
229 			debug("Bogus I2C interrupt 0x%x\n", status);
230 			continue;
231 		}
232 
233 		/* Must flush the TX FIFO when NAK detected */
234 		if (status & ISR_NOACK_MASK)
235 			writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
236 			       dev->base + TXFCR_OFFSET);
237 
238 		writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET);
239 
240 		if (status & mask) {
241 			/* We are done since one of the mask bits are set */
242 			return time_left;
243 		}
244 		udelay(WAIT_INT_CHK);
245 		time_left -= WAIT_INT_CHK;
246 	}
247 	return 0;
248 }
249 
250 /* Send command to I2C bus */
251 static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev,
252 				 enum bcm_kona_cmd_t cmd)
253 {
254 	int rc = 0;
255 	unsigned long time_left = I2C_TIMEOUT;
256 
257 	/* Send the command */
258 	bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd);
259 
260 	/* Wait for transaction to finish or timeout */
261 	time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
262 
263 	if (!time_left) {
264 		printf("controller timed out\n");
265 		rc = -ETIMEDOUT;
266 	}
267 
268 	/* Clear command */
269 	bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
270 
271 	return rc;
272 }
273 
274 /* Read a single RX FIFO worth of data from the i2c bus */
275 static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev,
276 					 uint8_t *buf, unsigned int len,
277 					 unsigned int last_byte_nak)
278 {
279 	unsigned long time_left = I2C_TIMEOUT;
280 
281 	/* Start the RX FIFO */
282 	writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) |
283 	       (len << RXFCR_READ_COUNT_SHIFT), dev->base + RXFCR_OFFSET);
284 
285 	/* Wait for FIFO read to complete */
286 	time_left =
287 	    wait_for_int_timeout(dev, time_left, IER_READ_COMPLETE_INT_MASK);
288 
289 	if (!time_left) {
290 		printf("RX FIFO time out\n");
291 		return -EREMOTEIO;
292 	}
293 
294 	/* Read data from FIFO */
295 	for (; len > 0; len--, buf++)
296 		*buf = readl(dev->base + RXFIFORDOUT_OFFSET);
297 
298 	return 0;
299 }
300 
301 /* Read any amount of data using the RX FIFO from the i2c bus */
302 static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
303 				  struct kona_i2c_msg *msg)
304 {
305 	unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
306 	unsigned int last_byte_nak = 0;
307 	unsigned int bytes_read = 0;
308 	int rc;
309 
310 	uint8_t *tmp_buf = msg->buf;
311 
312 	while (bytes_read < msg->len) {
313 		if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) {
314 			last_byte_nak = 1;	/* NAK last byte of transfer */
315 			bytes_to_read = msg->len - bytes_read;
316 		}
317 
318 		rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read,
319 						   last_byte_nak);
320 		if (rc < 0)
321 			return -EREMOTEIO;
322 
323 		bytes_read += bytes_to_read;
324 		tmp_buf += bytes_to_read;
325 	}
326 
327 	return 0;
328 }
329 
330 /* Write a single byte of data to the i2c bus */
331 static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data,
332 				   unsigned int nak_expected)
333 {
334 	unsigned long time_left = I2C_TIMEOUT;
335 	unsigned int nak_received;
336 
337 	/* Clear pending session done interrupt */
338 	writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET);
339 
340 	/* Send one byte of data */
341 	writel(data, dev->base + DAT_OFFSET);
342 
343 	time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
344 
345 	if (!time_left) {
346 		debug("controller timed out\n");
347 		return -ETIMEDOUT;
348 	}
349 
350 	nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0;
351 
352 	if (nak_received ^ nak_expected) {
353 		debug("unexpected NAK/ACK\n");
354 		return -EREMOTEIO;
355 	}
356 
357 	return 0;
358 }
359 
360 /* Write a single TX FIFO worth of data to the i2c bus */
361 static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev,
362 					  uint8_t *buf, unsigned int len)
363 {
364 	int k;
365 	unsigned long time_left = I2C_TIMEOUT;
366 	unsigned int fifo_status;
367 
368 	/* Write data into FIFO */
369 	for (k = 0; k < len; k++)
370 		writel(buf[k], (dev->base + DAT_OFFSET));
371 
372 	/* Wait for FIFO to empty */
373 	do {
374 		time_left =
375 		    wait_for_int_timeout(dev, time_left,
376 					 (IER_FIFO_INT_EN_MASK |
377 					  IER_NOACK_EN_MASK));
378 		fifo_status = readl(dev->base + FIFO_STATUS_OFFSET);
379 	} while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK));
380 
381 	/* Check if there was a NAK */
382 	if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) {
383 		printf("unexpected NAK\n");
384 		return -EREMOTEIO;
385 	}
386 
387 	/* Check if a timeout occurred */
388 	if (!time_left) {
389 		printf("completion timed out\n");
390 		return -EREMOTEIO;
391 	}
392 
393 	return 0;
394 }
395 
396 /* Write any amount of data using TX FIFO to the i2c bus */
397 static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
398 				   struct kona_i2c_msg *msg)
399 {
400 	unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
401 	unsigned int bytes_written = 0;
402 	int rc;
403 
404 	uint8_t *tmp_buf = msg->buf;
405 
406 	while (bytes_written < msg->len) {
407 		if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE)
408 			bytes_to_write = msg->len - bytes_written;
409 
410 		rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf,
411 						    bytes_to_write);
412 		if (rc < 0)
413 			return -EREMOTEIO;
414 
415 		bytes_written += bytes_to_write;
416 		tmp_buf += bytes_to_write;
417 	}
418 
419 	return 0;
420 }
421 
422 /* Send i2c address */
423 static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev,
424 				struct kona_i2c_msg *msg)
425 {
426 	unsigned char addr;
427 
428 	if (msg->flags & I2C_M_TEN) {
429 		/* First byte is 11110XX0 where XX is upper 2 bits */
430 		addr = 0xf0 | ((msg->addr & 0x300) >> 7);
431 		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
432 			return -EREMOTEIO;
433 
434 		/* Second byte is the remaining 8 bits */
435 		addr = msg->addr & 0xff;
436 		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
437 			return -EREMOTEIO;
438 
439 		if (msg->flags & I2C_M_RD) {
440 			/* For read, send restart command */
441 			if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0)
442 				return -EREMOTEIO;
443 
444 			/* Then re-send the first byte with the read bit set */
445 			addr = 0xf0 | ((msg->addr & 0x300) >> 7) | 0x01;
446 			if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
447 				return -EREMOTEIO;
448 		}
449 	} else {
450 		addr = msg->addr << 1;
451 
452 		if (msg->flags & I2C_M_RD)
453 			addr |= 1;
454 
455 		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
456 			return -EREMOTEIO;
457 	}
458 
459 	return 0;
460 }
461 
462 static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev)
463 {
464 	writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK,
465 	       dev->base + CLKEN_OFFSET);
466 }
467 
468 static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
469 {
470 	writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK,
471 	       dev->base + HSTIM_OFFSET);
472 
473 	writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) |
474 	       (dev->std_cfg->time_p << TIM_P_SHIFT) |
475 	       (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) |
476 	       (dev->std_cfg->time_div << TIM_DIV_SHIFT),
477 	       dev->base + TIM_OFFSET);
478 
479 	writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) |
480 	       (dev->std_cfg->time_n << CLKEN_N_SHIFT) |
481 	       CLKEN_CLKEN_MASK, dev->base + CLKEN_OFFSET);
482 }
483 
484 /* Master transfer function */
485 static int bcm_kona_i2c_xfer(struct bcm_kona_i2c_dev *dev,
486 			     struct kona_i2c_msg msgs[], int num)
487 {
488 	struct kona_i2c_msg *pmsg;
489 	int rc = 0;
490 	int i;
491 
492 	/* Enable pad output */
493 	writel(0, dev->base + PADCTL_OFFSET);
494 
495 	/* Enable internal clocks */
496 	bcm_kona_i2c_enable_clock(dev);
497 
498 	/* Send start command */
499 	rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START);
500 	if (rc < 0) {
501 		printf("Start command failed rc = %d\n", rc);
502 		goto xfer_disable_pad;
503 	}
504 
505 	/* Loop through all messages */
506 	for (i = 0; i < num; i++) {
507 		pmsg = &msgs[i];
508 
509 		/* Send restart for subsequent messages */
510 		if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) {
511 			rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
512 			if (rc < 0) {
513 				printf("restart cmd failed rc = %d\n", rc);
514 				goto xfer_send_stop;
515 			}
516 		}
517 
518 		/* Send slave address */
519 		if (!(pmsg->flags & I2C_M_NOSTART)) {
520 			rc = bcm_kona_i2c_do_addr(dev, pmsg);
521 			if (rc < 0) {
522 				debug("NAK from addr %2.2x msg#%d rc = %d\n",
523 				      pmsg->addr, i, rc);
524 				goto xfer_send_stop;
525 			}
526 		}
527 
528 		/* Perform data transfer */
529 		if (pmsg->flags & I2C_M_RD) {
530 			rc = bcm_kona_i2c_read_fifo(dev, pmsg);
531 			if (rc < 0) {
532 				printf("read failure\n");
533 				goto xfer_send_stop;
534 			}
535 		} else {
536 			rc = bcm_kona_i2c_write_fifo(dev, pmsg);
537 			if (rc < 0) {
538 				printf("write failure");
539 				goto xfer_send_stop;
540 			}
541 		}
542 	}
543 
544 	rc = num;
545 
546 xfer_send_stop:
547 	/* Send a STOP command */
548 	bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
549 
550 xfer_disable_pad:
551 	/* Disable pad output */
552 	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
553 
554 	/* Stop internal clock */
555 	bcm_kona_i2c_disable_clock(dev);
556 
557 	return rc;
558 }
559 
560 static uint bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev,
561 					  uint speed)
562 {
563 	switch (speed) {
564 	case 100000:
565 		dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
566 		break;
567 	case 400000:
568 		dev->std_cfg = &std_cfg_table[BCM_SPD_400K];
569 		break;
570 	case 1000000:
571 		dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ];
572 		break;
573 	default:
574 		printf("%d hz bus speed not supported\n", speed);
575 		return -EINVAL;
576 	}
577 	dev->speed = speed;
578 	return 0;
579 }
580 
581 static void bcm_kona_i2c_init(struct bcm_kona_i2c_dev *dev)
582 {
583 	/* Parse bus speed */
584 	bcm_kona_i2c_assign_bus_speed(dev, dev->speed);
585 
586 	/* Enable internal clocks */
587 	bcm_kona_i2c_enable_clock(dev);
588 
589 	/* Configure internal dividers */
590 	bcm_kona_i2c_config_timing(dev);
591 
592 	/* Disable timeout */
593 	writel(0, dev->base + TOUT_OFFSET);
594 
595 	/* Enable autosense */
596 	bcm_kona_i2c_enable_autosense(dev);
597 
598 	/* Enable TX FIFO */
599 	writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
600 	       dev->base + TXFCR_OFFSET);
601 
602 	/* Mask all interrupts */
603 	writel(0, dev->base + IER_OFFSET);
604 
605 	/* Clear all pending interrupts */
606 	writel(ISR_CMDBUSY_MASK |
607 	       ISR_READ_COMPLETE_MASK |
608 	       ISR_SES_DONE_MASK |
609 	       ISR_ERR_MASK |
610 	       ISR_TXFIFOEMPTY_MASK | ISR_NOACK_MASK, dev->base + ISR_OFFSET);
611 
612 	/* Enable the controller but leave it idle */
613 	bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
614 
615 	/* Disable pad output */
616 	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
617 }
618 
619 /*
620  * uboot layer
621  */
622 struct bcm_kona_i2c_dev *kona_get_dev(struct i2c_adapter *adap)
623 {
624 	return &g_i2c_devs[adap->hwadapnr];
625 }
626 
627 static void kona_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
628 {
629 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
630 
631 	if (clk_bsc_enable(dev->base))
632 		return;
633 
634 	bcm_kona_i2c_init(dev);
635 }
636 
637 static int kona_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
638 			 int alen, uchar *buffer, int len)
639 {
640 	/* msg[0] writes the addr, msg[1] reads the data */
641 	struct kona_i2c_msg msg[2];
642 	unsigned char msgbuf0[64];
643 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
644 
645 	msg[0].addr = chip;
646 	msg[0].flags = 0;
647 	msg[0].len = 1;
648 	msg[0].buf = msgbuf0;	/* msgbuf0 contains incrementing reg addr */
649 
650 	msg[1].addr = chip;
651 	msg[1].flags = I2C_M_RD;
652 	/* msg[1].buf dest ptr increments each read */
653 
654 	msgbuf0[0] = (unsigned char)addr;
655 	msg[1].buf = buffer;
656 	msg[1].len = len;
657 	if (bcm_kona_i2c_xfer(dev, msg, 2) < 0) {
658 		/* Sending 2 i2c messages */
659 		kona_i2c_init(adap, adap->speed, adap->slaveaddr);
660 		debug("I2C read: I/O error\n");
661 		return -EIO;
662 	}
663 	return 0;
664 }
665 
666 static int kona_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
667 			  int alen, uchar *buffer, int len)
668 {
669 	struct kona_i2c_msg msg[1];
670 	unsigned char msgbuf0[64];
671 	unsigned int i;
672 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
673 
674 	msg[0].addr = chip;
675 	msg[0].flags = 0;
676 	msg[0].len = 2;		/* addr byte plus data */
677 	msg[0].buf = msgbuf0;
678 
679 	for (i = 0; i < len; i++) {
680 		msgbuf0[0] = addr++;
681 		msgbuf0[1] = buffer[i];
682 		if (bcm_kona_i2c_xfer(dev, msg, 1) < 0) {
683 			kona_i2c_init(adap, adap->speed, adap->slaveaddr);
684 			debug("I2C write: I/O error\n");
685 			return -EIO;
686 		}
687 	}
688 	return 0;
689 }
690 
691 static int kona_i2c_probe(struct i2c_adapter *adap, uchar chip)
692 {
693 	uchar tmp;
694 
695 	/*
696 	 * read addr 0x0 of the given chip.
697 	 */
698 	return kona_i2c_read(adap, chip, 0x0, 1, &tmp, 1);
699 }
700 
701 static uint kona_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
702 {
703 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
704 	return bcm_kona_i2c_assign_bus_speed(dev, speed);
705 }
706 
707 /*
708  * Register kona i2c adapters. Keep the order below so
709  * that the bus number matches the adapter number.
710  */
711 #define DEF_ADAPTER(num) \
712 U_BOOT_I2C_ADAP_COMPLETE(kona##num, kona_i2c_init, kona_i2c_probe, \
713 			 kona_i2c_read, kona_i2c_write, \
714 			 kona_i2c_set_bus_speed, DEF_SPD, 0x00, num)
715 
716 #ifdef CONFIG_SYS_I2C_BASE0
717 	DEF_ADAPTER(0)
718 #endif
719 #ifdef CONFIG_SYS_I2C_BASE1
720 	DEF_ADAPTER(1)
721 #endif
722 #ifdef CONFIG_SYS_I2C_BASE2
723 	DEF_ADAPTER(2)
724 #endif
725 #ifdef CONFIG_SYS_I2C_BASE3
726 	DEF_ADAPTER(3)
727 #endif
728 #ifdef CONFIG_SYS_I2C_BASE4
729 	DEF_ADAPTER(4)
730 #endif
731 #ifdef CONFIG_SYS_I2C_BASE5
732 	DEF_ADAPTER(5)
733 #endif
734