1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2013 Broadcom Corporation.
4  *
5  * NOTE: This driver should be converted to driver model before June 2017.
6  * Please see doc/driver-model/i2c-howto.rst for instructions.
7  */
8 
9 #include <common.h>
10 #include <log.h>
11 #include <asm/io.h>
12 #include <linux/delay.h>
13 #include <linux/errno.h>
14 #include <asm/arch/sysmap.h>
15 #include <asm/kona-common/clk.h>
16 #include <i2c.h>
17 
18 /* Hardware register offsets and field defintions */
19 #define CS_OFFSET				0x00000020
20 #define CS_ACK_SHIFT				3
21 #define CS_ACK_MASK				0x00000008
22 #define CS_ACK_CMD_GEN_START			0x00000000
23 #define CS_ACK_CMD_GEN_RESTART			0x00000001
24 #define CS_CMD_SHIFT				1
25 #define CS_CMD_CMD_NO_ACTION			0x00000000
26 #define CS_CMD_CMD_START_RESTART		0x00000001
27 #define CS_CMD_CMD_STOP				0x00000002
28 #define CS_EN_SHIFT				0
29 #define CS_EN_CMD_ENABLE_BSC			0x00000001
30 
31 #define TIM_OFFSET				0x00000024
32 #define TIM_PRESCALE_SHIFT			6
33 #define TIM_P_SHIFT				3
34 #define TIM_NO_DIV_SHIFT			2
35 #define TIM_DIV_SHIFT				0
36 
37 #define DAT_OFFSET				0x00000028
38 
39 #define TOUT_OFFSET				0x0000002c
40 
41 #define TXFCR_OFFSET				0x0000003c
42 #define TXFCR_FIFO_FLUSH_MASK			0x00000080
43 #define TXFCR_FIFO_EN_MASK			0x00000040
44 
45 #define IER_OFFSET				0x00000044
46 #define IER_READ_COMPLETE_INT_MASK		0x00000010
47 #define IER_I2C_INT_EN_MASK			0x00000008
48 #define IER_FIFO_INT_EN_MASK			0x00000002
49 #define IER_NOACK_EN_MASK			0x00000001
50 
51 #define ISR_OFFSET				0x00000048
52 #define ISR_RESERVED_MASK			0xffffff60
53 #define ISR_CMDBUSY_MASK			0x00000080
54 #define ISR_READ_COMPLETE_MASK			0x00000010
55 #define ISR_SES_DONE_MASK			0x00000008
56 #define ISR_ERR_MASK				0x00000004
57 #define ISR_TXFIFOEMPTY_MASK			0x00000002
58 #define ISR_NOACK_MASK				0x00000001
59 
60 #define CLKEN_OFFSET				0x0000004c
61 #define CLKEN_AUTOSENSE_OFF_MASK		0x00000080
62 #define CLKEN_M_SHIFT				4
63 #define CLKEN_N_SHIFT				1
64 #define CLKEN_CLKEN_MASK			0x00000001
65 
66 #define FIFO_STATUS_OFFSET			0x00000054
67 #define FIFO_STATUS_RXFIFO_EMPTY_MASK		0x00000004
68 #define FIFO_STATUS_TXFIFO_EMPTY_MASK		0x00000010
69 
70 #define HSTIM_OFFSET				0x00000058
71 #define HSTIM_HS_MODE_MASK			0x00008000
72 #define HSTIM_HS_HOLD_SHIFT			10
73 #define HSTIM_HS_HIGH_PHASE_SHIFT		5
74 #define HSTIM_HS_SETUP_SHIFT			0
75 
76 #define PADCTL_OFFSET				0x0000005c
77 #define PADCTL_PAD_OUT_EN_MASK			0x00000004
78 
79 #define RXFCR_OFFSET				0x00000068
80 #define RXFCR_NACK_EN_SHIFT			7
81 #define RXFCR_READ_COUNT_SHIFT			0
82 #define RXFIFORDOUT_OFFSET			0x0000006c
83 
84 /* Locally used constants */
85 #define MAX_RX_FIFO_SIZE		64U	/* bytes */
86 #define MAX_TX_FIFO_SIZE		64U	/* bytes */
87 
88 #define I2C_TIMEOUT			100000	/* usecs */
89 
90 #define WAIT_INT_CHK			100	/* usecs */
91 #if I2C_TIMEOUT % WAIT_INT_CHK
92 #error I2C_TIMEOUT must be a multiple of WAIT_INT_CHK
93 #endif
94 
95 /* Operations that can be commanded to the controller */
96 enum bcm_kona_cmd_t {
97 	BCM_CMD_NOACTION = 0,
98 	BCM_CMD_START,
99 	BCM_CMD_RESTART,
100 	BCM_CMD_STOP,
101 };
102 
103 /* Internal divider settings for standard mode, fast mode and fast mode plus */
104 struct bus_speed_cfg {
105 	uint8_t time_m;		/* Number of cycles for setup time */
106 	uint8_t time_n;		/* Number of cycles for hold time */
107 	uint8_t prescale;	/* Prescale divider */
108 	uint8_t time_p;		/* Timing coefficient */
109 	uint8_t no_div;		/* Disable clock divider */
110 	uint8_t time_div;	/* Post-prescale divider */
111 };
112 
113 static const struct bus_speed_cfg std_cfg_table[] = {
114 	[IC_SPEED_MODE_STANDARD] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
115 	[IC_SPEED_MODE_FAST] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
116 	[IC_SPEED_MODE_FAST_PLUS] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
117 };
118 
119 struct bcm_kona_i2c_dev {
120 	void *base;
121 	uint speed;
122 	const struct bus_speed_cfg *std_cfg;
123 };
124 
125 /* Keep these two defines in sync */
126 #define DEF_SPD I2C_SPEED_STANDARD_RATE
127 #define DEF_SPD_ENUM IC_SPEED_MODE_STANDARD
128 
129 #define DEF_DEVICE(num) \
130 {(void *)CONFIG_SYS_I2C_BASE##num, DEF_SPD, &std_cfg_table[DEF_SPD_ENUM]}
131 
132 static struct bcm_kona_i2c_dev g_i2c_devs[CONFIG_SYS_MAX_I2C_BUS] = {
133 #ifdef CONFIG_SYS_I2C_BASE0
134 	DEF_DEVICE(0),
135 #endif
136 #ifdef CONFIG_SYS_I2C_BASE1
137 	DEF_DEVICE(1),
138 #endif
139 #ifdef CONFIG_SYS_I2C_BASE2
140 	DEF_DEVICE(2),
141 #endif
142 #ifdef CONFIG_SYS_I2C_BASE3
143 	DEF_DEVICE(3),
144 #endif
145 #ifdef CONFIG_SYS_I2C_BASE4
146 	DEF_DEVICE(4),
147 #endif
148 #ifdef CONFIG_SYS_I2C_BASE5
149 	DEF_DEVICE(5),
150 #endif
151 };
152 
153 #define I2C_M_TEN	0x0010	/* ten bit address */
154 #define I2C_M_RD	0x0001	/* read data */
155 #define I2C_M_NOSTART	0x4000	/* no restart between msgs */
156 
157 struct kona_i2c_msg {
158 	uint16_t addr;
159 	uint16_t flags;
160 	uint16_t len;
161 	uint8_t *buf;
162 };
163 
bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev * dev,enum bcm_kona_cmd_t cmd)164 static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev,
165 					  enum bcm_kona_cmd_t cmd)
166 {
167 	debug("%s, %d\n", __func__, cmd);
168 
169 	switch (cmd) {
170 	case BCM_CMD_NOACTION:
171 		writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) |
172 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
173 		       dev->base + CS_OFFSET);
174 		break;
175 
176 	case BCM_CMD_START:
177 		writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) |
178 		       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
179 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
180 		       dev->base + CS_OFFSET);
181 		break;
182 
183 	case BCM_CMD_RESTART:
184 		writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) |
185 		       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
186 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
187 		       dev->base + CS_OFFSET);
188 		break;
189 
190 	case BCM_CMD_STOP:
191 		writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) |
192 		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
193 		       dev->base + CS_OFFSET);
194 		break;
195 
196 	default:
197 		printf("Unknown command %d\n", cmd);
198 	}
199 }
200 
bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev * dev)201 static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev)
202 {
203 	writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK,
204 	       dev->base + CLKEN_OFFSET);
205 }
206 
bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev * dev)207 static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev)
208 {
209 	writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK,
210 	       dev->base + CLKEN_OFFSET);
211 }
212 
213 /* Wait until at least one of the mask bit(s) are set */
wait_for_int_timeout(struct bcm_kona_i2c_dev * dev,unsigned long time_left,uint32_t mask)214 static unsigned long wait_for_int_timeout(struct bcm_kona_i2c_dev *dev,
215 					  unsigned long time_left,
216 					  uint32_t mask)
217 {
218 	uint32_t status;
219 
220 	while (time_left) {
221 		status = readl(dev->base + ISR_OFFSET);
222 
223 		if ((status & ~ISR_RESERVED_MASK) == 0) {
224 			debug("Bogus I2C interrupt 0x%x\n", status);
225 			continue;
226 		}
227 
228 		/* Must flush the TX FIFO when NAK detected */
229 		if (status & ISR_NOACK_MASK)
230 			writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
231 			       dev->base + TXFCR_OFFSET);
232 
233 		writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET);
234 
235 		if (status & mask) {
236 			/* We are done since one of the mask bits are set */
237 			return time_left;
238 		}
239 		udelay(WAIT_INT_CHK);
240 		time_left -= WAIT_INT_CHK;
241 	}
242 	return 0;
243 }
244 
245 /* Send command to I2C bus */
bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev * dev,enum bcm_kona_cmd_t cmd)246 static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev,
247 				 enum bcm_kona_cmd_t cmd)
248 {
249 	int rc = 0;
250 	unsigned long time_left = I2C_TIMEOUT;
251 
252 	/* Send the command */
253 	bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd);
254 
255 	/* Wait for transaction to finish or timeout */
256 	time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
257 
258 	if (!time_left) {
259 		printf("controller timed out\n");
260 		rc = -ETIMEDOUT;
261 	}
262 
263 	/* Clear command */
264 	bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
265 
266 	return rc;
267 }
268 
269 /* Read a single RX FIFO worth of data from the i2c bus */
bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev * dev,uint8_t * buf,unsigned int len,unsigned int last_byte_nak)270 static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev,
271 					 uint8_t *buf, unsigned int len,
272 					 unsigned int last_byte_nak)
273 {
274 	unsigned long time_left = I2C_TIMEOUT;
275 
276 	/* Start the RX FIFO */
277 	writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) |
278 	       (len << RXFCR_READ_COUNT_SHIFT), dev->base + RXFCR_OFFSET);
279 
280 	/* Wait for FIFO read to complete */
281 	time_left =
282 	    wait_for_int_timeout(dev, time_left, IER_READ_COMPLETE_INT_MASK);
283 
284 	if (!time_left) {
285 		printf("RX FIFO time out\n");
286 		return -EREMOTEIO;
287 	}
288 
289 	/* Read data from FIFO */
290 	for (; len > 0; len--, buf++)
291 		*buf = readl(dev->base + RXFIFORDOUT_OFFSET);
292 
293 	return 0;
294 }
295 
296 /* Read any amount of data using the RX FIFO from the i2c bus */
bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev * dev,struct kona_i2c_msg * msg)297 static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
298 				  struct kona_i2c_msg *msg)
299 {
300 	unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
301 	unsigned int last_byte_nak = 0;
302 	unsigned int bytes_read = 0;
303 	int rc;
304 
305 	uint8_t *tmp_buf = msg->buf;
306 
307 	while (bytes_read < msg->len) {
308 		if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) {
309 			last_byte_nak = 1;	/* NAK last byte of transfer */
310 			bytes_to_read = msg->len - bytes_read;
311 		}
312 
313 		rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read,
314 						   last_byte_nak);
315 		if (rc < 0)
316 			return -EREMOTEIO;
317 
318 		bytes_read += bytes_to_read;
319 		tmp_buf += bytes_to_read;
320 	}
321 
322 	return 0;
323 }
324 
325 /* Write a single byte of data to the i2c bus */
bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev * dev,uint8_t data,unsigned int nak_expected)326 static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data,
327 				   unsigned int nak_expected)
328 {
329 	unsigned long time_left = I2C_TIMEOUT;
330 	unsigned int nak_received;
331 
332 	/* Clear pending session done interrupt */
333 	writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET);
334 
335 	/* Send one byte of data */
336 	writel(data, dev->base + DAT_OFFSET);
337 
338 	time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
339 
340 	if (!time_left) {
341 		debug("controller timed out\n");
342 		return -ETIMEDOUT;
343 	}
344 
345 	nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0;
346 
347 	if (nak_received ^ nak_expected) {
348 		debug("unexpected NAK/ACK\n");
349 		return -EREMOTEIO;
350 	}
351 
352 	return 0;
353 }
354 
355 /* Write a single TX FIFO worth of data to the i2c bus */
bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev * dev,uint8_t * buf,unsigned int len)356 static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev,
357 					  uint8_t *buf, unsigned int len)
358 {
359 	int k;
360 	unsigned long time_left = I2C_TIMEOUT;
361 	unsigned int fifo_status;
362 
363 	/* Write data into FIFO */
364 	for (k = 0; k < len; k++)
365 		writel(buf[k], (dev->base + DAT_OFFSET));
366 
367 	/* Wait for FIFO to empty */
368 	do {
369 		time_left =
370 		    wait_for_int_timeout(dev, time_left,
371 					 (IER_FIFO_INT_EN_MASK |
372 					  IER_NOACK_EN_MASK));
373 		fifo_status = readl(dev->base + FIFO_STATUS_OFFSET);
374 	} while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK));
375 
376 	/* Check if there was a NAK */
377 	if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) {
378 		printf("unexpected NAK\n");
379 		return -EREMOTEIO;
380 	}
381 
382 	/* Check if a timeout occurred */
383 	if (!time_left) {
384 		printf("completion timed out\n");
385 		return -EREMOTEIO;
386 	}
387 
388 	return 0;
389 }
390 
391 /* Write any amount of data using TX FIFO to the i2c bus */
bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev * dev,struct kona_i2c_msg * msg)392 static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
393 				   struct kona_i2c_msg *msg)
394 {
395 	unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
396 	unsigned int bytes_written = 0;
397 	int rc;
398 
399 	uint8_t *tmp_buf = msg->buf;
400 
401 	while (bytes_written < msg->len) {
402 		if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE)
403 			bytes_to_write = msg->len - bytes_written;
404 
405 		rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf,
406 						    bytes_to_write);
407 		if (rc < 0)
408 			return -EREMOTEIO;
409 
410 		bytes_written += bytes_to_write;
411 		tmp_buf += bytes_to_write;
412 	}
413 
414 	return 0;
415 }
416 
417 /* Send i2c address */
bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev * dev,struct kona_i2c_msg * msg)418 static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev,
419 				struct kona_i2c_msg *msg)
420 {
421 	unsigned char addr;
422 
423 	if (msg->flags & I2C_M_TEN) {
424 		/* First byte is 11110XX0 where XX is upper 2 bits */
425 		addr = 0xf0 | ((msg->addr & 0x300) >> 7);
426 		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
427 			return -EREMOTEIO;
428 
429 		/* Second byte is the remaining 8 bits */
430 		addr = msg->addr & 0xff;
431 		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
432 			return -EREMOTEIO;
433 
434 		if (msg->flags & I2C_M_RD) {
435 			/* For read, send restart command */
436 			if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0)
437 				return -EREMOTEIO;
438 
439 			/* Then re-send the first byte with the read bit set */
440 			addr = 0xf0 | ((msg->addr & 0x300) >> 7) | 0x01;
441 			if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
442 				return -EREMOTEIO;
443 		}
444 	} else {
445 		addr = msg->addr << 1;
446 
447 		if (msg->flags & I2C_M_RD)
448 			addr |= 1;
449 
450 		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
451 			return -EREMOTEIO;
452 	}
453 
454 	return 0;
455 }
456 
bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev * dev)457 static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev)
458 {
459 	writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK,
460 	       dev->base + CLKEN_OFFSET);
461 }
462 
bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev * dev)463 static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
464 {
465 	writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK,
466 	       dev->base + HSTIM_OFFSET);
467 
468 	writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) |
469 	       (dev->std_cfg->time_p << TIM_P_SHIFT) |
470 	       (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) |
471 	       (dev->std_cfg->time_div << TIM_DIV_SHIFT),
472 	       dev->base + TIM_OFFSET);
473 
474 	writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) |
475 	       (dev->std_cfg->time_n << CLKEN_N_SHIFT) |
476 	       CLKEN_CLKEN_MASK, dev->base + CLKEN_OFFSET);
477 }
478 
479 /* Master transfer function */
bcm_kona_i2c_xfer(struct bcm_kona_i2c_dev * dev,struct kona_i2c_msg msgs[],int num)480 static int bcm_kona_i2c_xfer(struct bcm_kona_i2c_dev *dev,
481 			     struct kona_i2c_msg msgs[], int num)
482 {
483 	struct kona_i2c_msg *pmsg;
484 	int rc = 0;
485 	int i;
486 
487 	/* Enable pad output */
488 	writel(0, dev->base + PADCTL_OFFSET);
489 
490 	/* Enable internal clocks */
491 	bcm_kona_i2c_enable_clock(dev);
492 
493 	/* Send start command */
494 	rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START);
495 	if (rc < 0) {
496 		printf("Start command failed rc = %d\n", rc);
497 		goto xfer_disable_pad;
498 	}
499 
500 	/* Loop through all messages */
501 	for (i = 0; i < num; i++) {
502 		pmsg = &msgs[i];
503 
504 		/* Send restart for subsequent messages */
505 		if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) {
506 			rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
507 			if (rc < 0) {
508 				printf("restart cmd failed rc = %d\n", rc);
509 				goto xfer_send_stop;
510 			}
511 		}
512 
513 		/* Send slave address */
514 		if (!(pmsg->flags & I2C_M_NOSTART)) {
515 			rc = bcm_kona_i2c_do_addr(dev, pmsg);
516 			if (rc < 0) {
517 				debug("NAK from addr %2.2x msg#%d rc = %d\n",
518 				      pmsg->addr, i, rc);
519 				goto xfer_send_stop;
520 			}
521 		}
522 
523 		/* Perform data transfer */
524 		if (pmsg->flags & I2C_M_RD) {
525 			rc = bcm_kona_i2c_read_fifo(dev, pmsg);
526 			if (rc < 0) {
527 				printf("read failure\n");
528 				goto xfer_send_stop;
529 			}
530 		} else {
531 			rc = bcm_kona_i2c_write_fifo(dev, pmsg);
532 			if (rc < 0) {
533 				printf("write failure");
534 				goto xfer_send_stop;
535 			}
536 		}
537 	}
538 
539 	rc = num;
540 
541 xfer_send_stop:
542 	/* Send a STOP command */
543 	bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
544 
545 xfer_disable_pad:
546 	/* Disable pad output */
547 	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
548 
549 	/* Stop internal clock */
550 	bcm_kona_i2c_disable_clock(dev);
551 
552 	return rc;
553 }
554 
bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev * dev,uint speed)555 static uint bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev,
556 					  uint speed)
557 {
558 	switch (speed) {
559 	case I2C_SPEED_STANDARD_RATE:
560 		dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_STANDARD];
561 		break;
562 	case I2C_SPEED_FAST_RATE:
563 		dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_FAST];
564 		break;
565 	case I2C_SPEED_FAST_PLUS_RATE:
566 		dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_FAST_PLUS];
567 		break;
568 	default:
569 		printf("%d hz bus speed not supported\n", speed);
570 		return -EINVAL;
571 	}
572 	dev->speed = speed;
573 	return 0;
574 }
575 
bcm_kona_i2c_init(struct bcm_kona_i2c_dev * dev)576 static void bcm_kona_i2c_init(struct bcm_kona_i2c_dev *dev)
577 {
578 	/* Parse bus speed */
579 	bcm_kona_i2c_assign_bus_speed(dev, dev->speed);
580 
581 	/* Enable internal clocks */
582 	bcm_kona_i2c_enable_clock(dev);
583 
584 	/* Configure internal dividers */
585 	bcm_kona_i2c_config_timing(dev);
586 
587 	/* Disable timeout */
588 	writel(0, dev->base + TOUT_OFFSET);
589 
590 	/* Enable autosense */
591 	bcm_kona_i2c_enable_autosense(dev);
592 
593 	/* Enable TX FIFO */
594 	writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
595 	       dev->base + TXFCR_OFFSET);
596 
597 	/* Mask all interrupts */
598 	writel(0, dev->base + IER_OFFSET);
599 
600 	/* Clear all pending interrupts */
601 	writel(ISR_CMDBUSY_MASK |
602 	       ISR_READ_COMPLETE_MASK |
603 	       ISR_SES_DONE_MASK |
604 	       ISR_ERR_MASK |
605 	       ISR_TXFIFOEMPTY_MASK | ISR_NOACK_MASK, dev->base + ISR_OFFSET);
606 
607 	/* Enable the controller but leave it idle */
608 	bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
609 
610 	/* Disable pad output */
611 	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
612 }
613 
614 /*
615  * uboot layer
616  */
kona_get_dev(struct i2c_adapter * adap)617 struct bcm_kona_i2c_dev *kona_get_dev(struct i2c_adapter *adap)
618 {
619 	return &g_i2c_devs[adap->hwadapnr];
620 }
621 
kona_i2c_init(struct i2c_adapter * adap,int speed,int slaveaddr)622 static void kona_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
623 {
624 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
625 
626 	if (clk_bsc_enable(dev->base))
627 		return;
628 
629 	bcm_kona_i2c_init(dev);
630 }
631 
kona_i2c_read(struct i2c_adapter * adap,uchar chip,uint addr,int alen,uchar * buffer,int len)632 static int kona_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
633 			 int alen, uchar *buffer, int len)
634 {
635 	/* msg[0] writes the addr, msg[1] reads the data */
636 	struct kona_i2c_msg msg[2];
637 	unsigned char msgbuf0[64];
638 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
639 
640 	msg[0].addr = chip;
641 	msg[0].flags = 0;
642 	msg[0].len = 1;
643 	msg[0].buf = msgbuf0;	/* msgbuf0 contains incrementing reg addr */
644 
645 	msg[1].addr = chip;
646 	msg[1].flags = I2C_M_RD;
647 	/* msg[1].buf dest ptr increments each read */
648 
649 	msgbuf0[0] = (unsigned char)addr;
650 	msg[1].buf = buffer;
651 	msg[1].len = len;
652 	if (bcm_kona_i2c_xfer(dev, msg, 2) < 0) {
653 		/* Sending 2 i2c messages */
654 		kona_i2c_init(adap, adap->speed, adap->slaveaddr);
655 		debug("I2C read: I/O error\n");
656 		return -EIO;
657 	}
658 	return 0;
659 }
660 
kona_i2c_write(struct i2c_adapter * adap,uchar chip,uint addr,int alen,uchar * buffer,int len)661 static int kona_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
662 			  int alen, uchar *buffer, int len)
663 {
664 	struct kona_i2c_msg msg[1];
665 	unsigned char msgbuf0[64];
666 	unsigned int i;
667 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
668 
669 	msg[0].addr = chip;
670 	msg[0].flags = 0;
671 	msg[0].len = 2;		/* addr byte plus data */
672 	msg[0].buf = msgbuf0;
673 
674 	for (i = 0; i < len; i++) {
675 		msgbuf0[0] = addr++;
676 		msgbuf0[1] = buffer[i];
677 		if (bcm_kona_i2c_xfer(dev, msg, 1) < 0) {
678 			kona_i2c_init(adap, adap->speed, adap->slaveaddr);
679 			debug("I2C write: I/O error\n");
680 			return -EIO;
681 		}
682 	}
683 	return 0;
684 }
685 
kona_i2c_probe(struct i2c_adapter * adap,uchar chip)686 static int kona_i2c_probe(struct i2c_adapter *adap, uchar chip)
687 {
688 	uchar tmp;
689 
690 	/*
691 	 * read addr 0x0 of the given chip.
692 	 */
693 	return kona_i2c_read(adap, chip, 0x0, 1, &tmp, 1);
694 }
695 
kona_i2c_set_bus_speed(struct i2c_adapter * adap,uint speed)696 static uint kona_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
697 {
698 	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
699 	return bcm_kona_i2c_assign_bus_speed(dev, speed);
700 }
701 
702 /*
703  * Register kona i2c adapters. Keep the order below so
704  * that the bus number matches the adapter number.
705  */
706 #define DEF_ADAPTER(num) \
707 U_BOOT_I2C_ADAP_COMPLETE(kona##num, kona_i2c_init, kona_i2c_probe, \
708 			 kona_i2c_read, kona_i2c_write, \
709 			 kona_i2c_set_bus_speed, DEF_SPD, 0x00, num)
710 
711 #ifdef CONFIG_SYS_I2C_BASE0
712 	DEF_ADAPTER(0)
713 #endif
714 #ifdef CONFIG_SYS_I2C_BASE1
715 	DEF_ADAPTER(1)
716 #endif
717 #ifdef CONFIG_SYS_I2C_BASE2
718 	DEF_ADAPTER(2)
719 #endif
720 #ifdef CONFIG_SYS_I2C_BASE3
721 	DEF_ADAPTER(3)
722 #endif
723 #ifdef CONFIG_SYS_I2C_BASE4
724 	DEF_ADAPTER(4)
725 #endif
726 #ifdef CONFIG_SYS_I2C_BASE5
727 	DEF_ADAPTER(5)
728 #endif
729