1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2018 Broadcom
4  *
5  */
6 
7 #include <asm/global_data.h>
8 #include <asm/io.h>
9 #include <common.h>
10 #include <config.h>
11 #include <dm.h>
12 #include "errno.h"
13 #include <i2c.h>
14 #include "iproc_i2c.h"
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 struct iproc_i2c_regs {
19 	u32 cfg_reg;
20 	u32 timg_cfg;
21 	u32 addr_reg;
22 	u32 mstr_fifo_ctrl;
23 	u32 slv_fifo_ctrl;
24 	u32 bitbng_ctrl;
25 	u32 blnks[6]; /* Not to be used */
26 	u32 mstr_cmd;
27 	u32 slv_cmd;
28 	u32 evt_en;
29 	u32 evt_sts;
30 	u32 mstr_datawr;
31 	u32 mstr_datard;
32 	u32 slv_datawr;
33 	u32 slv_datard;
34 };
35 
36 struct iproc_i2c {
37 	struct iproc_i2c_regs __iomem *base; /* register base */
38 	int bus_speed;
39 	int i2c_init_done;
40 };
41 
42 /* Function to read a value from specified register. */
iproc_i2c_reg_read(u32 * reg_addr)43 static unsigned int iproc_i2c_reg_read(u32 *reg_addr)
44 {
45 	unsigned int val;
46 
47 	val = readl((void *)(reg_addr));
48 	return cpu_to_le32(val);
49 }
50 
51 /* Function to write a value ('val') in to a specified register. */
iproc_i2c_reg_write(u32 * reg_addr,unsigned int val)52 static int iproc_i2c_reg_write(u32 *reg_addr, unsigned int val)
53 {
54 	val = cpu_to_le32(val);
55 	writel(val, (void *)(reg_addr));
56 	return  0;
57 }
58 
59 #if defined(DEBUG)
iproc_dump_i2c_regs(struct iproc_i2c * bus_prvdata)60 static int iproc_dump_i2c_regs(struct iproc_i2c *bus_prvdata)
61 {
62 	struct iproc_i2c_regs *base = bus_prvdata->base;
63 	unsigned int regval;
64 
65 	debug("\n----------------------------------------------\n");
66 	debug("%s: Dumping SMBus registers...\n", __func__);
67 
68 	regval = iproc_i2c_reg_read(&base->cfg_reg);
69 	debug("CCB_SMB_CFG_REG=0x%08X\n", regval);
70 
71 	regval = iproc_i2c_reg_read(&base->timg_cfg);
72 	debug("CCB_SMB_TIMGCFG_REG=0x%08X\n", regval);
73 
74 	regval = iproc_i2c_reg_read(&base->addr_reg);
75 	debug("CCB_SMB_ADDR_REG=0x%08X\n", regval);
76 
77 	regval = iproc_i2c_reg_read(&base->mstr_fifo_ctrl);
78 	debug("CCB_SMB_MSTRFIFOCTL_REG=0x%08X\n", regval);
79 
80 	regval = iproc_i2c_reg_read(&base->slv_fifo_ctrl);
81 	debug("CCB_SMB_SLVFIFOCTL_REG=0x%08X\n", regval);
82 
83 	regval = iproc_i2c_reg_read(&base->bitbng_ctrl);
84 	debug("CCB_SMB_BITBANGCTL_REG=0x%08X\n", regval);
85 
86 	regval = iproc_i2c_reg_read(&base->mstr_cmd);
87 	debug("CCB_SMB_MSTRCMD_REG=0x%08X\n", regval);
88 
89 	regval = iproc_i2c_reg_read(&base->slv_cmd);
90 	debug("CCB_SMB_SLVCMD_REG=0x%08X\n", regval);
91 
92 	regval = iproc_i2c_reg_read(&base->evt_en);
93 	debug("CCB_SMB_EVTEN_REG=0x%08X\n", regval);
94 
95 	regval = iproc_i2c_reg_read(&base->evt_sts);
96 	debug("CCB_SMB_EVTSTS_REG=0x%08X\n", regval);
97 
98 	regval = iproc_i2c_reg_read(&base->mstr_datawr);
99 	debug("CCB_SMB_MSTRDATAWR_REG=0x%08X\n", regval);
100 
101 	regval = iproc_i2c_reg_read(&base->mstr_datard);
102 	debug("CCB_SMB_MSTRDATARD_REG=0x%08X\n", regval);
103 
104 	regval = iproc_i2c_reg_read(&base->slv_datawr);
105 	debug("CCB_SMB_SLVDATAWR_REG=0x%08X\n", regval);
106 
107 	regval = iproc_i2c_reg_read(&base->slv_datard);
108 	debug("CCB_SMB_SLVDATARD_REG=0x%08X\n", regval);
109 
110 	debug("----------------------------------------------\n\n");
111 	return 0;
112 }
113 #else
iproc_dump_i2c_regs(struct iproc_i2c * bus_prvdata)114 static int iproc_dump_i2c_regs(struct iproc_i2c *bus_prvdata)
115 {
116 	return 0;
117 }
118 #endif
119 
120 /*
121  * Function to ensure that the previous transaction was completed before
122  * initiating a new transaction. It can also be used in polling mode to
123  * check status of completion of a command
124  */
iproc_i2c_startbusy_wait(struct iproc_i2c * bus_prvdata)125 static int iproc_i2c_startbusy_wait(struct iproc_i2c *bus_prvdata)
126 {
127 	struct iproc_i2c_regs *base = bus_prvdata->base;
128 	unsigned int regval;
129 
130 	regval = iproc_i2c_reg_read(&base->mstr_cmd);
131 
132 	/* Check if an operation is in progress. During probe it won't be.
133 	 * But when shutdown/remove was called we want to make sure that
134 	 * the transaction in progress completed
135 	 */
136 	if (regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) {
137 		unsigned int i = 0;
138 
139 		do {
140 			mdelay(10);
141 			i++;
142 			regval = iproc_i2c_reg_read(&base->mstr_cmd);
143 
144 			/* If start-busy bit cleared, exit the loop */
145 		} while ((regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) &&
146 			 (i < IPROC_SMB_MAX_RETRIES));
147 
148 		if (i >= IPROC_SMB_MAX_RETRIES) {
149 			pr_err("%s: START_BUSY bit didn't clear, exiting\n",
150 			       __func__);
151 			return -ETIMEDOUT;
152 		}
153 	}
154 	return 0;
155 }
156 
157 /*
158  * This function set clock frequency for SMBus block. As per hardware
159  * engineering, the clock frequency can be changed dynamically.
160  */
iproc_i2c_set_clk_freq(struct iproc_i2c * bus_prvdata)161 static int iproc_i2c_set_clk_freq(struct iproc_i2c *bus_prvdata)
162 {
163 	struct iproc_i2c_regs *base = bus_prvdata->base;
164 	unsigned int regval;
165 
166 	regval = iproc_i2c_reg_read(&base->timg_cfg);
167 
168 	switch (bus_prvdata->bus_speed) {
169 	case I2C_SPEED_STANDARD_RATE:
170 		regval &= ~CCB_SMB_TIMGCFG_MODE400_MASK;
171 		break;
172 
173 	case I2C_SPEED_FAST_RATE:
174 		regval |= CCB_SMB_TIMGCFG_MODE400_MASK;
175 		break;
176 
177 	default:
178 		return -EINVAL;
179 	}
180 
181 	iproc_i2c_reg_write(&base->timg_cfg, regval);
182 	return 0;
183 }
184 
iproc_i2c_init(struct udevice * bus)185 static int iproc_i2c_init(struct udevice *bus)
186 {
187 	struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
188 	struct iproc_i2c_regs *base = bus_prvdata->base;
189 	unsigned int regval;
190 
191 	debug("\nEntering %s\n", __func__);
192 
193 	/* Put controller in reset */
194 	regval = iproc_i2c_reg_read(&base->cfg_reg);
195 	regval |= CCB_SMB_CFG_RST_MASK;
196 	regval &= ~CCB_SMB_CFG_SMBEN_MASK;
197 	iproc_i2c_reg_write(&base->cfg_reg, regval);
198 
199 	/* Wait 100 usec as per spec */
200 	udelay(100);
201 
202 	/* bring controller out of reset */
203 	regval &= ~CCB_SMB_CFG_RST_MASK;
204 	iproc_i2c_reg_write(&base->cfg_reg, regval);
205 
206 	/* Flush Tx, Rx FIFOs. Note we are setting the Rx FIFO threshold to 0.
207 	 * May be OK since we are setting RX_EVENT and RX_FIFO_FULL interrupts
208 	 */
209 	regval = CCB_SMB_MSTRRXFIFOFLSH_MASK | CCB_SMB_MSTRTXFIFOFLSH_MASK;
210 	iproc_i2c_reg_write(&base->mstr_fifo_ctrl, regval);
211 
212 	/* Enable SMbus block. Note, we are setting MASTER_RETRY_COUNT to zero
213 	 * since there will be only one master
214 	 */
215 	regval = iproc_i2c_reg_read(&base->cfg_reg);
216 	regval |= CCB_SMB_CFG_SMBEN_MASK;
217 	iproc_i2c_reg_write(&base->cfg_reg, regval);
218 
219 	/* Set default clock frequency */
220 	iproc_i2c_set_clk_freq(bus_prvdata);
221 
222 	/* Disable intrs */
223 	iproc_i2c_reg_write(&base->evt_en, 0);
224 
225 	/* Clear intrs (W1TC) */
226 	regval = iproc_i2c_reg_read(&base->evt_sts);
227 	iproc_i2c_reg_write(&base->evt_sts, regval);
228 
229 	bus_prvdata->i2c_init_done = 1;
230 
231 	iproc_dump_i2c_regs(bus_prvdata);
232 	debug("%s: Init successful\n", __func__);
233 
234 	return 0;
235 }
236 
237 /*
238  * This function copies data to SMBus's Tx FIFO. Valid for write transactions
239  * only
240  *
241  * base_addr: Mapped address of this SMBus instance
242  * dev_addr:  SMBus (I2C) device address. We are assuming 7-bit addresses
243  *            initially
244  * info:   Data to copy in to Tx FIFO. For read commands, the size should be
245  *         set to zero by the caller
246  *
247  */
iproc_i2c_write_trans_data(struct iproc_i2c * bus_prvdata,unsigned short dev_addr,struct iproc_xact_info * info)248 static void iproc_i2c_write_trans_data(struct iproc_i2c *bus_prvdata,
249 				       unsigned short dev_addr,
250 				       struct iproc_xact_info *info)
251 {
252 	struct iproc_i2c_regs *base = bus_prvdata->base;
253 	unsigned int regval;
254 	unsigned int i;
255 	unsigned int num_data_bytes = 0;
256 
257 	debug("%s: dev_addr=0x%X cmd_valid=%d cmd=0x%02x size=%u proto=%d buf[] %x\n",
258 	      __func__, dev_addr, info->cmd_valid,
259 	      info->command, info->size, info->smb_proto, info->data[0]);
260 
261 	/* Write SMBus device address first */
262 	/* Note, we are assuming 7-bit addresses for now. For 10-bit addresses,
263 	 * we may have one more write to send the upper 3 bits of 10-bit addr
264 	 */
265 	iproc_i2c_reg_write(&base->mstr_datawr, dev_addr);
266 
267 	/* If the protocol needs command code, copy it */
268 	if (info->cmd_valid)
269 		iproc_i2c_reg_write(&base->mstr_datawr, info->command);
270 
271 	/* Depending on the SMBus protocol, we need to write additional
272 	 * transaction data in to Tx FIFO. Refer to section 5.5 of SMBus
273 	 * spec for sequence for a transaction
274 	 */
275 	switch (info->smb_proto) {
276 	case SMBUS_PROT_RECV_BYTE:
277 		/* No additional data to be written */
278 		num_data_bytes = 0;
279 		break;
280 
281 	case SMBUS_PROT_SEND_BYTE:
282 		num_data_bytes = info->size;
283 		break;
284 
285 	case SMBUS_PROT_RD_BYTE:
286 	case SMBUS_PROT_RD_WORD:
287 	case SMBUS_PROT_BLK_RD:
288 		/* Write slave address with R/W~ set (bit #0) */
289 		iproc_i2c_reg_write(&base->mstr_datawr,
290 				    dev_addr | 0x1);
291 		num_data_bytes = 0;
292 		break;
293 
294 	case SMBUS_PROT_BLK_WR_BLK_RD_PROC_CALL:
295 		iproc_i2c_reg_write(&base->mstr_datawr,
296 				    dev_addr | 0x1 |
297 				    CCB_SMB_MSTRWRSTS_MASK);
298 		num_data_bytes = 0;
299 		break;
300 
301 	case SMBUS_PROT_WR_BYTE:
302 	case SMBUS_PROT_WR_WORD:
303 		/* No additional bytes to be written.
304 		 * Data portion is written in the
305 		 * 'for' loop below
306 		 */
307 		num_data_bytes = info->size;
308 		break;
309 
310 	case SMBUS_PROT_BLK_WR:
311 		/* 3rd byte is byte count */
312 		iproc_i2c_reg_write(&base->mstr_datawr, info->size);
313 		num_data_bytes = info->size;
314 		break;
315 
316 	default:
317 		return;
318 	}
319 
320 	/* Copy actual data from caller, next. In general, for reads,
321 	 * no data is copied
322 	 */
323 	for (i = 0; num_data_bytes; --num_data_bytes, i++) {
324 		/* For the last byte, set MASTER_WR_STATUS bit */
325 		regval = (num_data_bytes == 1) ?
326 			 info->data[i] | CCB_SMB_MSTRWRSTS_MASK :
327 			 info->data[i];
328 
329 		iproc_i2c_reg_write(&base->mstr_datawr, regval);
330 	}
331 }
332 
iproc_i2c_data_send(struct iproc_i2c * bus_prvdata,unsigned short addr,struct iproc_xact_info * info)333 static int iproc_i2c_data_send(struct iproc_i2c *bus_prvdata,
334 			       unsigned short addr,
335 			       struct iproc_xact_info *info)
336 {
337 	struct iproc_i2c_regs *base = bus_prvdata->base;
338 	int rc, retry = 3;
339 	unsigned int regval;
340 
341 	/* Make sure the previous transaction completed */
342 	rc = iproc_i2c_startbusy_wait(bus_prvdata);
343 
344 	if (rc < 0) {
345 		pr_err("%s: Send: bus is busy, exiting\n", __func__);
346 		return rc;
347 	}
348 
349 	/* Write transaction bytes to Tx FIFO */
350 	iproc_i2c_write_trans_data(bus_prvdata, addr, info);
351 
352 	/* Program master command register (0x30) with protocol type and set
353 	 * start_busy_command bit to initiate the write transaction
354 	 */
355 	regval = (info->smb_proto << CCB_SMB_MSTRSMBUSPROTO_SHIFT) |
356 		 CCB_SMB_MSTRSTARTBUSYCMD_MASK;
357 
358 	iproc_i2c_reg_write(&base->mstr_cmd, regval);
359 
360 	/* Check for Master status */
361 	regval = iproc_i2c_reg_read(&base->mstr_cmd);
362 	while (regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) {
363 		mdelay(10);
364 		if (retry-- <= 0)
365 			break;
366 		regval = iproc_i2c_reg_read(&base->mstr_cmd);
367 	}
368 
369 	/* If start_busy bit cleared, check if there are any errors */
370 	if (!(regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK)) {
371 		/* start_busy bit cleared, check master_status field now */
372 		regval &= CCB_SMB_MSTRSTS_MASK;
373 		regval >>= CCB_SMB_MSTRSTS_SHIFT;
374 
375 		if (regval != MSTR_STS_XACT_SUCCESS) {
376 			/* Error We can flush Tx FIFO here */
377 			pr_err("%s: ERROR: Error in transaction %u, exiting\n",
378 			       __func__, regval);
379 			return -EREMOTEIO;
380 		}
381 	}
382 
383 	return 0;
384 }
385 
iproc_i2c_data_recv(struct iproc_i2c * bus_prvdata,unsigned short addr,struct iproc_xact_info * info,unsigned int * num_bytes_read)386 static int iproc_i2c_data_recv(struct iproc_i2c *bus_prvdata,
387 			       unsigned short addr,
388 			       struct iproc_xact_info *info,
389 			       unsigned int *num_bytes_read)
390 {
391 	struct iproc_i2c_regs *base = bus_prvdata->base;
392 	int rc, retry = 3;
393 	unsigned int regval;
394 
395 	/* Make sure the previous transaction completed */
396 	rc = iproc_i2c_startbusy_wait(bus_prvdata);
397 
398 	if (rc < 0) {
399 		pr_err("%s: Receive: Bus is busy, exiting\n", __func__);
400 		return rc;
401 	}
402 
403 	/* Program all transaction bytes into master Tx FIFO */
404 	iproc_i2c_write_trans_data(bus_prvdata, addr, info);
405 
406 	/* Program master command register (0x30) with protocol type and set
407 	 * start_busy_command bit to initiate the write transaction
408 	 */
409 	regval = (info->smb_proto << CCB_SMB_MSTRSMBUSPROTO_SHIFT) |
410 		 CCB_SMB_MSTRSTARTBUSYCMD_MASK | info->size;
411 
412 	iproc_i2c_reg_write(&base->mstr_cmd, regval);
413 
414 	/* Check for Master status */
415 	regval = iproc_i2c_reg_read(&base->mstr_cmd);
416 	while (regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) {
417 		udelay(1000);
418 		if (retry-- <= 0)
419 			break;
420 		regval = iproc_i2c_reg_read(&base->mstr_cmd);
421 	}
422 
423 	/* If start_busy bit cleared, check if there are any errors */
424 	if (!(regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK)) {
425 		/* start_busy bit cleared, check master_status field now */
426 		regval &= CCB_SMB_MSTRSTS_MASK;
427 		regval >>= CCB_SMB_MSTRSTS_SHIFT;
428 
429 		if (regval != MSTR_STS_XACT_SUCCESS) {
430 			/* We can flush Tx FIFO here */
431 			pr_err("%s: Error in transaction %d, exiting\n",
432 			       __func__, regval);
433 			return -EREMOTEIO;
434 		}
435 	}
436 
437 	/* Read received byte(s), after TX out address etc */
438 	regval = iproc_i2c_reg_read(&base->mstr_datard);
439 
440 	/* For block read, protocol (hw) returns byte count,
441 	 * as the first byte
442 	 */
443 	if (info->smb_proto == SMBUS_PROT_BLK_RD) {
444 		int i;
445 
446 		*num_bytes_read = regval & CCB_SMB_MSTRRDDATA_MASK;
447 
448 		/* Limit to reading a max of 32 bytes only; just a safeguard.
449 		 * If # bytes read is a number > 32, check transaction set up,
450 		 * and contact hw engg. Assumption: PEC is disabled
451 		 */
452 		for (i = 0;
453 		     (i < *num_bytes_read) && (i < I2C_SMBUS_BLOCK_MAX);
454 		     i++) {
455 			/* Read Rx FIFO for data bytes */
456 			regval = iproc_i2c_reg_read(&base->mstr_datard);
457 			info->data[i] = regval & CCB_SMB_MSTRRDDATA_MASK;
458 		}
459 	} else {
460 		/* 1 Byte data */
461 		*info->data = regval & CCB_SMB_MSTRRDDATA_MASK;
462 		*num_bytes_read = 1;
463 	}
464 
465 	return 0;
466 }
467 
i2c_write_byte(struct iproc_i2c * bus_prvdata,u8 devaddr,u8 regoffset,u8 value)468 static int i2c_write_byte(struct iproc_i2c *bus_prvdata,
469 			  u8 devaddr, u8 regoffset, u8 value)
470 {
471 	int rc;
472 	struct iproc_xact_info info;
473 
474 	devaddr <<= 1;
475 
476 	info.cmd_valid = 1;
477 	info.command = (unsigned char)regoffset;
478 	info.data = &value;
479 	info.size = 1;
480 	info.flags = 0;
481 	info.smb_proto = SMBUS_PROT_WR_BYTE;
482 	/* Refer to i2c_smbus_write_byte params passed. */
483 	rc = iproc_i2c_data_send(bus_prvdata, devaddr, &info);
484 
485 	if (rc < 0) {
486 		pr_err("%s: %s error accessing device 0x%X\n",
487 		       __func__, "Write", devaddr);
488 		return -EREMOTEIO;
489 	}
490 
491 	return 0;
492 }
493 
i2c_write(struct udevice * bus,uchar chip,uint regaddr,int alen,uchar * buffer,int len)494 int i2c_write(struct udevice *bus,
495 	      uchar chip, uint regaddr, int alen, uchar *buffer, int len)
496 {
497 	struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
498 	int i, data_len;
499 	u8 *data;
500 
501 	if (len > 256) {
502 		pr_err("I2C write: address out of range\n");
503 		return 1;
504 	}
505 
506 	if (len < 1) {
507 		pr_err("I2C write: Need offset addr and value\n");
508 		return 1;
509 	}
510 
511 	/* buffer contains offset addr followed by value to be written */
512 	regaddr = buffer[0];
513 	data = &buffer[1];
514 	data_len = len - 1;
515 
516 	for (i = 0; i < data_len; i++) {
517 		if (i2c_write_byte(bus_prvdata, chip, regaddr + i, data[i])) {
518 			pr_err("I2C write (%d): I/O error\n", i);
519 			iproc_i2c_init(bus);
520 			return 1;
521 		}
522 	}
523 
524 	return 0;
525 }
526 
i2c_read_byte(struct iproc_i2c * bus_prvdata,u8 devaddr,u8 regoffset,u8 * value)527 static int i2c_read_byte(struct iproc_i2c *bus_prvdata,
528 			 u8 devaddr, u8 regoffset, u8 *value)
529 {
530 	int rc;
531 	struct iproc_xact_info info;
532 	unsigned int num_bytes_read = 0;
533 
534 	devaddr <<= 1;
535 
536 	info.cmd_valid = 1;
537 	info.command = (unsigned char)regoffset;
538 	info.data = value;
539 	info.size = 1;
540 	info.flags = 0;
541 	info.smb_proto = SMBUS_PROT_RD_BYTE;
542 	/* Refer to i2c_smbus_read_byte for params passed. */
543 	rc = iproc_i2c_data_recv(bus_prvdata, devaddr, &info, &num_bytes_read);
544 
545 	if (rc < 0) {
546 		pr_err("%s: %s error accessing device 0x%X\n",
547 		       __func__, "Read", devaddr);
548 		return -EREMOTEIO;
549 	}
550 
551 	return 0;
552 }
553 
i2c_read(struct udevice * bus,uchar chip,uint addr,int alen,uchar * buffer,int len)554 int i2c_read(struct udevice *bus,
555 	     uchar chip, uint addr, int alen, uchar *buffer, int len)
556 {
557 	struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
558 	int i;
559 
560 	if (len > 256) {
561 		pr_err("I2C read: address out of range\n");
562 		return 1;
563 	}
564 
565 	for (i = 0; i < len; i++) {
566 		if (i2c_read_byte(bus_prvdata, chip, addr + i, &buffer[i])) {
567 			pr_err("I2C read: I/O error\n");
568 			iproc_i2c_init(bus);
569 			return 1;
570 		}
571 	}
572 
573 	return 0;
574 }
575 
iproc_i2c_xfer(struct udevice * bus,struct i2c_msg * msg,int nmsgs)576 static int iproc_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
577 {
578 	int ret = 0;
579 
580 	debug("%s: %d messages\n", __func__, nmsgs);
581 
582 	for (; nmsgs > 0; nmsgs--, msg++) {
583 		if (msg->flags & I2C_M_RD)
584 			ret = i2c_read(bus, msg->addr, 0, 0,
585 				       msg->buf, msg->len);
586 		else
587 			ret = i2c_write(bus, msg->addr, 0, 0,
588 					msg->buf, msg->len);
589 	}
590 
591 	return ret;
592 }
593 
iproc_i2c_probe_chip(struct udevice * bus,uint chip_addr,uint chip_flags)594 static int iproc_i2c_probe_chip(struct udevice *bus, uint chip_addr,
595 				uint chip_flags)
596 {
597 	struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
598 	struct iproc_i2c_regs *base = bus_prvdata->base;
599 	u32 regval;
600 
601 	debug("\n%s: Entering chip probe\n", __func__);
602 
603 	/* Init internal regs, disable intrs (and then clear intrs), set fifo
604 	 * thresholds, etc.
605 	 */
606 	if (!bus_prvdata->i2c_init_done)
607 		iproc_i2c_init(bus);
608 
609 	regval = (chip_addr << 1);
610 	iproc_i2c_reg_write(&base->mstr_datawr, regval);
611 	regval = ((SMBUS_PROT_QUICK_CMD << CCB_SMB_MSTRSMBUSPROTO_SHIFT) |
612 			(1 << CCB_SMB_MSTRSTARTBUSYCMD_SHIFT));
613 	iproc_i2c_reg_write(&base->mstr_cmd, regval);
614 
615 	do {
616 		udelay(100);
617 		regval = iproc_i2c_reg_read(&base->mstr_cmd);
618 		regval &= CCB_SMB_MSTRSTARTBUSYCMD_MASK;
619 	}  while (regval);
620 
621 	regval = iproc_i2c_reg_read(&base->mstr_cmd);
622 
623 	if ((regval & CCB_SMB_MSTRSTS_MASK) != 0)
624 		return -1;
625 
626 	iproc_dump_i2c_regs(bus_prvdata);
627 	debug("%s: chip probe successful\n", __func__);
628 
629 	return 0;
630 }
631 
iproc_i2c_set_bus_speed(struct udevice * bus,unsigned int speed)632 static int iproc_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
633 {
634 	struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
635 
636 	bus_prvdata->bus_speed = speed;
637 	return iproc_i2c_set_clk_freq(bus_prvdata);
638 }
639 
640 /**
641  * i2c_get_bus_speed - get i2c bus speed
642  *
643  * This function returns the speed of operation in Hz
644  */
iproc_i2c_get_bus_speed(struct udevice * bus)645 int iproc_i2c_get_bus_speed(struct udevice *bus)
646 {
647 	struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
648 	struct iproc_i2c_regs *base = bus_prvdata->base;
649 	unsigned int regval;
650 	int ret = 0;
651 
652 	regval = iproc_i2c_reg_read(&base->timg_cfg);
653 	regval = (regval & CCB_SMB_TIMGCFG_MODE400_MASK) >>
654 		  CCB_SMB_TIMGCFG_MODE400_SHIFT;
655 
656 	switch (regval) {
657 	case 0:
658 		ret = I2C_SPEED_STANDARD_RATE;
659 		break;
660 	case 1:
661 		ret = I2C_SPEED_FAST_RATE;
662 		break;
663 	default:
664 		ret = -EINVAL;
665 		break;
666 	}
667 
668 	return ret;
669 }
670 
iproc_i2c_probe(struct udevice * bus)671 static int iproc_i2c_probe(struct udevice *bus)
672 {
673 	return iproc_i2c_init(bus);
674 }
675 
iproc_i2c_of_to_plat(struct udevice * bus)676 static int iproc_i2c_of_to_plat(struct udevice *bus)
677 {
678 	struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
679 	int node = dev_of_offset(bus);
680 	const void *blob = gd->fdt_blob;
681 
682 	bus_prvdata->base = map_physmem(dev_read_addr(bus),
683 					sizeof(void *),
684 					MAP_NOCACHE);
685 
686 	bus_prvdata->bus_speed =
687 		fdtdec_get_int(blob, node, "bus-frequency",
688 			       I2C_SPEED_STANDARD_RATE);
689 
690 	return 0;
691 }
692 
693 static const struct dm_i2c_ops iproc_i2c_ops = {
694 	.xfer		= iproc_i2c_xfer,
695 	.probe_chip	= iproc_i2c_probe_chip,
696 	.set_bus_speed	= iproc_i2c_set_bus_speed,
697 	.get_bus_speed	= iproc_i2c_get_bus_speed,
698 };
699 
700 static const struct udevice_id iproc_i2c_ids[] = {
701 	{ .compatible = "brcm,iproc-i2c" },
702 	{ }
703 };
704 
705 U_BOOT_DRIVER(iproc_i2c) = {
706 	.name	= "iproc_i2c",
707 	.id	= UCLASS_I2C,
708 	.of_match = iproc_i2c_ids,
709 	.of_to_plat = iproc_i2c_of_to_plat,
710 	.probe	= iproc_i2c_probe,
711 	.priv_auto	= sizeof(struct iproc_i2c),
712 	.ops	= &iproc_i2c_ops,
713 	.flags  = DM_FLAG_PRE_RELOC,
714 };
715