1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2006,2009 Freescale Semiconductor, Inc.
4  *
5  * 2012, Heiko Schocher, DENX Software Engineering, hs@denx.de.
6  * Changes for multibus/multiadapter I2C support.
7  */
8 
9 #include <common.h>
10 #include <command.h>
11 #include <i2c.h>		/* Functional interface */
12 #include <log.h>
13 #include <time.h>
14 #include <asm/global_data.h>
15 #include <asm/io.h>
16 #include <asm/fsl_i2c.h>	/* HW definitions */
17 #include <clk.h>
18 #include <dm.h>
19 #include <mapmem.h>
20 #include <linux/delay.h>
21 
22 /* The maximum number of microseconds we will wait until another master has
23  * released the bus.  If not defined in the board header file, then use a
24  * generic value.
25  */
26 #ifndef CONFIG_I2C_MBB_TIMEOUT
27 #define CONFIG_I2C_MBB_TIMEOUT	100000
28 #endif
29 
30 /* The maximum number of microseconds we will wait for a read or write
31  * operation to complete.  If not defined in the board header file, then use a
32  * generic value.
33  */
34 #ifndef CONFIG_I2C_TIMEOUT
35 #define CONFIG_I2C_TIMEOUT	100000
36 #endif
37 
38 #define I2C_READ_BIT  1
39 #define I2C_WRITE_BIT 0
40 
41 DECLARE_GLOBAL_DATA_PTR;
42 
43 #if !CONFIG_IS_ENABLED(DM_I2C)
44 static const struct fsl_i2c_base *i2c_base[4] = {
45 	(struct fsl_i2c_base *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C_OFFSET),
46 #ifdef CONFIG_SYS_FSL_I2C2_OFFSET
47 	(struct fsl_i2c_base *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C2_OFFSET),
48 #endif
49 #ifdef CONFIG_SYS_FSL_I2C3_OFFSET
50 	(struct fsl_i2c_base *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C3_OFFSET),
51 #endif
52 #ifdef CONFIG_SYS_FSL_I2C4_OFFSET
53 	(struct fsl_i2c_base *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C4_OFFSET)
54 #endif
55 };
56 #endif
57 
58 /* I2C speed map for a DFSR value of 1 */
59 
60 #ifdef __M68K__
61 /*
62  * Map I2C frequency dividers to FDR and DFSR values
63  *
64  * This structure is used to define the elements of a table that maps I2C
65  * frequency divider (I2C clock rate divided by I2C bus speed) to a value to be
66  * programmed into the Frequency Divider Ratio (FDR) and Digital Filter
67  * Sampling Rate (DFSR) registers.
68  *
69  * The actual table should be defined in the board file, and it must be called
70  * fsl_i2c_speed_map[].
71  *
72  * The last entry of the table must have a value of {-1, X}, where X is same
73  * FDR/DFSR values as the second-to-last entry.  This guarantees that any
74  * search through the array will always find a match.
75  *
76  * The values of the divider must be in increasing numerical order, i.e.
77  * fsl_i2c_speed_map[x+1].divider > fsl_i2c_speed_map[x].divider.
78  *
79  * For this table, the values are based on a value of 1 for the DFSR
80  * register.  See the application note AN2919 "Determining the I2C Frequency
81  * Divider Ratio for SCL"
82  *
83  * ColdFire I2C frequency dividers for FDR values are different from
84  * PowerPC. The protocol to use the I2C module is still the same.
85  * A different table is defined and are based on MCF5xxx user manual.
86  *
87  */
88 static const struct {
89 	unsigned short divider;
90 	u8 fdr;
91 } fsl_i2c_speed_map[] = {
92 	{20, 32}, {22, 33}, {24, 34}, {26, 35},
93 	{28, 0}, {28, 36}, {30, 1}, {32, 37},
94 	{34, 2}, {36, 38}, {40, 3}, {40, 39},
95 	{44, 4}, {48, 5}, {48, 40}, {56, 6},
96 	{56, 41}, {64, 42}, {68, 7}, {72, 43},
97 	{80, 8}, {80, 44}, {88, 9}, {96, 41},
98 	{104, 10}, {112, 42}, {128, 11}, {128, 43},
99 	{144, 12}, {160, 13}, {160, 48}, {192, 14},
100 	{192, 49}, {224, 50}, {240, 15}, {256, 51},
101 	{288, 16}, {320, 17}, {320, 52}, {384, 18},
102 	{384, 53}, {448, 54}, {480, 19}, {512, 55},
103 	{576, 20}, {640, 21}, {640, 56}, {768, 22},
104 	{768, 57}, {960, 23}, {896, 58}, {1024, 59},
105 	{1152, 24}, {1280, 25}, {1280, 60}, {1536, 26},
106 	{1536, 61}, {1792, 62}, {1920, 27}, {2048, 63},
107 	{2304, 28}, {2560, 29}, {3072, 30}, {3840, 31},
108 	{-1, 31}
109 };
110 #endif
111 
112 /**
113  * Set the I2C bus speed for a given I2C device
114  *
115  * @param base: the I2C device registers
116  * @i2c_clk: I2C bus clock frequency
117  * @speed: the desired speed of the bus
118  *
119  * The I2C device must be stopped before calling this function.
120  *
121  * The return value is the actual bus speed that is set.
122  */
set_i2c_bus_speed(const struct fsl_i2c_base * base,uint i2c_clk,uint speed)123 static uint set_i2c_bus_speed(const struct fsl_i2c_base *base,
124 			      uint i2c_clk, uint speed)
125 {
126 	ushort divider = min(i2c_clk / speed, (uint)USHRT_MAX);
127 
128 	/*
129 	 * We want to choose an FDR/DFSR that generates an I2C bus speed that
130 	 * is equal to or lower than the requested speed.  That means that we
131 	 * want the first divider that is equal to or greater than the
132 	 * calculated divider.
133 	 */
134 #ifdef __PPC__
135 	u8 dfsr, fdr = 0x31; /* Default if no FDR found */
136 	/* a, b and dfsr matches identifiers A,B and C respectively in AN2919 */
137 	ushort a, b, ga, gb;
138 	ulong c_div, est_div;
139 
140 #ifdef CONFIG_FSL_I2C_CUSTOM_DFSR
141 	dfsr = CONFIG_FSL_I2C_CUSTOM_DFSR;
142 #else
143 	/* Condition 1: dfsr <= 50/T */
144 	dfsr = (5 * (i2c_clk / 1000)) / 100000;
145 #endif
146 #ifdef CONFIG_FSL_I2C_CUSTOM_FDR
147 	fdr = CONFIG_FSL_I2C_CUSTOM_FDR;
148 	speed = i2c_clk / divider; /* Fake something */
149 #else
150 	debug("Requested speed:%d, i2c_clk:%d\n", speed, i2c_clk);
151 	if (!dfsr)
152 		dfsr = 1;
153 
154 	est_div = ~0;
155 	for (ga = 0x4, a = 10; a <= 30; ga++, a += 2) {
156 		for (gb = 0; gb < 8; gb++) {
157 			b = 16 << gb;
158 			c_div = b * (a + ((3 * dfsr) / b) * 2);
159 			if (c_div > divider && c_div < est_div) {
160 				ushort bin_gb, bin_ga;
161 
162 				est_div = c_div;
163 				bin_gb = gb << 2;
164 				bin_ga = (ga & 0x3) | ((ga & 0x4) << 3);
165 				fdr = bin_gb | bin_ga;
166 				speed = i2c_clk / est_div;
167 
168 				debug("FDR: 0x%.2x, ", fdr);
169 				debug("div: %ld, ", est_div);
170 				debug("ga: 0x%x, gb: 0x%x, ", ga, gb);
171 				debug("a: %d, b: %d, speed: %d\n", a, b, speed);
172 
173 				/* Condition 2 not accounted for */
174 				debug("Tr <= %d ns\n",
175 				      (b - 3 * dfsr) * 1000000 /
176 				      (i2c_clk / 1000));
177 			}
178 		}
179 		if (a == 20)
180 			a += 2;
181 		if (a == 24)
182 			a += 4;
183 	}
184 	debug("divider: %d, est_div: %ld, DFSR: %d\n", divider, est_div, dfsr);
185 	debug("FDR: 0x%.2x, speed: %d\n", fdr, speed);
186 #endif
187 	writeb(dfsr, &base->dfsrr);	/* set default filter */
188 	writeb(fdr, &base->fdr);	/* set bus speed */
189 #else
190 	uint i;
191 
192 	for (i = 0; i < ARRAY_SIZE(fsl_i2c_speed_map); i++)
193 		if (fsl_i2c_speed_map[i].divider >= divider) {
194 			u8 fdr;
195 
196 			fdr = fsl_i2c_speed_map[i].fdr;
197 			speed = i2c_clk / fsl_i2c_speed_map[i].divider;
198 			writeb(fdr, &base->fdr);	/* set bus speed */
199 
200 			break;
201 		}
202 #endif
203 	return speed;
204 }
205 
206 #if !CONFIG_IS_ENABLED(DM_I2C)
get_i2c_clock(int bus)207 static uint get_i2c_clock(int bus)
208 {
209 	if (bus)
210 		return gd->arch.i2c2_clk;	/* I2C2 clock */
211 	else
212 		return gd->arch.i2c1_clk;	/* I2C1 clock */
213 }
214 #endif
215 
fsl_i2c_fixup(const struct fsl_i2c_base * base)216 static int fsl_i2c_fixup(const struct fsl_i2c_base *base)
217 {
218 	const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT);
219 	unsigned long long timeval = 0;
220 	int ret = -1;
221 	uint flags = 0;
222 
223 #ifdef CONFIG_SYS_FSL_ERRATUM_I2C_A004447
224 	uint svr = get_svr();
225 
226 	if ((SVR_SOC_VER(svr) == SVR_8548 && IS_SVR_REV(svr, 3, 1)) ||
227 	    (SVR_REV(svr) <= CONFIG_SYS_FSL_A004447_SVR_REV))
228 		flags = I2C_CR_BIT6;
229 #endif
230 
231 	writeb(I2C_CR_MEN | I2C_CR_MSTA, &base->cr);
232 
233 	timeval = get_ticks();
234 	while (!(readb(&base->sr) & I2C_SR_MBB)) {
235 		if ((get_ticks() - timeval) > timeout)
236 			goto err;
237 	}
238 
239 	if (readb(&base->sr) & I2C_SR_MAL) {
240 		/* SDA is stuck low */
241 		writeb(0, &base->cr);
242 		udelay(100);
243 		writeb(I2C_CR_MSTA | flags, &base->cr);
244 		writeb(I2C_CR_MEN | I2C_CR_MSTA | flags, &base->cr);
245 	}
246 
247 	readb(&base->dr);
248 
249 	timeval = get_ticks();
250 	while (!(readb(&base->sr) & I2C_SR_MIF)) {
251 		if ((get_ticks() - timeval) > timeout)
252 			goto err;
253 	}
254 	ret = 0;
255 
256 err:
257 	writeb(I2C_CR_MEN | flags, &base->cr);
258 	writeb(0, &base->sr);
259 	udelay(100);
260 
261 	return ret;
262 }
263 
__i2c_init(const struct fsl_i2c_base * base,int speed,int slaveadd,int i2c_clk,int busnum)264 static void __i2c_init(const struct fsl_i2c_base *base, int speed, int
265 		       slaveadd, int i2c_clk, int busnum)
266 {
267 	const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT);
268 	unsigned long long timeval;
269 
270 #ifdef CONFIG_SYS_I2C_INIT_BOARD
271 	/* Call board specific i2c bus reset routine before accessing the
272 	 * environment, which might be in a chip on that bus. For details
273 	 * about this problem see doc/I2C_Edge_Conditions.
274 	 */
275 	i2c_init_board();
276 #endif
277 	writeb(0, &base->cr);		/* stop I2C controller */
278 	udelay(5);			/* let it shutdown in peace */
279 	set_i2c_bus_speed(base, i2c_clk, speed);
280 	writeb(slaveadd << 1, &base->adr);/* write slave address */
281 	writeb(0x0, &base->sr);		/* clear status register */
282 	writeb(I2C_CR_MEN, &base->cr);	/* start I2C controller */
283 
284 	timeval = get_ticks();
285 	while (readb(&base->sr) & I2C_SR_MBB) {
286 		if ((get_ticks() - timeval) < timeout)
287 			continue;
288 
289 		if (fsl_i2c_fixup(base))
290 			debug("i2c_init: BUS#%d failed to init\n",
291 			      busnum);
292 
293 		break;
294 	}
295 }
296 
i2c_wait4bus(const struct fsl_i2c_base * base)297 static int i2c_wait4bus(const struct fsl_i2c_base *base)
298 {
299 	unsigned long long timeval = get_ticks();
300 	const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT);
301 
302 	while (readb(&base->sr) & I2C_SR_MBB) {
303 		if ((get_ticks() - timeval) > timeout)
304 			return -1;
305 	}
306 
307 	return 0;
308 }
309 
i2c_wait(const struct fsl_i2c_base * base,int write)310 static int i2c_wait(const struct fsl_i2c_base *base, int write)
311 {
312 	u32 csr;
313 	unsigned long long timeval = get_ticks();
314 	const unsigned long long timeout = usec2ticks(CONFIG_I2C_TIMEOUT);
315 
316 	do {
317 		csr = readb(&base->sr);
318 		if (!(csr & I2C_SR_MIF))
319 			continue;
320 		/* Read again to allow register to stabilise */
321 		csr = readb(&base->sr);
322 
323 		writeb(0x0, &base->sr);
324 
325 		if (csr & I2C_SR_MAL) {
326 			debug("%s: MAL\n", __func__);
327 			return -1;
328 		}
329 
330 		if (!(csr & I2C_SR_MCF))	{
331 			debug("%s: unfinished\n", __func__);
332 			return -1;
333 		}
334 
335 		if (write == I2C_WRITE_BIT && (csr & I2C_SR_RXAK)) {
336 			debug("%s: No RXACK\n", __func__);
337 			return -1;
338 		}
339 
340 		return 0;
341 	} while ((get_ticks() - timeval) < timeout);
342 
343 	debug("%s: timed out\n", __func__);
344 	return -1;
345 }
346 
i2c_write_addr(const struct fsl_i2c_base * base,u8 dev,u8 dir,int rsta)347 static int i2c_write_addr(const struct fsl_i2c_base *base, u8 dev,
348 			  u8 dir, int rsta)
349 {
350 	writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_MTX
351 	       | (rsta ? I2C_CR_RSTA : 0),
352 	       &base->cr);
353 
354 	writeb((dev << 1) | dir, &base->dr);
355 
356 	if (i2c_wait(base, I2C_WRITE_BIT) < 0)
357 		return 0;
358 
359 	return 1;
360 }
361 
__i2c_write_data(const struct fsl_i2c_base * base,u8 * data,int length)362 static int __i2c_write_data(const struct fsl_i2c_base *base, u8 *data,
363 			    int length)
364 {
365 	int i;
366 
367 	for (i = 0; i < length; i++) {
368 		writeb(data[i], &base->dr);
369 
370 		if (i2c_wait(base, I2C_WRITE_BIT) < 0)
371 			break;
372 	}
373 
374 	return i;
375 }
376 
__i2c_read_data(const struct fsl_i2c_base * base,u8 * data,int length)377 static int __i2c_read_data(const struct fsl_i2c_base *base, u8 *data,
378 			   int length)
379 {
380 	int i;
381 
382 	writeb(I2C_CR_MEN | I2C_CR_MSTA | ((length == 1) ? I2C_CR_TXAK : 0),
383 	       &base->cr);
384 
385 	/* dummy read */
386 	readb(&base->dr);
387 
388 	for (i = 0; i < length; i++) {
389 		if (i2c_wait(base, I2C_READ_BIT) < 0)
390 			break;
391 
392 		/* Generate ack on last next to last byte */
393 		if (i == length - 2)
394 			writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_TXAK,
395 			       &base->cr);
396 
397 		/* Do not generate stop on last byte */
398 		if (i == length - 1)
399 			writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_MTX,
400 			       &base->cr);
401 
402 		data[i] = readb(&base->dr);
403 	}
404 
405 	return i;
406 }
407 
__i2c_read(const struct fsl_i2c_base * base,u8 chip_addr,u8 * offset,int olen,u8 * data,int dlen)408 static int __i2c_read(const struct fsl_i2c_base *base, u8 chip_addr, u8 *offset,
409 		      int olen, u8 *data, int dlen)
410 {
411 	int ret = -1; /* signal error */
412 
413 	if (i2c_wait4bus(base) < 0)
414 		return -1;
415 
416 	/* Some drivers use offset lengths in excess of 4 bytes. These drivers
417 	 * adhere to the following convention:
418 	 * - the offset length is passed as negative (that is, the absolute
419 	 *   value of olen is the actual offset length)
420 	 * - the offset itself is passed in data, which is overwritten by the
421 	 *   subsequent read operation
422 	 */
423 	if (olen < 0) {
424 		if (i2c_write_addr(base, chip_addr, I2C_WRITE_BIT, 0) != 0)
425 			ret = __i2c_write_data(base, data, -olen);
426 
427 		if (ret != -olen)
428 			return -1;
429 
430 		if (dlen && i2c_write_addr(base, chip_addr,
431 					   I2C_READ_BIT, 1) != 0)
432 			ret = __i2c_read_data(base, data, dlen);
433 	} else {
434 		if ((!dlen || olen > 0) &&
435 		    i2c_write_addr(base, chip_addr, I2C_WRITE_BIT, 0) != 0  &&
436 		    __i2c_write_data(base, offset, olen) == olen)
437 			ret = 0; /* No error so far */
438 
439 		if (dlen && i2c_write_addr(base, chip_addr, I2C_READ_BIT,
440 					   olen ? 1 : 0) != 0)
441 			ret = __i2c_read_data(base, data, dlen);
442 	}
443 
444 	writeb(I2C_CR_MEN, &base->cr);
445 
446 	if (i2c_wait4bus(base)) /* Wait until STOP */
447 		debug("i2c_read: wait4bus timed out\n");
448 
449 	if (ret == dlen)
450 		return 0;
451 
452 	return -1;
453 }
454 
__i2c_write(const struct fsl_i2c_base * base,u8 chip_addr,u8 * offset,int olen,u8 * data,int dlen)455 static int __i2c_write(const struct fsl_i2c_base *base, u8 chip_addr,
456 		       u8 *offset, int olen, u8 *data, int dlen)
457 {
458 	int ret = -1; /* signal error */
459 
460 	if (i2c_wait4bus(base) < 0)
461 		return -1;
462 
463 	if (i2c_write_addr(base, chip_addr, I2C_WRITE_BIT, 0) != 0 &&
464 	    __i2c_write_data(base, offset, olen) == olen) {
465 		ret = __i2c_write_data(base, data, dlen);
466 	}
467 
468 	writeb(I2C_CR_MEN, &base->cr);
469 	if (i2c_wait4bus(base)) /* Wait until STOP */
470 		debug("i2c_write: wait4bus timed out\n");
471 
472 	if (ret == dlen)
473 		return 0;
474 
475 	return -1;
476 }
477 
__i2c_probe_chip(const struct fsl_i2c_base * base,uchar chip)478 static int __i2c_probe_chip(const struct fsl_i2c_base *base, uchar chip)
479 {
480 	/* For unknown reason the controller will ACK when
481 	 * probing for a slave with the same address, so skip
482 	 * it.
483 	 */
484 	if (chip == (readb(&base->adr) >> 1))
485 		return -1;
486 
487 	return __i2c_read(base, chip, 0, 0, NULL, 0);
488 }
489 
__i2c_set_bus_speed(const struct fsl_i2c_base * base,uint speed,int i2c_clk)490 static uint __i2c_set_bus_speed(const struct fsl_i2c_base *base,
491 				uint speed, int i2c_clk)
492 {
493 	writeb(0, &base->cr);		/* stop controller */
494 	set_i2c_bus_speed(base, i2c_clk, speed);
495 	writeb(I2C_CR_MEN, &base->cr);	/* start controller */
496 
497 	return 0;
498 }
499 
500 #if !CONFIG_IS_ENABLED(DM_I2C)
fsl_i2c_init(struct i2c_adapter * adap,int speed,int slaveadd)501 static void fsl_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
502 {
503 	__i2c_init(i2c_base[adap->hwadapnr], speed, slaveadd,
504 		   get_i2c_clock(adap->hwadapnr), adap->hwadapnr);
505 }
506 
fsl_i2c_probe_chip(struct i2c_adapter * adap,uchar chip)507 static int fsl_i2c_probe_chip(struct i2c_adapter *adap, uchar chip)
508 {
509 	return __i2c_probe_chip(i2c_base[adap->hwadapnr], chip);
510 }
511 
fsl_i2c_read(struct i2c_adapter * adap,u8 chip_addr,uint offset,int olen,u8 * data,int dlen)512 static int fsl_i2c_read(struct i2c_adapter *adap, u8 chip_addr, uint offset,
513 			int olen, u8 *data, int dlen)
514 {
515 	u8 *o = (u8 *)&offset;
516 
517 	return __i2c_read(i2c_base[adap->hwadapnr], chip_addr, &o[4 - olen],
518 			  olen, data, dlen);
519 }
520 
fsl_i2c_write(struct i2c_adapter * adap,u8 chip_addr,uint offset,int olen,u8 * data,int dlen)521 static int fsl_i2c_write(struct i2c_adapter *adap, u8 chip_addr, uint offset,
522 			 int olen, u8 *data, int dlen)
523 {
524 	u8 *o = (u8 *)&offset;
525 
526 	return __i2c_write(i2c_base[adap->hwadapnr], chip_addr, &o[4 - olen],
527 			   olen, data, dlen);
528 }
529 
fsl_i2c_set_bus_speed(struct i2c_adapter * adap,uint speed)530 static uint fsl_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
531 {
532 	return __i2c_set_bus_speed(i2c_base[adap->hwadapnr], speed,
533 				   get_i2c_clock(adap->hwadapnr));
534 }
535 
536 /*
537  * Register fsl i2c adapters
538  */
539 U_BOOT_I2C_ADAP_COMPLETE(fsl_0, fsl_i2c_init, fsl_i2c_probe_chip, fsl_i2c_read,
540 			 fsl_i2c_write, fsl_i2c_set_bus_speed,
541 			 CONFIG_SYS_FSL_I2C_SPEED, CONFIG_SYS_FSL_I2C_SLAVE,
542 			 0)
543 #ifdef CONFIG_SYS_FSL_I2C2_OFFSET
544 U_BOOT_I2C_ADAP_COMPLETE(fsl_1, fsl_i2c_init, fsl_i2c_probe_chip, fsl_i2c_read,
545 			 fsl_i2c_write, fsl_i2c_set_bus_speed,
546 			 CONFIG_SYS_FSL_I2C2_SPEED, CONFIG_SYS_FSL_I2C2_SLAVE,
547 			 1)
548 #endif
549 #ifdef CONFIG_SYS_FSL_I2C3_OFFSET
550 U_BOOT_I2C_ADAP_COMPLETE(fsl_2, fsl_i2c_init, fsl_i2c_probe_chip, fsl_i2c_read,
551 			 fsl_i2c_write, fsl_i2c_set_bus_speed,
552 			 CONFIG_SYS_FSL_I2C3_SPEED, CONFIG_SYS_FSL_I2C3_SLAVE,
553 			 2)
554 #endif
555 #ifdef CONFIG_SYS_FSL_I2C4_OFFSET
556 U_BOOT_I2C_ADAP_COMPLETE(fsl_3, fsl_i2c_init, fsl_i2c_probe_chip, fsl_i2c_read,
557 			 fsl_i2c_write, fsl_i2c_set_bus_speed,
558 			 CONFIG_SYS_FSL_I2C4_SPEED, CONFIG_SYS_FSL_I2C4_SLAVE,
559 			 3)
560 #endif
561 #else /* CONFIG_DM_I2C */
562 static int fsl_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
563 			      u32 chip_flags)
564 {
565 	struct fsl_i2c_dev *dev = dev_get_priv(bus);
566 
567 	return __i2c_probe_chip(dev->base, chip_addr);
568 }
569 
570 static int fsl_i2c_set_bus_speed(struct udevice *bus, uint speed)
571 {
572 	struct fsl_i2c_dev *dev = dev_get_priv(bus);
573 
574 	return __i2c_set_bus_speed(dev->base, speed, dev->i2c_clk);
575 }
576 
577 static int fsl_i2c_of_to_plat(struct udevice *bus)
578 {
579 	struct fsl_i2c_dev *dev = dev_get_priv(bus);
580 	struct clk clock;
581 
582 	dev->base = map_sysmem(dev_read_addr(bus), sizeof(struct fsl_i2c_base));
583 
584 	if (!dev->base)
585 		return -ENOMEM;
586 
587 	dev->index = dev_read_u32_default(bus, "cell-index", -1);
588 	dev->slaveadd = dev_read_u32_default(bus, "u-boot,i2c-slave-addr",
589 					     0x7f);
590 	dev->speed = dev_read_u32_default(bus, "clock-frequency",
591 					  I2C_SPEED_FAST_RATE);
592 
593 	if (!clk_get_by_index(bus, 0, &clock))
594 		dev->i2c_clk = clk_get_rate(&clock);
595 	else
596 		dev->i2c_clk = dev->index ? gd->arch.i2c2_clk :
597 					    gd->arch.i2c1_clk;
598 
599 	return 0;
600 }
601 
602 static int fsl_i2c_probe(struct udevice *bus)
603 {
604 	struct fsl_i2c_dev *dev = dev_get_priv(bus);
605 
606 	__i2c_init(dev->base, dev->speed, dev->slaveadd, dev->i2c_clk,
607 		   dev->index);
608 	return 0;
609 }
610 
611 static int fsl_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
612 {
613 	struct fsl_i2c_dev *dev = dev_get_priv(bus);
614 	struct i2c_msg *dmsg, *omsg, dummy;
615 
616 	memset(&dummy, 0, sizeof(struct i2c_msg));
617 
618 	/* We expect either two messages (one with an offset and one with the
619 	 * actual data) or one message (just data)
620 	 */
621 	if (nmsgs > 2 || nmsgs == 0) {
622 		debug("%s: Only one or two messages are supported.", __func__);
623 		return -1;
624 	}
625 
626 	omsg = nmsgs == 1 ? &dummy : msg;
627 	dmsg = nmsgs == 1 ? msg : msg + 1;
628 
629 	if (dmsg->flags & I2C_M_RD)
630 		return __i2c_read(dev->base, dmsg->addr, omsg->buf, omsg->len,
631 				  dmsg->buf, dmsg->len);
632 	else
633 		return __i2c_write(dev->base, dmsg->addr, omsg->buf, omsg->len,
634 				   dmsg->buf, dmsg->len);
635 }
636 
637 static const struct dm_i2c_ops fsl_i2c_ops = {
638 	.xfer           = fsl_i2c_xfer,
639 	.probe_chip     = fsl_i2c_probe_chip,
640 	.set_bus_speed  = fsl_i2c_set_bus_speed,
641 };
642 
643 static const struct udevice_id fsl_i2c_ids[] = {
644 	{ .compatible = "fsl-i2c", },
645 	{ /* sentinel */ }
646 };
647 
648 U_BOOT_DRIVER(i2c_fsl) = {
649 	.name = "i2c_fsl",
650 	.id = UCLASS_I2C,
651 	.of_match = fsl_i2c_ids,
652 	.probe = fsl_i2c_probe,
653 	.of_to_plat = fsl_i2c_of_to_plat,
654 	.priv_auto	= sizeof(struct fsl_i2c_dev),
655 	.ops = &fsl_i2c_ops,
656 };
657 
658 #endif /* CONFIG_DM_I2C */
659