xref: /openbmc/u-boot/drivers/i2c/mxc_i2c.c (revision 215099a5)
1 /*
2  * i2c driver for Freescale i.MX series
3  *
4  * (c) 2007 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
5  * (c) 2011 Marek Vasut <marek.vasut@gmail.com>
6  *
7  * Based on i2c-imx.c from linux kernel:
8  *  Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de>
9  *  Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de>
10  *  Copyright (C) 2007 RightHand Technologies, Inc.
11  *  Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
12  *
13  *
14  * SPDX-License-Identifier:	GPL-2.0+
15  */
16 
17 #include <common.h>
18 #include <asm/arch/clock.h>
19 #include <asm/arch/imx-regs.h>
20 #include <asm/errno.h>
21 #include <asm/imx-common/mxc_i2c.h>
22 #include <asm/io.h>
23 #include <i2c.h>
24 #include <watchdog.h>
25 #include <dm.h>
26 #include <dm/pinctrl.h>
27 #include <fdtdec.h>
28 
29 DECLARE_GLOBAL_DATA_PTR;
30 
31 #define I2C_QUIRK_FLAG		(1 << 0)
32 
33 #define IMX_I2C_REGSHIFT	2
34 #define VF610_I2C_REGSHIFT	0
35 
36 #define I2C_EARLY_INIT_INDEX		0
37 #ifdef CONFIG_SYS_I2C_IFDR_DIV
38 #define I2C_IFDR_DIV_CONSERVATIVE	CONFIG_SYS_I2C_IFDR_DIV
39 #else
40 #define I2C_IFDR_DIV_CONSERVATIVE	0x7e
41 #endif
42 
43 /* Register index */
44 #define IADR	0
45 #define IFDR	1
46 #define I2CR	2
47 #define I2SR	3
48 #define I2DR	4
49 
50 #define I2CR_IIEN	(1 << 6)
51 #define I2CR_MSTA	(1 << 5)
52 #define I2CR_MTX	(1 << 4)
53 #define I2CR_TX_NO_AK	(1 << 3)
54 #define I2CR_RSTA	(1 << 2)
55 
56 #define I2SR_ICF	(1 << 7)
57 #define I2SR_IBB	(1 << 5)
58 #define I2SR_IAL	(1 << 4)
59 #define I2SR_IIF	(1 << 1)
60 #define I2SR_RX_NO_AK	(1 << 0)
61 
62 #ifdef I2C_QUIRK_REG
63 #define I2CR_IEN	(0 << 7)
64 #define I2CR_IDIS	(1 << 7)
65 #define I2SR_IIF_CLEAR	(1 << 1)
66 #else
67 #define I2CR_IEN	(1 << 7)
68 #define I2CR_IDIS	(0 << 7)
69 #define I2SR_IIF_CLEAR	(0 << 1)
70 #endif
71 
72 #if defined(CONFIG_HARD_I2C) && !defined(CONFIG_SYS_I2C_BASE)
73 #error "define CONFIG_SYS_I2C_BASE to use the mxc_i2c driver"
74 #endif
75 
76 #ifdef I2C_QUIRK_REG
77 static u16 i2c_clk_div[60][2] = {
78 	{ 20,	0x00 }, { 22,	0x01 }, { 24,	0x02 }, { 26,	0x03 },
79 	{ 28,	0x04 },	{ 30,	0x05 },	{ 32,	0x09 }, { 34,	0x06 },
80 	{ 36,	0x0A }, { 40,	0x07 }, { 44,	0x0C }, { 48,	0x0D },
81 	{ 52,	0x43 },	{ 56,	0x0E }, { 60,	0x45 }, { 64,	0x12 },
82 	{ 68,	0x0F },	{ 72,	0x13 },	{ 80,	0x14 },	{ 88,	0x15 },
83 	{ 96,	0x19 },	{ 104,	0x16 },	{ 112,	0x1A },	{ 128,	0x17 },
84 	{ 136,	0x4F }, { 144,	0x1C },	{ 160,	0x1D }, { 176,	0x55 },
85 	{ 192,	0x1E }, { 208,	0x56 },	{ 224,	0x22 }, { 228,	0x24 },
86 	{ 240,	0x1F },	{ 256,	0x23 }, { 288,	0x5C },	{ 320,	0x25 },
87 	{ 384,	0x26 }, { 448,	0x2A },	{ 480,	0x27 }, { 512,	0x2B },
88 	{ 576,	0x2C },	{ 640,	0x2D },	{ 768,	0x31 }, { 896,	0x32 },
89 	{ 960,	0x2F },	{ 1024,	0x33 },	{ 1152,	0x34 }, { 1280,	0x35 },
90 	{ 1536,	0x36 }, { 1792,	0x3A },	{ 1920,	0x37 },	{ 2048,	0x3B },
91 	{ 2304,	0x3C },	{ 2560,	0x3D },	{ 3072,	0x3E }, { 3584,	0x7A },
92 	{ 3840,	0x3F }, { 4096,	0x7B }, { 5120,	0x7D },	{ 6144,	0x7E },
93 };
94 #else
95 static u16 i2c_clk_div[50][2] = {
96 	{ 22,	0x20 }, { 24,	0x21 }, { 26,	0x22 }, { 28,	0x23 },
97 	{ 30,	0x00 }, { 32,	0x24 }, { 36,	0x25 }, { 40,	0x26 },
98 	{ 42,	0x03 }, { 44,	0x27 }, { 48,	0x28 }, { 52,	0x05 },
99 	{ 56,	0x29 }, { 60,	0x06 }, { 64,	0x2A }, { 72,	0x2B },
100 	{ 80,	0x2C }, { 88,	0x09 }, { 96,	0x2D }, { 104,	0x0A },
101 	{ 112,	0x2E }, { 128,	0x2F }, { 144,	0x0C }, { 160,	0x30 },
102 	{ 192,	0x31 }, { 224,	0x32 }, { 240,	0x0F }, { 256,	0x33 },
103 	{ 288,	0x10 }, { 320,	0x34 }, { 384,	0x35 }, { 448,	0x36 },
104 	{ 480,	0x13 }, { 512,	0x37 }, { 576,	0x14 }, { 640,	0x38 },
105 	{ 768,	0x39 }, { 896,	0x3A }, { 960,	0x17 }, { 1024,	0x3B },
106 	{ 1152,	0x18 }, { 1280,	0x3C }, { 1536,	0x3D }, { 1792,	0x3E },
107 	{ 1920,	0x1B }, { 2048,	0x3F }, { 2304,	0x1C }, { 2560,	0x1D },
108 	{ 3072,	0x1E }, { 3840,	0x1F }
109 };
110 #endif
111 
112 #ifndef CONFIG_SYS_MXC_I2C1_SPEED
113 #define CONFIG_SYS_MXC_I2C1_SPEED 100000
114 #endif
115 #ifndef CONFIG_SYS_MXC_I2C2_SPEED
116 #define CONFIG_SYS_MXC_I2C2_SPEED 100000
117 #endif
118 #ifndef CONFIG_SYS_MXC_I2C3_SPEED
119 #define CONFIG_SYS_MXC_I2C3_SPEED 100000
120 #endif
121 #ifndef CONFIG_SYS_MXC_I2C4_SPEED
122 #define CONFIG_SYS_MXC_I2C4_SPEED 100000
123 #endif
124 
125 #ifndef CONFIG_SYS_MXC_I2C1_SLAVE
126 #define CONFIG_SYS_MXC_I2C1_SLAVE 0
127 #endif
128 #ifndef CONFIG_SYS_MXC_I2C2_SLAVE
129 #define CONFIG_SYS_MXC_I2C2_SLAVE 0
130 #endif
131 #ifndef CONFIG_SYS_MXC_I2C3_SLAVE
132 #define CONFIG_SYS_MXC_I2C3_SLAVE 0
133 #endif
134 #ifndef CONFIG_SYS_MXC_I2C4_SLAVE
135 #define CONFIG_SYS_MXC_I2C4_SLAVE 0
136 #endif
137 
138 /*
139  * Calculate and set proper clock divider
140  */
141 static uint8_t i2c_imx_get_clk(struct mxc_i2c_bus *i2c_bus, unsigned int rate)
142 {
143 	unsigned int i2c_clk_rate;
144 	unsigned int div;
145 	u8 clk_div;
146 
147 #if defined(CONFIG_MX31)
148 	struct clock_control_regs *sc_regs =
149 		(struct clock_control_regs *)CCM_BASE;
150 
151 	/* start the required I2C clock */
152 	writel(readl(&sc_regs->cgr0) | (3 << CONFIG_SYS_I2C_CLK_OFFSET),
153 		&sc_regs->cgr0);
154 #endif
155 
156 	/* Divider value calculation */
157 	i2c_clk_rate = mxc_get_clock(MXC_I2C_CLK);
158 	div = (i2c_clk_rate + rate - 1) / rate;
159 	if (div < i2c_clk_div[0][0])
160 		clk_div = 0;
161 	else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
162 		clk_div = ARRAY_SIZE(i2c_clk_div) - 1;
163 	else
164 		for (clk_div = 0; i2c_clk_div[clk_div][0] < div; clk_div++)
165 			;
166 
167 	/* Store divider value */
168 	return clk_div;
169 }
170 
171 /*
172  * Set I2C Bus speed
173  */
174 static int bus_i2c_set_bus_speed(struct mxc_i2c_bus *i2c_bus, int speed)
175 {
176 	ulong base = i2c_bus->base;
177 	bool quirk = i2c_bus->driver_data & I2C_QUIRK_FLAG ? true : false;
178 	u8 clk_idx = i2c_imx_get_clk(i2c_bus, speed);
179 	u8 idx = i2c_clk_div[clk_idx][1];
180 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
181 
182 	if (!base)
183 		return -ENODEV;
184 
185 	/* Store divider value */
186 	writeb(idx, base + (IFDR << reg_shift));
187 
188 	/* Reset module */
189 	writeb(I2CR_IDIS, base + (I2CR << reg_shift));
190 	writeb(0, base + (I2SR << reg_shift));
191 	return 0;
192 }
193 
194 #define ST_BUS_IDLE (0 | (I2SR_IBB << 8))
195 #define ST_BUS_BUSY (I2SR_IBB | (I2SR_IBB << 8))
196 #define ST_IIF (I2SR_IIF | (I2SR_IIF << 8))
197 
198 static int wait_for_sr_state(struct mxc_i2c_bus *i2c_bus, unsigned state)
199 {
200 	unsigned sr;
201 	ulong elapsed;
202 	bool quirk = i2c_bus->driver_data & I2C_QUIRK_FLAG ? true : false;
203 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
204 	ulong base = i2c_bus->base;
205 	ulong start_time = get_timer(0);
206 	for (;;) {
207 		sr = readb(base + (I2SR << reg_shift));
208 		if (sr & I2SR_IAL) {
209 			if (quirk)
210 				writeb(sr | I2SR_IAL, base +
211 				       (I2SR << reg_shift));
212 			else
213 				writeb(sr & ~I2SR_IAL, base +
214 				       (I2SR << reg_shift));
215 			printf("%s: Arbitration lost sr=%x cr=%x state=%x\n",
216 				__func__, sr, readb(base + (I2CR << reg_shift)),
217 				state);
218 			return -ERESTART;
219 		}
220 		if ((sr & (state >> 8)) == (unsigned char)state)
221 			return sr;
222 		WATCHDOG_RESET();
223 		elapsed = get_timer(start_time);
224 		if (elapsed > (CONFIG_SYS_HZ / 10))	/* .1 seconds */
225 			break;
226 	}
227 	printf("%s: failed sr=%x cr=%x state=%x\n", __func__,
228 	       sr, readb(base + (I2CR << reg_shift)), state);
229 	return -ETIMEDOUT;
230 }
231 
232 static int tx_byte(struct mxc_i2c_bus *i2c_bus, u8 byte)
233 {
234 	int ret;
235 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
236 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
237 	ulong base = i2c_bus->base;
238 
239 	writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
240 	writeb(byte, base + (I2DR << reg_shift));
241 
242 	ret = wait_for_sr_state(i2c_bus, ST_IIF);
243 	if (ret < 0)
244 		return ret;
245 	if (ret & I2SR_RX_NO_AK)
246 		return -ENODEV;
247 	return 0;
248 }
249 
250 /*
251  * Stub implementations for outer i2c slave operations.
252  */
253 void __i2c_force_reset_slave(void)
254 {
255 }
256 void i2c_force_reset_slave(void)
257 	__attribute__((weak, alias("__i2c_force_reset_slave")));
258 
259 /*
260  * Stop I2C transaction
261  */
262 static void i2c_imx_stop(struct mxc_i2c_bus *i2c_bus)
263 {
264 	int ret;
265 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
266 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
267 	ulong base = i2c_bus->base;
268 	unsigned int temp = readb(base + (I2CR << reg_shift));
269 
270 	temp &= ~(I2CR_MSTA | I2CR_MTX);
271 	writeb(temp, base + (I2CR << reg_shift));
272 	ret = wait_for_sr_state(i2c_bus, ST_BUS_IDLE);
273 	if (ret < 0)
274 		printf("%s:trigger stop failed\n", __func__);
275 }
276 
277 /*
278  * Send start signal, chip address and
279  * write register address
280  */
281 static int i2c_init_transfer_(struct mxc_i2c_bus *i2c_bus, u8 chip,
282 			      u32 addr, int alen)
283 {
284 	unsigned int temp;
285 	int ret;
286 	bool quirk = i2c_bus->driver_data & I2C_QUIRK_FLAG ? true : false;
287 	ulong base = i2c_bus->base;
288 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
289 
290 	/* Reset i2c slave */
291 	i2c_force_reset_slave();
292 
293 	/* Enable I2C controller */
294 	if (quirk)
295 		ret = readb(base + (I2CR << reg_shift)) & I2CR_IDIS;
296 	else
297 		ret = !(readb(base + (I2CR << reg_shift)) & I2CR_IEN);
298 
299 	if (ret) {
300 		writeb(I2CR_IEN, base + (I2CR << reg_shift));
301 		/* Wait for controller to be stable */
302 		udelay(50);
303 	}
304 
305 	if (readb(base + (IADR << reg_shift)) == (chip << 1))
306 		writeb((chip << 1) ^ 2, base + (IADR << reg_shift));
307 	writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
308 	ret = wait_for_sr_state(i2c_bus, ST_BUS_IDLE);
309 	if (ret < 0)
310 		return ret;
311 
312 	/* Start I2C transaction */
313 	temp = readb(base + (I2CR << reg_shift));
314 	temp |= I2CR_MSTA;
315 	writeb(temp, base + (I2CR << reg_shift));
316 
317 	ret = wait_for_sr_state(i2c_bus, ST_BUS_BUSY);
318 	if (ret < 0)
319 		return ret;
320 
321 	temp |= I2CR_MTX | I2CR_TX_NO_AK;
322 	writeb(temp, base + (I2CR << reg_shift));
323 
324 	/* write slave address */
325 	ret = tx_byte(i2c_bus, chip << 1);
326 	if (ret < 0)
327 		return ret;
328 
329 	while (alen--) {
330 		ret = tx_byte(i2c_bus, (addr >> (alen * 8)) & 0xff);
331 		if (ret < 0)
332 			return ret;
333 	}
334 	return 0;
335 }
336 
337 #ifndef CONFIG_DM_I2C
338 int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus)
339 {
340 	if (i2c_bus && i2c_bus->idle_bus_fn)
341 		return i2c_bus->idle_bus_fn(i2c_bus->idle_bus_data);
342 	return 0;
343 }
344 #else
345 /*
346  * See Linux Documentation/devicetree/bindings/i2c/i2c-imx.txt
347  * "
348  *  scl-gpios: specify the gpio related to SCL pin
349  *  sda-gpios: specify the gpio related to SDA pin
350  *  add pinctrl to configure i2c pins to gpio function for i2c
351  *  bus recovery, call it "gpio" state
352  * "
353  *
354  * The i2c_idle_bus is an implementation following Linux Kernel.
355  */
356 int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus)
357 {
358 	struct udevice *bus = i2c_bus->bus;
359 	struct gpio_desc *scl_gpio = &i2c_bus->scl_gpio;
360 	struct gpio_desc *sda_gpio = &i2c_bus->sda_gpio;
361 	int sda, scl;
362 	int i, ret = 0;
363 	ulong elapsed, start_time;
364 
365 	if (pinctrl_select_state(bus, "gpio")) {
366 		dev_dbg(bus, "Can not to switch to use gpio pinmux\n");
367 		/*
368 		 * GPIO pinctrl for i2c force idle is not a must,
369 		 * but it is strongly recommended to be used.
370 		 * Because it can help you to recover from bad
371 		 * i2c bus state. Do not return failure, because
372 		 * it is not a must.
373 		 */
374 		return 0;
375 	}
376 
377 	dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_IN);
378 	dm_gpio_set_dir_flags(sda_gpio, GPIOD_IS_IN);
379 	scl = dm_gpio_get_value(scl_gpio);
380 	sda = dm_gpio_get_value(sda_gpio);
381 
382 	if ((sda & scl) == 1)
383 		goto exit;		/* Bus is idle already */
384 
385 	/* Send high and low on the SCL line */
386 	for (i = 0; i < 9; i++) {
387 		dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_OUT);
388 		dm_gpio_set_value(scl_gpio, 0);
389 		udelay(50);
390 		dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_IN);
391 		udelay(50);
392 	}
393 	start_time = get_timer(0);
394 	for (;;) {
395 		dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_IN);
396 		dm_gpio_set_dir_flags(sda_gpio, GPIOD_IS_IN);
397 		scl = dm_gpio_get_value(scl_gpio);
398 		sda = dm_gpio_get_value(sda_gpio);
399 		if ((sda & scl) == 1)
400 			break;
401 		WATCHDOG_RESET();
402 		elapsed = get_timer(start_time);
403 		if (elapsed > (CONFIG_SYS_HZ / 5)) {	/* .2 seconds */
404 			ret = -EBUSY;
405 			printf("%s: failed to clear bus, sda=%d scl=%d\n", __func__, sda, scl);
406 			break;
407 		}
408 	}
409 
410 exit:
411 	pinctrl_select_state(bus, "default");
412 	return ret;
413 }
414 #endif
415 
416 static int i2c_init_transfer(struct mxc_i2c_bus *i2c_bus, u8 chip,
417 			     u32 addr, int alen)
418 {
419 	int retry;
420 	int ret;
421 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
422 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
423 
424 	if (!i2c_bus->base)
425 		return -ENODEV;
426 
427 	for (retry = 0; retry < 3; retry++) {
428 		ret = i2c_init_transfer_(i2c_bus, chip, addr, alen);
429 		if (ret >= 0)
430 			return 0;
431 		i2c_imx_stop(i2c_bus);
432 		if (ret == -ENODEV)
433 			return ret;
434 
435 		printf("%s: failed for chip 0x%x retry=%d\n", __func__, chip,
436 				retry);
437 		if (ret != -ERESTART)
438 			/* Disable controller */
439 			writeb(I2CR_IDIS, i2c_bus->base + (I2CR << reg_shift));
440 		udelay(100);
441 		if (i2c_idle_bus(i2c_bus) < 0)
442 			break;
443 	}
444 	printf("%s: give up i2c_regs=0x%lx\n", __func__, i2c_bus->base);
445 	return ret;
446 }
447 
448 
449 static int i2c_write_data(struct mxc_i2c_bus *i2c_bus, u8 chip, const u8 *buf,
450 			  int len)
451 {
452 	int i, ret = 0;
453 
454 	debug("i2c_write_data: chip=0x%x, len=0x%x\n", chip, len);
455 	debug("write_data: ");
456 	/* use rc for counter */
457 	for (i = 0; i < len; ++i)
458 		debug(" 0x%02x", buf[i]);
459 	debug("\n");
460 
461 	for (i = 0; i < len; i++) {
462 		ret = tx_byte(i2c_bus, buf[i]);
463 		if (ret < 0) {
464 			debug("i2c_write_data(): rc=%d\n", ret);
465 			break;
466 		}
467 	}
468 
469 	return ret;
470 }
471 
472 static int i2c_read_data(struct mxc_i2c_bus *i2c_bus, uchar chip, uchar *buf,
473 			 int len)
474 {
475 	int ret;
476 	unsigned int temp;
477 	int i;
478 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
479 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
480 	ulong base = i2c_bus->base;
481 
482 	debug("i2c_read_data: chip=0x%x, len=0x%x\n", chip, len);
483 
484 	/* setup bus to read data */
485 	temp = readb(base + (I2CR << reg_shift));
486 	temp &= ~(I2CR_MTX | I2CR_TX_NO_AK);
487 	if (len == 1)
488 		temp |= I2CR_TX_NO_AK;
489 	writeb(temp, base + (I2CR << reg_shift));
490 	writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
491 	/* dummy read to clear ICF */
492 	readb(base + (I2DR << reg_shift));
493 
494 	/* read data */
495 	for (i = 0; i < len; i++) {
496 		ret = wait_for_sr_state(i2c_bus, ST_IIF);
497 		if (ret < 0) {
498 			debug("i2c_read_data(): ret=%d\n", ret);
499 			i2c_imx_stop(i2c_bus);
500 			return ret;
501 		}
502 
503 		/*
504 		 * It must generate STOP before read I2DR to prevent
505 		 * controller from generating another clock cycle
506 		 */
507 		if (i == (len - 1)) {
508 			i2c_imx_stop(i2c_bus);
509 		} else if (i == (len - 2)) {
510 			temp = readb(base + (I2CR << reg_shift));
511 			temp |= I2CR_TX_NO_AK;
512 			writeb(temp, base + (I2CR << reg_shift));
513 		}
514 		writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
515 		buf[i] = readb(base + (I2DR << reg_shift));
516 	}
517 
518 	/* reuse ret for counter*/
519 	for (ret = 0; ret < len; ++ret)
520 		debug(" 0x%02x", buf[ret]);
521 	debug("\n");
522 
523 	i2c_imx_stop(i2c_bus);
524 	return 0;
525 }
526 
527 #ifndef CONFIG_DM_I2C
528 /*
529  * Read data from I2C device
530  */
531 static int bus_i2c_read(struct mxc_i2c_bus *i2c_bus, u8 chip, u32 addr,
532 			int alen, u8 *buf, int len)
533 {
534 	int ret = 0;
535 	u32 temp;
536 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
537 		VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
538 	ulong base = i2c_bus->base;
539 
540 	ret = i2c_init_transfer(i2c_bus, chip, addr, alen);
541 	if (ret < 0)
542 		return ret;
543 
544 	temp = readb(base + (I2CR << reg_shift));
545 	temp |= I2CR_RSTA;
546 	writeb(temp, base + (I2CR << reg_shift));
547 
548 	ret = tx_byte(i2c_bus, (chip << 1) | 1);
549 	if (ret < 0) {
550 		i2c_imx_stop(i2c_bus);
551 		return ret;
552 	}
553 
554 	ret = i2c_read_data(i2c_bus, chip, buf, len);
555 
556 	i2c_imx_stop(i2c_bus);
557 	return ret;
558 }
559 
560 /*
561  * Write data to I2C device
562  */
563 static int bus_i2c_write(struct mxc_i2c_bus *i2c_bus, u8 chip, u32 addr,
564 			 int alen, const u8 *buf, int len)
565 {
566 	int ret = 0;
567 
568 	ret = i2c_init_transfer(i2c_bus, chip, addr, alen);
569 	if (ret < 0)
570 		return ret;
571 
572 	ret = i2c_write_data(i2c_bus, chip, buf, len);
573 
574 	i2c_imx_stop(i2c_bus);
575 
576 	return ret;
577 }
578 
579 #if !defined(I2C2_BASE_ADDR)
580 #define I2C2_BASE_ADDR	0
581 #endif
582 
583 #if !defined(I2C3_BASE_ADDR)
584 #define I2C3_BASE_ADDR	0
585 #endif
586 
587 #if !defined(I2C4_BASE_ADDR)
588 #define I2C4_BASE_ADDR	0
589 #endif
590 
591 static struct mxc_i2c_bus mxc_i2c_buses[] = {
592 #if defined(CONFIG_LS102XA) || defined(CONFIG_VF610) || \
593 	defined(CONFIG_FSL_LAYERSCAPE)
594 	{ 0, I2C1_BASE_ADDR, I2C_QUIRK_FLAG },
595 	{ 1, I2C2_BASE_ADDR, I2C_QUIRK_FLAG },
596 	{ 2, I2C3_BASE_ADDR, I2C_QUIRK_FLAG },
597 	{ 3, I2C4_BASE_ADDR, I2C_QUIRK_FLAG },
598 #else
599 	{ 0, I2C1_BASE_ADDR, 0 },
600 	{ 1, I2C2_BASE_ADDR, 0 },
601 	{ 2, I2C3_BASE_ADDR, 0 },
602 	{ 3, I2C4_BASE_ADDR, 0 },
603 #endif
604 };
605 
606 struct mxc_i2c_bus *i2c_get_base(struct i2c_adapter *adap)
607 {
608 	return &mxc_i2c_buses[adap->hwadapnr];
609 }
610 
611 static int mxc_i2c_read(struct i2c_adapter *adap, uint8_t chip,
612 				uint addr, int alen, uint8_t *buffer,
613 				int len)
614 {
615 	return bus_i2c_read(i2c_get_base(adap), chip, addr, alen, buffer, len);
616 }
617 
618 static int mxc_i2c_write(struct i2c_adapter *adap, uint8_t chip,
619 				uint addr, int alen, uint8_t *buffer,
620 				int len)
621 {
622 	return bus_i2c_write(i2c_get_base(adap), chip, addr, alen, buffer, len);
623 }
624 
625 /*
626  * Test if a chip at a given address responds (probe the chip)
627  */
628 static int mxc_i2c_probe(struct i2c_adapter *adap, uint8_t chip)
629 {
630 	return bus_i2c_write(i2c_get_base(adap), chip, 0, 0, NULL, 0);
631 }
632 
633 int __enable_i2c_clk(unsigned char enable, unsigned i2c_num)
634 {
635 	return 1;
636 }
637 int enable_i2c_clk(unsigned char enable, unsigned i2c_num)
638 	__attribute__((weak, alias("__enable_i2c_clk")));
639 
640 void bus_i2c_init(int index, int speed, int unused,
641 		  int (*idle_bus_fn)(void *p), void *idle_bus_data)
642 {
643 	int ret;
644 
645 	if (index >= ARRAY_SIZE(mxc_i2c_buses)) {
646 		debug("Error i2c index\n");
647 		return;
648 	}
649 
650 	/*
651 	 * Warning: Be careful to allow the assignment to a static
652 	 * variable here. This function could be called while U-Boot is
653 	 * still running in flash memory. So such assignment is equal
654 	 * to write data to flash without erasing.
655 	 */
656 	if (idle_bus_fn)
657 		mxc_i2c_buses[index].idle_bus_fn = idle_bus_fn;
658 	if (idle_bus_data)
659 		mxc_i2c_buses[index].idle_bus_data = idle_bus_data;
660 
661 	ret = enable_i2c_clk(1, index);
662 	if (ret < 0) {
663 		debug("I2C-%d clk fail to enable.\n", index);
664 		return;
665 	}
666 
667 	bus_i2c_set_bus_speed(&mxc_i2c_buses[index], speed);
668 }
669 
670 /*
671  * Early init I2C for prepare read the clk through I2C.
672  */
673 void i2c_early_init_f(void)
674 {
675 	ulong base = mxc_i2c_buses[I2C_EARLY_INIT_INDEX].base;
676 	bool quirk = mxc_i2c_buses[I2C_EARLY_INIT_INDEX].driver_data
677 					& I2C_QUIRK_FLAG ? true : false;
678 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
679 
680 	/* Set I2C divider value */
681 	writeb(I2C_IFDR_DIV_CONSERVATIVE, base + (IFDR << reg_shift));
682 	/* Reset module */
683 	writeb(I2CR_IDIS, base + (I2CR << reg_shift));
684 	writeb(0, base + (I2SR << reg_shift));
685 	/* Enable I2C */
686 	writeb(I2CR_IEN, base + (I2CR << reg_shift));
687 }
688 
689 /*
690  * Init I2C Bus
691  */
692 static void mxc_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
693 {
694 	bus_i2c_init(adap->hwadapnr, speed, slaveaddr, NULL, NULL);
695 }
696 
697 /*
698  * Set I2C Speed
699  */
700 static u32 mxc_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
701 {
702 	return bus_i2c_set_bus_speed(i2c_get_base(adap), speed);
703 }
704 
705 /*
706  * Register mxc i2c adapters
707  */
708 #ifdef CONFIG_SYS_I2C_MXC_I2C1
709 U_BOOT_I2C_ADAP_COMPLETE(mxc0, mxc_i2c_init, mxc_i2c_probe,
710 			 mxc_i2c_read, mxc_i2c_write,
711 			 mxc_i2c_set_bus_speed,
712 			 CONFIG_SYS_MXC_I2C1_SPEED,
713 			 CONFIG_SYS_MXC_I2C1_SLAVE, 0)
714 #endif
715 
716 #ifdef CONFIG_SYS_I2C_MXC_I2C2
717 U_BOOT_I2C_ADAP_COMPLETE(mxc1, mxc_i2c_init, mxc_i2c_probe,
718 			 mxc_i2c_read, mxc_i2c_write,
719 			 mxc_i2c_set_bus_speed,
720 			 CONFIG_SYS_MXC_I2C2_SPEED,
721 			 CONFIG_SYS_MXC_I2C2_SLAVE, 1)
722 #endif
723 
724 #ifdef CONFIG_SYS_I2C_MXC_I2C3
725 U_BOOT_I2C_ADAP_COMPLETE(mxc2, mxc_i2c_init, mxc_i2c_probe,
726 			 mxc_i2c_read, mxc_i2c_write,
727 			 mxc_i2c_set_bus_speed,
728 			 CONFIG_SYS_MXC_I2C3_SPEED,
729 			 CONFIG_SYS_MXC_I2C3_SLAVE, 2)
730 #endif
731 
732 #ifdef CONFIG_SYS_I2C_MXC_I2C4
733 U_BOOT_I2C_ADAP_COMPLETE(mxc3, mxc_i2c_init, mxc_i2c_probe,
734 			 mxc_i2c_read, mxc_i2c_write,
735 			 mxc_i2c_set_bus_speed,
736 			 CONFIG_SYS_MXC_I2C4_SPEED,
737 			 CONFIG_SYS_MXC_I2C4_SLAVE, 3)
738 #endif
739 
740 #else
741 
742 static int mxc_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
743 {
744 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
745 
746 	return bus_i2c_set_bus_speed(i2c_bus, speed);
747 }
748 
749 static int mxc_i2c_probe(struct udevice *bus)
750 {
751 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
752 	const void *fdt = gd->fdt_blob;
753 	int node = bus->of_offset;
754 	fdt_addr_t addr;
755 	int ret, ret2;
756 
757 	i2c_bus->driver_data = dev_get_driver_data(bus);
758 
759 	addr = dev_get_addr(bus);
760 	if (addr == FDT_ADDR_T_NONE)
761 		return -ENODEV;
762 
763 	i2c_bus->base = addr;
764 	i2c_bus->index = bus->seq;
765 	i2c_bus->bus = bus;
766 
767 	/* Enable clk */
768 	ret = enable_i2c_clk(1, bus->seq);
769 	if (ret < 0)
770 		return ret;
771 
772 	/*
773 	 * See Documentation/devicetree/bindings/i2c/i2c-imx.txt
774 	 * Use gpio to force bus idle when necessary.
775 	 */
776 	ret = fdt_find_string(fdt, node, "pinctrl-names", "gpio");
777 	if (ret < 0) {
778 		dev_info(dev, "i2c bus %d at %lu, no gpio pinctrl state.\n", bus->seq, i2c_bus->base);
779 	} else {
780 		ret = gpio_request_by_name_nodev(fdt, node, "scl-gpios",
781 						 0, &i2c_bus->scl_gpio,
782 						 GPIOD_IS_OUT);
783 		ret2 = gpio_request_by_name_nodev(fdt, node, "sda-gpios",
784 						 0, &i2c_bus->sda_gpio,
785 						 GPIOD_IS_OUT);
786 		if (!dm_gpio_is_valid(&i2c_bus->sda_gpio) |
787 		    !dm_gpio_is_valid(&i2c_bus->scl_gpio) |
788 		    ret | ret2) {
789 			dev_err(dev, "i2c bus %d at %lu, fail to request scl/sda gpio\n", bus->seq, i2c_bus->base);
790 			return -ENODEV;
791 		}
792 	}
793 
794 	ret = i2c_idle_bus(i2c_bus);
795 	if (ret < 0) {
796 		/* Disable clk */
797 		enable_i2c_clk(0, bus->seq);
798 		return ret;
799 	}
800 
801 	/*
802 	 * Pinmux settings are in board file now, until pinmux is supported,
803 	 * we can set pinmux here in probe function.
804 	 */
805 
806 	debug("i2c : controller bus %d at %lu , speed %d: ",
807 	      bus->seq, i2c_bus->base,
808 	      i2c_bus->speed);
809 
810 	return 0;
811 }
812 
813 static int mxc_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
814 			      u32 chip_flags)
815 {
816 	int ret;
817 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
818 
819 	ret = i2c_init_transfer(i2c_bus, chip_addr, 0, 0);
820 	if (ret < 0) {
821 		debug("%s failed, ret = %d\n", __func__, ret);
822 		return ret;
823 	}
824 
825 	i2c_imx_stop(i2c_bus);
826 
827 	return 0;
828 }
829 
830 static int mxc_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
831 {
832 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
833 	int ret = 0;
834 	ulong base = i2c_bus->base;
835 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
836 		VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
837 
838 	/*
839 	 * Here the 3rd parameter addr and the 4th one alen are set to 0,
840 	 * because here we only want to send out chip address. The register
841 	 * address is wrapped in msg.
842 	 */
843 	ret = i2c_init_transfer(i2c_bus, msg->addr, 0, 0);
844 	if (ret < 0) {
845 		debug("i2c_init_transfer error: %d\n", ret);
846 		return ret;
847 	}
848 
849 	for (; nmsgs > 0; nmsgs--, msg++) {
850 		bool next_is_read = nmsgs > 1 && (msg[1].flags & I2C_M_RD);
851 		debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
852 		if (msg->flags & I2C_M_RD)
853 			ret = i2c_read_data(i2c_bus, msg->addr, msg->buf,
854 					    msg->len);
855 		else {
856 			ret = i2c_write_data(i2c_bus, msg->addr, msg->buf,
857 					     msg->len);
858 			if (ret)
859 				break;
860 			if (next_is_read) {
861 				/* Reuse ret */
862 				ret = readb(base + (I2CR << reg_shift));
863 				ret |= I2CR_RSTA;
864 				writeb(ret, base + (I2CR << reg_shift));
865 
866 				ret = tx_byte(i2c_bus, (msg->addr << 1) | 1);
867 				if (ret < 0) {
868 					i2c_imx_stop(i2c_bus);
869 					break;
870 				}
871 			}
872 		}
873 	}
874 
875 	if (ret)
876 		debug("i2c_write: error sending\n");
877 
878 	i2c_imx_stop(i2c_bus);
879 
880 	return ret;
881 }
882 
883 static const struct dm_i2c_ops mxc_i2c_ops = {
884 	.xfer		= mxc_i2c_xfer,
885 	.probe_chip	= mxc_i2c_probe_chip,
886 	.set_bus_speed	= mxc_i2c_set_bus_speed,
887 };
888 
889 static const struct udevice_id mxc_i2c_ids[] = {
890 	{ .compatible = "fsl,imx21-i2c", },
891 	{ .compatible = "fsl,vf610-i2c", .data = I2C_QUIRK_FLAG, },
892 	{}
893 };
894 
895 U_BOOT_DRIVER(i2c_mxc) = {
896 	.name = "i2c_mxc",
897 	.id = UCLASS_I2C,
898 	.of_match = mxc_i2c_ids,
899 	.probe = mxc_i2c_probe,
900 	.priv_auto_alloc_size = sizeof(struct mxc_i2c_bus),
901 	.ops = &mxc_i2c_ops,
902 };
903 #endif
904