xref: /openbmc/u-boot/drivers/i2c/mxc_i2c.c (revision 089df18b)
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 <linux/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 #ifdef I2C_QUIRK_REG
73 static u16 i2c_clk_div[60][2] = {
74 	{ 20,	0x00 }, { 22,	0x01 }, { 24,	0x02 }, { 26,	0x03 },
75 	{ 28,	0x04 },	{ 30,	0x05 },	{ 32,	0x09 }, { 34,	0x06 },
76 	{ 36,	0x0A }, { 40,	0x07 }, { 44,	0x0C }, { 48,	0x0D },
77 	{ 52,	0x43 },	{ 56,	0x0E }, { 60,	0x45 }, { 64,	0x12 },
78 	{ 68,	0x0F },	{ 72,	0x13 },	{ 80,	0x14 },	{ 88,	0x15 },
79 	{ 96,	0x19 },	{ 104,	0x16 },	{ 112,	0x1A },	{ 128,	0x17 },
80 	{ 136,	0x4F }, { 144,	0x1C },	{ 160,	0x1D }, { 176,	0x55 },
81 	{ 192,	0x1E }, { 208,	0x56 },	{ 224,	0x22 }, { 228,	0x24 },
82 	{ 240,	0x1F },	{ 256,	0x23 }, { 288,	0x5C },	{ 320,	0x25 },
83 	{ 384,	0x26 }, { 448,	0x2A },	{ 480,	0x27 }, { 512,	0x2B },
84 	{ 576,	0x2C },	{ 640,	0x2D },	{ 768,	0x31 }, { 896,	0x32 },
85 	{ 960,	0x2F },	{ 1024,	0x33 },	{ 1152,	0x34 }, { 1280,	0x35 },
86 	{ 1536,	0x36 }, { 1792,	0x3A },	{ 1920,	0x37 },	{ 2048,	0x3B },
87 	{ 2304,	0x3C },	{ 2560,	0x3D },	{ 3072,	0x3E }, { 3584,	0x7A },
88 	{ 3840,	0x3F }, { 4096,	0x7B }, { 5120,	0x7D },	{ 6144,	0x7E },
89 };
90 #else
91 static u16 i2c_clk_div[50][2] = {
92 	{ 22,	0x20 }, { 24,	0x21 }, { 26,	0x22 }, { 28,	0x23 },
93 	{ 30,	0x00 }, { 32,	0x24 }, { 36,	0x25 }, { 40,	0x26 },
94 	{ 42,	0x03 }, { 44,	0x27 }, { 48,	0x28 }, { 52,	0x05 },
95 	{ 56,	0x29 }, { 60,	0x06 }, { 64,	0x2A }, { 72,	0x2B },
96 	{ 80,	0x2C }, { 88,	0x09 }, { 96,	0x2D }, { 104,	0x0A },
97 	{ 112,	0x2E }, { 128,	0x2F }, { 144,	0x0C }, { 160,	0x30 },
98 	{ 192,	0x31 }, { 224,	0x32 }, { 240,	0x0F }, { 256,	0x33 },
99 	{ 288,	0x10 }, { 320,	0x34 }, { 384,	0x35 }, { 448,	0x36 },
100 	{ 480,	0x13 }, { 512,	0x37 }, { 576,	0x14 }, { 640,	0x38 },
101 	{ 768,	0x39 }, { 896,	0x3A }, { 960,	0x17 }, { 1024,	0x3B },
102 	{ 1152,	0x18 }, { 1280,	0x3C }, { 1536,	0x3D }, { 1792,	0x3E },
103 	{ 1920,	0x1B }, { 2048,	0x3F }, { 2304,	0x1C }, { 2560,	0x1D },
104 	{ 3072,	0x1E }, { 3840,	0x1F }
105 };
106 #endif
107 
108 #ifndef CONFIG_SYS_MXC_I2C1_SPEED
109 #define CONFIG_SYS_MXC_I2C1_SPEED 100000
110 #endif
111 #ifndef CONFIG_SYS_MXC_I2C2_SPEED
112 #define CONFIG_SYS_MXC_I2C2_SPEED 100000
113 #endif
114 #ifndef CONFIG_SYS_MXC_I2C3_SPEED
115 #define CONFIG_SYS_MXC_I2C3_SPEED 100000
116 #endif
117 #ifndef CONFIG_SYS_MXC_I2C4_SPEED
118 #define CONFIG_SYS_MXC_I2C4_SPEED 100000
119 #endif
120 
121 #ifndef CONFIG_SYS_MXC_I2C1_SLAVE
122 #define CONFIG_SYS_MXC_I2C1_SLAVE 0
123 #endif
124 #ifndef CONFIG_SYS_MXC_I2C2_SLAVE
125 #define CONFIG_SYS_MXC_I2C2_SLAVE 0
126 #endif
127 #ifndef CONFIG_SYS_MXC_I2C3_SLAVE
128 #define CONFIG_SYS_MXC_I2C3_SLAVE 0
129 #endif
130 #ifndef CONFIG_SYS_MXC_I2C4_SLAVE
131 #define CONFIG_SYS_MXC_I2C4_SLAVE 0
132 #endif
133 
134 /*
135  * Calculate and set proper clock divider
136  */
137 static uint8_t i2c_imx_get_clk(struct mxc_i2c_bus *i2c_bus, unsigned int rate)
138 {
139 	unsigned int i2c_clk_rate;
140 	unsigned int div;
141 	u8 clk_div;
142 
143 #if defined(CONFIG_MX31)
144 	struct clock_control_regs *sc_regs =
145 		(struct clock_control_regs *)CCM_BASE;
146 
147 	/* start the required I2C clock */
148 	writel(readl(&sc_regs->cgr0) | (3 << CONFIG_SYS_I2C_CLK_OFFSET),
149 		&sc_regs->cgr0);
150 #endif
151 
152 	/* Divider value calculation */
153 	i2c_clk_rate = mxc_get_clock(MXC_I2C_CLK);
154 	div = (i2c_clk_rate + rate - 1) / rate;
155 	if (div < i2c_clk_div[0][0])
156 		clk_div = 0;
157 	else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
158 		clk_div = ARRAY_SIZE(i2c_clk_div) - 1;
159 	else
160 		for (clk_div = 0; i2c_clk_div[clk_div][0] < div; clk_div++)
161 			;
162 
163 	/* Store divider value */
164 	return clk_div;
165 }
166 
167 /*
168  * Set I2C Bus speed
169  */
170 static int bus_i2c_set_bus_speed(struct mxc_i2c_bus *i2c_bus, int speed)
171 {
172 	ulong base = i2c_bus->base;
173 	bool quirk = i2c_bus->driver_data & I2C_QUIRK_FLAG ? true : false;
174 	u8 clk_idx = i2c_imx_get_clk(i2c_bus, speed);
175 	u8 idx = i2c_clk_div[clk_idx][1];
176 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
177 
178 	if (!base)
179 		return -ENODEV;
180 
181 	/* Store divider value */
182 	writeb(idx, base + (IFDR << reg_shift));
183 
184 	/* Reset module */
185 	writeb(I2CR_IDIS, base + (I2CR << reg_shift));
186 	writeb(0, base + (I2SR << reg_shift));
187 	return 0;
188 }
189 
190 #define ST_BUS_IDLE (0 | (I2SR_IBB << 8))
191 #define ST_BUS_BUSY (I2SR_IBB | (I2SR_IBB << 8))
192 #define ST_IIF (I2SR_IIF | (I2SR_IIF << 8))
193 
194 static int wait_for_sr_state(struct mxc_i2c_bus *i2c_bus, unsigned state)
195 {
196 	unsigned sr;
197 	ulong elapsed;
198 	bool quirk = i2c_bus->driver_data & I2C_QUIRK_FLAG ? true : false;
199 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
200 	ulong base = i2c_bus->base;
201 	ulong start_time = get_timer(0);
202 	for (;;) {
203 		sr = readb(base + (I2SR << reg_shift));
204 		if (sr & I2SR_IAL) {
205 			if (quirk)
206 				writeb(sr | I2SR_IAL, base +
207 				       (I2SR << reg_shift));
208 			else
209 				writeb(sr & ~I2SR_IAL, base +
210 				       (I2SR << reg_shift));
211 			printf("%s: Arbitration lost sr=%x cr=%x state=%x\n",
212 				__func__, sr, readb(base + (I2CR << reg_shift)),
213 				state);
214 			return -ERESTART;
215 		}
216 		if ((sr & (state >> 8)) == (unsigned char)state)
217 			return sr;
218 		WATCHDOG_RESET();
219 		elapsed = get_timer(start_time);
220 		if (elapsed > (CONFIG_SYS_HZ / 10))	/* .1 seconds */
221 			break;
222 	}
223 	printf("%s: failed sr=%x cr=%x state=%x\n", __func__,
224 	       sr, readb(base + (I2CR << reg_shift)), state);
225 	return -ETIMEDOUT;
226 }
227 
228 static int tx_byte(struct mxc_i2c_bus *i2c_bus, u8 byte)
229 {
230 	int ret;
231 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
232 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
233 	ulong base = i2c_bus->base;
234 
235 	writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
236 	writeb(byte, base + (I2DR << reg_shift));
237 
238 	ret = wait_for_sr_state(i2c_bus, ST_IIF);
239 	if (ret < 0)
240 		return ret;
241 	if (ret & I2SR_RX_NO_AK)
242 		return -ENODEV;
243 	return 0;
244 }
245 
246 /*
247  * Stub implementations for outer i2c slave operations.
248  */
249 void __i2c_force_reset_slave(void)
250 {
251 }
252 void i2c_force_reset_slave(void)
253 	__attribute__((weak, alias("__i2c_force_reset_slave")));
254 
255 /*
256  * Stop I2C transaction
257  */
258 static void i2c_imx_stop(struct mxc_i2c_bus *i2c_bus)
259 {
260 	int ret;
261 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
262 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
263 	ulong base = i2c_bus->base;
264 	unsigned int temp = readb(base + (I2CR << reg_shift));
265 
266 	temp &= ~(I2CR_MSTA | I2CR_MTX);
267 	writeb(temp, base + (I2CR << reg_shift));
268 	ret = wait_for_sr_state(i2c_bus, ST_BUS_IDLE);
269 	if (ret < 0)
270 		printf("%s:trigger stop failed\n", __func__);
271 }
272 
273 /*
274  * Send start signal, chip address and
275  * write register address
276  */
277 static int i2c_init_transfer_(struct mxc_i2c_bus *i2c_bus, u8 chip,
278 			      u32 addr, int alen)
279 {
280 	unsigned int temp;
281 	int ret;
282 	bool quirk = i2c_bus->driver_data & I2C_QUIRK_FLAG ? true : false;
283 	ulong base = i2c_bus->base;
284 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
285 
286 	/* Reset i2c slave */
287 	i2c_force_reset_slave();
288 
289 	/* Enable I2C controller */
290 	if (quirk)
291 		ret = readb(base + (I2CR << reg_shift)) & I2CR_IDIS;
292 	else
293 		ret = !(readb(base + (I2CR << reg_shift)) & I2CR_IEN);
294 
295 	if (ret) {
296 		writeb(I2CR_IEN, base + (I2CR << reg_shift));
297 		/* Wait for controller to be stable */
298 		udelay(50);
299 	}
300 
301 	if (readb(base + (IADR << reg_shift)) == (chip << 1))
302 		writeb((chip << 1) ^ 2, base + (IADR << reg_shift));
303 	writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
304 	ret = wait_for_sr_state(i2c_bus, ST_BUS_IDLE);
305 	if (ret < 0)
306 		return ret;
307 
308 	/* Start I2C transaction */
309 	temp = readb(base + (I2CR << reg_shift));
310 	temp |= I2CR_MSTA;
311 	writeb(temp, base + (I2CR << reg_shift));
312 
313 	ret = wait_for_sr_state(i2c_bus, ST_BUS_BUSY);
314 	if (ret < 0)
315 		return ret;
316 
317 	temp |= I2CR_MTX | I2CR_TX_NO_AK;
318 	writeb(temp, base + (I2CR << reg_shift));
319 
320 	/* write slave address */
321 	ret = tx_byte(i2c_bus, chip << 1);
322 	if (ret < 0)
323 		return ret;
324 
325 	while (alen--) {
326 		ret = tx_byte(i2c_bus, (addr >> (alen * 8)) & 0xff);
327 		if (ret < 0)
328 			return ret;
329 	}
330 	return 0;
331 }
332 
333 #ifndef CONFIG_DM_I2C
334 int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus)
335 {
336 	if (i2c_bus && i2c_bus->idle_bus_fn)
337 		return i2c_bus->idle_bus_fn(i2c_bus->idle_bus_data);
338 	return 0;
339 }
340 #else
341 /*
342  * See Linux Documentation/devicetree/bindings/i2c/i2c-imx.txt
343  * "
344  *  scl-gpios: specify the gpio related to SCL pin
345  *  sda-gpios: specify the gpio related to SDA pin
346  *  add pinctrl to configure i2c pins to gpio function for i2c
347  *  bus recovery, call it "gpio" state
348  * "
349  *
350  * The i2c_idle_bus is an implementation following Linux Kernel.
351  */
352 int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus)
353 {
354 	struct udevice *bus = i2c_bus->bus;
355 	struct gpio_desc *scl_gpio = &i2c_bus->scl_gpio;
356 	struct gpio_desc *sda_gpio = &i2c_bus->sda_gpio;
357 	int sda, scl;
358 	int i, ret = 0;
359 	ulong elapsed, start_time;
360 
361 	if (pinctrl_select_state(bus, "gpio")) {
362 		dev_dbg(bus, "Can not to switch to use gpio pinmux\n");
363 		/*
364 		 * GPIO pinctrl for i2c force idle is not a must,
365 		 * but it is strongly recommended to be used.
366 		 * Because it can help you to recover from bad
367 		 * i2c bus state. Do not return failure, because
368 		 * it is not a must.
369 		 */
370 		return 0;
371 	}
372 
373 	dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_IN);
374 	dm_gpio_set_dir_flags(sda_gpio, GPIOD_IS_IN);
375 	scl = dm_gpio_get_value(scl_gpio);
376 	sda = dm_gpio_get_value(sda_gpio);
377 
378 	if ((sda & scl) == 1)
379 		goto exit;		/* Bus is idle already */
380 
381 	/* Send high and low on the SCL line */
382 	for (i = 0; i < 9; i++) {
383 		dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_OUT);
384 		dm_gpio_set_value(scl_gpio, 0);
385 		udelay(50);
386 		dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_IN);
387 		udelay(50);
388 	}
389 	start_time = get_timer(0);
390 	for (;;) {
391 		dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_IN);
392 		dm_gpio_set_dir_flags(sda_gpio, GPIOD_IS_IN);
393 		scl = dm_gpio_get_value(scl_gpio);
394 		sda = dm_gpio_get_value(sda_gpio);
395 		if ((sda & scl) == 1)
396 			break;
397 		WATCHDOG_RESET();
398 		elapsed = get_timer(start_time);
399 		if (elapsed > (CONFIG_SYS_HZ / 5)) {	/* .2 seconds */
400 			ret = -EBUSY;
401 			printf("%s: failed to clear bus, sda=%d scl=%d\n", __func__, sda, scl);
402 			break;
403 		}
404 	}
405 
406 exit:
407 	pinctrl_select_state(bus, "default");
408 	return ret;
409 }
410 #endif
411 
412 static int i2c_init_transfer(struct mxc_i2c_bus *i2c_bus, u8 chip,
413 			     u32 addr, int alen)
414 {
415 	int retry;
416 	int ret;
417 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
418 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
419 
420 	if (!i2c_bus->base)
421 		return -ENODEV;
422 
423 	for (retry = 0; retry < 3; retry++) {
424 		ret = i2c_init_transfer_(i2c_bus, chip, addr, alen);
425 		if (ret >= 0)
426 			return 0;
427 		i2c_imx_stop(i2c_bus);
428 		if (ret == -ENODEV)
429 			return ret;
430 
431 		printf("%s: failed for chip 0x%x retry=%d\n", __func__, chip,
432 				retry);
433 		if (ret != -ERESTART)
434 			/* Disable controller */
435 			writeb(I2CR_IDIS, i2c_bus->base + (I2CR << reg_shift));
436 		udelay(100);
437 		if (i2c_idle_bus(i2c_bus) < 0)
438 			break;
439 	}
440 	printf("%s: give up i2c_regs=0x%lx\n", __func__, i2c_bus->base);
441 	return ret;
442 }
443 
444 
445 static int i2c_write_data(struct mxc_i2c_bus *i2c_bus, u8 chip, const u8 *buf,
446 			  int len)
447 {
448 	int i, ret = 0;
449 
450 	debug("i2c_write_data: chip=0x%x, len=0x%x\n", chip, len);
451 	debug("write_data: ");
452 	/* use rc for counter */
453 	for (i = 0; i < len; ++i)
454 		debug(" 0x%02x", buf[i]);
455 	debug("\n");
456 
457 	for (i = 0; i < len; i++) {
458 		ret = tx_byte(i2c_bus, buf[i]);
459 		if (ret < 0) {
460 			debug("i2c_write_data(): rc=%d\n", ret);
461 			break;
462 		}
463 	}
464 
465 	return ret;
466 }
467 
468 static int i2c_read_data(struct mxc_i2c_bus *i2c_bus, uchar chip, uchar *buf,
469 			 int len)
470 {
471 	int ret;
472 	unsigned int temp;
473 	int i;
474 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
475 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
476 	ulong base = i2c_bus->base;
477 
478 	debug("i2c_read_data: chip=0x%x, len=0x%x\n", chip, len);
479 
480 	/* setup bus to read data */
481 	temp = readb(base + (I2CR << reg_shift));
482 	temp &= ~(I2CR_MTX | I2CR_TX_NO_AK);
483 	if (len == 1)
484 		temp |= I2CR_TX_NO_AK;
485 	writeb(temp, base + (I2CR << reg_shift));
486 	writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
487 	/* dummy read to clear ICF */
488 	readb(base + (I2DR << reg_shift));
489 
490 	/* read data */
491 	for (i = 0; i < len; i++) {
492 		ret = wait_for_sr_state(i2c_bus, ST_IIF);
493 		if (ret < 0) {
494 			debug("i2c_read_data(): ret=%d\n", ret);
495 			i2c_imx_stop(i2c_bus);
496 			return ret;
497 		}
498 
499 		/*
500 		 * It must generate STOP before read I2DR to prevent
501 		 * controller from generating another clock cycle
502 		 */
503 		if (i == (len - 1)) {
504 			i2c_imx_stop(i2c_bus);
505 		} else if (i == (len - 2)) {
506 			temp = readb(base + (I2CR << reg_shift));
507 			temp |= I2CR_TX_NO_AK;
508 			writeb(temp, base + (I2CR << reg_shift));
509 		}
510 		writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
511 		buf[i] = readb(base + (I2DR << reg_shift));
512 	}
513 
514 	/* reuse ret for counter*/
515 	for (ret = 0; ret < len; ++ret)
516 		debug(" 0x%02x", buf[ret]);
517 	debug("\n");
518 
519 	i2c_imx_stop(i2c_bus);
520 	return 0;
521 }
522 
523 #ifndef CONFIG_DM_I2C
524 /*
525  * Read data from I2C device
526  */
527 static int bus_i2c_read(struct mxc_i2c_bus *i2c_bus, u8 chip, u32 addr,
528 			int alen, u8 *buf, int len)
529 {
530 	int ret = 0;
531 	u32 temp;
532 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
533 		VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
534 	ulong base = i2c_bus->base;
535 
536 	ret = i2c_init_transfer(i2c_bus, chip, addr, alen);
537 	if (ret < 0)
538 		return ret;
539 
540 	temp = readb(base + (I2CR << reg_shift));
541 	temp |= I2CR_RSTA;
542 	writeb(temp, base + (I2CR << reg_shift));
543 
544 	ret = tx_byte(i2c_bus, (chip << 1) | 1);
545 	if (ret < 0) {
546 		i2c_imx_stop(i2c_bus);
547 		return ret;
548 	}
549 
550 	ret = i2c_read_data(i2c_bus, chip, buf, len);
551 
552 	i2c_imx_stop(i2c_bus);
553 	return ret;
554 }
555 
556 /*
557  * Write data to I2C device
558  */
559 static int bus_i2c_write(struct mxc_i2c_bus *i2c_bus, u8 chip, u32 addr,
560 			 int alen, const u8 *buf, int len)
561 {
562 	int ret = 0;
563 
564 	ret = i2c_init_transfer(i2c_bus, chip, addr, alen);
565 	if (ret < 0)
566 		return ret;
567 
568 	ret = i2c_write_data(i2c_bus, chip, buf, len);
569 
570 	i2c_imx_stop(i2c_bus);
571 
572 	return ret;
573 }
574 
575 #if !defined(I2C2_BASE_ADDR)
576 #define I2C2_BASE_ADDR	0
577 #endif
578 
579 #if !defined(I2C3_BASE_ADDR)
580 #define I2C3_BASE_ADDR	0
581 #endif
582 
583 #if !defined(I2C4_BASE_ADDR)
584 #define I2C4_BASE_ADDR	0
585 #endif
586 
587 static struct mxc_i2c_bus mxc_i2c_buses[] = {
588 #if defined(CONFIG_ARCH_LS1021A) || defined(CONFIG_VF610) || \
589 	defined(CONFIG_FSL_LAYERSCAPE)
590 	{ 0, I2C1_BASE_ADDR, I2C_QUIRK_FLAG },
591 	{ 1, I2C2_BASE_ADDR, I2C_QUIRK_FLAG },
592 	{ 2, I2C3_BASE_ADDR, I2C_QUIRK_FLAG },
593 	{ 3, I2C4_BASE_ADDR, I2C_QUIRK_FLAG },
594 #else
595 	{ 0, I2C1_BASE_ADDR, 0 },
596 	{ 1, I2C2_BASE_ADDR, 0 },
597 	{ 2, I2C3_BASE_ADDR, 0 },
598 	{ 3, I2C4_BASE_ADDR, 0 },
599 #endif
600 };
601 
602 struct mxc_i2c_bus *i2c_get_base(struct i2c_adapter *adap)
603 {
604 	return &mxc_i2c_buses[adap->hwadapnr];
605 }
606 
607 static int mxc_i2c_read(struct i2c_adapter *adap, uint8_t chip,
608 				uint addr, int alen, uint8_t *buffer,
609 				int len)
610 {
611 	return bus_i2c_read(i2c_get_base(adap), chip, addr, alen, buffer, len);
612 }
613 
614 static int mxc_i2c_write(struct i2c_adapter *adap, uint8_t chip,
615 				uint addr, int alen, uint8_t *buffer,
616 				int len)
617 {
618 	return bus_i2c_write(i2c_get_base(adap), chip, addr, alen, buffer, len);
619 }
620 
621 /*
622  * Test if a chip at a given address responds (probe the chip)
623  */
624 static int mxc_i2c_probe(struct i2c_adapter *adap, uint8_t chip)
625 {
626 	return bus_i2c_write(i2c_get_base(adap), chip, 0, 0, NULL, 0);
627 }
628 
629 int __enable_i2c_clk(unsigned char enable, unsigned i2c_num)
630 {
631 	return 1;
632 }
633 int enable_i2c_clk(unsigned char enable, unsigned i2c_num)
634 	__attribute__((weak, alias("__enable_i2c_clk")));
635 
636 void bus_i2c_init(int index, int speed, int unused,
637 		  int (*idle_bus_fn)(void *p), void *idle_bus_data)
638 {
639 	int ret;
640 
641 	if (index >= ARRAY_SIZE(mxc_i2c_buses)) {
642 		debug("Error i2c index\n");
643 		return;
644 	}
645 
646 	/*
647 	 * Warning: Be careful to allow the assignment to a static
648 	 * variable here. This function could be called while U-Boot is
649 	 * still running in flash memory. So such assignment is equal
650 	 * to write data to flash without erasing.
651 	 */
652 	if (idle_bus_fn)
653 		mxc_i2c_buses[index].idle_bus_fn = idle_bus_fn;
654 	if (idle_bus_data)
655 		mxc_i2c_buses[index].idle_bus_data = idle_bus_data;
656 
657 	ret = enable_i2c_clk(1, index);
658 	if (ret < 0) {
659 		debug("I2C-%d clk fail to enable.\n", index);
660 		return;
661 	}
662 
663 	bus_i2c_set_bus_speed(&mxc_i2c_buses[index], speed);
664 }
665 
666 /*
667  * Early init I2C for prepare read the clk through I2C.
668  */
669 void i2c_early_init_f(void)
670 {
671 	ulong base = mxc_i2c_buses[I2C_EARLY_INIT_INDEX].base;
672 	bool quirk = mxc_i2c_buses[I2C_EARLY_INIT_INDEX].driver_data
673 					& I2C_QUIRK_FLAG ? true : false;
674 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
675 
676 	/* Set I2C divider value */
677 	writeb(I2C_IFDR_DIV_CONSERVATIVE, base + (IFDR << reg_shift));
678 	/* Reset module */
679 	writeb(I2CR_IDIS, base + (I2CR << reg_shift));
680 	writeb(0, base + (I2SR << reg_shift));
681 	/* Enable I2C */
682 	writeb(I2CR_IEN, base + (I2CR << reg_shift));
683 }
684 
685 /*
686  * Init I2C Bus
687  */
688 static void mxc_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
689 {
690 	bus_i2c_init(adap->hwadapnr, speed, slaveaddr, NULL, NULL);
691 }
692 
693 /*
694  * Set I2C Speed
695  */
696 static u32 mxc_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
697 {
698 	return bus_i2c_set_bus_speed(i2c_get_base(adap), speed);
699 }
700 
701 /*
702  * Register mxc i2c adapters
703  */
704 #ifdef CONFIG_SYS_I2C_MXC_I2C1
705 U_BOOT_I2C_ADAP_COMPLETE(mxc0, mxc_i2c_init, mxc_i2c_probe,
706 			 mxc_i2c_read, mxc_i2c_write,
707 			 mxc_i2c_set_bus_speed,
708 			 CONFIG_SYS_MXC_I2C1_SPEED,
709 			 CONFIG_SYS_MXC_I2C1_SLAVE, 0)
710 #endif
711 
712 #ifdef CONFIG_SYS_I2C_MXC_I2C2
713 U_BOOT_I2C_ADAP_COMPLETE(mxc1, mxc_i2c_init, mxc_i2c_probe,
714 			 mxc_i2c_read, mxc_i2c_write,
715 			 mxc_i2c_set_bus_speed,
716 			 CONFIG_SYS_MXC_I2C2_SPEED,
717 			 CONFIG_SYS_MXC_I2C2_SLAVE, 1)
718 #endif
719 
720 #ifdef CONFIG_SYS_I2C_MXC_I2C3
721 U_BOOT_I2C_ADAP_COMPLETE(mxc2, mxc_i2c_init, mxc_i2c_probe,
722 			 mxc_i2c_read, mxc_i2c_write,
723 			 mxc_i2c_set_bus_speed,
724 			 CONFIG_SYS_MXC_I2C3_SPEED,
725 			 CONFIG_SYS_MXC_I2C3_SLAVE, 2)
726 #endif
727 
728 #ifdef CONFIG_SYS_I2C_MXC_I2C4
729 U_BOOT_I2C_ADAP_COMPLETE(mxc3, mxc_i2c_init, mxc_i2c_probe,
730 			 mxc_i2c_read, mxc_i2c_write,
731 			 mxc_i2c_set_bus_speed,
732 			 CONFIG_SYS_MXC_I2C4_SPEED,
733 			 CONFIG_SYS_MXC_I2C4_SLAVE, 3)
734 #endif
735 
736 #else
737 
738 static int mxc_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
739 {
740 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
741 
742 	return bus_i2c_set_bus_speed(i2c_bus, speed);
743 }
744 
745 static int mxc_i2c_probe(struct udevice *bus)
746 {
747 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
748 	const void *fdt = gd->fdt_blob;
749 	int node = dev_of_offset(bus);
750 	fdt_addr_t addr;
751 	int ret, ret2;
752 
753 	i2c_bus->driver_data = dev_get_driver_data(bus);
754 
755 	addr = dev_get_addr(bus);
756 	if (addr == FDT_ADDR_T_NONE)
757 		return -ENODEV;
758 
759 	i2c_bus->base = addr;
760 	i2c_bus->index = bus->seq;
761 	i2c_bus->bus = bus;
762 
763 	/* Enable clk */
764 	ret = enable_i2c_clk(1, bus->seq);
765 	if (ret < 0)
766 		return ret;
767 
768 	/*
769 	 * See Documentation/devicetree/bindings/i2c/i2c-imx.txt
770 	 * Use gpio to force bus idle when necessary.
771 	 */
772 	ret = fdt_stringlist_search(fdt, node, "pinctrl-names", "gpio");
773 	if (ret < 0) {
774 		debug("i2c bus %d at 0x%2lx, no gpio pinctrl state.\n", bus->seq, i2c_bus->base);
775 	} else {
776 		ret = gpio_request_by_name_nodev(fdt, node, "scl-gpios",
777 						 0, &i2c_bus->scl_gpio,
778 						 GPIOD_IS_OUT);
779 		ret2 = gpio_request_by_name_nodev(fdt, node, "sda-gpios",
780 						 0, &i2c_bus->sda_gpio,
781 						 GPIOD_IS_OUT);
782 		if (!dm_gpio_is_valid(&i2c_bus->sda_gpio) |
783 		    !dm_gpio_is_valid(&i2c_bus->scl_gpio) |
784 		    ret | ret2) {
785 			dev_err(dev, "i2c bus %d at %lu, fail to request scl/sda gpio\n", bus->seq, i2c_bus->base);
786 			return -ENODEV;
787 		}
788 	}
789 
790 	ret = i2c_idle_bus(i2c_bus);
791 	if (ret < 0) {
792 		/* Disable clk */
793 		enable_i2c_clk(0, bus->seq);
794 		return ret;
795 	}
796 
797 	/*
798 	 * Pinmux settings are in board file now, until pinmux is supported,
799 	 * we can set pinmux here in probe function.
800 	 */
801 
802 	debug("i2c : controller bus %d at %lu , speed %d: ",
803 	      bus->seq, i2c_bus->base,
804 	      i2c_bus->speed);
805 
806 	return 0;
807 }
808 
809 static int mxc_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
810 			      u32 chip_flags)
811 {
812 	int ret;
813 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
814 
815 	ret = i2c_init_transfer(i2c_bus, chip_addr, 0, 0);
816 	if (ret < 0) {
817 		debug("%s failed, ret = %d\n", __func__, ret);
818 		return ret;
819 	}
820 
821 	i2c_imx_stop(i2c_bus);
822 
823 	return 0;
824 }
825 
826 static int mxc_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
827 {
828 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
829 	int ret = 0;
830 	ulong base = i2c_bus->base;
831 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
832 		VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
833 
834 	/*
835 	 * Here the 3rd parameter addr and the 4th one alen are set to 0,
836 	 * because here we only want to send out chip address. The register
837 	 * address is wrapped in msg.
838 	 */
839 	ret = i2c_init_transfer(i2c_bus, msg->addr, 0, 0);
840 	if (ret < 0) {
841 		debug("i2c_init_transfer error: %d\n", ret);
842 		return ret;
843 	}
844 
845 	for (; nmsgs > 0; nmsgs--, msg++) {
846 		bool next_is_read = nmsgs > 1 && (msg[1].flags & I2C_M_RD);
847 		debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
848 		if (msg->flags & I2C_M_RD)
849 			ret = i2c_read_data(i2c_bus, msg->addr, msg->buf,
850 					    msg->len);
851 		else {
852 			ret = i2c_write_data(i2c_bus, msg->addr, msg->buf,
853 					     msg->len);
854 			if (ret)
855 				break;
856 			if (next_is_read) {
857 				/* Reuse ret */
858 				ret = readb(base + (I2CR << reg_shift));
859 				ret |= I2CR_RSTA;
860 				writeb(ret, base + (I2CR << reg_shift));
861 
862 				ret = tx_byte(i2c_bus, (msg->addr << 1) | 1);
863 				if (ret < 0) {
864 					i2c_imx_stop(i2c_bus);
865 					break;
866 				}
867 			}
868 		}
869 	}
870 
871 	if (ret)
872 		debug("i2c_write: error sending\n");
873 
874 	i2c_imx_stop(i2c_bus);
875 
876 	return ret;
877 }
878 
879 static const struct dm_i2c_ops mxc_i2c_ops = {
880 	.xfer		= mxc_i2c_xfer,
881 	.probe_chip	= mxc_i2c_probe_chip,
882 	.set_bus_speed	= mxc_i2c_set_bus_speed,
883 };
884 
885 static const struct udevice_id mxc_i2c_ids[] = {
886 	{ .compatible = "fsl,imx21-i2c", },
887 	{ .compatible = "fsl,vf610-i2c", .data = I2C_QUIRK_FLAG, },
888 	{}
889 };
890 
891 U_BOOT_DRIVER(i2c_mxc) = {
892 	.name = "i2c_mxc",
893 	.id = UCLASS_I2C,
894 	.of_match = mxc_i2c_ids,
895 	.probe = mxc_i2c_probe,
896 	.priv_auto_alloc_size = sizeof(struct mxc_i2c_bus),
897 	.ops = &mxc_i2c_ops,
898 };
899 #endif
900