xref: /openbmc/u-boot/drivers/i2c/mxc_i2c.c (revision 523849a0)
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 /* Register index */
36 #define IADR	0
37 #define IFDR	1
38 #define I2CR	2
39 #define I2SR	3
40 #define I2DR	4
41 
42 #define I2CR_IIEN	(1 << 6)
43 #define I2CR_MSTA	(1 << 5)
44 #define I2CR_MTX	(1 << 4)
45 #define I2CR_TX_NO_AK	(1 << 3)
46 #define I2CR_RSTA	(1 << 2)
47 
48 #define I2SR_ICF	(1 << 7)
49 #define I2SR_IBB	(1 << 5)
50 #define I2SR_IAL	(1 << 4)
51 #define I2SR_IIF	(1 << 1)
52 #define I2SR_RX_NO_AK	(1 << 0)
53 
54 #ifdef I2C_QUIRK_REG
55 #define I2CR_IEN	(0 << 7)
56 #define I2CR_IDIS	(1 << 7)
57 #define I2SR_IIF_CLEAR	(1 << 1)
58 #else
59 #define I2CR_IEN	(1 << 7)
60 #define I2CR_IDIS	(0 << 7)
61 #define I2SR_IIF_CLEAR	(0 << 1)
62 #endif
63 
64 #if defined(CONFIG_HARD_I2C) && !defined(CONFIG_SYS_I2C_BASE)
65 #error "define CONFIG_SYS_I2C_BASE to use the mxc_i2c driver"
66 #endif
67 
68 #ifdef I2C_QUIRK_REG
69 static u16 i2c_clk_div[60][2] = {
70 	{ 20,	0x00 }, { 22,	0x01 }, { 24,	0x02 }, { 26,	0x03 },
71 	{ 28,	0x04 },	{ 30,	0x05 },	{ 32,	0x09 }, { 34,	0x06 },
72 	{ 36,	0x0A }, { 40,	0x07 }, { 44,	0x0C }, { 48,	0x0D },
73 	{ 52,	0x43 },	{ 56,	0x0E }, { 60,	0x45 }, { 64,	0x12 },
74 	{ 68,	0x0F },	{ 72,	0x13 },	{ 80,	0x14 },	{ 88,	0x15 },
75 	{ 96,	0x19 },	{ 104,	0x16 },	{ 112,	0x1A },	{ 128,	0x17 },
76 	{ 136,	0x4F }, { 144,	0x1C },	{ 160,	0x1D }, { 176,	0x55 },
77 	{ 192,	0x1E }, { 208,	0x56 },	{ 224,	0x22 }, { 228,	0x24 },
78 	{ 240,	0x1F },	{ 256,	0x23 }, { 288,	0x5C },	{ 320,	0x25 },
79 	{ 384,	0x26 }, { 448,	0x2A },	{ 480,	0x27 }, { 512,	0x2B },
80 	{ 576,	0x2C },	{ 640,	0x2D },	{ 768,	0x31 }, { 896,	0x32 },
81 	{ 960,	0x2F },	{ 1024,	0x33 },	{ 1152,	0x34 }, { 1280,	0x35 },
82 	{ 1536,	0x36 }, { 1792,	0x3A },	{ 1920,	0x37 },	{ 2048,	0x3B },
83 	{ 2304,	0x3C },	{ 2560,	0x3D },	{ 3072,	0x3E }, { 3584,	0x7A },
84 	{ 3840,	0x3F }, { 4096,	0x7B }, { 5120,	0x7D },	{ 6144,	0x7E },
85 };
86 #else
87 static u16 i2c_clk_div[50][2] = {
88 	{ 22,	0x20 }, { 24,	0x21 }, { 26,	0x22 }, { 28,	0x23 },
89 	{ 30,	0x00 }, { 32,	0x24 }, { 36,	0x25 }, { 40,	0x26 },
90 	{ 42,	0x03 }, { 44,	0x27 }, { 48,	0x28 }, { 52,	0x05 },
91 	{ 56,	0x29 }, { 60,	0x06 }, { 64,	0x2A }, { 72,	0x2B },
92 	{ 80,	0x2C }, { 88,	0x09 }, { 96,	0x2D }, { 104,	0x0A },
93 	{ 112,	0x2E }, { 128,	0x2F }, { 144,	0x0C }, { 160,	0x30 },
94 	{ 192,	0x31 }, { 224,	0x32 }, { 240,	0x0F }, { 256,	0x33 },
95 	{ 288,	0x10 }, { 320,	0x34 }, { 384,	0x35 }, { 448,	0x36 },
96 	{ 480,	0x13 }, { 512,	0x37 }, { 576,	0x14 }, { 640,	0x38 },
97 	{ 768,	0x39 }, { 896,	0x3A }, { 960,	0x17 }, { 1024,	0x3B },
98 	{ 1152,	0x18 }, { 1280,	0x3C }, { 1536,	0x3D }, { 1792,	0x3E },
99 	{ 1920,	0x1B }, { 2048,	0x3F }, { 2304,	0x1C }, { 2560,	0x1D },
100 	{ 3072,	0x1E }, { 3840,	0x1F }
101 };
102 #endif
103 
104 #ifndef CONFIG_SYS_MXC_I2C1_SPEED
105 #define CONFIG_SYS_MXC_I2C1_SPEED 100000
106 #endif
107 #ifndef CONFIG_SYS_MXC_I2C2_SPEED
108 #define CONFIG_SYS_MXC_I2C2_SPEED 100000
109 #endif
110 #ifndef CONFIG_SYS_MXC_I2C3_SPEED
111 #define CONFIG_SYS_MXC_I2C3_SPEED 100000
112 #endif
113 #ifndef CONFIG_SYS_MXC_I2C4_SPEED
114 #define CONFIG_SYS_MXC_I2C4_SPEED 100000
115 #endif
116 
117 #ifndef CONFIG_SYS_MXC_I2C1_SLAVE
118 #define CONFIG_SYS_MXC_I2C1_SLAVE 0
119 #endif
120 #ifndef CONFIG_SYS_MXC_I2C2_SLAVE
121 #define CONFIG_SYS_MXC_I2C2_SLAVE 0
122 #endif
123 #ifndef CONFIG_SYS_MXC_I2C3_SLAVE
124 #define CONFIG_SYS_MXC_I2C3_SLAVE 0
125 #endif
126 #ifndef CONFIG_SYS_MXC_I2C4_SLAVE
127 #define CONFIG_SYS_MXC_I2C4_SLAVE 0
128 #endif
129 
130 /*
131  * Calculate and set proper clock divider
132  */
133 static uint8_t i2c_imx_get_clk(struct mxc_i2c_bus *i2c_bus, unsigned int rate)
134 {
135 	unsigned int i2c_clk_rate;
136 	unsigned int div;
137 	u8 clk_div;
138 
139 #if defined(CONFIG_MX31)
140 	struct clock_control_regs *sc_regs =
141 		(struct clock_control_regs *)CCM_BASE;
142 
143 	/* start the required I2C clock */
144 	writel(readl(&sc_regs->cgr0) | (3 << CONFIG_SYS_I2C_CLK_OFFSET),
145 		&sc_regs->cgr0);
146 #endif
147 
148 	/* Divider value calculation */
149 	i2c_clk_rate = mxc_get_clock(MXC_I2C_CLK);
150 	div = (i2c_clk_rate + rate - 1) / rate;
151 	if (div < i2c_clk_div[0][0])
152 		clk_div = 0;
153 	else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
154 		clk_div = ARRAY_SIZE(i2c_clk_div) - 1;
155 	else
156 		for (clk_div = 0; i2c_clk_div[clk_div][0] < div; clk_div++)
157 			;
158 
159 	/* Store divider value */
160 	return clk_div;
161 }
162 
163 /*
164  * Set I2C Bus speed
165  */
166 static int bus_i2c_set_bus_speed(struct mxc_i2c_bus *i2c_bus, int speed)
167 {
168 	ulong base = i2c_bus->base;
169 	bool quirk = i2c_bus->driver_data & I2C_QUIRK_FLAG ? true : false;
170 	u8 clk_idx = i2c_imx_get_clk(i2c_bus, speed);
171 	u8 idx = i2c_clk_div[clk_idx][1];
172 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
173 
174 	if (!base)
175 		return -ENODEV;
176 
177 	/* Store divider value */
178 	writeb(idx, base + (IFDR << reg_shift));
179 
180 	/* Reset module */
181 	writeb(I2CR_IDIS, base + (I2CR << reg_shift));
182 	writeb(0, base + (I2SR << reg_shift));
183 	return 0;
184 }
185 
186 #define ST_BUS_IDLE (0 | (I2SR_IBB << 8))
187 #define ST_BUS_BUSY (I2SR_IBB | (I2SR_IBB << 8))
188 #define ST_IIF (I2SR_IIF | (I2SR_IIF << 8))
189 
190 static int wait_for_sr_state(struct mxc_i2c_bus *i2c_bus, unsigned state)
191 {
192 	unsigned sr;
193 	ulong elapsed;
194 	bool quirk = i2c_bus->driver_data & I2C_QUIRK_FLAG ? true : false;
195 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
196 	ulong base = i2c_bus->base;
197 	ulong start_time = get_timer(0);
198 	for (;;) {
199 		sr = readb(base + (I2SR << reg_shift));
200 		if (sr & I2SR_IAL) {
201 			if (quirk)
202 				writeb(sr | I2SR_IAL, base +
203 				       (I2SR << reg_shift));
204 			else
205 				writeb(sr & ~I2SR_IAL, base +
206 				       (I2SR << reg_shift));
207 			printf("%s: Arbitration lost sr=%x cr=%x state=%x\n",
208 				__func__, sr, readb(base + (I2CR << reg_shift)),
209 				state);
210 			return -ERESTART;
211 		}
212 		if ((sr & (state >> 8)) == (unsigned char)state)
213 			return sr;
214 		WATCHDOG_RESET();
215 		elapsed = get_timer(start_time);
216 		if (elapsed > (CONFIG_SYS_HZ / 10))	/* .1 seconds */
217 			break;
218 	}
219 	printf("%s: failed sr=%x cr=%x state=%x\n", __func__,
220 	       sr, readb(base + (I2CR << reg_shift)), state);
221 	return -ETIMEDOUT;
222 }
223 
224 static int tx_byte(struct mxc_i2c_bus *i2c_bus, u8 byte)
225 {
226 	int ret;
227 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
228 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
229 	ulong base = i2c_bus->base;
230 
231 	writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
232 	writeb(byte, base + (I2DR << reg_shift));
233 
234 	ret = wait_for_sr_state(i2c_bus, ST_IIF);
235 	if (ret < 0)
236 		return ret;
237 	if (ret & I2SR_RX_NO_AK)
238 		return -ENODEV;
239 	return 0;
240 }
241 
242 /*
243  * Stub implementations for outer i2c slave operations.
244  */
245 void __i2c_force_reset_slave(void)
246 {
247 }
248 void i2c_force_reset_slave(void)
249 	__attribute__((weak, alias("__i2c_force_reset_slave")));
250 
251 /*
252  * Stop I2C transaction
253  */
254 static void i2c_imx_stop(struct mxc_i2c_bus *i2c_bus)
255 {
256 	int ret;
257 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
258 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
259 	ulong base = i2c_bus->base;
260 	unsigned int temp = readb(base + (I2CR << reg_shift));
261 
262 	temp &= ~(I2CR_MSTA | I2CR_MTX);
263 	writeb(temp, base + (I2CR << reg_shift));
264 	ret = wait_for_sr_state(i2c_bus, ST_BUS_IDLE);
265 	if (ret < 0)
266 		printf("%s:trigger stop failed\n", __func__);
267 }
268 
269 /*
270  * Send start signal, chip address and
271  * write register address
272  */
273 static int i2c_init_transfer_(struct mxc_i2c_bus *i2c_bus, u8 chip,
274 			      u32 addr, int alen)
275 {
276 	unsigned int temp;
277 	int ret;
278 	bool quirk = i2c_bus->driver_data & I2C_QUIRK_FLAG ? true : false;
279 	ulong base = i2c_bus->base;
280 	int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
281 
282 	/* Reset i2c slave */
283 	i2c_force_reset_slave();
284 
285 	/* Enable I2C controller */
286 	if (quirk)
287 		ret = readb(base + (I2CR << reg_shift)) & I2CR_IDIS;
288 	else
289 		ret = !(readb(base + (I2CR << reg_shift)) & I2CR_IEN);
290 
291 	if (ret) {
292 		writeb(I2CR_IEN, base + (I2CR << reg_shift));
293 		/* Wait for controller to be stable */
294 		udelay(50);
295 	}
296 
297 	if (readb(base + (IADR << reg_shift)) == (chip << 1))
298 		writeb((chip << 1) ^ 2, base + (IADR << reg_shift));
299 	writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
300 	ret = wait_for_sr_state(i2c_bus, ST_BUS_IDLE);
301 	if (ret < 0)
302 		return ret;
303 
304 	/* Start I2C transaction */
305 	temp = readb(base + (I2CR << reg_shift));
306 	temp |= I2CR_MSTA;
307 	writeb(temp, base + (I2CR << reg_shift));
308 
309 	ret = wait_for_sr_state(i2c_bus, ST_BUS_BUSY);
310 	if (ret < 0)
311 		return ret;
312 
313 	temp |= I2CR_MTX | I2CR_TX_NO_AK;
314 	writeb(temp, base + (I2CR << reg_shift));
315 
316 	/* write slave address */
317 	ret = tx_byte(i2c_bus, chip << 1);
318 	if (ret < 0)
319 		return ret;
320 
321 	while (alen--) {
322 		ret = tx_byte(i2c_bus, (addr >> (alen * 8)) & 0xff);
323 		if (ret < 0)
324 			return ret;
325 	}
326 	return 0;
327 }
328 
329 #ifndef CONFIG_DM_I2C
330 int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus)
331 {
332 	if (i2c_bus && i2c_bus->idle_bus_fn)
333 		return i2c_bus->idle_bus_fn(i2c_bus->idle_bus_data);
334 	return 0;
335 }
336 #else
337 /*
338  * See Linux Documentation/devicetree/bindings/i2c/i2c-imx.txt
339  * "
340  *  scl-gpios: specify the gpio related to SCL pin
341  *  sda-gpios: specify the gpio related to SDA pin
342  *  add pinctrl to configure i2c pins to gpio function for i2c
343  *  bus recovery, call it "gpio" state
344  * "
345  *
346  * The i2c_idle_bus is an implementation following Linux Kernel.
347  */
348 int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus)
349 {
350 	struct udevice *bus = i2c_bus->bus;
351 	struct gpio_desc *scl_gpio = &i2c_bus->scl_gpio;
352 	struct gpio_desc *sda_gpio = &i2c_bus->sda_gpio;
353 	int sda, scl;
354 	int i, ret = 0;
355 	ulong elapsed, start_time;
356 
357 	if (pinctrl_select_state(bus, "gpio")) {
358 		dev_dbg(bus, "Can not to switch to use gpio pinmux\n");
359 		/*
360 		 * GPIO pinctrl for i2c force idle is not a must,
361 		 * but it is strongly recommended to be used.
362 		 * Because it can help you to recover from bad
363 		 * i2c bus state. Do not return failure, because
364 		 * it is not a must.
365 		 */
366 		return 0;
367 	}
368 
369 	dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_IN);
370 	dm_gpio_set_dir_flags(sda_gpio, GPIOD_IS_IN);
371 	scl = dm_gpio_get_value(scl_gpio);
372 	sda = dm_gpio_get_value(sda_gpio);
373 
374 	if ((sda & scl) == 1)
375 		goto exit;		/* Bus is idle already */
376 
377 	/* Send high and low on the SCL line */
378 	for (i = 0; i < 9; i++) {
379 		dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_OUT);
380 		dm_gpio_set_value(scl_gpio, 0);
381 		udelay(50);
382 		dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_IN);
383 		udelay(50);
384 	}
385 	start_time = get_timer(0);
386 	for (;;) {
387 		dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_IN);
388 		dm_gpio_set_dir_flags(sda_gpio, GPIOD_IS_IN);
389 		scl = dm_gpio_get_value(scl_gpio);
390 		sda = dm_gpio_get_value(sda_gpio);
391 		if ((sda & scl) == 1)
392 			break;
393 		WATCHDOG_RESET();
394 		elapsed = get_timer(start_time);
395 		if (elapsed > (CONFIG_SYS_HZ / 5)) {	/* .2 seconds */
396 			ret = -EBUSY;
397 			printf("%s: failed to clear bus, sda=%d scl=%d\n", __func__, sda, scl);
398 			break;
399 		}
400 	}
401 
402 exit:
403 	pinctrl_select_state(bus, "default");
404 	return ret;
405 }
406 #endif
407 
408 static int i2c_init_transfer(struct mxc_i2c_bus *i2c_bus, u8 chip,
409 			     u32 addr, int alen)
410 {
411 	int retry;
412 	int ret;
413 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
414 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
415 
416 	if (!i2c_bus->base)
417 		return -ENODEV;
418 
419 	for (retry = 0; retry < 3; retry++) {
420 		ret = i2c_init_transfer_(i2c_bus, chip, addr, alen);
421 		if (ret >= 0)
422 			return 0;
423 		i2c_imx_stop(i2c_bus);
424 		if (ret == -ENODEV)
425 			return ret;
426 
427 		printf("%s: failed for chip 0x%x retry=%d\n", __func__, chip,
428 				retry);
429 		if (ret != -ERESTART)
430 			/* Disable controller */
431 			writeb(I2CR_IDIS, i2c_bus->base + (I2CR << reg_shift));
432 		udelay(100);
433 		if (i2c_idle_bus(i2c_bus) < 0)
434 			break;
435 	}
436 	printf("%s: give up i2c_regs=0x%lx\n", __func__, i2c_bus->base);
437 	return ret;
438 }
439 
440 
441 static int i2c_write_data(struct mxc_i2c_bus *i2c_bus, u8 chip, const u8 *buf,
442 			  int len)
443 {
444 	int i, ret = 0;
445 
446 	debug("i2c_write_data: chip=0x%x, len=0x%x\n", chip, len);
447 	debug("write_data: ");
448 	/* use rc for counter */
449 	for (i = 0; i < len; ++i)
450 		debug(" 0x%02x", buf[i]);
451 	debug("\n");
452 
453 	for (i = 0; i < len; i++) {
454 		ret = tx_byte(i2c_bus, buf[i]);
455 		if (ret < 0) {
456 			debug("i2c_write_data(): rc=%d\n", ret);
457 			break;
458 		}
459 	}
460 
461 	return ret;
462 }
463 
464 static int i2c_read_data(struct mxc_i2c_bus *i2c_bus, uchar chip, uchar *buf,
465 			 int len)
466 {
467 	int ret;
468 	unsigned int temp;
469 	int i;
470 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
471 			VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
472 	ulong base = i2c_bus->base;
473 
474 	debug("i2c_read_data: chip=0x%x, len=0x%x\n", chip, len);
475 
476 	/* setup bus to read data */
477 	temp = readb(base + (I2CR << reg_shift));
478 	temp &= ~(I2CR_MTX | I2CR_TX_NO_AK);
479 	if (len == 1)
480 		temp |= I2CR_TX_NO_AK;
481 	writeb(temp, base + (I2CR << reg_shift));
482 	writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
483 	/* dummy read to clear ICF */
484 	readb(base + (I2DR << reg_shift));
485 
486 	/* read data */
487 	for (i = 0; i < len; i++) {
488 		ret = wait_for_sr_state(i2c_bus, ST_IIF);
489 		if (ret < 0) {
490 			debug("i2c_read_data(): ret=%d\n", ret);
491 			i2c_imx_stop(i2c_bus);
492 			return ret;
493 		}
494 
495 		/*
496 		 * It must generate STOP before read I2DR to prevent
497 		 * controller from generating another clock cycle
498 		 */
499 		if (i == (len - 1)) {
500 			i2c_imx_stop(i2c_bus);
501 		} else if (i == (len - 2)) {
502 			temp = readb(base + (I2CR << reg_shift));
503 			temp |= I2CR_TX_NO_AK;
504 			writeb(temp, base + (I2CR << reg_shift));
505 		}
506 		writeb(I2SR_IIF_CLEAR, base + (I2SR << reg_shift));
507 		buf[i] = readb(base + (I2DR << reg_shift));
508 	}
509 
510 	/* reuse ret for counter*/
511 	for (ret = 0; ret < len; ++ret)
512 		debug(" 0x%02x", buf[ret]);
513 	debug("\n");
514 
515 	i2c_imx_stop(i2c_bus);
516 	return 0;
517 }
518 
519 #ifndef CONFIG_DM_I2C
520 /*
521  * Read data from I2C device
522  */
523 static int bus_i2c_read(struct mxc_i2c_bus *i2c_bus, u8 chip, u32 addr,
524 			int alen, u8 *buf, int len)
525 {
526 	int ret = 0;
527 	u32 temp;
528 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
529 		VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
530 	ulong base = i2c_bus->base;
531 
532 	ret = i2c_init_transfer(i2c_bus, chip, addr, alen);
533 	if (ret < 0)
534 		return ret;
535 
536 	temp = readb(base + (I2CR << reg_shift));
537 	temp |= I2CR_RSTA;
538 	writeb(temp, base + (I2CR << reg_shift));
539 
540 	ret = tx_byte(i2c_bus, (chip << 1) | 1);
541 	if (ret < 0) {
542 		i2c_imx_stop(i2c_bus);
543 		return ret;
544 	}
545 
546 	ret = i2c_read_data(i2c_bus, chip, buf, len);
547 
548 	i2c_imx_stop(i2c_bus);
549 	return ret;
550 }
551 
552 /*
553  * Write data to I2C device
554  */
555 static int bus_i2c_write(struct mxc_i2c_bus *i2c_bus, u8 chip, u32 addr,
556 			 int alen, const u8 *buf, int len)
557 {
558 	int ret = 0;
559 
560 	ret = i2c_init_transfer(i2c_bus, chip, addr, alen);
561 	if (ret < 0)
562 		return ret;
563 
564 	ret = i2c_write_data(i2c_bus, chip, buf, len);
565 
566 	i2c_imx_stop(i2c_bus);
567 
568 	return ret;
569 }
570 
571 #if !defined(I2C2_BASE_ADDR)
572 #define I2C2_BASE_ADDR	0
573 #endif
574 
575 #if !defined(I2C3_BASE_ADDR)
576 #define I2C3_BASE_ADDR	0
577 #endif
578 
579 #if !defined(I2C4_BASE_ADDR)
580 #define I2C4_BASE_ADDR	0
581 #endif
582 
583 static struct mxc_i2c_bus mxc_i2c_buses[] = {
584 #if defined(CONFIG_LS102XA) || defined(CONFIG_VF610) || \
585 	defined(CONFIG_FSL_LAYERSCAPE)
586 	{ 0, I2C1_BASE_ADDR, I2C_QUIRK_FLAG },
587 	{ 1, I2C2_BASE_ADDR, I2C_QUIRK_FLAG },
588 	{ 2, I2C3_BASE_ADDR, I2C_QUIRK_FLAG },
589 	{ 3, I2C4_BASE_ADDR, I2C_QUIRK_FLAG },
590 #else
591 	{ 0, I2C1_BASE_ADDR, 0 },
592 	{ 1, I2C2_BASE_ADDR, 0 },
593 	{ 2, I2C3_BASE_ADDR, 0 },
594 	{ 3, I2C4_BASE_ADDR, 0 },
595 #endif
596 };
597 
598 struct mxc_i2c_bus *i2c_get_base(struct i2c_adapter *adap)
599 {
600 	return &mxc_i2c_buses[adap->hwadapnr];
601 }
602 
603 static int mxc_i2c_read(struct i2c_adapter *adap, uint8_t chip,
604 				uint addr, int alen, uint8_t *buffer,
605 				int len)
606 {
607 	return bus_i2c_read(i2c_get_base(adap), chip, addr, alen, buffer, len);
608 }
609 
610 static int mxc_i2c_write(struct i2c_adapter *adap, uint8_t chip,
611 				uint addr, int alen, uint8_t *buffer,
612 				int len)
613 {
614 	return bus_i2c_write(i2c_get_base(adap), chip, addr, alen, buffer, len);
615 }
616 
617 /*
618  * Test if a chip at a given address responds (probe the chip)
619  */
620 static int mxc_i2c_probe(struct i2c_adapter *adap, uint8_t chip)
621 {
622 	return bus_i2c_write(i2c_get_base(adap), chip, 0, 0, NULL, 0);
623 }
624 
625 int __enable_i2c_clk(unsigned char enable, unsigned i2c_num)
626 {
627 	return 1;
628 }
629 int enable_i2c_clk(unsigned char enable, unsigned i2c_num)
630 	__attribute__((weak, alias("__enable_i2c_clk")));
631 
632 void bus_i2c_init(int index, int speed, int unused,
633 		  int (*idle_bus_fn)(void *p), void *idle_bus_data)
634 {
635 	int ret;
636 
637 	if (index >= ARRAY_SIZE(mxc_i2c_buses)) {
638 		debug("Error i2c index\n");
639 		return;
640 	}
641 
642 	/*
643 	 * Warning: Be careful to allow the assignment to a static
644 	 * variable here. This function could be called while U-Boot is
645 	 * still running in flash memory. So such assignment is equal
646 	 * to write data to flash without erasing.
647 	 */
648 	if (idle_bus_fn)
649 		mxc_i2c_buses[index].idle_bus_fn = idle_bus_fn;
650 	if (idle_bus_data)
651 		mxc_i2c_buses[index].idle_bus_data = idle_bus_data;
652 
653 	ret = enable_i2c_clk(1, index);
654 	if (ret < 0) {
655 		debug("I2C-%d clk fail to enable.\n", index);
656 		return;
657 	}
658 
659 	bus_i2c_set_bus_speed(&mxc_i2c_buses[index], speed);
660 }
661 
662 /*
663  * Init I2C Bus
664  */
665 static void mxc_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
666 {
667 	bus_i2c_init(adap->hwadapnr, speed, slaveaddr, NULL, NULL);
668 }
669 
670 /*
671  * Set I2C Speed
672  */
673 static u32 mxc_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
674 {
675 	return bus_i2c_set_bus_speed(i2c_get_base(adap), speed);
676 }
677 
678 /*
679  * Register mxc i2c adapters
680  */
681 #ifdef CONFIG_SYS_I2C_MXC_I2C1
682 U_BOOT_I2C_ADAP_COMPLETE(mxc0, mxc_i2c_init, mxc_i2c_probe,
683 			 mxc_i2c_read, mxc_i2c_write,
684 			 mxc_i2c_set_bus_speed,
685 			 CONFIG_SYS_MXC_I2C1_SPEED,
686 			 CONFIG_SYS_MXC_I2C1_SLAVE, 0)
687 #endif
688 
689 #ifdef CONFIG_SYS_I2C_MXC_I2C2
690 U_BOOT_I2C_ADAP_COMPLETE(mxc1, mxc_i2c_init, mxc_i2c_probe,
691 			 mxc_i2c_read, mxc_i2c_write,
692 			 mxc_i2c_set_bus_speed,
693 			 CONFIG_SYS_MXC_I2C2_SPEED,
694 			 CONFIG_SYS_MXC_I2C2_SLAVE, 1)
695 #endif
696 
697 #ifdef CONFIG_SYS_I2C_MXC_I2C3
698 U_BOOT_I2C_ADAP_COMPLETE(mxc2, mxc_i2c_init, mxc_i2c_probe,
699 			 mxc_i2c_read, mxc_i2c_write,
700 			 mxc_i2c_set_bus_speed,
701 			 CONFIG_SYS_MXC_I2C3_SPEED,
702 			 CONFIG_SYS_MXC_I2C3_SLAVE, 2)
703 #endif
704 
705 #ifdef CONFIG_SYS_I2C_MXC_I2C4
706 U_BOOT_I2C_ADAP_COMPLETE(mxc3, mxc_i2c_init, mxc_i2c_probe,
707 			 mxc_i2c_read, mxc_i2c_write,
708 			 mxc_i2c_set_bus_speed,
709 			 CONFIG_SYS_MXC_I2C4_SPEED,
710 			 CONFIG_SYS_MXC_I2C4_SLAVE, 3)
711 #endif
712 
713 #else
714 
715 static int mxc_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
716 {
717 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
718 
719 	return bus_i2c_set_bus_speed(i2c_bus, speed);
720 }
721 
722 static int mxc_i2c_probe(struct udevice *bus)
723 {
724 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
725 	const void *fdt = gd->fdt_blob;
726 	int node = bus->of_offset;
727 	fdt_addr_t addr;
728 	int ret, ret2;
729 
730 	i2c_bus->driver_data = dev_get_driver_data(bus);
731 
732 	addr = dev_get_addr(bus);
733 	if (addr == FDT_ADDR_T_NONE)
734 		return -ENODEV;
735 
736 	i2c_bus->base = addr;
737 	i2c_bus->index = bus->seq;
738 	i2c_bus->bus = bus;
739 
740 	/* Enable clk */
741 	ret = enable_i2c_clk(1, bus->seq);
742 	if (ret < 0)
743 		return ret;
744 
745 	/*
746 	 * See Documentation/devicetree/bindings/i2c/i2c-imx.txt
747 	 * Use gpio to force bus idle when necessary.
748 	 */
749 	ret = fdt_find_string(fdt, node, "pinctrl-names", "gpio");
750 	if (ret < 0) {
751 		dev_info(dev, "i2c bus %d at %lu, no gpio pinctrl state.\n", bus->seq, i2c_bus->base);
752 	} else {
753 		ret = gpio_request_by_name_nodev(fdt, node, "scl-gpios",
754 						 0, &i2c_bus->scl_gpio,
755 						 GPIOD_IS_OUT);
756 		ret2 = gpio_request_by_name_nodev(fdt, node, "sda-gpios",
757 						 0, &i2c_bus->sda_gpio,
758 						 GPIOD_IS_OUT);
759 		if (!dm_gpio_is_valid(&i2c_bus->sda_gpio) |
760 		    !dm_gpio_is_valid(&i2c_bus->scl_gpio) |
761 		    ret | ret2) {
762 			dev_err(dev, "i2c bus %d at %lu, fail to request scl/sda gpio\n", bus->seq, i2c_bus->base);
763 			return -ENODEV;
764 		}
765 	}
766 
767 	ret = i2c_idle_bus(i2c_bus);
768 	if (ret < 0) {
769 		/* Disable clk */
770 		enable_i2c_clk(0, bus->seq);
771 		return ret;
772 	}
773 
774 	/*
775 	 * Pinmux settings are in board file now, until pinmux is supported,
776 	 * we can set pinmux here in probe function.
777 	 */
778 
779 	debug("i2c : controller bus %d at %lu , speed %d: ",
780 	      bus->seq, i2c_bus->base,
781 	      i2c_bus->speed);
782 
783 	return 0;
784 }
785 
786 static int mxc_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
787 			      u32 chip_flags)
788 {
789 	int ret;
790 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
791 
792 	ret = i2c_init_transfer(i2c_bus, chip_addr, 0, 0);
793 	if (ret < 0) {
794 		debug("%s failed, ret = %d\n", __func__, ret);
795 		return ret;
796 	}
797 
798 	i2c_imx_stop(i2c_bus);
799 
800 	return 0;
801 }
802 
803 static int mxc_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
804 {
805 	struct mxc_i2c_bus *i2c_bus = dev_get_priv(bus);
806 	int ret = 0;
807 	ulong base = i2c_bus->base;
808 	int reg_shift = i2c_bus->driver_data & I2C_QUIRK_FLAG ?
809 		VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
810 
811 	/*
812 	 * Here the 3rd parameter addr and the 4th one alen are set to 0,
813 	 * because here we only want to send out chip address. The register
814 	 * address is wrapped in msg.
815 	 */
816 	ret = i2c_init_transfer(i2c_bus, msg->addr, 0, 0);
817 	if (ret < 0) {
818 		debug("i2c_init_transfer error: %d\n", ret);
819 		return ret;
820 	}
821 
822 	for (; nmsgs > 0; nmsgs--, msg++) {
823 		bool next_is_read = nmsgs > 1 && (msg[1].flags & I2C_M_RD);
824 		debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
825 		if (msg->flags & I2C_M_RD)
826 			ret = i2c_read_data(i2c_bus, msg->addr, msg->buf,
827 					    msg->len);
828 		else {
829 			ret = i2c_write_data(i2c_bus, msg->addr, msg->buf,
830 					     msg->len);
831 			if (ret)
832 				break;
833 			if (next_is_read) {
834 				/* Reuse ret */
835 				ret = readb(base + (I2CR << reg_shift));
836 				ret |= I2CR_RSTA;
837 				writeb(ret, base + (I2CR << reg_shift));
838 
839 				ret = tx_byte(i2c_bus, (msg->addr << 1) | 1);
840 				if (ret < 0) {
841 					i2c_imx_stop(i2c_bus);
842 					break;
843 				}
844 			}
845 		}
846 	}
847 
848 	if (ret)
849 		debug("i2c_write: error sending\n");
850 
851 	i2c_imx_stop(i2c_bus);
852 
853 	return ret;
854 }
855 
856 static const struct dm_i2c_ops mxc_i2c_ops = {
857 	.xfer		= mxc_i2c_xfer,
858 	.probe_chip	= mxc_i2c_probe_chip,
859 	.set_bus_speed	= mxc_i2c_set_bus_speed,
860 };
861 
862 static const struct udevice_id mxc_i2c_ids[] = {
863 	{ .compatible = "fsl,imx21-i2c", },
864 	{ .compatible = "fsl,vf610-i2c", .data = I2C_QUIRK_FLAG, },
865 	{}
866 };
867 
868 U_BOOT_DRIVER(i2c_mxc) = {
869 	.name = "i2c_mxc",
870 	.id = UCLASS_I2C,
871 	.of_match = mxc_i2c_ids,
872 	.probe = mxc_i2c_probe,
873 	.priv_auto_alloc_size = sizeof(struct mxc_i2c_bus),
874 	.ops = &mxc_i2c_ops,
875 };
876 #endif
877