xref: /openbmc/linux/drivers/i2c/busses/i2c-qup.c (revision afb46f79)
1 /*
2  * Copyright (c) 2009-2013, The Linux Foundation. All rights reserved.
3  * Copyright (c) 2014, Sony Mobile Communications AB.
4  *
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 and
8  * only version 2 as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  */
16 
17 #include <linux/clk.h>
18 #include <linux/delay.h>
19 #include <linux/err.h>
20 #include <linux/i2c.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23 #include <linux/module.h>
24 #include <linux/of.h>
25 #include <linux/platform_device.h>
26 #include <linux/pm_runtime.h>
27 
28 /* QUP Registers */
29 #define QUP_CONFIG		0x000
30 #define QUP_STATE		0x004
31 #define QUP_IO_MODE		0x008
32 #define QUP_SW_RESET		0x00c
33 #define QUP_OPERATIONAL		0x018
34 #define QUP_ERROR_FLAGS		0x01c
35 #define QUP_ERROR_FLAGS_EN	0x020
36 #define QUP_HW_VERSION		0x030
37 #define QUP_MX_OUTPUT_CNT	0x100
38 #define QUP_OUT_FIFO_BASE	0x110
39 #define QUP_MX_WRITE_CNT	0x150
40 #define QUP_MX_INPUT_CNT	0x200
41 #define QUP_MX_READ_CNT		0x208
42 #define QUP_IN_FIFO_BASE	0x218
43 #define QUP_I2C_CLK_CTL		0x400
44 #define QUP_I2C_STATUS		0x404
45 
46 /* QUP States and reset values */
47 #define QUP_RESET_STATE		0
48 #define QUP_RUN_STATE		1
49 #define QUP_PAUSE_STATE		3
50 #define QUP_STATE_MASK		3
51 
52 #define QUP_STATE_VALID		BIT(2)
53 #define QUP_I2C_MAST_GEN	BIT(4)
54 
55 #define QUP_OPERATIONAL_RESET	0x000ff0
56 #define QUP_I2C_STATUS_RESET	0xfffffc
57 
58 /* QUP OPERATIONAL FLAGS */
59 #define QUP_I2C_NACK_FLAG	BIT(3)
60 #define QUP_OUT_NOT_EMPTY	BIT(4)
61 #define QUP_IN_NOT_EMPTY	BIT(5)
62 #define QUP_OUT_FULL		BIT(6)
63 #define QUP_OUT_SVC_FLAG	BIT(8)
64 #define QUP_IN_SVC_FLAG		BIT(9)
65 #define QUP_MX_OUTPUT_DONE	BIT(10)
66 #define QUP_MX_INPUT_DONE	BIT(11)
67 
68 /* I2C mini core related values */
69 #define QUP_CLOCK_AUTO_GATE	BIT(13)
70 #define I2C_MINI_CORE		(2 << 8)
71 #define I2C_N_VAL		15
72 /* Most significant word offset in FIFO port */
73 #define QUP_MSW_SHIFT		(I2C_N_VAL + 1)
74 
75 /* Packing/Unpacking words in FIFOs, and IO modes */
76 #define QUP_OUTPUT_BLK_MODE	(1 << 10)
77 #define QUP_INPUT_BLK_MODE	(1 << 12)
78 #define QUP_UNPACK_EN		BIT(14)
79 #define QUP_PACK_EN		BIT(15)
80 
81 #define QUP_REPACK_EN		(QUP_UNPACK_EN | QUP_PACK_EN)
82 
83 #define QUP_OUTPUT_BLOCK_SIZE(x)(((x) >> 0) & 0x03)
84 #define QUP_OUTPUT_FIFO_SIZE(x)	(((x) >> 2) & 0x07)
85 #define QUP_INPUT_BLOCK_SIZE(x)	(((x) >> 5) & 0x03)
86 #define QUP_INPUT_FIFO_SIZE(x)	(((x) >> 7) & 0x07)
87 
88 /* QUP tags */
89 #define QUP_TAG_START		(1 << 8)
90 #define QUP_TAG_DATA		(2 << 8)
91 #define QUP_TAG_STOP		(3 << 8)
92 #define QUP_TAG_REC		(4 << 8)
93 
94 /* Status, Error flags */
95 #define I2C_STATUS_WR_BUFFER_FULL	BIT(0)
96 #define I2C_STATUS_BUS_ACTIVE		BIT(8)
97 #define I2C_STATUS_ERROR_MASK		0x38000fc
98 #define QUP_STATUS_ERROR_FLAGS		0x7c
99 
100 #define QUP_READ_LIMIT			256
101 
102 struct qup_i2c_dev {
103 	struct device		*dev;
104 	void __iomem		*base;
105 	int			irq;
106 	struct clk		*clk;
107 	struct clk		*pclk;
108 	struct i2c_adapter	adap;
109 
110 	int			clk_ctl;
111 	int			out_fifo_sz;
112 	int			in_fifo_sz;
113 	int			out_blk_sz;
114 	int			in_blk_sz;
115 
116 	unsigned long		one_byte_t;
117 
118 	struct i2c_msg		*msg;
119 	/* Current posion in user message buffer */
120 	int			pos;
121 	/* I2C protocol errors */
122 	u32			bus_err;
123 	/* QUP core errors */
124 	u32			qup_err;
125 
126 	struct completion	xfer;
127 };
128 
129 static irqreturn_t qup_i2c_interrupt(int irq, void *dev)
130 {
131 	struct qup_i2c_dev *qup = dev;
132 	u32 bus_err;
133 	u32 qup_err;
134 	u32 opflags;
135 
136 	bus_err = readl(qup->base + QUP_I2C_STATUS);
137 	qup_err = readl(qup->base + QUP_ERROR_FLAGS);
138 	opflags = readl(qup->base + QUP_OPERATIONAL);
139 
140 	if (!qup->msg) {
141 		/* Clear Error interrupt */
142 		writel(QUP_RESET_STATE, qup->base + QUP_STATE);
143 		return IRQ_HANDLED;
144 	}
145 
146 	bus_err &= I2C_STATUS_ERROR_MASK;
147 	qup_err &= QUP_STATUS_ERROR_FLAGS;
148 
149 	if (qup_err) {
150 		/* Clear Error interrupt */
151 		writel(qup_err, qup->base + QUP_ERROR_FLAGS);
152 		goto done;
153 	}
154 
155 	if (bus_err) {
156 		/* Clear Error interrupt */
157 		writel(QUP_RESET_STATE, qup->base + QUP_STATE);
158 		goto done;
159 	}
160 
161 	if (opflags & QUP_IN_SVC_FLAG)
162 		writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL);
163 
164 	if (opflags & QUP_OUT_SVC_FLAG)
165 		writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL);
166 
167 done:
168 	qup->qup_err = qup_err;
169 	qup->bus_err = bus_err;
170 	complete(&qup->xfer);
171 	return IRQ_HANDLED;
172 }
173 
174 static int qup_i2c_poll_state_mask(struct qup_i2c_dev *qup,
175 				   u32 req_state, u32 req_mask)
176 {
177 	int retries = 1;
178 	u32 state;
179 
180 	/*
181 	 * State transition takes 3 AHB clocks cycles + 3 I2C master clock
182 	 * cycles. So retry once after a 1uS delay.
183 	 */
184 	do {
185 		state = readl(qup->base + QUP_STATE);
186 
187 		if (state & QUP_STATE_VALID &&
188 		    (state & req_mask) == req_state)
189 			return 0;
190 
191 		udelay(1);
192 	} while (retries--);
193 
194 	return -ETIMEDOUT;
195 }
196 
197 static int qup_i2c_poll_state(struct qup_i2c_dev *qup, u32 req_state)
198 {
199 	return qup_i2c_poll_state_mask(qup, req_state, QUP_STATE_MASK);
200 }
201 
202 static int qup_i2c_poll_state_valid(struct qup_i2c_dev *qup)
203 {
204 	return qup_i2c_poll_state_mask(qup, 0, 0);
205 }
206 
207 static int qup_i2c_poll_state_i2c_master(struct qup_i2c_dev *qup)
208 {
209 	return qup_i2c_poll_state_mask(qup, QUP_I2C_MAST_GEN, QUP_I2C_MAST_GEN);
210 }
211 
212 static int qup_i2c_change_state(struct qup_i2c_dev *qup, u32 state)
213 {
214 	if (qup_i2c_poll_state_valid(qup) != 0)
215 		return -EIO;
216 
217 	writel(state, qup->base + QUP_STATE);
218 
219 	if (qup_i2c_poll_state(qup, state) != 0)
220 		return -EIO;
221 	return 0;
222 }
223 
224 static int qup_i2c_wait_writeready(struct qup_i2c_dev *qup)
225 {
226 	unsigned long timeout;
227 	u32 opflags;
228 	u32 status;
229 
230 	timeout = jiffies + HZ;
231 
232 	for (;;) {
233 		opflags = readl(qup->base + QUP_OPERATIONAL);
234 		status = readl(qup->base + QUP_I2C_STATUS);
235 
236 		if (!(opflags & QUP_OUT_NOT_EMPTY) &&
237 		    !(status & I2C_STATUS_BUS_ACTIVE))
238 			return 0;
239 
240 		if (time_after(jiffies, timeout))
241 			return -ETIMEDOUT;
242 
243 		usleep_range(qup->one_byte_t, qup->one_byte_t * 2);
244 	}
245 }
246 
247 static void qup_i2c_set_write_mode(struct qup_i2c_dev *qup, struct i2c_msg *msg)
248 {
249 	/* Number of entries to shift out, including the start */
250 	int total = msg->len + 1;
251 
252 	if (total < qup->out_fifo_sz) {
253 		/* FIFO mode */
254 		writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE);
255 		writel(total, qup->base + QUP_MX_WRITE_CNT);
256 	} else {
257 		/* BLOCK mode (transfer data on chunks) */
258 		writel(QUP_OUTPUT_BLK_MODE | QUP_REPACK_EN,
259 		       qup->base + QUP_IO_MODE);
260 		writel(total, qup->base + QUP_MX_OUTPUT_CNT);
261 	}
262 }
263 
264 static void qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg)
265 {
266 	u32 addr = msg->addr << 1;
267 	u32 qup_tag;
268 	u32 opflags;
269 	int idx;
270 	u32 val;
271 
272 	if (qup->pos == 0) {
273 		val = QUP_TAG_START | addr;
274 		idx = 1;
275 	} else {
276 		val = 0;
277 		idx = 0;
278 	}
279 
280 	while (qup->pos < msg->len) {
281 		/* Check that there's space in the FIFO for our pair */
282 		opflags = readl(qup->base + QUP_OPERATIONAL);
283 		if (opflags & QUP_OUT_FULL)
284 			break;
285 
286 		if (qup->pos == msg->len - 1)
287 			qup_tag = QUP_TAG_STOP;
288 		else
289 			qup_tag = QUP_TAG_DATA;
290 
291 		if (idx & 1)
292 			val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT;
293 		else
294 			val = qup_tag | msg->buf[qup->pos];
295 
296 		/* Write out the pair and the last odd value */
297 		if (idx & 1 || qup->pos == msg->len - 1)
298 			writel(val, qup->base + QUP_OUT_FIFO_BASE);
299 
300 		qup->pos++;
301 		idx++;
302 	}
303 }
304 
305 static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
306 {
307 	unsigned long left;
308 	int ret;
309 
310 	qup->msg = msg;
311 	qup->pos = 0;
312 
313 	enable_irq(qup->irq);
314 
315 	qup_i2c_set_write_mode(qup, msg);
316 
317 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
318 	if (ret)
319 		goto err;
320 
321 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
322 
323 	do {
324 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
325 		if (ret)
326 			goto err;
327 
328 		qup_i2c_issue_write(qup, msg);
329 
330 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
331 		if (ret)
332 			goto err;
333 
334 		left = wait_for_completion_timeout(&qup->xfer, HZ);
335 		if (!left) {
336 			writel(1, qup->base + QUP_SW_RESET);
337 			ret = -ETIMEDOUT;
338 			goto err;
339 		}
340 
341 		if (qup->bus_err || qup->qup_err) {
342 			if (qup->bus_err & QUP_I2C_NACK_FLAG)
343 				dev_err(qup->dev, "NACK from %x\n", msg->addr);
344 			ret = -EIO;
345 			goto err;
346 		}
347 	} while (qup->pos < msg->len);
348 
349 	/* Wait for the outstanding data in the fifo to drain */
350 	ret = qup_i2c_wait_writeready(qup);
351 
352 err:
353 	disable_irq(qup->irq);
354 	qup->msg = NULL;
355 
356 	return ret;
357 }
358 
359 static void qup_i2c_set_read_mode(struct qup_i2c_dev *qup, int len)
360 {
361 	if (len < qup->in_fifo_sz) {
362 		/* FIFO mode */
363 		writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE);
364 		writel(len, qup->base + QUP_MX_READ_CNT);
365 	} else {
366 		/* BLOCK mode (transfer data on chunks) */
367 		writel(QUP_INPUT_BLK_MODE | QUP_REPACK_EN,
368 		       qup->base + QUP_IO_MODE);
369 		writel(len, qup->base + QUP_MX_INPUT_CNT);
370 	}
371 }
372 
373 static void qup_i2c_issue_read(struct qup_i2c_dev *qup, struct i2c_msg *msg)
374 {
375 	u32 addr, len, val;
376 
377 	addr = (msg->addr << 1) | 1;
378 
379 	/* 0 is used to specify a length 256 (QUP_READ_LIMIT) */
380 	len = (msg->len == QUP_READ_LIMIT) ? 0 : msg->len;
381 
382 	val = ((QUP_TAG_REC | len) << QUP_MSW_SHIFT) | QUP_TAG_START | addr;
383 	writel(val, qup->base + QUP_OUT_FIFO_BASE);
384 }
385 
386 
387 static void qup_i2c_read_fifo(struct qup_i2c_dev *qup, struct i2c_msg *msg)
388 {
389 	u32 opflags;
390 	u32 val = 0;
391 	int idx;
392 
393 	for (idx = 0; qup->pos < msg->len; idx++) {
394 		if ((idx & 1) == 0) {
395 			/* Check that FIFO have data */
396 			opflags = readl(qup->base + QUP_OPERATIONAL);
397 			if (!(opflags & QUP_IN_NOT_EMPTY))
398 				break;
399 
400 			/* Reading 2 words at time */
401 			val = readl(qup->base + QUP_IN_FIFO_BASE);
402 
403 			msg->buf[qup->pos++] = val & 0xFF;
404 		} else {
405 			msg->buf[qup->pos++] = val >> QUP_MSW_SHIFT;
406 		}
407 	}
408 }
409 
410 static int qup_i2c_read_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
411 {
412 	unsigned long left;
413 	int ret;
414 
415 	/*
416 	 * The QUP block will issue a NACK and STOP on the bus when reaching
417 	 * the end of the read, the length of the read is specified as one byte
418 	 * which limits the possible read to 256 (QUP_READ_LIMIT) bytes.
419 	 */
420 	if (msg->len > QUP_READ_LIMIT) {
421 		dev_err(qup->dev, "HW not capable of reads over %d bytes\n",
422 			QUP_READ_LIMIT);
423 		return -EINVAL;
424 	}
425 
426 	qup->msg = msg;
427 	qup->pos  = 0;
428 
429 	enable_irq(qup->irq);
430 
431 	qup_i2c_set_read_mode(qup, msg->len);
432 
433 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
434 	if (ret)
435 		goto err;
436 
437 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
438 
439 	ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
440 	if (ret)
441 		goto err;
442 
443 	qup_i2c_issue_read(qup, msg);
444 
445 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
446 	if (ret)
447 		goto err;
448 
449 	do {
450 		left = wait_for_completion_timeout(&qup->xfer, HZ);
451 		if (!left) {
452 			writel(1, qup->base + QUP_SW_RESET);
453 			ret = -ETIMEDOUT;
454 			goto err;
455 		}
456 
457 		if (qup->bus_err || qup->qup_err) {
458 			if (qup->bus_err & QUP_I2C_NACK_FLAG)
459 				dev_err(qup->dev, "NACK from %x\n", msg->addr);
460 			ret = -EIO;
461 			goto err;
462 		}
463 
464 		qup_i2c_read_fifo(qup, msg);
465 	} while (qup->pos < msg->len);
466 
467 err:
468 	disable_irq(qup->irq);
469 	qup->msg = NULL;
470 
471 	return ret;
472 }
473 
474 static int qup_i2c_xfer(struct i2c_adapter *adap,
475 			struct i2c_msg msgs[],
476 			int num)
477 {
478 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
479 	int ret, idx;
480 
481 	ret = pm_runtime_get_sync(qup->dev);
482 	if (ret)
483 		goto out;
484 
485 	writel(1, qup->base + QUP_SW_RESET);
486 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
487 	if (ret)
488 		goto out;
489 
490 	/* Configure QUP as I2C mini core */
491 	writel(I2C_MINI_CORE | I2C_N_VAL, qup->base + QUP_CONFIG);
492 
493 	for (idx = 0; idx < num; idx++) {
494 		if (msgs[idx].len == 0) {
495 			ret = -EINVAL;
496 			goto out;
497 		}
498 
499 		if (qup_i2c_poll_state_i2c_master(qup)) {
500 			ret = -EIO;
501 			goto out;
502 		}
503 
504 		if (msgs[idx].flags & I2C_M_RD)
505 			ret = qup_i2c_read_one(qup, &msgs[idx]);
506 		else
507 			ret = qup_i2c_write_one(qup, &msgs[idx]);
508 
509 		if (ret)
510 			break;
511 
512 		ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
513 		if (ret)
514 			break;
515 	}
516 
517 	if (ret == 0)
518 		ret = num;
519 out:
520 
521 	pm_runtime_mark_last_busy(qup->dev);
522 	pm_runtime_put_autosuspend(qup->dev);
523 
524 	return ret;
525 }
526 
527 static u32 qup_i2c_func(struct i2c_adapter *adap)
528 {
529 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
530 }
531 
532 static const struct i2c_algorithm qup_i2c_algo = {
533 	.master_xfer	= qup_i2c_xfer,
534 	.functionality	= qup_i2c_func,
535 };
536 
537 static void qup_i2c_enable_clocks(struct qup_i2c_dev *qup)
538 {
539 	clk_prepare_enable(qup->clk);
540 	clk_prepare_enable(qup->pclk);
541 }
542 
543 static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup)
544 {
545 	u32 config;
546 
547 	qup_i2c_change_state(qup, QUP_RESET_STATE);
548 	clk_disable_unprepare(qup->clk);
549 	config = readl(qup->base + QUP_CONFIG);
550 	config |= QUP_CLOCK_AUTO_GATE;
551 	writel(config, qup->base + QUP_CONFIG);
552 	clk_disable_unprepare(qup->pclk);
553 }
554 
555 static int qup_i2c_probe(struct platform_device *pdev)
556 {
557 	static const int blk_sizes[] = {4, 16, 32};
558 	struct device_node *node = pdev->dev.of_node;
559 	struct qup_i2c_dev *qup;
560 	unsigned long one_bit_t;
561 	struct resource *res;
562 	u32 io_mode, hw_ver, size;
563 	int ret, fs_div, hs_div;
564 	int src_clk_freq;
565 	u32 clk_freq = 100000;
566 
567 	qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);
568 	if (!qup)
569 		return -ENOMEM;
570 
571 	qup->dev = &pdev->dev;
572 	init_completion(&qup->xfer);
573 	platform_set_drvdata(pdev, qup);
574 
575 	of_property_read_u32(node, "clock-frequency", &clk_freq);
576 
577 	/* We support frequencies up to FAST Mode (400KHz) */
578 	if (!clk_freq || clk_freq > 400000) {
579 		dev_err(qup->dev, "clock frequency not supported %d\n",
580 			clk_freq);
581 		return -EINVAL;
582 	}
583 
584 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
585 	qup->base = devm_ioremap_resource(qup->dev, res);
586 	if (IS_ERR(qup->base))
587 		return PTR_ERR(qup->base);
588 
589 	qup->irq = platform_get_irq(pdev, 0);
590 	if (qup->irq < 0) {
591 		dev_err(qup->dev, "No IRQ defined\n");
592 		return qup->irq;
593 	}
594 
595 	qup->clk = devm_clk_get(qup->dev, "core");
596 	if (IS_ERR(qup->clk)) {
597 		dev_err(qup->dev, "Could not get core clock\n");
598 		return PTR_ERR(qup->clk);
599 	}
600 
601 	qup->pclk = devm_clk_get(qup->dev, "iface");
602 	if (IS_ERR(qup->pclk)) {
603 		dev_err(qup->dev, "Could not get iface clock\n");
604 		return PTR_ERR(qup->pclk);
605 	}
606 
607 	qup_i2c_enable_clocks(qup);
608 
609 	/*
610 	 * Bootloaders might leave a pending interrupt on certain QUP's,
611 	 * so we reset the core before registering for interrupts.
612 	 */
613 	writel(1, qup->base + QUP_SW_RESET);
614 	ret = qup_i2c_poll_state_valid(qup);
615 	if (ret)
616 		goto fail;
617 
618 	ret = devm_request_irq(qup->dev, qup->irq, qup_i2c_interrupt,
619 			       IRQF_TRIGGER_HIGH, "i2c_qup", qup);
620 	if (ret) {
621 		dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq);
622 		goto fail;
623 	}
624 	disable_irq(qup->irq);
625 
626 	hw_ver = readl(qup->base + QUP_HW_VERSION);
627 	dev_dbg(qup->dev, "Revision %x\n", hw_ver);
628 
629 	io_mode = readl(qup->base + QUP_IO_MODE);
630 
631 	/*
632 	 * The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag'
633 	 * associated with each byte written/received
634 	 */
635 	size = QUP_OUTPUT_BLOCK_SIZE(io_mode);
636 	if (size >= ARRAY_SIZE(blk_sizes))
637 		return -EIO;
638 	qup->out_blk_sz = blk_sizes[size] / 2;
639 
640 	size = QUP_INPUT_BLOCK_SIZE(io_mode);
641 	if (size >= ARRAY_SIZE(blk_sizes))
642 		return -EIO;
643 	qup->in_blk_sz = blk_sizes[size] / 2;
644 
645 	size = QUP_OUTPUT_FIFO_SIZE(io_mode);
646 	qup->out_fifo_sz = qup->out_blk_sz * (2 << size);
647 
648 	size = QUP_INPUT_FIFO_SIZE(io_mode);
649 	qup->in_fifo_sz = qup->in_blk_sz * (2 << size);
650 
651 	src_clk_freq = clk_get_rate(qup->clk);
652 	fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
653 	hs_div = 3;
654 	qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff);
655 
656 	/*
657 	 * Time it takes for a byte to be clocked out on the bus.
658 	 * Each byte takes 9 clock cycles (8 bits + 1 ack).
659 	 */
660 	one_bit_t = (USEC_PER_SEC / clk_freq) + 1;
661 	qup->one_byte_t = one_bit_t * 9;
662 
663 	dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n",
664 		qup->in_blk_sz, qup->in_fifo_sz,
665 		qup->out_blk_sz, qup->out_fifo_sz);
666 
667 	i2c_set_adapdata(&qup->adap, qup);
668 	qup->adap.algo = &qup_i2c_algo;
669 	qup->adap.dev.parent = qup->dev;
670 	qup->adap.dev.of_node = pdev->dev.of_node;
671 	strlcpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name));
672 
673 	ret = i2c_add_adapter(&qup->adap);
674 	if (ret)
675 		goto fail;
676 
677 	pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC);
678 	pm_runtime_use_autosuspend(qup->dev);
679 	pm_runtime_set_active(qup->dev);
680 	pm_runtime_enable(qup->dev);
681 	return 0;
682 
683 fail:
684 	qup_i2c_disable_clocks(qup);
685 	return ret;
686 }
687 
688 static int qup_i2c_remove(struct platform_device *pdev)
689 {
690 	struct qup_i2c_dev *qup = platform_get_drvdata(pdev);
691 
692 	disable_irq(qup->irq);
693 	qup_i2c_disable_clocks(qup);
694 	i2c_del_adapter(&qup->adap);
695 	pm_runtime_disable(qup->dev);
696 	pm_runtime_set_suspended(qup->dev);
697 	return 0;
698 }
699 
700 #ifdef CONFIG_PM
701 static int qup_i2c_pm_suspend_runtime(struct device *device)
702 {
703 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
704 
705 	dev_dbg(device, "pm_runtime: suspending...\n");
706 	qup_i2c_disable_clocks(qup);
707 	return 0;
708 }
709 
710 static int qup_i2c_pm_resume_runtime(struct device *device)
711 {
712 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
713 
714 	dev_dbg(device, "pm_runtime: resuming...\n");
715 	qup_i2c_enable_clocks(qup);
716 	return 0;
717 }
718 #endif
719 
720 #ifdef CONFIG_PM_SLEEP
721 static int qup_i2c_suspend(struct device *device)
722 {
723 	qup_i2c_pm_suspend_runtime(device);
724 	return 0;
725 }
726 
727 static int qup_i2c_resume(struct device *device)
728 {
729 	qup_i2c_pm_resume_runtime(device);
730 	pm_runtime_mark_last_busy(device);
731 	pm_request_autosuspend(device);
732 	return 0;
733 }
734 #endif
735 
736 static const struct dev_pm_ops qup_i2c_qup_pm_ops = {
737 	SET_SYSTEM_SLEEP_PM_OPS(
738 		qup_i2c_suspend,
739 		qup_i2c_resume)
740 	SET_RUNTIME_PM_OPS(
741 		qup_i2c_pm_suspend_runtime,
742 		qup_i2c_pm_resume_runtime,
743 		NULL)
744 };
745 
746 static const struct of_device_id qup_i2c_dt_match[] = {
747 	{ .compatible = "qcom,i2c-qup-v1.1.1" },
748 	{ .compatible = "qcom,i2c-qup-v2.1.1" },
749 	{ .compatible = "qcom,i2c-qup-v2.2.1" },
750 	{}
751 };
752 MODULE_DEVICE_TABLE(of, qup_i2c_dt_match);
753 
754 static struct platform_driver qup_i2c_driver = {
755 	.probe  = qup_i2c_probe,
756 	.remove = qup_i2c_remove,
757 	.driver = {
758 		.name = "i2c_qup",
759 		.owner = THIS_MODULE,
760 		.pm = &qup_i2c_qup_pm_ops,
761 		.of_match_table = qup_i2c_dt_match,
762 	},
763 };
764 
765 module_platform_driver(qup_i2c_driver);
766 
767 MODULE_LICENSE("GPL v2");
768 MODULE_ALIAS("platform:i2c_qup");
769