xref: /linux/drivers/i2c/busses/i2c-k1.c (revision a6c23dac756b9541b33aa3bcd30f464df2879209)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2024-2025 Troy Mitchell <troymitchell988@gmail.com>
4  */
5 
6  #include <linux/clk.h>
7  #include <linux/i2c.h>
8  #include <linux/iopoll.h>
9  #include <linux/module.h>
10  #include <linux/of_address.h>
11  #include <linux/platform_device.h>
12 
13 /* spacemit i2c registers */
14 #define SPACEMIT_ICR		 0x0		/* Control register */
15 #define SPACEMIT_ISR		 0x4		/* Status register */
16 #define SPACEMIT_IDBR		 0xc		/* Data buffer register */
17 #define SPACEMIT_IBMR		 0x1c		/* Bus monitor register */
18 
19 /* SPACEMIT_ICR register fields */
20 #define SPACEMIT_CR_START        BIT(0)		/* start bit */
21 #define SPACEMIT_CR_STOP         BIT(1)		/* stop bit */
22 #define SPACEMIT_CR_ACKNAK       BIT(2)		/* send ACK(0) or NAK(1) */
23 #define SPACEMIT_CR_TB           BIT(3)		/* transfer byte bit */
24 /* Bits 4-7 are reserved */
25 #define SPACEMIT_CR_MODE_FAST    BIT(8)		/* bus mode (master operation) */
26 /* Bit 9 is reserved */
27 #define SPACEMIT_CR_UR           BIT(10)	/* unit reset */
28 /* Bits 11-12 are reserved */
29 #define SPACEMIT_CR_SCLE         BIT(13)	/* master clock enable */
30 #define SPACEMIT_CR_IUE          BIT(14)	/* unit enable */
31 /* Bits 15-17 are reserved */
32 #define SPACEMIT_CR_ALDIE        BIT(18)	/* enable arbitration interrupt */
33 #define SPACEMIT_CR_DTEIE        BIT(19)	/* enable TX interrupts */
34 #define SPACEMIT_CR_DRFIE        BIT(20)	/* enable RX interrupts */
35 #define SPACEMIT_CR_GCD          BIT(21)	/* general call disable */
36 #define SPACEMIT_CR_BEIE         BIT(22)	/* enable bus error ints */
37 /* Bits 23-24 are reserved */
38 #define SPACEMIT_CR_MSDIE        BIT(25)	/* master STOP detected int enable */
39 #define SPACEMIT_CR_MSDE         BIT(26)	/* master STOP detected enable */
40 #define SPACEMIT_CR_TXDONEIE     BIT(27)	/* transaction done int enable */
41 #define SPACEMIT_CR_TXEIE        BIT(28)	/* transmit FIFO empty int enable */
42 #define SPACEMIT_CR_RXHFIE       BIT(29)	/* receive FIFO half-full int enable */
43 #define SPACEMIT_CR_RXFIE        BIT(30)	/* receive FIFO full int enable */
44 #define SPACEMIT_CR_RXOVIE       BIT(31)	/* receive FIFO overrun int enable */
45 
46 #define SPACEMIT_I2C_INT_CTRL_MASK	(SPACEMIT_CR_ALDIE | SPACEMIT_CR_DTEIE | \
47 					 SPACEMIT_CR_DRFIE | SPACEMIT_CR_BEIE | \
48 					 SPACEMIT_CR_TXDONEIE | SPACEMIT_CR_TXEIE | \
49 					 SPACEMIT_CR_RXHFIE | SPACEMIT_CR_RXFIE | \
50 					 SPACEMIT_CR_RXOVIE | SPACEMIT_CR_MSDIE)
51 
52 /* SPACEMIT_ISR register fields */
53 /* Bits 0-13 are reserved */
54 #define SPACEMIT_SR_ACKNAK       BIT(14)	/* ACK/NACK status */
55 #define SPACEMIT_SR_UB           BIT(15)	/* unit busy */
56 #define SPACEMIT_SR_IBB          BIT(16)	/* i2c bus busy */
57 #define SPACEMIT_SR_EBB          BIT(17)	/* early bus busy */
58 #define SPACEMIT_SR_ALD          BIT(18)	/* arbitration loss detected */
59 #define SPACEMIT_SR_ITE          BIT(19)	/* TX buffer empty */
60 #define SPACEMIT_SR_IRF          BIT(20)	/* RX buffer full */
61 #define SPACEMIT_SR_GCAD         BIT(21)	/* general call address detected */
62 #define SPACEMIT_SR_BED          BIT(22)	/* bus error no ACK/NAK */
63 #define SPACEMIT_SR_SAD          BIT(23)	/* slave address detected */
64 #define SPACEMIT_SR_SSD          BIT(24)	/* slave stop detected */
65 /* Bit 25 is reserved */
66 #define SPACEMIT_SR_MSD          BIT(26)	/* master stop detected */
67 #define SPACEMIT_SR_TXDONE       BIT(27)	/* transaction done */
68 #define SPACEMIT_SR_TXE          BIT(28)	/* TX FIFO empty */
69 #define SPACEMIT_SR_RXHF         BIT(29)	/* RX FIFO half-full */
70 #define SPACEMIT_SR_RXF          BIT(30)	/* RX FIFO full */
71 #define SPACEMIT_SR_RXOV         BIT(31)	/* RX FIFO overrun */
72 
73 #define SPACEMIT_I2C_INT_STATUS_MASK	(SPACEMIT_SR_RXOV | SPACEMIT_SR_RXF | SPACEMIT_SR_RXHF | \
74 					SPACEMIT_SR_TXE | SPACEMIT_SR_TXDONE | SPACEMIT_SR_MSD | \
75 					SPACEMIT_SR_SSD | SPACEMIT_SR_SAD | SPACEMIT_SR_BED | \
76 					SPACEMIT_SR_GCAD | SPACEMIT_SR_IRF | SPACEMIT_SR_ITE | \
77 					SPACEMIT_SR_ALD)
78 
79 /* SPACEMIT_IBMR register fields */
80 #define SPACEMIT_BMR_SDA         BIT(0)		/* SDA line level */
81 #define SPACEMIT_BMR_SCL         BIT(1)		/* SCL line level */
82 
83 /* i2c bus recover timeout: us */
84 #define SPACEMIT_I2C_BUS_BUSY_TIMEOUT		100000
85 
86 #define SPACEMIT_I2C_MAX_STANDARD_MODE_FREQ	100000	/* Hz */
87 #define SPACEMIT_I2C_MAX_FAST_MODE_FREQ		400000	/* Hz */
88 
89 #define SPACEMIT_SR_ERR	(SPACEMIT_SR_BED | SPACEMIT_SR_RXOV | SPACEMIT_SR_ALD)
90 
91 enum spacemit_i2c_state {
92 	SPACEMIT_STATE_IDLE,
93 	SPACEMIT_STATE_START,
94 	SPACEMIT_STATE_READ,
95 	SPACEMIT_STATE_WRITE,
96 };
97 
98 /* i2c-spacemit driver's main struct */
99 struct spacemit_i2c_dev {
100 	struct device *dev;
101 	struct i2c_adapter adapt;
102 
103 	/* hardware resources */
104 	void __iomem *base;
105 	int irq;
106 	u32 clock_freq;
107 
108 	struct i2c_msg *msgs;
109 	u32 msg_num;
110 
111 	/* index of the current message being processed */
112 	u32 msg_idx;
113 	u8 *msg_buf;
114 	/* the number of unprocessed bytes remaining in the current message  */
115 	u32 unprocessed;
116 
117 	enum spacemit_i2c_state state;
118 	bool read;
119 	struct completion complete;
120 	u32 status;
121 };
122 
123 static void spacemit_i2c_enable(struct spacemit_i2c_dev *i2c)
124 {
125 	u32 val;
126 
127 	val = readl(i2c->base + SPACEMIT_ICR);
128 	val |= SPACEMIT_CR_IUE;
129 	writel(val, i2c->base + SPACEMIT_ICR);
130 }
131 
132 static void spacemit_i2c_disable(struct spacemit_i2c_dev *i2c)
133 {
134 	u32 val;
135 
136 	val = readl(i2c->base + SPACEMIT_ICR);
137 	val &= ~SPACEMIT_CR_IUE;
138 	writel(val, i2c->base + SPACEMIT_ICR);
139 }
140 
141 static void spacemit_i2c_reset(struct spacemit_i2c_dev *i2c)
142 {
143 	writel(SPACEMIT_CR_UR, i2c->base + SPACEMIT_ICR);
144 	udelay(5);
145 	writel(0, i2c->base + SPACEMIT_ICR);
146 }
147 
148 static int spacemit_i2c_handle_err(struct spacemit_i2c_dev *i2c)
149 {
150 	dev_dbg(i2c->dev, "i2c error status: 0x%08x\n", i2c->status);
151 
152 	if (i2c->status & (SPACEMIT_SR_BED | SPACEMIT_SR_ALD)) {
153 		spacemit_i2c_reset(i2c);
154 		return -EAGAIN;
155 	}
156 
157 	return i2c->status & SPACEMIT_SR_ACKNAK ? -ENXIO : -EIO;
158 }
159 
160 static void spacemit_i2c_conditionally_reset_bus(struct spacemit_i2c_dev *i2c)
161 {
162 	u32 status;
163 
164 	/* if bus is locked, reset unit. 0: locked */
165 	status = readl(i2c->base + SPACEMIT_IBMR);
166 	if ((status & SPACEMIT_BMR_SDA) && (status & SPACEMIT_BMR_SCL))
167 		return;
168 
169 	spacemit_i2c_reset(i2c);
170 	usleep_range(10, 20);
171 
172 	/* check scl status again */
173 	status = readl(i2c->base + SPACEMIT_IBMR);
174 	if (!(status & SPACEMIT_BMR_SCL))
175 		dev_warn_ratelimited(i2c->dev, "unit reset failed\n");
176 }
177 
178 static int spacemit_i2c_wait_bus_idle(struct spacemit_i2c_dev *i2c)
179 {
180 	int ret;
181 	u32 val;
182 
183 	val = readl(i2c->base + SPACEMIT_ISR);
184 	if (!(val & (SPACEMIT_SR_UB | SPACEMIT_SR_IBB)))
185 		return 0;
186 
187 	ret = readl_poll_timeout(i2c->base + SPACEMIT_ISR,
188 				 val, !(val & (SPACEMIT_SR_UB | SPACEMIT_SR_IBB)),
189 				 1500, SPACEMIT_I2C_BUS_BUSY_TIMEOUT);
190 	if (ret)
191 		spacemit_i2c_reset(i2c);
192 
193 	return ret;
194 }
195 
196 static void spacemit_i2c_check_bus_release(struct spacemit_i2c_dev *i2c)
197 {
198 	/* in case bus is not released after transfer completes */
199 	if (readl(i2c->base + SPACEMIT_ISR) & SPACEMIT_SR_EBB) {
200 		spacemit_i2c_conditionally_reset_bus(i2c);
201 		usleep_range(90, 150);
202 	}
203 }
204 
205 static void spacemit_i2c_init(struct spacemit_i2c_dev *i2c)
206 {
207 	u32 val;
208 
209 	/*
210 	 * Unmask interrupt bits for all xfer mode:
211 	 * bus error, arbitration loss detected.
212 	 * For transaction complete signal, we use master stop
213 	 * interrupt, so we don't need to unmask SPACEMIT_CR_TXDONEIE.
214 	 */
215 	val = SPACEMIT_CR_BEIE | SPACEMIT_CR_ALDIE;
216 
217 	/*
218 	 * Unmask interrupt bits for interrupt xfer mode:
219 	 * When IDBR receives a byte, an interrupt is triggered.
220 	 *
221 	 * For the tx empty interrupt, it will be enabled in the
222 	 * i2c_start function.
223 	 * Otherwise, it will cause an erroneous empty interrupt before i2c_start.
224 	 */
225 	val |= SPACEMIT_CR_DRFIE;
226 
227 	if (i2c->clock_freq == SPACEMIT_I2C_MAX_FAST_MODE_FREQ)
228 		val |= SPACEMIT_CR_MODE_FAST;
229 
230 	/* disable response to general call */
231 	val |= SPACEMIT_CR_GCD;
232 
233 	/* enable SCL clock output */
234 	val |= SPACEMIT_CR_SCLE;
235 
236 	/* enable master stop detected */
237 	val |= SPACEMIT_CR_MSDE | SPACEMIT_CR_MSDIE;
238 
239 	writel(val, i2c->base + SPACEMIT_ICR);
240 }
241 
242 static inline void
243 spacemit_i2c_clear_int_status(struct spacemit_i2c_dev *i2c, u32 mask)
244 {
245 	writel(mask & SPACEMIT_I2C_INT_STATUS_MASK, i2c->base + SPACEMIT_ISR);
246 }
247 
248 static void spacemit_i2c_start(struct spacemit_i2c_dev *i2c)
249 {
250 	u32 target_addr_rw, val;
251 	struct i2c_msg *cur_msg = i2c->msgs + i2c->msg_idx;
252 
253 	i2c->read = !!(cur_msg->flags & I2C_M_RD);
254 
255 	i2c->state = SPACEMIT_STATE_START;
256 
257 	target_addr_rw = (cur_msg->addr & 0x7f) << 1;
258 	if (cur_msg->flags & I2C_M_RD)
259 		target_addr_rw |= 1;
260 
261 	writel(target_addr_rw, i2c->base + SPACEMIT_IDBR);
262 
263 	/* send start pulse */
264 	val = readl(i2c->base + SPACEMIT_ICR);
265 	val &= ~SPACEMIT_CR_STOP;
266 	val |= SPACEMIT_CR_START | SPACEMIT_CR_TB | SPACEMIT_CR_DTEIE;
267 	writel(val, i2c->base + SPACEMIT_ICR);
268 }
269 
270 static void spacemit_i2c_stop(struct spacemit_i2c_dev *i2c)
271 {
272 	u32 val;
273 
274 	val = readl(i2c->base + SPACEMIT_ICR);
275 	val |= SPACEMIT_CR_STOP | SPACEMIT_CR_ALDIE | SPACEMIT_CR_TB;
276 
277 	if (i2c->read)
278 		val |= SPACEMIT_CR_ACKNAK;
279 
280 	writel(val, i2c->base + SPACEMIT_ICR);
281 }
282 
283 static int spacemit_i2c_xfer_msg(struct spacemit_i2c_dev *i2c)
284 {
285 	unsigned long time_left;
286 	struct i2c_msg *msg;
287 
288 	for (i2c->msg_idx = 0; i2c->msg_idx < i2c->msg_num; i2c->msg_idx++) {
289 		msg = &i2c->msgs[i2c->msg_idx];
290 		i2c->msg_buf = msg->buf;
291 		i2c->unprocessed = msg->len;
292 		i2c->status = 0;
293 
294 		reinit_completion(&i2c->complete);
295 
296 		spacemit_i2c_start(i2c);
297 
298 		time_left = wait_for_completion_timeout(&i2c->complete,
299 							i2c->adapt.timeout);
300 		if (!time_left) {
301 			dev_err(i2c->dev, "msg completion timeout\n");
302 			spacemit_i2c_conditionally_reset_bus(i2c);
303 			spacemit_i2c_reset(i2c);
304 			return -ETIMEDOUT;
305 		}
306 
307 		if (i2c->status & SPACEMIT_SR_ERR)
308 			return spacemit_i2c_handle_err(i2c);
309 	}
310 
311 	return 0;
312 }
313 
314 static bool spacemit_i2c_is_last_msg(struct spacemit_i2c_dev *i2c)
315 {
316 	if (i2c->msg_idx != i2c->msg_num - 1)
317 		return false;
318 
319 	if (i2c->read)
320 		return i2c->unprocessed == 1;
321 
322 	return !i2c->unprocessed;
323 }
324 
325 static void spacemit_i2c_handle_write(struct spacemit_i2c_dev *i2c)
326 {
327 	/* if transfer completes, SPACEMIT_ISR will handle it */
328 	if (i2c->status & SPACEMIT_SR_MSD)
329 		return;
330 
331 	if (i2c->unprocessed) {
332 		writel(*i2c->msg_buf++, i2c->base + SPACEMIT_IDBR);
333 		i2c->unprocessed--;
334 		return;
335 	}
336 
337 	/* SPACEMIT_STATE_IDLE avoids trigger next byte */
338 	i2c->state = SPACEMIT_STATE_IDLE;
339 	complete(&i2c->complete);
340 }
341 
342 static void spacemit_i2c_handle_read(struct spacemit_i2c_dev *i2c)
343 {
344 	if (i2c->unprocessed) {
345 		*i2c->msg_buf++ = readl(i2c->base + SPACEMIT_IDBR);
346 		i2c->unprocessed--;
347 	}
348 
349 	/* if transfer completes, SPACEMIT_ISR will handle it */
350 	if (i2c->status & (SPACEMIT_SR_MSD | SPACEMIT_SR_ACKNAK))
351 		return;
352 
353 	/* it has to append stop bit in icr that read last byte */
354 	if (i2c->unprocessed)
355 		return;
356 
357 	/* SPACEMIT_STATE_IDLE avoids trigger next byte */
358 	i2c->state = SPACEMIT_STATE_IDLE;
359 	complete(&i2c->complete);
360 }
361 
362 static void spacemit_i2c_handle_start(struct spacemit_i2c_dev *i2c)
363 {
364 	i2c->state = i2c->read ? SPACEMIT_STATE_READ : SPACEMIT_STATE_WRITE;
365 	if (i2c->state == SPACEMIT_STATE_WRITE)
366 		spacemit_i2c_handle_write(i2c);
367 }
368 
369 static void spacemit_i2c_err_check(struct spacemit_i2c_dev *i2c)
370 {
371 	u32 val;
372 
373 	/*
374 	 * Send transaction complete signal:
375 	 * error happens, detect master stop
376 	 */
377 	if (!(i2c->status & (SPACEMIT_SR_ERR | SPACEMIT_SR_MSD)))
378 		return;
379 
380 	/*
381 	 * Here the transaction is already done, we don't need any
382 	 * other interrupt signals from now, in case any interrupt
383 	 * happens before spacemit_i2c_xfer to disable irq and i2c unit,
384 	 * we mask all the interrupt signals and clear the interrupt
385 	 * status.
386 	 */
387 	val = readl(i2c->base + SPACEMIT_ICR);
388 	val &= ~SPACEMIT_I2C_INT_CTRL_MASK;
389 	writel(val, i2c->base + SPACEMIT_ICR);
390 
391 	spacemit_i2c_clear_int_status(i2c, SPACEMIT_I2C_INT_STATUS_MASK);
392 
393 	i2c->state = SPACEMIT_STATE_IDLE;
394 	complete(&i2c->complete);
395 }
396 
397 static irqreturn_t spacemit_i2c_irq_handler(int irq, void *devid)
398 {
399 	struct spacemit_i2c_dev *i2c = devid;
400 	u32 status, val;
401 
402 	status = readl(i2c->base + SPACEMIT_ISR);
403 	if (!status)
404 		return IRQ_HANDLED;
405 
406 	i2c->status = status;
407 
408 	spacemit_i2c_clear_int_status(i2c, status);
409 
410 	if (i2c->status & SPACEMIT_SR_ERR)
411 		goto err_out;
412 
413 	val = readl(i2c->base + SPACEMIT_ICR);
414 	val &= ~(SPACEMIT_CR_TB | SPACEMIT_CR_ACKNAK | SPACEMIT_CR_STOP | SPACEMIT_CR_START);
415 	writel(val, i2c->base + SPACEMIT_ICR);
416 
417 	switch (i2c->state) {
418 	case SPACEMIT_STATE_START:
419 		spacemit_i2c_handle_start(i2c);
420 		break;
421 	case SPACEMIT_STATE_READ:
422 		spacemit_i2c_handle_read(i2c);
423 		break;
424 	case SPACEMIT_STATE_WRITE:
425 		spacemit_i2c_handle_write(i2c);
426 		break;
427 	default:
428 		break;
429 	}
430 
431 	if (i2c->state != SPACEMIT_STATE_IDLE) {
432 		if (spacemit_i2c_is_last_msg(i2c)) {
433 			/* trigger next byte with stop */
434 			spacemit_i2c_stop(i2c);
435 		} else {
436 			/* trigger next byte */
437 			val |= SPACEMIT_CR_ALDIE | SPACEMIT_CR_TB;
438 			writel(val, i2c->base + SPACEMIT_ICR);
439 		}
440 	}
441 
442 err_out:
443 	spacemit_i2c_err_check(i2c);
444 	return IRQ_HANDLED;
445 }
446 
447 static void spacemit_i2c_calc_timeout(struct spacemit_i2c_dev *i2c)
448 {
449 	unsigned long timeout;
450 	int idx = 0, cnt = 0;
451 
452 	for (; idx < i2c->msg_num; idx++)
453 		cnt += (i2c->msgs + idx)->len + 1;
454 
455 	/*
456 	 * Multiply by 9 because each byte in I2C transmission requires
457 	 * 9 clock cycles: 8 bits of data plus 1 ACK/NACK bit.
458 	 */
459 	timeout = cnt * 9 * USEC_PER_SEC / i2c->clock_freq;
460 
461 	i2c->adapt.timeout = usecs_to_jiffies(timeout + USEC_PER_SEC / 10) / i2c->msg_num;
462 }
463 
464 static int spacemit_i2c_xfer(struct i2c_adapter *adapt, struct i2c_msg *msgs, int num)
465 {
466 	struct spacemit_i2c_dev *i2c = i2c_get_adapdata(adapt);
467 	int ret;
468 
469 	i2c->msgs = msgs;
470 	i2c->msg_num = num;
471 
472 	spacemit_i2c_calc_timeout(i2c);
473 
474 	spacemit_i2c_init(i2c);
475 
476 	spacemit_i2c_enable(i2c);
477 
478 	ret = spacemit_i2c_wait_bus_idle(i2c);
479 	if (!ret)
480 		ret = spacemit_i2c_xfer_msg(i2c);
481 	else if (ret < 0)
482 		dev_dbg(i2c->dev, "i2c transfer error: %d\n", ret);
483 	else
484 		spacemit_i2c_check_bus_release(i2c);
485 
486 	spacemit_i2c_disable(i2c);
487 
488 	if (ret == -ETIMEDOUT || ret == -EAGAIN)
489 		dev_err(i2c->dev, "i2c transfer failed, ret %d err 0x%lx\n",
490 			  ret, i2c->status & SPACEMIT_SR_ERR);
491 
492 	return ret < 0 ? ret : num;
493 }
494 
495 static u32 spacemit_i2c_func(struct i2c_adapter *adap)
496 {
497 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
498 }
499 
500 static const struct i2c_algorithm spacemit_i2c_algo = {
501 	.xfer = spacemit_i2c_xfer,
502 	.functionality = spacemit_i2c_func,
503 };
504 
505 static int spacemit_i2c_probe(struct platform_device *pdev)
506 {
507 	struct clk *clk;
508 	struct device *dev = &pdev->dev;
509 	struct device_node *of_node = pdev->dev.of_node;
510 	struct spacemit_i2c_dev *i2c;
511 	int ret;
512 
513 	i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
514 	if (!i2c)
515 		return -ENOMEM;
516 
517 	ret = of_property_read_u32(of_node, "clock-frequency", &i2c->clock_freq);
518 	if (ret && ret != -EINVAL)
519 		dev_warn(dev, "failed to read clock-frequency property: %d\n", ret);
520 
521 	/* For now, this driver doesn't support high-speed. */
522 	if (!i2c->clock_freq || i2c->clock_freq > SPACEMIT_I2C_MAX_FAST_MODE_FREQ) {
523 		dev_warn(dev, "unsupported clock frequency %u; using %u\n",
524 			 i2c->clock_freq, SPACEMIT_I2C_MAX_FAST_MODE_FREQ);
525 		i2c->clock_freq = SPACEMIT_I2C_MAX_FAST_MODE_FREQ;
526 	} else if (i2c->clock_freq < SPACEMIT_I2C_MAX_STANDARD_MODE_FREQ) {
527 		dev_warn(dev, "unsupported clock frequency %u; using %u\n",
528 			 i2c->clock_freq,  SPACEMIT_I2C_MAX_STANDARD_MODE_FREQ);
529 		i2c->clock_freq = SPACEMIT_I2C_MAX_STANDARD_MODE_FREQ;
530 	}
531 
532 	i2c->dev = &pdev->dev;
533 
534 	i2c->base = devm_platform_ioremap_resource(pdev, 0);
535 	if (IS_ERR(i2c->base))
536 		return dev_err_probe(dev, PTR_ERR(i2c->base), "failed to do ioremap");
537 
538 	i2c->irq = platform_get_irq(pdev, 0);
539 	if (i2c->irq < 0)
540 		return dev_err_probe(dev, i2c->irq, "failed to get irq resource");
541 
542 	ret = devm_request_irq(i2c->dev, i2c->irq, spacemit_i2c_irq_handler,
543 			       IRQF_NO_SUSPEND | IRQF_ONESHOT, dev_name(i2c->dev), i2c);
544 	if (ret)
545 		return dev_err_probe(dev, ret, "failed to request irq");
546 
547 	clk = devm_clk_get_enabled(dev, "func");
548 	if (IS_ERR(clk))
549 		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable func clock");
550 
551 	clk = devm_clk_get_enabled(dev, "bus");
552 	if (IS_ERR(clk))
553 		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable bus clock");
554 
555 	spacemit_i2c_reset(i2c);
556 
557 	i2c_set_adapdata(&i2c->adapt, i2c);
558 	i2c->adapt.owner = THIS_MODULE;
559 	i2c->adapt.algo = &spacemit_i2c_algo;
560 	i2c->adapt.dev.parent = i2c->dev;
561 	i2c->adapt.nr = pdev->id;
562 
563 	i2c->adapt.dev.of_node = of_node;
564 
565 	strscpy(i2c->adapt.name, "spacemit-i2c-adapter", sizeof(i2c->adapt.name));
566 
567 	init_completion(&i2c->complete);
568 
569 	platform_set_drvdata(pdev, i2c);
570 
571 	ret = i2c_add_numbered_adapter(&i2c->adapt);
572 	if (ret)
573 		return dev_err_probe(&pdev->dev, ret, "failed to add i2c adapter");
574 
575 	return 0;
576 }
577 
578 static void spacemit_i2c_remove(struct platform_device *pdev)
579 {
580 	struct spacemit_i2c_dev *i2c = platform_get_drvdata(pdev);
581 
582 	i2c_del_adapter(&i2c->adapt);
583 }
584 
585 static const struct of_device_id spacemit_i2c_of_match[] = {
586 	{ .compatible = "spacemit,k1-i2c", },
587 	{ /* sentinel */ }
588 };
589 MODULE_DEVICE_TABLE(of, spacemit_i2c_of_match);
590 
591 static struct platform_driver spacemit_i2c_driver = {
592 	.probe = spacemit_i2c_probe,
593 	.remove = spacemit_i2c_remove,
594 	.driver = {
595 		.name = "i2c-k1",
596 		.of_match_table = spacemit_i2c_of_match,
597 	},
598 };
599 module_platform_driver(spacemit_i2c_driver);
600 
601 MODULE_LICENSE("GPL");
602 MODULE_DESCRIPTION("I2C bus driver for SpacemiT K1 SoC");
603