xref: /openbmc/linux/drivers/i2c/busses/i2c-xlp9xx.c (revision 703e7713)
1 /*
2  * Copyright (c) 2003-2015 Broadcom Corporation
3  *
4  * This file is licensed under the terms of the GNU General Public
5  * License version 2. This program is licensed "as is" without any
6  * warranty of any kind, whether express or implied.
7  */
8 
9 #include <linux/acpi.h>
10 #include <linux/clk.h>
11 #include <linux/completion.h>
12 #include <linux/i2c.h>
13 #include <linux/i2c-smbus.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/delay.h>
21 
22 #define XLP9XX_I2C_DIV			0x0
23 #define XLP9XX_I2C_CTRL			0x1
24 #define XLP9XX_I2C_CMD			0x2
25 #define XLP9XX_I2C_STATUS		0x3
26 #define XLP9XX_I2C_MTXFIFO		0x4
27 #define XLP9XX_I2C_MRXFIFO		0x5
28 #define XLP9XX_I2C_MFIFOCTRL		0x6
29 #define XLP9XX_I2C_STXFIFO		0x7
30 #define XLP9XX_I2C_SRXFIFO		0x8
31 #define XLP9XX_I2C_SFIFOCTRL		0x9
32 #define XLP9XX_I2C_SLAVEADDR		0xA
33 #define XLP9XX_I2C_OWNADDR		0xB
34 #define XLP9XX_I2C_FIFOWCNT		0xC
35 #define XLP9XX_I2C_INTEN		0xD
36 #define XLP9XX_I2C_INTST		0xE
37 #define XLP9XX_I2C_WAITCNT		0xF
38 #define XLP9XX_I2C_TIMEOUT		0X10
39 #define XLP9XX_I2C_GENCALLADDR		0x11
40 
41 #define XLP9XX_I2C_STATUS_BUSY		BIT(0)
42 
43 #define XLP9XX_I2C_CMD_START		BIT(7)
44 #define XLP9XX_I2C_CMD_STOP		BIT(6)
45 #define XLP9XX_I2C_CMD_READ		BIT(5)
46 #define XLP9XX_I2C_CMD_WRITE		BIT(4)
47 #define XLP9XX_I2C_CMD_ACK		BIT(3)
48 
49 #define XLP9XX_I2C_CTRL_MCTLEN_SHIFT	16
50 #define XLP9XX_I2C_CTRL_MCTLEN_MASK	0xffff0000
51 #define XLP9XX_I2C_CTRL_RST		BIT(8)
52 #define XLP9XX_I2C_CTRL_EN		BIT(6)
53 #define XLP9XX_I2C_CTRL_MASTER		BIT(4)
54 #define XLP9XX_I2C_CTRL_FIFORD		BIT(1)
55 #define XLP9XX_I2C_CTRL_ADDMODE		BIT(0)
56 
57 #define XLP9XX_I2C_INTEN_NACKADDR	BIT(25)
58 #define XLP9XX_I2C_INTEN_SADDR		BIT(13)
59 #define XLP9XX_I2C_INTEN_DATADONE	BIT(12)
60 #define XLP9XX_I2C_INTEN_ARLOST		BIT(11)
61 #define XLP9XX_I2C_INTEN_MFIFOFULL	BIT(4)
62 #define XLP9XX_I2C_INTEN_MFIFOEMTY	BIT(3)
63 #define XLP9XX_I2C_INTEN_MFIFOHI	BIT(2)
64 #define XLP9XX_I2C_INTEN_BUSERR		BIT(0)
65 
66 #define XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT		8
67 #define XLP9XX_I2C_MFIFOCTRL_LOTH_SHIFT		0
68 #define XLP9XX_I2C_MFIFOCTRL_RST		BIT(16)
69 
70 #define XLP9XX_I2C_SLAVEADDR_RW			BIT(0)
71 #define XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT		1
72 
73 #define XLP9XX_I2C_IP_CLK_FREQ		133000000UL
74 #define XLP9XX_I2C_FIFO_SIZE		0x80U
75 #define XLP9XX_I2C_TIMEOUT_MS		1000
76 #define XLP9XX_I2C_BUSY_TIMEOUT		50
77 
78 #define XLP9XX_I2C_FIFO_WCNT_MASK	0xff
79 #define XLP9XX_I2C_STATUS_ERRMASK	(XLP9XX_I2C_INTEN_ARLOST | \
80 			XLP9XX_I2C_INTEN_NACKADDR | XLP9XX_I2C_INTEN_BUSERR)
81 
82 struct xlp9xx_i2c_dev {
83 	struct device *dev;
84 	struct i2c_adapter adapter;
85 	struct completion msg_complete;
86 	struct i2c_smbus_alert_setup alert_data;
87 	struct i2c_client *ara;
88 	int irq;
89 	bool msg_read;
90 	bool len_recv;
91 	bool client_pec;
92 	u32 __iomem *base;
93 	u32 msg_buf_remaining;
94 	u32 msg_len;
95 	u32 ip_clk_hz;
96 	u32 clk_hz;
97 	u32 msg_err;
98 	u8 *msg_buf;
99 };
100 
101 static inline void xlp9xx_write_i2c_reg(struct xlp9xx_i2c_dev *priv,
102 					unsigned long reg, u32 val)
103 {
104 	writel(val, priv->base + reg);
105 }
106 
107 static inline u32 xlp9xx_read_i2c_reg(struct xlp9xx_i2c_dev *priv,
108 				      unsigned long reg)
109 {
110 	return readl(priv->base + reg);
111 }
112 
113 static void xlp9xx_i2c_mask_irq(struct xlp9xx_i2c_dev *priv, u32 mask)
114 {
115 	u32 inten;
116 
117 	inten = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTEN) & ~mask;
118 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, inten);
119 }
120 
121 static void xlp9xx_i2c_unmask_irq(struct xlp9xx_i2c_dev *priv, u32 mask)
122 {
123 	u32 inten;
124 
125 	inten = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTEN) | mask;
126 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, inten);
127 }
128 
129 static void xlp9xx_i2c_update_rx_fifo_thres(struct xlp9xx_i2c_dev *priv)
130 {
131 	u32 thres;
132 
133 	if (priv->len_recv)
134 		/* interrupt after the first read to examine
135 		 * the length byte before proceeding further
136 		 */
137 		thres = 1;
138 	else if (priv->msg_buf_remaining > XLP9XX_I2C_FIFO_SIZE)
139 		thres = XLP9XX_I2C_FIFO_SIZE;
140 	else
141 		thres = priv->msg_buf_remaining;
142 
143 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL,
144 			     thres << XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT);
145 }
146 
147 static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev *priv)
148 {
149 	u32 len, i;
150 	u8 *buf = priv->msg_buf;
151 
152 	len = min(priv->msg_buf_remaining, XLP9XX_I2C_FIFO_SIZE);
153 	for (i = 0; i < len; i++)
154 		xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MTXFIFO, buf[i]);
155 	priv->msg_buf_remaining -= len;
156 	priv->msg_buf += len;
157 }
158 
159 static void xlp9xx_i2c_update_rlen(struct xlp9xx_i2c_dev *priv)
160 {
161 	u32 val, len;
162 
163 	/*
164 	 * Update receive length. Re-read len to get the latest value,
165 	 * and then add 4 to have a minimum value that can be safely
166 	 * written. This is to account for the byte read above, the
167 	 * transfer in progress and any delays in the register I/O
168 	 */
169 	val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL);
170 	len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) &
171 				  XLP9XX_I2C_FIFO_WCNT_MASK;
172 	len = max_t(u32, priv->msg_len, len + 4);
173 	if (len >= I2C_SMBUS_BLOCK_MAX + 2)
174 		return;
175 	val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) |
176 			(len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
177 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val);
178 }
179 
180 static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv)
181 {
182 	u32 len, i;
183 	u8 rlen, *buf = priv->msg_buf;
184 
185 	len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) &
186 				  XLP9XX_I2C_FIFO_WCNT_MASK;
187 	if (!len)
188 		return;
189 	if (priv->len_recv) {
190 		/* read length byte */
191 		rlen = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);
192 
193 		/*
194 		 * We expect at least 2 interrupts for I2C_M_RECV_LEN
195 		 * transactions. The length is updated during the first
196 		 * interrupt, and the buffer contents are only copied
197 		 * during subsequent interrupts. If in case the interrupts
198 		 * get merged we would complete the transaction without
199 		 * copying out the bytes from RX fifo. To avoid this now we
200 		 * drain the fifo as and when data is available.
201 		 * We drained the rlen byte already, decrement total length
202 		 * by one.
203 		 */
204 
205 		len--;
206 		if (rlen > I2C_SMBUS_BLOCK_MAX || rlen == 0) {
207 			rlen = 0;	/*abort transfer */
208 			priv->msg_buf_remaining = 0;
209 			priv->msg_len = 0;
210 			xlp9xx_i2c_update_rlen(priv);
211 			return;
212 		}
213 
214 		*buf++ = rlen;
215 		if (priv->client_pec)
216 			++rlen; /* account for error check byte */
217 		/* update remaining bytes and message length */
218 		priv->msg_buf_remaining = rlen;
219 		priv->msg_len = rlen + 1;
220 		xlp9xx_i2c_update_rlen(priv);
221 		priv->len_recv = false;
222 	}
223 
224 	len = min(priv->msg_buf_remaining, len);
225 	for (i = 0; i < len; i++, buf++)
226 		*buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);
227 
228 	priv->msg_buf_remaining -= len;
229 	priv->msg_buf = buf;
230 
231 	if (priv->msg_buf_remaining)
232 		xlp9xx_i2c_update_rx_fifo_thres(priv);
233 }
234 
235 static irqreturn_t xlp9xx_i2c_isr(int irq, void *dev_id)
236 {
237 	struct xlp9xx_i2c_dev *priv = dev_id;
238 	u32 status;
239 
240 	status = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTST);
241 	if (status == 0)
242 		return IRQ_NONE;
243 
244 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTST, status);
245 	if (status & XLP9XX_I2C_STATUS_ERRMASK) {
246 		priv->msg_err = status;
247 		goto xfer_done;
248 	}
249 
250 	/* SADDR ACK for SMBUS_QUICK */
251 	if ((status & XLP9XX_I2C_INTEN_SADDR) && (priv->msg_len == 0))
252 		goto xfer_done;
253 
254 	if (!priv->msg_read) {
255 		if (status & XLP9XX_I2C_INTEN_MFIFOEMTY) {
256 			/* TX FIFO got empty, fill it up again */
257 			if (priv->msg_buf_remaining)
258 				xlp9xx_i2c_fill_tx_fifo(priv);
259 			else
260 				xlp9xx_i2c_mask_irq(priv,
261 						    XLP9XX_I2C_INTEN_MFIFOEMTY);
262 		}
263 	} else {
264 		if (status & (XLP9XX_I2C_INTEN_DATADONE |
265 			      XLP9XX_I2C_INTEN_MFIFOHI)) {
266 			/* data is in FIFO, read it */
267 			if (priv->msg_buf_remaining)
268 				xlp9xx_i2c_drain_rx_fifo(priv);
269 		}
270 	}
271 
272 	/* Transfer complete */
273 	if (status & XLP9XX_I2C_INTEN_DATADONE)
274 		goto xfer_done;
275 
276 	return IRQ_HANDLED;
277 
278 xfer_done:
279 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
280 	complete(&priv->msg_complete);
281 	return IRQ_HANDLED;
282 }
283 
284 static int xlp9xx_i2c_check_bus_status(struct xlp9xx_i2c_dev *priv)
285 {
286 	u32 status;
287 	u32 busy_timeout = XLP9XX_I2C_BUSY_TIMEOUT;
288 
289 	while (busy_timeout) {
290 		status = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_STATUS);
291 		if ((status & XLP9XX_I2C_STATUS_BUSY) == 0)
292 			break;
293 
294 		busy_timeout--;
295 		usleep_range(1000, 1100);
296 	}
297 
298 	if (!busy_timeout)
299 		return -EIO;
300 
301 	return 0;
302 }
303 
304 static int xlp9xx_i2c_init(struct xlp9xx_i2c_dev *priv)
305 {
306 	u32 prescale;
307 
308 	/*
309 	 * The controller uses 5 * SCL clock internally.
310 	 * So prescale value should be divided by 5.
311 	 */
312 	prescale = DIV_ROUND_UP(priv->ip_clk_hz, priv->clk_hz);
313 	prescale = ((prescale - 8) / 5) - 1;
314 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, XLP9XX_I2C_CTRL_RST);
315 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, XLP9XX_I2C_CTRL_EN |
316 			     XLP9XX_I2C_CTRL_MASTER);
317 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_DIV, prescale);
318 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
319 
320 	return 0;
321 }
322 
323 static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg,
324 			       int last_msg)
325 {
326 	unsigned long timeleft;
327 	u32 intr_mask, cmd, val, len;
328 
329 	priv->msg_buf = msg->buf;
330 	priv->msg_buf_remaining = priv->msg_len = msg->len;
331 	priv->msg_err = 0;
332 	priv->msg_read = (msg->flags & I2C_M_RD);
333 	reinit_completion(&priv->msg_complete);
334 
335 	/* Reset FIFO */
336 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL,
337 			     XLP9XX_I2C_MFIFOCTRL_RST);
338 
339 	/* set slave addr */
340 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_SLAVEADDR,
341 			     (msg->addr << XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT) |
342 			     (priv->msg_read ? XLP9XX_I2C_SLAVEADDR_RW : 0));
343 
344 	/* Build control word for transfer */
345 	val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL);
346 	if (!priv->msg_read)
347 		val &= ~XLP9XX_I2C_CTRL_FIFORD;
348 	else
349 		val |= XLP9XX_I2C_CTRL_FIFORD;	/* read */
350 
351 	if (msg->flags & I2C_M_TEN)
352 		val |= XLP9XX_I2C_CTRL_ADDMODE;	/* 10-bit address mode*/
353 	else
354 		val &= ~XLP9XX_I2C_CTRL_ADDMODE;
355 
356 	priv->len_recv = msg->flags & I2C_M_RECV_LEN;
357 	len = priv->len_recv ? I2C_SMBUS_BLOCK_MAX + 2 : msg->len;
358 	priv->client_pec = msg->flags & I2C_CLIENT_PEC;
359 
360 	/* set FIFO threshold if reading */
361 	if (priv->msg_read)
362 		xlp9xx_i2c_update_rx_fifo_thres(priv);
363 
364 	/* set data length to be transferred */
365 	val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) |
366 	      (len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
367 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val);
368 
369 	/* fill fifo during tx */
370 	if (!priv->msg_read)
371 		xlp9xx_i2c_fill_tx_fifo(priv);
372 
373 	/* set interrupt mask */
374 	intr_mask = (XLP9XX_I2C_INTEN_ARLOST | XLP9XX_I2C_INTEN_BUSERR |
375 		     XLP9XX_I2C_INTEN_NACKADDR | XLP9XX_I2C_INTEN_DATADONE);
376 
377 	if (priv->msg_read) {
378 		intr_mask |= XLP9XX_I2C_INTEN_MFIFOHI;
379 		if (msg->len == 0)
380 			intr_mask |= XLP9XX_I2C_INTEN_SADDR;
381 	} else {
382 		if (msg->len == 0)
383 			intr_mask |= XLP9XX_I2C_INTEN_SADDR;
384 		else
385 			intr_mask |= XLP9XX_I2C_INTEN_MFIFOEMTY;
386 	}
387 	xlp9xx_i2c_unmask_irq(priv, intr_mask);
388 
389 	/* set cmd reg */
390 	cmd = XLP9XX_I2C_CMD_START;
391 	if (msg->len)
392 		cmd |= (priv->msg_read ?
393 			XLP9XX_I2C_CMD_READ : XLP9XX_I2C_CMD_WRITE);
394 	if (last_msg)
395 		cmd |= XLP9XX_I2C_CMD_STOP;
396 
397 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CMD, cmd);
398 
399 	timeleft = msecs_to_jiffies(XLP9XX_I2C_TIMEOUT_MS);
400 	timeleft = wait_for_completion_timeout(&priv->msg_complete, timeleft);
401 
402 	if (priv->msg_err & XLP9XX_I2C_INTEN_BUSERR) {
403 		dev_dbg(priv->dev, "transfer error %x!\n", priv->msg_err);
404 		xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CMD, XLP9XX_I2C_CMD_STOP);
405 		return -EIO;
406 	} else if (priv->msg_err & XLP9XX_I2C_INTEN_NACKADDR) {
407 		return -ENXIO;
408 	}
409 
410 	if (timeleft == 0) {
411 		dev_dbg(priv->dev, "i2c transfer timed out!\n");
412 		xlp9xx_i2c_init(priv);
413 		return -ETIMEDOUT;
414 	}
415 
416 	/* update msg->len with actual received length */
417 	if (msg->flags & I2C_M_RECV_LEN) {
418 		if (!priv->msg_len)
419 			return -EPROTO;
420 		msg->len = priv->msg_len;
421 	}
422 	return 0;
423 }
424 
425 static int xlp9xx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
426 			   int num)
427 {
428 	int i, ret;
429 	struct xlp9xx_i2c_dev *priv = i2c_get_adapdata(adap);
430 
431 	ret = xlp9xx_i2c_check_bus_status(priv);
432 	if (ret) {
433 		xlp9xx_i2c_init(priv);
434 		ret = xlp9xx_i2c_check_bus_status(priv);
435 		if (ret)
436 			return ret;
437 	}
438 
439 	for (i = 0; i < num; i++) {
440 		ret = xlp9xx_i2c_xfer_msg(priv, &msgs[i], i == num - 1);
441 		if (ret != 0)
442 			return ret;
443 	}
444 
445 	return num;
446 }
447 
448 static u32 xlp9xx_i2c_functionality(struct i2c_adapter *adapter)
449 {
450 	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_READ_BLOCK_DATA |
451 			I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
452 }
453 
454 static const struct i2c_algorithm xlp9xx_i2c_algo = {
455 	.master_xfer = xlp9xx_i2c_xfer,
456 	.functionality = xlp9xx_i2c_functionality,
457 };
458 
459 static int xlp9xx_i2c_get_frequency(struct platform_device *pdev,
460 				    struct xlp9xx_i2c_dev *priv)
461 {
462 	struct clk *clk;
463 	u32 freq;
464 	int err;
465 
466 	clk = devm_clk_get(&pdev->dev, NULL);
467 	if (IS_ERR(clk)) {
468 		priv->ip_clk_hz = XLP9XX_I2C_IP_CLK_FREQ;
469 		dev_dbg(&pdev->dev, "using default input frequency %u\n",
470 			priv->ip_clk_hz);
471 	} else {
472 		priv->ip_clk_hz = clk_get_rate(clk);
473 	}
474 
475 	err = device_property_read_u32(&pdev->dev, "clock-frequency", &freq);
476 	if (err) {
477 		freq = I2C_MAX_STANDARD_MODE_FREQ;
478 		dev_dbg(&pdev->dev, "using default frequency %u\n", freq);
479 	} else if (freq == 0 || freq > I2C_MAX_FAST_MODE_FREQ) {
480 		dev_warn(&pdev->dev, "invalid frequency %u, using default\n",
481 			 freq);
482 		freq = I2C_MAX_STANDARD_MODE_FREQ;
483 	}
484 	priv->clk_hz = freq;
485 
486 	return 0;
487 }
488 
489 static int xlp9xx_i2c_smbus_setup(struct xlp9xx_i2c_dev *priv,
490 				  struct platform_device *pdev)
491 {
492 	struct i2c_client *ara;
493 
494 	if (!priv->alert_data.irq)
495 		return -EINVAL;
496 
497 	ara = i2c_new_smbus_alert_device(&priv->adapter, &priv->alert_data);
498 	if (IS_ERR(ara))
499 		return PTR_ERR(ara);
500 
501 	priv->ara = ara;
502 
503 	return 0;
504 }
505 
506 static int xlp9xx_i2c_probe(struct platform_device *pdev)
507 {
508 	struct xlp9xx_i2c_dev *priv;
509 	int err = 0;
510 
511 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
512 	if (!priv)
513 		return -ENOMEM;
514 
515 	priv->base = devm_platform_ioremap_resource(pdev, 0);
516 	if (IS_ERR(priv->base))
517 		return PTR_ERR(priv->base);
518 
519 	priv->irq = platform_get_irq(pdev, 0);
520 	if (priv->irq < 0)
521 		return priv->irq;
522 	/* SMBAlert irq */
523 	priv->alert_data.irq = platform_get_irq(pdev, 1);
524 	if (priv->alert_data.irq <= 0)
525 		priv->alert_data.irq = 0;
526 
527 	xlp9xx_i2c_get_frequency(pdev, priv);
528 	xlp9xx_i2c_init(priv);
529 
530 	err = devm_request_irq(&pdev->dev, priv->irq, xlp9xx_i2c_isr, 0,
531 			       pdev->name, priv);
532 	if (err) {
533 		dev_err(&pdev->dev, "IRQ request failed!\n");
534 		return err;
535 	}
536 
537 	init_completion(&priv->msg_complete);
538 	priv->adapter.dev.parent = &pdev->dev;
539 	priv->adapter.algo = &xlp9xx_i2c_algo;
540 	priv->adapter.class = I2C_CLASS_HWMON;
541 	ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
542 	priv->adapter.dev.of_node = pdev->dev.of_node;
543 	priv->dev = &pdev->dev;
544 
545 	snprintf(priv->adapter.name, sizeof(priv->adapter.name), "xlp9xx-i2c");
546 	i2c_set_adapdata(&priv->adapter, priv);
547 
548 	err = i2c_add_adapter(&priv->adapter);
549 	if (err)
550 		return err;
551 
552 	err = xlp9xx_i2c_smbus_setup(priv, pdev);
553 	if (err)
554 		dev_dbg(&pdev->dev, "No active SMBus alert %d\n", err);
555 
556 	platform_set_drvdata(pdev, priv);
557 	dev_dbg(&pdev->dev, "I2C bus:%d added\n", priv->adapter.nr);
558 
559 	return 0;
560 }
561 
562 static void xlp9xx_i2c_remove(struct platform_device *pdev)
563 {
564 	struct xlp9xx_i2c_dev *priv;
565 
566 	priv = platform_get_drvdata(pdev);
567 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
568 	synchronize_irq(priv->irq);
569 	i2c_del_adapter(&priv->adapter);
570 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, 0);
571 }
572 
573 #ifdef CONFIG_ACPI
574 static const struct acpi_device_id xlp9xx_i2c_acpi_ids[] = {
575 	{"BRCM9007", 0},
576 	{"CAV9007",  0},
577 	{}
578 };
579 MODULE_DEVICE_TABLE(acpi, xlp9xx_i2c_acpi_ids);
580 #endif
581 
582 static struct platform_driver xlp9xx_i2c_driver = {
583 	.probe = xlp9xx_i2c_probe,
584 	.remove_new = xlp9xx_i2c_remove,
585 	.driver = {
586 		.name = "xlp9xx-i2c",
587 		.acpi_match_table = ACPI_PTR(xlp9xx_i2c_acpi_ids),
588 	},
589 };
590 
591 module_platform_driver(xlp9xx_i2c_driver);
592 
593 MODULE_AUTHOR("Subhendu Sekhar Behera <sbehera@broadcom.com>");
594 MODULE_DESCRIPTION("XLP9XX/5XX I2C Bus Controller Driver");
595 MODULE_LICENSE("GPL v2");
596