xref: /openbmc/linux/drivers/i2c/busses/i2c-pnx.c (revision 384740dc)
1 /*
2  * Provides I2C support for Philips PNX010x/PNX4008 boards.
3  *
4  * Authors: Dennis Kovalev <dkovalev@ru.mvista.com>
5  *	    Vitaly Wool <vwool@ru.mvista.com>
6  *
7  * 2004-2006 (c) MontaVista Software, Inc. This file is licensed under
8  * the terms of the GNU General Public License version 2. This program
9  * is licensed "as is" without any warranty of any kind, whether express
10  * or implied.
11  */
12 
13 #include <linux/module.h>
14 #include <linux/interrupt.h>
15 #include <linux/ioport.h>
16 #include <linux/delay.h>
17 #include <linux/i2c.h>
18 #include <linux/timer.h>
19 #include <linux/completion.h>
20 #include <linux/platform_device.h>
21 #include <linux/i2c-pnx.h>
22 #include <mach/hardware.h>
23 #include <asm/irq.h>
24 #include <asm/uaccess.h>
25 
26 #define I2C_PNX_TIMEOUT		10 /* msec */
27 #define I2C_PNX_SPEED_KHZ	100
28 #define I2C_PNX_REGION_SIZE	0x100
29 #define PNX_DEFAULT_FREQ	13 /* MHz */
30 
31 static inline int wait_timeout(long timeout, struct i2c_pnx_algo_data *data)
32 {
33 	while (timeout > 0 &&
34 			(ioread32(I2C_REG_STS(data)) & mstatus_active)) {
35 		mdelay(1);
36 		timeout--;
37 	}
38 	return (timeout <= 0);
39 }
40 
41 static inline int wait_reset(long timeout, struct i2c_pnx_algo_data *data)
42 {
43 	while (timeout > 0 &&
44 			(ioread32(I2C_REG_CTL(data)) & mcntrl_reset)) {
45 		mdelay(1);
46 		timeout--;
47 	}
48 	return (timeout <= 0);
49 }
50 
51 static inline void i2c_pnx_arm_timer(struct i2c_adapter *adap)
52 {
53 	struct i2c_pnx_algo_data *data = adap->algo_data;
54 	struct timer_list *timer = &data->mif.timer;
55 	int expires = I2C_PNX_TIMEOUT / (1000 / HZ);
56 
57 	del_timer_sync(timer);
58 
59 	dev_dbg(&adap->dev, "Timer armed at %lu plus %u jiffies.\n",
60 		jiffies, expires);
61 
62 	timer->expires = jiffies + expires;
63 	timer->data = (unsigned long)adap;
64 
65 	add_timer(timer);
66 }
67 
68 /**
69  * i2c_pnx_start - start a device
70  * @slave_addr:		slave address
71  * @adap:		pointer to adapter structure
72  *
73  * Generate a START signal in the desired mode.
74  */
75 static int i2c_pnx_start(unsigned char slave_addr, struct i2c_adapter *adap)
76 {
77 	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
78 
79 	dev_dbg(&adap->dev, "%s(): addr 0x%x mode %d\n", __func__,
80 		slave_addr, alg_data->mif.mode);
81 
82 	/* Check for 7 bit slave addresses only */
83 	if (slave_addr & ~0x7f) {
84 		dev_err(&adap->dev, "%s: Invalid slave address %x. "
85 		       "Only 7-bit addresses are supported\n",
86 		       adap->name, slave_addr);
87 		return -EINVAL;
88 	}
89 
90 	/* First, make sure bus is idle */
91 	if (wait_timeout(I2C_PNX_TIMEOUT, alg_data)) {
92 		/* Somebody else is monopolizing the bus */
93 		dev_err(&adap->dev, "%s: Bus busy. Slave addr = %02x, "
94 		       "cntrl = %x, stat = %x\n",
95 		       adap->name, slave_addr,
96 		       ioread32(I2C_REG_CTL(alg_data)),
97 		       ioread32(I2C_REG_STS(alg_data)));
98 		return -EBUSY;
99 	} else if (ioread32(I2C_REG_STS(alg_data)) & mstatus_afi) {
100 		/* Sorry, we lost the bus */
101 		dev_err(&adap->dev, "%s: Arbitration failure. "
102 		       "Slave addr = %02x\n", adap->name, slave_addr);
103 		return -EIO;
104 	}
105 
106 	/*
107 	 * OK, I2C is enabled and we have the bus.
108 	 * Clear the current TDI and AFI status flags.
109 	 */
110 	iowrite32(ioread32(I2C_REG_STS(alg_data)) | mstatus_tdi | mstatus_afi,
111 		  I2C_REG_STS(alg_data));
112 
113 	dev_dbg(&adap->dev, "%s(): sending %#x\n", __func__,
114 		(slave_addr << 1) | start_bit | alg_data->mif.mode);
115 
116 	/* Write the slave address, START bit and R/W bit */
117 	iowrite32((slave_addr << 1) | start_bit | alg_data->mif.mode,
118 		  I2C_REG_TX(alg_data));
119 
120 	dev_dbg(&adap->dev, "%s(): exit\n", __func__);
121 
122 	return 0;
123 }
124 
125 /**
126  * i2c_pnx_stop - stop a device
127  * @adap:		pointer to I2C adapter structure
128  *
129  * Generate a STOP signal to terminate the master transaction.
130  */
131 static void i2c_pnx_stop(struct i2c_adapter *adap)
132 {
133 	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
134 	/* Only 1 msec max timeout due to interrupt context */
135 	long timeout = 1000;
136 
137 	dev_dbg(&adap->dev, "%s(): entering: stat = %04x.\n",
138 		__func__, ioread32(I2C_REG_STS(alg_data)));
139 
140 	/* Write a STOP bit to TX FIFO */
141 	iowrite32(0xff | stop_bit, I2C_REG_TX(alg_data));
142 
143 	/* Wait until the STOP is seen. */
144 	while (timeout > 0 &&
145 	       (ioread32(I2C_REG_STS(alg_data)) & mstatus_active)) {
146 		/* may be called from interrupt context */
147 		udelay(1);
148 		timeout--;
149 	}
150 
151 	dev_dbg(&adap->dev, "%s(): exiting: stat = %04x.\n",
152 		__func__, ioread32(I2C_REG_STS(alg_data)));
153 }
154 
155 /**
156  * i2c_pnx_master_xmit - transmit data to slave
157  * @adap:		pointer to I2C adapter structure
158  *
159  * Sends one byte of data to the slave
160  */
161 static int i2c_pnx_master_xmit(struct i2c_adapter *adap)
162 {
163 	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
164 	u32 val;
165 
166 	dev_dbg(&adap->dev, "%s(): entering: stat = %04x.\n",
167 		__func__, ioread32(I2C_REG_STS(alg_data)));
168 
169 	if (alg_data->mif.len > 0) {
170 		/* We still have something to talk about... */
171 		val = *alg_data->mif.buf++;
172 
173 		if (alg_data->mif.len == 1) {
174 			val |= stop_bit;
175 			if (!alg_data->last)
176 				val |= start_bit;
177 		}
178 
179 		alg_data->mif.len--;
180 		iowrite32(val, I2C_REG_TX(alg_data));
181 
182 		dev_dbg(&adap->dev, "%s(): xmit %#x [%d]\n", __func__,
183 			val, alg_data->mif.len + 1);
184 
185 		if (alg_data->mif.len == 0) {
186 			if (alg_data->last) {
187 				/* Wait until the STOP is seen. */
188 				if (wait_timeout(I2C_PNX_TIMEOUT, alg_data))
189 					dev_err(&adap->dev, "The bus is still "
190 						"active after timeout\n");
191 			}
192 			/* Disable master interrupts */
193 			iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
194 				~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
195 				  I2C_REG_CTL(alg_data));
196 
197 			del_timer_sync(&alg_data->mif.timer);
198 
199 			dev_dbg(&adap->dev, "%s(): Waking up xfer routine.\n",
200 				__func__);
201 
202 			complete(&alg_data->mif.complete);
203 		}
204 	} else if (alg_data->mif.len == 0) {
205 		/* zero-sized transfer */
206 		i2c_pnx_stop(adap);
207 
208 		/* Disable master interrupts. */
209 		iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
210 			~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
211 			  I2C_REG_CTL(alg_data));
212 
213 		/* Stop timer. */
214 		del_timer_sync(&alg_data->mif.timer);
215 		dev_dbg(&adap->dev, "%s(): Waking up xfer routine after "
216 			"zero-xfer.\n", __func__);
217 
218 		complete(&alg_data->mif.complete);
219 	}
220 
221 	dev_dbg(&adap->dev, "%s(): exiting: stat = %04x.\n",
222 		__func__, ioread32(I2C_REG_STS(alg_data)));
223 
224 	return 0;
225 }
226 
227 /**
228  * i2c_pnx_master_rcv - receive data from slave
229  * @adap:		pointer to I2C adapter structure
230  *
231  * Reads one byte data from the slave
232  */
233 static int i2c_pnx_master_rcv(struct i2c_adapter *adap)
234 {
235 	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
236 	unsigned int val = 0;
237 	u32 ctl = 0;
238 
239 	dev_dbg(&adap->dev, "%s(): entering: stat = %04x.\n",
240 		__func__, ioread32(I2C_REG_STS(alg_data)));
241 
242 	/* Check, whether there is already data,
243 	 * or we didn't 'ask' for it yet.
244 	 */
245 	if (ioread32(I2C_REG_STS(alg_data)) & mstatus_rfe) {
246 		dev_dbg(&adap->dev, "%s(): Write dummy data to fill "
247 			"Rx-fifo...\n", __func__);
248 
249 		if (alg_data->mif.len == 1) {
250 			/* Last byte, do not acknowledge next rcv. */
251 			val |= stop_bit;
252 			if (!alg_data->last)
253 				val |= start_bit;
254 
255 			/*
256 			 * Enable interrupt RFDAIE (data in Rx fifo),
257 			 * and disable DRMIE (need data for Tx)
258 			 */
259 			ctl = ioread32(I2C_REG_CTL(alg_data));
260 			ctl |= mcntrl_rffie | mcntrl_daie;
261 			ctl &= ~mcntrl_drmie;
262 			iowrite32(ctl, I2C_REG_CTL(alg_data));
263 		}
264 
265 		/*
266 		 * Now we'll 'ask' for data:
267 		 * For each byte we want to receive, we must
268 		 * write a (dummy) byte to the Tx-FIFO.
269 		 */
270 		iowrite32(val, I2C_REG_TX(alg_data));
271 
272 		return 0;
273 	}
274 
275 	/* Handle data. */
276 	if (alg_data->mif.len > 0) {
277 		val = ioread32(I2C_REG_RX(alg_data));
278 		*alg_data->mif.buf++ = (u8) (val & 0xff);
279 		dev_dbg(&adap->dev, "%s(): rcv 0x%x [%d]\n", __func__, val,
280 			alg_data->mif.len);
281 
282 		alg_data->mif.len--;
283 		if (alg_data->mif.len == 0) {
284 			if (alg_data->last)
285 				/* Wait until the STOP is seen. */
286 				if (wait_timeout(I2C_PNX_TIMEOUT, alg_data))
287 					dev_err(&adap->dev, "The bus is still "
288 						"active after timeout\n");
289 
290 			/* Disable master interrupts */
291 			ctl = ioread32(I2C_REG_CTL(alg_data));
292 			ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
293 				 mcntrl_drmie | mcntrl_daie);
294 			iowrite32(ctl, I2C_REG_CTL(alg_data));
295 
296 			/* Kill timer. */
297 			del_timer_sync(&alg_data->mif.timer);
298 			complete(&alg_data->mif.complete);
299 		}
300 	}
301 
302 	dev_dbg(&adap->dev, "%s(): exiting: stat = %04x.\n",
303 		__func__, ioread32(I2C_REG_STS(alg_data)));
304 
305 	return 0;
306 }
307 
308 static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id)
309 {
310 	u32 stat, ctl;
311 	struct i2c_adapter *adap = dev_id;
312 	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
313 
314 	dev_dbg(&adap->dev, "%s(): mstat = %x mctrl = %x, mode = %d\n",
315 		__func__,
316 		ioread32(I2C_REG_STS(alg_data)),
317 		ioread32(I2C_REG_CTL(alg_data)),
318 		alg_data->mif.mode);
319 	stat = ioread32(I2C_REG_STS(alg_data));
320 
321 	/* let's see what kind of event this is */
322 	if (stat & mstatus_afi) {
323 		/* We lost arbitration in the midst of a transfer */
324 		alg_data->mif.ret = -EIO;
325 
326 		/* Disable master interrupts. */
327 		ctl = ioread32(I2C_REG_CTL(alg_data));
328 		ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
329 			 mcntrl_drmie);
330 		iowrite32(ctl, I2C_REG_CTL(alg_data));
331 
332 		/* Stop timer, to prevent timeout. */
333 		del_timer_sync(&alg_data->mif.timer);
334 		complete(&alg_data->mif.complete);
335 	} else if (stat & mstatus_nai) {
336 		/* Slave did not acknowledge, generate a STOP */
337 		dev_dbg(&adap->dev, "%s(): "
338 			"Slave did not acknowledge, generating a STOP.\n",
339 			__func__);
340 		i2c_pnx_stop(adap);
341 
342 		/* Disable master interrupts. */
343 		ctl = ioread32(I2C_REG_CTL(alg_data));
344 		ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
345 			 mcntrl_drmie);
346 		iowrite32(ctl, I2C_REG_CTL(alg_data));
347 
348 		/* Our return value. */
349 		alg_data->mif.ret = -EIO;
350 
351 		/* Stop timer, to prevent timeout. */
352 		del_timer_sync(&alg_data->mif.timer);
353 		complete(&alg_data->mif.complete);
354 	} else {
355 		/*
356 		 * Two options:
357 		 * - Master Tx needs data.
358 		 * - There is data in the Rx-fifo
359 		 * The latter is only the case if we have requested for data,
360 		 * via a dummy write. (See 'i2c_pnx_master_rcv'.)
361 		 * We therefore check, as a sanity check, whether that interrupt
362 		 * has been enabled.
363 		 */
364 		if ((stat & mstatus_drmi) || !(stat & mstatus_rfe)) {
365 			if (alg_data->mif.mode == I2C_SMBUS_WRITE) {
366 				i2c_pnx_master_xmit(adap);
367 			} else if (alg_data->mif.mode == I2C_SMBUS_READ) {
368 				i2c_pnx_master_rcv(adap);
369 			}
370 		}
371 	}
372 
373 	/* Clear TDI and AFI bits */
374 	stat = ioread32(I2C_REG_STS(alg_data));
375 	iowrite32(stat | mstatus_tdi | mstatus_afi, I2C_REG_STS(alg_data));
376 
377 	dev_dbg(&adap->dev, "%s(): exiting, stat = %x ctrl = %x.\n",
378 		 __func__, ioread32(I2C_REG_STS(alg_data)),
379 		 ioread32(I2C_REG_CTL(alg_data)));
380 
381 	return IRQ_HANDLED;
382 }
383 
384 static void i2c_pnx_timeout(unsigned long data)
385 {
386 	struct i2c_adapter *adap = (struct i2c_adapter *)data;
387 	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
388 	u32 ctl;
389 
390 	dev_err(&adap->dev, "Master timed out. stat = %04x, cntrl = %04x. "
391 	       "Resetting master...\n",
392 	       ioread32(I2C_REG_STS(alg_data)),
393 	       ioread32(I2C_REG_CTL(alg_data)));
394 
395 	/* Reset master and disable interrupts */
396 	ctl = ioread32(I2C_REG_CTL(alg_data));
397 	ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie | mcntrl_drmie);
398 	iowrite32(ctl, I2C_REG_CTL(alg_data));
399 
400 	ctl |= mcntrl_reset;
401 	iowrite32(ctl, I2C_REG_CTL(alg_data));
402 	wait_reset(I2C_PNX_TIMEOUT, alg_data);
403 	alg_data->mif.ret = -EIO;
404 	complete(&alg_data->mif.complete);
405 }
406 
407 static inline void bus_reset_if_active(struct i2c_adapter *adap)
408 {
409 	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
410 	u32 stat;
411 
412 	if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_active) {
413 		dev_err(&adap->dev,
414 			"%s: Bus is still active after xfer. Reset it...\n",
415 		       adap->name);
416 		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
417 			  I2C_REG_CTL(alg_data));
418 		wait_reset(I2C_PNX_TIMEOUT, alg_data);
419 	} else if (!(stat & mstatus_rfe) || !(stat & mstatus_tfe)) {
420 		/* If there is data in the fifo's after transfer,
421 		 * flush fifo's by reset.
422 		 */
423 		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
424 			  I2C_REG_CTL(alg_data));
425 		wait_reset(I2C_PNX_TIMEOUT, alg_data);
426 	} else if (stat & mstatus_nai) {
427 		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
428 			  I2C_REG_CTL(alg_data));
429 		wait_reset(I2C_PNX_TIMEOUT, alg_data);
430 	}
431 }
432 
433 /**
434  * i2c_pnx_xfer - generic transfer entry point
435  * @adap:		pointer to I2C adapter structure
436  * @msgs:		array of messages
437  * @num:		number of messages
438  *
439  * Initiates the transfer
440  */
441 static int
442 i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
443 {
444 	struct i2c_msg *pmsg;
445 	int rc = 0, completed = 0, i;
446 	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
447 	u32 stat = ioread32(I2C_REG_STS(alg_data));
448 
449 	dev_dbg(&adap->dev, "%s(): entering: %d messages, stat = %04x.\n",
450 		__func__, num, ioread32(I2C_REG_STS(alg_data)));
451 
452 	bus_reset_if_active(adap);
453 
454 	/* Process transactions in a loop. */
455 	for (i = 0; rc >= 0 && i < num; i++) {
456 		u8 addr;
457 
458 		pmsg = &msgs[i];
459 		addr = pmsg->addr;
460 
461 		if (pmsg->flags & I2C_M_TEN) {
462 			dev_err(&adap->dev,
463 				"%s: 10 bits addr not supported!\n",
464 				adap->name);
465 			rc = -EINVAL;
466 			break;
467 		}
468 
469 		alg_data->mif.buf = pmsg->buf;
470 		alg_data->mif.len = pmsg->len;
471 		alg_data->mif.mode = (pmsg->flags & I2C_M_RD) ?
472 			I2C_SMBUS_READ : I2C_SMBUS_WRITE;
473 		alg_data->mif.ret = 0;
474 		alg_data->last = (i == num - 1);
475 
476 		dev_dbg(&adap->dev, "%s(): mode %d, %d bytes\n", __func__,
477 			alg_data->mif.mode,
478 			alg_data->mif.len);
479 
480 		i2c_pnx_arm_timer(adap);
481 
482 		/* initialize the completion var */
483 		init_completion(&alg_data->mif.complete);
484 
485 		/* Enable master interrupt */
486 		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_afie |
487 				mcntrl_naie | mcntrl_drmie,
488 			  I2C_REG_CTL(alg_data));
489 
490 		/* Put start-code and slave-address on the bus. */
491 		rc = i2c_pnx_start(addr, adap);
492 		if (rc < 0)
493 			break;
494 
495 		/* Wait for completion */
496 		wait_for_completion(&alg_data->mif.complete);
497 
498 		if (!(rc = alg_data->mif.ret))
499 			completed++;
500 		dev_dbg(&adap->dev, "%s(): Complete, return code = %d.\n",
501 			__func__, rc);
502 
503 		/* Clear TDI and AFI bits in case they are set. */
504 		if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_tdi) {
505 			dev_dbg(&adap->dev,
506 				"%s: TDI still set... clearing now.\n",
507 			       adap->name);
508 			iowrite32(stat, I2C_REG_STS(alg_data));
509 		}
510 		if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_afi) {
511 			dev_dbg(&adap->dev,
512 				"%s: AFI still set... clearing now.\n",
513 			       adap->name);
514 			iowrite32(stat, I2C_REG_STS(alg_data));
515 		}
516 	}
517 
518 	bus_reset_if_active(adap);
519 
520 	/* Cleanup to be sure... */
521 	alg_data->mif.buf = NULL;
522 	alg_data->mif.len = 0;
523 
524 	dev_dbg(&adap->dev, "%s(): exiting, stat = %x\n",
525 		__func__, ioread32(I2C_REG_STS(alg_data)));
526 
527 	if (completed != num)
528 		return ((rc < 0) ? rc : -EREMOTEIO);
529 
530 	return num;
531 }
532 
533 static u32 i2c_pnx_func(struct i2c_adapter *adapter)
534 {
535 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
536 }
537 
538 static struct i2c_algorithm pnx_algorithm = {
539 	.master_xfer = i2c_pnx_xfer,
540 	.functionality = i2c_pnx_func,
541 };
542 
543 static int i2c_pnx_controller_suspend(struct platform_device *pdev,
544 				      pm_message_t state)
545 {
546 	struct i2c_pnx_data *i2c_pnx = platform_get_drvdata(pdev);
547 	return i2c_pnx->suspend(pdev, state);
548 }
549 
550 static int i2c_pnx_controller_resume(struct platform_device *pdev)
551 {
552 	struct i2c_pnx_data *i2c_pnx = platform_get_drvdata(pdev);
553 	return i2c_pnx->resume(pdev);
554 }
555 
556 static int __devinit i2c_pnx_probe(struct platform_device *pdev)
557 {
558 	unsigned long tmp;
559 	int ret = 0;
560 	struct i2c_pnx_algo_data *alg_data;
561 	int freq_mhz;
562 	struct i2c_pnx_data *i2c_pnx = pdev->dev.platform_data;
563 
564 	if (!i2c_pnx || !i2c_pnx->adapter) {
565 		dev_err(&pdev->dev, "%s: no platform data supplied\n",
566 		       __func__);
567 		ret = -EINVAL;
568 		goto out;
569 	}
570 
571 	platform_set_drvdata(pdev, i2c_pnx);
572 
573 	if (i2c_pnx->calculate_input_freq)
574 		freq_mhz = i2c_pnx->calculate_input_freq(pdev);
575 	else {
576 		freq_mhz = PNX_DEFAULT_FREQ;
577 		dev_info(&pdev->dev, "Setting bus frequency to default value: "
578 		       "%d MHz\n", freq_mhz);
579 	}
580 
581 	i2c_pnx->adapter->algo = &pnx_algorithm;
582 
583 	alg_data = i2c_pnx->adapter->algo_data;
584 	init_timer(&alg_data->mif.timer);
585 	alg_data->mif.timer.function = i2c_pnx_timeout;
586 	alg_data->mif.timer.data = (unsigned long)i2c_pnx->adapter;
587 
588 	/* Register I/O resource */
589 	if (!request_region(alg_data->base, I2C_PNX_REGION_SIZE, pdev->name)) {
590 		dev_err(&pdev->dev,
591 		       "I/O region 0x%08x for I2C already in use.\n",
592 		       alg_data->base);
593 		ret = -ENODEV;
594 		goto out_drvdata;
595 	}
596 
597 	if (!(alg_data->ioaddr =
598 			(u32)ioremap(alg_data->base, I2C_PNX_REGION_SIZE))) {
599 		dev_err(&pdev->dev, "Couldn't ioremap I2C I/O region\n");
600 		ret = -ENOMEM;
601 		goto out_release;
602 	}
603 
604 	i2c_pnx->set_clock_run(pdev);
605 
606 	/*
607 	 * Clock Divisor High This value is the number of system clocks
608 	 * the serial clock (SCL) will be high.
609 	 * For example, if the system clock period is 50 ns and the maximum
610 	 * desired serial period is 10000 ns (100 kHz), then CLKHI would be
611 	 * set to 0.5*(f_sys/f_i2c)-2=0.5*(20e6/100e3)-2=98. The actual value
612 	 * programmed into CLKHI will vary from this slightly due to
613 	 * variations in the output pad's rise and fall times as well as
614 	 * the deglitching filter length.
615 	 */
616 
617 	tmp = ((freq_mhz * 1000) / I2C_PNX_SPEED_KHZ) / 2 - 2;
618 	iowrite32(tmp, I2C_REG_CKH(alg_data));
619 	iowrite32(tmp, I2C_REG_CKL(alg_data));
620 
621 	iowrite32(mcntrl_reset, I2C_REG_CTL(alg_data));
622 	if (wait_reset(I2C_PNX_TIMEOUT, alg_data)) {
623 		ret = -ENODEV;
624 		goto out_unmap;
625 	}
626 	init_completion(&alg_data->mif.complete);
627 
628 	ret = request_irq(alg_data->irq, i2c_pnx_interrupt,
629 			0, pdev->name, i2c_pnx->adapter);
630 	if (ret)
631 		goto out_clock;
632 
633 	/* Register this adapter with the I2C subsystem */
634 	i2c_pnx->adapter->dev.parent = &pdev->dev;
635 	ret = i2c_add_adapter(i2c_pnx->adapter);
636 	if (ret < 0) {
637 		dev_err(&pdev->dev, "I2C: Failed to add bus\n");
638 		goto out_irq;
639 	}
640 
641 	dev_dbg(&pdev->dev, "%s: Master at %#8x, irq %d.\n",
642 	       i2c_pnx->adapter->name, alg_data->base, alg_data->irq);
643 
644 	return 0;
645 
646 out_irq:
647 	free_irq(alg_data->irq, alg_data);
648 out_clock:
649 	i2c_pnx->set_clock_stop(pdev);
650 out_unmap:
651 	iounmap((void *)alg_data->ioaddr);
652 out_release:
653 	release_region(alg_data->base, I2C_PNX_REGION_SIZE);
654 out_drvdata:
655 	platform_set_drvdata(pdev, NULL);
656 out:
657 	return ret;
658 }
659 
660 static int __devexit i2c_pnx_remove(struct platform_device *pdev)
661 {
662 	struct i2c_pnx_data *i2c_pnx = platform_get_drvdata(pdev);
663 	struct i2c_adapter *adap = i2c_pnx->adapter;
664 	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
665 
666 	free_irq(alg_data->irq, alg_data);
667 	i2c_del_adapter(adap);
668 	i2c_pnx->set_clock_stop(pdev);
669 	iounmap((void *)alg_data->ioaddr);
670 	release_region(alg_data->base, I2C_PNX_REGION_SIZE);
671 	platform_set_drvdata(pdev, NULL);
672 
673 	return 0;
674 }
675 
676 static struct platform_driver i2c_pnx_driver = {
677 	.driver = {
678 		.name = "pnx-i2c",
679 		.owner = THIS_MODULE,
680 	},
681 	.probe = i2c_pnx_probe,
682 	.remove = __devexit_p(i2c_pnx_remove),
683 	.suspend = i2c_pnx_controller_suspend,
684 	.resume = i2c_pnx_controller_resume,
685 };
686 
687 static int __init i2c_adap_pnx_init(void)
688 {
689 	return platform_driver_register(&i2c_pnx_driver);
690 }
691 
692 static void __exit i2c_adap_pnx_exit(void)
693 {
694 	platform_driver_unregister(&i2c_pnx_driver);
695 }
696 
697 MODULE_AUTHOR("Vitaly Wool, Dennis Kovalev <source@mvista.com>");
698 MODULE_DESCRIPTION("I2C driver for Philips IP3204-based I2C busses");
699 MODULE_LICENSE("GPL");
700 MODULE_ALIAS("platform:pnx-i2c");
701 
702 /* We need to make sure I2C is initialized before USB */
703 subsys_initcall(i2c_adap_pnx_init);
704 module_exit(i2c_adap_pnx_exit);
705