xref: /openbmc/linux/drivers/i2c/busses/i2c-pnx.c (revision 5bd8e16d)
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 <linux/io.h>
23 #include <linux/err.h>
24 #include <linux/clk.h>
25 #include <linux/slab.h>
26 
27 #define I2C_PNX_TIMEOUT_DEFAULT		10 /* msec */
28 #define I2C_PNX_SPEED_KHZ_DEFAULT	100
29 #define I2C_PNX_REGION_SIZE		0x100
30 
31 enum {
32 	mstatus_tdi = 0x00000001,
33 	mstatus_afi = 0x00000002,
34 	mstatus_nai = 0x00000004,
35 	mstatus_drmi = 0x00000008,
36 	mstatus_active = 0x00000020,
37 	mstatus_scl = 0x00000040,
38 	mstatus_sda = 0x00000080,
39 	mstatus_rff = 0x00000100,
40 	mstatus_rfe = 0x00000200,
41 	mstatus_tff = 0x00000400,
42 	mstatus_tfe = 0x00000800,
43 };
44 
45 enum {
46 	mcntrl_tdie = 0x00000001,
47 	mcntrl_afie = 0x00000002,
48 	mcntrl_naie = 0x00000004,
49 	mcntrl_drmie = 0x00000008,
50 	mcntrl_drsie = 0x00000010,
51 	mcntrl_rffie = 0x00000020,
52 	mcntrl_daie = 0x00000040,
53 	mcntrl_tffie = 0x00000080,
54 	mcntrl_reset = 0x00000100,
55 	mcntrl_cdbmode = 0x00000400,
56 };
57 
58 enum {
59 	rw_bit = 1 << 0,
60 	start_bit = 1 << 8,
61 	stop_bit = 1 << 9,
62 };
63 
64 #define I2C_REG_RX(a)	((a)->ioaddr)		/* Rx FIFO reg (RO) */
65 #define I2C_REG_TX(a)	((a)->ioaddr)		/* Tx FIFO reg (WO) */
66 #define I2C_REG_STS(a)	((a)->ioaddr + 0x04)	/* Status reg (RO) */
67 #define I2C_REG_CTL(a)	((a)->ioaddr + 0x08)	/* Ctl reg */
68 #define I2C_REG_CKL(a)	((a)->ioaddr + 0x0c)	/* Clock divider low */
69 #define I2C_REG_CKH(a)	((a)->ioaddr + 0x10)	/* Clock divider high */
70 #define I2C_REG_ADR(a)	((a)->ioaddr + 0x14)	/* I2C address */
71 #define I2C_REG_RFL(a)	((a)->ioaddr + 0x18)	/* Rx FIFO level (RO) */
72 #define I2C_REG_TFL(a)	((a)->ioaddr + 0x1c)	/* Tx FIFO level (RO) */
73 #define I2C_REG_RXB(a)	((a)->ioaddr + 0x20)	/* Num of bytes Rx-ed (RO) */
74 #define I2C_REG_TXB(a)	((a)->ioaddr + 0x24)	/* Num of bytes Tx-ed (RO) */
75 #define I2C_REG_TXS(a)	((a)->ioaddr + 0x28)	/* Tx slave FIFO (RO) */
76 #define I2C_REG_STFL(a)	((a)->ioaddr + 0x2c)	/* Tx slave FIFO level (RO) */
77 
78 static inline int wait_timeout(struct i2c_pnx_algo_data *data)
79 {
80 	long timeout = data->timeout;
81 	while (timeout > 0 &&
82 			(ioread32(I2C_REG_STS(data)) & mstatus_active)) {
83 		mdelay(1);
84 		timeout--;
85 	}
86 	return (timeout <= 0);
87 }
88 
89 static inline int wait_reset(struct i2c_pnx_algo_data *data)
90 {
91 	long timeout = data->timeout;
92 	while (timeout > 0 &&
93 			(ioread32(I2C_REG_CTL(data)) & mcntrl_reset)) {
94 		mdelay(1);
95 		timeout--;
96 	}
97 	return (timeout <= 0);
98 }
99 
100 static inline void i2c_pnx_arm_timer(struct i2c_pnx_algo_data *alg_data)
101 {
102 	struct timer_list *timer = &alg_data->mif.timer;
103 	unsigned long expires = msecs_to_jiffies(alg_data->timeout);
104 
105 	if (expires <= 1)
106 		expires = 2;
107 
108 	del_timer_sync(timer);
109 
110 	dev_dbg(&alg_data->adapter.dev, "Timer armed at %lu plus %lu jiffies.\n",
111 		jiffies, expires);
112 
113 	timer->expires = jiffies + expires;
114 	timer->data = (unsigned long)alg_data;
115 
116 	add_timer(timer);
117 }
118 
119 /**
120  * i2c_pnx_start - start a device
121  * @slave_addr:		slave address
122  * @adap:		pointer to adapter structure
123  *
124  * Generate a START signal in the desired mode.
125  */
126 static int i2c_pnx_start(unsigned char slave_addr,
127 	struct i2c_pnx_algo_data *alg_data)
128 {
129 	dev_dbg(&alg_data->adapter.dev, "%s(): addr 0x%x mode %d\n", __func__,
130 		slave_addr, alg_data->mif.mode);
131 
132 	/* Check for 7 bit slave addresses only */
133 	if (slave_addr & ~0x7f) {
134 		dev_err(&alg_data->adapter.dev,
135 			"%s: Invalid slave address %x. Only 7-bit addresses are supported\n",
136 			alg_data->adapter.name, slave_addr);
137 		return -EINVAL;
138 	}
139 
140 	/* First, make sure bus is idle */
141 	if (wait_timeout(alg_data)) {
142 		/* Somebody else is monopolizing the bus */
143 		dev_err(&alg_data->adapter.dev,
144 			"%s: Bus busy. Slave addr = %02x, cntrl = %x, stat = %x\n",
145 			alg_data->adapter.name, slave_addr,
146 			ioread32(I2C_REG_CTL(alg_data)),
147 			ioread32(I2C_REG_STS(alg_data)));
148 		return -EBUSY;
149 	} else if (ioread32(I2C_REG_STS(alg_data)) & mstatus_afi) {
150 		/* Sorry, we lost the bus */
151 		dev_err(&alg_data->adapter.dev,
152 		        "%s: Arbitration failure. Slave addr = %02x\n",
153 			alg_data->adapter.name, slave_addr);
154 		return -EIO;
155 	}
156 
157 	/*
158 	 * OK, I2C is enabled and we have the bus.
159 	 * Clear the current TDI and AFI status flags.
160 	 */
161 	iowrite32(ioread32(I2C_REG_STS(alg_data)) | mstatus_tdi | mstatus_afi,
162 		  I2C_REG_STS(alg_data));
163 
164 	dev_dbg(&alg_data->adapter.dev, "%s(): sending %#x\n", __func__,
165 		(slave_addr << 1) | start_bit | alg_data->mif.mode);
166 
167 	/* Write the slave address, START bit and R/W bit */
168 	iowrite32((slave_addr << 1) | start_bit | alg_data->mif.mode,
169 		  I2C_REG_TX(alg_data));
170 
171 	dev_dbg(&alg_data->adapter.dev, "%s(): exit\n", __func__);
172 
173 	return 0;
174 }
175 
176 /**
177  * i2c_pnx_stop - stop a device
178  * @adap:		pointer to I2C adapter structure
179  *
180  * Generate a STOP signal to terminate the master transaction.
181  */
182 static void i2c_pnx_stop(struct i2c_pnx_algo_data *alg_data)
183 {
184 	/* Only 1 msec max timeout due to interrupt context */
185 	long timeout = 1000;
186 
187 	dev_dbg(&alg_data->adapter.dev, "%s(): entering: stat = %04x.\n",
188 		__func__, ioread32(I2C_REG_STS(alg_data)));
189 
190 	/* Write a STOP bit to TX FIFO */
191 	iowrite32(0xff | stop_bit, I2C_REG_TX(alg_data));
192 
193 	/* Wait until the STOP is seen. */
194 	while (timeout > 0 &&
195 	       (ioread32(I2C_REG_STS(alg_data)) & mstatus_active)) {
196 		/* may be called from interrupt context */
197 		udelay(1);
198 		timeout--;
199 	}
200 
201 	dev_dbg(&alg_data->adapter.dev, "%s(): exiting: stat = %04x.\n",
202 		__func__, ioread32(I2C_REG_STS(alg_data)));
203 }
204 
205 /**
206  * i2c_pnx_master_xmit - transmit data to slave
207  * @adap:		pointer to I2C adapter structure
208  *
209  * Sends one byte of data to the slave
210  */
211 static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data)
212 {
213 	u32 val;
214 
215 	dev_dbg(&alg_data->adapter.dev, "%s(): entering: stat = %04x.\n",
216 		__func__, ioread32(I2C_REG_STS(alg_data)));
217 
218 	if (alg_data->mif.len > 0) {
219 		/* We still have something to talk about... */
220 		val = *alg_data->mif.buf++;
221 
222 		if (alg_data->mif.len == 1)
223 			val |= stop_bit;
224 
225 		alg_data->mif.len--;
226 		iowrite32(val, I2C_REG_TX(alg_data));
227 
228 		dev_dbg(&alg_data->adapter.dev, "%s(): xmit %#x [%d]\n",
229 			__func__, val, alg_data->mif.len + 1);
230 
231 		if (alg_data->mif.len == 0) {
232 			if (alg_data->last) {
233 				/* Wait until the STOP is seen. */
234 				if (wait_timeout(alg_data))
235 					dev_err(&alg_data->adapter.dev,
236 						"The bus is still active after timeout\n");
237 			}
238 			/* Disable master interrupts */
239 			iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
240 				~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
241 				  I2C_REG_CTL(alg_data));
242 
243 			del_timer_sync(&alg_data->mif.timer);
244 
245 			dev_dbg(&alg_data->adapter.dev,
246 				"%s(): Waking up xfer routine.\n",
247 				__func__);
248 
249 			complete(&alg_data->mif.complete);
250 		}
251 	} else if (alg_data->mif.len == 0) {
252 		/* zero-sized transfer */
253 		i2c_pnx_stop(alg_data);
254 
255 		/* Disable master interrupts. */
256 		iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
257 			~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
258 			  I2C_REG_CTL(alg_data));
259 
260 		/* Stop timer. */
261 		del_timer_sync(&alg_data->mif.timer);
262 		dev_dbg(&alg_data->adapter.dev,
263 			"%s(): Waking up xfer routine after zero-xfer.\n",
264 			__func__);
265 
266 		complete(&alg_data->mif.complete);
267 	}
268 
269 	dev_dbg(&alg_data->adapter.dev, "%s(): exiting: stat = %04x.\n",
270 		__func__, ioread32(I2C_REG_STS(alg_data)));
271 
272 	return 0;
273 }
274 
275 /**
276  * i2c_pnx_master_rcv - receive data from slave
277  * @adap:		pointer to I2C adapter structure
278  *
279  * Reads one byte data from the slave
280  */
281 static int i2c_pnx_master_rcv(struct i2c_pnx_algo_data *alg_data)
282 {
283 	unsigned int val = 0;
284 	u32 ctl = 0;
285 
286 	dev_dbg(&alg_data->adapter.dev, "%s(): entering: stat = %04x.\n",
287 		__func__, ioread32(I2C_REG_STS(alg_data)));
288 
289 	/* Check, whether there is already data,
290 	 * or we didn't 'ask' for it yet.
291 	 */
292 	if (ioread32(I2C_REG_STS(alg_data)) & mstatus_rfe) {
293 		/* 'Asking' is done asynchronously, e.g. dummy TX of several
294 		 * bytes is done before the first actual RX arrives in FIFO.
295 		 * Therefore, ordered bytes (via TX) are counted separately.
296 		 */
297 		if (alg_data->mif.order) {
298 			dev_dbg(&alg_data->adapter.dev,
299 				"%s(): Write dummy data to fill Rx-fifo...\n",
300 				__func__);
301 
302 			if (alg_data->mif.order == 1) {
303 				/* Last byte, do not acknowledge next rcv. */
304 				val |= stop_bit;
305 
306 				/*
307 				 * Enable interrupt RFDAIE (data in Rx fifo),
308 				 * and disable DRMIE (need data for Tx)
309 				 */
310 				ctl = ioread32(I2C_REG_CTL(alg_data));
311 				ctl |= mcntrl_rffie | mcntrl_daie;
312 				ctl &= ~mcntrl_drmie;
313 				iowrite32(ctl, I2C_REG_CTL(alg_data));
314 			}
315 
316 			/*
317 			 * Now we'll 'ask' for data:
318 			 * For each byte we want to receive, we must
319 			 * write a (dummy) byte to the Tx-FIFO.
320 			 */
321 			iowrite32(val, I2C_REG_TX(alg_data));
322 			alg_data->mif.order--;
323 		}
324 		return 0;
325 	}
326 
327 	/* Handle data. */
328 	if (alg_data->mif.len > 0) {
329 		val = ioread32(I2C_REG_RX(alg_data));
330 		*alg_data->mif.buf++ = (u8) (val & 0xff);
331 		dev_dbg(&alg_data->adapter.dev, "%s(): rcv 0x%x [%d]\n",
332 			__func__, val, alg_data->mif.len);
333 
334 		alg_data->mif.len--;
335 		if (alg_data->mif.len == 0) {
336 			if (alg_data->last)
337 				/* Wait until the STOP is seen. */
338 				if (wait_timeout(alg_data))
339 					dev_err(&alg_data->adapter.dev,
340 						"The bus is still active after timeout\n");
341 
342 			/* Disable master interrupts */
343 			ctl = ioread32(I2C_REG_CTL(alg_data));
344 			ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
345 				 mcntrl_drmie | mcntrl_daie);
346 			iowrite32(ctl, I2C_REG_CTL(alg_data));
347 
348 			/* Kill timer. */
349 			del_timer_sync(&alg_data->mif.timer);
350 			complete(&alg_data->mif.complete);
351 		}
352 	}
353 
354 	dev_dbg(&alg_data->adapter.dev, "%s(): exiting: stat = %04x.\n",
355 		__func__, ioread32(I2C_REG_STS(alg_data)));
356 
357 	return 0;
358 }
359 
360 static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id)
361 {
362 	struct i2c_pnx_algo_data *alg_data = dev_id;
363 	u32 stat, ctl;
364 
365 	dev_dbg(&alg_data->adapter.dev,
366 		"%s(): mstat = %x mctrl = %x, mode = %d\n",
367 		__func__,
368 		ioread32(I2C_REG_STS(alg_data)),
369 		ioread32(I2C_REG_CTL(alg_data)),
370 		alg_data->mif.mode);
371 	stat = ioread32(I2C_REG_STS(alg_data));
372 
373 	/* let's see what kind of event this is */
374 	if (stat & mstatus_afi) {
375 		/* We lost arbitration in the midst of a transfer */
376 		alg_data->mif.ret = -EIO;
377 
378 		/* Disable master interrupts. */
379 		ctl = ioread32(I2C_REG_CTL(alg_data));
380 		ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
381 			 mcntrl_drmie);
382 		iowrite32(ctl, I2C_REG_CTL(alg_data));
383 
384 		/* Stop timer, to prevent timeout. */
385 		del_timer_sync(&alg_data->mif.timer);
386 		complete(&alg_data->mif.complete);
387 	} else if (stat & mstatus_nai) {
388 		/* Slave did not acknowledge, generate a STOP */
389 		dev_dbg(&alg_data->adapter.dev,
390 			"%s(): Slave did not acknowledge, generating a STOP.\n",
391 			__func__);
392 		i2c_pnx_stop(alg_data);
393 
394 		/* Disable master interrupts. */
395 		ctl = ioread32(I2C_REG_CTL(alg_data));
396 		ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
397 			 mcntrl_drmie);
398 		iowrite32(ctl, I2C_REG_CTL(alg_data));
399 
400 		/* Our return value. */
401 		alg_data->mif.ret = -EIO;
402 
403 		/* Stop timer, to prevent timeout. */
404 		del_timer_sync(&alg_data->mif.timer);
405 		complete(&alg_data->mif.complete);
406 	} else {
407 		/*
408 		 * Two options:
409 		 * - Master Tx needs data.
410 		 * - There is data in the Rx-fifo
411 		 * The latter is only the case if we have requested for data,
412 		 * via a dummy write. (See 'i2c_pnx_master_rcv'.)
413 		 * We therefore check, as a sanity check, whether that interrupt
414 		 * has been enabled.
415 		 */
416 		if ((stat & mstatus_drmi) || !(stat & mstatus_rfe)) {
417 			if (alg_data->mif.mode == I2C_SMBUS_WRITE) {
418 				i2c_pnx_master_xmit(alg_data);
419 			} else if (alg_data->mif.mode == I2C_SMBUS_READ) {
420 				i2c_pnx_master_rcv(alg_data);
421 			}
422 		}
423 	}
424 
425 	/* Clear TDI and AFI bits */
426 	stat = ioread32(I2C_REG_STS(alg_data));
427 	iowrite32(stat | mstatus_tdi | mstatus_afi, I2C_REG_STS(alg_data));
428 
429 	dev_dbg(&alg_data->adapter.dev,
430 		"%s(): exiting, stat = %x ctrl = %x.\n",
431 		 __func__, ioread32(I2C_REG_STS(alg_data)),
432 		 ioread32(I2C_REG_CTL(alg_data)));
433 
434 	return IRQ_HANDLED;
435 }
436 
437 static void i2c_pnx_timeout(unsigned long data)
438 {
439 	struct i2c_pnx_algo_data *alg_data = (struct i2c_pnx_algo_data *)data;
440 	u32 ctl;
441 
442 	dev_err(&alg_data->adapter.dev,
443 		"Master timed out. stat = %04x, cntrl = %04x. Resetting master...\n",
444 		ioread32(I2C_REG_STS(alg_data)),
445 		ioread32(I2C_REG_CTL(alg_data)));
446 
447 	/* Reset master and disable interrupts */
448 	ctl = ioread32(I2C_REG_CTL(alg_data));
449 	ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie | mcntrl_drmie);
450 	iowrite32(ctl, I2C_REG_CTL(alg_data));
451 
452 	ctl |= mcntrl_reset;
453 	iowrite32(ctl, I2C_REG_CTL(alg_data));
454 	wait_reset(alg_data);
455 	alg_data->mif.ret = -EIO;
456 	complete(&alg_data->mif.complete);
457 }
458 
459 static inline void bus_reset_if_active(struct i2c_pnx_algo_data *alg_data)
460 {
461 	u32 stat;
462 
463 	if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_active) {
464 		dev_err(&alg_data->adapter.dev,
465 			"%s: Bus is still active after xfer. Reset it...\n",
466 			alg_data->adapter.name);
467 		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
468 			  I2C_REG_CTL(alg_data));
469 		wait_reset(alg_data);
470 	} else if (!(stat & mstatus_rfe) || !(stat & mstatus_tfe)) {
471 		/* If there is data in the fifo's after transfer,
472 		 * flush fifo's by reset.
473 		 */
474 		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
475 			  I2C_REG_CTL(alg_data));
476 		wait_reset(alg_data);
477 	} else if (stat & mstatus_nai) {
478 		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
479 			  I2C_REG_CTL(alg_data));
480 		wait_reset(alg_data);
481 	}
482 }
483 
484 /**
485  * i2c_pnx_xfer - generic transfer entry point
486  * @adap:		pointer to I2C adapter structure
487  * @msgs:		array of messages
488  * @num:		number of messages
489  *
490  * Initiates the transfer
491  */
492 static int
493 i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
494 {
495 	struct i2c_msg *pmsg;
496 	int rc = 0, completed = 0, i;
497 	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
498 	u32 stat = ioread32(I2C_REG_STS(alg_data));
499 
500 	dev_dbg(&alg_data->adapter.dev,
501 		"%s(): entering: %d messages, stat = %04x.\n",
502 		__func__, num, ioread32(I2C_REG_STS(alg_data)));
503 
504 	bus_reset_if_active(alg_data);
505 
506 	/* Process transactions in a loop. */
507 	for (i = 0; rc >= 0 && i < num; i++) {
508 		u8 addr;
509 
510 		pmsg = &msgs[i];
511 		addr = pmsg->addr;
512 
513 		if (pmsg->flags & I2C_M_TEN) {
514 			dev_err(&alg_data->adapter.dev,
515 				"%s: 10 bits addr not supported!\n",
516 				alg_data->adapter.name);
517 			rc = -EINVAL;
518 			break;
519 		}
520 
521 		alg_data->mif.buf = pmsg->buf;
522 		alg_data->mif.len = pmsg->len;
523 		alg_data->mif.order = pmsg->len;
524 		alg_data->mif.mode = (pmsg->flags & I2C_M_RD) ?
525 			I2C_SMBUS_READ : I2C_SMBUS_WRITE;
526 		alg_data->mif.ret = 0;
527 		alg_data->last = (i == num - 1);
528 
529 		dev_dbg(&alg_data->adapter.dev, "%s(): mode %d, %d bytes\n",
530 			__func__, alg_data->mif.mode, alg_data->mif.len);
531 
532 		i2c_pnx_arm_timer(alg_data);
533 
534 		/* initialize the completion var */
535 		init_completion(&alg_data->mif.complete);
536 
537 		/* Enable master interrupt */
538 		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_afie |
539 				mcntrl_naie | mcntrl_drmie,
540 			  I2C_REG_CTL(alg_data));
541 
542 		/* Put start-code and slave-address on the bus. */
543 		rc = i2c_pnx_start(addr, alg_data);
544 		if (rc < 0)
545 			break;
546 
547 		/* Wait for completion */
548 		wait_for_completion(&alg_data->mif.complete);
549 
550 		if (!(rc = alg_data->mif.ret))
551 			completed++;
552 		dev_dbg(&alg_data->adapter.dev,
553 			"%s(): Complete, return code = %d.\n",
554 			__func__, rc);
555 
556 		/* Clear TDI and AFI bits in case they are set. */
557 		if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_tdi) {
558 			dev_dbg(&alg_data->adapter.dev,
559 				"%s: TDI still set... clearing now.\n",
560 				alg_data->adapter.name);
561 			iowrite32(stat, I2C_REG_STS(alg_data));
562 		}
563 		if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_afi) {
564 			dev_dbg(&alg_data->adapter.dev,
565 				"%s: AFI still set... clearing now.\n",
566 				alg_data->adapter.name);
567 			iowrite32(stat, I2C_REG_STS(alg_data));
568 		}
569 	}
570 
571 	bus_reset_if_active(alg_data);
572 
573 	/* Cleanup to be sure... */
574 	alg_data->mif.buf = NULL;
575 	alg_data->mif.len = 0;
576 	alg_data->mif.order = 0;
577 
578 	dev_dbg(&alg_data->adapter.dev, "%s(): exiting, stat = %x\n",
579 		__func__, ioread32(I2C_REG_STS(alg_data)));
580 
581 	if (completed != num)
582 		return ((rc < 0) ? rc : -EREMOTEIO);
583 
584 	return num;
585 }
586 
587 static u32 i2c_pnx_func(struct i2c_adapter *adapter)
588 {
589 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
590 }
591 
592 static struct i2c_algorithm pnx_algorithm = {
593 	.master_xfer = i2c_pnx_xfer,
594 	.functionality = i2c_pnx_func,
595 };
596 
597 #ifdef CONFIG_PM_SLEEP
598 static int i2c_pnx_controller_suspend(struct device *dev)
599 {
600 	struct i2c_pnx_algo_data *alg_data = dev_get_drvdata(dev);
601 
602 	clk_disable(alg_data->clk);
603 
604 	return 0;
605 }
606 
607 static int i2c_pnx_controller_resume(struct device *dev)
608 {
609 	struct i2c_pnx_algo_data *alg_data = dev_get_drvdata(dev);
610 
611 	return clk_enable(alg_data->clk);
612 }
613 
614 static SIMPLE_DEV_PM_OPS(i2c_pnx_pm,
615 			 i2c_pnx_controller_suspend, i2c_pnx_controller_resume);
616 #define PNX_I2C_PM	(&i2c_pnx_pm)
617 #else
618 #define PNX_I2C_PM	NULL
619 #endif
620 
621 static int i2c_pnx_probe(struct platform_device *pdev)
622 {
623 	unsigned long tmp;
624 	int ret = 0;
625 	struct i2c_pnx_algo_data *alg_data;
626 	unsigned long freq;
627 	struct resource *res;
628 	u32 speed = I2C_PNX_SPEED_KHZ_DEFAULT * 1000;
629 
630 	alg_data = kzalloc(sizeof(*alg_data), GFP_KERNEL);
631 	if (!alg_data) {
632 		ret = -ENOMEM;
633 		goto err_kzalloc;
634 	}
635 
636 	platform_set_drvdata(pdev, alg_data);
637 
638 	alg_data->adapter.dev.parent = &pdev->dev;
639 	alg_data->adapter.algo = &pnx_algorithm;
640 	alg_data->adapter.algo_data = alg_data;
641 	alg_data->adapter.nr = pdev->id;
642 
643 	alg_data->timeout = I2C_PNX_TIMEOUT_DEFAULT;
644 #ifdef CONFIG_OF
645 	alg_data->adapter.dev.of_node = of_node_get(pdev->dev.of_node);
646 	if (pdev->dev.of_node) {
647 		of_property_read_u32(pdev->dev.of_node, "clock-frequency",
648 				     &speed);
649 		/*
650 		 * At this point, it is planned to add an OF timeout property.
651 		 * As soon as there is a consensus about how to call and handle
652 		 * this, sth. like the following can be put here:
653 		 *
654 		 * of_property_read_u32(pdev->dev.of_node, "timeout",
655 		 *                      &alg_data->timeout);
656 		 */
657 	}
658 #endif
659 	alg_data->clk = clk_get(&pdev->dev, NULL);
660 	if (IS_ERR(alg_data->clk)) {
661 		ret = PTR_ERR(alg_data->clk);
662 		goto out_drvdata;
663 	}
664 
665 	init_timer(&alg_data->mif.timer);
666 	alg_data->mif.timer.function = i2c_pnx_timeout;
667 	alg_data->mif.timer.data = (unsigned long)alg_data;
668 
669 	snprintf(alg_data->adapter.name, sizeof(alg_data->adapter.name),
670 		 "%s", pdev->name);
671 
672 	/* Register I/O resource */
673 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
674 	if (!res) {
675 		dev_err(&pdev->dev, "Unable to get mem resource.\n");
676 		ret = -EBUSY;
677 		goto out_clkget;
678 	}
679 	if (!request_mem_region(res->start, I2C_PNX_REGION_SIZE,
680 				pdev->name)) {
681 		dev_err(&pdev->dev,
682 		       "I/O region 0x%08x for I2C already in use.\n",
683 		       res->start);
684 		ret = -ENOMEM;
685 		goto out_clkget;
686 	}
687 
688 	alg_data->base = res->start;
689 	alg_data->ioaddr = ioremap(res->start, I2C_PNX_REGION_SIZE);
690 	if (!alg_data->ioaddr) {
691 		dev_err(&pdev->dev, "Couldn't ioremap I2C I/O region\n");
692 		ret = -ENOMEM;
693 		goto out_release;
694 	}
695 
696 	ret = clk_enable(alg_data->clk);
697 	if (ret)
698 		goto out_unmap;
699 
700 	freq = clk_get_rate(alg_data->clk);
701 
702 	/*
703 	 * Clock Divisor High This value is the number of system clocks
704 	 * the serial clock (SCL) will be high.
705 	 * For example, if the system clock period is 50 ns and the maximum
706 	 * desired serial period is 10000 ns (100 kHz), then CLKHI would be
707 	 * set to 0.5*(f_sys/f_i2c)-2=0.5*(20e6/100e3)-2=98. The actual value
708 	 * programmed into CLKHI will vary from this slightly due to
709 	 * variations in the output pad's rise and fall times as well as
710 	 * the deglitching filter length.
711 	 */
712 
713 	tmp = (freq / speed) / 2 - 2;
714 	if (tmp > 0x3FF)
715 		tmp = 0x3FF;
716 	iowrite32(tmp, I2C_REG_CKH(alg_data));
717 	iowrite32(tmp, I2C_REG_CKL(alg_data));
718 
719 	iowrite32(mcntrl_reset, I2C_REG_CTL(alg_data));
720 	if (wait_reset(alg_data)) {
721 		ret = -ENODEV;
722 		goto out_clock;
723 	}
724 	init_completion(&alg_data->mif.complete);
725 
726 	alg_data->irq = platform_get_irq(pdev, 0);
727 	if (alg_data->irq < 0) {
728 		dev_err(&pdev->dev, "Failed to get IRQ from platform resource\n");
729 		ret = alg_data->irq;
730 		goto out_clock;
731 	}
732 	ret = request_irq(alg_data->irq, i2c_pnx_interrupt,
733 			0, pdev->name, alg_data);
734 	if (ret)
735 		goto out_clock;
736 
737 	/* Register this adapter with the I2C subsystem */
738 	ret = i2c_add_numbered_adapter(&alg_data->adapter);
739 	if (ret < 0) {
740 		dev_err(&pdev->dev, "I2C: Failed to add bus\n");
741 		goto out_irq;
742 	}
743 
744 	dev_dbg(&pdev->dev, "%s: Master at %#8x, irq %d.\n",
745 		alg_data->adapter.name, res->start, alg_data->irq);
746 
747 	return 0;
748 
749 out_irq:
750 	free_irq(alg_data->irq, alg_data);
751 out_clock:
752 	clk_disable(alg_data->clk);
753 out_unmap:
754 	iounmap(alg_data->ioaddr);
755 out_release:
756 	release_mem_region(res->start, I2C_PNX_REGION_SIZE);
757 out_clkget:
758 	clk_put(alg_data->clk);
759 out_drvdata:
760 	kfree(alg_data);
761 err_kzalloc:
762 	return ret;
763 }
764 
765 static int i2c_pnx_remove(struct platform_device *pdev)
766 {
767 	struct i2c_pnx_algo_data *alg_data = platform_get_drvdata(pdev);
768 
769 	free_irq(alg_data->irq, alg_data);
770 	i2c_del_adapter(&alg_data->adapter);
771 	clk_disable(alg_data->clk);
772 	iounmap(alg_data->ioaddr);
773 	release_mem_region(alg_data->base, I2C_PNX_REGION_SIZE);
774 	clk_put(alg_data->clk);
775 	kfree(alg_data);
776 
777 	return 0;
778 }
779 
780 #ifdef CONFIG_OF
781 static const struct of_device_id i2c_pnx_of_match[] = {
782 	{ .compatible = "nxp,pnx-i2c" },
783 	{ },
784 };
785 MODULE_DEVICE_TABLE(of, i2c_pnx_of_match);
786 #endif
787 
788 static struct platform_driver i2c_pnx_driver = {
789 	.driver = {
790 		.name = "pnx-i2c",
791 		.owner = THIS_MODULE,
792 		.of_match_table = of_match_ptr(i2c_pnx_of_match),
793 		.pm = PNX_I2C_PM,
794 	},
795 	.probe = i2c_pnx_probe,
796 	.remove = i2c_pnx_remove,
797 };
798 
799 static int __init i2c_adap_pnx_init(void)
800 {
801 	return platform_driver_register(&i2c_pnx_driver);
802 }
803 
804 static void __exit i2c_adap_pnx_exit(void)
805 {
806 	platform_driver_unregister(&i2c_pnx_driver);
807 }
808 
809 MODULE_AUTHOR("Vitaly Wool, Dennis Kovalev <source@mvista.com>");
810 MODULE_DESCRIPTION("I2C driver for Philips IP3204-based I2C busses");
811 MODULE_LICENSE("GPL");
812 MODULE_ALIAS("platform:pnx-i2c");
813 
814 /* We need to make sure I2C is initialized before USB */
815 subsys_initcall(i2c_adap_pnx_init);
816 module_exit(i2c_adap_pnx_exit);
817