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/io.h>
22#include <linux/err.h>
23#include <linux/clk.h>
24#include <linux/slab.h>
25#include <linux/of.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
31struct i2c_pnx_mif {
32	int			ret;		/* Return value */
33	int			mode;		/* Interface mode */
34	struct completion	complete;	/* I/O completion */
35	struct timer_list	timer;		/* Timeout */
36	u8 *			buf;		/* Data buffer */
37	int			len;		/* Length of data buffer */
38	int			order;		/* RX Bytes to order via TX */
39};
40
41struct i2c_pnx_algo_data {
42	void __iomem		*ioaddr;
43	struct i2c_pnx_mif	mif;
44	int			last;
45	struct clk		*clk;
46	struct i2c_adapter	adapter;
47	int			irq;
48	u32			timeout;
49};
50
51enum {
52	mstatus_tdi = 0x00000001,
53	mstatus_afi = 0x00000002,
54	mstatus_nai = 0x00000004,
55	mstatus_drmi = 0x00000008,
56	mstatus_active = 0x00000020,
57	mstatus_scl = 0x00000040,
58	mstatus_sda = 0x00000080,
59	mstatus_rff = 0x00000100,
60	mstatus_rfe = 0x00000200,
61	mstatus_tff = 0x00000400,
62	mstatus_tfe = 0x00000800,
63};
64
65enum {
66	mcntrl_tdie = 0x00000001,
67	mcntrl_afie = 0x00000002,
68	mcntrl_naie = 0x00000004,
69	mcntrl_drmie = 0x00000008,
70	mcntrl_drsie = 0x00000010,
71	mcntrl_rffie = 0x00000020,
72	mcntrl_daie = 0x00000040,
73	mcntrl_tffie = 0x00000080,
74	mcntrl_reset = 0x00000100,
75	mcntrl_cdbmode = 0x00000400,
76};
77
78enum {
79	rw_bit = 1 << 0,
80	start_bit = 1 << 8,
81	stop_bit = 1 << 9,
82};
83
84#define I2C_REG_RX(a)	((a)->ioaddr)		/* Rx FIFO reg (RO) */
85#define I2C_REG_TX(a)	((a)->ioaddr)		/* Tx FIFO reg (WO) */
86#define I2C_REG_STS(a)	((a)->ioaddr + 0x04)	/* Status reg (RO) */
87#define I2C_REG_CTL(a)	((a)->ioaddr + 0x08)	/* Ctl reg */
88#define I2C_REG_CKL(a)	((a)->ioaddr + 0x0c)	/* Clock divider low */
89#define I2C_REG_CKH(a)	((a)->ioaddr + 0x10)	/* Clock divider high */
90#define I2C_REG_ADR(a)	((a)->ioaddr + 0x14)	/* I2C address */
91#define I2C_REG_RFL(a)	((a)->ioaddr + 0x18)	/* Rx FIFO level (RO) */
92#define I2C_REG_TFL(a)	((a)->ioaddr + 0x1c)	/* Tx FIFO level (RO) */
93#define I2C_REG_RXB(a)	((a)->ioaddr + 0x20)	/* Num of bytes Rx-ed (RO) */
94#define I2C_REG_TXB(a)	((a)->ioaddr + 0x24)	/* Num of bytes Tx-ed (RO) */
95#define I2C_REG_TXS(a)	((a)->ioaddr + 0x28)	/* Tx slave FIFO (RO) */
96#define I2C_REG_STFL(a)	((a)->ioaddr + 0x2c)	/* Tx slave FIFO level (RO) */
97
98static inline int wait_timeout(struct i2c_pnx_algo_data *data)
99{
100	long timeout = data->timeout;
101	while (timeout > 0 &&
102			(ioread32(I2C_REG_STS(data)) & mstatus_active)) {
103		mdelay(1);
104		timeout--;
105	}
106	return (timeout <= 0);
107}
108
109static inline int wait_reset(struct i2c_pnx_algo_data *data)
110{
111	long timeout = data->timeout;
112	while (timeout > 0 &&
113			(ioread32(I2C_REG_CTL(data)) & mcntrl_reset)) {
114		mdelay(1);
115		timeout--;
116	}
117	return (timeout <= 0);
118}
119
120static inline void i2c_pnx_arm_timer(struct i2c_pnx_algo_data *alg_data)
121{
122	struct timer_list *timer = &alg_data->mif.timer;
123	unsigned long expires = msecs_to_jiffies(alg_data->timeout);
124
125	if (expires <= 1)
126		expires = 2;
127
128	del_timer_sync(timer);
129
130	dev_dbg(&alg_data->adapter.dev, "Timer armed at %lu plus %lu jiffies.\n",
131		jiffies, expires);
132
133	timer->expires = jiffies + expires;
134
135	add_timer(timer);
136}
137
138/**
139 * i2c_pnx_start - start a device
140 * @slave_addr:		slave address
141 * @alg_data:		pointer to local driver data structure
142 *
143 * Generate a START signal in the desired mode.
144 */
145static int i2c_pnx_start(unsigned char slave_addr,
146	struct i2c_pnx_algo_data *alg_data)
147{
148	dev_dbg(&alg_data->adapter.dev, "%s(): addr 0x%x mode %d\n", __func__,
149		slave_addr, alg_data->mif.mode);
150
151	/* Check for 7 bit slave addresses only */
152	if (slave_addr & ~0x7f) {
153		dev_err(&alg_data->adapter.dev,
154			"%s: Invalid slave address %x. Only 7-bit addresses are supported\n",
155			alg_data->adapter.name, slave_addr);
156		return -EINVAL;
157	}
158
159	/* First, make sure bus is idle */
160	if (wait_timeout(alg_data)) {
161		/* Somebody else is monopolizing the bus */
162		dev_err(&alg_data->adapter.dev,
163			"%s: Bus busy. Slave addr = %02x, cntrl = %x, stat = %x\n",
164			alg_data->adapter.name, slave_addr,
165			ioread32(I2C_REG_CTL(alg_data)),
166			ioread32(I2C_REG_STS(alg_data)));
167		return -EBUSY;
168	} else if (ioread32(I2C_REG_STS(alg_data)) & mstatus_afi) {
169		/* Sorry, we lost the bus */
170		dev_err(&alg_data->adapter.dev,
171		        "%s: Arbitration failure. Slave addr = %02x\n",
172			alg_data->adapter.name, slave_addr);
173		return -EIO;
174	}
175
176	/*
177	 * OK, I2C is enabled and we have the bus.
178	 * Clear the current TDI and AFI status flags.
179	 */
180	iowrite32(ioread32(I2C_REG_STS(alg_data)) | mstatus_tdi | mstatus_afi,
181		  I2C_REG_STS(alg_data));
182
183	dev_dbg(&alg_data->adapter.dev, "%s(): sending %#x\n", __func__,
184		(slave_addr << 1) | start_bit | alg_data->mif.mode);
185
186	/* Write the slave address, START bit and R/W bit */
187	iowrite32((slave_addr << 1) | start_bit | alg_data->mif.mode,
188		  I2C_REG_TX(alg_data));
189
190	dev_dbg(&alg_data->adapter.dev, "%s(): exit\n", __func__);
191
192	return 0;
193}
194
195/**
196 * i2c_pnx_stop - stop a device
197 * @alg_data:		pointer to local driver data structure
198 *
199 * Generate a STOP signal to terminate the master transaction.
200 */
201static void i2c_pnx_stop(struct i2c_pnx_algo_data *alg_data)
202{
203	/* Only 1 msec max timeout due to interrupt context */
204	long timeout = 1000;
205
206	dev_dbg(&alg_data->adapter.dev, "%s(): entering: stat = %04x.\n",
207		__func__, ioread32(I2C_REG_STS(alg_data)));
208
209	/* Write a STOP bit to TX FIFO */
210	iowrite32(0xff | stop_bit, I2C_REG_TX(alg_data));
211
212	/* Wait until the STOP is seen. */
213	while (timeout > 0 &&
214	       (ioread32(I2C_REG_STS(alg_data)) & mstatus_active)) {
215		/* may be called from interrupt context */
216		udelay(1);
217		timeout--;
218	}
219
220	dev_dbg(&alg_data->adapter.dev, "%s(): exiting: stat = %04x.\n",
221		__func__, ioread32(I2C_REG_STS(alg_data)));
222}
223
224/**
225 * i2c_pnx_master_xmit - transmit data to slave
226 * @alg_data:		pointer to local driver data structure
227 *
228 * Sends one byte of data to the slave
229 */
230static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data)
231{
232	u32 val;
233
234	dev_dbg(&alg_data->adapter.dev, "%s(): entering: stat = %04x.\n",
235		__func__, ioread32(I2C_REG_STS(alg_data)));
236
237	if (alg_data->mif.len > 0) {
238		/* We still have something to talk about... */
239		val = *alg_data->mif.buf++;
240
241		if (alg_data->mif.len == 1)
242			val |= stop_bit;
243
244		alg_data->mif.len--;
245		iowrite32(val, I2C_REG_TX(alg_data));
246
247		dev_dbg(&alg_data->adapter.dev, "%s(): xmit %#x [%d]\n",
248			__func__, val, alg_data->mif.len + 1);
249
250		if (alg_data->mif.len == 0) {
251			if (alg_data->last) {
252				/* Wait until the STOP is seen. */
253				if (wait_timeout(alg_data))
254					dev_err(&alg_data->adapter.dev,
255						"The bus is still active after timeout\n");
256			}
257			/* Disable master interrupts */
258			iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
259				~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
260				  I2C_REG_CTL(alg_data));
261
262			del_timer_sync(&alg_data->mif.timer);
263
264			dev_dbg(&alg_data->adapter.dev,
265				"%s(): Waking up xfer routine.\n",
266				__func__);
267
268			complete(&alg_data->mif.complete);
269		}
270	} else if (alg_data->mif.len == 0) {
271		/* zero-sized transfer */
272		i2c_pnx_stop(alg_data);
273
274		/* Disable master interrupts. */
275		iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
276			~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
277			  I2C_REG_CTL(alg_data));
278
279		/* Stop timer. */
280		del_timer_sync(&alg_data->mif.timer);
281		dev_dbg(&alg_data->adapter.dev,
282			"%s(): Waking up xfer routine after zero-xfer.\n",
283			__func__);
284
285		complete(&alg_data->mif.complete);
286	}
287
288	dev_dbg(&alg_data->adapter.dev, "%s(): exiting: stat = %04x.\n",
289		__func__, ioread32(I2C_REG_STS(alg_data)));
290
291	return 0;
292}
293
294/**
295 * i2c_pnx_master_rcv - receive data from slave
296 * @alg_data:		pointer to local driver data structure
297 *
298 * Reads one byte data from the slave
299 */
300static int i2c_pnx_master_rcv(struct i2c_pnx_algo_data *alg_data)
301{
302	unsigned int val = 0;
303	u32 ctl = 0;
304
305	dev_dbg(&alg_data->adapter.dev, "%s(): entering: stat = %04x.\n",
306		__func__, ioread32(I2C_REG_STS(alg_data)));
307
308	/* Check, whether there is already data,
309	 * or we didn't 'ask' for it yet.
310	 */
311	if (ioread32(I2C_REG_STS(alg_data)) & mstatus_rfe) {
312		/* 'Asking' is done asynchronously, e.g. dummy TX of several
313		 * bytes is done before the first actual RX arrives in FIFO.
314		 * Therefore, ordered bytes (via TX) are counted separately.
315		 */
316		if (alg_data->mif.order) {
317			dev_dbg(&alg_data->adapter.dev,
318				"%s(): Write dummy data to fill Rx-fifo...\n",
319				__func__);
320
321			if (alg_data->mif.order == 1) {
322				/* Last byte, do not acknowledge next rcv. */
323				val |= stop_bit;
324
325				/*
326				 * Enable interrupt RFDAIE (data in Rx fifo),
327				 * and disable DRMIE (need data for Tx)
328				 */
329				ctl = ioread32(I2C_REG_CTL(alg_data));
330				ctl |= mcntrl_rffie | mcntrl_daie;
331				ctl &= ~mcntrl_drmie;
332				iowrite32(ctl, I2C_REG_CTL(alg_data));
333			}
334
335			/*
336			 * Now we'll 'ask' for data:
337			 * For each byte we want to receive, we must
338			 * write a (dummy) byte to the Tx-FIFO.
339			 */
340			iowrite32(val, I2C_REG_TX(alg_data));
341			alg_data->mif.order--;
342		}
343		return 0;
344	}
345
346	/* Handle data. */
347	if (alg_data->mif.len > 0) {
348		val = ioread32(I2C_REG_RX(alg_data));
349		*alg_data->mif.buf++ = (u8) (val & 0xff);
350		dev_dbg(&alg_data->adapter.dev, "%s(): rcv 0x%x [%d]\n",
351			__func__, val, alg_data->mif.len);
352
353		alg_data->mif.len--;
354		if (alg_data->mif.len == 0) {
355			if (alg_data->last)
356				/* Wait until the STOP is seen. */
357				if (wait_timeout(alg_data))
358					dev_err(&alg_data->adapter.dev,
359						"The bus is still active after timeout\n");
360
361			/* Disable master interrupts */
362			ctl = ioread32(I2C_REG_CTL(alg_data));
363			ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
364				 mcntrl_drmie | mcntrl_daie);
365			iowrite32(ctl, I2C_REG_CTL(alg_data));
366
367			/* Kill timer. */
368			del_timer_sync(&alg_data->mif.timer);
369			complete(&alg_data->mif.complete);
370		}
371	}
372
373	dev_dbg(&alg_data->adapter.dev, "%s(): exiting: stat = %04x.\n",
374		__func__, ioread32(I2C_REG_STS(alg_data)));
375
376	return 0;
377}
378
379static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id)
380{
381	struct i2c_pnx_algo_data *alg_data = dev_id;
382	u32 stat, ctl;
383
384	dev_dbg(&alg_data->adapter.dev,
385		"%s(): mstat = %x mctrl = %x, mode = %d\n",
386		__func__,
387		ioread32(I2C_REG_STS(alg_data)),
388		ioread32(I2C_REG_CTL(alg_data)),
389		alg_data->mif.mode);
390	stat = ioread32(I2C_REG_STS(alg_data));
391
392	/* let's see what kind of event this is */
393	if (stat & mstatus_afi) {
394		/* We lost arbitration in the midst of a transfer */
395		alg_data->mif.ret = -EIO;
396
397		/* Disable master interrupts. */
398		ctl = ioread32(I2C_REG_CTL(alg_data));
399		ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
400			 mcntrl_drmie);
401		iowrite32(ctl, I2C_REG_CTL(alg_data));
402
403		/* Stop timer, to prevent timeout. */
404		del_timer_sync(&alg_data->mif.timer);
405		complete(&alg_data->mif.complete);
406	} else if (stat & mstatus_nai) {
407		/* Slave did not acknowledge, generate a STOP */
408		dev_dbg(&alg_data->adapter.dev,
409			"%s(): Slave did not acknowledge, generating a STOP.\n",
410			__func__);
411		i2c_pnx_stop(alg_data);
412
413		/* Disable master interrupts. */
414		ctl = ioread32(I2C_REG_CTL(alg_data));
415		ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
416			 mcntrl_drmie);
417		iowrite32(ctl, I2C_REG_CTL(alg_data));
418
419		/* Our return value. */
420		alg_data->mif.ret = -EIO;
421
422		/* Stop timer, to prevent timeout. */
423		del_timer_sync(&alg_data->mif.timer);
424		complete(&alg_data->mif.complete);
425	} else {
426		/*
427		 * Two options:
428		 * - Master Tx needs data.
429		 * - There is data in the Rx-fifo
430		 * The latter is only the case if we have requested for data,
431		 * via a dummy write. (See 'i2c_pnx_master_rcv'.)
432		 * We therefore check, as a sanity check, whether that interrupt
433		 * has been enabled.
434		 */
435		if ((stat & mstatus_drmi) || !(stat & mstatus_rfe)) {
436			if (alg_data->mif.mode == I2C_SMBUS_WRITE) {
437				i2c_pnx_master_xmit(alg_data);
438			} else if (alg_data->mif.mode == I2C_SMBUS_READ) {
439				i2c_pnx_master_rcv(alg_data);
440			}
441		}
442	}
443
444	/* Clear TDI and AFI bits */
445	stat = ioread32(I2C_REG_STS(alg_data));
446	iowrite32(stat | mstatus_tdi | mstatus_afi, I2C_REG_STS(alg_data));
447
448	dev_dbg(&alg_data->adapter.dev,
449		"%s(): exiting, stat = %x ctrl = %x.\n",
450		 __func__, ioread32(I2C_REG_STS(alg_data)),
451		 ioread32(I2C_REG_CTL(alg_data)));
452
453	return IRQ_HANDLED;
454}
455
456static void i2c_pnx_timeout(struct timer_list *t)
457{
458	struct i2c_pnx_algo_data *alg_data = from_timer(alg_data, t, mif.timer);
459	u32 ctl;
460
461	dev_err(&alg_data->adapter.dev,
462		"Master timed out. stat = %04x, cntrl = %04x. Resetting master...\n",
463		ioread32(I2C_REG_STS(alg_data)),
464		ioread32(I2C_REG_CTL(alg_data)));
465
466	/* Reset master and disable interrupts */
467	ctl = ioread32(I2C_REG_CTL(alg_data));
468	ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie | mcntrl_drmie);
469	iowrite32(ctl, I2C_REG_CTL(alg_data));
470
471	ctl |= mcntrl_reset;
472	iowrite32(ctl, I2C_REG_CTL(alg_data));
473	wait_reset(alg_data);
474	alg_data->mif.ret = -EIO;
475	complete(&alg_data->mif.complete);
476}
477
478static inline void bus_reset_if_active(struct i2c_pnx_algo_data *alg_data)
479{
480	u32 stat;
481
482	if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_active) {
483		dev_err(&alg_data->adapter.dev,
484			"%s: Bus is still active after xfer. Reset it...\n",
485			alg_data->adapter.name);
486		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
487			  I2C_REG_CTL(alg_data));
488		wait_reset(alg_data);
489	} else if (!(stat & mstatus_rfe) || !(stat & mstatus_tfe)) {
490		/* If there is data in the fifo's after transfer,
491		 * flush fifo's by reset.
492		 */
493		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
494			  I2C_REG_CTL(alg_data));
495		wait_reset(alg_data);
496	} else if (stat & mstatus_nai) {
497		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
498			  I2C_REG_CTL(alg_data));
499		wait_reset(alg_data);
500	}
501}
502
503/**
504 * i2c_pnx_xfer - generic transfer entry point
505 * @adap:		pointer to I2C adapter structure
506 * @msgs:		array of messages
507 * @num:		number of messages
508 *
509 * Initiates the transfer
510 */
511static int
512i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
513{
514	struct i2c_msg *pmsg;
515	int rc = 0, completed = 0, i;
516	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
517	u32 stat;
518
519	dev_dbg(&alg_data->adapter.dev,
520		"%s(): entering: %d messages, stat = %04x.\n",
521		__func__, num, ioread32(I2C_REG_STS(alg_data)));
522
523	bus_reset_if_active(alg_data);
524
525	/* Process transactions in a loop. */
526	for (i = 0; rc >= 0 && i < num; i++) {
527		u8 addr;
528
529		pmsg = &msgs[i];
530		addr = pmsg->addr;
531
532		if (pmsg->flags & I2C_M_TEN) {
533			dev_err(&alg_data->adapter.dev,
534				"%s: 10 bits addr not supported!\n",
535				alg_data->adapter.name);
536			rc = -EINVAL;
537			break;
538		}
539
540		alg_data->mif.buf = pmsg->buf;
541		alg_data->mif.len = pmsg->len;
542		alg_data->mif.order = pmsg->len;
543		alg_data->mif.mode = (pmsg->flags & I2C_M_RD) ?
544			I2C_SMBUS_READ : I2C_SMBUS_WRITE;
545		alg_data->mif.ret = 0;
546		alg_data->last = (i == num - 1);
547
548		dev_dbg(&alg_data->adapter.dev, "%s(): mode %d, %d bytes\n",
549			__func__, alg_data->mif.mode, alg_data->mif.len);
550
551		i2c_pnx_arm_timer(alg_data);
552
553		/* initialize the completion var */
554		init_completion(&alg_data->mif.complete);
555
556		/* Enable master interrupt */
557		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_afie |
558				mcntrl_naie | mcntrl_drmie,
559			  I2C_REG_CTL(alg_data));
560
561		/* Put start-code and slave-address on the bus. */
562		rc = i2c_pnx_start(addr, alg_data);
563		if (rc < 0)
564			break;
565
566		/* Wait for completion */
567		wait_for_completion(&alg_data->mif.complete);
568
569		if (!(rc = alg_data->mif.ret))
570			completed++;
571		dev_dbg(&alg_data->adapter.dev,
572			"%s(): Complete, return code = %d.\n",
573			__func__, rc);
574
575		/* Clear TDI and AFI bits in case they are set. */
576		if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_tdi) {
577			dev_dbg(&alg_data->adapter.dev,
578				"%s: TDI still set... clearing now.\n",
579				alg_data->adapter.name);
580			iowrite32(stat, I2C_REG_STS(alg_data));
581		}
582		if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_afi) {
583			dev_dbg(&alg_data->adapter.dev,
584				"%s: AFI still set... clearing now.\n",
585				alg_data->adapter.name);
586			iowrite32(stat, I2C_REG_STS(alg_data));
587		}
588	}
589
590	bus_reset_if_active(alg_data);
591
592	/* Cleanup to be sure... */
593	alg_data->mif.buf = NULL;
594	alg_data->mif.len = 0;
595	alg_data->mif.order = 0;
596
597	dev_dbg(&alg_data->adapter.dev, "%s(): exiting, stat = %x\n",
598		__func__, ioread32(I2C_REG_STS(alg_data)));
599
600	if (completed != num)
601		return ((rc < 0) ? rc : -EREMOTEIO);
602
603	return num;
604}
605
606static u32 i2c_pnx_func(struct i2c_adapter *adapter)
607{
608	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
609}
610
611static const struct i2c_algorithm pnx_algorithm = {
612	.master_xfer = i2c_pnx_xfer,
613	.functionality = i2c_pnx_func,
614};
615
616static int i2c_pnx_controller_suspend(struct device *dev)
617{
618	struct i2c_pnx_algo_data *alg_data = dev_get_drvdata(dev);
619
620	clk_disable_unprepare(alg_data->clk);
621
622	return 0;
623}
624
625static int i2c_pnx_controller_resume(struct device *dev)
626{
627	struct i2c_pnx_algo_data *alg_data = dev_get_drvdata(dev);
628
629	return clk_prepare_enable(alg_data->clk);
630}
631
632static DEFINE_SIMPLE_DEV_PM_OPS(i2c_pnx_pm,
633				i2c_pnx_controller_suspend,
634				i2c_pnx_controller_resume);
635
636static int i2c_pnx_probe(struct platform_device *pdev)
637{
638	unsigned long tmp;
639	int ret = 0;
640	struct i2c_pnx_algo_data *alg_data;
641	unsigned long freq;
642	struct resource *res;
643	u32 speed = I2C_PNX_SPEED_KHZ_DEFAULT * 1000;
644
645	alg_data = devm_kzalloc(&pdev->dev, sizeof(*alg_data), GFP_KERNEL);
646	if (!alg_data)
647		return -ENOMEM;
648
649	platform_set_drvdata(pdev, alg_data);
650
651	alg_data->adapter.dev.parent = &pdev->dev;
652	alg_data->adapter.algo = &pnx_algorithm;
653	alg_data->adapter.algo_data = alg_data;
654	alg_data->adapter.nr = pdev->id;
655
656	alg_data->timeout = I2C_PNX_TIMEOUT_DEFAULT;
657#ifdef CONFIG_OF
658	alg_data->adapter.dev.of_node = of_node_get(pdev->dev.of_node);
659	if (pdev->dev.of_node) {
660		of_property_read_u32(pdev->dev.of_node, "clock-frequency",
661				     &speed);
662		/*
663		 * At this point, it is planned to add an OF timeout property.
664		 * As soon as there is a consensus about how to call and handle
665		 * this, sth. like the following can be put here:
666		 *
667		 * of_property_read_u32(pdev->dev.of_node, "timeout",
668		 *                      &alg_data->timeout);
669		 */
670	}
671#endif
672	alg_data->clk = devm_clk_get(&pdev->dev, NULL);
673	if (IS_ERR(alg_data->clk))
674		return PTR_ERR(alg_data->clk);
675
676	timer_setup(&alg_data->mif.timer, i2c_pnx_timeout, 0);
677
678	snprintf(alg_data->adapter.name, sizeof(alg_data->adapter.name),
679		 "%s", pdev->name);
680
681	/* Register I/O resource */
682	alg_data->ioaddr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
683	if (IS_ERR(alg_data->ioaddr))
684		return PTR_ERR(alg_data->ioaddr);
685
686	ret = clk_prepare_enable(alg_data->clk);
687	if (ret)
688		return ret;
689
690	freq = clk_get_rate(alg_data->clk);
691
692	/*
693	 * Clock Divisor High This value is the number of system clocks
694	 * the serial clock (SCL) will be high.
695	 * For example, if the system clock period is 50 ns and the maximum
696	 * desired serial period is 10000 ns (100 kHz), then CLKHI would be
697	 * set to 0.5*(f_sys/f_i2c)-2=0.5*(20e6/100e3)-2=98. The actual value
698	 * programmed into CLKHI will vary from this slightly due to
699	 * variations in the output pad's rise and fall times as well as
700	 * the deglitching filter length.
701	 */
702
703	tmp = (freq / speed) / 2 - 2;
704	if (tmp > 0x3FF)
705		tmp = 0x3FF;
706	iowrite32(tmp, I2C_REG_CKH(alg_data));
707	iowrite32(tmp, I2C_REG_CKL(alg_data));
708
709	iowrite32(mcntrl_reset, I2C_REG_CTL(alg_data));
710	if (wait_reset(alg_data)) {
711		ret = -ENODEV;
712		goto out_clock;
713	}
714	init_completion(&alg_data->mif.complete);
715
716	alg_data->irq = platform_get_irq(pdev, 0);
717	if (alg_data->irq < 0) {
718		ret = alg_data->irq;
719		goto out_clock;
720	}
721	ret = devm_request_irq(&pdev->dev, alg_data->irq, i2c_pnx_interrupt,
722			       0, pdev->name, alg_data);
723	if (ret)
724		goto out_clock;
725
726	/* Register this adapter with the I2C subsystem */
727	ret = i2c_add_numbered_adapter(&alg_data->adapter);
728	if (ret < 0)
729		goto out_clock;
730
731	dev_dbg(&pdev->dev, "%s: Master at %pap, irq %d.\n",
732		alg_data->adapter.name, &res->start, alg_data->irq);
733
734	return 0;
735
736out_clock:
737	clk_disable_unprepare(alg_data->clk);
738	return ret;
739}
740
741static void i2c_pnx_remove(struct platform_device *pdev)
742{
743	struct i2c_pnx_algo_data *alg_data = platform_get_drvdata(pdev);
744
745	i2c_del_adapter(&alg_data->adapter);
746	clk_disable_unprepare(alg_data->clk);
747}
748
749#ifdef CONFIG_OF
750static const struct of_device_id i2c_pnx_of_match[] = {
751	{ .compatible = "nxp,pnx-i2c" },
752	{ },
753};
754MODULE_DEVICE_TABLE(of, i2c_pnx_of_match);
755#endif
756
757static struct platform_driver i2c_pnx_driver = {
758	.driver = {
759		.name = "pnx-i2c",
760		.of_match_table = of_match_ptr(i2c_pnx_of_match),
761		.pm = pm_sleep_ptr(&i2c_pnx_pm),
762	},
763	.probe = i2c_pnx_probe,
764	.remove_new = i2c_pnx_remove,
765};
766
767static int __init i2c_adap_pnx_init(void)
768{
769	return platform_driver_register(&i2c_pnx_driver);
770}
771
772static void __exit i2c_adap_pnx_exit(void)
773{
774	platform_driver_unregister(&i2c_pnx_driver);
775}
776
777MODULE_AUTHOR("Vitaly Wool");
778MODULE_AUTHOR("Dennis Kovalev <source@mvista.com>");
779MODULE_DESCRIPTION("I2C driver for Philips IP3204-based I2C busses");
780MODULE_LICENSE("GPL");
781MODULE_ALIAS("platform:pnx-i2c");
782
783/* We need to make sure I2C is initialized before USB */
784subsys_initcall(i2c_adap_pnx_init);
785module_exit(i2c_adap_pnx_exit);
786