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