Pull remove-hotkey into release branch
[linux-2.6] / drivers / i2c / busses / i2c-s3c2410.c
1 /* linux/drivers/i2c/busses/i2c-s3c2410.c
2  *
3  * Copyright (C) 2004,2005 Simtec Electronics
4  *      Ben Dooks <ben@simtec.co.uk>
5  *
6  * S3C2410 I2C Controller
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21 */
22
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25
26 #include <linux/i2c.h>
27 #include <linux/i2c-id.h>
28 #include <linux/init.h>
29 #include <linux/time.h>
30 #include <linux/interrupt.h>
31 #include <linux/delay.h>
32 #include <linux/errno.h>
33 #include <linux/err.h>
34 #include <linux/platform_device.h>
35 #include <linux/clk.h>
36
37 #include <asm/hardware.h>
38 #include <asm/irq.h>
39 #include <asm/io.h>
40
41 #include <asm/arch/regs-gpio.h>
42 #include <asm/arch/regs-iic.h>
43 #include <asm/arch/iic.h>
44
45 /* i2c controller state */
46
47 enum s3c24xx_i2c_state {
48         STATE_IDLE,
49         STATE_START,
50         STATE_READ,
51         STATE_WRITE,
52         STATE_STOP
53 };
54
55 struct s3c24xx_i2c {
56         spinlock_t              lock;
57         wait_queue_head_t       wait;
58
59         struct i2c_msg          *msg;
60         unsigned int            msg_num;
61         unsigned int            msg_idx;
62         unsigned int            msg_ptr;
63
64         enum s3c24xx_i2c_state  state;
65
66         void __iomem            *regs;
67         struct clk              *clk;
68         struct device           *dev;
69         struct resource         *irq;
70         struct resource         *ioarea;
71         struct i2c_adapter      adap;
72 };
73
74 /* default platform data to use if not supplied in the platform_device
75 */
76
77 static struct s3c2410_platform_i2c s3c24xx_i2c_default_platform = {
78         .flags          = 0,
79         .slave_addr     = 0x10,
80         .bus_freq       = 100*1000,
81         .max_freq       = 400*1000,
82         .sda_delay      = S3C2410_IICLC_SDA_DELAY5 | S3C2410_IICLC_FILTER_ON,
83 };
84
85 /* s3c24xx_i2c_is2440()
86  *
87  * return true is this is an s3c2440
88 */
89
90 static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
91 {
92         struct platform_device *pdev = to_platform_device(i2c->dev);
93
94         return !strcmp(pdev->name, "s3c2440-i2c");
95 }
96
97
98 /* s3c24xx_i2c_get_platformdata
99  *
100  * get the platform data associated with the given device, or return
101  * the default if there is none
102 */
103
104 static inline struct s3c2410_platform_i2c *s3c24xx_i2c_get_platformdata(struct device *dev)
105 {
106         if (dev->platform_data != NULL)
107                 return (struct s3c2410_platform_i2c *)dev->platform_data;
108
109         return &s3c24xx_i2c_default_platform;
110 }
111
112 /* s3c24xx_i2c_master_complete
113  *
114  * complete the message and wake up the caller, using the given return code,
115  * or zero to mean ok.
116 */
117
118 static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret)
119 {
120         dev_dbg(i2c->dev, "master_complete %d\n", ret);
121
122         i2c->msg_ptr = 0;
123         i2c->msg = NULL;
124         i2c->msg_idx ++;
125         i2c->msg_num = 0;
126         if (ret)
127                 i2c->msg_idx = ret;
128
129         wake_up(&i2c->wait);
130 }
131
132 static inline void s3c24xx_i2c_disable_ack(struct s3c24xx_i2c *i2c)
133 {
134         unsigned long tmp;
135         
136         tmp = readl(i2c->regs + S3C2410_IICCON);
137         writel(tmp & ~S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON);
138
139 }
140
141 static inline void s3c24xx_i2c_enable_ack(struct s3c24xx_i2c *i2c)
142 {
143         unsigned long tmp;
144         
145         tmp = readl(i2c->regs + S3C2410_IICCON);
146         writel(tmp | S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON);
147
148 }
149
150 /* irq enable/disable functions */
151
152 static inline void s3c24xx_i2c_disable_irq(struct s3c24xx_i2c *i2c)
153 {
154         unsigned long tmp;
155         
156         tmp = readl(i2c->regs + S3C2410_IICCON);
157         writel(tmp & ~S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
158 }
159
160 static inline void s3c24xx_i2c_enable_irq(struct s3c24xx_i2c *i2c)
161 {
162         unsigned long tmp;
163         
164         tmp = readl(i2c->regs + S3C2410_IICCON);
165         writel(tmp | S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
166 }
167
168
169 /* s3c24xx_i2c_message_start
170  *
171  * put the start of a message onto the bus 
172 */
173
174 static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c, 
175                                       struct i2c_msg *msg)
176 {
177         unsigned int addr = (msg->addr & 0x7f) << 1;
178         unsigned long stat;
179         unsigned long iiccon;
180
181         stat = 0;
182         stat |=  S3C2410_IICSTAT_TXRXEN;
183
184         if (msg->flags & I2C_M_RD) {
185                 stat |= S3C2410_IICSTAT_MASTER_RX;
186                 addr |= 1;
187         } else
188                 stat |= S3C2410_IICSTAT_MASTER_TX;
189
190         if (msg->flags & I2C_M_REV_DIR_ADDR)
191                 addr ^= 1;
192
193         // todo - check for wether ack wanted or not
194         s3c24xx_i2c_enable_ack(i2c);
195
196         iiccon = readl(i2c->regs + S3C2410_IICCON);
197         writel(stat, i2c->regs + S3C2410_IICSTAT);
198         
199         dev_dbg(i2c->dev, "START: %08lx to IICSTAT, %02x to DS\n", stat, addr);
200         writeb(addr, i2c->regs + S3C2410_IICDS);
201         
202         // delay a bit and reset iiccon before setting start (per samsung)
203         udelay(1);
204         dev_dbg(i2c->dev, "iiccon, %08lx\n", iiccon);
205         writel(iiccon, i2c->regs + S3C2410_IICCON);
206         
207         stat |=  S3C2410_IICSTAT_START;
208         writel(stat, i2c->regs + S3C2410_IICSTAT);
209 }
210
211 static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret)
212 {
213         unsigned long iicstat = readl(i2c->regs + S3C2410_IICSTAT);
214
215         dev_dbg(i2c->dev, "STOP\n");
216
217         /* stop the transfer */
218         iicstat &= ~ S3C2410_IICSTAT_START;
219         writel(iicstat, i2c->regs + S3C2410_IICSTAT);
220         
221         i2c->state = STATE_STOP;
222         
223         s3c24xx_i2c_master_complete(i2c, ret);
224         s3c24xx_i2c_disable_irq(i2c);
225 }
226
227 /* helper functions to determine the current state in the set of
228  * messages we are sending */
229
230 /* is_lastmsg()
231  *
232  * returns TRUE if the current message is the last in the set 
233 */
234
235 static inline int is_lastmsg(struct s3c24xx_i2c *i2c)
236 {
237         return i2c->msg_idx >= (i2c->msg_num - 1);
238 }
239
240 /* is_msglast
241  *
242  * returns TRUE if we this is the last byte in the current message
243 */
244
245 static inline int is_msglast(struct s3c24xx_i2c *i2c)
246 {
247         return i2c->msg_ptr == i2c->msg->len-1;
248 }
249
250 /* is_msgend
251  *
252  * returns TRUE if we reached the end of the current message
253 */
254
255 static inline int is_msgend(struct s3c24xx_i2c *i2c)
256 {
257         return i2c->msg_ptr >= i2c->msg->len;
258 }
259
260 /* i2s_s3c_irq_nextbyte
261  *
262  * process an interrupt and work out what to do
263  */
264
265 static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat)
266 {
267         unsigned long tmp;
268         unsigned char byte;
269         int ret = 0;
270
271         switch (i2c->state) {
272
273         case STATE_IDLE:
274                 dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __FUNCTION__);
275                 goto out;
276                 break;
277
278         case STATE_STOP:
279                 dev_err(i2c->dev, "%s: called in STATE_STOP\n", __FUNCTION__);
280                 s3c24xx_i2c_disable_irq(i2c);           
281                 goto out_ack;
282
283         case STATE_START:
284                 /* last thing we did was send a start condition on the
285                  * bus, or started a new i2c message
286                  */
287                 
288                 if (iicstat  & S3C2410_IICSTAT_LASTBIT &&
289                     !(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
290                         /* ack was not received... */
291
292                         dev_dbg(i2c->dev, "ack was not received\n");
293                         s3c24xx_i2c_stop(i2c, -EREMOTEIO);
294                         goto out_ack;
295                 }
296
297                 if (i2c->msg->flags & I2C_M_RD)
298                         i2c->state = STATE_READ;
299                 else
300                         i2c->state = STATE_WRITE;
301
302                 /* terminate the transfer if there is nothing to do
303                  * (used by the i2c probe to find devices */
304
305                 if (is_lastmsg(i2c) && i2c->msg->len == 0) {
306                         s3c24xx_i2c_stop(i2c, 0);
307                         goto out_ack;
308                 }
309
310                 if (i2c->state == STATE_READ)
311                         goto prepare_read;
312
313                 /* fall through to the write state, as we will need to 
314                  * send a byte as well */
315
316         case STATE_WRITE:
317                 /* we are writing data to the device... check for the
318                  * end of the message, and if so, work out what to do
319                  */
320
321         retry_write:
322                 if (!is_msgend(i2c)) {
323                         byte = i2c->msg->buf[i2c->msg_ptr++];
324                         writeb(byte, i2c->regs + S3C2410_IICDS);
325                         
326                 } else if (!is_lastmsg(i2c)) {
327                         /* we need to go to the next i2c message */
328
329                         dev_dbg(i2c->dev, "WRITE: Next Message\n");
330
331                         i2c->msg_ptr = 0;
332                         i2c->msg_idx ++;
333                         i2c->msg++;
334                         
335                         /* check to see if we need to do another message */
336                         if (i2c->msg->flags & I2C_M_NOSTART) {
337
338                                 if (i2c->msg->flags & I2C_M_RD) {
339                                         /* cannot do this, the controller
340                                          * forces us to send a new START
341                                          * when we change direction */
342
343                                         s3c24xx_i2c_stop(i2c, -EINVAL);
344                                 }
345
346                                 goto retry_write;
347                         } else {
348                         
349                                 /* send the new start */
350                                 s3c24xx_i2c_message_start(i2c, i2c->msg);
351                                 i2c->state = STATE_START;
352                         }
353
354                 } else {
355                         /* send stop */
356
357                         s3c24xx_i2c_stop(i2c, 0);
358                 }
359                 break;
360
361         case STATE_READ:
362                 /* we have a byte of data in the data register, do 
363                  * something with it, and then work out wether we are
364                  * going to do any more read/write
365                  */
366
367                 if (!(i2c->msg->flags & I2C_M_IGNORE_NAK) &&
368                     !(is_msglast(i2c) && is_lastmsg(i2c))) {
369
370                         if (iicstat & S3C2410_IICSTAT_LASTBIT) {
371                                 dev_dbg(i2c->dev, "READ: No Ack\n");
372
373                                 s3c24xx_i2c_stop(i2c, -ECONNREFUSED);
374                                 goto out_ack;
375                         }
376                 }
377
378                 byte = readb(i2c->regs + S3C2410_IICDS);
379                 i2c->msg->buf[i2c->msg_ptr++] = byte;
380
381         prepare_read:
382                 if (is_msglast(i2c)) {
383                         /* last byte of buffer */
384
385                         if (is_lastmsg(i2c))
386                                 s3c24xx_i2c_disable_ack(i2c);
387                         
388                 } else if (is_msgend(i2c)) {
389                         /* ok, we've read the entire buffer, see if there
390                          * is anything else we need to do */
391
392                         if (is_lastmsg(i2c)) {
393                                 /* last message, send stop and complete */
394                                 dev_dbg(i2c->dev, "READ: Send Stop\n");
395
396                                 s3c24xx_i2c_stop(i2c, 0);
397                         } else {
398                                 /* go to the next transfer */
399                                 dev_dbg(i2c->dev, "READ: Next Transfer\n");
400
401                                 i2c->msg_ptr = 0;
402                                 i2c->msg_idx++;
403                                 i2c->msg++;
404                         }
405                 }
406
407                 break;
408         }
409
410         /* acknowlegde the IRQ and get back on with the work */
411
412  out_ack:
413         tmp = readl(i2c->regs + S3C2410_IICCON);        
414         tmp &= ~S3C2410_IICCON_IRQPEND;
415         writel(tmp, i2c->regs + S3C2410_IICCON);
416  out:
417         return ret;
418 }
419
420 /* s3c24xx_i2c_irq
421  *
422  * top level IRQ servicing routine
423 */
424
425 static irqreturn_t s3c24xx_i2c_irq(int irqno, void *dev_id)
426 {
427         struct s3c24xx_i2c *i2c = dev_id;
428         unsigned long status;
429         unsigned long tmp;
430
431         status = readl(i2c->regs + S3C2410_IICSTAT);
432
433         if (status & S3C2410_IICSTAT_ARBITR) {
434                 // deal with arbitration loss
435                 dev_err(i2c->dev, "deal with arbitration loss\n");
436         }
437
438         if (i2c->state == STATE_IDLE) {
439                 dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n");
440
441                 tmp = readl(i2c->regs + S3C2410_IICCON);        
442                 tmp &= ~S3C2410_IICCON_IRQPEND;
443                 writel(tmp, i2c->regs +  S3C2410_IICCON);
444                 goto out;
445         }
446         
447         /* pretty much this leaves us with the fact that we've
448          * transmitted or received whatever byte we last sent */
449
450         i2s_s3c_irq_nextbyte(i2c, status);
451
452  out:
453         return IRQ_HANDLED;
454 }
455
456
457 /* s3c24xx_i2c_set_master
458  *
459  * get the i2c bus for a master transaction
460 */
461
462 static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c)
463 {
464         unsigned long iicstat;
465         int timeout = 400;
466
467         while (timeout-- > 0) {
468                 iicstat = readl(i2c->regs + S3C2410_IICSTAT);
469                 
470                 if (!(iicstat & S3C2410_IICSTAT_BUSBUSY))
471                         return 0;
472
473                 msleep(1);
474         }
475
476         dev_dbg(i2c->dev, "timeout: GPEDAT is %08x\n",
477                 __raw_readl(S3C2410_GPEDAT));
478
479         return -ETIMEDOUT;
480 }
481
482 /* s3c24xx_i2c_doxfer
483  *
484  * this starts an i2c transfer
485 */
486
487 static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, struct i2c_msg *msgs, int num)
488 {
489         unsigned long timeout;
490         int ret;
491
492         ret = s3c24xx_i2c_set_master(i2c);
493         if (ret != 0) {
494                 dev_err(i2c->dev, "cannot get bus (error %d)\n", ret);
495                 ret = -EAGAIN;
496                 goto out;
497         }
498
499         spin_lock_irq(&i2c->lock);
500
501         i2c->msg     = msgs;
502         i2c->msg_num = num;
503         i2c->msg_ptr = 0;
504         i2c->msg_idx = 0;
505         i2c->state   = STATE_START;
506
507         s3c24xx_i2c_enable_irq(i2c);
508         s3c24xx_i2c_message_start(i2c, msgs);
509         spin_unlock_irq(&i2c->lock);
510         
511         timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
512
513         ret = i2c->msg_idx;
514
515         /* having these next two as dev_err() makes life very 
516          * noisy when doing an i2cdetect */
517
518         if (timeout == 0)
519                 dev_dbg(i2c->dev, "timeout\n");
520         else if (ret != num)
521                 dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
522
523         /* ensure the stop has been through the bus */
524
525         msleep(1);
526
527  out:
528         return ret;
529 }
530
531 /* s3c24xx_i2c_xfer
532  *
533  * first port of call from the i2c bus code when an message needs
534  * transferring across the i2c bus.
535 */
536
537 static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
538                         struct i2c_msg *msgs, int num)
539 {
540         struct s3c24xx_i2c *i2c = (struct s3c24xx_i2c *)adap->algo_data;
541         int retry;
542         int ret;
543
544         for (retry = 0; retry < adap->retries; retry++) {
545
546                 ret = s3c24xx_i2c_doxfer(i2c, msgs, num);
547
548                 if (ret != -EAGAIN)
549                         return ret;
550
551                 dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry);
552
553                 udelay(100);
554         }
555
556         return -EREMOTEIO;
557 }
558
559 /* declare our i2c functionality */
560 static u32 s3c24xx_i2c_func(struct i2c_adapter *adap)
561 {
562         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
563 }
564
565 /* i2c bus registration info */
566
567 static const struct i2c_algorithm s3c24xx_i2c_algorithm = {
568         .master_xfer            = s3c24xx_i2c_xfer,
569         .functionality          = s3c24xx_i2c_func,
570 };
571
572 static struct s3c24xx_i2c s3c24xx_i2c = {
573         .lock   = SPIN_LOCK_UNLOCKED,
574         .wait   = __WAIT_QUEUE_HEAD_INITIALIZER(s3c24xx_i2c.wait),
575         .adap   = {
576                 .name                   = "s3c2410-i2c",
577                 .owner                  = THIS_MODULE,
578                 .algo                   = &s3c24xx_i2c_algorithm,
579                 .retries                = 2,
580                 .class                  = I2C_CLASS_HWMON,
581         },
582 };
583
584 /* s3c24xx_i2c_calcdivisor
585  *
586  * return the divisor settings for a given frequency
587 */
588
589 static int s3c24xx_i2c_calcdivisor(unsigned long clkin, unsigned int wanted,
590                                    unsigned int *div1, unsigned int *divs)
591 {
592         unsigned int calc_divs = clkin / wanted;
593         unsigned int calc_div1;
594
595         if (calc_divs > (16*16))
596                 calc_div1 = 512;
597         else
598                 calc_div1 = 16;
599
600         calc_divs += calc_div1-1;
601         calc_divs /= calc_div1;
602
603         if (calc_divs == 0)
604                 calc_divs = 1;
605         if (calc_divs > 17)
606                 calc_divs = 17;
607
608         *divs = calc_divs;
609         *div1 = calc_div1;
610
611         return clkin / (calc_divs * calc_div1);
612 }
613
614 /* freq_acceptable
615  *
616  * test wether a frequency is within the acceptable range of error
617 */
618
619 static inline int freq_acceptable(unsigned int freq, unsigned int wanted)
620 {
621         int diff = freq - wanted;
622
623         return (diff >= -2 && diff <= 2);
624 }
625
626 /* s3c24xx_i2c_getdivisor
627  *
628  * work out a divisor for the user requested frequency setting,
629  * either by the requested frequency, or scanning the acceptable
630  * range of frequencies until something is found
631 */
632
633 static int s3c24xx_i2c_getdivisor(struct s3c24xx_i2c *i2c,
634                                   struct s3c2410_platform_i2c *pdata,
635                                   unsigned long *iicon,
636                                   unsigned int *got)
637 {
638         unsigned long clkin = clk_get_rate(i2c->clk);
639         
640         unsigned int divs, div1;
641         int freq;
642         int start, end;
643
644         clkin /= 1000;          /* clkin now in KHz */
645      
646         dev_dbg(i2c->dev,  "pdata %p, freq %lu %lu..%lu\n",
647                  pdata, pdata->bus_freq, pdata->min_freq, pdata->max_freq);
648
649         if (pdata->bus_freq != 0) {
650                 freq = s3c24xx_i2c_calcdivisor(clkin, pdata->bus_freq/1000,
651                                                &div1, &divs);
652                 if (freq_acceptable(freq, pdata->bus_freq/1000))
653                         goto found;
654         }
655
656         /* ok, we may have to search for something suitable... */
657
658         start = (pdata->max_freq == 0) ? pdata->bus_freq : pdata->max_freq;
659         end = pdata->min_freq;
660
661         start /= 1000;
662         end /= 1000;
663
664         /* search loop... */
665
666         for (; start > end; start--) {
667                 freq = s3c24xx_i2c_calcdivisor(clkin, start, &div1, &divs);
668                 if (freq_acceptable(freq, start))
669                         goto found;
670         }
671
672         /* cannot find frequency spec */
673
674         return -EINVAL;
675
676  found:
677         *got = freq;
678         *iicon |= (divs-1);
679         *iicon |= (div1 == 512) ? S3C2410_IICCON_TXDIV_512 : 0;
680         return 0;
681 }
682
683 /* s3c24xx_i2c_init
684  *
685  * initialise the controller, set the IO lines and frequency 
686 */
687
688 static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
689 {
690         unsigned long iicon = S3C2410_IICCON_IRQEN | S3C2410_IICCON_ACKEN;
691         struct s3c2410_platform_i2c *pdata;
692         unsigned int freq;
693
694         /* get the plafrom data */
695
696         pdata = s3c24xx_i2c_get_platformdata(i2c->adap.dev.parent);
697
698         /* inititalise the gpio */
699
700         s3c2410_gpio_cfgpin(S3C2410_GPE15, S3C2410_GPE15_IICSDA);
701         s3c2410_gpio_cfgpin(S3C2410_GPE14, S3C2410_GPE14_IICSCL);
702
703         /* write slave address */
704         
705         writeb(pdata->slave_addr, i2c->regs + S3C2410_IICADD);
706
707         dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr);
708
709         /* we need to work out the divisors for the clock... */
710
711         if (s3c24xx_i2c_getdivisor(i2c, pdata, &iicon, &freq) != 0) {
712                 dev_err(i2c->dev, "cannot meet bus frequency required\n");
713                 return -EINVAL;
714         }
715
716         /* todo - check that the i2c lines aren't being dragged anywhere */
717
718         dev_info(i2c->dev, "bus frequency set to %d KHz\n", freq);
719         dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02lx\n", iicon);
720         
721         writel(iicon, i2c->regs + S3C2410_IICCON);
722
723         /* check for s3c2440 i2c controller  */
724
725         if (s3c24xx_i2c_is2440(i2c)) {
726                 dev_dbg(i2c->dev, "S3C2440_IICLC=%08x\n", pdata->sda_delay);
727
728                 writel(pdata->sda_delay, i2c->regs + S3C2440_IICLC);
729         }
730
731         return 0;
732 }
733
734 static void s3c24xx_i2c_free(struct s3c24xx_i2c *i2c)
735 {
736         if (i2c->clk != NULL && !IS_ERR(i2c->clk)) {
737                 clk_disable(i2c->clk);
738                 clk_put(i2c->clk);
739                 i2c->clk = NULL;
740         }
741
742         if (i2c->regs != NULL) {
743                 iounmap(i2c->regs);
744                 i2c->regs = NULL;
745         }
746
747         if (i2c->ioarea != NULL) {
748                 release_resource(i2c->ioarea);
749                 kfree(i2c->ioarea);
750                 i2c->ioarea = NULL;
751         }
752 }
753
754 /* s3c24xx_i2c_probe
755  *
756  * called by the bus driver when a suitable device is found
757 */
758
759 static int s3c24xx_i2c_probe(struct platform_device *pdev)
760 {
761         struct s3c24xx_i2c *i2c = &s3c24xx_i2c;
762         struct resource *res;
763         int ret;
764
765         /* find the clock and enable it */
766
767         i2c->dev = &pdev->dev;
768         i2c->clk = clk_get(&pdev->dev, "i2c");
769         if (IS_ERR(i2c->clk)) {
770                 dev_err(&pdev->dev, "cannot get clock\n");
771                 ret = -ENOENT;
772                 goto out;
773         }
774
775         dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);
776
777         clk_enable(i2c->clk);
778
779         /* map the registers */
780
781         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
782         if (res == NULL) {
783                 dev_err(&pdev->dev, "cannot find IO resource\n");
784                 ret = -ENOENT;
785                 goto out;
786         }
787
788         i2c->ioarea = request_mem_region(res->start, (res->end-res->start)+1,
789                                          pdev->name);
790
791         if (i2c->ioarea == NULL) {
792                 dev_err(&pdev->dev, "cannot request IO\n");
793                 ret = -ENXIO;
794                 goto out;
795         }
796
797         i2c->regs = ioremap(res->start, (res->end-res->start)+1);
798
799         if (i2c->regs == NULL) {
800                 dev_err(&pdev->dev, "cannot map IO\n");
801                 ret = -ENXIO;
802                 goto out;
803         }
804
805         dev_dbg(&pdev->dev, "registers %p (%p, %p)\n", i2c->regs, i2c->ioarea, res);
806
807         /* setup info block for the i2c core */
808
809         i2c->adap.algo_data = i2c;
810         i2c->adap.dev.parent = &pdev->dev;
811
812         /* initialise the i2c controller */
813
814         ret = s3c24xx_i2c_init(i2c);
815         if (ret != 0)
816                 goto out;
817
818         /* find the IRQ for this unit (note, this relies on the init call to
819          * ensure no current IRQs pending 
820          */
821
822         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
823         if (res == NULL) {
824                 dev_err(&pdev->dev, "cannot find IRQ\n");
825                 ret = -ENOENT;
826                 goto out;
827         }
828
829         ret = request_irq(res->start, s3c24xx_i2c_irq, IRQF_DISABLED,
830                           pdev->name, i2c);
831
832         if (ret != 0) {
833                 dev_err(&pdev->dev, "cannot claim IRQ\n");
834                 goto out;
835         }
836
837         i2c->irq = res;
838                 
839         dev_dbg(&pdev->dev, "irq resource %p (%ld)\n", res, res->start);
840
841         ret = i2c_add_adapter(&i2c->adap);
842         if (ret < 0) {
843                 dev_err(&pdev->dev, "failed to add bus to i2c core\n");
844                 goto out;
845         }
846
847         platform_set_drvdata(pdev, i2c);
848
849         dev_info(&pdev->dev, "%s: S3C I2C adapter\n", i2c->adap.dev.bus_id);
850
851  out:
852         if (ret < 0)
853                 s3c24xx_i2c_free(i2c);
854
855         return ret;
856 }
857
858 /* s3c24xx_i2c_remove
859  *
860  * called when device is removed from the bus
861 */
862
863 static int s3c24xx_i2c_remove(struct platform_device *pdev)
864 {
865         struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
866         
867         if (i2c != NULL) {
868                 s3c24xx_i2c_free(i2c);
869                 platform_set_drvdata(pdev, NULL);
870         }
871
872         return 0;
873 }
874
875 #ifdef CONFIG_PM
876 static int s3c24xx_i2c_resume(struct platform_device *dev)
877 {
878         struct s3c24xx_i2c *i2c = platform_get_drvdata(dev);
879
880         if (i2c != NULL)
881                 s3c24xx_i2c_init(i2c);
882
883         return 0;
884 }
885
886 #else
887 #define s3c24xx_i2c_resume NULL
888 #endif
889
890 /* device driver for platform bus bits */
891
892 static struct platform_driver s3c2410_i2c_driver = {
893         .probe          = s3c24xx_i2c_probe,
894         .remove         = s3c24xx_i2c_remove,
895         .resume         = s3c24xx_i2c_resume,
896         .driver         = {
897                 .owner  = THIS_MODULE,
898                 .name   = "s3c2410-i2c",
899         },
900 };
901
902 static struct platform_driver s3c2440_i2c_driver = {
903         .probe          = s3c24xx_i2c_probe,
904         .remove         = s3c24xx_i2c_remove,
905         .resume         = s3c24xx_i2c_resume,
906         .driver         = {
907                 .owner  = THIS_MODULE,
908                 .name   = "s3c2440-i2c",
909         },
910 };
911
912 static int __init i2c_adap_s3c_init(void)
913 {
914         int ret;
915
916         ret = platform_driver_register(&s3c2410_i2c_driver);
917         if (ret == 0) {
918                 ret = platform_driver_register(&s3c2440_i2c_driver);
919                 if (ret)
920                         platform_driver_unregister(&s3c2410_i2c_driver);
921         }
922
923         return ret;
924 }
925
926 static void __exit i2c_adap_s3c_exit(void)
927 {
928         platform_driver_unregister(&s3c2410_i2c_driver);
929         platform_driver_unregister(&s3c2440_i2c_driver);
930 }
931
932 module_init(i2c_adap_s3c_init);
933 module_exit(i2c_adap_s3c_exit);
934
935 MODULE_DESCRIPTION("S3C24XX I2C Bus driver");
936 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
937 MODULE_LICENSE("GPL");