xref: /linux/arch/powerpc/platforms/powermac/low_i2c.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
1 /*
2  * arch/powerpc/platforms/powermac/low_i2c.c
3  *
4  *  Copyright (C) 2003-2005 Ben. Herrenschmidt (benh@kernel.crashing.org)
5  *
6  *  This program is free software; you can redistribute it and/or
7  *  modify it under the terms of the GNU General Public License
8  *  as published by the Free Software Foundation; either version
9  *  2 of the License, or (at your option) any later version.
10  *
11  * The linux i2c layer isn't completely suitable for our needs for various
12  * reasons ranging from too late initialisation to semantics not perfectly
13  * matching some requirements of the apple platform functions etc...
14  *
15  * This file thus provides a simple low level unified i2c interface for
16  * powermac that covers the various types of i2c busses used in Apple machines.
17  * For now, keywest, PMU and SMU, though we could add Cuda, or other bit
18  * banging busses found on older chipstes in earlier machines if we ever need
19  * one of them.
20  *
21  * The drivers in this file are synchronous/blocking. In addition, the
22  * keywest one is fairly slow due to the use of msleep instead of interrupts
23  * as the interrupt is currently used by i2c-keywest. In the long run, we
24  * might want to get rid of those high-level interfaces to linux i2c layer
25  * either completely (converting all drivers) or replacing them all with a
26  * single stub driver on top of this one. Once done, the interrupt will be
27  * available for our use.
28  */
29 
30 #undef DEBUG
31 #undef DEBUG_LOW
32 
33 #include <linux/config.h>
34 #include <linux/types.h>
35 #include <linux/sched.h>
36 #include <linux/init.h>
37 #include <linux/module.h>
38 #include <linux/adb.h>
39 #include <linux/pmu.h>
40 #include <linux/delay.h>
41 #include <linux/completion.h>
42 #include <linux/platform_device.h>
43 #include <linux/interrupt.h>
44 #include <linux/completion.h>
45 #include <linux/timer.h>
46 #include <asm/keylargo.h>
47 #include <asm/uninorth.h>
48 #include <asm/io.h>
49 #include <asm/prom.h>
50 #include <asm/machdep.h>
51 #include <asm/smu.h>
52 #include <asm/pmac_pfunc.h>
53 #include <asm/pmac_low_i2c.h>
54 
55 #ifdef DEBUG
56 #define DBG(x...) do {\
57 		printk(KERN_DEBUG "low_i2c:" x);	\
58 	} while(0)
59 #else
60 #define DBG(x...)
61 #endif
62 
63 #ifdef DEBUG_LOW
64 #define DBG_LOW(x...) do {\
65 		printk(KERN_DEBUG "low_i2c:" x);	\
66 	} while(0)
67 #else
68 #define DBG_LOW(x...)
69 #endif
70 
71 
72 static int pmac_i2c_force_poll = 1;
73 
74 /*
75  * A bus structure. Each bus in the system has such a structure associated.
76  */
77 struct pmac_i2c_bus
78 {
79 	struct list_head	link;
80 	struct device_node	*controller;
81 	struct device_node	*busnode;
82 	int			type;
83 	int			flags;
84 	struct i2c_adapter	*adapter;
85 	void			*hostdata;
86 	int			channel;	/* some hosts have multiple */
87 	int			mode;		/* current mode */
88 	struct semaphore	sem;
89 	int			opened;
90 	int			polled;		/* open mode */
91 	struct platform_device	*platform_dev;
92 
93 	/* ops */
94 	int (*open)(struct pmac_i2c_bus *bus);
95 	void (*close)(struct pmac_i2c_bus *bus);
96 	int (*xfer)(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
97 		    u32 subaddr, u8 *data, int len);
98 };
99 
100 static LIST_HEAD(pmac_i2c_busses);
101 
102 /*
103  * Keywest implementation
104  */
105 
106 struct pmac_i2c_host_kw
107 {
108 	struct semaphore	mutex;		/* Access mutex for use by
109 						 * i2c-keywest */
110 	void __iomem		*base;		/* register base address */
111 	int			bsteps;		/* register stepping */
112 	int			speed;		/* speed */
113 	int			irq;
114 	u8			*data;
115 	unsigned		len;
116 	int			state;
117 	int			rw;
118 	int			polled;
119 	int			result;
120 	struct completion	complete;
121 	spinlock_t		lock;
122 	struct timer_list	timeout_timer;
123 };
124 
125 /* Register indices */
126 typedef enum {
127 	reg_mode = 0,
128 	reg_control,
129 	reg_status,
130 	reg_isr,
131 	reg_ier,
132 	reg_addr,
133 	reg_subaddr,
134 	reg_data
135 } reg_t;
136 
137 /* The Tumbler audio equalizer can be really slow sometimes */
138 #define KW_POLL_TIMEOUT		(2*HZ)
139 
140 /* Mode register */
141 #define KW_I2C_MODE_100KHZ	0x00
142 #define KW_I2C_MODE_50KHZ	0x01
143 #define KW_I2C_MODE_25KHZ	0x02
144 #define KW_I2C_MODE_DUMB	0x00
145 #define KW_I2C_MODE_STANDARD	0x04
146 #define KW_I2C_MODE_STANDARDSUB	0x08
147 #define KW_I2C_MODE_COMBINED	0x0C
148 #define KW_I2C_MODE_MODE_MASK	0x0C
149 #define KW_I2C_MODE_CHAN_MASK	0xF0
150 
151 /* Control register */
152 #define KW_I2C_CTL_AAK		0x01
153 #define KW_I2C_CTL_XADDR	0x02
154 #define KW_I2C_CTL_STOP		0x04
155 #define KW_I2C_CTL_START	0x08
156 
157 /* Status register */
158 #define KW_I2C_STAT_BUSY	0x01
159 #define KW_I2C_STAT_LAST_AAK	0x02
160 #define KW_I2C_STAT_LAST_RW	0x04
161 #define KW_I2C_STAT_SDA		0x08
162 #define KW_I2C_STAT_SCL		0x10
163 
164 /* IER & ISR registers */
165 #define KW_I2C_IRQ_DATA		0x01
166 #define KW_I2C_IRQ_ADDR		0x02
167 #define KW_I2C_IRQ_STOP		0x04
168 #define KW_I2C_IRQ_START	0x08
169 #define KW_I2C_IRQ_MASK		0x0F
170 
171 /* State machine states */
172 enum {
173 	state_idle,
174 	state_addr,
175 	state_read,
176 	state_write,
177 	state_stop,
178 	state_dead
179 };
180 
181 #define WRONG_STATE(name) do {\
182 		printk(KERN_DEBUG "KW: wrong state. Got %s, state: %s " \
183 		       "(isr: %02x)\n",	\
184 		       name, __kw_state_names[host->state], isr); \
185 	} while(0)
186 
187 static const char *__kw_state_names[] = {
188 	"state_idle",
189 	"state_addr",
190 	"state_read",
191 	"state_write",
192 	"state_stop",
193 	"state_dead"
194 };
195 
196 static inline u8 __kw_read_reg(struct pmac_i2c_host_kw *host, reg_t reg)
197 {
198 	return readb(host->base + (((unsigned int)reg) << host->bsteps));
199 }
200 
201 static inline void __kw_write_reg(struct pmac_i2c_host_kw *host,
202 				  reg_t reg, u8 val)
203 {
204 	writeb(val, host->base + (((unsigned)reg) << host->bsteps));
205 	(void)__kw_read_reg(host, reg_subaddr);
206 }
207 
208 #define kw_write_reg(reg, val)	__kw_write_reg(host, reg, val)
209 #define kw_read_reg(reg)	__kw_read_reg(host, reg)
210 
211 static u8 kw_i2c_wait_interrupt(struct pmac_i2c_host_kw *host)
212 {
213 	int i, j;
214 	u8 isr;
215 
216 	for (i = 0; i < 1000; i++) {
217 		isr = kw_read_reg(reg_isr) & KW_I2C_IRQ_MASK;
218 		if (isr != 0)
219 			return isr;
220 
221 		/* This code is used with the timebase frozen, we cannot rely
222 		 * on udelay nor schedule when in polled mode !
223 		 * For now, just use a bogus loop....
224 		 */
225 		if (host->polled) {
226 			for (j = 1; j < 100000; j++)
227 				mb();
228 		} else
229 			msleep(1);
230 	}
231 	return isr;
232 }
233 
234 static void kw_i2c_handle_interrupt(struct pmac_i2c_host_kw *host, u8 isr)
235 {
236 	u8 ack;
237 
238 	DBG_LOW("kw_handle_interrupt(%s, isr: %x)\n",
239 		__kw_state_names[host->state], isr);
240 
241 	if (host->state == state_idle) {
242 		printk(KERN_WARNING "low_i2c: Keywest got an out of state"
243 		       " interrupt, ignoring\n");
244 		kw_write_reg(reg_isr, isr);
245 		return;
246 	}
247 
248 	if (isr == 0) {
249 		if (host->state != state_stop) {
250 			DBG_LOW("KW: Timeout !\n");
251 			host->result = -EIO;
252 			goto stop;
253 		}
254 		if (host->state == state_stop) {
255 			ack = kw_read_reg(reg_status);
256 			if (ack & KW_I2C_STAT_BUSY)
257 				kw_write_reg(reg_status, 0);
258 			host->state = state_idle;
259 			kw_write_reg(reg_ier, 0x00);
260 			if (!host->polled)
261 				complete(&host->complete);
262 		}
263 		return;
264 	}
265 
266 	if (isr & KW_I2C_IRQ_ADDR) {
267 		ack = kw_read_reg(reg_status);
268 		if (host->state != state_addr) {
269 			kw_write_reg(reg_isr, KW_I2C_IRQ_ADDR);
270 			WRONG_STATE("KW_I2C_IRQ_ADDR");
271 			host->result = -EIO;
272 			goto stop;
273 		}
274 		if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
275 			host->result = -ENODEV;
276 			DBG_LOW("KW: NAK on address\n");
277 			host->state = state_stop;
278 			return;
279 		} else {
280 			if (host->len == 0) {
281 				kw_write_reg(reg_isr, KW_I2C_IRQ_ADDR);
282 				goto stop;
283 			}
284 			if (host->rw) {
285 				host->state = state_read;
286 				if (host->len > 1)
287 					kw_write_reg(reg_control,
288 						     KW_I2C_CTL_AAK);
289 			} else {
290 				host->state = state_write;
291 				kw_write_reg(reg_data, *(host->data++));
292 				host->len--;
293 			}
294 		}
295 		kw_write_reg(reg_isr, KW_I2C_IRQ_ADDR);
296 	}
297 
298 	if (isr & KW_I2C_IRQ_DATA) {
299 		if (host->state == state_read) {
300 			*(host->data++) = kw_read_reg(reg_data);
301 			host->len--;
302 			kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
303 			if (host->len == 0)
304 				host->state = state_stop;
305 			else if (host->len == 1)
306 				kw_write_reg(reg_control, 0);
307 		} else if (host->state == state_write) {
308 			ack = kw_read_reg(reg_status);
309 			if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
310 				DBG_LOW("KW: nack on data write\n");
311 				host->result = -EIO;
312 				goto stop;
313 			} else if (host->len) {
314 				kw_write_reg(reg_data, *(host->data++));
315 				host->len--;
316 			} else {
317 				kw_write_reg(reg_control, KW_I2C_CTL_STOP);
318 				host->state = state_stop;
319 				host->result = 0;
320 			}
321 			kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
322 		} else {
323 			kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
324 			WRONG_STATE("KW_I2C_IRQ_DATA");
325 			if (host->state != state_stop) {
326 				host->result = -EIO;
327 				goto stop;
328 			}
329 		}
330 	}
331 
332 	if (isr & KW_I2C_IRQ_STOP) {
333 		kw_write_reg(reg_isr, KW_I2C_IRQ_STOP);
334 		if (host->state != state_stop) {
335 			WRONG_STATE("KW_I2C_IRQ_STOP");
336 			host->result = -EIO;
337 		}
338 		host->state = state_idle;
339 		if (!host->polled)
340 			complete(&host->complete);
341 	}
342 
343 	if (isr & KW_I2C_IRQ_START)
344 		kw_write_reg(reg_isr, KW_I2C_IRQ_START);
345 
346 	return;
347  stop:
348 	kw_write_reg(reg_control, KW_I2C_CTL_STOP);
349 	host->state = state_stop;
350 	return;
351 }
352 
353 /* Interrupt handler */
354 static irqreturn_t kw_i2c_irq(int irq, void *dev_id, struct pt_regs *regs)
355 {
356 	struct pmac_i2c_host_kw *host = dev_id;
357 	unsigned long flags;
358 
359 	spin_lock_irqsave(&host->lock, flags);
360 	del_timer(&host->timeout_timer);
361 	kw_i2c_handle_interrupt(host, kw_read_reg(reg_isr));
362 	if (host->state != state_idle) {
363 		host->timeout_timer.expires = jiffies + KW_POLL_TIMEOUT;
364 		add_timer(&host->timeout_timer);
365 	}
366 	spin_unlock_irqrestore(&host->lock, flags);
367 	return IRQ_HANDLED;
368 }
369 
370 static void kw_i2c_timeout(unsigned long data)
371 {
372 	struct pmac_i2c_host_kw *host = (struct pmac_i2c_host_kw *)data;
373 	unsigned long flags;
374 
375 	spin_lock_irqsave(&host->lock, flags);
376 	kw_i2c_handle_interrupt(host, kw_read_reg(reg_isr));
377 	if (host->state != state_idle) {
378 		host->timeout_timer.expires = jiffies + KW_POLL_TIMEOUT;
379 		add_timer(&host->timeout_timer);
380 	}
381 	spin_unlock_irqrestore(&host->lock, flags);
382 }
383 
384 static int kw_i2c_open(struct pmac_i2c_bus *bus)
385 {
386 	struct pmac_i2c_host_kw *host = bus->hostdata;
387 	down(&host->mutex);
388 	return 0;
389 }
390 
391 static void kw_i2c_close(struct pmac_i2c_bus *bus)
392 {
393 	struct pmac_i2c_host_kw *host = bus->hostdata;
394 	up(&host->mutex);
395 }
396 
397 static int kw_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
398 		       u32 subaddr, u8 *data, int len)
399 {
400 	struct pmac_i2c_host_kw *host = bus->hostdata;
401 	u8 mode_reg = host->speed;
402 	int use_irq = host->irq != NO_IRQ && !bus->polled;
403 
404 	/* Setup mode & subaddress if any */
405 	switch(bus->mode) {
406 	case pmac_i2c_mode_dumb:
407 		return -EINVAL;
408 	case pmac_i2c_mode_std:
409 		mode_reg |= KW_I2C_MODE_STANDARD;
410 		if (subsize != 0)
411 			return -EINVAL;
412 		break;
413 	case pmac_i2c_mode_stdsub:
414 		mode_reg |= KW_I2C_MODE_STANDARDSUB;
415 		if (subsize != 1)
416 			return -EINVAL;
417 		break;
418 	case pmac_i2c_mode_combined:
419 		mode_reg |= KW_I2C_MODE_COMBINED;
420 		if (subsize != 1)
421 			return -EINVAL;
422 		break;
423 	}
424 
425 	/* Setup channel & clear pending irqs */
426 	kw_write_reg(reg_isr, kw_read_reg(reg_isr));
427 	kw_write_reg(reg_mode, mode_reg | (bus->channel << 4));
428 	kw_write_reg(reg_status, 0);
429 
430 	/* Set up address and r/w bit, strip possible stale bus number from
431 	 * address top bits
432 	 */
433 	kw_write_reg(reg_addr, addrdir & 0xff);
434 
435 	/* Set up the sub address */
436 	if ((mode_reg & KW_I2C_MODE_MODE_MASK) == KW_I2C_MODE_STANDARDSUB
437 	    || (mode_reg & KW_I2C_MODE_MODE_MASK) == KW_I2C_MODE_COMBINED)
438 		kw_write_reg(reg_subaddr, subaddr);
439 
440 	/* Prepare for async operations */
441 	host->data = data;
442 	host->len = len;
443 	host->state = state_addr;
444 	host->result = 0;
445 	host->rw = (addrdir & 1);
446 	host->polled = bus->polled;
447 
448 	/* Enable interrupt if not using polled mode and interrupt is
449 	 * available
450 	 */
451 	if (use_irq) {
452 		/* Clear completion */
453 		INIT_COMPLETION(host->complete);
454 		/* Ack stale interrupts */
455 		kw_write_reg(reg_isr, kw_read_reg(reg_isr));
456 		/* Arm timeout */
457 		host->timeout_timer.expires = jiffies + KW_POLL_TIMEOUT;
458 		add_timer(&host->timeout_timer);
459 		/* Enable emission */
460 		kw_write_reg(reg_ier, KW_I2C_IRQ_MASK);
461 	}
462 
463 	/* Start sending address */
464 	kw_write_reg(reg_control, KW_I2C_CTL_XADDR);
465 
466 	/* Wait for completion */
467 	if (use_irq)
468 		wait_for_completion(&host->complete);
469 	else {
470 		while(host->state != state_idle) {
471 			unsigned long flags;
472 
473 			u8 isr = kw_i2c_wait_interrupt(host);
474 			spin_lock_irqsave(&host->lock, flags);
475 			kw_i2c_handle_interrupt(host, isr);
476 			spin_unlock_irqrestore(&host->lock, flags);
477 		}
478 	}
479 
480 	/* Disable emission */
481 	kw_write_reg(reg_ier, 0);
482 
483 	return host->result;
484 }
485 
486 static struct pmac_i2c_host_kw *__init kw_i2c_host_init(struct device_node *np)
487 {
488 	struct pmac_i2c_host_kw *host;
489 	u32			*psteps, *prate, *addrp, steps;
490 
491 	host = kzalloc(sizeof(struct pmac_i2c_host_kw), GFP_KERNEL);
492 	if (host == NULL) {
493 		printk(KERN_ERR "low_i2c: Can't allocate host for %s\n",
494 		       np->full_name);
495 		return NULL;
496 	}
497 
498 	/* Apple is kind enough to provide a valid AAPL,address property
499 	 * on all i2c keywest nodes so far ... we would have to fallback
500 	 * to macio parsing if that wasn't the case
501 	 */
502 	addrp = (u32 *)get_property(np, "AAPL,address", NULL);
503 	if (addrp == NULL) {
504 		printk(KERN_ERR "low_i2c: Can't find address for %s\n",
505 		       np->full_name);
506 		kfree(host);
507 		return NULL;
508 	}
509 	init_MUTEX(&host->mutex);
510 	init_completion(&host->complete);
511 	spin_lock_init(&host->lock);
512 	init_timer(&host->timeout_timer);
513 	host->timeout_timer.function = kw_i2c_timeout;
514 	host->timeout_timer.data = (unsigned long)host;
515 
516 	psteps = (u32 *)get_property(np, "AAPL,address-step", NULL);
517 	steps = psteps ? (*psteps) : 0x10;
518 	for (host->bsteps = 0; (steps & 0x01) == 0; host->bsteps++)
519 		steps >>= 1;
520 	/* Select interface rate */
521 	host->speed = KW_I2C_MODE_25KHZ;
522 	prate = (u32 *)get_property(np, "AAPL,i2c-rate", NULL);
523 	if (prate) switch(*prate) {
524 	case 100:
525 		host->speed = KW_I2C_MODE_100KHZ;
526 		break;
527 	case 50:
528 		host->speed = KW_I2C_MODE_50KHZ;
529 		break;
530 	case 25:
531 		host->speed = KW_I2C_MODE_25KHZ;
532 		break;
533 	}
534 	if (np->n_intrs > 0)
535 		host->irq = np->intrs[0].line;
536 	else
537 		host->irq = NO_IRQ;
538 
539 	host->base = ioremap((*addrp), 0x1000);
540 	if (host->base == NULL) {
541 		printk(KERN_ERR "low_i2c: Can't map registers for %s\n",
542 		       np->full_name);
543 		kfree(host);
544 		return NULL;
545 	}
546 
547 	/* Make sure IRA is disabled */
548 	kw_write_reg(reg_ier, 0);
549 
550 	/* Request chip interrupt */
551 	if (request_irq(host->irq, kw_i2c_irq, SA_SHIRQ, "keywest i2c", host))
552 		host->irq = NO_IRQ;
553 
554 	printk(KERN_INFO "KeyWest i2c @0x%08x irq %d %s\n",
555 	       *addrp, host->irq, np->full_name);
556 
557 	return host;
558 }
559 
560 
561 static void __init kw_i2c_add(struct pmac_i2c_host_kw *host,
562 			      struct device_node *controller,
563 			      struct device_node *busnode,
564 			      int channel)
565 {
566 	struct pmac_i2c_bus *bus;
567 
568 	bus = kzalloc(sizeof(struct pmac_i2c_bus), GFP_KERNEL);
569 	if (bus == NULL)
570 		return;
571 
572 	bus->controller = of_node_get(controller);
573 	bus->busnode = of_node_get(busnode);
574 	bus->type = pmac_i2c_bus_keywest;
575 	bus->hostdata = host;
576 	bus->channel = channel;
577 	bus->mode = pmac_i2c_mode_std;
578 	bus->open = kw_i2c_open;
579 	bus->close = kw_i2c_close;
580 	bus->xfer = kw_i2c_xfer;
581 	init_MUTEX(&bus->sem);
582 	if (controller == busnode)
583 		bus->flags = pmac_i2c_multibus;
584 	list_add(&bus->link, &pmac_i2c_busses);
585 
586 	printk(KERN_INFO " channel %d bus %s\n", channel,
587 	       (controller == busnode) ? "<multibus>" : busnode->full_name);
588 }
589 
590 static void __init kw_i2c_probe(void)
591 {
592 	struct device_node *np, *child, *parent;
593 
594 	/* Probe keywest-i2c busses */
595 	for (np = NULL;
596 	     (np = of_find_compatible_node(np, "i2c","keywest-i2c")) != NULL;){
597 		struct pmac_i2c_host_kw *host;
598 		int multibus, chans, i;
599 
600 		/* Found one, init a host structure */
601 		host = kw_i2c_host_init(np);
602 		if (host == NULL)
603 			continue;
604 
605 		/* Now check if we have a multibus setup (old style) or if we
606 		 * have proper bus nodes. Note that the "new" way (proper bus
607 		 * nodes) might cause us to not create some busses that are
608 		 * kept hidden in the device-tree. In the future, we might
609 		 * want to work around that by creating busses without a node
610 		 * but not for now
611 		 */
612 		child = of_get_next_child(np, NULL);
613 		multibus = !child || strcmp(child->name, "i2c-bus");
614 		of_node_put(child);
615 
616 		/* For a multibus setup, we get the bus count based on the
617 		 * parent type
618 		 */
619 		if (multibus) {
620 			parent = of_get_parent(np);
621 			if (parent == NULL)
622 				continue;
623 			chans = parent->name[0] == 'u' ? 2 : 1;
624 			for (i = 0; i < chans; i++)
625 				kw_i2c_add(host, np, np, i);
626 		} else {
627 			for (child = NULL;
628 			     (child = of_get_next_child(np, child)) != NULL;) {
629 				u32 *reg =
630 					(u32 *)get_property(child, "reg", NULL);
631 				if (reg == NULL)
632 					continue;
633 				kw_i2c_add(host, np, child, *reg);
634 			}
635 		}
636 	}
637 }
638 
639 
640 /*
641  *
642  * PMU implementation
643  *
644  */
645 
646 #ifdef CONFIG_ADB_PMU
647 
648 /*
649  * i2c command block to the PMU
650  */
651 struct pmu_i2c_hdr {
652 	u8	bus;
653 	u8	mode;
654 	u8	bus2;
655 	u8	address;
656 	u8	sub_addr;
657 	u8	comb_addr;
658 	u8	count;
659 	u8	data[];
660 };
661 
662 static void pmu_i2c_complete(struct adb_request *req)
663 {
664 	complete(req->arg);
665 }
666 
667 static int pmu_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
668 			u32 subaddr, u8 *data, int len)
669 {
670 	struct adb_request *req = bus->hostdata;
671 	struct pmu_i2c_hdr *hdr = (struct pmu_i2c_hdr *)&req->data[1];
672 	struct completion comp;
673 	int read = addrdir & 1;
674 	int retry;
675 	int rc = 0;
676 
677 	/* For now, limit ourselves to 16 bytes transfers */
678 	if (len > 16)
679 		return -EINVAL;
680 
681 	init_completion(&comp);
682 
683 	for (retry = 0; retry < 16; retry++) {
684 		memset(req, 0, sizeof(struct adb_request));
685 		hdr->bus = bus->channel;
686 		hdr->count = len;
687 
688 		switch(bus->mode) {
689 		case pmac_i2c_mode_std:
690 			if (subsize != 0)
691 				return -EINVAL;
692 			hdr->address = addrdir;
693 			hdr->mode = PMU_I2C_MODE_SIMPLE;
694 			break;
695 		case pmac_i2c_mode_stdsub:
696 		case pmac_i2c_mode_combined:
697 			if (subsize != 1)
698 				return -EINVAL;
699 			hdr->address = addrdir & 0xfe;
700 			hdr->comb_addr = addrdir;
701 			hdr->sub_addr = subaddr;
702 			if (bus->mode == pmac_i2c_mode_stdsub)
703 				hdr->mode = PMU_I2C_MODE_STDSUB;
704 			else
705 				hdr->mode = PMU_I2C_MODE_COMBINED;
706 			break;
707 		default:
708 			return -EINVAL;
709 		}
710 
711 		INIT_COMPLETION(comp);
712 		req->data[0] = PMU_I2C_CMD;
713 		req->reply[0] = 0xff;
714 		req->nbytes = sizeof(struct pmu_i2c_hdr) + 1;
715 		req->done = pmu_i2c_complete;
716 		req->arg = &comp;
717 		if (!read && len) {
718 			memcpy(hdr->data, data, len);
719 			req->nbytes += len;
720 		}
721 		rc = pmu_queue_request(req);
722 		if (rc)
723 			return rc;
724 		wait_for_completion(&comp);
725 		if (req->reply[0] == PMU_I2C_STATUS_OK)
726 			break;
727 		msleep(15);
728 	}
729 	if (req->reply[0] != PMU_I2C_STATUS_OK)
730 		return -EIO;
731 
732 	for (retry = 0; retry < 16; retry++) {
733 		memset(req, 0, sizeof(struct adb_request));
734 
735 		/* I know that looks like a lot, slow as hell, but darwin
736 		 * does it so let's be on the safe side for now
737 		 */
738 		msleep(15);
739 
740 		hdr->bus = PMU_I2C_BUS_STATUS;
741 
742 		INIT_COMPLETION(comp);
743 		req->data[0] = PMU_I2C_CMD;
744 		req->reply[0] = 0xff;
745 		req->nbytes = 2;
746 		req->done = pmu_i2c_complete;
747 		req->arg = &comp;
748 		rc = pmu_queue_request(req);
749 		if (rc)
750 			return rc;
751 		wait_for_completion(&comp);
752 
753 		if (req->reply[0] == PMU_I2C_STATUS_OK && !read)
754 			return 0;
755 		if (req->reply[0] == PMU_I2C_STATUS_DATAREAD && read) {
756 			int rlen = req->reply_len - 1;
757 
758 			if (rlen != len) {
759 				printk(KERN_WARNING "low_i2c: PMU returned %d"
760 				       " bytes, expected %d !\n", rlen, len);
761 				return -EIO;
762 			}
763 			if (len)
764 				memcpy(data, &req->reply[1], len);
765 			return 0;
766 		}
767 	}
768 	return -EIO;
769 }
770 
771 static void __init pmu_i2c_probe(void)
772 {
773 	struct pmac_i2c_bus *bus;
774 	struct device_node *busnode;
775 	int channel, sz;
776 
777 	if (!pmu_present())
778 		return;
779 
780 	/* There might or might not be a "pmu-i2c" node, we use that
781 	 * or via-pmu itself, whatever we find. I haven't seen a machine
782 	 * with separate bus nodes, so we assume a multibus setup
783 	 */
784 	busnode = of_find_node_by_name(NULL, "pmu-i2c");
785 	if (busnode == NULL)
786 		busnode = of_find_node_by_name(NULL, "via-pmu");
787 	if (busnode == NULL)
788 		return;
789 
790 	printk(KERN_INFO "PMU i2c %s\n", busnode->full_name);
791 
792 	/*
793 	 * We add bus 1 and 2 only for now, bus 0 is "special"
794 	 */
795 	for (channel = 1; channel <= 2; channel++) {
796 		sz = sizeof(struct pmac_i2c_bus) + sizeof(struct adb_request);
797 		bus = kzalloc(sz, GFP_KERNEL);
798 		if (bus == NULL)
799 			return;
800 
801 		bus->controller = busnode;
802 		bus->busnode = busnode;
803 		bus->type = pmac_i2c_bus_pmu;
804 		bus->channel = channel;
805 		bus->mode = pmac_i2c_mode_std;
806 		bus->hostdata = bus + 1;
807 		bus->xfer = pmu_i2c_xfer;
808 		init_MUTEX(&bus->sem);
809 		bus->flags = pmac_i2c_multibus;
810 		list_add(&bus->link, &pmac_i2c_busses);
811 
812 		printk(KERN_INFO " channel %d bus <multibus>\n", channel);
813 	}
814 }
815 
816 #endif /* CONFIG_ADB_PMU */
817 
818 
819 /*
820  *
821  * SMU implementation
822  *
823  */
824 
825 #ifdef CONFIG_PMAC_SMU
826 
827 static void smu_i2c_complete(struct smu_i2c_cmd *cmd, void *misc)
828 {
829 	complete(misc);
830 }
831 
832 static int smu_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
833 			u32 subaddr, u8 *data, int len)
834 {
835 	struct smu_i2c_cmd *cmd = bus->hostdata;
836 	struct completion comp;
837 	int read = addrdir & 1;
838 	int rc = 0;
839 
840 	if ((read && len > SMU_I2C_READ_MAX) ||
841 	    ((!read) && len > SMU_I2C_WRITE_MAX))
842 		return -EINVAL;
843 
844 	memset(cmd, 0, sizeof(struct smu_i2c_cmd));
845 	cmd->info.bus = bus->channel;
846 	cmd->info.devaddr = addrdir;
847 	cmd->info.datalen = len;
848 
849 	switch(bus->mode) {
850 	case pmac_i2c_mode_std:
851 		if (subsize != 0)
852 			return -EINVAL;
853 		cmd->info.type = SMU_I2C_TRANSFER_SIMPLE;
854 		break;
855 	case pmac_i2c_mode_stdsub:
856 	case pmac_i2c_mode_combined:
857 		if (subsize > 3 || subsize < 1)
858 			return -EINVAL;
859 		cmd->info.sublen = subsize;
860 		/* that's big-endian only but heh ! */
861 		memcpy(&cmd->info.subaddr, ((char *)&subaddr) + (4 - subsize),
862 		       subsize);
863 		if (bus->mode == pmac_i2c_mode_stdsub)
864 			cmd->info.type = SMU_I2C_TRANSFER_STDSUB;
865 		else
866 			cmd->info.type = SMU_I2C_TRANSFER_COMBINED;
867 		break;
868 	default:
869 		return -EINVAL;
870 	}
871 	if (!read && len)
872 		memcpy(cmd->info.data, data, len);
873 
874 	init_completion(&comp);
875 	cmd->done = smu_i2c_complete;
876 	cmd->misc = &comp;
877 	rc = smu_queue_i2c(cmd);
878 	if (rc < 0)
879 		return rc;
880 	wait_for_completion(&comp);
881 	rc = cmd->status;
882 
883 	if (read && len)
884 		memcpy(data, cmd->info.data, len);
885 	return rc < 0 ? rc : 0;
886 }
887 
888 static void __init smu_i2c_probe(void)
889 {
890 	struct device_node *controller, *busnode;
891 	struct pmac_i2c_bus *bus;
892 	u32 *reg;
893 	int sz;
894 
895 	if (!smu_present())
896 		return;
897 
898 	controller = of_find_node_by_name(NULL, "smu-i2c-control");
899 	if (controller == NULL)
900 		controller = of_find_node_by_name(NULL, "smu");
901 	if (controller == NULL)
902 		return;
903 
904 	printk(KERN_INFO "SMU i2c %s\n", controller->full_name);
905 
906 	/* Look for childs, note that they might not be of the right
907 	 * type as older device trees mix i2c busses and other thigns
908 	 * at the same level
909 	 */
910 	for (busnode = NULL;
911 	     (busnode = of_get_next_child(controller, busnode)) != NULL;) {
912 		if (strcmp(busnode->type, "i2c") &&
913 		    strcmp(busnode->type, "i2c-bus"))
914 			continue;
915 		reg = (u32 *)get_property(busnode, "reg", NULL);
916 		if (reg == NULL)
917 			continue;
918 
919 		sz = sizeof(struct pmac_i2c_bus) + sizeof(struct smu_i2c_cmd);
920 		bus = kzalloc(sz, GFP_KERNEL);
921 		if (bus == NULL)
922 			return;
923 
924 		bus->controller = controller;
925 		bus->busnode = of_node_get(busnode);
926 		bus->type = pmac_i2c_bus_smu;
927 		bus->channel = *reg;
928 		bus->mode = pmac_i2c_mode_std;
929 		bus->hostdata = bus + 1;
930 		bus->xfer = smu_i2c_xfer;
931 		init_MUTEX(&bus->sem);
932 		bus->flags = 0;
933 		list_add(&bus->link, &pmac_i2c_busses);
934 
935 		printk(KERN_INFO " channel %x bus %s\n",
936 		       bus->channel, busnode->full_name);
937 	}
938 }
939 
940 #endif /* CONFIG_PMAC_SMU */
941 
942 /*
943  *
944  * Core code
945  *
946  */
947 
948 
949 struct pmac_i2c_bus *pmac_i2c_find_bus(struct device_node *node)
950 {
951 	struct device_node *p = of_node_get(node);
952 	struct device_node *prev = NULL;
953 	struct pmac_i2c_bus *bus;
954 
955 	while(p) {
956 		list_for_each_entry(bus, &pmac_i2c_busses, link) {
957 			if (p == bus->busnode) {
958 				if (prev && bus->flags & pmac_i2c_multibus) {
959 					u32 *reg;
960 					reg = (u32 *)get_property(prev, "reg",
961 								  NULL);
962 					if (!reg)
963 						continue;
964 					if (((*reg) >> 8) != bus->channel)
965 						continue;
966 				}
967 				of_node_put(p);
968 				of_node_put(prev);
969 				return bus;
970 			}
971 		}
972 		of_node_put(prev);
973 		prev = p;
974 		p = of_get_parent(p);
975 	}
976 	return NULL;
977 }
978 EXPORT_SYMBOL_GPL(pmac_i2c_find_bus);
979 
980 u8 pmac_i2c_get_dev_addr(struct device_node *device)
981 {
982 	u32 *reg = (u32 *)get_property(device, "reg", NULL);
983 
984 	if (reg == NULL)
985 		return 0;
986 
987 	return (*reg) & 0xff;
988 }
989 EXPORT_SYMBOL_GPL(pmac_i2c_get_dev_addr);
990 
991 struct device_node *pmac_i2c_get_controller(struct pmac_i2c_bus *bus)
992 {
993 	return bus->controller;
994 }
995 EXPORT_SYMBOL_GPL(pmac_i2c_get_controller);
996 
997 struct device_node *pmac_i2c_get_bus_node(struct pmac_i2c_bus *bus)
998 {
999 	return bus->busnode;
1000 }
1001 EXPORT_SYMBOL_GPL(pmac_i2c_get_bus_node);
1002 
1003 int pmac_i2c_get_type(struct pmac_i2c_bus *bus)
1004 {
1005 	return bus->type;
1006 }
1007 EXPORT_SYMBOL_GPL(pmac_i2c_get_type);
1008 
1009 int pmac_i2c_get_flags(struct pmac_i2c_bus *bus)
1010 {
1011 	return bus->flags;
1012 }
1013 EXPORT_SYMBOL_GPL(pmac_i2c_get_flags);
1014 
1015 int pmac_i2c_get_channel(struct pmac_i2c_bus *bus)
1016 {
1017 	return bus->channel;
1018 }
1019 EXPORT_SYMBOL_GPL(pmac_i2c_get_channel);
1020 
1021 
1022 void pmac_i2c_attach_adapter(struct pmac_i2c_bus *bus,
1023 			     struct i2c_adapter *adapter)
1024 {
1025 	WARN_ON(bus->adapter != NULL);
1026 	bus->adapter = adapter;
1027 }
1028 EXPORT_SYMBOL_GPL(pmac_i2c_attach_adapter);
1029 
1030 void pmac_i2c_detach_adapter(struct pmac_i2c_bus *bus,
1031 			     struct i2c_adapter *adapter)
1032 {
1033 	WARN_ON(bus->adapter != adapter);
1034 	bus->adapter = NULL;
1035 }
1036 EXPORT_SYMBOL_GPL(pmac_i2c_detach_adapter);
1037 
1038 struct i2c_adapter *pmac_i2c_get_adapter(struct pmac_i2c_bus *bus)
1039 {
1040 	return bus->adapter;
1041 }
1042 EXPORT_SYMBOL_GPL(pmac_i2c_get_adapter);
1043 
1044 struct pmac_i2c_bus *pmac_i2c_adapter_to_bus(struct i2c_adapter *adapter)
1045 {
1046 	struct pmac_i2c_bus *bus;
1047 
1048 	list_for_each_entry(bus, &pmac_i2c_busses, link)
1049 		if (bus->adapter == adapter)
1050 			return bus;
1051 	return NULL;
1052 }
1053 EXPORT_SYMBOL_GPL(pmac_i2c_adapter_to_bus);
1054 
1055 int pmac_i2c_match_adapter(struct device_node *dev, struct i2c_adapter *adapter)
1056 {
1057 	struct pmac_i2c_bus *bus = pmac_i2c_find_bus(dev);
1058 
1059 	if (bus == NULL)
1060 		return 0;
1061 	return (bus->adapter == adapter);
1062 }
1063 EXPORT_SYMBOL_GPL(pmac_i2c_match_adapter);
1064 
1065 int pmac_low_i2c_lock(struct device_node *np)
1066 {
1067 	struct pmac_i2c_bus *bus, *found = NULL;
1068 
1069 	list_for_each_entry(bus, &pmac_i2c_busses, link) {
1070 		if (np == bus->controller) {
1071 			found = bus;
1072 			break;
1073 		}
1074 	}
1075 	if (!found)
1076 		return -ENODEV;
1077 	return pmac_i2c_open(bus, 0);
1078 }
1079 EXPORT_SYMBOL_GPL(pmac_low_i2c_lock);
1080 
1081 int pmac_low_i2c_unlock(struct device_node *np)
1082 {
1083 	struct pmac_i2c_bus *bus, *found = NULL;
1084 
1085 	list_for_each_entry(bus, &pmac_i2c_busses, link) {
1086 		if (np == bus->controller) {
1087 			found = bus;
1088 			break;
1089 		}
1090 	}
1091 	if (!found)
1092 		return -ENODEV;
1093 	pmac_i2c_close(bus);
1094 	return 0;
1095 }
1096 EXPORT_SYMBOL_GPL(pmac_low_i2c_unlock);
1097 
1098 
1099 int pmac_i2c_open(struct pmac_i2c_bus *bus, int polled)
1100 {
1101 	int rc;
1102 
1103 	down(&bus->sem);
1104 	bus->polled = polled || pmac_i2c_force_poll;
1105 	bus->opened = 1;
1106 	bus->mode = pmac_i2c_mode_std;
1107 	if (bus->open && (rc = bus->open(bus)) != 0) {
1108 		bus->opened = 0;
1109 		up(&bus->sem);
1110 		return rc;
1111 	}
1112 	return 0;
1113 }
1114 EXPORT_SYMBOL_GPL(pmac_i2c_open);
1115 
1116 void pmac_i2c_close(struct pmac_i2c_bus *bus)
1117 {
1118 	WARN_ON(!bus->opened);
1119 	if (bus->close)
1120 		bus->close(bus);
1121 	bus->opened = 0;
1122 	up(&bus->sem);
1123 }
1124 EXPORT_SYMBOL_GPL(pmac_i2c_close);
1125 
1126 int pmac_i2c_setmode(struct pmac_i2c_bus *bus, int mode)
1127 {
1128 	WARN_ON(!bus->opened);
1129 
1130 	/* Report me if you see the error below as there might be a new
1131 	 * "combined4" mode that I need to implement for the SMU bus
1132 	 */
1133 	if (mode < pmac_i2c_mode_dumb || mode > pmac_i2c_mode_combined) {
1134 		printk(KERN_ERR "low_i2c: Invalid mode %d requested on"
1135 		       " bus %s !\n", mode, bus->busnode->full_name);
1136 		return -EINVAL;
1137 	}
1138 	bus->mode = mode;
1139 
1140 	return 0;
1141 }
1142 EXPORT_SYMBOL_GPL(pmac_i2c_setmode);
1143 
1144 int pmac_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
1145 		  u32 subaddr, u8 *data, int len)
1146 {
1147 	int rc;
1148 
1149 	WARN_ON(!bus->opened);
1150 
1151 	DBG("xfer() chan=%d, addrdir=0x%x, mode=%d, subsize=%d, subaddr=0x%x,"
1152 	    " %d bytes, bus %s\n", bus->channel, addrdir, bus->mode, subsize,
1153 	    subaddr, len, bus->busnode->full_name);
1154 
1155 	rc = bus->xfer(bus, addrdir, subsize, subaddr, data, len);
1156 
1157 #ifdef DEBUG
1158 	if (rc)
1159 		DBG("xfer error %d\n", rc);
1160 #endif
1161 	return rc;
1162 }
1163 EXPORT_SYMBOL_GPL(pmac_i2c_xfer);
1164 
1165 /* some quirks for platform function decoding */
1166 enum {
1167 	pmac_i2c_quirk_invmask = 0x00000001u,
1168 };
1169 
1170 static void pmac_i2c_devscan(void (*callback)(struct device_node *dev,
1171 					      int quirks))
1172 {
1173 	struct pmac_i2c_bus *bus;
1174 	struct device_node *np;
1175 	static struct whitelist_ent {
1176 		char *name;
1177 		char *compatible;
1178 		int quirks;
1179 	} whitelist[] = {
1180 		/* XXX Study device-tree's & apple drivers are get the quirks
1181 		 * right !
1182 		 */
1183 		{ "i2c-hwclock", NULL, pmac_i2c_quirk_invmask },
1184 		{ "i2c-cpu-voltage", NULL, 0},
1185 		{  "temp-monitor", NULL, 0 },
1186 		{  "supply-monitor", NULL, 0 },
1187 		{ NULL, NULL, 0 },
1188 	};
1189 
1190 	/* Only some devices need to have platform functions instanciated
1191 	 * here. For now, we have a table. Others, like 9554 i2c GPIOs used
1192 	 * on Xserve, if we ever do a driver for them, will use their own
1193 	 * platform function instance
1194 	 */
1195 	list_for_each_entry(bus, &pmac_i2c_busses, link) {
1196 		for (np = NULL;
1197 		     (np = of_get_next_child(bus->busnode, np)) != NULL;) {
1198 			struct whitelist_ent *p;
1199 			/* If multibus, check if device is on that bus */
1200 			if (bus->flags & pmac_i2c_multibus)
1201 				if (bus != pmac_i2c_find_bus(np))
1202 					continue;
1203 			for (p = whitelist; p->name != NULL; p++) {
1204 				if (strcmp(np->name, p->name))
1205 					continue;
1206 				if (p->compatible &&
1207 				    !device_is_compatible(np, p->compatible))
1208 					continue;
1209 				callback(np, p->quirks);
1210 				break;
1211 			}
1212 		}
1213 	}
1214 }
1215 
1216 #define MAX_I2C_DATA	64
1217 
1218 struct pmac_i2c_pf_inst
1219 {
1220 	struct pmac_i2c_bus	*bus;
1221 	u8			addr;
1222 	u8			buffer[MAX_I2C_DATA];
1223 	u8			scratch[MAX_I2C_DATA];
1224 	int			bytes;
1225 	int			quirks;
1226 };
1227 
1228 static void* pmac_i2c_do_begin(struct pmf_function *func, struct pmf_args *args)
1229 {
1230 	struct pmac_i2c_pf_inst *inst;
1231 	struct pmac_i2c_bus	*bus;
1232 
1233 	bus = pmac_i2c_find_bus(func->node);
1234 	if (bus == NULL) {
1235 		printk(KERN_ERR "low_i2c: Can't find bus for %s (pfunc)\n",
1236 		       func->node->full_name);
1237 		return NULL;
1238 	}
1239 	if (pmac_i2c_open(bus, 0)) {
1240 		printk(KERN_ERR "low_i2c: Can't open i2c bus for %s (pfunc)\n",
1241 		       func->node->full_name);
1242 		return NULL;
1243 	}
1244 
1245 	/* XXX might need GFP_ATOMIC when called during the suspend process,
1246 	 * but then, there are already lots of issues with suspending when
1247 	 * near OOM that need to be resolved, the allocator itself should
1248 	 * probably make GFP_NOIO implicit during suspend
1249 	 */
1250 	inst = kzalloc(sizeof(struct pmac_i2c_pf_inst), GFP_KERNEL);
1251 	if (inst == NULL) {
1252 		pmac_i2c_close(bus);
1253 		return NULL;
1254 	}
1255 	inst->bus = bus;
1256 	inst->addr = pmac_i2c_get_dev_addr(func->node);
1257 	inst->quirks = (int)(long)func->driver_data;
1258 	return inst;
1259 }
1260 
1261 static void pmac_i2c_do_end(struct pmf_function *func, void *instdata)
1262 {
1263 	struct pmac_i2c_pf_inst *inst = instdata;
1264 
1265 	if (inst == NULL)
1266 		return;
1267 	pmac_i2c_close(inst->bus);
1268 	if (inst)
1269 		kfree(inst);
1270 }
1271 
1272 static int pmac_i2c_do_read(PMF_STD_ARGS, u32 len)
1273 {
1274 	struct pmac_i2c_pf_inst *inst = instdata;
1275 
1276 	inst->bytes = len;
1277 	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_read, 0, 0,
1278 			     inst->buffer, len);
1279 }
1280 
1281 static int pmac_i2c_do_write(PMF_STD_ARGS, u32 len, const u8 *data)
1282 {
1283 	struct pmac_i2c_pf_inst *inst = instdata;
1284 
1285 	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 0, 0,
1286 			     (u8 *)data, len);
1287 }
1288 
1289 /* This function is used to do the masking & OR'ing for the "rmw" type
1290  * callbacks. Ze should apply the mask and OR in the values in the
1291  * buffer before writing back. The problem is that it seems that
1292  * various darwin drivers implement the mask/or differently, thus
1293  * we need to check the quirks first
1294  */
1295 static void pmac_i2c_do_apply_rmw(struct pmac_i2c_pf_inst *inst,
1296 				  u32 len, const u8 *mask, const u8 *val)
1297 {
1298 	int i;
1299 
1300 	if (inst->quirks & pmac_i2c_quirk_invmask) {
1301 		for (i = 0; i < len; i ++)
1302 			inst->scratch[i] = (inst->buffer[i] & mask[i]) | val[i];
1303 	} else {
1304 		for (i = 0; i < len; i ++)
1305 			inst->scratch[i] = (inst->buffer[i] & ~mask[i])
1306 				| (val[i] & mask[i]);
1307 	}
1308 }
1309 
1310 static int pmac_i2c_do_rmw(PMF_STD_ARGS, u32 masklen, u32 valuelen,
1311 			   u32 totallen, const u8 *maskdata,
1312 			   const u8 *valuedata)
1313 {
1314 	struct pmac_i2c_pf_inst *inst = instdata;
1315 
1316 	if (masklen > inst->bytes || valuelen > inst->bytes ||
1317 	    totallen > inst->bytes || valuelen > masklen)
1318 		return -EINVAL;
1319 
1320 	pmac_i2c_do_apply_rmw(inst, masklen, maskdata, valuedata);
1321 
1322 	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 0, 0,
1323 			     inst->scratch, totallen);
1324 }
1325 
1326 static int pmac_i2c_do_read_sub(PMF_STD_ARGS, u8 subaddr, u32 len)
1327 {
1328 	struct pmac_i2c_pf_inst *inst = instdata;
1329 
1330 	inst->bytes = len;
1331 	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_read, 1, subaddr,
1332 			     inst->buffer, len);
1333 }
1334 
1335 static int pmac_i2c_do_write_sub(PMF_STD_ARGS, u8 subaddr, u32 len,
1336 				     const u8 *data)
1337 {
1338 	struct pmac_i2c_pf_inst *inst = instdata;
1339 
1340 	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 1,
1341 			     subaddr, (u8 *)data, len);
1342 }
1343 
1344 static int pmac_i2c_do_set_mode(PMF_STD_ARGS, int mode)
1345 {
1346 	struct pmac_i2c_pf_inst *inst = instdata;
1347 
1348 	return pmac_i2c_setmode(inst->bus, mode);
1349 }
1350 
1351 static int pmac_i2c_do_rmw_sub(PMF_STD_ARGS, u8 subaddr, u32 masklen,
1352 			       u32 valuelen, u32 totallen, const u8 *maskdata,
1353 			       const u8 *valuedata)
1354 {
1355 	struct pmac_i2c_pf_inst *inst = instdata;
1356 
1357 	if (masklen > inst->bytes || valuelen > inst->bytes ||
1358 	    totallen > inst->bytes || valuelen > masklen)
1359 		return -EINVAL;
1360 
1361 	pmac_i2c_do_apply_rmw(inst, masklen, maskdata, valuedata);
1362 
1363 	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 1,
1364 			     subaddr, inst->scratch, totallen);
1365 }
1366 
1367 static int pmac_i2c_do_mask_and_comp(PMF_STD_ARGS, u32 len,
1368 				     const u8 *maskdata,
1369 				     const u8 *valuedata)
1370 {
1371 	struct pmac_i2c_pf_inst *inst = instdata;
1372 	int i, match;
1373 
1374 	/* Get return value pointer, it's assumed to be a u32 */
1375 	if (!args || !args->count || !args->u[0].p)
1376 		return -EINVAL;
1377 
1378 	/* Check buffer */
1379 	if (len > inst->bytes)
1380 		return -EINVAL;
1381 
1382 	for (i = 0, match = 1; match && i < len; i ++)
1383 		if ((inst->buffer[i] & maskdata[i]) != valuedata[i])
1384 			match = 0;
1385 	*args->u[0].p = match;
1386 	return 0;
1387 }
1388 
1389 static int pmac_i2c_do_delay(PMF_STD_ARGS, u32 duration)
1390 {
1391 	msleep((duration + 999) / 1000);
1392 	return 0;
1393 }
1394 
1395 
1396 static struct pmf_handlers pmac_i2c_pfunc_handlers = {
1397 	.begin			= pmac_i2c_do_begin,
1398 	.end			= pmac_i2c_do_end,
1399 	.read_i2c		= pmac_i2c_do_read,
1400 	.write_i2c		= pmac_i2c_do_write,
1401 	.rmw_i2c		= pmac_i2c_do_rmw,
1402 	.read_i2c_sub		= pmac_i2c_do_read_sub,
1403 	.write_i2c_sub		= pmac_i2c_do_write_sub,
1404 	.rmw_i2c_sub		= pmac_i2c_do_rmw_sub,
1405 	.set_i2c_mode		= pmac_i2c_do_set_mode,
1406 	.mask_and_compare	= pmac_i2c_do_mask_and_comp,
1407 	.delay			= pmac_i2c_do_delay,
1408 };
1409 
1410 static void __init pmac_i2c_dev_create(struct device_node *np, int quirks)
1411 {
1412 	DBG("dev_create(%s)\n", np->full_name);
1413 
1414 	pmf_register_driver(np, &pmac_i2c_pfunc_handlers,
1415 			    (void *)(long)quirks);
1416 }
1417 
1418 static void __init pmac_i2c_dev_init(struct device_node *np, int quirks)
1419 {
1420 	DBG("dev_create(%s)\n", np->full_name);
1421 
1422 	pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_INIT, NULL);
1423 }
1424 
1425 static void pmac_i2c_dev_suspend(struct device_node *np, int quirks)
1426 {
1427 	DBG("dev_suspend(%s)\n", np->full_name);
1428 	pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_SLEEP, NULL);
1429 }
1430 
1431 static void pmac_i2c_dev_resume(struct device_node *np, int quirks)
1432 {
1433 	DBG("dev_resume(%s)\n", np->full_name);
1434 	pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_WAKE, NULL);
1435 }
1436 
1437 void pmac_pfunc_i2c_suspend(void)
1438 {
1439 	pmac_i2c_devscan(pmac_i2c_dev_suspend);
1440 }
1441 
1442 void pmac_pfunc_i2c_resume(void)
1443 {
1444 	pmac_i2c_devscan(pmac_i2c_dev_resume);
1445 }
1446 
1447 /*
1448  * Initialize us: probe all i2c busses on the machine, instantiate
1449  * busses and platform functions as needed.
1450  */
1451 /* This is non-static as it might be called early by smp code */
1452 int __init pmac_i2c_init(void)
1453 {
1454 	static int i2c_inited;
1455 
1456 	if (i2c_inited)
1457 		return 0;
1458 	i2c_inited = 1;
1459 
1460 	if (!machine_is(powermac))
1461 		return 0;
1462 
1463 	/* Probe keywest-i2c busses */
1464 	kw_i2c_probe();
1465 
1466 #ifdef CONFIG_ADB_PMU
1467 	/* Probe PMU i2c busses */
1468 	pmu_i2c_probe();
1469 #endif
1470 
1471 #ifdef CONFIG_PMAC_SMU
1472 	/* Probe SMU i2c busses */
1473 	smu_i2c_probe();
1474 #endif
1475 
1476 	/* Now add plaform functions for some known devices */
1477 	pmac_i2c_devscan(pmac_i2c_dev_create);
1478 
1479 	return 0;
1480 }
1481 arch_initcall(pmac_i2c_init);
1482 
1483 /* Since pmac_i2c_init can be called too early for the platform device
1484  * registration, we need to do it at a later time. In our case, subsys
1485  * happens to fit well, though I agree it's a bit of a hack...
1486  */
1487 static int __init pmac_i2c_create_platform_devices(void)
1488 {
1489 	struct pmac_i2c_bus *bus;
1490 	int i = 0;
1491 
1492 	/* In the case where we are initialized from smp_init(), we must
1493 	 * not use the timer (and thus the irq). It's safe from now on
1494 	 * though
1495 	 */
1496 	pmac_i2c_force_poll = 0;
1497 
1498 	/* Create platform devices */
1499 	list_for_each_entry(bus, &pmac_i2c_busses, link) {
1500 		bus->platform_dev =
1501 			platform_device_alloc("i2c-powermac", i++);
1502 		if (bus->platform_dev == NULL)
1503 			return -ENOMEM;
1504 		bus->platform_dev->dev.platform_data = bus;
1505 		platform_device_add(bus->platform_dev);
1506 	}
1507 
1508 	/* Now call platform "init" functions */
1509 	pmac_i2c_devscan(pmac_i2c_dev_init);
1510 
1511 	return 0;
1512 }
1513 subsys_initcall(pmac_i2c_create_platform_devices);
1514