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TOMOYO Linux Cross Reference
Linux/arch/powerpc/platforms/powermac/low_i2c.c

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  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 chipsets 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/types.h>
 34 #include <linux/sched.h>
 35 #include <linux/init.h>
 36 #include <linux/export.h>
 37 #include <linux/adb.h>
 38 #include <linux/pmu.h>
 39 #include <linux/delay.h>
 40 #include <linux/completion.h>
 41 #include <linux/platform_device.h>
 42 #include <linux/interrupt.h>
 43 #include <linux/timer.h>
 44 #include <linux/mutex.h>
 45 #include <linux/i2c.h>
 46 #include <linux/slab.h>
 47 #include <asm/keylargo.h>
 48 #include <asm/uninorth.h>
 49 #include <asm/io.h>
 50 #include <asm/prom.h>
 51 #include <asm/machdep.h>
 52 #include <asm/smu.h>
 53 #include <asm/pmac_pfunc.h>
 54 #include <asm/pmac_low_i2c.h>
 55 
 56 #ifdef DEBUG
 57 #define DBG(x...) do {\
 58                 printk(KERN_DEBUG "low_i2c:" x);        \
 59         } while(0)
 60 #else
 61 #define DBG(x...)
 62 #endif
 63 
 64 #ifdef DEBUG_LOW
 65 #define DBG_LOW(x...) do {\
 66                 printk(KERN_DEBUG "low_i2c:" x);        \
 67         } while(0)
 68 #else
 69 #define DBG_LOW(x...)
 70 #endif
 71 
 72 
 73 static int pmac_i2c_force_poll = 1;
 74 
 75 /*
 76  * A bus structure. Each bus in the system has such a structure associated.
 77  */
 78 struct pmac_i2c_bus
 79 {
 80         struct list_head        link;
 81         struct device_node      *controller;
 82         struct device_node      *busnode;
 83         int                     type;
 84         int                     flags;
 85         struct i2c_adapter      adapter;
 86         void                    *hostdata;
 87         int                     channel;        /* some hosts have multiple */
 88         int                     mode;           /* current mode */
 89         struct mutex            mutex;
 90         int                     opened;
 91         int                     polled;         /* open mode */
 92         struct platform_device  *platform_dev;
 93         struct lock_class_key   lock_key;
 94 
 95         /* ops */
 96         int (*open)(struct pmac_i2c_bus *bus);
 97         void (*close)(struct pmac_i2c_bus *bus);
 98         int (*xfer)(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
 99                     u32 subaddr, u8 *data, int len);
100 };
101 
102 static LIST_HEAD(pmac_i2c_busses);
103 
104 /*
105  * Keywest implementation
106  */
107 
108 struct pmac_i2c_host_kw
109 {
110         struct mutex            mutex;          /* Access mutex for use by
111                                                  * i2c-keywest */
112         void __iomem            *base;          /* register base address */
113         int                     bsteps;         /* register stepping */
114         int                     speed;          /* speed */
115         int                     irq;
116         u8                      *data;
117         unsigned                len;
118         int                     state;
119         int                     rw;
120         int                     polled;
121         int                     result;
122         struct completion       complete;
123         spinlock_t              lock;
124         struct timer_list       timeout_timer;
125 };
126 
127 /* Register indices */
128 typedef enum {
129         reg_mode = 0,
130         reg_control,
131         reg_status,
132         reg_isr,
133         reg_ier,
134         reg_addr,
135         reg_subaddr,
136         reg_data
137 } reg_t;
138 
139 /* The Tumbler audio equalizer can be really slow sometimes */
140 #define KW_POLL_TIMEOUT         (2*HZ)
141 
142 /* Mode register */
143 #define KW_I2C_MODE_100KHZ      0x00
144 #define KW_I2C_MODE_50KHZ       0x01
145 #define KW_I2C_MODE_25KHZ       0x02
146 #define KW_I2C_MODE_DUMB        0x00
147 #define KW_I2C_MODE_STANDARD    0x04
148 #define KW_I2C_MODE_STANDARDSUB 0x08
149 #define KW_I2C_MODE_COMBINED    0x0C
150 #define KW_I2C_MODE_MODE_MASK   0x0C
151 #define KW_I2C_MODE_CHAN_MASK   0xF0
152 
153 /* Control register */
154 #define KW_I2C_CTL_AAK          0x01
155 #define KW_I2C_CTL_XADDR        0x02
156 #define KW_I2C_CTL_STOP         0x04
157 #define KW_I2C_CTL_START        0x08
158 
159 /* Status register */
160 #define KW_I2C_STAT_BUSY        0x01
161 #define KW_I2C_STAT_LAST_AAK    0x02
162 #define KW_I2C_STAT_LAST_RW     0x04
163 #define KW_I2C_STAT_SDA         0x08
164 #define KW_I2C_STAT_SCL         0x10
165 
166 /* IER & ISR registers */
167 #define KW_I2C_IRQ_DATA         0x01
168 #define KW_I2C_IRQ_ADDR         0x02
169 #define KW_I2C_IRQ_STOP         0x04
170 #define KW_I2C_IRQ_START        0x08
171 #define KW_I2C_IRQ_MASK         0x0F
172 
173 /* State machine states */
174 enum {
175         state_idle,
176         state_addr,
177         state_read,
178         state_write,
179         state_stop,
180         state_dead
181 };
182 
183 #define WRONG_STATE(name) do {\
184                 printk(KERN_DEBUG "KW: wrong state. Got %s, state: %s " \
185                        "(isr: %02x)\n", \
186                        name, __kw_state_names[host->state], isr); \
187         } while(0)
188 
189 static const char *__kw_state_names[] = {
190         "state_idle",
191         "state_addr",
192         "state_read",
193         "state_write",
194         "state_stop",
195         "state_dead"
196 };
197 
198 static inline u8 __kw_read_reg(struct pmac_i2c_host_kw *host, reg_t reg)
199 {
200         return readb(host->base + (((unsigned int)reg) << host->bsteps));
201 }
202 
203 static inline void __kw_write_reg(struct pmac_i2c_host_kw *host,
204                                   reg_t reg, u8 val)
205 {
206         writeb(val, host->base + (((unsigned)reg) << host->bsteps));
207         (void)__kw_read_reg(host, reg_subaddr);
208 }
209 
210 #define kw_write_reg(reg, val)  __kw_write_reg(host, reg, val)
211 #define kw_read_reg(reg)        __kw_read_reg(host, reg)
212 
213 static u8 kw_i2c_wait_interrupt(struct pmac_i2c_host_kw *host)
214 {
215         int i, j;
216         u8 isr;
217         
218         for (i = 0; i < 1000; i++) {
219                 isr = kw_read_reg(reg_isr) & KW_I2C_IRQ_MASK;
220                 if (isr != 0)
221                         return isr;
222 
223                 /* This code is used with the timebase frozen, we cannot rely
224                  * on udelay nor schedule when in polled mode !
225                  * For now, just use a bogus loop....
226                  */
227                 if (host->polled) {
228                         for (j = 1; j < 100000; j++)
229                                 mb();
230                 } else
231                         msleep(1);
232         }
233         return isr;
234 }
235 
236 static void kw_i2c_do_stop(struct pmac_i2c_host_kw *host, int result)
237 {
238         kw_write_reg(reg_control, KW_I2C_CTL_STOP);
239         host->state = state_stop;
240         host->result = result;
241 }
242 
243 
244 static void kw_i2c_handle_interrupt(struct pmac_i2c_host_kw *host, u8 isr)
245 {
246         u8 ack;
247 
248         DBG_LOW("kw_handle_interrupt(%s, isr: %x)\n",
249                 __kw_state_names[host->state], isr);
250 
251         if (host->state == state_idle) {
252                 printk(KERN_WARNING "low_i2c: Keywest got an out of state"
253                        " interrupt, ignoring\n");
254                 kw_write_reg(reg_isr, isr);
255                 return;
256         }
257 
258         if (isr == 0) {
259                 printk(KERN_WARNING "low_i2c: Timeout in i2c transfer"
260                        " on keywest !\n");
261                 if (host->state != state_stop) {
262                         kw_i2c_do_stop(host, -EIO);
263                         return;
264                 }
265                 ack = kw_read_reg(reg_status);
266                 if (ack & KW_I2C_STAT_BUSY)
267                         kw_write_reg(reg_status, 0);
268                 host->state = state_idle;
269                 kw_write_reg(reg_ier, 0x00);
270                 if (!host->polled)
271                         complete(&host->complete);
272                 return;
273         }
274 
275         if (isr & KW_I2C_IRQ_ADDR) {
276                 ack = kw_read_reg(reg_status);
277                 if (host->state != state_addr) {
278                         WRONG_STATE("KW_I2C_IRQ_ADDR"); 
279                         kw_i2c_do_stop(host, -EIO);
280                 }
281                 if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
282                         host->result = -ENXIO;
283                         host->state = state_stop;
284                         DBG_LOW("KW: NAK on address\n");
285                 } else {
286                         if (host->len == 0)
287                                 kw_i2c_do_stop(host, 0);
288                         else if (host->rw) {
289                                 host->state = state_read;
290                                 if (host->len > 1)
291                                         kw_write_reg(reg_control,
292                                                      KW_I2C_CTL_AAK);
293                         } else {
294                                 host->state = state_write;
295                                 kw_write_reg(reg_data, *(host->data++));
296                                 host->len--;
297                         }
298                 }
299                 kw_write_reg(reg_isr, KW_I2C_IRQ_ADDR);
300         }
301 
302         if (isr & KW_I2C_IRQ_DATA) {
303                 if (host->state == state_read) {
304                         *(host->data++) = kw_read_reg(reg_data);
305                         host->len--;
306                         kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
307                         if (host->len == 0)
308                                 host->state = state_stop;
309                         else if (host->len == 1)
310                                 kw_write_reg(reg_control, 0);
311                 } else if (host->state == state_write) {
312                         ack = kw_read_reg(reg_status);
313                         if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
314                                 DBG_LOW("KW: nack on data write\n");
315                                 host->result = -EFBIG;
316                                 host->state = state_stop;
317                         } else if (host->len) {
318                                 kw_write_reg(reg_data, *(host->data++));
319                                 host->len--;
320                         } else
321                                 kw_i2c_do_stop(host, 0);
322                 } else {
323                         WRONG_STATE("KW_I2C_IRQ_DATA"); 
324                         if (host->state != state_stop)
325                                 kw_i2c_do_stop(host, -EIO);
326                 }
327                 kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
328         }
329 
330         if (isr & KW_I2C_IRQ_STOP) {
331                 kw_write_reg(reg_isr, KW_I2C_IRQ_STOP);
332                 if (host->state != state_stop) {
333                         WRONG_STATE("KW_I2C_IRQ_STOP");
334                         host->result = -EIO;
335                 }
336                 host->state = state_idle;
337                 if (!host->polled)
338                         complete(&host->complete);
339         }
340 
341         /* Below should only happen in manual mode which we don't use ... */
342         if (isr & KW_I2C_IRQ_START)
343                 kw_write_reg(reg_isr, KW_I2C_IRQ_START);
344 
345 }
346 
347 /* Interrupt handler */
348 static irqreturn_t kw_i2c_irq(int irq, void *dev_id)
349 {
350         struct pmac_i2c_host_kw *host = dev_id;
351         unsigned long flags;
352 
353         spin_lock_irqsave(&host->lock, flags);
354         del_timer(&host->timeout_timer);
355         kw_i2c_handle_interrupt(host, kw_read_reg(reg_isr));
356         if (host->state != state_idle) {
357                 host->timeout_timer.expires = jiffies + KW_POLL_TIMEOUT;
358                 add_timer(&host->timeout_timer);
359         }
360         spin_unlock_irqrestore(&host->lock, flags);
361         return IRQ_HANDLED;
362 }
363 
364 static void kw_i2c_timeout(struct timer_list *t)
365 {
366         struct pmac_i2c_host_kw *host = from_timer(host, t, timeout_timer);
367         unsigned long flags;
368 
369         spin_lock_irqsave(&host->lock, flags);
370 
371         /*
372          * If the timer is pending, that means we raced with the
373          * irq, in which case we just return
374          */
375         if (timer_pending(&host->timeout_timer))
376                 goto skip;
377 
378         kw_i2c_handle_interrupt(host, kw_read_reg(reg_isr));
379         if (host->state != state_idle) {
380                 host->timeout_timer.expires = jiffies + KW_POLL_TIMEOUT;
381                 add_timer(&host->timeout_timer);
382         }
383  skip:
384         spin_unlock_irqrestore(&host->lock, flags);
385 }
386 
387 static int kw_i2c_open(struct pmac_i2c_bus *bus)
388 {
389         struct pmac_i2c_host_kw *host = bus->hostdata;
390         mutex_lock(&host->mutex);
391         return 0;
392 }
393 
394 static void kw_i2c_close(struct pmac_i2c_bus *bus)
395 {
396         struct pmac_i2c_host_kw *host = bus->hostdata;
397         mutex_unlock(&host->mutex);
398 }
399 
400 static int kw_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
401                        u32 subaddr, u8 *data, int len)
402 {
403         struct pmac_i2c_host_kw *host = bus->hostdata;
404         u8 mode_reg = host->speed;
405         int use_irq = host->irq && !bus->polled;
406 
407         /* Setup mode & subaddress if any */
408         switch(bus->mode) {
409         case pmac_i2c_mode_dumb:
410                 return -EINVAL;
411         case pmac_i2c_mode_std:
412                 mode_reg |= KW_I2C_MODE_STANDARD;
413                 if (subsize != 0)
414                         return -EINVAL;
415                 break;
416         case pmac_i2c_mode_stdsub:
417                 mode_reg |= KW_I2C_MODE_STANDARDSUB;
418                 if (subsize != 1)
419                         return -EINVAL;
420                 break;
421         case pmac_i2c_mode_combined:
422                 mode_reg |= KW_I2C_MODE_COMBINED;
423                 if (subsize != 1)
424                         return -EINVAL;
425                 break;
426         }
427 
428         /* Setup channel & clear pending irqs */
429         kw_write_reg(reg_isr, kw_read_reg(reg_isr));
430         kw_write_reg(reg_mode, mode_reg | (bus->channel << 4));
431         kw_write_reg(reg_status, 0);
432 
433         /* Set up address and r/w bit, strip possible stale bus number from
434          * address top bits
435          */
436         kw_write_reg(reg_addr, addrdir & 0xff);
437 
438         /* Set up the sub address */
439         if ((mode_reg & KW_I2C_MODE_MODE_MASK) == KW_I2C_MODE_STANDARDSUB
440             || (mode_reg & KW_I2C_MODE_MODE_MASK) == KW_I2C_MODE_COMBINED)
441                 kw_write_reg(reg_subaddr, subaddr);
442 
443         /* Prepare for async operations */
444         host->data = data;
445         host->len = len;
446         host->state = state_addr;
447         host->result = 0;
448         host->rw = (addrdir & 1);
449         host->polled = bus->polled;
450 
451         /* Enable interrupt if not using polled mode and interrupt is
452          * available
453          */
454         if (use_irq) {
455                 /* Clear completion */
456                 reinit_completion(&host->complete);
457                 /* Ack stale interrupts */
458                 kw_write_reg(reg_isr, kw_read_reg(reg_isr));
459                 /* Arm timeout */
460                 host->timeout_timer.expires = jiffies + KW_POLL_TIMEOUT;
461                 add_timer(&host->timeout_timer);
462                 /* Enable emission */
463                 kw_write_reg(reg_ier, KW_I2C_IRQ_MASK);
464         }
465 
466         /* Start sending address */
467         kw_write_reg(reg_control, KW_I2C_CTL_XADDR);
468 
469         /* Wait for completion */
470         if (use_irq)
471                 wait_for_completion(&host->complete);
472         else {
473                 while(host->state != state_idle) {
474                         unsigned long flags;
475 
476                         u8 isr = kw_i2c_wait_interrupt(host);
477                         spin_lock_irqsave(&host->lock, flags);
478                         kw_i2c_handle_interrupt(host, isr);
479                         spin_unlock_irqrestore(&host->lock, flags);
480                 }
481         }
482 
483         /* Disable emission */
484         kw_write_reg(reg_ier, 0);
485 
486         return host->result;
487 }
488 
489 static struct pmac_i2c_host_kw *__init kw_i2c_host_init(struct device_node *np)
490 {
491         struct pmac_i2c_host_kw *host;
492         const u32               *psteps, *prate, *addrp;
493         u32                     steps;
494 
495         host = kzalloc(sizeof(*host), GFP_KERNEL);
496         if (host == NULL) {
497                 printk(KERN_ERR "low_i2c: Can't allocate host for %pOF\n",
498                        np);
499                 return NULL;
500         }
501 
502         /* Apple is kind enough to provide a valid AAPL,address property
503          * on all i2c keywest nodes so far ... we would have to fallback
504          * to macio parsing if that wasn't the case
505          */
506         addrp = of_get_property(np, "AAPL,address", NULL);
507         if (addrp == NULL) {
508                 printk(KERN_ERR "low_i2c: Can't find address for %pOF\n",
509                        np);
510                 kfree(host);
511                 return NULL;
512         }
513         mutex_init(&host->mutex);
514         init_completion(&host->complete);
515         spin_lock_init(&host->lock);
516         timer_setup(&host->timeout_timer, kw_i2c_timeout, 0);
517 
518         psteps = of_get_property(np, "AAPL,address-step", NULL);
519         steps = psteps ? (*psteps) : 0x10;
520         for (host->bsteps = 0; (steps & 0x01) == 0; host->bsteps++)
521                 steps >>= 1;
522         /* Select interface rate */
523         host->speed = KW_I2C_MODE_25KHZ;
524         prate = of_get_property(np, "AAPL,i2c-rate", NULL);
525         if (prate) switch(*prate) {
526         case 100:
527                 host->speed = KW_I2C_MODE_100KHZ;
528                 break;
529         case 50:
530                 host->speed = KW_I2C_MODE_50KHZ;
531                 break;
532         case 25:
533                 host->speed = KW_I2C_MODE_25KHZ;
534                 break;
535         }       
536         host->irq = irq_of_parse_and_map(np, 0);
537         if (!host->irq)
538                 printk(KERN_WARNING
539                        "low_i2c: Failed to map interrupt for %pOF\n",
540                        np);
541 
542         host->base = ioremap((*addrp), 0x1000);
543         if (host->base == NULL) {
544                 printk(KERN_ERR "low_i2c: Can't map registers for %pOF\n",
545                        np);
546                 kfree(host);
547                 return NULL;
548         }
549 
550         /* Make sure IRQ is disabled */
551         kw_write_reg(reg_ier, 0);
552 
553         /* Request chip interrupt. We set IRQF_NO_SUSPEND because we don't
554          * want that interrupt disabled between the 2 passes of driver
555          * suspend or we'll have issues running the pfuncs
556          */
557         if (request_irq(host->irq, kw_i2c_irq, IRQF_NO_SUSPEND,
558                         "keywest i2c", host))
559                 host->irq = 0;
560 
561         printk(KERN_INFO "KeyWest i2c @0x%08x irq %d %pOF\n",
562                *addrp, host->irq, np);
563 
564         return host;
565 }
566 
567 
568 static void __init kw_i2c_add(struct pmac_i2c_host_kw *host,
569                               struct device_node *controller,
570                               struct device_node *busnode,
571                               int channel)
572 {
573         struct pmac_i2c_bus *bus;
574 
575         bus = kzalloc(sizeof(struct pmac_i2c_bus), GFP_KERNEL);
576         if (bus == NULL)
577                 return;
578 
579         bus->controller = of_node_get(controller);
580         bus->busnode = of_node_get(busnode);
581         bus->type = pmac_i2c_bus_keywest;
582         bus->hostdata = host;
583         bus->channel = channel;
584         bus->mode = pmac_i2c_mode_std;
585         bus->open = kw_i2c_open;
586         bus->close = kw_i2c_close;
587         bus->xfer = kw_i2c_xfer;
588         mutex_init(&bus->mutex);
589         lockdep_set_class(&bus->mutex, &bus->lock_key);
590         if (controller == busnode)
591                 bus->flags = pmac_i2c_multibus;
592         list_add(&bus->link, &pmac_i2c_busses);
593 
594         printk(KERN_INFO " channel %d bus %s\n", channel,
595                (controller == busnode) ? "<multibus>" : busnode->full_name);
596 }
597 
598 static void __init kw_i2c_probe(void)
599 {
600         struct device_node *np, *child, *parent;
601 
602         /* Probe keywest-i2c busses */
603         for_each_compatible_node(np, "i2c","keywest-i2c") {
604                 struct pmac_i2c_host_kw *host;
605                 int multibus;
606 
607                 /* Found one, init a host structure */
608                 host = kw_i2c_host_init(np);
609                 if (host == NULL)
610                         continue;
611 
612                 /* Now check if we have a multibus setup (old style) or if we
613                  * have proper bus nodes. Note that the "new" way (proper bus
614                  * nodes) might cause us to not create some busses that are
615                  * kept hidden in the device-tree. In the future, we might
616                  * want to work around that by creating busses without a node
617                  * but not for now
618                  */
619                 child = of_get_next_child(np, NULL);
620                 multibus = !child || strcmp(child->name, "i2c-bus");
621                 of_node_put(child);
622 
623                 /* For a multibus setup, we get the bus count based on the
624                  * parent type
625                  */
626                 if (multibus) {
627                         int chans, i;
628 
629                         parent = of_get_parent(np);
630                         if (parent == NULL)
631                                 continue;
632                         chans = parent->name[0] == 'u' ? 2 : 1;
633                         for (i = 0; i < chans; i++)
634                                 kw_i2c_add(host, np, np, i);
635                 } else {
636                         for (child = NULL;
637                              (child = of_get_next_child(np, child)) != NULL;) {
638                                 const u32 *reg = of_get_property(child,
639                                                 "reg", NULL);
640                                 if (reg == NULL)
641                                         continue;
642                                 kw_i2c_add(host, np, child, *reg);
643                         }
644                 }
645         }
646 }
647 
648 
649 /*
650  *
651  * PMU implementation
652  *
653  */
654 
655 #ifdef CONFIG_ADB_PMU
656 
657 /*
658  * i2c command block to the PMU
659  */
660 struct pmu_i2c_hdr {
661         u8      bus;
662         u8      mode;
663         u8      bus2;
664         u8      address;
665         u8      sub_addr;
666         u8      comb_addr;
667         u8      count;
668         u8      data[];
669 };
670 
671 static void pmu_i2c_complete(struct adb_request *req)
672 {
673         complete(req->arg);
674 }
675 
676 static int pmu_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
677                         u32 subaddr, u8 *data, int len)
678 {
679         struct adb_request *req = bus->hostdata;
680         struct pmu_i2c_hdr *hdr = (struct pmu_i2c_hdr *)&req->data[1];
681         struct completion comp;
682         int read = addrdir & 1;
683         int retry;
684         int rc = 0;
685 
686         /* For now, limit ourselves to 16 bytes transfers */
687         if (len > 16)
688                 return -EINVAL;
689 
690         init_completion(&comp);
691 
692         for (retry = 0; retry < 16; retry++) {
693                 memset(req, 0, sizeof(struct adb_request));
694                 hdr->bus = bus->channel;
695                 hdr->count = len;
696 
697                 switch(bus->mode) {
698                 case pmac_i2c_mode_std:
699                         if (subsize != 0)
700                                 return -EINVAL;
701                         hdr->address = addrdir;
702                         hdr->mode = PMU_I2C_MODE_SIMPLE;
703                         break;
704                 case pmac_i2c_mode_stdsub:
705                 case pmac_i2c_mode_combined:
706                         if (subsize != 1)
707                                 return -EINVAL;
708                         hdr->address = addrdir & 0xfe;
709                         hdr->comb_addr = addrdir;
710                         hdr->sub_addr = subaddr;
711                         if (bus->mode == pmac_i2c_mode_stdsub)
712                                 hdr->mode = PMU_I2C_MODE_STDSUB;
713                         else
714                                 hdr->mode = PMU_I2C_MODE_COMBINED;
715                         break;
716                 default:
717                         return -EINVAL;
718                 }
719 
720                 reinit_completion(&comp);
721                 req->data[0] = PMU_I2C_CMD;
722                 req->reply[0] = 0xff;
723                 req->nbytes = sizeof(struct pmu_i2c_hdr) + 1;
724                 req->done = pmu_i2c_complete;
725                 req->arg = &comp;
726                 if (!read && len) {
727                         memcpy(hdr->data, data, len);
728                         req->nbytes += len;
729                 }
730                 rc = pmu_queue_request(req);
731                 if (rc)
732                         return rc;
733                 wait_for_completion(&comp);
734                 if (req->reply[0] == PMU_I2C_STATUS_OK)
735                         break;
736                 msleep(15);
737         }
738         if (req->reply[0] != PMU_I2C_STATUS_OK)
739                 return -EIO;
740 
741         for (retry = 0; retry < 16; retry++) {
742                 memset(req, 0, sizeof(struct adb_request));
743 
744                 /* I know that looks like a lot, slow as hell, but darwin
745                  * does it so let's be on the safe side for now
746                  */
747                 msleep(15);
748 
749                 hdr->bus = PMU_I2C_BUS_STATUS;
750 
751                 reinit_completion(&comp);
752                 req->data[0] = PMU_I2C_CMD;
753                 req->reply[0] = 0xff;
754                 req->nbytes = 2;
755                 req->done = pmu_i2c_complete;
756                 req->arg = &comp;
757                 rc = pmu_queue_request(req);
758                 if (rc)
759                         return rc;
760                 wait_for_completion(&comp);
761 
762                 if (req->reply[0] == PMU_I2C_STATUS_OK && !read)
763                         return 0;
764                 if (req->reply[0] == PMU_I2C_STATUS_DATAREAD && read) {
765                         int rlen = req->reply_len - 1;
766 
767                         if (rlen != len) {
768                                 printk(KERN_WARNING "low_i2c: PMU returned %d"
769                                        " bytes, expected %d !\n", rlen, len);
770                                 return -EIO;
771                         }
772                         if (len)
773                                 memcpy(data, &req->reply[1], len);
774                         return 0;
775                 }
776         }
777         return -EIO;
778 }
779 
780 static void __init pmu_i2c_probe(void)
781 {
782         struct pmac_i2c_bus *bus;
783         struct device_node *busnode;
784         int channel, sz;
785 
786         if (!pmu_present())
787                 return;
788 
789         /* There might or might not be a "pmu-i2c" node, we use that
790          * or via-pmu itself, whatever we find. I haven't seen a machine
791          * with separate bus nodes, so we assume a multibus setup
792          */
793         busnode = of_find_node_by_name(NULL, "pmu-i2c");
794         if (busnode == NULL)
795                 busnode = of_find_node_by_name(NULL, "via-pmu");
796         if (busnode == NULL)
797                 return;
798 
799         printk(KERN_INFO "PMU i2c %pOF\n", busnode);
800 
801         /*
802          * We add bus 1 and 2 only for now, bus 0 is "special"
803          */
804         for (channel = 1; channel <= 2; channel++) {
805                 sz = sizeof(struct pmac_i2c_bus) + sizeof(struct adb_request);
806                 bus = kzalloc(sz, GFP_KERNEL);
807                 if (bus == NULL)
808                         return;
809 
810                 bus->controller = busnode;
811                 bus->busnode = busnode;
812                 bus->type = pmac_i2c_bus_pmu;
813                 bus->channel = channel;
814                 bus->mode = pmac_i2c_mode_std;
815                 bus->hostdata = bus + 1;
816                 bus->xfer = pmu_i2c_xfer;
817                 mutex_init(&bus->mutex);
818                 lockdep_set_class(&bus->mutex, &bus->lock_key);
819                 bus->flags = pmac_i2c_multibus;
820                 list_add(&bus->link, &pmac_i2c_busses);
821 
822                 printk(KERN_INFO " channel %d bus <multibus>\n", channel);
823         }
824 }
825 
826 #endif /* CONFIG_ADB_PMU */
827 
828 
829 /*
830  *
831  * SMU implementation
832  *
833  */
834 
835 #ifdef CONFIG_PMAC_SMU
836 
837 static void smu_i2c_complete(struct smu_i2c_cmd *cmd, void *misc)
838 {
839         complete(misc);
840 }
841 
842 static int smu_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
843                         u32 subaddr, u8 *data, int len)
844 {
845         struct smu_i2c_cmd *cmd = bus->hostdata;
846         struct completion comp;
847         int read = addrdir & 1;
848         int rc = 0;
849 
850         if ((read && len > SMU_I2C_READ_MAX) ||
851             ((!read) && len > SMU_I2C_WRITE_MAX))
852                 return -EINVAL;
853 
854         memset(cmd, 0, sizeof(struct smu_i2c_cmd));
855         cmd->info.bus = bus->channel;
856         cmd->info.devaddr = addrdir;
857         cmd->info.datalen = len;
858 
859         switch(bus->mode) {
860         case pmac_i2c_mode_std:
861                 if (subsize != 0)
862                         return -EINVAL;
863                 cmd->info.type = SMU_I2C_TRANSFER_SIMPLE;
864                 break;
865         case pmac_i2c_mode_stdsub:
866         case pmac_i2c_mode_combined:
867                 if (subsize > 3 || subsize < 1)
868                         return -EINVAL;
869                 cmd->info.sublen = subsize;
870                 /* that's big-endian only but heh ! */
871                 memcpy(&cmd->info.subaddr, ((char *)&subaddr) + (4 - subsize),
872                        subsize);
873                 if (bus->mode == pmac_i2c_mode_stdsub)
874                         cmd->info.type = SMU_I2C_TRANSFER_STDSUB;
875                 else
876                         cmd->info.type = SMU_I2C_TRANSFER_COMBINED;
877                 break;
878         default:
879                 return -EINVAL;
880         }
881         if (!read && len)
882                 memcpy(cmd->info.data, data, len);
883 
884         init_completion(&comp);
885         cmd->done = smu_i2c_complete;
886         cmd->misc = &comp;
887         rc = smu_queue_i2c(cmd);
888         if (rc < 0)
889                 return rc;
890         wait_for_completion(&comp);
891         rc = cmd->status;
892 
893         if (read && len)
894                 memcpy(data, cmd->info.data, len);
895         return rc < 0 ? rc : 0;
896 }
897 
898 static void __init smu_i2c_probe(void)
899 {
900         struct device_node *controller, *busnode;
901         struct pmac_i2c_bus *bus;
902         const u32 *reg;
903         int sz;
904 
905         if (!smu_present())
906                 return;
907 
908         controller = of_find_node_by_name(NULL, "smu-i2c-control");
909         if (controller == NULL)
910                 controller = of_find_node_by_name(NULL, "smu");
911         if (controller == NULL)
912                 return;
913 
914         printk(KERN_INFO "SMU i2c %pOF\n", controller);
915 
916         /* Look for childs, note that they might not be of the right
917          * type as older device trees mix i2c busses and other things
918          * at the same level
919          */
920         for (busnode = NULL;
921              (busnode = of_get_next_child(controller, busnode)) != NULL;) {
922                 if (strcmp(busnode->type, "i2c") &&
923                     strcmp(busnode->type, "i2c-bus"))
924                         continue;
925                 reg = of_get_property(busnode, "reg", NULL);
926                 if (reg == NULL)
927                         continue;
928 
929                 sz = sizeof(struct pmac_i2c_bus) + sizeof(struct smu_i2c_cmd);
930                 bus = kzalloc(sz, GFP_KERNEL);
931                 if (bus == NULL)
932                         return;
933 
934                 bus->controller = controller;
935                 bus->busnode = of_node_get(busnode);
936                 bus->type = pmac_i2c_bus_smu;
937                 bus->channel = *reg;
938                 bus->mode = pmac_i2c_mode_std;
939                 bus->hostdata = bus + 1;
940                 bus->xfer = smu_i2c_xfer;
941                 mutex_init(&bus->mutex);
942                 lockdep_set_class(&bus->mutex, &bus->lock_key);
943                 bus->flags = 0;
944                 list_add(&bus->link, &pmac_i2c_busses);
945 
946                 printk(KERN_INFO " channel %x bus %pOF\n",
947                        bus->channel, busnode);
948         }
949 }
950 
951 #endif /* CONFIG_PMAC_SMU */
952 
953 /*
954  *
955  * Core code
956  *
957  */
958 
959 
960 struct pmac_i2c_bus *pmac_i2c_find_bus(struct device_node *node)
961 {
962         struct device_node *p = of_node_get(node);
963         struct device_node *prev = NULL;
964         struct pmac_i2c_bus *bus;
965 
966         while(p) {
967                 list_for_each_entry(bus, &pmac_i2c_busses, link) {
968                         if (p == bus->busnode) {
969                                 if (prev && bus->flags & pmac_i2c_multibus) {
970                                         const u32 *reg;
971                                         reg = of_get_property(prev, "reg",
972                                                                 NULL);
973                                         if (!reg)
974                                                 continue;
975                                         if (((*reg) >> 8) != bus->channel)
976                                                 continue;
977                                 }
978                                 of_node_put(p);
979                                 of_node_put(prev);
980                                 return bus;
981                         }
982                 }
983                 of_node_put(prev);
984                 prev = p;
985                 p = of_get_parent(p);
986         }
987         return NULL;
988 }
989 EXPORT_SYMBOL_GPL(pmac_i2c_find_bus);
990 
991 u8 pmac_i2c_get_dev_addr(struct device_node *device)
992 {
993         const u32 *reg = of_get_property(device, "reg", NULL);
994 
995         if (reg == NULL)
996                 return 0;
997 
998         return (*reg) & 0xff;
999 }
1000 EXPORT_SYMBOL_GPL(pmac_i2c_get_dev_addr);
1001 
1002 struct device_node *pmac_i2c_get_controller(struct pmac_i2c_bus *bus)
1003 {
1004         return bus->controller;
1005 }
1006 EXPORT_SYMBOL_GPL(pmac_i2c_get_controller);
1007 
1008 struct device_node *pmac_i2c_get_bus_node(struct pmac_i2c_bus *bus)
1009 {
1010         return bus->busnode;
1011 }
1012 EXPORT_SYMBOL_GPL(pmac_i2c_get_bus_node);
1013 
1014 int pmac_i2c_get_type(struct pmac_i2c_bus *bus)
1015 {
1016         return bus->type;
1017 }
1018 EXPORT_SYMBOL_GPL(pmac_i2c_get_type);
1019 
1020 int pmac_i2c_get_flags(struct pmac_i2c_bus *bus)
1021 {
1022         return bus->flags;
1023 }
1024 EXPORT_SYMBOL_GPL(pmac_i2c_get_flags);
1025 
1026 int pmac_i2c_get_channel(struct pmac_i2c_bus *bus)
1027 {
1028         return bus->channel;
1029 }
1030 EXPORT_SYMBOL_GPL(pmac_i2c_get_channel);
1031 
1032 
1033 struct i2c_adapter *pmac_i2c_get_adapter(struct pmac_i2c_bus *bus)
1034 {
1035         return &bus->adapter;
1036 }
1037 EXPORT_SYMBOL_GPL(pmac_i2c_get_adapter);
1038 
1039 struct pmac_i2c_bus *pmac_i2c_adapter_to_bus(struct i2c_adapter *adapter)
1040 {
1041         struct pmac_i2c_bus *bus;
1042 
1043         list_for_each_entry(bus, &pmac_i2c_busses, link)
1044                 if (&bus->adapter == adapter)
1045                         return bus;
1046         return NULL;
1047 }
1048 EXPORT_SYMBOL_GPL(pmac_i2c_adapter_to_bus);
1049 
1050 int pmac_i2c_match_adapter(struct device_node *dev, struct i2c_adapter *adapter)
1051 {
1052         struct pmac_i2c_bus *bus = pmac_i2c_find_bus(dev);
1053 
1054         if (bus == NULL)
1055                 return 0;
1056         return (&bus->adapter == adapter);
1057 }
1058 EXPORT_SYMBOL_GPL(pmac_i2c_match_adapter);
1059 
1060 int pmac_low_i2c_lock(struct device_node *np)
1061 {
1062         struct pmac_i2c_bus *bus, *found = NULL;
1063 
1064         list_for_each_entry(bus, &pmac_i2c_busses, link) {
1065                 if (np == bus->controller) {
1066                         found = bus;
1067                         break;
1068                 }
1069         }
1070         if (!found)
1071                 return -ENODEV;
1072         return pmac_i2c_open(bus, 0);
1073 }
1074 EXPORT_SYMBOL_GPL(pmac_low_i2c_lock);
1075 
1076 int pmac_low_i2c_unlock(struct device_node *np)
1077 {
1078         struct pmac_i2c_bus *bus, *found = NULL;
1079 
1080         list_for_each_entry(bus, &pmac_i2c_busses, link) {
1081                 if (np == bus->controller) {
1082                         found = bus;
1083                         break;
1084                 }
1085         }
1086         if (!found)
1087                 return -ENODEV;
1088         pmac_i2c_close(bus);
1089         return 0;
1090 }
1091 EXPORT_SYMBOL_GPL(pmac_low_i2c_unlock);
1092 
1093 
1094 int pmac_i2c_open(struct pmac_i2c_bus *bus, int polled)
1095 {
1096         int rc;
1097 
1098         mutex_lock(&bus->mutex);
1099         bus->polled = polled || pmac_i2c_force_poll;
1100         bus->opened = 1;
1101         bus->mode = pmac_i2c_mode_std;
1102         if (bus->open && (rc = bus->open(bus)) != 0) {
1103                 bus->opened = 0;
1104                 mutex_unlock(&bus->mutex);
1105                 return rc;
1106         }
1107         return 0;
1108 }
1109 EXPORT_SYMBOL_GPL(pmac_i2c_open);
1110 
1111 void pmac_i2c_close(struct pmac_i2c_bus *bus)
1112 {
1113         WARN_ON(!bus->opened);
1114         if (bus->close)
1115                 bus->close(bus);
1116         bus->opened = 0;
1117         mutex_unlock(&bus->mutex);
1118 }
1119 EXPORT_SYMBOL_GPL(pmac_i2c_close);
1120 
1121 int pmac_i2c_setmode(struct pmac_i2c_bus *bus, int mode)
1122 {
1123         WARN_ON(!bus->opened);
1124 
1125         /* Report me if you see the error below as there might be a new
1126          * "combined4" mode that I need to implement for the SMU bus
1127          */
1128         if (mode < pmac_i2c_mode_dumb || mode > pmac_i2c_mode_combined) {
1129                 printk(KERN_ERR "low_i2c: Invalid mode %d requested on"
1130                        " bus %pOF !\n", mode, bus->busnode);
1131                 return -EINVAL;
1132         }
1133         bus->mode = mode;
1134 
1135         return 0;
1136 }
1137 EXPORT_SYMBOL_GPL(pmac_i2c_setmode);
1138 
1139 int pmac_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
1140                   u32 subaddr, u8 *data, int len)
1141 {
1142         int rc;
1143 
1144         WARN_ON(!bus->opened);
1145 
1146         DBG("xfer() chan=%d, addrdir=0x%x, mode=%d, subsize=%d, subaddr=0x%x,"
1147             " %d bytes, bus %pOF\n", bus->channel, addrdir, bus->mode, subsize,
1148             subaddr, len, bus->busnode);
1149 
1150         rc = bus->xfer(bus, addrdir, subsize, subaddr, data, len);
1151 
1152 #ifdef DEBUG
1153         if (rc)
1154                 DBG("xfer error %d\n", rc);
1155 #endif
1156         return rc;
1157 }
1158 EXPORT_SYMBOL_GPL(pmac_i2c_xfer);
1159 
1160 /* some quirks for platform function decoding */
1161 enum {
1162         pmac_i2c_quirk_invmask = 0x00000001u,
1163         pmac_i2c_quirk_skip = 0x00000002u,
1164 };
1165 
1166 static void pmac_i2c_devscan(void (*callback)(struct device_node *dev,
1167                                               int quirks))
1168 {
1169         struct pmac_i2c_bus *bus;
1170         struct device_node *np;
1171         static struct whitelist_ent {
1172                 char *name;
1173                 char *compatible;
1174                 int quirks;
1175         } whitelist[] = {
1176                 /* XXX Study device-tree's & apple drivers are get the quirks
1177                  * right !
1178                  */
1179                 /* Workaround: It seems that running the clockspreading
1180                  * properties on the eMac will cause lockups during boot.
1181                  * The machine seems to work fine without that. So for now,
1182                  * let's make sure i2c-hwclock doesn't match about "imic"
1183                  * clocks and we'll figure out if we really need to do
1184                  * something special about those later.
1185                  */
1186                 { "i2c-hwclock", "imic5002", pmac_i2c_quirk_skip },
1187                 { "i2c-hwclock", "imic5003", pmac_i2c_quirk_skip },
1188                 { "i2c-hwclock", NULL, pmac_i2c_quirk_invmask },
1189                 { "i2c-cpu-voltage", NULL, 0},
1190                 {  "temp-monitor", NULL, 0 },
1191                 {  "supply-monitor", NULL, 0 },
1192                 { NULL, NULL, 0 },
1193         };
1194 
1195         /* Only some devices need to have platform functions instantiated
1196          * here. For now, we have a table. Others, like 9554 i2c GPIOs used
1197          * on Xserve, if we ever do a driver for them, will use their own
1198          * platform function instance
1199          */
1200         list_for_each_entry(bus, &pmac_i2c_busses, link) {
1201                 for (np = NULL;
1202                      (np = of_get_next_child(bus->busnode, np)) != NULL;) {
1203                         struct whitelist_ent *p;
1204                         /* If multibus, check if device is on that bus */
1205                         if (bus->flags & pmac_i2c_multibus)
1206                                 if (bus != pmac_i2c_find_bus(np))
1207                                         continue;
1208                         for (p = whitelist; p->name != NULL; p++) {
1209                                 if (strcmp(np->name, p->name))
1210                                         continue;
1211                                 if (p->compatible &&
1212                                     !of_device_is_compatible(np, p->compatible))
1213                                         continue;
1214                                 if (p->quirks & pmac_i2c_quirk_skip)
1215                                         break;
1216                                 callback(np, p->quirks);
1217                                 break;
1218                         }
1219                 }
1220         }
1221 }
1222 
1223 #define MAX_I2C_DATA    64
1224 
1225 struct pmac_i2c_pf_inst
1226 {
1227         struct pmac_i2c_bus     *bus;
1228         u8                      addr;
1229         u8                      buffer[MAX_I2C_DATA];
1230         u8                      scratch[MAX_I2C_DATA];
1231         int                     bytes;
1232         int                     quirks;
1233 };
1234 
1235 static void* pmac_i2c_do_begin(struct pmf_function *func, struct pmf_args *args)
1236 {
1237         struct pmac_i2c_pf_inst *inst;
1238         struct pmac_i2c_bus     *bus;
1239 
1240         bus = pmac_i2c_find_bus(func->node);
1241         if (bus == NULL) {
1242                 printk(KERN_ERR "low_i2c: Can't find bus for %pOF (pfunc)\n",
1243                        func->node);
1244                 return NULL;
1245         }
1246         if (pmac_i2c_open(bus, 0)) {
1247                 printk(KERN_ERR "low_i2c: Can't open i2c bus for %pOF (pfunc)\n",
1248                        func->node);
1249                 return NULL;
1250         }
1251 
1252         /* XXX might need GFP_ATOMIC when called during the suspend process,
1253          * but then, there are already lots of issues with suspending when
1254          * near OOM that need to be resolved, the allocator itself should
1255          * probably make GFP_NOIO implicit during suspend
1256          */
1257         inst = kzalloc(sizeof(struct pmac_i2c_pf_inst), GFP_KERNEL);
1258         if (inst == NULL) {
1259                 pmac_i2c_close(bus);
1260                 return NULL;
1261         }
1262         inst->bus = bus;
1263         inst->addr = pmac_i2c_get_dev_addr(func->node);
1264         inst->quirks = (int)(long)func->driver_data;
1265         return inst;
1266 }
1267 
1268 static void pmac_i2c_do_end(struct pmf_function *func, void *instdata)
1269 {
1270         struct pmac_i2c_pf_inst *inst = instdata;
1271 
1272         if (inst == NULL)
1273                 return;
1274         pmac_i2c_close(inst->bus);
1275         kfree(inst);
1276 }
1277 
1278 static int pmac_i2c_do_read(PMF_STD_ARGS, u32 len)
1279 {
1280         struct pmac_i2c_pf_inst *inst = instdata;
1281 
1282         inst->bytes = len;
1283         return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_read, 0, 0,
1284                              inst->buffer, len);
1285 }
1286 
1287 static int pmac_i2c_do_write(PMF_STD_ARGS, u32 len, const u8 *data)
1288 {
1289         struct pmac_i2c_pf_inst *inst = instdata;
1290 
1291         return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 0, 0,
1292                              (u8 *)data, len);
1293 }
1294 
1295 /* This function is used to do the masking & OR'ing for the "rmw" type
1296  * callbacks. Ze should apply the mask and OR in the values in the
1297  * buffer before writing back. The problem is that it seems that
1298  * various darwin drivers implement the mask/or differently, thus
1299  * we need to check the quirks first
1300  */
1301 static void pmac_i2c_do_apply_rmw(struct pmac_i2c_pf_inst *inst,
1302                                   u32 len, const u8 *mask, const u8 *val)
1303 {
1304         int i;
1305 
1306         if (inst->quirks & pmac_i2c_quirk_invmask) {
1307                 for (i = 0; i < len; i ++)
1308                         inst->scratch[i] = (inst->buffer[i] & mask[i]) | val[i];
1309         } else {
1310                 for (i = 0; i < len; i ++)
1311                         inst->scratch[i] = (inst->buffer[i] & ~mask[i])
1312                                 | (val[i] & mask[i]);
1313         }
1314 }
1315 
1316 static int pmac_i2c_do_rmw(PMF_STD_ARGS, u32 masklen, u32 valuelen,
1317                            u32 totallen, const u8 *maskdata,
1318                            const u8 *valuedata)
1319 {
1320         struct pmac_i2c_pf_inst *inst = instdata;
1321 
1322         if (masklen > inst->bytes || valuelen > inst->bytes ||
1323             totallen > inst->bytes || valuelen > masklen)
1324                 return -EINVAL;
1325 
1326         pmac_i2c_do_apply_rmw(inst, masklen, maskdata, valuedata);
1327 
1328         return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 0, 0,
1329                              inst->scratch, totallen);
1330 }
1331 
1332 static int pmac_i2c_do_read_sub(PMF_STD_ARGS, u8 subaddr, u32 len)
1333 {
1334         struct pmac_i2c_pf_inst *inst = instdata;
1335 
1336         inst->bytes = len;
1337         return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_read, 1, subaddr,
1338                              inst->buffer, len);
1339 }
1340 
1341 static int pmac_i2c_do_write_sub(PMF_STD_ARGS, u8 subaddr, u32 len,
1342                                      const u8 *data)
1343 {
1344         struct pmac_i2c_pf_inst *inst = instdata;
1345 
1346         return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 1,
1347                              subaddr, (u8 *)data, len);
1348 }
1349 
1350 static int pmac_i2c_do_set_mode(PMF_STD_ARGS, int mode)
1351 {
1352         struct pmac_i2c_pf_inst *inst = instdata;
1353 
1354         return pmac_i2c_setmode(inst->bus, mode);
1355 }
1356 
1357 static int pmac_i2c_do_rmw_sub(PMF_STD_ARGS, u8 subaddr, u32 masklen,
1358                                u32 valuelen, u32 totallen, const u8 *maskdata,
1359                                const u8 *valuedata)
1360 {
1361         struct pmac_i2c_pf_inst *inst = instdata;
1362 
1363         if (masklen > inst->bytes || valuelen > inst->bytes ||
1364             totallen > inst->bytes || valuelen > masklen)
1365                 return -EINVAL;
1366 
1367         pmac_i2c_do_apply_rmw(inst, masklen, maskdata, valuedata);
1368 
1369         return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 1,
1370                              subaddr, inst->scratch, totallen);
1371 }
1372 
1373 static int pmac_i2c_do_mask_and_comp(PMF_STD_ARGS, u32 len,
1374                                      const u8 *maskdata,
1375                                      const u8 *valuedata)
1376 {
1377         struct pmac_i2c_pf_inst *inst = instdata;
1378         int i, match;
1379 
1380         /* Get return value pointer, it's assumed to be a u32 */
1381         if (!args || !args->count || !args->u[0].p)
1382                 return -EINVAL;
1383 
1384         /* Check buffer */
1385         if (len > inst->bytes)
1386                 return -EINVAL;
1387 
1388         for (i = 0, match = 1; match && i < len; i ++)
1389                 if ((inst->buffer[i] & maskdata[i]) != valuedata[i])
1390                         match = 0;
1391         *args->u[0].p = match;
1392         return 0;
1393 }
1394 
1395 static int pmac_i2c_do_delay(PMF_STD_ARGS, u32 duration)
1396 {
1397         msleep((duration + 999) / 1000);
1398         return 0;
1399 }
1400 
1401 
1402 static struct pmf_handlers pmac_i2c_pfunc_handlers = {
1403         .begin                  = pmac_i2c_do_begin,
1404         .end                    = pmac_i2c_do_end,
1405         .read_i2c               = pmac_i2c_do_read,
1406         .write_i2c              = pmac_i2c_do_write,
1407         .rmw_i2c                = pmac_i2c_do_rmw,
1408         .read_i2c_sub           = pmac_i2c_do_read_sub,
1409         .write_i2c_sub          = pmac_i2c_do_write_sub,
1410         .rmw_i2c_sub            = pmac_i2c_do_rmw_sub,
1411         .set_i2c_mode           = pmac_i2c_do_set_mode,
1412         .mask_and_compare       = pmac_i2c_do_mask_and_comp,
1413         .delay                  = pmac_i2c_do_delay,
1414 };
1415 
1416 static void __init pmac_i2c_dev_create(struct device_node *np, int quirks)
1417 {
1418         DBG("dev_create(%pOF)\n", np);
1419 
1420         pmf_register_driver(np, &pmac_i2c_pfunc_handlers,
1421                             (void *)(long)quirks);
1422 }
1423 
1424 static void __init pmac_i2c_dev_init(struct device_node *np, int quirks)
1425 {
1426         DBG("dev_create(%pOF)\n", np);
1427 
1428         pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_INIT, NULL);
1429 }
1430 
1431 static void pmac_i2c_dev_suspend(struct device_node *np, int quirks)
1432 {
1433         DBG("dev_suspend(%pOF)\n", np);
1434         pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_SLEEP, NULL);
1435 }
1436 
1437 static void pmac_i2c_dev_resume(struct device_node *np, int quirks)
1438 {
1439         DBG("dev_resume(%pOF)\n", np);
1440         pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_WAKE, NULL);
1441 }
1442 
1443 void pmac_pfunc_i2c_suspend(void)
1444 {
1445         pmac_i2c_devscan(pmac_i2c_dev_suspend);
1446 }
1447 
1448 void pmac_pfunc_i2c_resume(void)
1449 {
1450         pmac_i2c_devscan(pmac_i2c_dev_resume);
1451 }
1452 
1453 /*
1454  * Initialize us: probe all i2c busses on the machine, instantiate
1455  * busses and platform functions as needed.
1456  */
1457 /* This is non-static as it might be called early by smp code */
1458 int __init pmac_i2c_init(void)
1459 {
1460         static int i2c_inited;
1461 
1462         if (i2c_inited)
1463                 return 0;
1464         i2c_inited = 1;
1465 
1466         /* Probe keywest-i2c busses */
1467         kw_i2c_probe();
1468 
1469 #ifdef CONFIG_ADB_PMU
1470         /* Probe PMU i2c busses */
1471         pmu_i2c_probe();
1472 #endif
1473 
1474 #ifdef CONFIG_PMAC_SMU
1475         /* Probe SMU i2c busses */
1476         smu_i2c_probe();
1477 #endif
1478 
1479         /* Now add plaform functions for some known devices */
1480         pmac_i2c_devscan(pmac_i2c_dev_create);
1481 
1482         return 0;
1483 }
1484 machine_arch_initcall(powermac, pmac_i2c_init);
1485 
1486 /* Since pmac_i2c_init can be called too early for the platform device
1487  * registration, we need to do it at a later time. In our case, subsys
1488  * happens to fit well, though I agree it's a bit of a hack...
1489  */
1490 static int __init pmac_i2c_create_platform_devices(void)
1491 {
1492         struct pmac_i2c_bus *bus;
1493         int i = 0;
1494 
1495         /* In the case where we are initialized from smp_init(), we must
1496          * not use the timer (and thus the irq). It's safe from now on
1497          * though
1498          */
1499         pmac_i2c_force_poll = 0;
1500 
1501         /* Create platform devices */
1502         list_for_each_entry(bus, &pmac_i2c_busses, link) {
1503                 bus->platform_dev =
1504                         platform_device_alloc("i2c-powermac", i++);
1505                 if (bus->platform_dev == NULL)
1506                         return -ENOMEM;
1507                 bus->platform_dev->dev.platform_data = bus;
1508                 bus->platform_dev->dev.of_node = bus->busnode;
1509                 platform_device_add(bus->platform_dev);
1510         }
1511 
1512         /* Now call platform "init" functions */
1513         pmac_i2c_devscan(pmac_i2c_dev_init);
1514 
1515         return 0;
1516 }
1517 machine_subsys_initcall(powermac, pmac_i2c_create_platform_devices);
1518 

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