KVM: Inject asynchronous page fault into a PV guest if page is swapped out.
[linux-2.6.git] / drivers / gpio / pca953x.c
1 /*
2  *  pca953x.c - 4/8/16 bit I/O ports
3  *
4  *  Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
5  *  Copyright (C) 2007 Marvell International Ltd.
6  *
7  *  Derived from drivers/i2c/chips/pca9539.c
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License as published by
11  *  the Free Software Foundation; version 2 of the License.
12  */
13
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/gpio.h>
17 #include <linux/interrupt.h>
18 #include <linux/irq.h>
19 #include <linux/i2c.h>
20 #include <linux/i2c/pca953x.h>
21 #include <linux/slab.h>
22 #ifdef CONFIG_OF_GPIO
23 #include <linux/of_platform.h>
24 #include <linux/of_gpio.h>
25 #endif
26
27 #define PCA953X_INPUT          0
28 #define PCA953X_OUTPUT         1
29 #define PCA953X_INVERT         2
30 #define PCA953X_DIRECTION      3
31
32 #define PCA953X_GPIOS          0x00FF
33 #define PCA953X_INT            0x0100
34
35 static const struct i2c_device_id pca953x_id[] = {
36         { "pca9534", 8  | PCA953X_INT, },
37         { "pca9535", 16 | PCA953X_INT, },
38         { "pca9536", 4, },
39         { "pca9537", 4  | PCA953X_INT, },
40         { "pca9538", 8  | PCA953X_INT, },
41         { "pca9539", 16 | PCA953X_INT, },
42         { "pca9554", 8  | PCA953X_INT, },
43         { "pca9555", 16 | PCA953X_INT, },
44         { "pca9556", 8, },
45         { "pca9557", 8, },
46
47         { "max7310", 8, },
48         { "max7312", 16 | PCA953X_INT, },
49         { "max7313", 16 | PCA953X_INT, },
50         { "max7315", 8  | PCA953X_INT, },
51         { "pca6107", 8  | PCA953X_INT, },
52         { "tca6408", 8  | PCA953X_INT, },
53         { "tca6416", 16 | PCA953X_INT, },
54         /* NYET:  { "tca6424", 24, }, */
55         { }
56 };
57 MODULE_DEVICE_TABLE(i2c, pca953x_id);
58
59 struct pca953x_chip {
60         unsigned gpio_start;
61         uint16_t reg_output;
62         uint16_t reg_direction;
63
64 #ifdef CONFIG_GPIO_PCA953X_IRQ
65         struct mutex irq_lock;
66         uint16_t irq_mask;
67         uint16_t irq_stat;
68         uint16_t irq_trig_raise;
69         uint16_t irq_trig_fall;
70         int      irq_base;
71 #endif
72
73         struct i2c_client *client;
74         struct pca953x_platform_data *dyn_pdata;
75         struct gpio_chip gpio_chip;
76         const char *const *names;
77 };
78
79 static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val)
80 {
81         int ret;
82
83         if (chip->gpio_chip.ngpio <= 8)
84                 ret = i2c_smbus_write_byte_data(chip->client, reg, val);
85         else
86                 ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);
87
88         if (ret < 0) {
89                 dev_err(&chip->client->dev, "failed writing register\n");
90                 return ret;
91         }
92
93         return 0;
94 }
95
96 static int pca953x_read_reg(struct pca953x_chip *chip, int reg, uint16_t *val)
97 {
98         int ret;
99
100         if (chip->gpio_chip.ngpio <= 8)
101                 ret = i2c_smbus_read_byte_data(chip->client, reg);
102         else
103                 ret = i2c_smbus_read_word_data(chip->client, reg << 1);
104
105         if (ret < 0) {
106                 dev_err(&chip->client->dev, "failed reading register\n");
107                 return ret;
108         }
109
110         *val = (uint16_t)ret;
111         return 0;
112 }
113
114 static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
115 {
116         struct pca953x_chip *chip;
117         uint16_t reg_val;
118         int ret;
119
120         chip = container_of(gc, struct pca953x_chip, gpio_chip);
121
122         reg_val = chip->reg_direction | (1u << off);
123         ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
124         if (ret)
125                 return ret;
126
127         chip->reg_direction = reg_val;
128         return 0;
129 }
130
131 static int pca953x_gpio_direction_output(struct gpio_chip *gc,
132                 unsigned off, int val)
133 {
134         struct pca953x_chip *chip;
135         uint16_t reg_val;
136         int ret;
137
138         chip = container_of(gc, struct pca953x_chip, gpio_chip);
139
140         /* set output level */
141         if (val)
142                 reg_val = chip->reg_output | (1u << off);
143         else
144                 reg_val = chip->reg_output & ~(1u << off);
145
146         ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
147         if (ret)
148                 return ret;
149
150         chip->reg_output = reg_val;
151
152         /* then direction */
153         reg_val = chip->reg_direction & ~(1u << off);
154         ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
155         if (ret)
156                 return ret;
157
158         chip->reg_direction = reg_val;
159         return 0;
160 }
161
162 static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
163 {
164         struct pca953x_chip *chip;
165         uint16_t reg_val;
166         int ret;
167
168         chip = container_of(gc, struct pca953x_chip, gpio_chip);
169
170         ret = pca953x_read_reg(chip, PCA953X_INPUT, &reg_val);
171         if (ret < 0) {
172                 /* NOTE:  diagnostic already emitted; that's all we should
173                  * do unless gpio_*_value_cansleep() calls become different
174                  * from their nonsleeping siblings (and report faults).
175                  */
176                 return 0;
177         }
178
179         return (reg_val & (1u << off)) ? 1 : 0;
180 }
181
182 static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
183 {
184         struct pca953x_chip *chip;
185         uint16_t reg_val;
186         int ret;
187
188         chip = container_of(gc, struct pca953x_chip, gpio_chip);
189
190         if (val)
191                 reg_val = chip->reg_output | (1u << off);
192         else
193                 reg_val = chip->reg_output & ~(1u << off);
194
195         ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
196         if (ret)
197                 return;
198
199         chip->reg_output = reg_val;
200 }
201
202 static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
203 {
204         struct gpio_chip *gc;
205
206         gc = &chip->gpio_chip;
207
208         gc->direction_input  = pca953x_gpio_direction_input;
209         gc->direction_output = pca953x_gpio_direction_output;
210         gc->get = pca953x_gpio_get_value;
211         gc->set = pca953x_gpio_set_value;
212         gc->can_sleep = 1;
213
214         gc->base = chip->gpio_start;
215         gc->ngpio = gpios;
216         gc->label = chip->client->name;
217         gc->dev = &chip->client->dev;
218         gc->owner = THIS_MODULE;
219         gc->names = chip->names;
220 }
221
222 #ifdef CONFIG_GPIO_PCA953X_IRQ
223 static int pca953x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
224 {
225         struct pca953x_chip *chip;
226
227         chip = container_of(gc, struct pca953x_chip, gpio_chip);
228         return chip->irq_base + off;
229 }
230
231 static void pca953x_irq_mask(unsigned int irq)
232 {
233         struct pca953x_chip *chip = get_irq_chip_data(irq);
234
235         chip->irq_mask &= ~(1 << (irq - chip->irq_base));
236 }
237
238 static void pca953x_irq_unmask(unsigned int irq)
239 {
240         struct pca953x_chip *chip = get_irq_chip_data(irq);
241
242         chip->irq_mask |= 1 << (irq - chip->irq_base);
243 }
244
245 static void pca953x_irq_bus_lock(unsigned int irq)
246 {
247         struct pca953x_chip *chip = get_irq_chip_data(irq);
248
249         mutex_lock(&chip->irq_lock);
250 }
251
252 static void pca953x_irq_bus_sync_unlock(unsigned int irq)
253 {
254         struct pca953x_chip *chip = get_irq_chip_data(irq);
255         uint16_t new_irqs;
256         uint16_t level;
257
258         /* Look for any newly setup interrupt */
259         new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
260         new_irqs &= ~chip->reg_direction;
261
262         while (new_irqs) {
263                 level = __ffs(new_irqs);
264                 pca953x_gpio_direction_input(&chip->gpio_chip, level);
265                 new_irqs &= ~(1 << level);
266         }
267
268         mutex_unlock(&chip->irq_lock);
269 }
270
271 static int pca953x_irq_set_type(unsigned int irq, unsigned int type)
272 {
273         struct pca953x_chip *chip = get_irq_chip_data(irq);
274         uint16_t level = irq - chip->irq_base;
275         uint16_t mask = 1 << level;
276
277         if (!(type & IRQ_TYPE_EDGE_BOTH)) {
278                 dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
279                         irq, type);
280                 return -EINVAL;
281         }
282
283         if (type & IRQ_TYPE_EDGE_FALLING)
284                 chip->irq_trig_fall |= mask;
285         else
286                 chip->irq_trig_fall &= ~mask;
287
288         if (type & IRQ_TYPE_EDGE_RISING)
289                 chip->irq_trig_raise |= mask;
290         else
291                 chip->irq_trig_raise &= ~mask;
292
293         return 0;
294 }
295
296 static struct irq_chip pca953x_irq_chip = {
297         .name                   = "pca953x",
298         .mask                   = pca953x_irq_mask,
299         .unmask                 = pca953x_irq_unmask,
300         .bus_lock               = pca953x_irq_bus_lock,
301         .bus_sync_unlock        = pca953x_irq_bus_sync_unlock,
302         .set_type               = pca953x_irq_set_type,
303 };
304
305 static uint16_t pca953x_irq_pending(struct pca953x_chip *chip)
306 {
307         uint16_t cur_stat;
308         uint16_t old_stat;
309         uint16_t pending;
310         uint16_t trigger;
311         int ret;
312
313         ret = pca953x_read_reg(chip, PCA953X_INPUT, &cur_stat);
314         if (ret)
315                 return 0;
316
317         /* Remove output pins from the equation */
318         cur_stat &= chip->reg_direction;
319
320         old_stat = chip->irq_stat;
321         trigger = (cur_stat ^ old_stat) & chip->irq_mask;
322
323         if (!trigger)
324                 return 0;
325
326         chip->irq_stat = cur_stat;
327
328         pending = (old_stat & chip->irq_trig_fall) |
329                   (cur_stat & chip->irq_trig_raise);
330         pending &= trigger;
331
332         return pending;
333 }
334
335 static irqreturn_t pca953x_irq_handler(int irq, void *devid)
336 {
337         struct pca953x_chip *chip = devid;
338         uint16_t pending;
339         uint16_t level;
340
341         pending = pca953x_irq_pending(chip);
342
343         if (!pending)
344                 return IRQ_HANDLED;
345
346         do {
347                 level = __ffs(pending);
348                 generic_handle_irq(level + chip->irq_base);
349
350                 pending &= ~(1 << level);
351         } while (pending);
352
353         return IRQ_HANDLED;
354 }
355
356 static int pca953x_irq_setup(struct pca953x_chip *chip,
357                              const struct i2c_device_id *id)
358 {
359         struct i2c_client *client = chip->client;
360         struct pca953x_platform_data *pdata = client->dev.platform_data;
361         int ret;
362
363         if (pdata->irq_base != -1
364                         && (id->driver_data & PCA953X_INT)) {
365                 int lvl;
366
367                 ret = pca953x_read_reg(chip, PCA953X_INPUT,
368                                        &chip->irq_stat);
369                 if (ret)
370                         goto out_failed;
371
372                 /*
373                  * There is no way to know which GPIO line generated the
374                  * interrupt.  We have to rely on the previous read for
375                  * this purpose.
376                  */
377                 chip->irq_stat &= chip->reg_direction;
378                 chip->irq_base = pdata->irq_base;
379                 mutex_init(&chip->irq_lock);
380
381                 for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) {
382                         int irq = lvl + chip->irq_base;
383
384                         set_irq_chip_data(irq, chip);
385                         set_irq_chip_and_handler(irq, &pca953x_irq_chip,
386                                                  handle_edge_irq);
387 #ifdef CONFIG_ARM
388                         set_irq_flags(irq, IRQF_VALID);
389 #else
390                         set_irq_noprobe(irq);
391 #endif
392                 }
393
394                 ret = request_threaded_irq(client->irq,
395                                            NULL,
396                                            pca953x_irq_handler,
397                                            IRQF_TRIGGER_RISING |
398                                            IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
399                                            dev_name(&client->dev), chip);
400                 if (ret) {
401                         dev_err(&client->dev, "failed to request irq %d\n",
402                                 client->irq);
403                         goto out_failed;
404                 }
405
406                 chip->gpio_chip.to_irq = pca953x_gpio_to_irq;
407         }
408
409         return 0;
410
411 out_failed:
412         chip->irq_base = -1;
413         return ret;
414 }
415
416 static void pca953x_irq_teardown(struct pca953x_chip *chip)
417 {
418         if (chip->irq_base != -1)
419                 free_irq(chip->client->irq, chip);
420 }
421 #else /* CONFIG_GPIO_PCA953X_IRQ */
422 static int pca953x_irq_setup(struct pca953x_chip *chip,
423                              const struct i2c_device_id *id)
424 {
425         struct i2c_client *client = chip->client;
426         struct pca953x_platform_data *pdata = client->dev.platform_data;
427
428         if (pdata->irq_base != -1 && (id->driver_data & PCA953X_INT))
429                 dev_warn(&client->dev, "interrupt support not compiled in\n");
430
431         return 0;
432 }
433
434 static void pca953x_irq_teardown(struct pca953x_chip *chip)
435 {
436 }
437 #endif
438
439 /*
440  * Handlers for alternative sources of platform_data
441  */
442 #ifdef CONFIG_OF_GPIO
443 /*
444  * Translate OpenFirmware node properties into platform_data
445  */
446 static struct pca953x_platform_data *
447 pca953x_get_alt_pdata(struct i2c_client *client)
448 {
449         struct pca953x_platform_data *pdata;
450         struct device_node *node;
451         const uint16_t *val;
452
453         node = client->dev.of_node;
454         if (node == NULL)
455                 return NULL;
456
457         pdata = kzalloc(sizeof(struct pca953x_platform_data), GFP_KERNEL);
458         if (pdata == NULL) {
459                 dev_err(&client->dev, "Unable to allocate platform_data\n");
460                 return NULL;
461         }
462
463         pdata->gpio_base = -1;
464         val = of_get_property(node, "linux,gpio-base", NULL);
465         if (val) {
466                 if (*val < 0)
467                         dev_warn(&client->dev,
468                                  "invalid gpio-base in device tree\n");
469                 else
470                         pdata->gpio_base = *val;
471         }
472
473         val = of_get_property(node, "polarity", NULL);
474         if (val)
475                 pdata->invert = *val;
476
477         return pdata;
478 }
479 #else
480 static struct pca953x_platform_data *
481 pca953x_get_alt_pdata(struct i2c_client *client)
482 {
483         return NULL;
484 }
485 #endif
486
487 static int __devinit pca953x_probe(struct i2c_client *client,
488                                    const struct i2c_device_id *id)
489 {
490         struct pca953x_platform_data *pdata;
491         struct pca953x_chip *chip;
492         int ret;
493
494         chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
495         if (chip == NULL)
496                 return -ENOMEM;
497
498         pdata = client->dev.platform_data;
499         if (pdata == NULL) {
500                 pdata = pca953x_get_alt_pdata(client);
501                 /*
502                  * Unlike normal platform_data, this is allocated
503                  * dynamically and must be freed in the driver
504                  */
505                 chip->dyn_pdata = pdata;
506         }
507
508         if (pdata == NULL) {
509                 dev_dbg(&client->dev, "no platform data\n");
510                 ret = -EINVAL;
511                 goto out_failed;
512         }
513
514         chip->client = client;
515
516         chip->gpio_start = pdata->gpio_base;
517
518         chip->names = pdata->names;
519
520         /* initialize cached registers from their original values.
521          * we can't share this chip with another i2c master.
522          */
523         pca953x_setup_gpio(chip, id->driver_data & PCA953X_GPIOS);
524
525         ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
526         if (ret)
527                 goto out_failed;
528
529         ret = pca953x_read_reg(chip, PCA953X_DIRECTION, &chip->reg_direction);
530         if (ret)
531                 goto out_failed;
532
533         /* set platform specific polarity inversion */
534         ret = pca953x_write_reg(chip, PCA953X_INVERT, pdata->invert);
535         if (ret)
536                 goto out_failed;
537
538         ret = pca953x_irq_setup(chip, id);
539         if (ret)
540                 goto out_failed;
541
542         ret = gpiochip_add(&chip->gpio_chip);
543         if (ret)
544                 goto out_failed;
545
546         if (pdata->setup) {
547                 ret = pdata->setup(client, chip->gpio_chip.base,
548                                 chip->gpio_chip.ngpio, pdata->context);
549                 if (ret < 0)
550                         dev_warn(&client->dev, "setup failed, %d\n", ret);
551         }
552
553         i2c_set_clientdata(client, chip);
554         return 0;
555
556 out_failed:
557         pca953x_irq_teardown(chip);
558         kfree(chip->dyn_pdata);
559         kfree(chip);
560         return ret;
561 }
562
563 static int pca953x_remove(struct i2c_client *client)
564 {
565         struct pca953x_platform_data *pdata = client->dev.platform_data;
566         struct pca953x_chip *chip = i2c_get_clientdata(client);
567         int ret = 0;
568
569         if (pdata->teardown) {
570                 ret = pdata->teardown(client, chip->gpio_chip.base,
571                                 chip->gpio_chip.ngpio, pdata->context);
572                 if (ret < 0) {
573                         dev_err(&client->dev, "%s failed, %d\n",
574                                         "teardown", ret);
575                         return ret;
576                 }
577         }
578
579         ret = gpiochip_remove(&chip->gpio_chip);
580         if (ret) {
581                 dev_err(&client->dev, "%s failed, %d\n",
582                                 "gpiochip_remove()", ret);
583                 return ret;
584         }
585
586         pca953x_irq_teardown(chip);
587         kfree(chip->dyn_pdata);
588         kfree(chip);
589         return 0;
590 }
591
592 static struct i2c_driver pca953x_driver = {
593         .driver = {
594                 .name   = "pca953x",
595         },
596         .probe          = pca953x_probe,
597         .remove         = pca953x_remove,
598         .id_table       = pca953x_id,
599 };
600
601 static int __init pca953x_init(void)
602 {
603         return i2c_add_driver(&pca953x_driver);
604 }
605 /* register after i2c postcore initcall and before
606  * subsys initcalls that may rely on these GPIOs
607  */
608 subsys_initcall(pca953x_init);
609
610 static void __exit pca953x_exit(void)
611 {
612         i2c_del_driver(&pca953x_driver);
613 }
614 module_exit(pca953x_exit);
615
616 MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
617 MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
618 MODULE_LICENSE("GPL");