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path: root/drivers/mfd/htc-i2cpld.c
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-rw-r--r--drivers/mfd/htc-i2cpld.c710
1 files changed, 710 insertions, 0 deletions
diff --git a/drivers/mfd/htc-i2cpld.c b/drivers/mfd/htc-i2cpld.c
new file mode 100644
index 000000000000..37b9fdab4f36
--- /dev/null
+++ b/drivers/mfd/htc-i2cpld.c
@@ -0,0 +1,710 @@
1/*
2 * htc-i2cpld.c
3 * Chip driver for an unknown CPLD chip found on omap850 HTC devices like
4 * the HTC Wizard and HTC Herald.
5 * The cpld is located on the i2c bus and acts as an input/output GPIO
6 * extender.
7 *
8 * Copyright (C) 2009 Cory Maccarrone <darkstar6262@gmail.com>
9 *
10 * Based on work done in the linwizard project
11 * Copyright (C) 2008-2009 Angelo Arrifano <miknix@gmail.com>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
27
28#include <linux/kernel.h>
29#include <linux/init.h>
30#include <linux/module.h>
31#include <linux/interrupt.h>
32#include <linux/platform_device.h>
33#include <linux/i2c.h>
34#include <linux/irq.h>
35#include <linux/spinlock.h>
36#include <linux/htcpld.h>
37#include <linux/gpio.h>
38
39struct htcpld_chip {
40 spinlock_t lock;
41
42 /* chip info */
43 u8 reset;
44 u8 addr;
45 struct device *dev;
46 struct i2c_client *client;
47
48 /* Output details */
49 u8 cache_out;
50 struct gpio_chip chip_out;
51
52 /* Input details */
53 u8 cache_in;
54 struct gpio_chip chip_in;
55
56 u16 irqs_enabled;
57 uint irq_start;
58 int nirqs;
59
60 /*
61 * Work structure to allow for setting values outside of any
62 * possible interrupt context
63 */
64 struct work_struct set_val_work;
65};
66
67struct htcpld_data {
68 /* irq info */
69 u16 irqs_enabled;
70 uint irq_start;
71 int nirqs;
72 uint chained_irq;
73 unsigned int int_reset_gpio_hi;
74 unsigned int int_reset_gpio_lo;
75
76 /* htcpld info */
77 struct htcpld_chip *chip;
78 unsigned int nchips;
79};
80
81/* There does not appear to be a way to proactively mask interrupts
82 * on the htcpld chip itself. So, we simply ignore interrupts that
83 * aren't desired. */
84static void htcpld_mask(unsigned int irq)
85{
86 struct htcpld_chip *chip = get_irq_chip_data(irq);
87 chip->irqs_enabled &= ~(1 << (irq - chip->irq_start));
88 pr_debug("HTCPLD mask %d %04x\n", irq, chip->irqs_enabled);
89}
90static void htcpld_unmask(unsigned int irq)
91{
92 struct htcpld_chip *chip = get_irq_chip_data(irq);
93 chip->irqs_enabled |= 1 << (irq - chip->irq_start);
94 pr_debug("HTCPLD unmask %d %04x\n", irq, chip->irqs_enabled);
95}
96
97static int htcpld_set_type(unsigned int irq, unsigned int flags)
98{
99 struct irq_desc *d = irq_to_desc(irq);
100
101 if (!d) {
102 pr_err("HTCPLD invalid IRQ: %d\n", irq);
103 return -EINVAL;
104 }
105
106 if (flags & ~IRQ_TYPE_SENSE_MASK)
107 return -EINVAL;
108
109 /* We only allow edge triggering */
110 if (flags & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH))
111 return -EINVAL;
112
113 d->status &= ~IRQ_TYPE_SENSE_MASK;
114 d->status |= flags;
115
116 return 0;
117}
118
119static struct irq_chip htcpld_muxed_chip = {
120 .name = "htcpld",
121 .mask = htcpld_mask,
122 .unmask = htcpld_unmask,
123 .set_type = htcpld_set_type,
124};
125
126/* To properly dispatch IRQ events, we need to read from the
127 * chip. This is an I2C action that could possibly sleep
128 * (which is bad in interrupt context) -- so we use a threaded
129 * interrupt handler to get around that.
130 */
131static irqreturn_t htcpld_handler(int irq, void *dev)
132{
133 struct htcpld_data *htcpld = dev;
134 unsigned int i;
135 unsigned long flags;
136 int irqpin;
137 struct irq_desc *desc;
138
139 if (!htcpld) {
140 pr_debug("htcpld is null in ISR\n");
141 return IRQ_HANDLED;
142 }
143
144 /*
145 * For each chip, do a read of the chip and trigger any interrupts
146 * desired. The interrupts will be triggered from LSB to MSB (i.e.
147 * bit 0 first, then bit 1, etc.)
148 *
149 * For chips that have no interrupt range specified, just skip 'em.
150 */
151 for (i = 0; i < htcpld->nchips; i++) {
152 struct htcpld_chip *chip = &htcpld->chip[i];
153 struct i2c_client *client;
154 int val;
155 unsigned long uval, old_val;
156
157 if (!chip) {
158 pr_debug("chip %d is null in ISR\n", i);
159 continue;
160 }
161
162 if (chip->nirqs == 0)
163 continue;
164
165 client = chip->client;
166 if (!client) {
167 pr_debug("client %d is null in ISR\n", i);
168 continue;
169 }
170
171 /* Scan the chip */
172 val = i2c_smbus_read_byte_data(client, chip->cache_out);
173 if (val < 0) {
174 /* Throw a warning and skip this chip */
175 dev_warn(chip->dev, "Unable to read from chip: %d\n",
176 val);
177 continue;
178 }
179
180 uval = (unsigned long)val;
181
182 spin_lock_irqsave(&chip->lock, flags);
183
184 /* Save away the old value so we can compare it */
185 old_val = chip->cache_in;
186
187 /* Write the new value */
188 chip->cache_in = uval;
189
190 spin_unlock_irqrestore(&chip->lock, flags);
191
192 /*
193 * For each bit in the data (starting at bit 0), trigger
194 * associated interrupts.
195 */
196 for (irqpin = 0; irqpin < chip->nirqs; irqpin++) {
197 unsigned oldb, newb;
198 int flags;
199
200 irq = chip->irq_start + irqpin;
201 desc = irq_to_desc(irq);
202 flags = desc->status;
203
204 /* Run the IRQ handler, but only if the bit value
205 * changed, and the proper flags are set */
206 oldb = (old_val >> irqpin) & 1;
207 newb = (uval >> irqpin) & 1;
208
209 if ((!oldb && newb && (flags & IRQ_TYPE_EDGE_RISING)) ||
210 (oldb && !newb &&
211 (flags & IRQ_TYPE_EDGE_FALLING))) {
212 pr_debug("fire IRQ %d\n", irqpin);
213 desc->handle_irq(irq, desc);
214 }
215 }
216 }
217
218 /*
219 * In order to continue receiving interrupts, the int_reset_gpio must
220 * be asserted.
221 */
222 if (htcpld->int_reset_gpio_hi)
223 gpio_set_value(htcpld->int_reset_gpio_hi, 1);
224 if (htcpld->int_reset_gpio_lo)
225 gpio_set_value(htcpld->int_reset_gpio_lo, 0);
226
227 return IRQ_HANDLED;
228}
229
230/*
231 * The GPIO set routines can be called from interrupt context, especially if,
232 * for example they're attached to the led-gpio framework and a trigger is
233 * enabled. As such, we declared work above in the htcpld_chip structure,
234 * and that work is scheduled in the set routine. The kernel can then run
235 * the I2C functions, which will sleep, in process context.
236 */
237void htcpld_chip_set(struct gpio_chip *chip, unsigned offset, int val)
238{
239 struct i2c_client *client;
240 struct htcpld_chip *chip_data;
241 unsigned long flags;
242
243 chip_data = container_of(chip, struct htcpld_chip, chip_out);
244 if (!chip_data)
245 return;
246
247 client = chip_data->client;
248 if (client == NULL)
249 return;
250
251 spin_lock_irqsave(&chip_data->lock, flags);
252 if (val)
253 chip_data->cache_out |= (1 << offset);
254 else
255 chip_data->cache_out &= ~(1 << offset);
256 spin_unlock_irqrestore(&chip_data->lock, flags);
257
258 schedule_work(&(chip_data->set_val_work));
259}
260
261void htcpld_chip_set_ni(struct work_struct *work)
262{
263 struct htcpld_chip *chip_data;
264 struct i2c_client *client;
265
266 chip_data = container_of(work, struct htcpld_chip, set_val_work);
267 client = chip_data->client;
268 i2c_smbus_read_byte_data(client, chip_data->cache_out);
269}
270
271int htcpld_chip_get(struct gpio_chip *chip, unsigned offset)
272{
273 struct htcpld_chip *chip_data;
274 int val = 0;
275 int is_input = 0;
276
277 /* Try out first */
278 chip_data = container_of(chip, struct htcpld_chip, chip_out);
279 if (!chip_data) {
280 /* Try in */
281 is_input = 1;
282 chip_data = container_of(chip, struct htcpld_chip, chip_in);
283 if (!chip_data)
284 return -EINVAL;
285 }
286
287 /* Determine if this is an input or output GPIO */
288 if (!is_input)
289 /* Use the output cache */
290 val = (chip_data->cache_out >> offset) & 1;
291 else
292 /* Use the input cache */
293 val = (chip_data->cache_in >> offset) & 1;
294
295 if (val)
296 return 1;
297 else
298 return 0;
299}
300
301static int htcpld_direction_output(struct gpio_chip *chip,
302 unsigned offset, int value)
303{
304 htcpld_chip_set(chip, offset, value);
305 return 0;
306}
307
308static int htcpld_direction_input(struct gpio_chip *chip,
309 unsigned offset)
310{
311 /*
312 * No-op: this function can only be called on the input chip.
313 * We do however make sure the offset is within range.
314 */
315 return (offset < chip->ngpio) ? 0 : -EINVAL;
316}
317
318int htcpld_chip_to_irq(struct gpio_chip *chip, unsigned offset)
319{
320 struct htcpld_chip *chip_data;
321
322 chip_data = container_of(chip, struct htcpld_chip, chip_in);
323
324 if (offset < chip_data->nirqs)
325 return chip_data->irq_start + offset;
326 else
327 return -EINVAL;
328}
329
330void htcpld_chip_reset(struct i2c_client *client)
331{
332 struct htcpld_chip *chip_data = i2c_get_clientdata(client);
333 if (!chip_data)
334 return;
335
336 i2c_smbus_read_byte_data(
337 client, (chip_data->cache_out = chip_data->reset));
338}
339
340static int __devinit htcpld_setup_chip_irq(
341 struct platform_device *pdev,
342 int chip_index)
343{
344 struct htcpld_data *htcpld;
345 struct device *dev = &pdev->dev;
346 struct htcpld_core_platform_data *pdata;
347 struct htcpld_chip *chip;
348 struct htcpld_chip_platform_data *plat_chip_data;
349 unsigned int irq, irq_end;
350 int ret = 0;
351
352 /* Get the platform and driver data */
353 pdata = dev->platform_data;
354 htcpld = platform_get_drvdata(pdev);
355 chip = &htcpld->chip[chip_index];
356 plat_chip_data = &pdata->chip[chip_index];
357
358 /* Setup irq handlers */
359 irq_end = chip->irq_start + chip->nirqs;
360 for (irq = chip->irq_start; irq < irq_end; irq++) {
361 set_irq_chip(irq, &htcpld_muxed_chip);
362 set_irq_chip_data(irq, chip);
363 set_irq_handler(irq, handle_simple_irq);
364#ifdef CONFIG_ARM
365 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
366#else
367 set_irq_probe(irq);
368#endif
369 }
370
371 return ret;
372}
373
374static int __devinit htcpld_register_chip_i2c(
375 struct platform_device *pdev,
376 int chip_index)
377{
378 struct htcpld_data *htcpld;
379 struct device *dev = &pdev->dev;
380 struct htcpld_core_platform_data *pdata;
381 struct htcpld_chip *chip;
382 struct htcpld_chip_platform_data *plat_chip_data;
383 struct i2c_adapter *adapter;
384 struct i2c_client *client;
385 struct i2c_board_info info;
386
387 /* Get the platform and driver data */
388 pdata = dev->platform_data;
389 htcpld = platform_get_drvdata(pdev);
390 chip = &htcpld->chip[chip_index];
391 plat_chip_data = &pdata->chip[chip_index];
392
393 adapter = i2c_get_adapter(pdata->i2c_adapter_id);
394 if (adapter == NULL) {
395 /* Eek, no such I2C adapter! Bail out. */
396 dev_warn(dev, "Chip at i2c address 0x%x: Invalid i2c adapter %d\n",
397 plat_chip_data->addr, pdata->i2c_adapter_id);
398 return -ENODEV;
399 }
400
401 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
402 dev_warn(dev, "i2c adapter %d non-functional\n",
403 pdata->i2c_adapter_id);
404 return -EINVAL;
405 }
406
407 memset(&info, 0, sizeof(struct i2c_board_info));
408 info.addr = plat_chip_data->addr;
409 strlcpy(info.type, "htcpld-chip", I2C_NAME_SIZE);
410 info.platform_data = chip;
411
412 /* Add the I2C device. This calls the probe() function. */
413 client = i2c_new_device(adapter, &info);
414 if (!client) {
415 /* I2C device registration failed, contineu with the next */
416 dev_warn(dev, "Unable to add I2C device for 0x%x\n",
417 plat_chip_data->addr);
418 return -ENODEV;
419 }
420
421 i2c_set_clientdata(client, chip);
422 snprintf(client->name, I2C_NAME_SIZE, "Chip_0x%d", client->addr);
423 chip->client = client;
424
425 /* Reset the chip */
426 htcpld_chip_reset(client);
427 chip->cache_in = i2c_smbus_read_byte_data(client, chip->cache_out);
428
429 return 0;
430}
431
432static void __devinit htcpld_unregister_chip_i2c(
433 struct platform_device *pdev,
434 int chip_index)
435{
436 struct htcpld_data *htcpld;
437 struct htcpld_chip *chip;
438
439 /* Get the platform and driver data */
440 htcpld = platform_get_drvdata(pdev);
441 chip = &htcpld->chip[chip_index];
442
443 if (chip->client)
444 i2c_unregister_device(chip->client);
445}
446
447static int __devinit htcpld_register_chip_gpio(
448 struct platform_device *pdev,
449 int chip_index)
450{
451 struct htcpld_data *htcpld;
452 struct device *dev = &pdev->dev;
453 struct htcpld_core_platform_data *pdata;
454 struct htcpld_chip *chip;
455 struct htcpld_chip_platform_data *plat_chip_data;
456 struct gpio_chip *gpio_chip;
457 int ret = 0;
458
459 /* Get the platform and driver data */
460 pdata = dev->platform_data;
461 htcpld = platform_get_drvdata(pdev);
462 chip = &htcpld->chip[chip_index];
463 plat_chip_data = &pdata->chip[chip_index];
464
465 /* Setup the GPIO chips */
466 gpio_chip = &(chip->chip_out);
467 gpio_chip->label = "htcpld-out";
468 gpio_chip->dev = dev;
469 gpio_chip->owner = THIS_MODULE;
470 gpio_chip->get = htcpld_chip_get;
471 gpio_chip->set = htcpld_chip_set;
472 gpio_chip->direction_input = NULL;
473 gpio_chip->direction_output = htcpld_direction_output;
474 gpio_chip->base = plat_chip_data->gpio_out_base;
475 gpio_chip->ngpio = plat_chip_data->num_gpios;
476
477 gpio_chip = &(chip->chip_in);
478 gpio_chip->label = "htcpld-in";
479 gpio_chip->dev = dev;
480 gpio_chip->owner = THIS_MODULE;
481 gpio_chip->get = htcpld_chip_get;
482 gpio_chip->set = NULL;
483 gpio_chip->direction_input = htcpld_direction_input;
484 gpio_chip->direction_output = NULL;
485 gpio_chip->to_irq = htcpld_chip_to_irq;
486 gpio_chip->base = plat_chip_data->gpio_in_base;
487 gpio_chip->ngpio = plat_chip_data->num_gpios;
488
489 /* Add the GPIO chips */
490 ret = gpiochip_add(&(chip->chip_out));
491 if (ret) {
492 dev_warn(dev, "Unable to register output GPIOs for 0x%x: %d\n",
493 plat_chip_data->addr, ret);
494 return ret;
495 }
496
497 ret = gpiochip_add(&(chip->chip_in));
498 if (ret) {
499 int error;
500
501 dev_warn(dev, "Unable to register input GPIOs for 0x%x: %d\n",
502 plat_chip_data->addr, ret);
503
504 error = gpiochip_remove(&(chip->chip_out));
505 if (error)
506 dev_warn(dev, "Error while trying to unregister gpio chip: %d\n", error);
507
508 return ret;
509 }
510
511 return 0;
512}
513
514static int __devinit htcpld_setup_chips(struct platform_device *pdev)
515{
516 struct htcpld_data *htcpld;
517 struct device *dev = &pdev->dev;
518 struct htcpld_core_platform_data *pdata;
519 int i;
520
521 /* Get the platform and driver data */
522 pdata = dev->platform_data;
523 htcpld = platform_get_drvdata(pdev);
524
525 /* Setup each chip's output GPIOs */
526 htcpld->nchips = pdata->num_chip;
527 htcpld->chip = kzalloc(sizeof(struct htcpld_chip) * htcpld->nchips,
528 GFP_KERNEL);
529 if (!htcpld->chip) {
530 dev_warn(dev, "Unable to allocate memory for chips\n");
531 return -ENOMEM;
532 }
533
534 /* Add the chips as best we can */
535 for (i = 0; i < htcpld->nchips; i++) {
536 int ret;
537
538 /* Setup the HTCPLD chips */
539 htcpld->chip[i].reset = pdata->chip[i].reset;
540 htcpld->chip[i].cache_out = pdata->chip[i].reset;
541 htcpld->chip[i].cache_in = 0;
542 htcpld->chip[i].dev = dev;
543 htcpld->chip[i].irq_start = pdata->chip[i].irq_base;
544 htcpld->chip[i].nirqs = pdata->chip[i].num_irqs;
545
546 INIT_WORK(&(htcpld->chip[i].set_val_work), &htcpld_chip_set_ni);
547 spin_lock_init(&(htcpld->chip[i].lock));
548
549 /* Setup the interrupts for the chip */
550 if (htcpld->chained_irq) {
551 ret = htcpld_setup_chip_irq(pdev, i);
552 if (ret)
553 continue;
554 }
555
556 /* Register the chip with I2C */
557 ret = htcpld_register_chip_i2c(pdev, i);
558 if (ret)
559 continue;
560
561
562 /* Register the chips with the GPIO subsystem */
563 ret = htcpld_register_chip_gpio(pdev, i);
564 if (ret) {
565 /* Unregister the chip from i2c and continue */
566 htcpld_unregister_chip_i2c(pdev, i);
567 continue;
568 }
569
570 dev_info(dev, "Registered chip at 0x%x\n", pdata->chip[i].addr);
571 }
572
573 return 0;
574}
575
576static int __devinit htcpld_core_probe(struct platform_device *pdev)
577{
578 struct htcpld_data *htcpld;
579 struct device *dev = &pdev->dev;
580 struct htcpld_core_platform_data *pdata;
581 struct resource *res;
582 int ret = 0;
583
584 if (!dev)
585 return -ENODEV;
586
587 pdata = dev->platform_data;
588 if (!pdata) {
589 dev_warn(dev, "Platform data not found for htcpld core!\n");
590 return -ENXIO;
591 }
592
593 htcpld = kzalloc(sizeof(struct htcpld_data), GFP_KERNEL);
594 if (!htcpld)
595 return -ENOMEM;
596
597 /* Find chained irq */
598 ret = -EINVAL;
599 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
600 if (res) {
601 int flags;
602 htcpld->chained_irq = res->start;
603
604 /* Setup the chained interrupt handler */
605 flags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING;
606 ret = request_threaded_irq(htcpld->chained_irq,
607 NULL, htcpld_handler,
608 flags, pdev->name, htcpld);
609 if (ret) {
610 dev_warn(dev, "Unable to setup chained irq handler: %d\n", ret);
611 goto fail;
612 } else
613 device_init_wakeup(dev, 0);
614 }
615
616 /* Set the driver data */
617 platform_set_drvdata(pdev, htcpld);
618
619 /* Setup the htcpld chips */
620 ret = htcpld_setup_chips(pdev);
621 if (ret)
622 goto fail;
623
624 /* Request the GPIO(s) for the int reset and set them up */
625 if (pdata->int_reset_gpio_hi) {
626 ret = gpio_request(pdata->int_reset_gpio_hi, "htcpld-core");
627 if (ret) {
628 /*
629 * If it failed, that sucks, but we can probably
630 * continue on without it.
631 */
632 dev_warn(dev, "Unable to request int_reset_gpio_hi -- interrupts may not work\n");
633 htcpld->int_reset_gpio_hi = 0;
634 } else {
635 htcpld->int_reset_gpio_hi = pdata->int_reset_gpio_hi;
636 gpio_set_value(htcpld->int_reset_gpio_hi, 1);
637 }
638 }
639
640 if (pdata->int_reset_gpio_lo) {
641 ret = gpio_request(pdata->int_reset_gpio_lo, "htcpld-core");
642 if (ret) {
643 /*
644 * If it failed, that sucks, but we can probably
645 * continue on without it.
646 */
647 dev_warn(dev, "Unable to request int_reset_gpio_lo -- interrupts may not work\n");
648 htcpld->int_reset_gpio_lo = 0;
649 } else {
650 htcpld->int_reset_gpio_lo = pdata->int_reset_gpio_lo;
651 gpio_set_value(htcpld->int_reset_gpio_lo, 0);
652 }
653 }
654
655 dev_info(dev, "Initialized successfully\n");
656 return 0;
657
658fail:
659 kfree(htcpld);
660 return ret;
661}
662
663/* The I2C Driver -- used internally */
664static const struct i2c_device_id htcpld_chip_id[] = {
665 { "htcpld-chip", 0 },
666 { }
667};
668MODULE_DEVICE_TABLE(i2c, htcpld_chip_id);
669
670
671static struct i2c_driver htcpld_chip_driver = {
672 .driver = {
673 .name = "htcpld-chip",
674 },
675 .id_table = htcpld_chip_id,
676};
677
678/* The Core Driver */
679static struct platform_driver htcpld_core_driver = {
680 .driver = {
681 .name = "i2c-htcpld",
682 },
683};
684
685static int __init htcpld_core_init(void)
686{
687 int ret;
688
689 /* Register the I2C Chip driver */
690 ret = i2c_add_driver(&htcpld_chip_driver);
691 if (ret)
692 return ret;
693
694 /* Probe for our chips */
695 return platform_driver_probe(&htcpld_core_driver, htcpld_core_probe);
696}
697
698static void __exit htcpld_core_exit(void)
699{
700 i2c_del_driver(&htcpld_chip_driver);
701 platform_driver_unregister(&htcpld_core_driver);
702}
703
704module_init(htcpld_core_init);
705module_exit(htcpld_core_exit);
706
707MODULE_AUTHOR("Cory Maccarrone <darkstar6262@gmail.com>");
708MODULE_DESCRIPTION("I2C HTC PLD Driver");
709MODULE_LICENSE("GPL");
710
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-25 03:21:06 -0500