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
8 * Copyright (C) 2009 Cory Maccarrone <darkstar6262@gmail.com>
10 * Based on work done in the linwizard project
11 * Copyright (C) 2008-2009 Angelo Arrifano <miknix@gmail.com>
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.
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.
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.
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>
46 struct i2c_client *client;
50 struct gpio_chip chip_out;
54 struct gpio_chip chip_in;
61 * Work structure to allow for setting values outside of any
62 * possible interrupt context
64 struct work_struct set_val_work;
73 unsigned int int_reset_gpio_hi;
74 unsigned int int_reset_gpio_lo;
77 struct htcpld_chip *chip;
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
84 static void htcpld_mask(unsigned int irq)
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);
90 static void htcpld_unmask(unsigned int irq)
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);
97 static int htcpld_set_type(unsigned int irq, unsigned int flags)
99 struct irq_desc *d = irq_to_desc(irq);
102 pr_err("HTCPLD invalid IRQ: %d\n", irq);
106 if (flags & ~IRQ_TYPE_SENSE_MASK)
109 /* We only allow edge triggering */
110 if (flags & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH))
113 d->status &= ~IRQ_TYPE_SENSE_MASK;
119 static struct irq_chip htcpld_muxed_chip = {
122 .unmask = htcpld_unmask,
123 .set_type = htcpld_set_type,
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.
131 static irqreturn_t htcpld_handler(int irq, void *dev)
133 struct htcpld_data *htcpld = dev;
137 struct irq_desc *desc;
140 pr_debug("htcpld is null in ISR\n");
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.)
149 * For chips that have no interrupt range specified, just skip 'em.
151 for (i = 0; i < htcpld->nchips; i++) {
152 struct htcpld_chip *chip = &htcpld->chip[i];
153 struct i2c_client *client;
155 unsigned long uval, old_val;
158 pr_debug("chip %d is null in ISR\n", i);
162 if (chip->nirqs == 0)
165 client = chip->client;
167 pr_debug("client %d is null in ISR\n", i);
172 val = i2c_smbus_read_byte_data(client, chip->cache_out);
174 /* Throw a warning and skip this chip */
175 dev_warn(chip->dev, "Unable to read from chip: %d\n",
180 uval = (unsigned long)val;
182 spin_lock_irqsave(&chip->lock, flags);
184 /* Save away the old value so we can compare it */
185 old_val = chip->cache_in;
187 /* Write the new value */
188 chip->cache_in = uval;
190 spin_unlock_irqrestore(&chip->lock, flags);
193 * For each bit in the data (starting at bit 0), trigger
194 * associated interrupts.
196 for (irqpin = 0; irqpin < chip->nirqs; irqpin++) {
200 irq = chip->irq_start + irqpin;
201 desc = irq_to_desc(irq);
202 flags = desc->status;
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;
209 if ((!oldb && newb && (flags & IRQ_TYPE_EDGE_RISING)) ||
211 (flags & IRQ_TYPE_EDGE_FALLING))) {
212 pr_debug("fire IRQ %d\n", irqpin);
213 desc->handle_irq(irq, desc);
219 * In order to continue receiving interrupts, the int_reset_gpio must
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);
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.
237 void htcpld_chip_set(struct gpio_chip *chip, unsigned offset, int val)
239 struct i2c_client *client;
240 struct htcpld_chip *chip_data;
243 chip_data = container_of(chip, struct htcpld_chip, chip_out);
247 client = chip_data->client;
251 spin_lock_irqsave(&chip_data->lock, flags);
253 chip_data->cache_out |= (1 << offset);
255 chip_data->cache_out &= ~(1 << offset);
256 spin_unlock_irqrestore(&chip_data->lock, flags);
258 schedule_work(&(chip_data->set_val_work));
261 void htcpld_chip_set_ni(struct work_struct *work)
263 struct htcpld_chip *chip_data;
264 struct i2c_client *client;
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);
271 int htcpld_chip_get(struct gpio_chip *chip, unsigned offset)
273 struct htcpld_chip *chip_data;
278 chip_data = container_of(chip, struct htcpld_chip, chip_out);
282 chip_data = container_of(chip, struct htcpld_chip, chip_in);
287 /* Determine if this is an input or output GPIO */
289 /* Use the output cache */
290 val = (chip_data->cache_out >> offset) & 1;
292 /* Use the input cache */
293 val = (chip_data->cache_in >> offset) & 1;
301 static int htcpld_direction_output(struct gpio_chip *chip,
302 unsigned offset, int value)
304 htcpld_chip_set(chip, offset, value);
308 static int htcpld_direction_input(struct gpio_chip *chip,
312 * No-op: this function can only be called on the input chip.
313 * We do however make sure the offset is within range.
315 return (offset < chip->ngpio) ? 0 : -EINVAL;
318 int htcpld_chip_to_irq(struct gpio_chip *chip, unsigned offset)
320 struct htcpld_chip *chip_data;
322 chip_data = container_of(chip, struct htcpld_chip, chip_in);
324 if (offset < chip_data->nirqs)
325 return chip_data->irq_start + offset;
330 void htcpld_chip_reset(struct i2c_client *client)
332 struct htcpld_chip *chip_data = i2c_get_clientdata(client);
336 i2c_smbus_read_byte_data(
337 client, (chip_data->cache_out = chip_data->reset));
340 static int __devinit htcpld_setup_chip_irq(
341 struct platform_device *pdev,
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;
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];
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);
365 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
374 static int __devinit htcpld_register_chip_i2c(
375 struct platform_device *pdev,
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;
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];
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);
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);
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;
412 /* Add the I2C device. This calls the probe() function. */
413 client = i2c_new_device(adapter, &info);
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);
421 i2c_set_clientdata(client, chip);
422 snprintf(client->name, I2C_NAME_SIZE, "Chip_0x%d", client->addr);
423 chip->client = client;
426 htcpld_chip_reset(client);
427 chip->cache_in = i2c_smbus_read_byte_data(client, chip->cache_out);
432 static void __devinit htcpld_unregister_chip_i2c(
433 struct platform_device *pdev,
436 struct htcpld_data *htcpld;
437 struct htcpld_chip *chip;
439 /* Get the platform and driver data */
440 htcpld = platform_get_drvdata(pdev);
441 chip = &htcpld->chip[chip_index];
444 i2c_unregister_device(chip->client);
447 static int __devinit htcpld_register_chip_gpio(
448 struct platform_device *pdev,
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;
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];
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;
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;
489 /* Add the GPIO chips */
490 ret = gpiochip_add(&(chip->chip_out));
492 dev_warn(dev, "Unable to register output GPIOs for 0x%x: %d\n",
493 plat_chip_data->addr, ret);
497 ret = gpiochip_add(&(chip->chip_in));
501 dev_warn(dev, "Unable to register input GPIOs for 0x%x: %d\n",
502 plat_chip_data->addr, ret);
504 error = gpiochip_remove(&(chip->chip_out));
506 dev_warn(dev, "Error while trying to unregister gpio chip: %d\n", error);
514 static int __devinit htcpld_setup_chips(struct platform_device *pdev)
516 struct htcpld_data *htcpld;
517 struct device *dev = &pdev->dev;
518 struct htcpld_core_platform_data *pdata;
521 /* Get the platform and driver data */
522 pdata = dev->platform_data;
523 htcpld = platform_get_drvdata(pdev);
525 /* Setup each chip's output GPIOs */
526 htcpld->nchips = pdata->num_chip;
527 htcpld->chip = kzalloc(sizeof(struct htcpld_chip) * htcpld->nchips,
530 dev_warn(dev, "Unable to allocate memory for chips\n");
534 /* Add the chips as best we can */
535 for (i = 0; i < htcpld->nchips; i++) {
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;
546 INIT_WORK(&(htcpld->chip[i].set_val_work), &htcpld_chip_set_ni);
547 spin_lock_init(&(htcpld->chip[i].lock));
549 /* Setup the interrupts for the chip */
550 if (htcpld->chained_irq) {
551 ret = htcpld_setup_chip_irq(pdev, i);
556 /* Register the chip with I2C */
557 ret = htcpld_register_chip_i2c(pdev, i);
562 /* Register the chips with the GPIO subsystem */
563 ret = htcpld_register_chip_gpio(pdev, i);
565 /* Unregister the chip from i2c and continue */
566 htcpld_unregister_chip_i2c(pdev, i);
570 dev_info(dev, "Registered chip at 0x%x\n", pdata->chip[i].addr);
576 static int __devinit htcpld_core_probe(struct platform_device *pdev)
578 struct htcpld_data *htcpld;
579 struct device *dev = &pdev->dev;
580 struct htcpld_core_platform_data *pdata;
581 struct resource *res;
587 pdata = dev->platform_data;
589 dev_warn(dev, "Platform data not found for htcpld core!\n");
593 htcpld = kzalloc(sizeof(struct htcpld_data), GFP_KERNEL);
597 /* Find chained irq */
599 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
602 htcpld->chained_irq = res->start;
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);
610 dev_warn(dev, "Unable to setup chained irq handler: %d\n", ret);
613 device_init_wakeup(dev, 0);
616 /* Set the driver data */
617 platform_set_drvdata(pdev, htcpld);
619 /* Setup the htcpld chips */
620 ret = htcpld_setup_chips(pdev);
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");
629 * If it failed, that sucks, but we can probably
630 * continue on without it.
632 dev_warn(dev, "Unable to request int_reset_gpio_hi -- interrupts may not work\n");
633 htcpld->int_reset_gpio_hi = 0;
635 htcpld->int_reset_gpio_hi = pdata->int_reset_gpio_hi;
636 gpio_set_value(htcpld->int_reset_gpio_hi, 1);
640 if (pdata->int_reset_gpio_lo) {
641 ret = gpio_request(pdata->int_reset_gpio_lo, "htcpld-core");
644 * If it failed, that sucks, but we can probably
645 * continue on without it.
647 dev_warn(dev, "Unable to request int_reset_gpio_lo -- interrupts may not work\n");
648 htcpld->int_reset_gpio_lo = 0;
650 htcpld->int_reset_gpio_lo = pdata->int_reset_gpio_lo;
651 gpio_set_value(htcpld->int_reset_gpio_lo, 0);
655 dev_info(dev, "Initialized successfully\n");
663 /* The I2C Driver -- used internally */
664 static const struct i2c_device_id htcpld_chip_id[] = {
665 { "htcpld-chip", 0 },
668 MODULE_DEVICE_TABLE(i2c, htcpld_chip_id);
671 static struct i2c_driver htcpld_chip_driver = {
673 .name = "htcpld-chip",
675 .id_table = htcpld_chip_id,
678 /* The Core Driver */
679 static struct platform_driver htcpld_core_driver = {
681 .name = "i2c-htcpld",
685 static int __init htcpld_core_init(void)
689 /* Register the I2C Chip driver */
690 ret = i2c_add_driver(&htcpld_chip_driver);
694 /* Probe for our chips */
695 return platform_driver_probe(&htcpld_core_driver, htcpld_core_probe);
698 static void __exit htcpld_core_exit(void)
700 i2c_del_driver(&htcpld_chip_driver);
701 platform_driver_unregister(&htcpld_core_driver);
704 module_init(htcpld_core_init);
705 module_exit(htcpld_core_exit);
707 MODULE_AUTHOR("Cory Maccarrone <darkstar6262@gmail.com>");
708 MODULE_DESCRIPTION("I2C HTC PLD Driver");
709 MODULE_LICENSE("GPL");