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>
38 #include <linux/slab.h>
47 struct i2c_client *client;
51 struct gpio_chip chip_out;
55 struct gpio_chip chip_in;
61 unsigned int flow_type;
63 * Work structure to allow for setting values outside of any
64 * possible interrupt context
66 struct work_struct set_val_work;
75 unsigned int int_reset_gpio_hi;
76 unsigned int int_reset_gpio_lo;
79 struct htcpld_chip *chip;
83 /* There does not appear to be a way to proactively mask interrupts
84 * on the htcpld chip itself. So, we simply ignore interrupts that
86 static void htcpld_mask(struct irq_data *data)
88 struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
89 chip->irqs_enabled &= ~(1 << (data->irq - chip->irq_start));
90 pr_debug("HTCPLD mask %d %04x\n", data->irq, chip->irqs_enabled);
92 static void htcpld_unmask(struct irq_data *data)
94 struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
95 chip->irqs_enabled |= 1 << (data->irq - chip->irq_start);
96 pr_debug("HTCPLD unmask %d %04x\n", data->irq, chip->irqs_enabled);
99 static int htcpld_set_type(struct irq_data *data, unsigned int flags)
101 struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
103 if (flags & ~IRQ_TYPE_SENSE_MASK)
106 /* We only allow edge triggering */
107 if (flags & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH))
110 chip->flow_type = flags;
114 static struct irq_chip htcpld_muxed_chip = {
116 .irq_mask = htcpld_mask,
117 .irq_unmask = htcpld_unmask,
118 .irq_set_type = htcpld_set_type,
121 /* To properly dispatch IRQ events, we need to read from the
122 * chip. This is an I2C action that could possibly sleep
123 * (which is bad in interrupt context) -- so we use a threaded
124 * interrupt handler to get around that.
126 static irqreturn_t htcpld_handler(int irq, void *dev)
128 struct htcpld_data *htcpld = dev;
134 pr_debug("htcpld is null in ISR\n");
139 * For each chip, do a read of the chip and trigger any interrupts
140 * desired. The interrupts will be triggered from LSB to MSB (i.e.
141 * bit 0 first, then bit 1, etc.)
143 * For chips that have no interrupt range specified, just skip 'em.
145 for (i = 0; i < htcpld->nchips; i++) {
146 struct htcpld_chip *chip = &htcpld->chip[i];
147 struct i2c_client *client;
149 unsigned long uval, old_val;
152 pr_debug("chip %d is null in ISR\n", i);
156 if (chip->nirqs == 0)
159 client = chip->client;
161 pr_debug("client %d is null in ISR\n", i);
166 val = i2c_smbus_read_byte_data(client, chip->cache_out);
168 /* Throw a warning and skip this chip */
169 dev_warn(chip->dev, "Unable to read from chip: %d\n",
174 uval = (unsigned long)val;
176 spin_lock_irqsave(&chip->lock, flags);
178 /* Save away the old value so we can compare it */
179 old_val = chip->cache_in;
181 /* Write the new value */
182 chip->cache_in = uval;
184 spin_unlock_irqrestore(&chip->lock, flags);
187 * For each bit in the data (starting at bit 0), trigger
188 * associated interrupts.
190 for (irqpin = 0; irqpin < chip->nirqs; irqpin++) {
191 unsigned oldb, newb, type = chip->flow_type;
193 irq = chip->irq_start + irqpin;
195 /* Run the IRQ handler, but only if the bit value
196 * changed, and the proper flags are set */
197 oldb = (old_val >> irqpin) & 1;
198 newb = (uval >> irqpin) & 1;
200 if ((!oldb && newb && (type & IRQ_TYPE_EDGE_RISING)) ||
201 (oldb && !newb && (type & IRQ_TYPE_EDGE_FALLING))) {
202 pr_debug("fire IRQ %d\n", irqpin);
203 generic_handle_irq(irq);
209 * In order to continue receiving interrupts, the int_reset_gpio must
212 if (htcpld->int_reset_gpio_hi)
213 gpio_set_value(htcpld->int_reset_gpio_hi, 1);
214 if (htcpld->int_reset_gpio_lo)
215 gpio_set_value(htcpld->int_reset_gpio_lo, 0);
221 * The GPIO set routines can be called from interrupt context, especially if,
222 * for example they're attached to the led-gpio framework and a trigger is
223 * enabled. As such, we declared work above in the htcpld_chip structure,
224 * and that work is scheduled in the set routine. The kernel can then run
225 * the I2C functions, which will sleep, in process context.
227 static void htcpld_chip_set(struct gpio_chip *chip, unsigned offset, int val)
229 struct i2c_client *client;
230 struct htcpld_chip *chip_data =
231 container_of(chip, struct htcpld_chip, chip_out);
234 client = chip_data->client;
238 spin_lock_irqsave(&chip_data->lock, flags);
240 chip_data->cache_out |= (1 << offset);
242 chip_data->cache_out &= ~(1 << offset);
243 spin_unlock_irqrestore(&chip_data->lock, flags);
245 schedule_work(&(chip_data->set_val_work));
248 static void htcpld_chip_set_ni(struct work_struct *work)
250 struct htcpld_chip *chip_data;
251 struct i2c_client *client;
253 chip_data = container_of(work, struct htcpld_chip, set_val_work);
254 client = chip_data->client;
255 i2c_smbus_read_byte_data(client, chip_data->cache_out);
258 static int htcpld_chip_get(struct gpio_chip *chip, unsigned offset)
260 struct htcpld_chip *chip_data;
263 if (!strncmp(chip->label, "htcpld-out", 10)) {
264 chip_data = container_of(chip, struct htcpld_chip, chip_out);
265 cache = chip_data->cache_out;
266 } else if (!strncmp(chip->label, "htcpld-in", 9)) {
267 chip_data = container_of(chip, struct htcpld_chip, chip_in);
268 cache = chip_data->cache_in;
272 return (cache >> offset) & 1;
275 static int htcpld_direction_output(struct gpio_chip *chip,
276 unsigned offset, int value)
278 htcpld_chip_set(chip, offset, value);
282 static int htcpld_direction_input(struct gpio_chip *chip,
286 * No-op: this function can only be called on the input chip.
287 * We do however make sure the offset is within range.
289 return (offset < chip->ngpio) ? 0 : -EINVAL;
292 static int htcpld_chip_to_irq(struct gpio_chip *chip, unsigned offset)
294 struct htcpld_chip *chip_data;
296 chip_data = container_of(chip, struct htcpld_chip, chip_in);
298 if (offset < chip_data->nirqs)
299 return chip_data->irq_start + offset;
304 static void htcpld_chip_reset(struct i2c_client *client)
306 struct htcpld_chip *chip_data = i2c_get_clientdata(client);
310 i2c_smbus_read_byte_data(
311 client, (chip_data->cache_out = chip_data->reset));
314 static int htcpld_setup_chip_irq(
315 struct platform_device *pdev,
318 struct htcpld_data *htcpld;
319 struct htcpld_chip *chip;
320 unsigned int irq, irq_end;
323 /* Get the platform and driver data */
324 htcpld = platform_get_drvdata(pdev);
325 chip = &htcpld->chip[chip_index];
327 /* Setup irq handlers */
328 irq_end = chip->irq_start + chip->nirqs;
329 for (irq = chip->irq_start; irq < irq_end; irq++) {
330 irq_set_chip_and_handler(irq, &htcpld_muxed_chip,
332 irq_set_chip_data(irq, chip);
334 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
343 static int htcpld_register_chip_i2c(
344 struct platform_device *pdev,
347 struct htcpld_data *htcpld;
348 struct device *dev = &pdev->dev;
349 struct htcpld_core_platform_data *pdata;
350 struct htcpld_chip *chip;
351 struct htcpld_chip_platform_data *plat_chip_data;
352 struct i2c_adapter *adapter;
353 struct i2c_client *client;
354 struct i2c_board_info info;
356 /* Get the platform and driver data */
357 pdata = dev_get_platdata(dev);
358 htcpld = platform_get_drvdata(pdev);
359 chip = &htcpld->chip[chip_index];
360 plat_chip_data = &pdata->chip[chip_index];
362 adapter = i2c_get_adapter(pdata->i2c_adapter_id);
364 /* Eek, no such I2C adapter! Bail out. */
365 dev_warn(dev, "Chip at i2c address 0x%x: Invalid i2c adapter %d\n",
366 plat_chip_data->addr, pdata->i2c_adapter_id);
370 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
371 dev_warn(dev, "i2c adapter %d non-functional\n",
372 pdata->i2c_adapter_id);
376 memset(&info, 0, sizeof(struct i2c_board_info));
377 info.addr = plat_chip_data->addr;
378 strlcpy(info.type, "htcpld-chip", I2C_NAME_SIZE);
379 info.platform_data = chip;
381 /* Add the I2C device. This calls the probe() function. */
382 client = i2c_new_device(adapter, &info);
384 /* I2C device registration failed, contineu with the next */
385 dev_warn(dev, "Unable to add I2C device for 0x%x\n",
386 plat_chip_data->addr);
390 i2c_set_clientdata(client, chip);
391 snprintf(client->name, I2C_NAME_SIZE, "Chip_0x%x", client->addr);
392 chip->client = client;
395 htcpld_chip_reset(client);
396 chip->cache_in = i2c_smbus_read_byte_data(client, chip->cache_out);
401 static void htcpld_unregister_chip_i2c(
402 struct platform_device *pdev,
405 struct htcpld_data *htcpld;
406 struct htcpld_chip *chip;
408 /* Get the platform and driver data */
409 htcpld = platform_get_drvdata(pdev);
410 chip = &htcpld->chip[chip_index];
413 i2c_unregister_device(chip->client);
416 static int htcpld_register_chip_gpio(
417 struct platform_device *pdev,
420 struct htcpld_data *htcpld;
421 struct device *dev = &pdev->dev;
422 struct htcpld_core_platform_data *pdata;
423 struct htcpld_chip *chip;
424 struct htcpld_chip_platform_data *plat_chip_data;
425 struct gpio_chip *gpio_chip;
428 /* Get the platform and driver data */
429 pdata = dev_get_platdata(dev);
430 htcpld = platform_get_drvdata(pdev);
431 chip = &htcpld->chip[chip_index];
432 plat_chip_data = &pdata->chip[chip_index];
434 /* Setup the GPIO chips */
435 gpio_chip = &(chip->chip_out);
436 gpio_chip->label = "htcpld-out";
437 gpio_chip->dev = dev;
438 gpio_chip->owner = THIS_MODULE;
439 gpio_chip->get = htcpld_chip_get;
440 gpio_chip->set = htcpld_chip_set;
441 gpio_chip->direction_input = NULL;
442 gpio_chip->direction_output = htcpld_direction_output;
443 gpio_chip->base = plat_chip_data->gpio_out_base;
444 gpio_chip->ngpio = plat_chip_data->num_gpios;
446 gpio_chip = &(chip->chip_in);
447 gpio_chip->label = "htcpld-in";
448 gpio_chip->dev = dev;
449 gpio_chip->owner = THIS_MODULE;
450 gpio_chip->get = htcpld_chip_get;
451 gpio_chip->set = NULL;
452 gpio_chip->direction_input = htcpld_direction_input;
453 gpio_chip->direction_output = NULL;
454 gpio_chip->to_irq = htcpld_chip_to_irq;
455 gpio_chip->base = plat_chip_data->gpio_in_base;
456 gpio_chip->ngpio = plat_chip_data->num_gpios;
458 /* Add the GPIO chips */
459 ret = gpiochip_add(&(chip->chip_out));
461 dev_warn(dev, "Unable to register output GPIOs for 0x%x: %d\n",
462 plat_chip_data->addr, ret);
466 ret = gpiochip_add(&(chip->chip_in));
468 dev_warn(dev, "Unable to register input GPIOs for 0x%x: %d\n",
469 plat_chip_data->addr, ret);
470 gpiochip_remove(&(chip->chip_out));
477 static int htcpld_setup_chips(struct platform_device *pdev)
479 struct htcpld_data *htcpld;
480 struct device *dev = &pdev->dev;
481 struct htcpld_core_platform_data *pdata;
484 /* Get the platform and driver data */
485 pdata = dev_get_platdata(dev);
486 htcpld = platform_get_drvdata(pdev);
488 /* Setup each chip's output GPIOs */
489 htcpld->nchips = pdata->num_chip;
490 htcpld->chip = devm_kzalloc(dev, sizeof(struct htcpld_chip) * htcpld->nchips,
493 dev_warn(dev, "Unable to allocate memory for chips\n");
497 /* Add the chips as best we can */
498 for (i = 0; i < htcpld->nchips; i++) {
501 /* Setup the HTCPLD chips */
502 htcpld->chip[i].reset = pdata->chip[i].reset;
503 htcpld->chip[i].cache_out = pdata->chip[i].reset;
504 htcpld->chip[i].cache_in = 0;
505 htcpld->chip[i].dev = dev;
506 htcpld->chip[i].irq_start = pdata->chip[i].irq_base;
507 htcpld->chip[i].nirqs = pdata->chip[i].num_irqs;
509 INIT_WORK(&(htcpld->chip[i].set_val_work), &htcpld_chip_set_ni);
510 spin_lock_init(&(htcpld->chip[i].lock));
512 /* Setup the interrupts for the chip */
513 if (htcpld->chained_irq) {
514 ret = htcpld_setup_chip_irq(pdev, i);
519 /* Register the chip with I2C */
520 ret = htcpld_register_chip_i2c(pdev, i);
525 /* Register the chips with the GPIO subsystem */
526 ret = htcpld_register_chip_gpio(pdev, i);
528 /* Unregister the chip from i2c and continue */
529 htcpld_unregister_chip_i2c(pdev, i);
533 dev_info(dev, "Registered chip at 0x%x\n", pdata->chip[i].addr);
539 static int htcpld_core_probe(struct platform_device *pdev)
541 struct htcpld_data *htcpld;
542 struct device *dev = &pdev->dev;
543 struct htcpld_core_platform_data *pdata;
544 struct resource *res;
550 pdata = dev_get_platdata(dev);
552 dev_warn(dev, "Platform data not found for htcpld core!\n");
556 htcpld = devm_kzalloc(dev, sizeof(struct htcpld_data), GFP_KERNEL);
560 /* Find chained irq */
561 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
564 htcpld->chained_irq = res->start;
566 /* Setup the chained interrupt handler */
567 flags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
569 ret = request_threaded_irq(htcpld->chained_irq,
570 NULL, htcpld_handler,
571 flags, pdev->name, htcpld);
573 dev_warn(dev, "Unable to setup chained irq handler: %d\n", ret);
576 device_init_wakeup(dev, 0);
579 /* Set the driver data */
580 platform_set_drvdata(pdev, htcpld);
582 /* Setup the htcpld chips */
583 ret = htcpld_setup_chips(pdev);
587 /* Request the GPIO(s) for the int reset and set them up */
588 if (pdata->int_reset_gpio_hi) {
589 ret = gpio_request(pdata->int_reset_gpio_hi, "htcpld-core");
592 * If it failed, that sucks, but we can probably
593 * continue on without it.
595 dev_warn(dev, "Unable to request int_reset_gpio_hi -- interrupts may not work\n");
596 htcpld->int_reset_gpio_hi = 0;
598 htcpld->int_reset_gpio_hi = pdata->int_reset_gpio_hi;
599 gpio_set_value(htcpld->int_reset_gpio_hi, 1);
603 if (pdata->int_reset_gpio_lo) {
604 ret = gpio_request(pdata->int_reset_gpio_lo, "htcpld-core");
607 * If it failed, that sucks, but we can probably
608 * continue on without it.
610 dev_warn(dev, "Unable to request int_reset_gpio_lo -- interrupts may not work\n");
611 htcpld->int_reset_gpio_lo = 0;
613 htcpld->int_reset_gpio_lo = pdata->int_reset_gpio_lo;
614 gpio_set_value(htcpld->int_reset_gpio_lo, 0);
618 dev_info(dev, "Initialized successfully\n");
622 /* The I2C Driver -- used internally */
623 static const struct i2c_device_id htcpld_chip_id[] = {
624 { "htcpld-chip", 0 },
627 MODULE_DEVICE_TABLE(i2c, htcpld_chip_id);
630 static struct i2c_driver htcpld_chip_driver = {
632 .name = "htcpld-chip",
634 .id_table = htcpld_chip_id,
637 /* The Core Driver */
638 static struct platform_driver htcpld_core_driver = {
640 .name = "i2c-htcpld",
644 static int __init htcpld_core_init(void)
648 /* Register the I2C Chip driver */
649 ret = i2c_add_driver(&htcpld_chip_driver);
653 /* Probe for our chips */
654 return platform_driver_probe(&htcpld_core_driver, htcpld_core_probe);
657 static void __exit htcpld_core_exit(void)
659 i2c_del_driver(&htcpld_chip_driver);
660 platform_driver_unregister(&htcpld_core_driver);
663 module_init(htcpld_core_init);
664 module_exit(htcpld_core_exit);
666 MODULE_AUTHOR("Cory Maccarrone <darkstar6262@gmail.com>");
667 MODULE_DESCRIPTION("I2C HTC PLD Driver");
668 MODULE_LICENSE("GPL");