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;
233 chip_data = container_of(chip, struct htcpld_chip, chip_out);
237 client = chip_data->client;
241 spin_lock_irqsave(&chip_data->lock, flags);
243 chip_data->cache_out |= (1 << offset);
245 chip_data->cache_out &= ~(1 << offset);
246 spin_unlock_irqrestore(&chip_data->lock, flags);
248 schedule_work(&(chip_data->set_val_work));
251 static void htcpld_chip_set_ni(struct work_struct *work)
253 struct htcpld_chip *chip_data;
254 struct i2c_client *client;
256 chip_data = container_of(work, struct htcpld_chip, set_val_work);
257 client = chip_data->client;
258 i2c_smbus_read_byte_data(client, chip_data->cache_out);
261 static int htcpld_chip_get(struct gpio_chip *chip, unsigned offset)
263 struct htcpld_chip *chip_data;
268 chip_data = container_of(chip, struct htcpld_chip, chip_out);
272 chip_data = container_of(chip, struct htcpld_chip, chip_in);
277 /* Determine if this is an input or output GPIO */
279 /* Use the output cache */
280 val = (chip_data->cache_out >> offset) & 1;
282 /* Use the input cache */
283 val = (chip_data->cache_in >> offset) & 1;
291 static int htcpld_direction_output(struct gpio_chip *chip,
292 unsigned offset, int value)
294 htcpld_chip_set(chip, offset, value);
298 static int htcpld_direction_input(struct gpio_chip *chip,
302 * No-op: this function can only be called on the input chip.
303 * We do however make sure the offset is within range.
305 return (offset < chip->ngpio) ? 0 : -EINVAL;
308 static int htcpld_chip_to_irq(struct gpio_chip *chip, unsigned offset)
310 struct htcpld_chip *chip_data;
312 chip_data = container_of(chip, struct htcpld_chip, chip_in);
314 if (offset < chip_data->nirqs)
315 return chip_data->irq_start + offset;
320 static void htcpld_chip_reset(struct i2c_client *client)
322 struct htcpld_chip *chip_data = i2c_get_clientdata(client);
326 i2c_smbus_read_byte_data(
327 client, (chip_data->cache_out = chip_data->reset));
330 static int htcpld_setup_chip_irq(
331 struct platform_device *pdev,
334 struct htcpld_data *htcpld;
335 struct htcpld_chip *chip;
336 unsigned int irq, irq_end;
339 /* Get the platform and driver data */
340 htcpld = platform_get_drvdata(pdev);
341 chip = &htcpld->chip[chip_index];
343 /* Setup irq handlers */
344 irq_end = chip->irq_start + chip->nirqs;
345 for (irq = chip->irq_start; irq < irq_end; irq++) {
346 irq_set_chip_and_handler(irq, &htcpld_muxed_chip,
348 irq_set_chip_data(irq, chip);
350 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
359 static int htcpld_register_chip_i2c(
360 struct platform_device *pdev,
363 struct htcpld_data *htcpld;
364 struct device *dev = &pdev->dev;
365 struct htcpld_core_platform_data *pdata;
366 struct htcpld_chip *chip;
367 struct htcpld_chip_platform_data *plat_chip_data;
368 struct i2c_adapter *adapter;
369 struct i2c_client *client;
370 struct i2c_board_info info;
372 /* Get the platform and driver data */
373 pdata = dev_get_platdata(dev);
374 htcpld = platform_get_drvdata(pdev);
375 chip = &htcpld->chip[chip_index];
376 plat_chip_data = &pdata->chip[chip_index];
378 adapter = i2c_get_adapter(pdata->i2c_adapter_id);
379 if (adapter == NULL) {
380 /* Eek, no such I2C adapter! Bail out. */
381 dev_warn(dev, "Chip at i2c address 0x%x: Invalid i2c adapter %d\n",
382 plat_chip_data->addr, pdata->i2c_adapter_id);
386 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
387 dev_warn(dev, "i2c adapter %d non-functional\n",
388 pdata->i2c_adapter_id);
392 memset(&info, 0, sizeof(struct i2c_board_info));
393 info.addr = plat_chip_data->addr;
394 strlcpy(info.type, "htcpld-chip", I2C_NAME_SIZE);
395 info.platform_data = chip;
397 /* Add the I2C device. This calls the probe() function. */
398 client = i2c_new_device(adapter, &info);
400 /* I2C device registration failed, contineu with the next */
401 dev_warn(dev, "Unable to add I2C device for 0x%x\n",
402 plat_chip_data->addr);
406 i2c_set_clientdata(client, chip);
407 snprintf(client->name, I2C_NAME_SIZE, "Chip_0x%x", client->addr);
408 chip->client = client;
411 htcpld_chip_reset(client);
412 chip->cache_in = i2c_smbus_read_byte_data(client, chip->cache_out);
417 static void htcpld_unregister_chip_i2c(
418 struct platform_device *pdev,
421 struct htcpld_data *htcpld;
422 struct htcpld_chip *chip;
424 /* Get the platform and driver data */
425 htcpld = platform_get_drvdata(pdev);
426 chip = &htcpld->chip[chip_index];
429 i2c_unregister_device(chip->client);
432 static int htcpld_register_chip_gpio(
433 struct platform_device *pdev,
436 struct htcpld_data *htcpld;
437 struct device *dev = &pdev->dev;
438 struct htcpld_core_platform_data *pdata;
439 struct htcpld_chip *chip;
440 struct htcpld_chip_platform_data *plat_chip_data;
441 struct gpio_chip *gpio_chip;
444 /* Get the platform and driver data */
445 pdata = dev_get_platdata(dev);
446 htcpld = platform_get_drvdata(pdev);
447 chip = &htcpld->chip[chip_index];
448 plat_chip_data = &pdata->chip[chip_index];
450 /* Setup the GPIO chips */
451 gpio_chip = &(chip->chip_out);
452 gpio_chip->label = "htcpld-out";
453 gpio_chip->dev = dev;
454 gpio_chip->owner = THIS_MODULE;
455 gpio_chip->get = htcpld_chip_get;
456 gpio_chip->set = htcpld_chip_set;
457 gpio_chip->direction_input = NULL;
458 gpio_chip->direction_output = htcpld_direction_output;
459 gpio_chip->base = plat_chip_data->gpio_out_base;
460 gpio_chip->ngpio = plat_chip_data->num_gpios;
462 gpio_chip = &(chip->chip_in);
463 gpio_chip->label = "htcpld-in";
464 gpio_chip->dev = dev;
465 gpio_chip->owner = THIS_MODULE;
466 gpio_chip->get = htcpld_chip_get;
467 gpio_chip->set = NULL;
468 gpio_chip->direction_input = htcpld_direction_input;
469 gpio_chip->direction_output = NULL;
470 gpio_chip->to_irq = htcpld_chip_to_irq;
471 gpio_chip->base = plat_chip_data->gpio_in_base;
472 gpio_chip->ngpio = plat_chip_data->num_gpios;
474 /* Add the GPIO chips */
475 ret = gpiochip_add(&(chip->chip_out));
477 dev_warn(dev, "Unable to register output GPIOs for 0x%x: %d\n",
478 plat_chip_data->addr, ret);
482 ret = gpiochip_add(&(chip->chip_in));
486 dev_warn(dev, "Unable to register input GPIOs for 0x%x: %d\n",
487 plat_chip_data->addr, ret);
489 error = gpiochip_remove(&(chip->chip_out));
491 dev_warn(dev, "Error while trying to unregister gpio chip: %d\n", error);
499 static int htcpld_setup_chips(struct platform_device *pdev)
501 struct htcpld_data *htcpld;
502 struct device *dev = &pdev->dev;
503 struct htcpld_core_platform_data *pdata;
506 /* Get the platform and driver data */
507 pdata = dev_get_platdata(dev);
508 htcpld = platform_get_drvdata(pdev);
510 /* Setup each chip's output GPIOs */
511 htcpld->nchips = pdata->num_chip;
512 htcpld->chip = devm_kzalloc(dev, sizeof(struct htcpld_chip) * htcpld->nchips,
515 dev_warn(dev, "Unable to allocate memory for chips\n");
519 /* Add the chips as best we can */
520 for (i = 0; i < htcpld->nchips; i++) {
523 /* Setup the HTCPLD chips */
524 htcpld->chip[i].reset = pdata->chip[i].reset;
525 htcpld->chip[i].cache_out = pdata->chip[i].reset;
526 htcpld->chip[i].cache_in = 0;
527 htcpld->chip[i].dev = dev;
528 htcpld->chip[i].irq_start = pdata->chip[i].irq_base;
529 htcpld->chip[i].nirqs = pdata->chip[i].num_irqs;
531 INIT_WORK(&(htcpld->chip[i].set_val_work), &htcpld_chip_set_ni);
532 spin_lock_init(&(htcpld->chip[i].lock));
534 /* Setup the interrupts for the chip */
535 if (htcpld->chained_irq) {
536 ret = htcpld_setup_chip_irq(pdev, i);
541 /* Register the chip with I2C */
542 ret = htcpld_register_chip_i2c(pdev, i);
547 /* Register the chips with the GPIO subsystem */
548 ret = htcpld_register_chip_gpio(pdev, i);
550 /* Unregister the chip from i2c and continue */
551 htcpld_unregister_chip_i2c(pdev, i);
555 dev_info(dev, "Registered chip at 0x%x\n", pdata->chip[i].addr);
561 static int htcpld_core_probe(struct platform_device *pdev)
563 struct htcpld_data *htcpld;
564 struct device *dev = &pdev->dev;
565 struct htcpld_core_platform_data *pdata;
566 struct resource *res;
572 pdata = dev_get_platdata(dev);
574 dev_warn(dev, "Platform data not found for htcpld core!\n");
578 htcpld = devm_kzalloc(dev, sizeof(struct htcpld_data), GFP_KERNEL);
582 /* Find chained irq */
583 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
586 htcpld->chained_irq = res->start;
588 /* Setup the chained interrupt handler */
589 flags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING;
590 ret = request_threaded_irq(htcpld->chained_irq,
591 NULL, htcpld_handler,
592 flags, pdev->name, htcpld);
594 dev_warn(dev, "Unable to setup chained irq handler: %d\n", ret);
597 device_init_wakeup(dev, 0);
600 /* Set the driver data */
601 platform_set_drvdata(pdev, htcpld);
603 /* Setup the htcpld chips */
604 ret = htcpld_setup_chips(pdev);
608 /* Request the GPIO(s) for the int reset and set them up */
609 if (pdata->int_reset_gpio_hi) {
610 ret = gpio_request(pdata->int_reset_gpio_hi, "htcpld-core");
613 * If it failed, that sucks, but we can probably
614 * continue on without it.
616 dev_warn(dev, "Unable to request int_reset_gpio_hi -- interrupts may not work\n");
617 htcpld->int_reset_gpio_hi = 0;
619 htcpld->int_reset_gpio_hi = pdata->int_reset_gpio_hi;
620 gpio_set_value(htcpld->int_reset_gpio_hi, 1);
624 if (pdata->int_reset_gpio_lo) {
625 ret = gpio_request(pdata->int_reset_gpio_lo, "htcpld-core");
628 * If it failed, that sucks, but we can probably
629 * continue on without it.
631 dev_warn(dev, "Unable to request int_reset_gpio_lo -- interrupts may not work\n");
632 htcpld->int_reset_gpio_lo = 0;
634 htcpld->int_reset_gpio_lo = pdata->int_reset_gpio_lo;
635 gpio_set_value(htcpld->int_reset_gpio_lo, 0);
639 dev_info(dev, "Initialized successfully\n");
643 /* The I2C Driver -- used internally */
644 static const struct i2c_device_id htcpld_chip_id[] = {
645 { "htcpld-chip", 0 },
648 MODULE_DEVICE_TABLE(i2c, htcpld_chip_id);
651 static struct i2c_driver htcpld_chip_driver = {
653 .name = "htcpld-chip",
655 .id_table = htcpld_chip_id,
658 /* The Core Driver */
659 static struct platform_driver htcpld_core_driver = {
661 .name = "i2c-htcpld",
665 static int __init htcpld_core_init(void)
669 /* Register the I2C Chip driver */
670 ret = i2c_add_driver(&htcpld_chip_driver);
674 /* Probe for our chips */
675 return platform_driver_probe(&htcpld_core_driver, htcpld_core_probe);
678 static void __exit htcpld_core_exit(void)
680 i2c_del_driver(&htcpld_chip_driver);
681 platform_driver_unregister(&htcpld_core_driver);
684 module_init(htcpld_core_init);
685 module_exit(htcpld_core_exit);
687 MODULE_AUTHOR("Cory Maccarrone <darkstar6262@gmail.com>");
688 MODULE_DESCRIPTION("I2C HTC PLD Driver");
689 MODULE_LICENSE("GPL");