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
;
62 * Work structure to allow for setting values outside of any
63 * possible interrupt context
65 struct work_struct set_val_work
;
74 unsigned int int_reset_gpio_hi
;
75 unsigned int int_reset_gpio_lo
;
78 struct htcpld_chip
*chip
;
82 /* There does not appear to be a way to proactively mask interrupts
83 * on the htcpld chip itself. So, we simply ignore interrupts that
85 static void htcpld_mask(struct irq_data
*data
)
87 struct htcpld_chip
*chip
= irq_data_get_irq_chip_data(data
);
88 chip
->irqs_enabled
&= ~(1 << (data
->irq
- chip
->irq_start
));
89 pr_debug("HTCPLD mask %d %04x\n", data
->irq
, chip
->irqs_enabled
);
91 static void htcpld_unmask(struct irq_data
*data
)
93 struct htcpld_chip
*chip
= irq_data_get_irq_chip_data(data
);
94 chip
->irqs_enabled
|= 1 << (data
->irq
- chip
->irq_start
);
95 pr_debug("HTCPLD unmask %d %04x\n", data
->irq
, chip
->irqs_enabled
);
98 static int htcpld_set_type(struct irq_data
*data
, unsigned int flags
)
100 struct irq_desc
*d
= irq_to_desc(data
->irq
);
103 pr_err("HTCPLD invalid IRQ: %d\n", data
->irq
);
107 if (flags
& ~IRQ_TYPE_SENSE_MASK
)
110 /* We only allow edge triggering */
111 if (flags
& (IRQ_TYPE_LEVEL_LOW
|IRQ_TYPE_LEVEL_HIGH
))
114 d
->status
&= ~IRQ_TYPE_SENSE_MASK
;
120 static struct irq_chip htcpld_muxed_chip
= {
122 .irq_mask
= htcpld_mask
,
123 .irq_unmask
= htcpld_unmask
,
124 .irq_set_type
= htcpld_set_type
,
127 /* To properly dispatch IRQ events, we need to read from the
128 * chip. This is an I2C action that could possibly sleep
129 * (which is bad in interrupt context) -- so we use a threaded
130 * interrupt handler to get around that.
132 static irqreturn_t
htcpld_handler(int irq
, void *dev
)
134 struct htcpld_data
*htcpld
= dev
;
138 struct irq_desc
*desc
;
141 pr_debug("htcpld is null in ISR\n");
146 * For each chip, do a read of the chip and trigger any interrupts
147 * desired. The interrupts will be triggered from LSB to MSB (i.e.
148 * bit 0 first, then bit 1, etc.)
150 * For chips that have no interrupt range specified, just skip 'em.
152 for (i
= 0; i
< htcpld
->nchips
; i
++) {
153 struct htcpld_chip
*chip
= &htcpld
->chip
[i
];
154 struct i2c_client
*client
;
156 unsigned long uval
, old_val
;
159 pr_debug("chip %d is null in ISR\n", i
);
163 if (chip
->nirqs
== 0)
166 client
= chip
->client
;
168 pr_debug("client %d is null in ISR\n", i
);
173 val
= i2c_smbus_read_byte_data(client
, chip
->cache_out
);
175 /* Throw a warning and skip this chip */
176 dev_warn(chip
->dev
, "Unable to read from chip: %d\n",
181 uval
= (unsigned long)val
;
183 spin_lock_irqsave(&chip
->lock
, flags
);
185 /* Save away the old value so we can compare it */
186 old_val
= chip
->cache_in
;
188 /* Write the new value */
189 chip
->cache_in
= uval
;
191 spin_unlock_irqrestore(&chip
->lock
, flags
);
194 * For each bit in the data (starting at bit 0), trigger
195 * associated interrupts.
197 for (irqpin
= 0; irqpin
< chip
->nirqs
; irqpin
++) {
201 irq
= chip
->irq_start
+ irqpin
;
202 desc
= irq_to_desc(irq
);
203 flags
= desc
->status
;
205 /* Run the IRQ handler, but only if the bit value
206 * changed, and the proper flags are set */
207 oldb
= (old_val
>> irqpin
) & 1;
208 newb
= (uval
>> irqpin
) & 1;
210 if ((!oldb
&& newb
&& (flags
& IRQ_TYPE_EDGE_RISING
)) ||
212 (flags
& IRQ_TYPE_EDGE_FALLING
))) {
213 pr_debug("fire IRQ %d\n", irqpin
);
214 desc
->handle_irq(irq
, desc
);
220 * In order to continue receiving interrupts, the int_reset_gpio must
223 if (htcpld
->int_reset_gpio_hi
)
224 gpio_set_value(htcpld
->int_reset_gpio_hi
, 1);
225 if (htcpld
->int_reset_gpio_lo
)
226 gpio_set_value(htcpld
->int_reset_gpio_lo
, 0);
232 * The GPIO set routines can be called from interrupt context, especially if,
233 * for example they're attached to the led-gpio framework and a trigger is
234 * enabled. As such, we declared work above in the htcpld_chip structure,
235 * and that work is scheduled in the set routine. The kernel can then run
236 * the I2C functions, which will sleep, in process context.
238 static void htcpld_chip_set(struct gpio_chip
*chip
, unsigned offset
, int val
)
240 struct i2c_client
*client
;
241 struct htcpld_chip
*chip_data
;
244 chip_data
= container_of(chip
, struct htcpld_chip
, chip_out
);
248 client
= chip_data
->client
;
252 spin_lock_irqsave(&chip_data
->lock
, flags
);
254 chip_data
->cache_out
|= (1 << offset
);
256 chip_data
->cache_out
&= ~(1 << offset
);
257 spin_unlock_irqrestore(&chip_data
->lock
, flags
);
259 schedule_work(&(chip_data
->set_val_work
));
262 static void htcpld_chip_set_ni(struct work_struct
*work
)
264 struct htcpld_chip
*chip_data
;
265 struct i2c_client
*client
;
267 chip_data
= container_of(work
, struct htcpld_chip
, set_val_work
);
268 client
= chip_data
->client
;
269 i2c_smbus_read_byte_data(client
, chip_data
->cache_out
);
272 static int htcpld_chip_get(struct gpio_chip
*chip
, unsigned offset
)
274 struct htcpld_chip
*chip_data
;
279 chip_data
= container_of(chip
, struct htcpld_chip
, chip_out
);
283 chip_data
= container_of(chip
, struct htcpld_chip
, chip_in
);
288 /* Determine if this is an input or output GPIO */
290 /* Use the output cache */
291 val
= (chip_data
->cache_out
>> offset
) & 1;
293 /* Use the input cache */
294 val
= (chip_data
->cache_in
>> offset
) & 1;
302 static int htcpld_direction_output(struct gpio_chip
*chip
,
303 unsigned offset
, int value
)
305 htcpld_chip_set(chip
, offset
, value
);
309 static int htcpld_direction_input(struct gpio_chip
*chip
,
313 * No-op: this function can only be called on the input chip.
314 * We do however make sure the offset is within range.
316 return (offset
< chip
->ngpio
) ? 0 : -EINVAL
;
319 static int htcpld_chip_to_irq(struct gpio_chip
*chip
, unsigned offset
)
321 struct htcpld_chip
*chip_data
;
323 chip_data
= container_of(chip
, struct htcpld_chip
, chip_in
);
325 if (offset
< chip_data
->nirqs
)
326 return chip_data
->irq_start
+ offset
;
331 static void htcpld_chip_reset(struct i2c_client
*client
)
333 struct htcpld_chip
*chip_data
= i2c_get_clientdata(client
);
337 i2c_smbus_read_byte_data(
338 client
, (chip_data
->cache_out
= chip_data
->reset
));
341 static int __devinit
htcpld_setup_chip_irq(
342 struct platform_device
*pdev
,
345 struct htcpld_data
*htcpld
;
346 struct device
*dev
= &pdev
->dev
;
347 struct htcpld_core_platform_data
*pdata
;
348 struct htcpld_chip
*chip
;
349 struct htcpld_chip_platform_data
*plat_chip_data
;
350 unsigned int irq
, irq_end
;
353 /* Get the platform and driver data */
354 pdata
= dev
->platform_data
;
355 htcpld
= platform_get_drvdata(pdev
);
356 chip
= &htcpld
->chip
[chip_index
];
357 plat_chip_data
= &pdata
->chip
[chip_index
];
359 /* Setup irq handlers */
360 irq_end
= chip
->irq_start
+ chip
->nirqs
;
361 for (irq
= chip
->irq_start
; irq
< irq_end
; irq
++) {
362 set_irq_chip(irq
, &htcpld_muxed_chip
);
363 set_irq_chip_data(irq
, chip
);
364 set_irq_handler(irq
, handle_simple_irq
);
366 set_irq_flags(irq
, IRQF_VALID
| IRQF_PROBE
);
375 static int __devinit
htcpld_register_chip_i2c(
376 struct platform_device
*pdev
,
379 struct htcpld_data
*htcpld
;
380 struct device
*dev
= &pdev
->dev
;
381 struct htcpld_core_platform_data
*pdata
;
382 struct htcpld_chip
*chip
;
383 struct htcpld_chip_platform_data
*plat_chip_data
;
384 struct i2c_adapter
*adapter
;
385 struct i2c_client
*client
;
386 struct i2c_board_info info
;
388 /* Get the platform and driver data */
389 pdata
= dev
->platform_data
;
390 htcpld
= platform_get_drvdata(pdev
);
391 chip
= &htcpld
->chip
[chip_index
];
392 plat_chip_data
= &pdata
->chip
[chip_index
];
394 adapter
= i2c_get_adapter(pdata
->i2c_adapter_id
);
395 if (adapter
== NULL
) {
396 /* Eek, no such I2C adapter! Bail out. */
397 dev_warn(dev
, "Chip at i2c address 0x%x: Invalid i2c adapter %d\n",
398 plat_chip_data
->addr
, pdata
->i2c_adapter_id
);
402 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_READ_BYTE_DATA
)) {
403 dev_warn(dev
, "i2c adapter %d non-functional\n",
404 pdata
->i2c_adapter_id
);
408 memset(&info
, 0, sizeof(struct i2c_board_info
));
409 info
.addr
= plat_chip_data
->addr
;
410 strlcpy(info
.type
, "htcpld-chip", I2C_NAME_SIZE
);
411 info
.platform_data
= chip
;
413 /* Add the I2C device. This calls the probe() function. */
414 client
= i2c_new_device(adapter
, &info
);
416 /* I2C device registration failed, contineu with the next */
417 dev_warn(dev
, "Unable to add I2C device for 0x%x\n",
418 plat_chip_data
->addr
);
422 i2c_set_clientdata(client
, chip
);
423 snprintf(client
->name
, I2C_NAME_SIZE
, "Chip_0x%d", client
->addr
);
424 chip
->client
= client
;
427 htcpld_chip_reset(client
);
428 chip
->cache_in
= i2c_smbus_read_byte_data(client
, chip
->cache_out
);
433 static void __devinit
htcpld_unregister_chip_i2c(
434 struct platform_device
*pdev
,
437 struct htcpld_data
*htcpld
;
438 struct htcpld_chip
*chip
;
440 /* Get the platform and driver data */
441 htcpld
= platform_get_drvdata(pdev
);
442 chip
= &htcpld
->chip
[chip_index
];
445 i2c_unregister_device(chip
->client
);
448 static int __devinit
htcpld_register_chip_gpio(
449 struct platform_device
*pdev
,
452 struct htcpld_data
*htcpld
;
453 struct device
*dev
= &pdev
->dev
;
454 struct htcpld_core_platform_data
*pdata
;
455 struct htcpld_chip
*chip
;
456 struct htcpld_chip_platform_data
*plat_chip_data
;
457 struct gpio_chip
*gpio_chip
;
460 /* Get the platform and driver data */
461 pdata
= dev
->platform_data
;
462 htcpld
= platform_get_drvdata(pdev
);
463 chip
= &htcpld
->chip
[chip_index
];
464 plat_chip_data
= &pdata
->chip
[chip_index
];
466 /* Setup the GPIO chips */
467 gpio_chip
= &(chip
->chip_out
);
468 gpio_chip
->label
= "htcpld-out";
469 gpio_chip
->dev
= dev
;
470 gpio_chip
->owner
= THIS_MODULE
;
471 gpio_chip
->get
= htcpld_chip_get
;
472 gpio_chip
->set
= htcpld_chip_set
;
473 gpio_chip
->direction_input
= NULL
;
474 gpio_chip
->direction_output
= htcpld_direction_output
;
475 gpio_chip
->base
= plat_chip_data
->gpio_out_base
;
476 gpio_chip
->ngpio
= plat_chip_data
->num_gpios
;
478 gpio_chip
= &(chip
->chip_in
);
479 gpio_chip
->label
= "htcpld-in";
480 gpio_chip
->dev
= dev
;
481 gpio_chip
->owner
= THIS_MODULE
;
482 gpio_chip
->get
= htcpld_chip_get
;
483 gpio_chip
->set
= NULL
;
484 gpio_chip
->direction_input
= htcpld_direction_input
;
485 gpio_chip
->direction_output
= NULL
;
486 gpio_chip
->to_irq
= htcpld_chip_to_irq
;
487 gpio_chip
->base
= plat_chip_data
->gpio_in_base
;
488 gpio_chip
->ngpio
= plat_chip_data
->num_gpios
;
490 /* Add the GPIO chips */
491 ret
= gpiochip_add(&(chip
->chip_out
));
493 dev_warn(dev
, "Unable to register output GPIOs for 0x%x: %d\n",
494 plat_chip_data
->addr
, ret
);
498 ret
= gpiochip_add(&(chip
->chip_in
));
502 dev_warn(dev
, "Unable to register input GPIOs for 0x%x: %d\n",
503 plat_chip_data
->addr
, ret
);
505 error
= gpiochip_remove(&(chip
->chip_out
));
507 dev_warn(dev
, "Error while trying to unregister gpio chip: %d\n", error
);
515 static int __devinit
htcpld_setup_chips(struct platform_device
*pdev
)
517 struct htcpld_data
*htcpld
;
518 struct device
*dev
= &pdev
->dev
;
519 struct htcpld_core_platform_data
*pdata
;
522 /* Get the platform and driver data */
523 pdata
= dev
->platform_data
;
524 htcpld
= platform_get_drvdata(pdev
);
526 /* Setup each chip's output GPIOs */
527 htcpld
->nchips
= pdata
->num_chip
;
528 htcpld
->chip
= kzalloc(sizeof(struct htcpld_chip
) * htcpld
->nchips
,
531 dev_warn(dev
, "Unable to allocate memory for chips\n");
535 /* Add the chips as best we can */
536 for (i
= 0; i
< htcpld
->nchips
; i
++) {
539 /* Setup the HTCPLD chips */
540 htcpld
->chip
[i
].reset
= pdata
->chip
[i
].reset
;
541 htcpld
->chip
[i
].cache_out
= pdata
->chip
[i
].reset
;
542 htcpld
->chip
[i
].cache_in
= 0;
543 htcpld
->chip
[i
].dev
= dev
;
544 htcpld
->chip
[i
].irq_start
= pdata
->chip
[i
].irq_base
;
545 htcpld
->chip
[i
].nirqs
= pdata
->chip
[i
].num_irqs
;
547 INIT_WORK(&(htcpld
->chip
[i
].set_val_work
), &htcpld_chip_set_ni
);
548 spin_lock_init(&(htcpld
->chip
[i
].lock
));
550 /* Setup the interrupts for the chip */
551 if (htcpld
->chained_irq
) {
552 ret
= htcpld_setup_chip_irq(pdev
, i
);
557 /* Register the chip with I2C */
558 ret
= htcpld_register_chip_i2c(pdev
, i
);
563 /* Register the chips with the GPIO subsystem */
564 ret
= htcpld_register_chip_gpio(pdev
, i
);
566 /* Unregister the chip from i2c and continue */
567 htcpld_unregister_chip_i2c(pdev
, i
);
571 dev_info(dev
, "Registered chip at 0x%x\n", pdata
->chip
[i
].addr
);
577 static int __devinit
htcpld_core_probe(struct platform_device
*pdev
)
579 struct htcpld_data
*htcpld
;
580 struct device
*dev
= &pdev
->dev
;
581 struct htcpld_core_platform_data
*pdata
;
582 struct resource
*res
;
588 pdata
= dev
->platform_data
;
590 dev_warn(dev
, "Platform data not found for htcpld core!\n");
594 htcpld
= kzalloc(sizeof(struct htcpld_data
), GFP_KERNEL
);
598 /* Find chained irq */
600 res
= platform_get_resource(pdev
, IORESOURCE_IRQ
, 0);
603 htcpld
->chained_irq
= res
->start
;
605 /* Setup the chained interrupt handler */
606 flags
= IRQF_TRIGGER_FALLING
| IRQF_TRIGGER_RISING
;
607 ret
= request_threaded_irq(htcpld
->chained_irq
,
608 NULL
, htcpld_handler
,
609 flags
, pdev
->name
, htcpld
);
611 dev_warn(dev
, "Unable to setup chained irq handler: %d\n", ret
);
614 device_init_wakeup(dev
, 0);
617 /* Set the driver data */
618 platform_set_drvdata(pdev
, htcpld
);
620 /* Setup the htcpld chips */
621 ret
= htcpld_setup_chips(pdev
);
625 /* Request the GPIO(s) for the int reset and set them up */
626 if (pdata
->int_reset_gpio_hi
) {
627 ret
= gpio_request(pdata
->int_reset_gpio_hi
, "htcpld-core");
630 * If it failed, that sucks, but we can probably
631 * continue on without it.
633 dev_warn(dev
, "Unable to request int_reset_gpio_hi -- interrupts may not work\n");
634 htcpld
->int_reset_gpio_hi
= 0;
636 htcpld
->int_reset_gpio_hi
= pdata
->int_reset_gpio_hi
;
637 gpio_set_value(htcpld
->int_reset_gpio_hi
, 1);
641 if (pdata
->int_reset_gpio_lo
) {
642 ret
= gpio_request(pdata
->int_reset_gpio_lo
, "htcpld-core");
645 * If it failed, that sucks, but we can probably
646 * continue on without it.
648 dev_warn(dev
, "Unable to request int_reset_gpio_lo -- interrupts may not work\n");
649 htcpld
->int_reset_gpio_lo
= 0;
651 htcpld
->int_reset_gpio_lo
= pdata
->int_reset_gpio_lo
;
652 gpio_set_value(htcpld
->int_reset_gpio_lo
, 0);
656 dev_info(dev
, "Initialized successfully\n");
664 /* The I2C Driver -- used internally */
665 static const struct i2c_device_id htcpld_chip_id
[] = {
666 { "htcpld-chip", 0 },
669 MODULE_DEVICE_TABLE(i2c
, htcpld_chip_id
);
672 static struct i2c_driver htcpld_chip_driver
= {
674 .name
= "htcpld-chip",
676 .id_table
= htcpld_chip_id
,
679 /* The Core Driver */
680 static struct platform_driver htcpld_core_driver
= {
682 .name
= "i2c-htcpld",
686 static int __init
htcpld_core_init(void)
690 /* Register the I2C Chip driver */
691 ret
= i2c_add_driver(&htcpld_chip_driver
);
695 /* Probe for our chips */
696 return platform_driver_probe(&htcpld_core_driver
, htcpld_core_probe
);
699 static void __exit
htcpld_core_exit(void)
701 i2c_del_driver(&htcpld_chip_driver
);
702 platform_driver_unregister(&htcpld_core_driver
);
705 module_init(htcpld_core_init
);
706 module_exit(htcpld_core_exit
);
708 MODULE_AUTHOR("Cory Maccarrone <darkstar6262@gmail.com>");
709 MODULE_DESCRIPTION("I2C HTC PLD Driver");
710 MODULE_LICENSE("GPL");