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 device
*dev
= &pdev
->dev
;
336 struct htcpld_core_platform_data
*pdata
;
337 struct htcpld_chip
*chip
;
338 struct htcpld_chip_platform_data
*plat_chip_data
;
339 unsigned int irq
, irq_end
;
342 /* Get the platform and driver data */
343 pdata
= dev
->platform_data
;
344 htcpld
= platform_get_drvdata(pdev
);
345 chip
= &htcpld
->chip
[chip_index
];
346 plat_chip_data
= &pdata
->chip
[chip_index
];
348 /* Setup irq handlers */
349 irq_end
= chip
->irq_start
+ chip
->nirqs
;
350 for (irq
= chip
->irq_start
; irq
< irq_end
; irq
++) {
351 irq_set_chip_and_handler(irq
, &htcpld_muxed_chip
,
353 irq_set_chip_data(irq
, chip
);
355 set_irq_flags(irq
, IRQF_VALID
| IRQF_PROBE
);
364 static int htcpld_register_chip_i2c(
365 struct platform_device
*pdev
,
368 struct htcpld_data
*htcpld
;
369 struct device
*dev
= &pdev
->dev
;
370 struct htcpld_core_platform_data
*pdata
;
371 struct htcpld_chip
*chip
;
372 struct htcpld_chip_platform_data
*plat_chip_data
;
373 struct i2c_adapter
*adapter
;
374 struct i2c_client
*client
;
375 struct i2c_board_info info
;
377 /* Get the platform and driver data */
378 pdata
= dev
->platform_data
;
379 htcpld
= platform_get_drvdata(pdev
);
380 chip
= &htcpld
->chip
[chip_index
];
381 plat_chip_data
= &pdata
->chip
[chip_index
];
383 adapter
= i2c_get_adapter(pdata
->i2c_adapter_id
);
384 if (adapter
== NULL
) {
385 /* Eek, no such I2C adapter! Bail out. */
386 dev_warn(dev
, "Chip at i2c address 0x%x: Invalid i2c adapter %d\n",
387 plat_chip_data
->addr
, pdata
->i2c_adapter_id
);
391 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_READ_BYTE_DATA
)) {
392 dev_warn(dev
, "i2c adapter %d non-functional\n",
393 pdata
->i2c_adapter_id
);
397 memset(&info
, 0, sizeof(struct i2c_board_info
));
398 info
.addr
= plat_chip_data
->addr
;
399 strlcpy(info
.type
, "htcpld-chip", I2C_NAME_SIZE
);
400 info
.platform_data
= chip
;
402 /* Add the I2C device. This calls the probe() function. */
403 client
= i2c_new_device(adapter
, &info
);
405 /* I2C device registration failed, contineu with the next */
406 dev_warn(dev
, "Unable to add I2C device for 0x%x\n",
407 plat_chip_data
->addr
);
411 i2c_set_clientdata(client
, chip
);
412 snprintf(client
->name
, I2C_NAME_SIZE
, "Chip_0x%d", client
->addr
);
413 chip
->client
= client
;
416 htcpld_chip_reset(client
);
417 chip
->cache_in
= i2c_smbus_read_byte_data(client
, chip
->cache_out
);
422 static void htcpld_unregister_chip_i2c(
423 struct platform_device
*pdev
,
426 struct htcpld_data
*htcpld
;
427 struct htcpld_chip
*chip
;
429 /* Get the platform and driver data */
430 htcpld
= platform_get_drvdata(pdev
);
431 chip
= &htcpld
->chip
[chip_index
];
434 i2c_unregister_device(chip
->client
);
437 static int htcpld_register_chip_gpio(
438 struct platform_device
*pdev
,
441 struct htcpld_data
*htcpld
;
442 struct device
*dev
= &pdev
->dev
;
443 struct htcpld_core_platform_data
*pdata
;
444 struct htcpld_chip
*chip
;
445 struct htcpld_chip_platform_data
*plat_chip_data
;
446 struct gpio_chip
*gpio_chip
;
449 /* Get the platform and driver data */
450 pdata
= dev
->platform_data
;
451 htcpld
= platform_get_drvdata(pdev
);
452 chip
= &htcpld
->chip
[chip_index
];
453 plat_chip_data
= &pdata
->chip
[chip_index
];
455 /* Setup the GPIO chips */
456 gpio_chip
= &(chip
->chip_out
);
457 gpio_chip
->label
= "htcpld-out";
458 gpio_chip
->dev
= dev
;
459 gpio_chip
->owner
= THIS_MODULE
;
460 gpio_chip
->get
= htcpld_chip_get
;
461 gpio_chip
->set
= htcpld_chip_set
;
462 gpio_chip
->direction_input
= NULL
;
463 gpio_chip
->direction_output
= htcpld_direction_output
;
464 gpio_chip
->base
= plat_chip_data
->gpio_out_base
;
465 gpio_chip
->ngpio
= plat_chip_data
->num_gpios
;
467 gpio_chip
= &(chip
->chip_in
);
468 gpio_chip
->label
= "htcpld-in";
469 gpio_chip
->dev
= dev
;
470 gpio_chip
->owner
= THIS_MODULE
;
471 gpio_chip
->get
= htcpld_chip_get
;
472 gpio_chip
->set
= NULL
;
473 gpio_chip
->direction_input
= htcpld_direction_input
;
474 gpio_chip
->direction_output
= NULL
;
475 gpio_chip
->to_irq
= htcpld_chip_to_irq
;
476 gpio_chip
->base
= plat_chip_data
->gpio_in_base
;
477 gpio_chip
->ngpio
= plat_chip_data
->num_gpios
;
479 /* Add the GPIO chips */
480 ret
= gpiochip_add(&(chip
->chip_out
));
482 dev_warn(dev
, "Unable to register output GPIOs for 0x%x: %d\n",
483 plat_chip_data
->addr
, ret
);
487 ret
= gpiochip_add(&(chip
->chip_in
));
491 dev_warn(dev
, "Unable to register input GPIOs for 0x%x: %d\n",
492 plat_chip_data
->addr
, ret
);
494 error
= gpiochip_remove(&(chip
->chip_out
));
496 dev_warn(dev
, "Error while trying to unregister gpio chip: %d\n", error
);
504 static int htcpld_setup_chips(struct platform_device
*pdev
)
506 struct htcpld_data
*htcpld
;
507 struct device
*dev
= &pdev
->dev
;
508 struct htcpld_core_platform_data
*pdata
;
511 /* Get the platform and driver data */
512 pdata
= dev
->platform_data
;
513 htcpld
= platform_get_drvdata(pdev
);
515 /* Setup each chip's output GPIOs */
516 htcpld
->nchips
= pdata
->num_chip
;
517 htcpld
->chip
= devm_kzalloc(dev
, sizeof(struct htcpld_chip
) * htcpld
->nchips
,
520 dev_warn(dev
, "Unable to allocate memory for chips\n");
524 /* Add the chips as best we can */
525 for (i
= 0; i
< htcpld
->nchips
; i
++) {
528 /* Setup the HTCPLD chips */
529 htcpld
->chip
[i
].reset
= pdata
->chip
[i
].reset
;
530 htcpld
->chip
[i
].cache_out
= pdata
->chip
[i
].reset
;
531 htcpld
->chip
[i
].cache_in
= 0;
532 htcpld
->chip
[i
].dev
= dev
;
533 htcpld
->chip
[i
].irq_start
= pdata
->chip
[i
].irq_base
;
534 htcpld
->chip
[i
].nirqs
= pdata
->chip
[i
].num_irqs
;
536 INIT_WORK(&(htcpld
->chip
[i
].set_val_work
), &htcpld_chip_set_ni
);
537 spin_lock_init(&(htcpld
->chip
[i
].lock
));
539 /* Setup the interrupts for the chip */
540 if (htcpld
->chained_irq
) {
541 ret
= htcpld_setup_chip_irq(pdev
, i
);
546 /* Register the chip with I2C */
547 ret
= htcpld_register_chip_i2c(pdev
, i
);
552 /* Register the chips with the GPIO subsystem */
553 ret
= htcpld_register_chip_gpio(pdev
, i
);
555 /* Unregister the chip from i2c and continue */
556 htcpld_unregister_chip_i2c(pdev
, i
);
560 dev_info(dev
, "Registered chip at 0x%x\n", pdata
->chip
[i
].addr
);
566 static int htcpld_core_probe(struct platform_device
*pdev
)
568 struct htcpld_data
*htcpld
;
569 struct device
*dev
= &pdev
->dev
;
570 struct htcpld_core_platform_data
*pdata
;
571 struct resource
*res
;
577 pdata
= dev
->platform_data
;
579 dev_warn(dev
, "Platform data not found for htcpld core!\n");
583 htcpld
= devm_kzalloc(dev
, sizeof(struct htcpld_data
), GFP_KERNEL
);
587 /* Find chained irq */
588 res
= platform_get_resource(pdev
, IORESOURCE_IRQ
, 0);
591 htcpld
->chained_irq
= res
->start
;
593 /* Setup the chained interrupt handler */
594 flags
= IRQF_TRIGGER_FALLING
| IRQF_TRIGGER_RISING
;
595 ret
= request_threaded_irq(htcpld
->chained_irq
,
596 NULL
, htcpld_handler
,
597 flags
, pdev
->name
, htcpld
);
599 dev_warn(dev
, "Unable to setup chained irq handler: %d\n", ret
);
602 device_init_wakeup(dev
, 0);
605 /* Set the driver data */
606 platform_set_drvdata(pdev
, htcpld
);
608 /* Setup the htcpld chips */
609 ret
= htcpld_setup_chips(pdev
);
613 /* Request the GPIO(s) for the int reset and set them up */
614 if (pdata
->int_reset_gpio_hi
) {
615 ret
= gpio_request(pdata
->int_reset_gpio_hi
, "htcpld-core");
618 * If it failed, that sucks, but we can probably
619 * continue on without it.
621 dev_warn(dev
, "Unable to request int_reset_gpio_hi -- interrupts may not work\n");
622 htcpld
->int_reset_gpio_hi
= 0;
624 htcpld
->int_reset_gpio_hi
= pdata
->int_reset_gpio_hi
;
625 gpio_set_value(htcpld
->int_reset_gpio_hi
, 1);
629 if (pdata
->int_reset_gpio_lo
) {
630 ret
= gpio_request(pdata
->int_reset_gpio_lo
, "htcpld-core");
633 * If it failed, that sucks, but we can probably
634 * continue on without it.
636 dev_warn(dev
, "Unable to request int_reset_gpio_lo -- interrupts may not work\n");
637 htcpld
->int_reset_gpio_lo
= 0;
639 htcpld
->int_reset_gpio_lo
= pdata
->int_reset_gpio_lo
;
640 gpio_set_value(htcpld
->int_reset_gpio_lo
, 0);
644 dev_info(dev
, "Initialized successfully\n");
648 /* The I2C Driver -- used internally */
649 static const struct i2c_device_id htcpld_chip_id
[] = {
650 { "htcpld-chip", 0 },
653 MODULE_DEVICE_TABLE(i2c
, htcpld_chip_id
);
656 static struct i2c_driver htcpld_chip_driver
= {
658 .name
= "htcpld-chip",
660 .id_table
= htcpld_chip_id
,
663 /* The Core Driver */
664 static struct platform_driver htcpld_core_driver
= {
666 .name
= "i2c-htcpld",
670 static int __init
htcpld_core_init(void)
674 /* Register the I2C Chip driver */
675 ret
= i2c_add_driver(&htcpld_chip_driver
);
679 /* Probe for our chips */
680 return platform_driver_probe(&htcpld_core_driver
, htcpld_core_probe
);
683 static void __exit
htcpld_core_exit(void)
685 i2c_del_driver(&htcpld_chip_driver
);
686 platform_driver_unregister(&htcpld_core_driver
);
689 module_init(htcpld_core_init
);
690 module_exit(htcpld_core_exit
);
692 MODULE_AUTHOR("Cory Maccarrone <darkstar6262@gmail.com>");
693 MODULE_DESCRIPTION("I2C HTC PLD Driver");
694 MODULE_LICENSE("GPL");