blob: 6a0c31510968566d678a09a7cadb8bf18929940b [file] [log] [blame]
/* drivers/input/misc/gpio_input.c
*
* Copyright (C) 2007 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/kernel.h>
#include <linux/gpio.h>
#include <linux/gpio_event.h>
#include <linux/hrtimer.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/wakelock.h>
enum {
DEBOUNCE_UNSTABLE = BIT(0), /* Got irq, while debouncing */
DEBOUNCE_PRESSED = BIT(1),
DEBOUNCE_NOTPRESSED = BIT(2),
DEBOUNCE_WAIT_IRQ = BIT(3), /* Stable irq state */
DEBOUNCE_POLL = BIT(4), /* Stable polling state */
DEBOUNCE_UNKNOWN =
DEBOUNCE_PRESSED | DEBOUNCE_NOTPRESSED,
};
struct gpio_key_state {
struct gpio_input_state *ds;
uint8_t debounce;
};
struct gpio_input_state {
struct gpio_event_input_devs *input_devs;
const struct gpio_event_input_info *info;
struct hrtimer timer;
int use_irq;
int debounce_count;
spinlock_t irq_lock;
struct wake_lock wake_lock;
struct gpio_key_state key_state[0];
};
static enum hrtimer_restart gpio_event_input_timer_func(struct hrtimer *timer)
{
int i;
int pressed;
struct gpio_input_state *ds =
container_of(timer, struct gpio_input_state, timer);
unsigned gpio_flags = ds->info->flags;
unsigned npolarity;
int nkeys = ds->info->keymap_size;
const struct gpio_event_direct_entry *key_entry;
struct gpio_key_state *key_state;
unsigned long irqflags;
uint8_t debounce;
bool sync_needed;
#if 0
key_entry = kp->keys_info->keymap;
key_state = kp->key_state;
for (i = 0; i < nkeys; i++, key_entry++, key_state++)
pr_info("gpio_read_detect_status %d %d\n", key_entry->gpio,
gpio_read_detect_status(key_entry->gpio));
#endif
key_entry = ds->info->keymap;
key_state = ds->key_state;
sync_needed = false;
spin_lock_irqsave(&ds->irq_lock, irqflags);
for (i = 0; i < nkeys; i++, key_entry++, key_state++) {
debounce = key_state->debounce;
if (debounce & DEBOUNCE_WAIT_IRQ)
continue;
if (key_state->debounce & DEBOUNCE_UNSTABLE) {
debounce = key_state->debounce = DEBOUNCE_UNKNOWN;
enable_irq(gpio_to_irq(key_entry->gpio));
if (gpio_flags & GPIOEDF_PRINT_KEY_UNSTABLE)
pr_info("gpio_keys_scan_keys: key %x-%x, %d "
"(%d) continue debounce\n",
ds->info->type, key_entry->code,
i, key_entry->gpio);
}
npolarity = !(gpio_flags & GPIOEDF_ACTIVE_HIGH);
pressed = gpio_get_value(key_entry->gpio) ^ npolarity;
if (debounce & DEBOUNCE_POLL) {
if (pressed == !(debounce & DEBOUNCE_PRESSED)) {
ds->debounce_count++;
key_state->debounce = DEBOUNCE_UNKNOWN;
if (gpio_flags & GPIOEDF_PRINT_KEY_DEBOUNCE)
pr_info("gpio_keys_scan_keys: key %x-"
"%x, %d (%d) start debounce\n",
ds->info->type, key_entry->code,
i, key_entry->gpio);
}
continue;
}
if (pressed && (debounce & DEBOUNCE_NOTPRESSED)) {
if (gpio_flags & GPIOEDF_PRINT_KEY_DEBOUNCE)
pr_info("gpio_keys_scan_keys: key %x-%x, %d "
"(%d) debounce pressed 1\n",
ds->info->type, key_entry->code,
i, key_entry->gpio);
key_state->debounce = DEBOUNCE_PRESSED;
continue;
}
if (!pressed && (debounce & DEBOUNCE_PRESSED)) {
if (gpio_flags & GPIOEDF_PRINT_KEY_DEBOUNCE)
pr_info("gpio_keys_scan_keys: key %x-%x, %d "
"(%d) debounce pressed 0\n",
ds->info->type, key_entry->code,
i, key_entry->gpio);
key_state->debounce = DEBOUNCE_NOTPRESSED;
continue;
}
/* key is stable */
ds->debounce_count--;
if (ds->use_irq)
key_state->debounce |= DEBOUNCE_WAIT_IRQ;
else
key_state->debounce |= DEBOUNCE_POLL;
if (gpio_flags & GPIOEDF_PRINT_KEYS)
pr_info("gpio_keys_scan_keys: key %x-%x, %d (%d) "
"changed to %d\n", ds->info->type,
key_entry->code, i, key_entry->gpio, pressed);
input_event(ds->input_devs->dev[key_entry->dev], ds->info->type,
key_entry->code, pressed);
sync_needed = true;
}
if (sync_needed) {
for (i = 0; i < ds->input_devs->count; i++)
input_sync(ds->input_devs->dev[i]);
}
#if 0
key_entry = kp->keys_info->keymap;
key_state = kp->key_state;
for (i = 0; i < nkeys; i++, key_entry++, key_state++) {
pr_info("gpio_read_detect_status %d %d\n", key_entry->gpio,
gpio_read_detect_status(key_entry->gpio));
}
#endif
if (ds->debounce_count)
hrtimer_start(timer, ds->info->debounce_time, HRTIMER_MODE_REL);
else if (!ds->use_irq)
hrtimer_start(timer, ds->info->poll_time, HRTIMER_MODE_REL);
else
wake_unlock(&ds->wake_lock);
spin_unlock_irqrestore(&ds->irq_lock, irqflags);
return HRTIMER_NORESTART;
}
static irqreturn_t gpio_event_input_irq_handler(int irq, void *dev_id)
{
struct gpio_key_state *ks = dev_id;
struct gpio_input_state *ds = ks->ds;
int keymap_index = ks - ds->key_state;
const struct gpio_event_direct_entry *key_entry;
unsigned long irqflags;
int pressed;
if (!ds->use_irq)
return IRQ_HANDLED;
key_entry = &ds->info->keymap[keymap_index];
if (ds->info->debounce_time.tv64) {
spin_lock_irqsave(&ds->irq_lock, irqflags);
if (ks->debounce & DEBOUNCE_WAIT_IRQ) {
ks->debounce = DEBOUNCE_UNKNOWN;
if (ds->debounce_count++ == 0) {
wake_lock(&ds->wake_lock);
hrtimer_start(
&ds->timer, ds->info->debounce_time,
HRTIMER_MODE_REL);
}
if (ds->info->flags & GPIOEDF_PRINT_KEY_DEBOUNCE)
pr_info("gpio_event_input_irq_handler: "
"key %x-%x, %d (%d) start debounce\n",
ds->info->type, key_entry->code,
keymap_index, key_entry->gpio);
} else {
disable_irq_nosync(irq);
ks->debounce = DEBOUNCE_UNSTABLE;
}
spin_unlock_irqrestore(&ds->irq_lock, irqflags);
} else {
pressed = gpio_get_value(key_entry->gpio) ^
!(ds->info->flags & GPIOEDF_ACTIVE_HIGH);
if (ds->info->flags & GPIOEDF_PRINT_KEYS)
pr_info("gpio_event_input_irq_handler: key %x-%x, %d "
"(%d) changed to %d\n",
ds->info->type, key_entry->code, keymap_index,
key_entry->gpio, pressed);
input_event(ds->input_devs->dev[key_entry->dev], ds->info->type,
key_entry->code, pressed);
input_sync(ds->input_devs->dev[key_entry->dev]);
}
return IRQ_HANDLED;
}
static int gpio_event_input_request_irqs(struct gpio_input_state *ds)
{
int i;
int err;
unsigned int irq;
unsigned long req_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
for (i = 0; i < ds->info->keymap_size; i++) {
err = irq = gpio_to_irq(ds->info->keymap[i].gpio);
if (err < 0)
goto err_gpio_get_irq_num_failed;
err = request_irq(irq, gpio_event_input_irq_handler,
req_flags, "gpio_keys", &ds->key_state[i]);
if (err) {
pr_err("gpio_event_input_request_irqs: request_irq "
"failed for input %d, irq %d\n",
ds->info->keymap[i].gpio, irq);
goto err_request_irq_failed;
}
if (ds->info->info.no_suspend) {
err = enable_irq_wake(irq);
if (err) {
pr_err("gpio_event_input_request_irqs: "
"enable_irq_wake failed for input %d, "
"irq %d\n",
ds->info->keymap[i].gpio, irq);
goto err_enable_irq_wake_failed;
}
}
}
return 0;
for (i = ds->info->keymap_size - 1; i >= 0; i--) {
irq = gpio_to_irq(ds->info->keymap[i].gpio);
if (ds->info->info.no_suspend)
disable_irq_wake(irq);
err_enable_irq_wake_failed:
free_irq(irq, &ds->key_state[i]);
err_request_irq_failed:
err_gpio_get_irq_num_failed:
;
}
return err;
}
int gpio_event_input_func(struct gpio_event_input_devs *input_devs,
struct gpio_event_info *info, void **data, int func)
{
int ret;
int i;
unsigned long irqflags;
struct gpio_event_input_info *di;
struct gpio_input_state *ds = *data;
di = container_of(info, struct gpio_event_input_info, info);
if (func == GPIO_EVENT_FUNC_SUSPEND) {
if (ds->use_irq)
for (i = 0; i < di->keymap_size; i++)
disable_irq(gpio_to_irq(di->keymap[i].gpio));
hrtimer_cancel(&ds->timer);
return 0;
}
if (func == GPIO_EVENT_FUNC_RESUME) {
spin_lock_irqsave(&ds->irq_lock, irqflags);
if (ds->use_irq)
for (i = 0; i < di->keymap_size; i++)
enable_irq(gpio_to_irq(di->keymap[i].gpio));
hrtimer_start(&ds->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
spin_unlock_irqrestore(&ds->irq_lock, irqflags);
return 0;
}
if (func == GPIO_EVENT_FUNC_INIT) {
if (ktime_to_ns(di->poll_time) <= 0)
di->poll_time = ktime_set(0, 20 * NSEC_PER_MSEC);
*data = ds = kzalloc(sizeof(*ds) + sizeof(ds->key_state[0]) *
di->keymap_size, GFP_KERNEL);
if (ds == NULL) {
ret = -ENOMEM;
pr_err("gpio_event_input_func: "
"Failed to allocate private data\n");
goto err_ds_alloc_failed;
}
ds->debounce_count = di->keymap_size;
ds->input_devs = input_devs;
ds->info = di;
wake_lock_init(&ds->wake_lock, WAKE_LOCK_SUSPEND, "gpio_input");
spin_lock_init(&ds->irq_lock);
for (i = 0; i < di->keymap_size; i++) {
int dev = di->keymap[i].dev;
if (dev >= input_devs->count) {
pr_err("gpio_event_input_func: bad device "
"index %d >= %d for key code %d\n",
dev, input_devs->count,
di->keymap[i].code);
ret = -EINVAL;
goto err_bad_keymap;
}
input_set_capability(input_devs->dev[dev], di->type,
di->keymap[i].code);
ds->key_state[i].ds = ds;
ds->key_state[i].debounce = DEBOUNCE_UNKNOWN;
}
for (i = 0; i < di->keymap_size; i++) {
ret = gpio_request(di->keymap[i].gpio, "gpio_kp_in");
if (ret) {
pr_err("gpio_event_input_func: gpio_request "
"failed for %d\n", di->keymap[i].gpio);
goto err_gpio_request_failed;
}
ret = gpio_direction_input(di->keymap[i].gpio);
if (ret) {
pr_err("gpio_event_input_func: "
"gpio_direction_input failed for %d\n",
di->keymap[i].gpio);
goto err_gpio_configure_failed;
}
}
ret = gpio_event_input_request_irqs(ds);
spin_lock_irqsave(&ds->irq_lock, irqflags);
ds->use_irq = ret == 0;
pr_info("GPIO Input Driver: Start gpio inputs for %s%s in %s "
"mode\n", input_devs->dev[0]->name,
(input_devs->count > 1) ? "..." : "",
ret == 0 ? "interrupt" : "polling");
hrtimer_init(&ds->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
ds->timer.function = gpio_event_input_timer_func;
hrtimer_start(&ds->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
spin_unlock_irqrestore(&ds->irq_lock, irqflags);
return 0;
}
ret = 0;
spin_lock_irqsave(&ds->irq_lock, irqflags);
hrtimer_cancel(&ds->timer);
if (ds->use_irq) {
for (i = di->keymap_size - 1; i >= 0; i--) {
int irq = gpio_to_irq(di->keymap[i].gpio);
if (ds->info->info.no_suspend)
disable_irq_wake(irq);
free_irq(irq, &ds->key_state[i]);
}
}
spin_unlock_irqrestore(&ds->irq_lock, irqflags);
for (i = di->keymap_size - 1; i >= 0; i--) {
err_gpio_configure_failed:
gpio_free(di->keymap[i].gpio);
err_gpio_request_failed:
;
}
err_bad_keymap:
wake_lock_destroy(&ds->wake_lock);
kfree(ds);
err_ds_alloc_failed:
return ret;
}