[XPERIA X8 Android Development] i_hate_sonyericsson:
Source - semc_gpio_matrix.c

as said, the source files...

semc_gpio_matrix.c

/* drivers/misc/semc/gpio_matrix/gpio_matrix.c
*
* Copyright (C) 2010 Sony Ericsson Mobile Communications AB
*
* 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.
*
* Based upon kernel/drivers/input/misc/gpio_matrix.c
*/

#include <linux/kernel.h>
#include <linux/gpio.h>
#include <linux/gpio_event.h>
#include <linux/hrtimer.h>
#include <linux/interrupt.h>
#include <linux/wakelock.h>

struct gpio_kp {
struct gpio_event_input_devs *input_devs;
struct gpio_event_matrix_info *keypad_info;
struct hrtimer timer;
struct wake_lock wake_lock;
int current_output;
unsigned int use_irq:1;
unsigned int key_state_changed:1;
unsigned int last_key_state_changed:1;
unsigned int some_keys_pressed:2;
unsigned long keys_pressed[0];
};

static void clear_phantom_key(struct gpio_kp *kp, int out, int in)
{
struct gpio_event_matrix_info *mi = kp->keypad_info;
int key_index = out * mi->ninputs + in;
unsigned short keyentry = mi->keymap[key_index];
unsigned short keycode = keyentry & MATRIX_KEY_MASK;
unsigned short dev = keyentry >> MATRIX_CODE_BITS;

if (!test_bit(keycode, kp->input_devs->dev[dev]->key)) {
if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS)
pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) "
"cleared\n", keycode, out, in,
mi->output_gpios[out], mi->input_gpios[in]);
__clear_bit(key_index, kp->keys_pressed);
} else {
if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS)
pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) "
"not cleared\n", keycode, out, in,
mi->output_gpios[out], mi->input_gpios[in]);
}
}

static int restore_keys_for_input(struct gpio_kp *kp, int out, int in)
{
int rv = 0;
int key_index;

key_index = out * kp->keypad_info->ninputs + in;
while (out < kp->keypad_info->noutputs) {
if (test_bit(key_index, kp->keys_pressed)) {
rv = 1;
clear_phantom_key(kp, out, in);
}
key_index += kp->keypad_info->ninputs;
out++;
}
return rv;
}

static void remove_phantom_keys(struct gpio_kp *kp)
{
int out, in, inp;
int key_index;

if (kp->some_keys_pressed < 3)
return;

for (out = 0; out < kp->keypad_info->noutputs; out++) {
inp = -1;
key_index = out * kp->keypad_info->ninputs;
for (in = 0; in < kp->keypad_info->ninputs; in++, key_index++) {
if (test_bit(key_index, kp->keys_pressed)) {
if (inp == -1) {
inp = in;
continue;
}
if (inp >= 0) {
if (!restore_keys_for_input(kp, out + 1,
inp))
break;
clear_phantom_key(kp, out, inp);
inp = -2;
}
restore_keys_for_input(kp, out, in);
}
}
}
}

static void report_key(struct gpio_kp *kp, int key_index, int out, int in)
{
struct gpio_event_matrix_info *mi = kp->keypad_info;
int pressed = test_bit(key_index, kp->keys_pressed);
unsigned short keyentry = mi->keymap[key_index];
unsigned short keycode = keyentry & MATRIX_KEY_MASK;
unsigned short dev = keyentry >> MATRIX_CODE_BITS;

if (pressed != test_bit(keycode, kp->input_devs->dev[dev]->key)) {
if (keycode == KEY_RESERVED) {
if (mi->flags & GPIOKPF_PRINT_UNMAPPED_KEYS)
pr_info("gpiomatrix: unmapped key, %d-%d "
"(%d-%d) changed to %d\n",
out, in, mi->output_gpios[out],
mi->input_gpios[in], pressed);
} else {
if (mi->flags & GPIOKPF_PRINT_MAPPED_KEYS)
pr_info("gpiomatrix: key %x, %d-%d (%d-%d) "
"changed to %d\n", keycode,
out, in, mi->output_gpios[out],
mi->input_gpios[in], pressed);
if (mi->info.event)
mi->info.event(kp->input_devs, &mi->info, NULL, dev, 0,
keycode, pressed);
else
input_report_key(kp->input_devs->dev[dev], keycode, pressed);
}
}
}

static enum hrtimer_restart gpio_keypad_timer_func(struct hrtimer *timer)
{
int out, in;
int key_index;
int gpio;
struct gpio_kp *kp = container_of(timer, struct gpio_kp, timer);
struct gpio_event_matrix_info *mi = kp->keypad_info;
unsigned gpio_keypad_flags = mi->flags;
unsigned polarity = !!(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH);

out = kp->current_output;
if (out == mi->noutputs) {
out = 0;
kp->last_key_state_changed = kp->key_state_changed;
kp->key_state_changed = 0;
kp->some_keys_pressed = 0;
} else {
key_index = out * mi->ninputs;
for (in = 0; in < mi->ninputs; in++, key_index++) {
gpio = mi->input_gpios[in];
if (gpio_get_value(gpio) ^ !polarity) {
if (kp->some_keys_pressed < 3)
kp->some_keys_pressed++;
kp->key_state_changed |= !__test_and_set_bit(
key_index, kp->keys_pressed);
} else
kp->key_state_changed |= __test_and_clear_bit(
key_index, kp->keys_pressed);
}
gpio = mi->output_gpios[out];
if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
gpio_set_value(gpio, !polarity);
else
gpio_direction_input(gpio);
out++;
}
kp->current_output = out;
if (out < mi->noutputs) {
gpio = mi->output_gpios[out];
if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
gpio_set_value(gpio, polarity);
else
gpio_direction_output(gpio, polarity);
hrtimer_start(timer, mi->settle_time, HRTIMER_MODE_REL);
return HRTIMER_NORESTART;
}
if (gpio_keypad_flags & GPIOKPF_DEBOUNCE) {
if (kp->key_state_changed) {
hrtimer_start(&kp->timer, mi->debounce_delay,
HRTIMER_MODE_REL);
return HRTIMER_NORESTART;
}
kp->key_state_changed = kp->last_key_state_changed;
}
if (kp->key_state_changed) {
if (gpio_keypad_flags & GPIOKPF_REMOVE_SOME_PHANTOM_KEYS)
remove_phantom_keys(kp);
key_index = 0;
for (out = 0; out < mi->noutputs; out++)
for (in = 0; in < mi->ninputs; in++, key_index++)
report_key(kp, key_index, out, in);
}
if (!kp->use_irq || kp->some_keys_pressed) {
hrtimer_start(timer, mi->poll_time, HRTIMER_MODE_REL);
return HRTIMER_NORESTART;
}

/* No keys are pressed, reenable interrupt */
for (out = 0; out < mi->noutputs; out++) {
if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
gpio_set_value(mi->output_gpios[out], polarity);
else
gpio_direction_output(mi->output_gpios[out], polarity);
}
for (in = 0; in < mi->ninputs; in++)
enable_irq(gpio_to_irq(mi->input_gpios[in]));
wake_unlock(&kp->wake_lock);
return HRTIMER_NORESTART;
}

static irqreturn_t gpio_keypad_irq_handler(int irq_in, void *dev_id)
{
int i;
struct gpio_kp *kp = dev_id;
struct gpio_event_matrix_info *mi = kp->keypad_info;
unsigned gpio_keypad_flags = mi->flags;

if (!kp->use_irq) /* ignore interrupt while registering the handler */
return IRQ_HANDLED;

for (i = 0; i < mi->ninputs; i++)
disable_irq(gpio_to_irq(mi->input_gpios[i]));
for (i = 0; i < mi->noutputs; i++) {
if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
gpio_set_value(mi->output_gpios[i],
!(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH));
else
gpio_direction_input(mi->output_gpios[i]);
}
wake_lock(&kp->wake_lock);
hrtimer_start(&kp->timer, ktime_set(0, 10000), HRTIMER_MODE_REL);
return IRQ_HANDLED;
}

static int gpio_keypad_request_irqs(struct gpio_kp *kp)
{
int i;
int err;
unsigned int irq;
unsigned long request_flags;
struct gpio_event_matrix_info *mi = kp->keypad_info;

switch (mi->flags & (GPIOKPF_ACTIVE_HIGH|GPIOKPF_LEVEL_TRIGGERED_IRQ)) {
default:
request_flags = IRQF_TRIGGER_FALLING;
break;
case GPIOKPF_ACTIVE_HIGH:
request_flags = IRQF_TRIGGER_RISING;
break;
case GPIOKPF_LEVEL_TRIGGERED_IRQ:
request_flags = IRQF_TRIGGER_LOW;
break;
case GPIOKPF_LEVEL_TRIGGERED_IRQ | GPIOKPF_ACTIVE_HIGH:
request_flags = IRQF_TRIGGER_HIGH;
break;
}

for (i = 0; i < mi->ninputs; i++) {
err = irq = gpio_to_irq(mi->input_gpios[i]);
if (err < 0)
goto err_gpio_get_irq_num_failed;
err = request_irq(irq, gpio_keypad_irq_handler, request_flags,
"gpio_kp", kp);
if (err) {
pr_err("gpiomatrix: request_irq failed for input %d, "
"irq %d\n", mi->input_gpios[i], irq);
goto err_request_irq_failed;
}
disable_irq(irq);
}
return 0;

for (i = mi->noutputs - 1; i >= 0; i--) {
free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
err_request_irq_failed:
err_gpio_get_irq_num_failed:
;
}
return err;
}

int semc_gpio_event_matrix_func(struct gpio_event_input_devs *input_devs,
struct gpio_event_info *info, void **data, int func)
{
int i;
int err;
int key_count;
struct gpio_kp *kp;
struct gpio_event_matrix_info *mi;

mi = container_of(info, struct gpio_event_matrix_info, info);
if (func == GPIO_EVENT_FUNC_SUSPEND || func == GPIO_EVENT_FUNC_RESUME) {
/* TODO: disable scanning */
return 0;
}

if (func == GPIO_EVENT_FUNC_INIT) {
if (mi->keymap == NULL ||
mi->input_gpios == NULL ||
mi->output_gpios == NULL) {
err = -ENODEV;
pr_err("gpiomatrix: Incomplete pdata\n");
goto err_invalid_platform_data;
}
key_count = mi->ninputs * mi->noutputs;

*data = kp = kzalloc(sizeof(*kp) + sizeof(kp->keys_pressed[0]) *
BITS_TO_LONGS(key_count), GFP_KERNEL);
if (kp == NULL) {
err = -ENOMEM;
pr_err("gpiomatrix: Failed to allocate private data\n");
goto err_kp_alloc_failed;
}
kp->input_devs = input_devs;
kp->keypad_info = mi;
for (i = 0; i < key_count; i++) {
unsigned short keyentry = mi->keymap[i];
unsigned short keycode = keyentry & MATRIX_KEY_MASK;
unsigned short dev = keyentry >> MATRIX_CODE_BITS;
if (dev >= input_devs->count) {
pr_err("gpiomatrix: bad device index %d >= "
"%d for key code %d\n",
dev, input_devs->count, keycode);
err = -EINVAL;
goto err_bad_keymap;
}
if (keycode && keycode <= KEY_MAX)
input_set_capability(input_devs->dev[dev],
EV_KEY, keycode);
}

for (i = 0; i < mi->noutputs; i++) {
if (gpio_cansleep(mi->output_gpios[i])) {
pr_err("gpiomatrix: unsupported output gpio %d,"
" can sleep\n", mi->output_gpios[i]);
err = -EINVAL;
goto err_request_output_gpio_failed;
}
err = gpio_request(mi->output_gpios[i], "gpio_kp_out");
if (err) {
pr_err("gpiomatrix: gpio_request failed for "
"output %d\n", mi->output_gpios[i]);
goto err_request_output_gpio_failed;
}
if (mi->flags & GPIOKPF_DRIVE_INACTIVE)
err = gpio_direction_output(mi->output_gpios[i],
!(mi->flags & GPIOKPF_ACTIVE_HIGH));
else
err = gpio_direction_input(mi->output_gpios[i]);
if (err) {
pr_err("gpiomatrix: gpio_configure failed for "
"output %d\n", mi->output_gpios[i]);
goto err_output_gpio_configure_failed;
}
}
for (i = 0; i < mi->ninputs; i++) {
err = gpio_request(mi->input_gpios[i], "gpio_kp_in");
if (err) {
pr_err("gpiomatrix: gpio_request failed for "
"input %d\n", mi->input_gpios[i]);
goto err_request_input_gpio_failed;
}
err = gpio_direction_input(mi->input_gpios[i]);
if (err) {
pr_err("gpiomatrix: gpio_direction_input failed"
" for input %d\n", mi->input_gpios[i]);
goto err_gpio_direction_input_failed;
}
}
kp->current_output = mi->noutputs;
kp->key_state_changed = 1;

hrtimer_init(&kp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
kp->timer.function = gpio_keypad_timer_func;
wake_lock_init(&kp->wake_lock, WAKE_LOCK_SUSPEND, "gpio_kp");
err = gpio_keypad_request_irqs(kp);
kp->use_irq = err == 0;

pr_info("SEMC GPIO Matrix Keypad Driver: Start keypad matrix for "
"%s%s in %s mode\n", input_devs->dev[0]->name,
(input_devs->count > 1) ? "..." : "",
kp->use_irq ? "interrupt" : "polling");

if (kp->use_irq)
wake_lock(&kp->wake_lock);
hrtimer_start(&kp->timer, ktime_set(0, 10000),
HRTIMER_MODE_REL);

return 0;
}

err = 0;
kp = *data;

if (kp->use_irq)
for (i = mi->noutputs - 1; i >= 0; i--)
free_irq(gpio_to_irq(mi->input_gpios[i]), kp);

hrtimer_cancel(&kp->timer);
wake_lock_destroy(&kp->wake_lock);
for (i = mi->noutputs - 1; i >= 0; i--) {
err_gpio_direction_input_failed:
gpio_free(mi->input_gpios[i]);
err_request_input_gpio_failed:
;
}
for (i = mi->noutputs - 1; i >= 0; i--) {
err_output_gpio_configure_failed:
gpio_free(mi->output_gpios[i]);
err_request_output_gpio_failed:
;
}
err_bad_keymap:
kfree(kp);
err_kp_alloc_failed:
err_invalid_platform_data:
return err;
}