446 lines
12 KiB
C
446 lines
12 KiB
C
/* drivers/input/misc/gpio_matrix.c
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*
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* Copyright (C) 2007 Google, Inc.
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/gpio.h>
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#include <linux/gpio_event.h>
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#include <linux/hrtimer.h>
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#include <linux/interrupt.h>
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#include <linux/slab.h>
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struct gpio_kp {
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struct gpio_event_input_devs *input_devs;
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struct gpio_event_matrix_info *keypad_info;
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struct hrtimer timer;
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struct wakeup_source wake_src;
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int current_output;
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unsigned int use_irq:1;
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unsigned int key_state_changed:1;
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unsigned int last_key_state_changed:1;
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unsigned int some_keys_pressed:2;
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unsigned int disabled_irq:1;
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unsigned long keys_pressed[0];
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};
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static void clear_phantom_key(struct gpio_kp *kp, int out, int in)
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{
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struct gpio_event_matrix_info *mi = kp->keypad_info;
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int key_index = out * mi->ninputs + in;
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unsigned short keyentry = mi->keymap[key_index];
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unsigned short keycode = keyentry & MATRIX_KEY_MASK;
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unsigned short dev = keyentry >> MATRIX_CODE_BITS;
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if (!test_bit(keycode, kp->input_devs->dev[dev]->key)) {
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if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS)
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pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) "
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"cleared\n", keycode, out, in,
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mi->output_gpios[out], mi->input_gpios[in]);
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__clear_bit(key_index, kp->keys_pressed);
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} else {
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if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS)
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pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) "
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"not cleared\n", keycode, out, in,
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mi->output_gpios[out], mi->input_gpios[in]);
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}
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}
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static int restore_keys_for_input(struct gpio_kp *kp, int out, int in)
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{
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int rv = 0;
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int key_index;
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key_index = out * kp->keypad_info->ninputs + in;
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while (out < kp->keypad_info->noutputs) {
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if (test_bit(key_index, kp->keys_pressed)) {
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rv = 1;
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clear_phantom_key(kp, out, in);
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}
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key_index += kp->keypad_info->ninputs;
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out++;
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}
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return rv;
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}
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static void remove_phantom_keys(struct gpio_kp *kp)
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{
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int out, in, inp;
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int key_index;
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if (kp->some_keys_pressed < 3)
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return;
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for (out = 0; out < kp->keypad_info->noutputs; out++) {
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inp = -1;
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key_index = out * kp->keypad_info->ninputs;
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for (in = 0; in < kp->keypad_info->ninputs; in++, key_index++) {
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if (test_bit(key_index, kp->keys_pressed)) {
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if (inp == -1) {
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inp = in;
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continue;
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}
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if (inp >= 0) {
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if (!restore_keys_for_input(kp, out + 1,
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inp))
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break;
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clear_phantom_key(kp, out, inp);
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inp = -2;
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}
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restore_keys_for_input(kp, out, in);
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}
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}
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}
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}
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static void report_key(struct gpio_kp *kp, int key_index, int out, int in)
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{
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struct gpio_event_matrix_info *mi = kp->keypad_info;
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int pressed = test_bit(key_index, kp->keys_pressed);
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unsigned short keyentry = mi->keymap[key_index];
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unsigned short keycode = keyentry & MATRIX_KEY_MASK;
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unsigned short dev = keyentry >> MATRIX_CODE_BITS;
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if (pressed != test_bit(keycode, kp->input_devs->dev[dev]->key)) {
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if (keycode == KEY_RESERVED) {
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if (mi->flags & GPIOKPF_PRINT_UNMAPPED_KEYS)
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pr_info("gpiomatrix: unmapped key, %d-%d "
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"(%d-%d) changed to %d\n",
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out, in, mi->output_gpios[out],
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mi->input_gpios[in], pressed);
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} else {
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if (mi->flags & GPIOKPF_PRINT_MAPPED_KEYS)
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pr_info("gpiomatrix: key %x, %d-%d (%d-%d) "
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"changed to %d\n", keycode,
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out, in, mi->output_gpios[out],
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mi->input_gpios[in], pressed);
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input_report_key(kp->input_devs->dev[dev], keycode, pressed);
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}
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}
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}
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static void report_sync(struct gpio_kp *kp)
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{
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int i;
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for (i = 0; i < kp->input_devs->count; i++)
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input_sync(kp->input_devs->dev[i]);
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}
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static enum hrtimer_restart gpio_keypad_timer_func(struct hrtimer *timer)
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{
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int out, in;
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int key_index;
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int gpio;
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struct gpio_kp *kp = container_of(timer, struct gpio_kp, timer);
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struct gpio_event_matrix_info *mi = kp->keypad_info;
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unsigned gpio_keypad_flags = mi->flags;
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unsigned polarity = !!(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH);
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out = kp->current_output;
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if (out == mi->noutputs) {
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out = 0;
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kp->last_key_state_changed = kp->key_state_changed;
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kp->key_state_changed = 0;
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kp->some_keys_pressed = 0;
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} else {
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key_index = out * mi->ninputs;
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for (in = 0; in < mi->ninputs; in++, key_index++) {
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gpio = mi->input_gpios[in];
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if (gpio_get_value(gpio) ^ !polarity) {
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if (kp->some_keys_pressed < 3)
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kp->some_keys_pressed++;
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kp->key_state_changed |= !__test_and_set_bit(
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key_index, kp->keys_pressed);
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} else
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kp->key_state_changed |= __test_and_clear_bit(
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key_index, kp->keys_pressed);
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}
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gpio = mi->output_gpios[out];
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if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
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gpio_set_value(gpio, !polarity);
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else
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gpio_direction_input(gpio);
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out++;
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}
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kp->current_output = out;
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if (out < mi->noutputs) {
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gpio = mi->output_gpios[out];
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if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
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gpio_set_value(gpio, polarity);
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else
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gpio_direction_output(gpio, polarity);
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hrtimer_start(timer, mi->settle_time, HRTIMER_MODE_REL);
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return HRTIMER_NORESTART;
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}
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if (gpio_keypad_flags & GPIOKPF_DEBOUNCE) {
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if (kp->key_state_changed) {
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hrtimer_start(&kp->timer, mi->debounce_delay,
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HRTIMER_MODE_REL);
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return HRTIMER_NORESTART;
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}
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kp->key_state_changed = kp->last_key_state_changed;
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}
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if (kp->key_state_changed) {
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if (gpio_keypad_flags & GPIOKPF_REMOVE_SOME_PHANTOM_KEYS)
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remove_phantom_keys(kp);
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key_index = 0;
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for (out = 0; out < mi->noutputs; out++)
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for (in = 0; in < mi->ninputs; in++, key_index++)
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report_key(kp, key_index, out, in);
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report_sync(kp);
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}
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if (!kp->use_irq || kp->some_keys_pressed) {
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hrtimer_start(timer, mi->poll_time, HRTIMER_MODE_REL);
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return HRTIMER_NORESTART;
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}
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/* No keys are pressed, reenable interrupt */
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for (out = 0; out < mi->noutputs; out++) {
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if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
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gpio_set_value(mi->output_gpios[out], polarity);
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else
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gpio_direction_output(mi->output_gpios[out], polarity);
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}
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for (in = 0; in < mi->ninputs; in++)
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enable_irq(gpio_to_irq(mi->input_gpios[in]));
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__pm_relax(&kp->wake_src);
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return HRTIMER_NORESTART;
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}
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static irqreturn_t gpio_keypad_irq_handler(int irq_in, void *dev_id)
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{
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int i;
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struct gpio_kp *kp = dev_id;
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struct gpio_event_matrix_info *mi = kp->keypad_info;
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unsigned gpio_keypad_flags = mi->flags;
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if (!kp->use_irq) {
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/* ignore interrupt while registering the handler */
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kp->disabled_irq = 1;
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disable_irq_nosync(irq_in);
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return IRQ_HANDLED;
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}
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for (i = 0; i < mi->ninputs; i++)
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disable_irq_nosync(gpio_to_irq(mi->input_gpios[i]));
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for (i = 0; i < mi->noutputs; i++) {
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if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
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gpio_set_value(mi->output_gpios[i],
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!(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH));
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else
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gpio_direction_input(mi->output_gpios[i]);
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}
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__pm_stay_awake(&kp->wake_src);
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hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
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return IRQ_HANDLED;
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}
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static int gpio_keypad_request_irqs(struct gpio_kp *kp)
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{
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int i;
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int err;
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unsigned int irq;
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unsigned long request_flags;
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struct gpio_event_matrix_info *mi = kp->keypad_info;
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switch (mi->flags & (GPIOKPF_ACTIVE_HIGH|GPIOKPF_LEVEL_TRIGGERED_IRQ)) {
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default:
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request_flags = IRQF_TRIGGER_FALLING;
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break;
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case GPIOKPF_ACTIVE_HIGH:
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request_flags = IRQF_TRIGGER_RISING;
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break;
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case GPIOKPF_LEVEL_TRIGGERED_IRQ:
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request_flags = IRQF_TRIGGER_LOW;
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break;
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case GPIOKPF_LEVEL_TRIGGERED_IRQ | GPIOKPF_ACTIVE_HIGH:
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request_flags = IRQF_TRIGGER_HIGH;
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break;
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}
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for (i = 0; i < mi->ninputs; i++) {
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err = irq = gpio_to_irq(mi->input_gpios[i]);
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if (err < 0)
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goto err_gpio_get_irq_num_failed;
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err = request_irq(irq, gpio_keypad_irq_handler, request_flags,
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"gpio_kp", kp);
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if (err) {
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pr_err("gpiomatrix: request_irq failed for input %d, "
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"irq %d\n", mi->input_gpios[i], irq);
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goto err_request_irq_failed;
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}
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err = enable_irq_wake(irq);
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if (err) {
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pr_err("gpiomatrix: set_irq_wake failed for input %d, "
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"irq %d\n", mi->input_gpios[i], irq);
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}
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disable_irq(irq);
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if (kp->disabled_irq) {
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kp->disabled_irq = 0;
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enable_irq(irq);
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}
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}
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return 0;
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for (i = mi->noutputs - 1; i >= 0; i--) {
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free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
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err_request_irq_failed:
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err_gpio_get_irq_num_failed:
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;
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}
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return err;
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}
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int gpio_event_matrix_func(struct gpio_event_input_devs *input_devs,
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struct gpio_event_info *info, void **data, int func)
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{
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int i;
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int err;
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int key_count;
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struct gpio_kp *kp;
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struct gpio_event_matrix_info *mi;
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mi = container_of(info, struct gpio_event_matrix_info, info);
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if (func == GPIO_EVENT_FUNC_SUSPEND || func == GPIO_EVENT_FUNC_RESUME) {
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/* TODO: disable scanning */
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return 0;
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}
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if (func == GPIO_EVENT_FUNC_INIT) {
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if (mi->keymap == NULL ||
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mi->input_gpios == NULL ||
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mi->output_gpios == NULL) {
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err = -ENODEV;
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pr_err("gpiomatrix: Incomplete pdata\n");
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goto err_invalid_platform_data;
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}
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key_count = mi->ninputs * mi->noutputs;
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*data = kp = kzalloc(sizeof(*kp) + sizeof(kp->keys_pressed[0]) *
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BITS_TO_LONGS(key_count), GFP_KERNEL);
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if (kp == NULL) {
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err = -ENOMEM;
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pr_err("gpiomatrix: Failed to allocate private data\n");
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goto err_kp_alloc_failed;
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}
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kp->input_devs = input_devs;
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kp->keypad_info = mi;
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for (i = 0; i < key_count; i++) {
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unsigned short keyentry = mi->keymap[i];
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unsigned short keycode = keyentry & MATRIX_KEY_MASK;
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unsigned short dev = keyentry >> MATRIX_CODE_BITS;
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if (dev >= input_devs->count) {
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pr_err("gpiomatrix: bad device index %d >= "
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"%d for key code %d\n",
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dev, input_devs->count, keycode);
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err = -EINVAL;
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goto err_bad_keymap;
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}
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if (keycode && keycode <= KEY_MAX)
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input_set_capability(input_devs->dev[dev],
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EV_KEY, keycode);
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}
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for (i = 0; i < mi->noutputs; i++) {
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err = gpio_request(mi->output_gpios[i], "gpio_kp_out");
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if (err) {
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pr_err("gpiomatrix: gpio_request failed for "
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"output %d\n", mi->output_gpios[i]);
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goto err_request_output_gpio_failed;
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}
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if (gpio_cansleep(mi->output_gpios[i])) {
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pr_err("gpiomatrix: unsupported output gpio %d,"
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" can sleep\n", mi->output_gpios[i]);
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err = -EINVAL;
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goto err_output_gpio_configure_failed;
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}
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if (mi->flags & GPIOKPF_DRIVE_INACTIVE)
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err = gpio_direction_output(mi->output_gpios[i],
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!(mi->flags & GPIOKPF_ACTIVE_HIGH));
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else
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err = gpio_direction_input(mi->output_gpios[i]);
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if (err) {
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pr_err("gpiomatrix: gpio_configure failed for "
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"output %d\n", mi->output_gpios[i]);
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goto err_output_gpio_configure_failed;
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}
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}
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for (i = 0; i < mi->ninputs; i++) {
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err = gpio_request(mi->input_gpios[i], "gpio_kp_in");
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if (err) {
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pr_err("gpiomatrix: gpio_request failed for "
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"input %d\n", mi->input_gpios[i]);
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goto err_request_input_gpio_failed;
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}
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err = gpio_direction_input(mi->input_gpios[i]);
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if (err) {
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pr_err("gpiomatrix: gpio_direction_input failed"
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" for input %d\n", mi->input_gpios[i]);
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goto err_gpio_direction_input_failed;
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}
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}
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kp->current_output = mi->noutputs;
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kp->key_state_changed = 1;
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hrtimer_init(&kp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
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kp->timer.function = gpio_keypad_timer_func;
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wakeup_source_init(&kp->wake_src, "gpio_kp");
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err = gpio_keypad_request_irqs(kp);
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kp->use_irq = err == 0;
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pr_info("GPIO Matrix Keypad Driver: Start keypad matrix for "
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"%s%s in %s mode\n", input_devs->dev[0]->name,
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(input_devs->count > 1) ? "..." : "",
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kp->use_irq ? "interrupt" : "polling");
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if (kp->use_irq)
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__pm_stay_awake(&kp->wake_src);
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hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
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return 0;
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}
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err = 0;
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kp = *data;
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if (kp->use_irq)
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for (i = mi->noutputs - 1; i >= 0; i--)
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free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
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hrtimer_cancel(&kp->timer);
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wakeup_source_trash(&kp->wake_src);
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for (i = mi->noutputs - 1; i >= 0; i--) {
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err_gpio_direction_input_failed:
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gpio_free(mi->input_gpios[i]);
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err_request_input_gpio_failed:
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;
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}
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for (i = mi->noutputs - 1; i >= 0; i--) {
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err_output_gpio_configure_failed:
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gpio_free(mi->output_gpios[i]);
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err_request_output_gpio_failed:
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;
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}
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err_bad_keymap:
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kfree(kp);
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err_kp_alloc_failed:
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err_invalid_platform_data:
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return err;
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}
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MODULE_DESCRIPTION("GPIO matrix driver");
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MODULE_AUTHOR("Google, Inc");
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MODULE_LICENSE("GPL v2");
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