Staging: dream: add support for input on GPIO pins
Support for input devices connected to GPIO pins. This adds support
for HTC Dream's keyboard and its trackball. Generic support already
exists for keyboard on GPIO, but this one is more advanced because it
can detect shadow key presses (and actually works with Dream :-).
(It also contains Kconfig/Makefile changes, including some that were
missing from previous commit. Sorry.)
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/dream/gpio_matrix.c b/drivers/staging/dream/gpio_matrix.c
new file mode 100644
index 0000000..c1f4765
--- /dev/null
+++ b/drivers/staging/dream/gpio_matrix.c
@@ -0,0 +1,406 @@
+/* drivers/input/misc/gpio_matrix.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/interrupt.h>
+#include <linux/wakelock.h>
+
+struct gpio_kp {
+ struct input_dev *input_dev;
+ 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 keycode = mi->keymap[key_index];;
+
+ if (!test_bit(keycode, kp->input_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 keycode = mi->keymap[key_index];
+ if (pressed != test_bit(keycode, kp->input_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);
+ input_report_key(kp->input_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, 0), 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;
+ }
+ err = set_irq_wake(irq, 1);
+ if (err) {
+ pr_err("gpiomatrix: set_irq_wake failed for input %d, "
+ "irq %d\n", mi->input_gpios[i], irq);
+ }
+ 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 gpio_event_matrix_func(struct input_dev *input_dev,
+ 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_dev = input_dev;
+ kp->keypad_info = mi;
+ set_bit(EV_KEY, input_dev->evbit);
+ for (i = 0; i < key_count; i++) {
+ if (mi->keymap[i])
+ set_bit(mi->keymap[i] & KEY_MAX,
+ input_dev->keybit);
+ }
+
+ 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("GPIO Matrix Keypad Driver: Start keypad matrix for %s "
+ "in %s mode\n", input_dev->name,
+ kp->use_irq ? "interrupt" : "polling");
+
+ if (kp->use_irq)
+ wake_lock(&kp->wake_lock);
+ hrtimer_start(&kp->timer, ktime_set(0, 0), 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:
+ ;
+ }
+ kfree(kp);
+err_kp_alloc_failed:
+err_invalid_platform_data:
+ return err;
+}