1 files changed, 441 insertions, 0 deletions

diff --git a/drivers/input/misc/gpio_matrix.c b/drivers/input/misc/gpio_matrix.c
new file mode 100644
index 000000000000..eaa9e89d473a
--- /dev/null
+++ b/drivers/input/misc/gpio_matrix.c
@@ -0,0 +1,441 @@
+/* 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/slab.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 int disabled_irq:1;
+	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);
+			input_report_key(kp->input_devs->dev[dev], keycode, pressed);
+		}
+	}
+}
+
+static void report_sync(struct gpio_kp *kp)
+{
+	int i;
+
+	for (i = 0; i < kp->input_devs->count; i++)
+		input_sync(kp->input_devs->dev[i]);
+}
+
+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);
+		report_sync(kp);
+	}
+	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 */
+		kp->disabled_irq = 1;
+		disable_irq_nosync(irq_in);
+		return IRQ_HANDLED;
+	}
+
+	for (i = 0; i < mi->ninputs; i++)
+		disable_irq_nosync(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 = enable_irq_wake(irq);
+		if (err) {
+			pr_err("gpiomatrix: set_irq_wake failed for input %d, "
+				"irq %d\n", mi->input_gpios[i], irq);
+		}
+		disable_irq(irq);
+		if (kp->disabled_irq) {
+			kp->disabled_irq = 0;
+			enable_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 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++) {
+			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 (gpio_cansleep(mi->output_gpios[i])) {
+				pr_err("gpiomatrix: unsupported output gpio %d,"
+					" can sleep\n", mi->output_gpios[i]);
+				err = -EINVAL;
+				goto err_output_gpio_configure_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%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, 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:
+		;
+	}
+err_bad_keymap:
+	kfree(kp);
+err_kp_alloc_failed:
+err_invalid_platform_data:
+	return err;
+}