Input: Generic GPIO Input device.

Supports keyboard matrixces, direct inputs, direct outputs and axes connected to gpios.

Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Nick Pelly <npelly@google.com>

1 files changed, 154 insertions, 0 deletions

diff --git a/include/linux/gpio_event.h b/include/linux/gpio_event.h
new file mode 100644
index 000000000000..5ff828bcb6bc
--- /dev/null
+++ b/include/linux/gpio_event.h
@@ -0,0 +1,154 @@
+/* include/linux/gpio_event.h
+ *
+ * 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.
+ *
+ */
+
+#ifndef _LINUX_GPIO_EVENT_H
+#define _LINUX_GPIO_EVENT_H
+
+#include <linux/input.h>
+
+enum {
+	GPIO_EVENT_FUNC_UNINIT  = 0x0,
+	GPIO_EVENT_FUNC_INIT    = 0x1,
+	GPIO_EVENT_FUNC_SUSPEND = 0x2,
+	GPIO_EVENT_FUNC_RESUME  = 0x3,
+};
+struct gpio_event_info {
+	int (*func)(struct input_dev *input_dev,
+		    struct gpio_event_info *info,
+		    void **data, int func);
+	int (*event)(struct input_dev *input_dev,
+		     struct gpio_event_info *info,
+		     void **data, unsigned int type,
+		     unsigned int code, int value); /* out events */
+};
+
+struct gpio_event_platform_data {
+	const char *name;
+	struct gpio_event_info **info;
+	size_t info_count;
+	int (*power)(const struct gpio_event_platform_data *pdata, bool on);
+};
+
+#define GPIO_EVENT_DEV_NAME "gpio-event"
+
+/* Key matrix */
+
+enum gpio_event_matrix_flags {
+	/* unset: drive active output low, set: drive active output high */
+	GPIOKPF_ACTIVE_HIGH              = 1U << 0,
+	GPIOKPF_DEBOUNCE                 = 1U << 1,
+	GPIOKPF_REMOVE_SOME_PHANTOM_KEYS = 1U << 2,
+	GPIOKPF_REMOVE_PHANTOM_KEYS      = GPIOKPF_REMOVE_SOME_PHANTOM_KEYS |
+					   GPIOKPF_DEBOUNCE,
+	GPIOKPF_DRIVE_INACTIVE           = 1U << 3,
+	GPIOKPF_LEVEL_TRIGGERED_IRQ      = 1U << 4,
+	GPIOKPF_PRINT_UNMAPPED_KEYS      = 1U << 16,
+	GPIOKPF_PRINT_MAPPED_KEYS        = 1U << 17,
+	GPIOKPF_PRINT_PHANTOM_KEYS       = 1U << 18,
+};
+
+extern int gpio_event_matrix_func(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data, int func);
+struct gpio_event_matrix_info {
+	/* initialize to gpio_event_matrix_func */
+	struct gpio_event_info info;
+	/* size must be ninputs * noutputs */
+	const unsigned short *keymap;
+	unsigned int *input_gpios;
+	unsigned int *output_gpios;
+	unsigned int ninputs;
+	unsigned int noutputs;
+	/* time to wait before reading inputs after driving each output */
+	ktime_t settle_time;
+	/* time to wait before scanning the keypad a second time */
+	ktime_t debounce_delay;
+	ktime_t poll_time;
+	unsigned flags;
+};
+
+/* Directly connected inputs and outputs */
+
+enum gpio_event_direct_flags {
+	GPIOEDF_ACTIVE_HIGH         = 1U << 0,
+/*	GPIOEDF_USE_DOWN_IRQ        = 1U << 1, */
+/*	GPIOEDF_USE_IRQ             = (1U << 2) | GPIOIDF_USE_DOWN_IRQ, */
+	GPIOEDF_PRINT_KEYS          = 1U << 8,
+	GPIOEDF_PRINT_KEY_DEBOUNCE  = 1U << 9,
+};
+
+struct gpio_event_direct_entry {
+	uint32_t gpio:23;
+	uint32_t code:9;
+};
+
+/* inputs */
+extern int gpio_event_input_func(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data, int func);
+struct gpio_event_input_info {
+	/* initialize to gpio_event_input_func */
+	struct gpio_event_info info;
+	ktime_t debounce_time;
+	ktime_t poll_time;
+	uint16_t flags;
+	uint16_t type;
+	const struct gpio_event_direct_entry *keymap;
+	size_t keymap_size;
+};
+
+/* outputs */
+extern int gpio_event_output_func(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data, int func);
+extern int gpio_event_output_event(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data,
+			unsigned int type, unsigned int code, int value);
+struct gpio_event_output_info {
+	/* initialize to gpio_event_output_func and gpio_event_output_event */
+	struct gpio_event_info info;
+	uint16_t flags;
+	uint16_t type;
+	const struct gpio_event_direct_entry *keymap;
+	size_t keymap_size;
+};
+
+
+/* axes */
+
+enum gpio_event_axis_flags {
+	GPIOEAF_PRINT_UNKNOWN_DIRECTION  = 1U << 16,
+	GPIOEAF_PRINT_RAW                = 1U << 17,
+	GPIOEAF_PRINT_EVENT              = 1U << 18,
+};
+
+extern int gpio_event_axis_func(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data, int func);
+struct gpio_event_axis_info {
+	/* initialize to gpio_event_axis_func */
+	struct gpio_event_info info;
+	uint8_t  count;
+	uint8_t  type; /* EV_REL or EV_ABS */
+	uint16_t code;
+	uint16_t decoded_size;
+	uint16_t (*map)(struct gpio_event_axis_info *info, uint16_t in);
+	uint32_t *gpio;
+	uint32_t flags;
+};
+#define gpio_axis_2bit_gray_map gpio_axis_4bit_gray_map
+#define gpio_axis_3bit_gray_map gpio_axis_4bit_gray_map
+uint16_t gpio_axis_4bit_gray_map(
+			struct gpio_event_axis_info *info, uint16_t in);
+uint16_t gpio_axis_5bit_singletrack_map(
+			struct gpio_event_axis_info *info, uint16_t in);
+
+#endif