diff options
Diffstat (limited to 'drivers/input/input-mt.c')
| -rw-r--r-- | drivers/input/input-mt.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c new file mode 100644 index 000000000000..c48c81f0308d --- /dev/null +++ b/drivers/input/input-mt.c @@ -0,0 +1,170 @@ +/* + * Input Multitouch Library + * + * Copyright (c) 2008-2010 Henrik Rydberg + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/input/mt.h> +#include <linux/slab.h> + +#define TRKID_SGN ((TRKID_MAX + 1) >> 1) + +/** + * input_mt_init_slots() - initialize MT input slots + * @dev: input device supporting MT events and finger tracking + * @num_slots: number of slots used by the device + * + * This function allocates all necessary memory for MT slot handling + * in the input device, prepares the ABS_MT_SLOT and + * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers. + * May be called repeatedly. Returns -EINVAL if attempting to + * reinitialize with a different number of slots. + */ +int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots) +{ + int i; + + if (!num_slots) + return 0; + if (dev->mt) + return dev->mtsize != num_slots ? -EINVAL : 0; + + dev->mt = kcalloc(num_slots, sizeof(struct input_mt_slot), GFP_KERNEL); + if (!dev->mt) + return -ENOMEM; + + dev->mtsize = num_slots; + input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0); + input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0); + input_set_events_per_packet(dev, 6 * num_slots); + + /* Mark slots as 'unused' */ + for (i = 0; i < num_slots; i++) + input_mt_set_value(&dev->mt[i], ABS_MT_TRACKING_ID, -1); + + return 0; +} +EXPORT_SYMBOL(input_mt_init_slots); + +/** + * input_mt_destroy_slots() - frees the MT slots of the input device + * @dev: input device with allocated MT slots + * + * This function is only needed in error path as the input core will + * automatically free the MT slots when the device is destroyed. + */ +void input_mt_destroy_slots(struct input_dev *dev) +{ + kfree(dev->mt); + dev->mt = NULL; + dev->mtsize = 0; + dev->slot = 0; + dev->trkid = 0; +} +EXPORT_SYMBOL(input_mt_destroy_slots); + +/** + * input_mt_report_slot_state() - report contact state + * @dev: input device with allocated MT slots + * @tool_type: the tool type to use in this slot + * @active: true if contact is active, false otherwise + * + * Reports a contact via ABS_MT_TRACKING_ID, and optionally + * ABS_MT_TOOL_TYPE. If active is true and the slot is currently + * inactive, or if the tool type is changed, a new tracking id is + * assigned to the slot. The tool type is only reported if the + * corresponding absbit field is set. + */ +void input_mt_report_slot_state(struct input_dev *dev, + unsigned int tool_type, bool active) +{ + struct input_mt_slot *mt; + int id; + + if (!dev->mt || !active) { + input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); + return; + } + + mt = &dev->mt[dev->slot]; + id = input_mt_get_value(mt, ABS_MT_TRACKING_ID); + if (id < 0 || input_mt_get_value(mt, ABS_MT_TOOL_TYPE) != tool_type) + id = input_mt_new_trkid(dev); + + input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id); + input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type); +} +EXPORT_SYMBOL(input_mt_report_slot_state); + +/** + * input_mt_report_finger_count() - report contact count + * @dev: input device with allocated MT slots + * @count: the number of contacts + * + * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, + * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP. + * + * The input core ensures only the KEY events already setup for + * this device will produce output. + */ +void input_mt_report_finger_count(struct input_dev *dev, int count) +{ + input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1); + input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2); + input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3); + input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4); +} +EXPORT_SYMBOL(input_mt_report_finger_count); + +/** + * input_mt_report_pointer_emulation() - common pointer emulation + * @dev: input device with allocated MT slots + * @use_count: report number of active contacts as finger count + * + * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and + * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true. + * + * The input core ensures only the KEY and ABS axes already setup for + * this device will produce output. + */ +void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count) +{ + struct input_mt_slot *oldest = 0; + int oldid = dev->trkid; + int count = 0; + int i; + + for (i = 0; i < dev->mtsize; ++i) { + struct input_mt_slot *ps = &dev->mt[i]; + int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID); + + if (id < 0) + continue; + if ((id - oldid) & TRKID_SGN) { + oldest = ps; + oldid = id; + } + count++; + } + + input_event(dev, EV_KEY, BTN_TOUCH, count > 0); + if (use_count) + input_mt_report_finger_count(dev, count); + + if (oldest) { + int x = input_mt_get_value(oldest, ABS_MT_POSITION_X); + int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y); + int p = input_mt_get_value(oldest, ABS_MT_PRESSURE); + + input_event(dev, EV_ABS, ABS_X, x); + input_event(dev, EV_ABS, ABS_Y, y); + input_event(dev, EV_ABS, ABS_PRESSURE, p); + } else { + input_event(dev, EV_ABS, ABS_PRESSURE, 0); + } +} +EXPORT_SYMBOL(input_mt_report_pointer_emulation); |