29 Kernel Input subsystem multi-point reporting mechanism implementation

The capacitive screen is widely used, and the multi-touch mechanism also develops. Unfortunately, the 29 kernel does not support multi-point reporting, which will be supported by the kernel after 30.

We hereby record the porting process.

 

1. Modify include/Linux/input. h.

 Index: Include/Linux/input. h <br/> ============================================ =====================================< br/> --- include/Linux /input. H (Revision 1550) <br/> ++ include/Linux/input. H (working copy) <br/>-106,6 + 106,7 </P> <p> # define syn_report 0 <br/> # define syn_config 1 <br/> + # define syn_mt_report 2 </P> <p>/* <br/> * keys and buttons <br/>-644,6 + 645,18 <br/> # define abs_tool_width 0x1c <br/> # define abs_volume 0x20 <br/> # define abs_misc 0x28 <br/> + # define abs_mt_touch_major 0x30/* major axis of touching Ellipse */<br/> + # define abs_mt_touch_minor 0x31/* minor axis (omit if circular) */<br/> + # define abs_mt_width_major 0x32/* major axis of Approaching Ellipse */<br/> + # define abs_mt_width_minor 0x33/* minor axis (omit if circular) */<br/> + # define abs_mt_orientation 0x34/* ellipse orientation */<br/> + # define abs_mt_position_x 0x35/* center x ellipse position */<br /> + # define abs_mt_position_y 0x36/* center y ellipse position */<br/> + # define abs_mt_tool_type 0x37/* type of touching device */<br/> + # define abs_mt_blob_id 0x38/* group a set of packets as a blob */<br/> + # define abs_mt_tracking_id 0x39/* unique ID of initiated contact */< br/> + <br/> # define abs_max 0x3f <br/> # define abs_cnt (abs_max + 1) </P> <p >- 742,6 + 755,12 <br/> # define bus_atari 0x1b </P> <p>/* <br/> + * mt_tool types <br/> + */<br/> + # define mt_tool_finger 0 <br/> + # define mt_tool_pen 1 <br/> +/* <br/> * values describing the status of a force-feedback effect <br/> */<br/> # define ff_status_stopped 0x00 <br/> @-1310,6 + 1329,11 @@ <br/> input_event (Dev, ev_syn, syn_report, 0); <br/>}</P> <p> + static inline void input_mt_sync (struct input_dev * Dev) <br/> + {<br/> + input_event (Dev, ev_syn, syn_mt_report, 0 ); <br/>+}< br/> + <br/> void input_set_capability (struct input_dev * Dev, unsigned int type, unsigned int Code );

 

2. Modify Drivers/input. C.

Index: Drivers/input. c <br/> ======================================== ===================================< br/> --- Drivers/Input /input. C (Revision 1550) <br/> ++ Drivers/input. C (working copy) <br/>-29,6 + 29,25 </P> <p> # define input_devices 256 </P> <p> +/* <br/> + * ev_abs events which shoshould not be cached are listed here. <br/> + */<br/> + static unsigned int input_abs_bypass_init_data [] _ initd ATA = {<br/> + abs_mt_touch_major, <br/> + abs_mt_touch_minor, <br/> + region, <br/> + abs_mt_width_minor, <br/> + abs_mt_orientation, <br/> + abs_mt_position_x, <br/> + abs_mt_position_y, <br/> + abs_mt_tool_type, <br/> + abs_mt_blob_id, <br/> + abs_mt_tracking_id, <br/> + 0 <br/> + }; <br/> + static unsigned long input_abs_bypass [bits_to_longs (abs_cnt)]; <br/> + <br/> static list_head (input _ Dev_list); <br/> static list_head (input_handler_list); </P> <p >- 149,13 + 168,17 <br/> case syn_config: <br/> disposition = input_pass_to_all; <br/> break; <br/>-<br/> + <br/> case syn_report: <br/> If (! Dev-> sync) {<br/> Dev-> sync = 1; <br/> disposition = input_pass_to_handlers; <br/>}< br/> break; <br/> + case syn_mt_report: <br/> + Dev-> sync = 0; <br/> + disposition = input_pass_to_handlers; <br/> + break; <br/>}< br/> break; </P> <p>-185, 6 + 208,11 <br/> case ev_abs: <br/> If (is_event_supported (Code, Dev-> absbit, abs_max) {</P> <p> + If (test_bit (Code, input_abs_bypass )) {<br/> + disposition = input_pass_to_handlers; <br/> + break; <br/>+}< br/>+ <br/> value = input_defuzz_abs_event (value, <br/> Dev-> ABS [Code], Dev-> absfuzz [Code]); </P> <p >- 1630,10 + 1658,20 <br/>. open = input_open_file, <br/>}; </P> <p> + static void _ init input_init_abs_bypass (void) <br/> + {<br/> + const unsigned int * P; <br/> + for (P = input_abs_bypass_init_data; * P; P ++) <br/> + input_abs_bypass [bit_word (* P)] | = bit_mask (* P ); <br/>{}< br/> + <br/> static int _ init input_init (void) <br/>{< br/> int err; </P> <p> + input_init_abs_bypass (); <br/> + <br/> err = class_register (& input_class); <br/> If (ERR) {<br/> printk (kern_err "input: unable to register input_dev class/N ");

 

3. Input subsystem Initialization

Input_dev-> evbit [0] = bit (ev_syn) | bit (ev_key) | bit (ev_abs ); <br/> input_dev-> absbit [0] = <br/> bit_mask (abs_x) | <br/> bit_mask (abs_y) | <br/> bit_mask (abs_mt_touch_major) | <br/> bit_mask (latency) | <br/> bit_mask (abs_mt_position_x) | <br/> bit_mask (abs_mt_position_y) | <br/> bit_mask (abs_mt_tracking_id );

 

4. subsystem reporting

Input_report_key (ts-> input, abs_mt_tracking_id, touch_num); <br/> input_report_abs (ts-> input, abs_mt_position_x, mxt224_datablock.t_point [touch_num]. x); <br/> input_report_abs (ts-> input, abs_mt_position_y, mxt224_datablock.t_point [touch_num]. y); <br/> input_report_abs (ts-> input, abs_mt_touch_major, mxt224_datablock.t_point [touch_num]. amplnum); <br/> input_report_abs (ts-> input, abs_mt_width_major, mxt224_datablock.t_point [touch_num]. area); <br/> input_report_abs (ts-> input, abs_pressure, mxt224_datablock.t_gesture [touch_num]. value); <br/>/* input_report_key (ts-> input, btn_touch, 1); */</P> <p> input_mt_sync (ts-> input );

 

Note: Please indicate the source for reprinting.