6c2c3c13e9
* tmk_core/common: Fixing TIMER_DIFF macro to calculate difference correctly after the timer wraps.
Let's go through an example, using the following macro:
If the first timer read is 0xe4 and the second one is 0x32, the timer wrapped.
If the timer would have had more bits, it's new value would have been 0x132,
and the correct difference in time is 0x132 - 0xe4 = 0x4e
old code TIMER_DIFF_8(0x32, 0xe4) = 0xff - 0xe4 + 0x32 = 0x4d, which is wrong.
new code TIMER_DIFF_8(0x32, 0xe4) = 0xff + 1 - 0xe4 + 0x32 = 0x4e, which is correct.
This also gives a chance for a smart compiler to optimize the code using normal
integer overflow.
For example on AVR, the following C code:
uint8_t __attribute__ ((noinline)) test(uint8_t current_timer, uint8_t start_timer)
{
return TIMER_DIFF_8(current_timer, start_timer);
}
With the original code, it gets translated to the following list of instructions:
00004c6e <test>:
4c6e: 98 2f mov r25, r24
4c70: 86 1b sub r24, r22
4c72: 96 17 cp r25, r22
4c74: 08 f4 brcc .+2 ; 0x4c78 <test+0xa>
4c76: 81 50 subi r24, 0x01 ; 1
4c78: 08 95 ret
But with this commit, it gets translated to a single instruction:
00004c40 <test>:
4c40: 86 1b sub r24, r22
4c42: 08 95 ret
This unfortunately doesn't always work so nicely, for example the following C code:
int __attribute__ ((noinline)) test(uint8_t current_timer, uint8_t start_timer)
{
return TIMER_DIFF_8(current_timer, start_timer);
}
(Note: return type changed to int)
With the original code it gets translated to:
00004c6e <test>:
4c6e: 28 2f mov r18, r24
4c70: 30 e0 ldi r19, 0x00 ; 0
4c72: 46 2f mov r20, r22
4c74: 50 e0 ldi r21, 0x00 ; 0
4c76: 86 17 cp r24, r22
4c78: 20 f0 brcs .+8 ; 0x4c82 <test+0x14>
4c7a: c9 01 movw r24, r18
4c7c: 84 1b sub r24, r20
4c7e: 95 0b sbc r25, r21
4c80: 08 95 ret
4c82: c9 01 movw r24, r18
4c84: 84 1b sub r24, r20
4c86: 95 0b sbc r25, r21
4c88: 81 50 subi r24, 0x01 ; 1
4c8a: 9f 4f sbci r25, 0xFF ; 255
4c8c: 08 95 ret
Wth this commit it gets translated to:
00004c40 <test>:
4c40: 28 2f mov r18, r24
4c42: 30 e0 ldi r19, 0x00 ; 0
4c44: 46 2f mov r20, r22
4c46: 50 e0 ldi r21, 0x00 ; 0
4c48: 86 17 cp r24, r22
4c4a: 20 f0 brcs .+8 ; 0x4c54 <test+0x14>
4c4c: c9 01 movw r24, r18
4c4e: 84 1b sub r24, r20
4c50: 95 0b sbc r25, r21
4c52: 08 95 ret
4c54: c9 01 movw r24, r18
4c56: 84 1b sub r24, r20
4c58: 95 0b sbc r25, r21
4c5a: 93 95 inc r25
4c5c: 08 95 ret
There is not much performance improvement in this case, however at least with this
commit it functions correctly.
Note: The following commit will improve compiler output for the latter example.
* tmk_core/common: Improve code generation for TIMER_DIFF* macros
Because of integer promotion the compiler is having a hard time generating
efficient code to calculate TIMER_DIFF* macros in some situations.
In the below example, the return value is "int", and this is causing the
trouble.
Example C code:
int __attribute__ ((noinline)) test(uint8_t current_timer, uint8_t start_timer)
{
return TIMER_DIFF_8(current_timer, start_timer);
}
BEFORE: (with -Os)
00004c40 <test>:
4c40: 28 2f mov r18, r24
4c42: 30 e0 ldi r19, 0x00 ; 0
4c44: 46 2f mov r20, r22
4c46: 50 e0 ldi r21, 0x00 ; 0
4c48: 86 17 cp r24, r22
4c4a: 20 f0 brcs .+8 ; 0x4c54 <test+0x14>
4c4c: c9 01 movw r24, r18
4c4e: 84 1b sub r24, r20
4c50: 95 0b sbc r25, r21
4c52: 08 95 ret
4c54: c9 01 movw r24, r18
4c56: 84 1b sub r24, r20
4c58: 95 0b sbc r25, r21
4c5a: 93 95 inc r25
4c5c: 08 95 ret
AFTER: (with -Os)
00004c40 <test>:
4c40: 86 1b sub r24, r22
4c42: 90 e0 ldi r25, 0x00 ; 0
4c44: 08 95 ret
Note: the example is showing -Os but improvements can be seen at all optimization levels,
including -O0. We never use -O0, but I tested it to make sure that no extra code is
generated in that case.OA
* quantum/debounce: Fix custom wrapping timers in eager_pr and eager_pk debounce algorithms
Please see the below simulated sequence of events:
Column A is the 16-bit value returned by read_timer();
Column B is the value returned by custom_wrap_timer_read();
Column C is the original code: (timer_read() % MAX_DEBOUNCE)
A, B, C
65530, 19, 30
65531, 20, 31
65532, 21, 32
65533, 22, 33
65534, 23, 34
65535, 24, 35
0 25, 0
1, 26, 1
2, 27, 2
3, 28, 3
4, 29, 4
5, 30, 5
read_timer() wraps about every 1.09 seconds, and so debouncing might
fail at these times without this commit.
* quantum/debounce/eager_pr and eager_pk: modifications for code readability according to code review.
* quantum/debounce/eager_pr and eager_pk: modifications for code readability according to code review. (2)
TMK Keyboard Firmware Core Library
This is a keyboard firmware library with some useful features for Atmel AVR and Cortex-M.
Source code is available here: https://github.com/tmk/tmk_keyboard/tree/master/tmk_core
Updates
2016/02/10
flabbergast's Chibios protocol was merged from https://github.com/flabbergast/tmk_keyboard/tree/chibios. See protocol/chibios/README.md. Chibios protocol supports Cortex-M such as STM32 and Kinetis.
2015/04/22
separated with TMK Keyboard Firmware Collection
Features
These features can be used in your keyboard.
- Multi-layer Keymap - Multiple keyboard layouts with layer switching
- Mouse key - Mouse control with keyboard
- System Control Key - Power Down, Sleep, Wake Up and USB Remote Wake up
- Media Control Key - Volume Down/Up, Mute, Next/Prev track, Play, Stop and etc
- USB NKRO - 248 keys(+ 8 modifiers) simultaneously
- PS/2 mouse support - PS/2 mouse(TrackPoint) as composite device
- Keyboard protocols - PS/2, ADB, M0110, Sun and other old keyboard protocols
- User Function - Customizable function of key with writing code
- Macro - Very primitive at this time
- Keyboard Tricks - Oneshot modifier and modifier with tapping feature
- Debug Console - Messages for debug and interaction with firmware
- Virtual DIP Switch - Configurations stored EEPROM(Boot Magic)
- Locking CapsLock - Mechanical switch support for CapsLock
- Breathing Sleep LED - Sleep indicator with charm during USB suspend
- Backlight - Control backlight levels
TMK Keyboard Firmware Collection
Complete firmwares for various keyboards and protocol converters.
https://github.com/tmk/tmk_keyboard
License
GPLv2 or later. Some protocol files are under Modified BSD License. ChibiOS, LUFA and V-USB stack have their own license respectively.
Build Firmware and Program Controller
See doc/build.md.
Start Your Own Project
TBD
Config.h Options
1. USB vendor/product ID and device description
#define VENDOR_ID 0xFEED
#define PRODUCT_ID 0xBEEF
#define MANUFACTURER t.m.k.
#define PRODUCT Macway mod
#define DESCRIPTION t.m.k. keyboard firmware for Macway mod
2. Keyboard matrix configuration
#define MATRIX_ROWS 8
#define MATRIX_COLS 8
#define MATRIX_HAS_GHOST
Architecture
Architecture Diagram
+---------------+---------------+-------------+
| Host | Keyboard | Matrix, LED |
___________ |-----------+-+ +-------------+ | +-----------|
/ /| Keys/Mouse | Protocol |d| | Action | | | Protocol |
/__________/ |<-----------| LUFA |r| | Layer, Tap | | | Matrix |
|.--------.| | LED | V-USB |i| |-------------| | | PS/2,IBM | __________________
|| || |----------->| iWRAP(BT)|v| | Keymap | | | ADB,M0110| Keys / /_/_/_/_/_/_/_/ /|
|| Host || | Console | UART |e| | Mousekey | | | SUN/NEWS |<----------/ /_/_/_/_/_/_/_/ / /
||________||/.<-----------| |r| | Report | | | X68K/PC98| Control / /_/_/_/_/_/_/_/ / /
`_========_'/| |---------------------------------------------|-------->/___ /_______/ ___/ /
|_o______o_|/ | Sendchar, Print, Debug, Command, ... | |_________________|/
+---------------------------------------------+ Keyboard
Debugging
Use PJRC's hid_listen to see debug messages. You can use the tool for debug even if firmware use LUFA stack.
You can use xprintf() to display debug info on hid_listen, see common/xprintf.h.
Files and Directories
Top
- common/ - common codes
- protocol/ - keyboard protocol support
- doc/ - documents
- common.mk - Makefile for common
- protocol.mk - Makefile for protocol
- rules.mk - Makefile for build rules
Common
- host.h
- host_driver.h
- keyboard.h
- command.h
- keymap.h
- action.h
- keycode.h
- matrix.h
- led.h
- mousekey.h
- report.h
- debug.h
- print.h
- bootloader.h
- sendchar.h
- timer.h
- util.h
Keyboard Protocols
- lufa/ - LUFA USB stack
- vusb/ - Objective Development V-USB
- iwrap/ - Bluetooth HID for Bluegiga iWRAP
- ps2.c - PS/2 protocol
- adb.c - Apple Desktop Bus protocol
- m0110.c - Macintosh 128K/512K/Plus keyboard protocol
- news.c - Sony NEWS keyboard protocol
- x68k.c - Sharp X68000 keyboard protocol
- serial_soft.c - Asynchronous Serial protocol implemented by software
Coding Style
- Doesn't use Tab to indent, use 4-spaces instead.