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Diffstat (limited to 'quantum/backlight/backlight_avr.c')
-rw-r--r-- | quantum/backlight/backlight_avr.c | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/quantum/backlight/backlight_avr.c b/quantum/backlight/backlight_avr.c new file mode 100644 index 000000000..445698f47 --- /dev/null +++ b/quantum/backlight/backlight_avr.c | |||
@@ -0,0 +1,509 @@ | |||
1 | #include "quantum.h" | ||
2 | #include "backlight.h" | ||
3 | #include "debug.h" | ||
4 | |||
5 | #if defined(BACKLIGHT_ENABLE) && (defined(BACKLIGHT_PIN) || defined(BACKLIGHT_PINS)) | ||
6 | |||
7 | // This logic is a bit complex, we support 3 setups: | ||
8 | // | ||
9 | // 1. Hardware PWM when backlight is wired to a PWM pin. | ||
10 | // Depending on this pin, we use a different output compare unit. | ||
11 | // 2. Software PWM with hardware timers, but the used timer | ||
12 | // depends on the Audio setup (Audio wins over Backlight). | ||
13 | // 3. Full software PWM, driven by the matrix scan, if both timers are used by Audio. | ||
14 | |||
15 | # if (defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__) || defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)) && (BACKLIGHT_PIN == B5 || BACKLIGHT_PIN == B6 || BACKLIGHT_PIN == B7) | ||
16 | # define HARDWARE_PWM | ||
17 | # define ICRx ICR1 | ||
18 | # define TCCRxA TCCR1A | ||
19 | # define TCCRxB TCCR1B | ||
20 | # define TIMERx_OVF_vect TIMER1_OVF_vect | ||
21 | # define TIMSKx TIMSK1 | ||
22 | # define TOIEx TOIE1 | ||
23 | |||
24 | # if BACKLIGHT_PIN == B5 | ||
25 | # define COMxx1 COM1A1 | ||
26 | # define OCRxx OCR1A | ||
27 | # elif BACKLIGHT_PIN == B6 | ||
28 | # define COMxx1 COM1B1 | ||
29 | # define OCRxx OCR1B | ||
30 | # elif BACKLIGHT_PIN == B7 | ||
31 | # define COMxx1 COM1C1 | ||
32 | # define OCRxx OCR1C | ||
33 | # endif | ||
34 | # elif (defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__) || defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)) && (BACKLIGHT_PIN == C4 || BACKLIGHT_PIN == C5 || BACKLIGHT_PIN == C6) | ||
35 | # define HARDWARE_PWM | ||
36 | # define ICRx ICR3 | ||
37 | # define TCCRxA TCCR3A | ||
38 | # define TCCRxB TCCR3B | ||
39 | # define TIMERx_OVF_vect TIMER3_OVF_vect | ||
40 | # define TIMSKx TIMSK3 | ||
41 | # define TOIEx TOIE3 | ||
42 | |||
43 | # if BACKLIGHT_PIN == C4 | ||
44 | # if (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)) | ||
45 | # error This MCU has no C4 pin! | ||
46 | # else | ||
47 | # define COMxx1 COM3C1 | ||
48 | # define OCRxx OCR3C | ||
49 | # endif | ||
50 | # elif BACKLIGHT_PIN == C5 | ||
51 | # if (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)) | ||
52 | # error This MCU has no C5 pin! | ||
53 | # else | ||
54 | # define COMxx1 COM3B1 | ||
55 | # define OCRxx OCR3B | ||
56 | # endif | ||
57 | # elif BACKLIGHT_PIN == C6 | ||
58 | # define COMxx1 COM3A1 | ||
59 | # define OCRxx OCR3A | ||
60 | # endif | ||
61 | # elif (defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega32U2__)) && (BACKLIGHT_PIN == B7 || BACKLIGHT_PIN == C5 || BACKLIGHT_PIN == C6) | ||
62 | # define HARDWARE_PWM | ||
63 | # define ICRx ICR1 | ||
64 | # define TCCRxA TCCR1A | ||
65 | # define TCCRxB TCCR1B | ||
66 | # define TIMERx_OVF_vect TIMER1_OVF_vect | ||
67 | # define TIMSKx TIMSK1 | ||
68 | # define TOIEx TOIE1 | ||
69 | |||
70 | # if BACKLIGHT_PIN == B7 | ||
71 | # define COMxx1 COM1C1 | ||
72 | # define OCRxx OCR1C | ||
73 | # elif BACKLIGHT_PIN == C5 | ||
74 | # define COMxx1 COM1B1 | ||
75 | # define OCRxx OCR1B | ||
76 | # elif BACKLIGHT_PIN == C6 | ||
77 | # define COMxx1 COM1A1 | ||
78 | # define OCRxx OCR1A | ||
79 | # endif | ||
80 | # elif defined(__AVR_ATmega32A__) && (BACKLIGHT_PIN == D4 || BACKLIGHT_PIN == D5) | ||
81 | # define HARDWARE_PWM | ||
82 | # define ICRx ICR1 | ||
83 | # define TCCRxA TCCR1A | ||
84 | # define TCCRxB TCCR1B | ||
85 | # define TIMERx_OVF_vect TIMER1_OVF_vect | ||
86 | # define TIMSKx TIMSK | ||
87 | # define TOIEx TOIE1 | ||
88 | |||
89 | # if BACKLIGHT_PIN == D4 | ||
90 | # define COMxx1 COM1B1 | ||
91 | # define OCRxx OCR1B | ||
92 | # elif BACKLIGHT_PIN == D5 | ||
93 | # define COMxx1 COM1A1 | ||
94 | # define OCRxx OCR1A | ||
95 | # endif | ||
96 | # elif defined(__AVR_ATmega328P__) && (BACKLIGHT_PIN == B1 || BACKLIGHT_PIN == B2) | ||
97 | # define HARDWARE_PWM | ||
98 | # define ICRx ICR1 | ||
99 | # define TCCRxA TCCR1A | ||
100 | # define TCCRxB TCCR1B | ||
101 | # define TIMERx_OVF_vect TIMER1_OVF_vect | ||
102 | # define TIMSKx TIMSK1 | ||
103 | # define TOIEx TOIE1 | ||
104 | |||
105 | # if BACKLIGHT_PIN == B1 | ||
106 | # define COMxx1 COM1A1 | ||
107 | # define OCRxx OCR1A | ||
108 | # elif BACKLIGHT_PIN == B2 | ||
109 | # define COMxx1 COM1B1 | ||
110 | # define OCRxx OCR1B | ||
111 | # endif | ||
112 | # else | ||
113 | # if !defined(BACKLIGHT_CUSTOM_DRIVER) | ||
114 | # if !defined(B5_AUDIO) && !defined(B6_AUDIO) && !defined(B7_AUDIO) | ||
115 | // Timer 1 is not in use by Audio feature, Backlight can use it | ||
116 | # pragma message "Using hardware timer 1 with software PWM" | ||
117 | # define HARDWARE_PWM | ||
118 | # define BACKLIGHT_PWM_TIMER | ||
119 | # define ICRx ICR1 | ||
120 | # define TCCRxA TCCR1A | ||
121 | # define TCCRxB TCCR1B | ||
122 | # define TIMERx_COMPA_vect TIMER1_COMPA_vect | ||
123 | # define TIMERx_OVF_vect TIMER1_OVF_vect | ||
124 | # if defined(__AVR_ATmega32A__) // This MCU has only one TIMSK register | ||
125 | # define TIMSKx TIMSK | ||
126 | # else | ||
127 | # define TIMSKx TIMSK1 | ||
128 | # endif | ||
129 | # define TOIEx TOIE1 | ||
130 | |||
131 | # define OCIExA OCIE1A | ||
132 | # define OCRxx OCR1A | ||
133 | # elif !defined(C6_AUDIO) && !defined(C5_AUDIO) && !defined(C4_AUDIO) | ||
134 | # pragma message "Using hardware timer 3 with software PWM" | ||
135 | // Timer 3 is not in use by Audio feature, Backlight can use it | ||
136 | # define HARDWARE_PWM | ||
137 | # define BACKLIGHT_PWM_TIMER | ||
138 | # define ICRx ICR1 | ||
139 | # define TCCRxA TCCR3A | ||
140 | # define TCCRxB TCCR3B | ||
141 | # define TIMERx_COMPA_vect TIMER3_COMPA_vect | ||
142 | # define TIMERx_OVF_vect TIMER3_OVF_vect | ||
143 | # define TIMSKx TIMSK3 | ||
144 | # define TOIEx TOIE3 | ||
145 | |||
146 | # define OCIExA OCIE3A | ||
147 | # define OCRxx OCR3A | ||
148 | # else | ||
149 | # pragma message "Audio in use - using pure software PWM" | ||
150 | # define NO_HARDWARE_PWM | ||
151 | # endif | ||
152 | # else | ||
153 | # pragma message "Custom driver defined - using pure software PWM" | ||
154 | # define NO_HARDWARE_PWM | ||
155 | # endif | ||
156 | # endif | ||
157 | |||
158 | # ifndef BACKLIGHT_ON_STATE | ||
159 | # define BACKLIGHT_ON_STATE 0 | ||
160 | # endif | ||
161 | |||
162 | void backlight_on(uint8_t backlight_pin) { | ||
163 | # if BACKLIGHT_ON_STATE == 0 | ||
164 | writePinLow(backlight_pin); | ||
165 | # else | ||
166 | writePinHigh(backlight_pin); | ||
167 | # endif | ||
168 | } | ||
169 | |||
170 | void backlight_off(uint8_t backlight_pin) { | ||
171 | # if BACKLIGHT_ON_STATE == 0 | ||
172 | writePinHigh(backlight_pin); | ||
173 | # else | ||
174 | writePinLow(backlight_pin); | ||
175 | # endif | ||
176 | } | ||
177 | |||
178 | # if defined(NO_HARDWARE_PWM) || defined(BACKLIGHT_PWM_TIMER) // pwm through software | ||
179 | |||
180 | // we support multiple backlight pins | ||
181 | # ifndef BACKLIGHT_LED_COUNT | ||
182 | # define BACKLIGHT_LED_COUNT 1 | ||
183 | # endif | ||
184 | |||
185 | # if BACKLIGHT_LED_COUNT == 1 | ||
186 | # define BACKLIGHT_PIN_INIT \ | ||
187 | { BACKLIGHT_PIN } | ||
188 | # else | ||
189 | # define BACKLIGHT_PIN_INIT BACKLIGHT_PINS | ||
190 | # endif | ||
191 | |||
192 | # define FOR_EACH_LED(x) \ | ||
193 | for (uint8_t i = 0; i < BACKLIGHT_LED_COUNT; i++) { \ | ||
194 | uint8_t backlight_pin = backlight_pins[i]; \ | ||
195 | { x } \ | ||
196 | } | ||
197 | |||
198 | static const uint8_t backlight_pins[BACKLIGHT_LED_COUNT] = BACKLIGHT_PIN_INIT; | ||
199 | |||
200 | # else // full hardware PWM | ||
201 | |||
202 | // we support only one backlight pin | ||
203 | static const uint8_t backlight_pin = BACKLIGHT_PIN; | ||
204 | # define FOR_EACH_LED(x) x | ||
205 | |||
206 | # endif | ||
207 | |||
208 | # ifdef NO_HARDWARE_PWM | ||
209 | __attribute__((weak)) void backlight_init_ports(void) { | ||
210 | // Setup backlight pin as output and output to on state. | ||
211 | FOR_EACH_LED(setPinOutput(backlight_pin); backlight_on(backlight_pin);) | ||
212 | |||
213 | # ifdef BACKLIGHT_BREATHING | ||
214 | if (is_backlight_breathing()) { | ||
215 | breathing_enable(); | ||
216 | } | ||
217 | # endif | ||
218 | } | ||
219 | |||
220 | __attribute__((weak)) void backlight_set(uint8_t level) {} | ||
221 | |||
222 | uint8_t backlight_tick = 0; | ||
223 | |||
224 | # ifndef BACKLIGHT_CUSTOM_DRIVER | ||
225 | void backlight_task(void) { | ||
226 | if ((0xFFFF >> ((BACKLIGHT_LEVELS - get_backlight_level()) * ((BACKLIGHT_LEVELS + 1) / 2))) & (1 << backlight_tick)) { | ||
227 | FOR_EACH_LED(backlight_on(backlight_pin);) | ||
228 | } else { | ||
229 | FOR_EACH_LED(backlight_off(backlight_pin);) | ||
230 | } | ||
231 | backlight_tick = (backlight_tick + 1) % 16; | ||
232 | } | ||
233 | # endif | ||
234 | |||
235 | # ifdef BACKLIGHT_BREATHING | ||
236 | # ifndef BACKLIGHT_CUSTOM_DRIVER | ||
237 | # error "Backlight breathing only available with hardware PWM. Please disable." | ||
238 | # endif | ||
239 | # endif | ||
240 | |||
241 | # else // hardware pwm through timer | ||
242 | |||
243 | # ifdef BACKLIGHT_PWM_TIMER | ||
244 | |||
245 | // The idea of software PWM assisted by hardware timers is the following | ||
246 | // we use the hardware timer in fast PWM mode like for hardware PWM, but | ||
247 | // instead of letting the Output Match Comparator control the led pin | ||
248 | // (which is not possible since the backlight is not wired to PWM pins on the | ||
249 | // CPU), we do the LED on/off by oursleves. | ||
250 | // The timer is setup to count up to 0xFFFF, and we set the Output Compare | ||
251 | // register to the current 16bits backlight level (after CIE correction). | ||
252 | // This means the CPU will trigger a compare match interrupt when the counter | ||
253 | // reaches the backlight level, where we turn off the LEDs, | ||
254 | // but also an overflow interrupt when the counter rolls back to 0, | ||
255 | // in which we're going to turn on the LEDs. | ||
256 | // The LED will then be on for OCRxx/0xFFFF time, adjusted every 244Hz. | ||
257 | |||
258 | // Triggered when the counter reaches the OCRx value | ||
259 | ISR(TIMERx_COMPA_vect) { FOR_EACH_LED(backlight_off(backlight_pin);) } | ||
260 | |||
261 | // Triggered when the counter reaches the TOP value | ||
262 | // this one triggers at F_CPU/65536 =~ 244 Hz | ||
263 | ISR(TIMERx_OVF_vect) { | ||
264 | # ifdef BACKLIGHT_BREATHING | ||
265 | if (is_breathing()) { | ||
266 | breathing_task(); | ||
267 | } | ||
268 | # endif | ||
269 | // for very small values of OCRxx (or backlight level) | ||
270 | // we can't guarantee this whole code won't execute | ||
271 | // at the same time as the compare match interrupt | ||
272 | // which means that we might turn on the leds while | ||
273 | // trying to turn them off, leading to flickering | ||
274 | // artifacts (especially while breathing, because breathing_task | ||
275 | // takes many computation cycles). | ||
276 | // so better not turn them on while the counter TOP is very low. | ||
277 | if (OCRxx > 256) { | ||
278 | FOR_EACH_LED(backlight_on(backlight_pin);) | ||
279 | } | ||
280 | } | ||
281 | |||
282 | # endif | ||
283 | |||
284 | # define TIMER_TOP 0xFFFFU | ||
285 | |||
286 | // See http://jared.geek.nz/2013/feb/linear-led-pwm | ||
287 | static uint16_t cie_lightness(uint16_t v) { | ||
288 | if (v <= 5243) // if below 8% of max | ||
289 | return v / 9; // same as dividing by 900% | ||
290 | else { | ||
291 | uint32_t y = (((uint32_t)v + 10486) << 8) / (10486 + 0xFFFFUL); // add 16% of max and compare | ||
292 | // to get a useful result with integer division, we shift left in the expression above | ||
293 | // and revert what we've done again after squaring. | ||
294 | y = y * y * y >> 8; | ||
295 | if (y > 0xFFFFUL) // prevent overflow | ||
296 | return 0xFFFFU; | ||
297 | else | ||
298 | return (uint16_t)y; | ||
299 | } | ||
300 | } | ||
301 | |||
302 | // range for val is [0..TIMER_TOP]. PWM pin is high while the timer count is below val. | ||
303 | static inline void set_pwm(uint16_t val) { OCRxx = val; } | ||
304 | |||
305 | # ifndef BACKLIGHT_CUSTOM_DRIVER | ||
306 | __attribute__((weak)) void backlight_set(uint8_t level) { | ||
307 | if (level > BACKLIGHT_LEVELS) level = BACKLIGHT_LEVELS; | ||
308 | |||
309 | if (level == 0) { | ||
310 | # ifdef BACKLIGHT_PWM_TIMER | ||
311 | if (OCRxx) { | ||
312 | TIMSKx &= ~(_BV(OCIExA)); | ||
313 | TIMSKx &= ~(_BV(TOIEx)); | ||
314 | FOR_EACH_LED(backlight_off(backlight_pin);) | ||
315 | } | ||
316 | # else | ||
317 | // Turn off PWM control on backlight pin | ||
318 | TCCRxA &= ~(_BV(COMxx1)); | ||
319 | # endif | ||
320 | } else { | ||
321 | # ifdef BACKLIGHT_PWM_TIMER | ||
322 | if (!OCRxx) { | ||
323 | TIMSKx |= _BV(OCIExA); | ||
324 | TIMSKx |= _BV(TOIEx); | ||
325 | } | ||
326 | # else | ||
327 | // Turn on PWM control of backlight pin | ||
328 | TCCRxA |= _BV(COMxx1); | ||
329 | # endif | ||
330 | } | ||
331 | // Set the brightness | ||
332 | set_pwm(cie_lightness(TIMER_TOP * (uint32_t)level / BACKLIGHT_LEVELS)); | ||
333 | } | ||
334 | |||
335 | void backlight_task(void) {} | ||
336 | # endif // BACKLIGHT_CUSTOM_DRIVER | ||
337 | |||
338 | # ifdef BACKLIGHT_BREATHING | ||
339 | |||
340 | # define BREATHING_NO_HALT 0 | ||
341 | # define BREATHING_HALT_OFF 1 | ||
342 | # define BREATHING_HALT_ON 2 | ||
343 | # define BREATHING_STEPS 128 | ||
344 | |||
345 | static uint8_t breathing_period = BREATHING_PERIOD; | ||
346 | static uint8_t breathing_halt = BREATHING_NO_HALT; | ||
347 | static uint16_t breathing_counter = 0; | ||
348 | |||
349 | # ifdef BACKLIGHT_PWM_TIMER | ||
350 | static bool breathing = false; | ||
351 | |||
352 | bool is_breathing(void) { return breathing; } | ||
353 | |||
354 | # define breathing_interrupt_enable() \ | ||
355 | do { \ | ||
356 | breathing = true; \ | ||
357 | } while (0) | ||
358 | # define breathing_interrupt_disable() \ | ||
359 | do { \ | ||
360 | breathing = false; \ | ||
361 | } while (0) | ||
362 | # else | ||
363 | |||
364 | bool is_breathing(void) { return !!(TIMSKx & _BV(TOIEx)); } | ||
365 | |||
366 | # define breathing_interrupt_enable() \ | ||
367 | do { \ | ||
368 | TIMSKx |= _BV(TOIEx); \ | ||
369 | } while (0) | ||
370 | # define breathing_interrupt_disable() \ | ||
371 | do { \ | ||
372 | TIMSKx &= ~_BV(TOIEx); \ | ||
373 | } while (0) | ||
374 | # endif | ||
375 | |||
376 | # define breathing_min() \ | ||
377 | do { \ | ||
378 | breathing_counter = 0; \ | ||
379 | } while (0) | ||
380 | # define breathing_max() \ | ||
381 | do { \ | ||
382 | breathing_counter = breathing_period * 244 / 2; \ | ||
383 | } while (0) | ||
384 | |||
385 | void breathing_enable(void) { | ||
386 | breathing_counter = 0; | ||
387 | breathing_halt = BREATHING_NO_HALT; | ||
388 | breathing_interrupt_enable(); | ||
389 | } | ||
390 | |||
391 | void breathing_pulse(void) { | ||
392 | if (get_backlight_level() == 0) | ||
393 | breathing_min(); | ||
394 | else | ||
395 | breathing_max(); | ||
396 | breathing_halt = BREATHING_HALT_ON; | ||
397 | breathing_interrupt_enable(); | ||
398 | } | ||
399 | |||
400 | void breathing_disable(void) { | ||
401 | breathing_interrupt_disable(); | ||
402 | // Restore backlight level | ||
403 | backlight_set(get_backlight_level()); | ||
404 | } | ||
405 | |||
406 | void breathing_self_disable(void) { | ||
407 | if (get_backlight_level() == 0) | ||
408 | breathing_halt = BREATHING_HALT_OFF; | ||
409 | else | ||
410 | breathing_halt = BREATHING_HALT_ON; | ||
411 | } | ||
412 | |||
413 | void breathing_toggle(void) { | ||
414 | if (is_breathing()) | ||
415 | breathing_disable(); | ||
416 | else | ||
417 | breathing_enable(); | ||
418 | } | ||
419 | |||
420 | void breathing_period_set(uint8_t value) { | ||
421 | if (!value) value = 1; | ||
422 | breathing_period = value; | ||
423 | } | ||
424 | |||
425 | void breathing_period_default(void) { breathing_period_set(BREATHING_PERIOD); } | ||
426 | |||
427 | void breathing_period_inc(void) { breathing_period_set(breathing_period + 1); } | ||
428 | |||
429 | void breathing_period_dec(void) { breathing_period_set(breathing_period - 1); } | ||
430 | |||
431 | /* To generate breathing curve in python: | ||
432 | * from math import sin, pi; [int(sin(x/128.0*pi)**4*255) for x in range(128)] | ||
433 | */ | ||
434 | static const uint8_t breathing_table[BREATHING_STEPS] PROGMEM = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 17, 20, 24, 28, 32, 36, 41, 46, 51, 57, 63, 70, 76, 83, 91, 98, 106, 113, 121, 129, 138, 146, 154, 162, 170, 178, 185, 193, 200, 207, 213, 220, 225, 231, 235, 240, 244, 247, 250, 252, 253, 254, 255, 254, 253, 252, 250, 247, 244, 240, 235, 231, 225, 220, 213, 207, 200, 193, 185, 178, 170, 162, 154, 146, 138, 129, 121, 113, 106, 98, 91, 83, 76, 70, 63, 57, 51, 46, 41, 36, 32, 28, 24, 20, 17, 15, 12, 10, 8, 6, 5, 4, 3, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; | ||
435 | |||
436 | // Use this before the cie_lightness function. | ||
437 | static inline uint16_t scale_backlight(uint16_t v) { return v / BACKLIGHT_LEVELS * get_backlight_level(); } | ||
438 | |||
439 | # ifdef BACKLIGHT_PWM_TIMER | ||
440 | void breathing_task(void) | ||
441 | # else | ||
442 | /* Assuming a 16MHz CPU clock and a timer that resets at 64k (ICR1), the following interrupt handler will run | ||
443 | * about 244 times per second. | ||
444 | */ | ||
445 | ISR(TIMERx_OVF_vect) | ||
446 | # endif | ||
447 | { | ||
448 | uint16_t interval = (uint16_t)breathing_period * 244 / BREATHING_STEPS; | ||
449 | // resetting after one period to prevent ugly reset at overflow. | ||
450 | breathing_counter = (breathing_counter + 1) % (breathing_period * 244); | ||
451 | uint8_t index = breathing_counter / interval % BREATHING_STEPS; | ||
452 | |||
453 | if (((breathing_halt == BREATHING_HALT_ON) && (index == BREATHING_STEPS / 2)) || ((breathing_halt == BREATHING_HALT_OFF) && (index == BREATHING_STEPS - 1))) { | ||
454 | breathing_interrupt_disable(); | ||
455 | } | ||
456 | |||
457 | set_pwm(cie_lightness(scale_backlight((uint16_t)pgm_read_byte(&breathing_table[index]) * 0x0101U))); | ||
458 | } | ||
459 | |||
460 | # endif // BACKLIGHT_BREATHING | ||
461 | |||
462 | __attribute__((weak)) void backlight_init_ports(void) { | ||
463 | // Setup backlight pin as output and output to on state. | ||
464 | FOR_EACH_LED(setPinOutput(backlight_pin); backlight_on(backlight_pin);) | ||
465 | |||
466 | // I could write a wall of text here to explain... but TL;DW | ||
467 | // Go read the ATmega32u4 datasheet. | ||
468 | // And this: http://blog.saikoled.com/post/43165849837/secret-konami-cheat-code-to-high-resolution-pwm-on | ||
469 | |||
470 | # ifdef BACKLIGHT_PWM_TIMER | ||
471 | // TimerX setup, Fast PWM mode count to TOP set in ICRx | ||
472 | TCCRxA = _BV(WGM11); // = 0b00000010; | ||
473 | // clock select clk/1 | ||
474 | TCCRxB = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001; | ||
475 | # else // hardware PWM | ||
476 | // Pin PB7 = OCR1C (Timer 1, Channel C) | ||
477 | // Compare Output Mode = Clear on compare match, Channel C = COM1C1=1 COM1C0=0 | ||
478 | // (i.e. start high, go low when counter matches.) | ||
479 | // WGM Mode 14 (Fast PWM) = WGM13=1 WGM12=1 WGM11=1 WGM10=0 | ||
480 | // Clock Select = clk/1 (no prescaling) = CS12=0 CS11=0 CS10=1 | ||
481 | |||
482 | /* | ||
483 | 14.8.3: | ||
484 | "In fast PWM mode, the compare units allow generation of PWM waveforms on the OCnx pins. Setting the COMnx1:0 bits to two will produce a non-inverted PWM [..]." | ||
485 | "In fast PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGMn3:0 = 5, 6, or 7), the value in ICRn (WGMn3:0 = 14), or the value in OCRnA (WGMn3:0 = 15)." | ||
486 | */ | ||
487 | TCCRxA = _BV(COMxx1) | _BV(WGM11); // = 0b00001010; | ||
488 | TCCRxB = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001; | ||
489 | # endif | ||
490 | // Use full 16-bit resolution. Counter counts to ICR1 before reset to 0. | ||
491 | ICRx = TIMER_TOP; | ||
492 | |||
493 | backlight_init(); | ||
494 | # ifdef BACKLIGHT_BREATHING | ||
495 | if (is_backlight_breathing()) { | ||
496 | breathing_enable(); | ||
497 | } | ||
498 | # endif | ||
499 | } | ||
500 | |||
501 | # endif // hardware backlight | ||
502 | |||
503 | #else // no backlight | ||
504 | |||
505 | __attribute__((weak)) void backlight_init_ports(void) {} | ||
506 | |||
507 | __attribute__((weak)) void backlight_set(uint8_t level) {} | ||
508 | |||
509 | #endif // backlight \ No newline at end of file | ||