From aef7a2973e223bbfc813c97b6244edc403051a55 Mon Sep 17 00:00:00 2001 From: flabbergast Date: Sun, 18 Oct 2015 11:37:27 +0100 Subject: [PATCH] Chibios: Add breathing sleep LED on Kinetis MCUs. --- tmk_core/common/chibios/sleep_led.c | 143 ++++++++++++++++++++++++++-- 1 file changed, 136 insertions(+), 7 deletions(-) diff --git a/tmk_core/common/chibios/sleep_led.c b/tmk_core/common/chibios/sleep_led.c index fad7ac04..d9cdeba1 100644 --- a/tmk_core/common/chibios/sleep_led.c +++ b/tmk_core/common/chibios/sleep_led.c @@ -1,23 +1,152 @@ #include "ch.h" +#include "hal.h" #include "led.h" #include "sleep_led.h" +#if defined(KL2x) || defined(K20x) /* platform selection: familiar Kinetis chips */ +/* All right, we go the "software" way: LP timer, toggle LED in interrupt. + * Based on hasu's code for AVRs. + */ + +/* Breathing Sleep LED brighness(PWM On period) table + * (64[steps] * 4[duration]) / 64[PWM periods/s] = 4 second breath cycle + * + * http://www.wolframalpha.com/input/?i=%28sin%28+x%2F64*pi%29**8+*+255%2C+x%3D0+to+63 + * (0..63).each {|x| p ((sin(x/64.0*PI)**8)*255).to_i } + */ +static const uint8_t breathing_table[64] = { +0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 4, 6, 10, +15, 23, 32, 44, 58, 74, 93, 113, 135, 157, 179, 199, 218, 233, 245, 252, +255, 252, 245, 233, 218, 199, 179, 157, 135, 113, 93, 74, 58, 44, 32, 23, +15, 10, 6, 4, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 +}; + +/* LP Timer interrupt handler */ +OSAL_IRQ_HANDLER(KINETIS_LPTMR0_IRQ_VECTOR) { + OSAL_IRQ_PROLOGUE(); + + /* Software PWM + * timer:1111 1111 1111 1111 + * \_____/\/ \_______/____ count(0-255) + * \ \______________ duration of step(4) + * \__________________ index of step table(0-63) + */ + + // this works for cca 65536 irqs/sec + static union { + uint16_t row; + struct { + uint8_t count:8; + uint8_t duration:2; + uint8_t index:6; + } pwm; + } timer = { .row = 0 }; + + timer.row++; + + // LED on + if (timer.pwm.count == 0) { + led_set(1<CSR |= LPTMRx_CSR_TCF; + + OSAL_IRQ_EPILOGUE(); +} + +/* LPTMR clock options */ +#define LPTMR_CLOCK_MCGIRCLK 0 /* 4MHz clock */ +#define LPTMR_CLOCK_LPO 1 /* 1kHz clock */ +#define LPTMR_CLOCK_ERCLK32K 2 +#define LPTMR_CLOCK_OSCERCLK 3 /* output from OSC */ + +/* Work around inconsistencies in Freescale naming */ +#if !defined(SIM_SCGC5_LPTMR) +#define SIM_SCGC5_LPTMR SIM_SCGC5_LPTIMER +#endif + +/* Initialise the timer */ void sleep_led_init(void) { - // we could go the 'software way' -- just enable *some* timer - // and go with callbacks - // or we could go the 'hardware way' -- and use timer output to - // pins directly + /* Make sure the clock to the LPTMR is enabled */ + SIM->SCGC5 |= SIM_SCGC5_LPTMR; + /* Reset LPTMR settings */ + LPTMR0->CSR = 0; + /* Set the compare value */ + LPTMR0->CMR = 1; // trigger on counter value (i.e. every time) + /* Set up clock source and prescaler */ + /* Software PWM + * ______ ______ __ + * | ON |___OFF___| ON |___OFF___| .... + * |<-------------->|<-------------->|<- .... + * PWM period PWM period + * + * R interrupts/period[resolution] + * F periods/second[frequency] + * R * F interrupts/second + */ + /* === OPTION 1 === */ + // for 1kHz LPO + // No prescaler => 1024 irqs/sec + // LPTMR0->PSR = LPTMRx_PSR_PCS(LPTMR_CLOCK_LPO)|LPTMRx_PSR_PBYP; + /* === OPTION 2 === */ + // for nMHz IRC (n=4 on KL25Z, KL26Z and K20x; n=2 or 8 on KL27Z) + MCG->C2 |= MCG_C2_IRCS; // fast (4MHz) internal ref clock + #if defined(KL27Z) // divide the 8MHz IRC by 2, to have the same MCGIRCLK speed as others + MCG->MC |= MCG_MC_LIRC_DIV2_DIV2; + #endif /* KL27Z */ + MCG->C1 |= MCG_C1_IRCLKEN; // enable internal ref clock + // to work in stop mode, also MCG_C1_IREFSTEN + // Divide 4MHz by 2^N (N=5) => 62500 irqs/sec => + // => approx F=61, R=256, duration = 4 + LPTMR0->PSR = LPTMRx_PSR_PCS(LPTMR_CLOCK_MCGIRCLK)|LPTMRx_PSR_PRESCALE(5); + /* === OPTION 3 === */ + // for OSC output (external crystal), usually 8MHz or 16MHz + // OSC0->CR |= OSC_CR_ERCLKEN; // enable ext ref clock + // to work in stop mode, also OSC_CR_EREFSTEN + // Divide by 2^N + // LPTMR0->PSR = LPTMRx_PSR_PCS(LPTMR_CLOCK_OSCERCLK)|LPTMRx_PSR_PRESCALE(7); + /* === END OPTIONS === */ + /* Interrupt on TCF set (compare flag) */ + nvicEnableVector(LPTMR0_IRQn, 2); // vector, priority + LPTMR0->CSR |= LPTMRx_CSR_TIE; } void sleep_led_enable(void) { - led_set(1<CSR |= LPTMRx_CSR_TEN; } void sleep_led_disable(void) { - led_set(0); + /* Disable the timer */ + LPTMR0->CSR &= ~LPTMRx_CSR_TEN; } void sleep_led_toggle(void) { - // not working yet, state not saved anywhere currently + /* Toggle the timer */ + LPTMR0->CSR ^= LPTMRx_CSR_TEN; } + +#else /* platform selection: not on familiar Kinetis chips */ + +void sleep_led_init(void) { +} + +void sleep_led_enable(void) { + led_set(1<