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#include <ch.h>
#include <hal.h>
#include "led.h"
#include "sleep_led.h"
/* All right, we go the "software" way: timer, toggle LED in interrupt.
* Based on hasu's code for AVRs.
* Use LP timer on Kinetises, TIM14 on STM32F0.
*/
#ifndef SLEEP_LED_GPT_DRIVER
# if defined(STM32F0XX)
# define SLEEP_LED_GPT_DRIVER GPTD14
# endif
#endif
#if defined(KL2x) || defined(K20x) || defined(SLEEP_LED_GPT_DRIVER) /* common parts for timers/interrupts */
/* 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};
void sleep_led_timer_callback(void) {
/* 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 << USB_LED_CAPS_LOCK);
}
// LED off
if (timer.pwm.count == breathing_table[timer.pwm.index]) {
led_set(0);
}
}
#endif /* common parts for known platforms */
#if defined(KL2x) || defined(K20x) /* platform selection: familiar Kinetis chips */
/* Use Low Power Timer (LPTMR) */
# define TIMER_INTERRUPT_VECTOR KINETIS_LPTMR0_IRQ_VECTOR
# define RESET_COUNTER LPTMR0->CSR |= LPTMRx_CSR_TCF
/* LPTMR clock options */
# define LPTMR_CLOCK_MCGIRCLK 0 /* 4MHz clock */
# define LPTMR_CLOCK_LPO 1 /* 1kHz clock */
# define LPTMR_CLOCK_ERCLK32K 2 /* external 32kHz crystal */
# 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
/* interrupt handler */
OSAL_IRQ_HANDLER(TIMER_INTERRUPT_VECTOR) {
OSAL_IRQ_PROLOGUE();
sleep_led_timer_callback();
/* Reset the counter */
RESET_COUNTER;
OSAL_IRQ_EPILOGUE();
}
/* Initialise the timer */
void sleep_led_init(void) {
/* 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 = 0; // 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 === */
# if 0
// 1kHz LPO
// No prescaler => 1024 irqs/sec
// Note: this is too slow for a smooth breathe
LPTMR0->PSR = LPTMRx_PSR_PCS(LPTMR_CLOCK_LPO)|LPTMRx_PSR_PBYP;
# endif /* OPTION 1 */
/* === OPTION 2 === */
# if 1
// 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(KL27) // divide the 8MHz IRC by 2, to have the same MCGIRCLK speed as others
MCG->MC |= MCG_MC_LIRC_DIV2_DIV2;
# endif /* KL27 */
MCG->C1 |= MCG_C1_IRCLKEN; // enable internal ref clock
// to work in stop mode, also MCG_C1_IREFSTEN
// Divide 4MHz by 2^N (N=6) => 62500 irqs/sec =>
// => approx F=61, R=256, duration = 4
LPTMR0->PSR = LPTMRx_PSR_PCS(LPTMR_CLOCK_MCGIRCLK) | LPTMRx_PSR_PRESCALE(6);
# endif /* OPTION 2 */
/* === OPTION 3 === */
# if 0
// 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);
# endif /* OPTION 3 */
/* === END OPTIONS === */
/* Interrupt on TCF set (compare flag) */
nvicEnableVector(LPTMR0_IRQn, 2); // vector, priority
LPTMR0->CSR |= LPTMRx_CSR_TIE;
}
void sleep_led_enable(void) {
/* Enable the timer */
LPTMR0->CSR |= LPTMRx_CSR_TEN;
}
void sleep_led_disable(void) {
/* Disable the timer */
LPTMR0->CSR &= ~LPTMRx_CSR_TEN;
}
void sleep_led_toggle(void) {
/* Toggle the timer */
LPTMR0->CSR ^= LPTMRx_CSR_TEN;
}
#elif defined(SLEEP_LED_GPT_DRIVER)
static void gptTimerCallback(GPTDriver *gptp) {
(void)gptp;
sleep_led_timer_callback();
}
static const GPTConfig gptcfg = {1000000, gptTimerCallback, 0, 0};
/* Initialise the timer */
void sleep_led_init(void) { gptStart(&SLEEP_LED_GPT_DRIVER, &gptcfg); }
void sleep_led_enable(void) { gptStartContinuous(&SLEEP_LED_GPT_DRIVER, gptcfg.frequency / 0xFFFF); }
void sleep_led_disable(void) { gptStopTimer(&SLEEP_LED_GPT_DRIVER); }
void sleep_led_toggle(void) { (SLEEP_LED_GPT_DRIVER.state == GPT_READY) ? sleep_led_enable() : sleep_led_disable(); }
#else /* platform selection: not on familiar chips */
void sleep_led_init(void) {}
void sleep_led_enable(void) { led_set(1 << USB_LED_CAPS_LOCK); }
void sleep_led_disable(void) { led_set(0); }
void sleep_led_toggle(void) {
// not implemented
}
#endif /* platform selection */
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