1 files changed, 192 insertions, 0 deletions

diff --git a/platforms/chibios/sleep_led.c b/platforms/chibios/sleep_led.c
new file mode 100644
index 000000000..477056a45
--- /dev/null
+++ b/platforms/chibios/sleep_led.c
@@ -0,0 +1,192 @@
+#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 */