Allow any clock >= 8 MHz on Teensy 3.x

Author: PaulStoffregen

IRremoteInt.h

@@ -526,19 +526,18 @@ EXTERN volatile irparams_t irparams;
 #define ISR(f) void f(void)
 
 //-----------------
-#if (F_BUS == 48000000)
-#	define CMT_PPS_VAL 5
-#else
-#	define CMT_PPS_VAL 2
+#define CMT_PPS_DIV ((F_BUS + 7999999) / 8000000)
+#if F_BUS < 8000000
+#error IRremote requires at least 8 MHz on Teensy 3.x
 #endif
 
 //-----------------
 #define TIMER_CONFIG_KHZ(val) ({ \
 SIM_SCGC4 |= SIM_SCGC4_CMT; \
 SIM_SOPT2 |= SIM_SOPT2_PTD7PAD; \
-CMT_PPS = CMT_PPS_VAL;  \
-CMT_CGH1 = 2667 / val;  \
-CMT_CGL1 = 5333 / val;  \
+CMT_PPS = CMT_PPS_DIV - 1; \
+CMT_CGH1 = ((F_BUS / CMT_PPS_DIV / 3000) + ((val)/2)) / (val); \
+CMT_CGL1 = ((F_BUS / CMT_PPS_DIV / 1500) + ((val)/2)) / (val); \
 CMT_CMD1 = 0; \
 CMT_CMD2 = 30; \
 CMT_CMD3 = 0; \
@@ -549,13 +548,13 @@ EXTERN volatile irparams_t irparams;
 
 #define TIMER_CONFIG_NORMAL() ({ \
 SIM_SCGC4 |= SIM_SCGC4_CMT; \
-CMT_PPS = CMT_PPS_VAL;  \
+CMT_PPS = CMT_PPS_DIV - 1; \
 CMT_CGH1 = 1; \
 CMT_CGL1 = 1; \
 CMT_CMD1 = 0; \
 CMT_CMD2 = 30; \
 CMT_CMD3 = 0; \
-CMT_CMD4 = 19;  \
+CMT_CMD4 = (F_BUS / 160000 + CMT_PPS_DIV / 2) / CMT_PPS_DIV - 31; \
 CMT_OC = 0; \
 CMT_MSC = 0x03; \
 })