wiringpi pwm 라이브러리 분석?

데이터 시트상으로는 PWM 1과 PWM 2 채널 독립적으로

모드를 설정하여 사용이 가능해야 하나...

wiringPi에서는 편의상.. 걍 묶어 버렸다!!!!

wiringPi/wiringPi $ vi wiringPi.c

void pwmSetMode (int mode) {   if ((wiringPiMode == WPI_MODE_PINS) || (wiringPiMode == WPI_MODE_PHYS) || (wiringPiMode == WPI_MODE_GPIO))   {     if (mode == PWM_MODE_MS)       *(pwm + PWM_CONTROL) = PWM0_ENABLE | PWM1_ENABLE | PWM0_MS_MODE | PWM1_MS_MODE ;     else       *(pwm + PWM_CONTROL) = PWM0_ENABLE | PWM1_ENABLE ;   } } void pwmSetRange (unsigned int range) {   if ((wiringPiMode == WPI_MODE_PINS) || (wiringPiMode == WPI_MODE_PHYS) || (wiringPiMode == WPI_MODE_GPIO))   {     *(pwm + PWM0_RANGE) = range ; delayMicroseconds (10) ;     *(pwm + PWM1_RANGE) = range ; delayMicroseconds (10) ;   } } void pwmSetClock (int divisor) {   uint32_t pwm_control ;   divisor &= 4095 ;   if ((wiringPiMode == WPI_MODE_PINS) || (wiringPiMode == WPI_MODE_PHYS) || (wiringPiMode == WPI_MODE_GPIO))   {     if (wiringPiDebug)       printf ("Setting to: %d. Current: 0x%08X\n", divisor, *(clk + PWMCLK_DIV)) ;     pwm_control = *(pwm + PWM_CONTROL) ;                // preserve PWM_CONTROL // We need to stop PWM prior to stopping PWM clock in MS mode otherwise BUSY // stays high.     *(pwm + PWM_CONTROL) = 0 ;                          // Stop PWM // Stop PWM clock before changing divisor. The delay after this does need to // this big (95uS occasionally fails, 100uS OK), it's almost as though the BUSY // flag is not working properly in balanced mode. Without the delay when DIV is // adjusted the clock sometimes switches to very slow, once slow further DIV // adjustments do nothing and it's difficult to get out of this mode.     *(clk + PWMCLK_CNTL) = BCM_PASSWORD | 0x01 ;        // Stop PWM Clock       delayMicroseconds (110) ;                 // prevents clock going sloooow     while ((*(clk + PWMCLK_CNTL) & 0x80) != 0)  // Wait for clock to be !BUSY       delayMicroseconds (1) ;     *(clk + PWMCLK_DIV)  = BCM_PASSWORD | (divisor << 12) ;     *(clk + PWMCLK_CNTL) = BCM_PASSWORD | 0x11 ;        // Start PWM clock     *(pwm + PWM_CONTROL) = pwm_control ;                // restore PWM_CONTROL     if (wiringPiDebug)       printf ("Set     to: %d. Now    : 0x%08X\n", divisor, *(clk + PWMCLK_DIV)) ;   } }