bbb-pwm.h

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#ifndef LIBBSP_ARM_BEAGLE_BBB_PWM_H
#define LIBBSP_ARM_BEAGLE_BBB_PWM_H
 
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
 
#define BBB_CONTROL_CONF_GPMC_AD(n)   (0x800 + (n * 4))
#define BBB_CONTROL_CONF_LCD_DATA(n)   (0x8a0 + (n * 4))
 
typedef enum{
  BBB_PWMSS0 = 0,
  BBB_PWMSS1,
  BBB_PWMSS2,
  BBB_PWMSS_COUNT
}BBB_PWMSS;
 
typedef enum{
  BBB_P8_13_2B = 3,
  BBB_P8_19_2A,
  BBB_P8_45_2A,
  BBB_P8_46_2B,
  BBB_P8_34_1B,
  BBB_P8_36_1A,
  BBB_P9_14_1A,
  BBB_P9_16_1B,
  BBB_P9_21_0B,
  BBB_P9_22_0A,
  BBB_P9_29_0B,
  BBB_P9_31_0A
}bbb_pwm_pin_t;
 
#define BBB_P8_13_MUX_PWM 4 
#define BBB_P8_19_MUX_PWM 4
#define BBB_P8_45_MUX_PWM 3
#define BBB_P8_46_MUX_PWM 3
#define BBB_P8_34_MUX_PWM 2
#define BBB_P8_36_MUX_PWM 2
#define BBB_P9_14_MUX_PWM 6
#define BBB_P9_16_MUX_PWM 6
#define BBB_P9_21_MUX_PWM 3
#define BBB_P9_22_MUX_PWM 3
#define BBB_P9_29_MUX_PWM 1
#define BBB_P9_31_MUX_PWM 1
#define BBB_PWM_FREQ_THRESHOLD 0.5f
 
bool beagle_pwm_init(BBB_PWMSS pwmss_id);
 
/* PWMSS setting
 *      set pulse argument of epwm module
 *
 *      @param pwm_id    : EPWMSS number , 0~2
 *      @param pwm_freq : frequency to be generated
 *      @param dutyA    : Duty Cycle(in percentage) in PWM channel A
 *      @param dutyB    : Duty Cycle(in percentage) in PWM channel B
 *
 *      @return         : 1 for success
 *      @return         : 0 for failed
 *
 *      @example        :  beagle_pwm_configure(0 , 50.0f , 50.0f , 25.0f);      // Generate 50HZ pwm in PWM0 ,
 *                                                                              // duty cycle is 50% for ePWM0A , 25% for ePWM0B
 *
 *      @Note :
 *              find an number nearst 65535 for TBPRD , to improve duty precision,
 *
 *              Using big TBPRD can increase the range of CMPA and CMPB ,
 *              and it means we can get better precision on duty cycle.
 *
 *              EX : 20.25% duty cycle
 *                  on TBPRD = 62500 , CMPA = 12656.25 ( .25 rejection) , real duty : 20.2496% (12656 /62500)
 *                  on TBPRD = 6250  , CMPA = 1265.625 ( .625 rejection), real duty : 20.24%   (1265 6250)
 *                  on TBPRD = 500   , CMPA = 101.25   ( .25 rejection) , real duty : 20.2%    (101/500)
 *
 *              Divisor = CLKDIV * HSPCLKDIV
 *                      1 TBPRD : 10 ns (default)
 *                      65535 TBPRD : 655350 ns
 *                      65535 TBPRD : 655350 * Divisor ns  = X TBPRD : Cycle
 *
 *              accrooding to that , we must find a Divisor value , let X nearest 65535 .
 *              so , Divisor must  Nearest Cycle/655350
 */
int beagle_pwm_configure(BBB_PWMSS pwm_id, float pwm_freq, float duty_a, float duty_b);
 
bool beagle_pwm_enable(BBB_PWMSS pwmid);
 
bool beagle_pwm_disable(BBB_PWMSS pwmid);
 
bool beagle_pwm_pinmux_setup(bbb_pwm_pin_t pin_no, BBB_PWMSS pwm_id);
 
bool beagle_pwmss_is_running(unsigned int pwmss_id);
 
 
#ifdef __cplusplus
}
#endif /* __cplusplus */
 
#endif /* LIBBSP_ARM_BEAGLE_BBB_PWM_H */