/**
* @file
*
* @ingroup arm_beagle
*
* @brief BeagleBone Black PWM support definitions.
*/
/**
* Copyright (c) 2016 Punit Vara <punitvara@gmail.com>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
/** Some constants are taken from
* https://github.com/VegetableAvenger/BBBIOlib/blob/master/BBBio_lib/BBBiolib_PWMSS.h
*/
#ifndef LIBBSP_ARM_BEAGLE_BBB_PWM_H
#define LIBBSP_ARM_BEAGLE_BBB_PWM_H
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @brief BeagleBone Black PWM Macros.
*/
#define BBB_CONTROL_CONF_GPMC_AD(n) (0x800 + (n * 4))
#define BBB_CONTROL_CONF_LCD_DATA(n) (0x8a0 + (n * 4))
/**
* @brief The set of possible PWM subsystem module
*
* Enumerated type to define various instance of pwm module.
*/
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
/**
* @brief BeagleBone Black PWM API.
*/
/**
* @brief This function intilizes clock for pwm sub system.
*
* @param PWMSS_ID It is the instance number of EPWM of pwm sub system.
*
* @return true if successful
* @return false if not successful
*
**/
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);
/**
* @brief This API enables the particular PWM module.
*
* @param pwmid It is the instance number of EPWM of pwm sub system.
*
* @return true if successful
* @return false if fail
*
**/
bool beagle_pwm_enable(BBB_PWMSS pwmid);
/**
* @brief This API disables the particular PWM module.
*
* @param pwmid It is the instance number of EPWM of pwm sub system.
*
* @return true if successful
* @return false if fail
*
**/
bool beagle_pwm_disable(BBB_PWMSS pwmid);
/**
* @brief This function enables pinmuxing for PWM module.
*
* @param pin_no It is individual pin at which freuqency need to be generated.
* It should be according to pwm sub system.
*
* @param pwm_id It is the instance number of EPWM of pwmsubsystem.
*
* @return true if successful
* @return false if fail
*
**/
bool beagle_pwm_pinmux_setup(bbb_pwm_pin_t pin_no, BBB_PWMSS pwm_id);
/**
* @brief This function determines whether PWMSS-wide clocks enabled or not.
*
* @param pwmss_id It is the instance number of PWMSS which clocks need to be
* checked.
*
* @return true if successful
* @return false if fail
*
**/
bool beagle_pwmss_is_running(unsigned int pwmss_id);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* LIBBSP_ARM_BEAGLE_BBB_PWM_H */
