include/bsp/bbb-pwm.h

0001 /**
0002  * @file
0003  *
0004  * @ingroup arm_beagle
0005  *
0006  * @brief BeagleBone Black PWM support definitions.
0007  */
0008
0009 /*
0010  * SPDX-License-Identifier: BSD-2-Clause
0011  *
0012  * Copyright (c) 2016 Punit Vara <punitvara@gmail.com>
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036
0037 /** Some constants are taken from
0038  * https://github.com/VegetableAvenger/BBBIOlib/blob/master/BBBio_lib/BBBiolib_PWMSS.h
0039  */
0040
0041 #ifndef LIBBSP_ARM_BEAGLE_BBB_PWM_H
0042 #define LIBBSP_ARM_BEAGLE_BBB_PWM_H
0043
0044 #ifdef __cplusplus
0045 extern "C" {
0046 #endif /* __cplusplus */
0047
0048 /**
0049  * @brief  BeagleBone Black PWM Macros.
0050  */
0051 #define BBB_CONTROL_CONF_GPMC_AD(n)   (0x800 + (n * 4))
0052 #define BBB_CONTROL_CONF_LCD_DATA(n)   (0x8a0 + (n * 4))
0053
0054
0055 typedef enum{
0056   BBB_P8_13_2B = 3,
0057   BBB_P8_19_2A,
0058   BBB_P8_45_2A,
0059   BBB_P8_46_2B,
0060   BBB_P8_34_1B,
0061   BBB_P8_36_1A,
0062   BBB_P9_14_1A,
0063   BBB_P9_16_1B,
0064   BBB_P9_21_0B,
0065   BBB_P9_22_0A,
0066   BBB_P9_29_0B,
0067   BBB_P9_31_0A
0068 }bbb_pwm_pin_t;
0069
0070 #define BBB_P8_13_MUX_PWM 4
0071 #define BBB_P8_19_MUX_PWM 4
0072 #define BBB_P8_45_MUX_PWM 3
0073 #define BBB_P8_46_MUX_PWM 3
0074 #define BBB_P8_34_MUX_PWM 2
0075 #define BBB_P8_36_MUX_PWM 2
0076 #define BBB_P9_14_MUX_PWM 6
0077 #define BBB_P9_16_MUX_PWM 6
0078 #define BBB_P9_21_MUX_PWM 3
0079 #define BBB_P9_22_MUX_PWM 3
0080 #define BBB_P9_29_MUX_PWM 1
0081 #define BBB_P9_31_MUX_PWM 1
0082 #define BBB_PWM_FREQ_THRESHOLD 0.5f
0083
0084 /**
0085  * @brief  BeagleBone Black PWM API.
0086  */
0087
0088 /**
0089  * @brief This function intilizes clock for pwm sub system.
0090  *
0091  * @param PWMSS_ID It is the instance number of EPWM of pwm sub system.
0092  *
0093  * @return true if successful
0094  * @return false if not successful
0095  *
0096  **/
0097 bool beagle_pwm_init(BBB_PWMSS pwmss_id);
0098
0099 /* PWMSS setting
0100  *      set pulse argument of epwm module
0101  *
0102  *      @param pwm_id    : EPWMSS number , 0~2
0103  *      @param pwm_freq : frequency to be generated
0104  *      @param dutyA    : Duty Cycle(in percentage) in PWM channel A
0105  *      @param dutyB    : Duty Cycle(in percentage) in PWM channel B
0106  *
0107  *      @return         : 1 for success
0108  *      @return         : 0 for failed
0109  *
0110  *      @example        :  beagle_pwm_configure(0 , 50.0f , 50.0f , 25.0f);      // Generate 50HZ pwm in PWM0 ,
0111  *                                                                              // duty cycle is 50% for ePWM0A , 25% for ePWM0B
0112  *
0113  *      @Note :
0114  *              find an number nearst 65535 for TBPRD , to improve duty precision,
0115  *
0116  *              Using big TBPRD can increase the range of CMPA and CMPB ,
0117  *              and it means we can get better precision on duty cycle.
0118  *
0119  *              EX : 20.25% duty cycle
0120  *                  on TBPRD = 62500 , CMPA = 12656.25 ( .25 rejection) , real duty : 20.2496% (12656 /62500)
0121  *                  on TBPRD = 6250  , CMPA = 1265.625 ( .625 rejection), real duty : 20.24%   (1265 6250)
0122  *                  on TBPRD = 500   , CMPA = 101.25   ( .25 rejection) , real duty : 20.2%    (101/500)
0123  *
0124  *              Divisor = CLKDIV * HSPCLKDIV
0125  *                      1 TBPRD : 10 ns (default)
0126  *                      65535 TBPRD : 655350 ns
0127  *                      65535 TBPRD : 655350 * Divisor ns  = X TBPRD : Cycle
0128  *
0129  *              accrooding to that , we must find a Divisor value , let X nearest 65535 .
0130  *              so , Divisor must  Nearest Cycle/655350
0131  */
0132 int beagle_pwm_configure(BBB_PWMSS pwm_id, float pwm_freq, float duty_a, float duty_b);
0133
0134 /**
0135  * @brief   This API enables the particular PWM module.
0136  *
0137  * @param   pwmid  It is the instance number of EPWM of pwm sub system.
0138  *
0139  * @return  true if successful
0140  * @return  false if fail
0141  *
0142  **/
0143 bool beagle_pwm_enable(BBB_PWMSS pwmid);
0144
0145 /**
0146  * @brief   This API disables the particular PWM module.
0147  *
0148  * @param   pwmid  It is the instance number of EPWM of pwm sub system.
0149  *
0150  * @return  true if successful
0151  * @return  false if fail
0152  *
0153  **/
0154 bool beagle_pwm_disable(BBB_PWMSS pwmid);
0155
0156 /**
0157  * @brief   This function enables pinmuxing for PWM module.
0158  *
0159  * @param   pin_no  It is individual pin at which freuqency need to be generated.
0160  *                  It should be according to pwm sub system.
0161  *
0162  * @param   pwm_id  It is the instance number of EPWM of pwmsubsystem.
0163  *
0164  * @return  true if successful
0165  * @return  false if fail
0166  *
0167  **/
0168 bool beagle_pwm_pinmux_setup(bbb_pwm_pin_t pin_no, BBB_PWMSS pwm_id);
0169
0170 /**
0171  * @brief   This function determines whether PWMSS-wide clocks enabled or not.
0172  *
0173  * @param   pwmss_id  It is the instance number of PWMSS which clocks need to be
0174  *                    checked.
0175  *
0176  * @return  true if successful
0177  * @return  false if fail
0178  *
0179  **/
0180 bool beagle_pwmss_is_running(unsigned int pwmss_id);
0181
0182
0183 #ifdef __cplusplus
0184 }
0185 #endif /* __cplusplus */
0186
0187 #endif /* LIBBSP_ARM_BEAGLE_BBB_PWM_H */