source: rtems/c/src/lib/libbsp/arm/beagle/include/bbb-pwm.h @ 5e3096db

Last change on this file since 5e3096db was 5e3096db, checked in by Punit Vara <punitvara@…>, on Jul 4, 2016 at 6:05:43 PM

Beaglebone: Update PWM driver imported from BBBIO

This patch adapts the previously added Beaglebone PWM code from BBBIO to RTEMS.
This work was done in the context of the Google Summer of Code 2016, and further
patches will follow to improve the code quality and documentation.

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File size: 4.3 KB
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1/**
2 * @file
3 *
4 * @ingroup arm_beagle
5 *
6 * @brief BeagleBone Black BSP definitions.
7 */
8
9/**
10 * Copyright (c) 2016 Punit Vara <punitvara at gmail.com>
11 *
12 * The license and distribution terms for this file may be
13 * found in the file LICENSE in this distribution or at
14 * http://www.rtems.org/license/LICENSE.
15 */
16
17/** Some constants are taken from
18 * https://github.com/VegetableAvenger/BBBIOlib/blob/master/BBBio_lib/BBBiolib_PWMSS.h
19 */
20
21#ifndef LIBBSP_ARM_BEAGLE_BBB_PWM_H
22#define LIBBSP_ARM_BEAGLE_BBB_PWM_H
23
24#ifdef __cplusplus
25extern "C" {
26#endif /* __cplusplus */
27
28/**
29 * @brief  BeagleBone Black PWM Macros.
30 */
31#define BBB_CONTROL_CONF_GPMC_AD(n)   (0x800 + (n * 4))
32#define BBB_CONTROL_CONF_LCD_DATA(n)   (0x8a0 + (n * 4))
33
34#define BBB_PWMSS_COUNT       3
35#define BBB_PWMSS0  0
36#define BBB_PWMSS1  1 
37#define BBB_PWMSS2  2
38
39#define BBB_P8_13_2B  3
40#define BBB_P8_19_2A  4
41#define BBB_P8_45_2A  5
42#define BBB_P8_46_2B  6
43#define BBB_P8_34_1B  7
44#define BBB_P8_36_1A  8
45#define BBB_P9_14_1A  9
46#define BBB_P9_16_1B  10
47#define BBB_P9_21_0B  11
48#define BBB_P9_22_0A  12
49#define BBB_P9_29_0B  13
50#define BBB_P9_31_0A  14
51
52#define BBB_MUX0      0
53#define BBB_MUX1      1
54#define BBB_MUX2      2
55#define BBB_MUX3      3
56#define BBB_MUX4      4
57#define BBB_MUX5      5
58#define BBB_MUX6      6
59#define BBB_MUX7      7
60
61#define BBB_EPWM1     1
62#define BBB_EPWM2     2
63#define BBB_EPWM0     0
64
65/**
66 * @brief  BeagleBone Black PWM API.
67 */
68
69/**
70 * @brief This function intilize clock and pinmuxing for pwm sub system.
71 *
72 * @param PWMSS_ID It is the instance number of EPWM of pwm sub system.
73 *
74 * @return true if successful
75 * @return false if not successful
76 *
77 **/
78bool beagle_pwm_init(uint32_t pwmss_id);
79
80/* PWMSS setting
81 *      set pulse argument of epwm module
82 *
83 *      @param pwm_id    : EPWMSS number , 0~2
84 *      @param pwm_freq : frequency to be generated
85 *      @param dutyA    : Duty Cycle in ePWM A
86 *      @param dutyB    : Duty Cycle in ePWM B
87 *
88 *      @return         : 1 for success
89 *      @return         : 0 for failed
90 *
91 *      @example        :  PWMSS_Setting(0 , 50.0f , 50.0f , 25.0f);      // Generate 50HZ pwm in PWM0 ,
92 *                                                                              // duty cycle is 50% for ePWM0A , 25% for ePWM0B
93 *
94 *      @Note :
95 *              find an number nearst 65535 for TBPRD , to improve duty precision,
96 *
97 *              Using big TBPRD can increase the range of CMPA and CMPB ,
98 *              and it means we can get better precision on duty cycle.
99 *
100 *              EX : 20.25% duty cycle
101 *                  on TBPRD = 62500 , CMPA = 12656.25 ( .25 rejection) , real duty : 20.2496% (12656 /62500)
102 *                  on TBPRD = 6250  , CMPA = 1265.625 ( .625 rejection), real duty : 20.24%   (1265 6250)
103 *                  on TBPRD = 500   , CMPA = 101.25   ( .25 rejection) , real duty : 20.2%    (101/500)
104 *
105 *              Divisor = CLKDIV * HSPCLKDIV
106 *                      1 TBPRD : 10 ns (default)
107 *                      65535 TBPRD : 655350 ns
108 *                      65535 TBPRD : 655350 * Divisor ns  = X TBPRD : Cyclens
109 *
110 *              accrooding to that , we must find a Divisor value , let X nearest 65535 .
111 *              so , Divisor must  Nearest Cyclens/655350
112 */
113int beagle_pwmss_setting(uint32_t pwm_id, float pwm_freq, float dutyA, float dutyB);
114
115/**
116 * @brief   This API enables the particular PWM module.
117 *
118 * @param   pwmid  It is the instance number of EPWM of pwm sub system.
119 *
120 * @return  true if successful
121 * @return  false if fail
122 *
123 **/
124bool beagle_ehrpwm_enable(uint32_t pwmid);
125
126/**
127 * @brief   This API disables the HR sub-module.
128 *
129 * @param   pwmid  It is the instance number of EPWM of pwm sub system.
130 *
131 * @return  true if successful
132 * @return  false if fail
133 *
134 **/
135bool beagle_ehrpwm_disable(uint32_t pwmid);
136
137/**
138 * @brief   This function Enables pinmuxing for PWM module.
139 *
140 * @param   pin_no  It is individual pin at which freuqency need to be generated.
141 *                  It should be according to pwm sub system.
142 *
143 * @param   pwm_id  It is the instance number of EPWM of pwmsubsystem.
144 *
145 * @return  true if successful
146 * @return  false if fail
147 *
148 **/
149bool beagle_epwm_pinmux_setup(uint32_t pin_no, uint32_t pwm_id);
150
151#ifdef __cplusplus
152}
153#endif /* __cplusplus */
154
155#endif /* LIBBSP_ARM_BEAGLE_BBB_PWM_H */
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