MacroRat / MouseCode

Mouse code for the MacroRat

Dependencies:   ITG3200 QEI

mbed-dev/targets/TARGET_NXP/TARGET_LPC82X/pwmout_api.c@18:6a4db94011d3, 2017-05-14 (annotated)

Committer:
sahilmgandhi
Date:
Sun May 14 23:18:57 2017 +0000
Revision:
18:6a4db94011d3
Publishing again

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sahilmgandhi 18:6a4db94011d3 1 /* mbed Microcontroller Library
sahilmgandhi 18:6a4db94011d3 2 * Copyright (c) 2006-2013 ARM Limited
sahilmgandhi 18:6a4db94011d3 3 *
sahilmgandhi 18:6a4db94011d3 4 * Licensed under the Apache License, Version 2.0 (the "License");
sahilmgandhi 18:6a4db94011d3 5 * you may not use this file except in compliance with the License.
sahilmgandhi 18:6a4db94011d3 6 * You may obtain a copy of the License at
sahilmgandhi 18:6a4db94011d3 7 *
sahilmgandhi 18:6a4db94011d3 8 * http://www.apache.org/licenses/LICENSE-2.0
sahilmgandhi 18:6a4db94011d3 9 *
sahilmgandhi 18:6a4db94011d3 10 * Unless required by applicable law or agreed to in writing, software
sahilmgandhi 18:6a4db94011d3 11 * distributed under the License is distributed on an "AS IS" BASIS,
sahilmgandhi 18:6a4db94011d3 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
sahilmgandhi 18:6a4db94011d3 13 * See the License for the specific language governing permissions and
sahilmgandhi 18:6a4db94011d3 14 * limitations under the License.
sahilmgandhi 18:6a4db94011d3 15 */
sahilmgandhi 18:6a4db94011d3 16 #include "mbed_assert.h"
sahilmgandhi 18:6a4db94011d3 17 #include "pwmout_api.h"
sahilmgandhi 18:6a4db94011d3 18 #include "cmsis.h"
sahilmgandhi 18:6a4db94011d3 19 #include "pinmap.h"
sahilmgandhi 18:6a4db94011d3 20 #include "mbed_error.h"
sahilmgandhi 18:6a4db94011d3 21
sahilmgandhi 18:6a4db94011d3 22 #if DEVICE_PWMOUT
sahilmgandhi 18:6a4db94011d3 23
sahilmgandhi 18:6a4db94011d3 24 // bit flags for used SCTs
sahilmgandhi 18:6a4db94011d3 25 static unsigned char sct_used = 0;
sahilmgandhi 18:6a4db94011d3 26
sahilmgandhi 18:6a4db94011d3 27 static int get_available_sct()
sahilmgandhi 18:6a4db94011d3 28 {
sahilmgandhi 18:6a4db94011d3 29 int i;
sahilmgandhi 18:6a4db94011d3 30 for (i = 0; i < 4; i++) {
sahilmgandhi 18:6a4db94011d3 31 if ((sct_used & (1 << i)) == 0)
sahilmgandhi 18:6a4db94011d3 32 return i;
sahilmgandhi 18:6a4db94011d3 33 }
sahilmgandhi 18:6a4db94011d3 34 return -1;
sahilmgandhi 18:6a4db94011d3 35 }
sahilmgandhi 18:6a4db94011d3 36
sahilmgandhi 18:6a4db94011d3 37 void pwmout_init(pwmout_t* obj, PinName pin)
sahilmgandhi 18:6a4db94011d3 38 {
sahilmgandhi 18:6a4db94011d3 39 MBED_ASSERT(pin != (PinName)NC);
sahilmgandhi 18:6a4db94011d3 40
sahilmgandhi 18:6a4db94011d3 41 int sct_n = get_available_sct();
sahilmgandhi 18:6a4db94011d3 42 if (sct_n == -1) {
sahilmgandhi 18:6a4db94011d3 43 error("No available SCT");
sahilmgandhi 18:6a4db94011d3 44 }
sahilmgandhi 18:6a4db94011d3 45
sahilmgandhi 18:6a4db94011d3 46 sct_used |= (1 << sct_n);
sahilmgandhi 18:6a4db94011d3 47
sahilmgandhi 18:6a4db94011d3 48 obj->pwm = (LPC_SCT_Type*)LPC_SCT;
sahilmgandhi 18:6a4db94011d3 49 obj->pwm_ch = sct_n;
sahilmgandhi 18:6a4db94011d3 50
sahilmgandhi 18:6a4db94011d3 51 LPC_SCT_Type* pwm = obj->pwm;
sahilmgandhi 18:6a4db94011d3 52
sahilmgandhi 18:6a4db94011d3 53 // Enable the SCT clock
sahilmgandhi 18:6a4db94011d3 54 LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 8);
sahilmgandhi 18:6a4db94011d3 55
sahilmgandhi 18:6a4db94011d3 56 // Clear peripheral reset the SCT:
sahilmgandhi 18:6a4db94011d3 57 LPC_SYSCON->PRESETCTRL |= (1 << 8);
sahilmgandhi 18:6a4db94011d3 58
sahilmgandhi 18:6a4db94011d3 59 switch(sct_n) {
sahilmgandhi 18:6a4db94011d3 60 case 0:
sahilmgandhi 18:6a4db94011d3 61 // SCT_OUT0
sahilmgandhi 18:6a4db94011d3 62 LPC_SWM->PINASSIGN[7] &= ~0xFF000000;
sahilmgandhi 18:6a4db94011d3 63 LPC_SWM->PINASSIGN[7] |= ((pin >> PIN_SHIFT) << 24);
sahilmgandhi 18:6a4db94011d3 64 break;
sahilmgandhi 18:6a4db94011d3 65 case 1:
sahilmgandhi 18:6a4db94011d3 66 // SCT_OUT1
sahilmgandhi 18:6a4db94011d3 67 LPC_SWM->PINASSIGN[8] &= ~0x000000FF;
sahilmgandhi 18:6a4db94011d3 68 LPC_SWM->PINASSIGN[8] |= (pin >> PIN_SHIFT);
sahilmgandhi 18:6a4db94011d3 69 break;
sahilmgandhi 18:6a4db94011d3 70 case 2:
sahilmgandhi 18:6a4db94011d3 71 // SCT2_OUT2
sahilmgandhi 18:6a4db94011d3 72 LPC_SWM->PINASSIGN[8] &= ~0x0000FF00;
sahilmgandhi 18:6a4db94011d3 73 LPC_SWM->PINASSIGN[8] |= ((pin >> PIN_SHIFT) << 8);
sahilmgandhi 18:6a4db94011d3 74 break;
sahilmgandhi 18:6a4db94011d3 75 case 3:
sahilmgandhi 18:6a4db94011d3 76 // SCT3_OUT3
sahilmgandhi 18:6a4db94011d3 77 LPC_SWM->PINASSIGN[8] &= ~0x00FF0000;
sahilmgandhi 18:6a4db94011d3 78 LPC_SWM->PINASSIGN[8] |= ((pin >> PIN_SHIFT) << 16);
sahilmgandhi 18:6a4db94011d3 79 break;
sahilmgandhi 18:6a4db94011d3 80 default:
sahilmgandhi 18:6a4db94011d3 81 break;
sahilmgandhi 18:6a4db94011d3 82 }
sahilmgandhi 18:6a4db94011d3 83
sahilmgandhi 18:6a4db94011d3 84 // Unified 32-bit counter, autolimit
sahilmgandhi 18:6a4db94011d3 85 pwm->CONFIG |= ((0x3 << 17) | 0x01);
sahilmgandhi 18:6a4db94011d3 86
sahilmgandhi 18:6a4db94011d3 87 // halt and clear the counter
sahilmgandhi 18:6a4db94011d3 88 pwm->CTRL |= (1 << 2) | (1 << 3);
sahilmgandhi 18:6a4db94011d3 89
sahilmgandhi 18:6a4db94011d3 90 // System Clock -> us_ticker (1)MHz
sahilmgandhi 18:6a4db94011d3 91 pwm->CTRL &= ~(0x7F << 5);
sahilmgandhi 18:6a4db94011d3 92 pwm->CTRL |= (((SystemCoreClock/1000000 - 1) & 0x7F) << 5);
sahilmgandhi 18:6a4db94011d3 93
sahilmgandhi 18:6a4db94011d3 94 // Set event number
sahilmgandhi 18:6a4db94011d3 95 pwm->OUT[sct_n].SET = (1 << ((sct_n * 2) + 0));
sahilmgandhi 18:6a4db94011d3 96 pwm->OUT[sct_n].CLR = (1 << ((sct_n * 2) + 1));
sahilmgandhi 18:6a4db94011d3 97
sahilmgandhi 18:6a4db94011d3 98 pwm->EVENT[(sct_n * 2) + 0].CTRL = (1 << 12) | ((sct_n * 2) + 0); // match event
sahilmgandhi 18:6a4db94011d3 99 pwm->EVENT[(sct_n * 2) + 0].STATE = 0xFFFFFFFF;
sahilmgandhi 18:6a4db94011d3 100 pwm->EVENT[(sct_n * 2) + 1].CTRL = (1 << 12) | ((sct_n * 2) + 1);
sahilmgandhi 18:6a4db94011d3 101 pwm->EVENT[(sct_n * 2) + 1].STATE = 0xFFFFFFFF;
sahilmgandhi 18:6a4db94011d3 102
sahilmgandhi 18:6a4db94011d3 103 // default to 20ms: standard for servos, and fine for e.g. brightness control
sahilmgandhi 18:6a4db94011d3 104 pwmout_period_ms(obj, 20);
sahilmgandhi 18:6a4db94011d3 105 pwmout_write (obj, 0);
sahilmgandhi 18:6a4db94011d3 106 }
sahilmgandhi 18:6a4db94011d3 107
sahilmgandhi 18:6a4db94011d3 108 void pwmout_free(pwmout_t* obj)
sahilmgandhi 18:6a4db94011d3 109 {
sahilmgandhi 18:6a4db94011d3 110 // Disable the SCT clock
sahilmgandhi 18:6a4db94011d3 111 LPC_SYSCON->SYSAHBCLKCTRL &= ~(1 << 8);
sahilmgandhi 18:6a4db94011d3 112 sct_used &= ~(1 << obj->pwm_ch);
sahilmgandhi 18:6a4db94011d3 113 }
sahilmgandhi 18:6a4db94011d3 114
sahilmgandhi 18:6a4db94011d3 115 void pwmout_write(pwmout_t* obj, float value)
sahilmgandhi 18:6a4db94011d3 116 {
sahilmgandhi 18:6a4db94011d3 117 if (value < 0.0f) {
sahilmgandhi 18:6a4db94011d3 118 value = 0.0;
sahilmgandhi 18:6a4db94011d3 119 } else if (value > 1.0f) {
sahilmgandhi 18:6a4db94011d3 120 value = 1.0f;
sahilmgandhi 18:6a4db94011d3 121 }
sahilmgandhi 18:6a4db94011d3 122 uint32_t t_on = (uint32_t)((float)(obj->pwm->MATCHREL[obj->pwm_ch * 2] + 1) * value);
sahilmgandhi 18:6a4db94011d3 123 if (t_on > 0) { // duty is not 0%
sahilmgandhi 18:6a4db94011d3 124 if (value != 1.0f) { // duty is not 100%
sahilmgandhi 18:6a4db94011d3 125 obj->pwm->MATCHREL[(obj->pwm_ch * 2) + 1] = t_on - 1;
sahilmgandhi 18:6a4db94011d3 126 // unhalt the counter
sahilmgandhi 18:6a4db94011d3 127 obj->pwm->CTRL &= ~(1 << 2);
sahilmgandhi 18:6a4db94011d3 128 } else { // duty is 100%
sahilmgandhi 18:6a4db94011d3 129 // halt and clear the counter
sahilmgandhi 18:6a4db94011d3 130 obj->pwm->CTRL |= (1 << 2) | (1 << 3);
sahilmgandhi 18:6a4db94011d3 131 // output level tied to high
sahilmgandhi 18:6a4db94011d3 132 obj->pwm->OUTPUT |= (1 << obj->pwm_ch);
sahilmgandhi 18:6a4db94011d3 133 }
sahilmgandhi 18:6a4db94011d3 134 } else { // duty is 0%
sahilmgandhi 18:6a4db94011d3 135 // halt and clear the counter
sahilmgandhi 18:6a4db94011d3 136 obj->pwm->CTRL |= (1 << 2) | (1 << 3);
sahilmgandhi 18:6a4db94011d3 137 // output level tied to low
sahilmgandhi 18:6a4db94011d3 138 obj->pwm->OUTPUT &= ~(1 << obj->pwm_ch);
sahilmgandhi 18:6a4db94011d3 139 }
sahilmgandhi 18:6a4db94011d3 140 }
sahilmgandhi 18:6a4db94011d3 141
sahilmgandhi 18:6a4db94011d3 142 float pwmout_read(pwmout_t* obj)
sahilmgandhi 18:6a4db94011d3 143 {
sahilmgandhi 18:6a4db94011d3 144 uint32_t t_off = obj->pwm->MATCHREL[(obj->pwm_ch * 2) + 0] + 1;
sahilmgandhi 18:6a4db94011d3 145 uint32_t t_on = obj->pwm->MATCHREL[(obj->pwm_ch * 2) + 1] + 1;
sahilmgandhi 18:6a4db94011d3 146 float v = (float)t_on/(float)t_off;
sahilmgandhi 18:6a4db94011d3 147 return (v > 1.0f) ? (1.0f) : (v);
sahilmgandhi 18:6a4db94011d3 148 }
sahilmgandhi 18:6a4db94011d3 149
sahilmgandhi 18:6a4db94011d3 150 void pwmout_period(pwmout_t* obj, float seconds)
sahilmgandhi 18:6a4db94011d3 151 {
sahilmgandhi 18:6a4db94011d3 152 pwmout_period_us(obj, seconds * 1000000.0f);
sahilmgandhi 18:6a4db94011d3 153 }
sahilmgandhi 18:6a4db94011d3 154
sahilmgandhi 18:6a4db94011d3 155 void pwmout_period_ms(pwmout_t* obj, int ms)
sahilmgandhi 18:6a4db94011d3 156 {
sahilmgandhi 18:6a4db94011d3 157 pwmout_period_us(obj, ms * 1000);
sahilmgandhi 18:6a4db94011d3 158 }
sahilmgandhi 18:6a4db94011d3 159
sahilmgandhi 18:6a4db94011d3 160 // Set the PWM period, keeping the duty cycle the same.
sahilmgandhi 18:6a4db94011d3 161 void pwmout_period_us(pwmout_t* obj, int us)
sahilmgandhi 18:6a4db94011d3 162 {
sahilmgandhi 18:6a4db94011d3 163 // The period are off by one for MATCHREL, so +1 to get actual value
sahilmgandhi 18:6a4db94011d3 164 uint32_t t_off = obj->pwm->MATCHREL[(obj->pwm_ch * 2) + 0] + 1;
sahilmgandhi 18:6a4db94011d3 165 uint32_t t_on = obj->pwm->MATCHREL[(obj->pwm_ch * 2) + 1] + 1;
sahilmgandhi 18:6a4db94011d3 166 float v = (float)t_on/(float)t_off;
sahilmgandhi 18:6a4db94011d3 167 obj->pwm->MATCHREL[(obj->pwm_ch * 2) + 0] = (uint32_t)us - 1;
sahilmgandhi 18:6a4db94011d3 168 if (us > 0) { // PWM period is not 0
sahilmgandhi 18:6a4db94011d3 169 obj->pwm->MATCHREL[(obj->pwm_ch * 2) + 1] = (uint32_t)((float)us * (float)v) - 1;
sahilmgandhi 18:6a4db94011d3 170 // unhalt the counter
sahilmgandhi 18:6a4db94011d3 171 obj->pwm->CTRL &= ~(1 << 2);
sahilmgandhi 18:6a4db94011d3 172 } else { // PWM period is 0
sahilmgandhi 18:6a4db94011d3 173 // halt and clear the counter
sahilmgandhi 18:6a4db94011d3 174 obj->pwm->CTRL |= (1 << 2) | (1 << 3);
sahilmgandhi 18:6a4db94011d3 175 // output level tied to low
sahilmgandhi 18:6a4db94011d3 176 obj->pwm->OUTPUT &= ~(1 << obj->pwm_ch);
sahilmgandhi 18:6a4db94011d3 177 }
sahilmgandhi 18:6a4db94011d3 178 }
sahilmgandhi 18:6a4db94011d3 179
sahilmgandhi 18:6a4db94011d3 180 void pwmout_pulsewidth(pwmout_t* obj, float seconds)
sahilmgandhi 18:6a4db94011d3 181 {
sahilmgandhi 18:6a4db94011d3 182 pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
sahilmgandhi 18:6a4db94011d3 183 }
sahilmgandhi 18:6a4db94011d3 184
sahilmgandhi 18:6a4db94011d3 185 void pwmout_pulsewidth_ms(pwmout_t* obj, int ms)
sahilmgandhi 18:6a4db94011d3 186 {
sahilmgandhi 18:6a4db94011d3 187 pwmout_pulsewidth_us(obj, ms * 1000);
sahilmgandhi 18:6a4db94011d3 188 }
sahilmgandhi 18:6a4db94011d3 189
sahilmgandhi 18:6a4db94011d3 190 void pwmout_pulsewidth_us(pwmout_t* obj, int us)
sahilmgandhi 18:6a4db94011d3 191 {
sahilmgandhi 18:6a4db94011d3 192 if (us > 0) { // PWM peried is not 0
sahilmgandhi 18:6a4db94011d3 193 obj->pwm->MATCHREL[(obj->pwm_ch * 2) + 1] = (uint32_t)us - 1;
sahilmgandhi 18:6a4db94011d3 194 obj->pwm->CTRL &= ~(1 << 2);
sahilmgandhi 18:6a4db94011d3 195 } else { //PWM period is 0
sahilmgandhi 18:6a4db94011d3 196 // halt and clear the counter
sahilmgandhi 18:6a4db94011d3 197 obj->pwm->CTRL |= (1 << 2) | (1 << 3);
sahilmgandhi 18:6a4db94011d3 198 // output level tied to low
sahilmgandhi 18:6a4db94011d3 199 obj->pwm->OUTPUT &= ~(1 << obj->pwm_ch);
sahilmgandhi 18:6a4db94011d3 200 }
sahilmgandhi 18:6a4db94011d3 201 }
sahilmgandhi 18:6a4db94011d3 202
sahilmgandhi 18:6a4db94011d3 203 #endif