GameOpener / mbed-src

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Fork of mbed-src by mbed official

targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/pwmout_api.c@556:a217bc785985, 2015-06-03 (annotated)

Committer:
mbed_official
Date:
Wed Jun 03 08:30:08 2015 +0100
Revision:
556:a217bc785985
Parent:
554:edd95c0879f8 
Synchronized with git revision dd1ab3a5e660410cfbfd2286c513ef820ed2d22f



Full URL: https://github.com/mbedmicro/mbed/commit/dd1ab3a5e660410cfbfd2286c513ef820ed2d22f/



Silicon Labs - Improvements in RAM footprint of HAL.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 525:c320967f86b9 1 /* mbed Microcontroller Library
mbed_official 525:c320967f86b9 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 525:c320967f86b9 3 *
mbed_official 525:c320967f86b9 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 525:c320967f86b9 5 * you may not use this file except in compliance with the License.
mbed_official 525:c320967f86b9 6 * You may obtain a copy of the License at
mbed_official 525:c320967f86b9 7 *
mbed_official 525:c320967f86b9 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 525:c320967f86b9 9 *
mbed_official 525:c320967f86b9 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 525:c320967f86b9 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 525:c320967f86b9 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 525:c320967f86b9 13 * See the License for the specific language governing permissions and
mbed_official 525:c320967f86b9 14 * limitations under the License.
mbed_official 525:c320967f86b9 15 */
mbed_official 525:c320967f86b9 16
mbed_official 525:c320967f86b9 17 #include "device.h"
mbed_official 525:c320967f86b9 18 #include "clocking.h"
mbed_official 525:c320967f86b9 19 #if DEVICE_PWMOUT
mbed_official 525:c320967f86b9 20
mbed_official 525:c320967f86b9 21 #include "mbed_assert.h"
mbed_official 525:c320967f86b9 22 #include "pwmout_api.h"
mbed_official 525:c320967f86b9 23 #include "cmsis.h"
mbed_official 525:c320967f86b9 24 #include "pinmap.h"
mbed_official 525:c320967f86b9 25 #include "PeripheralPins.h"
mbed_official 525:c320967f86b9 26 #include "device_peripherals.h"
mbed_official 544:1af5f1c39e80 27 #include "sleepmodes.h"
mbed_official 525:c320967f86b9 28
mbed_official 525:c320967f86b9 29 #include "em_cmu.h"
mbed_official 525:c320967f86b9 30 #include "em_gpio.h"
mbed_official 525:c320967f86b9 31 #include "em_timer.h"
mbed_official 525:c320967f86b9 32
mbed_official 544:1af5f1c39e80 33 static int pwm_prescaler_div;
mbed_official 525:c320967f86b9 34
mbed_official 548:1abac31e188e 35 uint32_t pwmout_get_channel_route(pwmout_t *obj)
mbed_official 548:1abac31e188e 36 {
mbed_official 548:1abac31e188e 37 MBED_ASSERT(obj->channel != (PWMName) NC);
mbed_official 525:c320967f86b9 38
mbed_official 548:1abac31e188e 39 switch (obj->channel) {
mbed_official 548:1abac31e188e 40 case PWM_CH0:
mbed_official 548:1abac31e188e 41 return TIMER_ROUTE_CC0PEN;
mbed_official 548:1abac31e188e 42 break;
mbed_official 548:1abac31e188e 43 case PWM_CH1:
mbed_official 548:1abac31e188e 44 return TIMER_ROUTE_CC1PEN;
mbed_official 548:1abac31e188e 45 break;
mbed_official 548:1abac31e188e 46 case PWM_CH2:
mbed_official 548:1abac31e188e 47 return TIMER_ROUTE_CC2PEN;
mbed_official 548:1abac31e188e 48 break;
mbed_official 548:1abac31e188e 49 default:
mbed_official 548:1abac31e188e 50 return 0;
mbed_official 548:1abac31e188e 51 }
mbed_official 525:c320967f86b9 52 }
mbed_official 525:c320967f86b9 53
mbed_official 525:c320967f86b9 54 void pwmout_enable_pins(pwmout_t *obj, uint8_t enable)
mbed_official 525:c320967f86b9 55 {
mbed_official 525:c320967f86b9 56 if (enable) {
mbed_official 525:c320967f86b9 57 pin_mode(obj->pin, PushPull);
mbed_official 525:c320967f86b9 58 } else {
mbed_official 525:c320967f86b9 59 // TODO_LP return PinMode to the previous state
mbed_official 525:c320967f86b9 60 pin_mode(obj->pin, Disabled);
mbed_official 525:c320967f86b9 61 }
mbed_official 525:c320967f86b9 62 }
mbed_official 525:c320967f86b9 63
mbed_official 525:c320967f86b9 64 void pwmout_enable(pwmout_t *obj, uint8_t enable)
mbed_official 525:c320967f86b9 65 {
mbed_official 548:1abac31e188e 66 /* Start with default CC (Compare/Capture) channel parameters */
mbed_official 548:1abac31e188e 67 TIMER_InitCC_TypeDef timerCCInit = TIMER_INITCC_DEFAULT;
mbed_official 525:c320967f86b9 68 if (enable) {
mbed_official 525:c320967f86b9 69 /* Set mode to PWM */
mbed_official 525:c320967f86b9 70 timerCCInit.mode = timerCCModePWM;
mbed_official 544:1af5f1c39e80 71 }
mbed_official 525:c320967f86b9 72
mbed_official 544:1af5f1c39e80 73 /* Configure CC channel */
mbed_official 544:1af5f1c39e80 74 TIMER_InitCC(PWM_TIMER, obj->channel, &timerCCInit);
mbed_official 525:c320967f86b9 75 }
mbed_official 525:c320967f86b9 76
mbed_official 544:1af5f1c39e80 77 void pwmout_init(pwmout_t *obj, PinName pin)
mbed_official 544:1af5f1c39e80 78 {
mbed_official 548:1abac31e188e 79 obj->channel = (PWMName) pinmap_peripheral(pin, PinMap_PWM);
mbed_official 548:1abac31e188e 80 obj->pin = pin;
mbed_official 548:1abac31e188e 81 MBED_ASSERT(obj->channel != (PWMName) NC);
mbed_official 544:1af5f1c39e80 82
mbed_official 548:1abac31e188e 83 /* Turn on clock */
mbed_official 548:1abac31e188e 84 CMU_ClockEnable(PWM_TIMER_CLOCK, true);
mbed_official 544:1af5f1c39e80 85
mbed_official 548:1abac31e188e 86 /* Turn on timer */
mbed_official 548:1abac31e188e 87 if(!(PWM_TIMER->STATUS & TIMER_STATUS_RUNNING)) {
mbed_official 548:1abac31e188e 88 TIMER_Init_TypeDef timerInit = TIMER_INIT_DEFAULT;
mbed_official 548:1abac31e188e 89 TIMER_Init(PWM_TIMER, &timerInit);
mbed_official 548:1abac31e188e 90 }
mbed_official 544:1af5f1c39e80 91
mbed_official 544:1af5f1c39e80 92 /* Enable correct channel */
mbed_official 548:1abac31e188e 93 uint32_t routeloc = pwmout_get_channel_route(obj);
mbed_official 548:1abac31e188e 94 if(PWM_TIMER->ROUTE & routeloc) {
mbed_official 548:1abac31e188e 95 //This channel was already in use
mbed_official 548:1abac31e188e 96 //TODO: gracefully handle this case
mbed_official 548:1abac31e188e 97 } else {
mbed_official 548:1abac31e188e 98 //This channel was unused up to now
mbed_official 548:1abac31e188e 99 PWM_TIMER->ROUTE |= routeloc;
mbed_official 548:1abac31e188e 100 blockSleepMode(EM1);
mbed_official 544:1af5f1c39e80 101
mbed_official 548:1abac31e188e 102 //TODO: check if any channel was up already, then don't re-init timer
mbed_official 548:1abac31e188e 103 pwmout_enable(obj, true);
mbed_official 548:1abac31e188e 104 pwmout_enable_pins(obj, true);
mbed_official 548:1abac31e188e 105 }
mbed_official 544:1af5f1c39e80 106
mbed_official 544:1af5f1c39e80 107 /* Route correct channel to location 1 */
mbed_official 544:1af5f1c39e80 108 PWM_TIMER->ROUTE &= ~_TIMER_ROUTE_LOCATION_MASK;
mbed_official 544:1af5f1c39e80 109 PWM_TIMER->ROUTE |= PWM_ROUTE;
mbed_official 544:1af5f1c39e80 110
mbed_official 544:1af5f1c39e80 111 /* Set default 20ms frequency and 0ms pulse width */
mbed_official 544:1af5f1c39e80 112 pwmout_period(obj, 0.02);
mbed_official 544:1af5f1c39e80 113 }
mbed_official 544:1af5f1c39e80 114
mbed_official 548:1abac31e188e 115 void pwmout_free(pwmout_t *obj)
mbed_official 548:1abac31e188e 116 {
mbed_official 548:1abac31e188e 117 uint32_t routeloc = pwmout_get_channel_route(obj);
mbed_official 548:1abac31e188e 118 if(PWM_TIMER->ROUTE & routeloc) {
mbed_official 548:1abac31e188e 119 //This channel was in use, so disable
mbed_official 548:1abac31e188e 120 PWM_TIMER->ROUTE &= ~routeloc;
mbed_official 548:1abac31e188e 121 pwmout_enable_pins(obj, false);
mbed_official 548:1abac31e188e 122 unblockSleepMode(EM1);
mbed_official 544:1af5f1c39e80 123
mbed_official 548:1abac31e188e 124 //TODO: check if all channels are down, then switch off timer
mbed_official 548:1abac31e188e 125 } else {
mbed_official 548:1abac31e188e 126 //This channel was disabled already
mbed_official 548:1abac31e188e 127 }
mbed_official 544:1af5f1c39e80 128 }
mbed_official 525:c320967f86b9 129
mbed_official 525:c320967f86b9 130 void pwmout_write(pwmout_t *obj, float value)
mbed_official 525:c320967f86b9 131 {
mbed_official 525:c320967f86b9 132 if (value < 0.0f) {
mbed_official 525:c320967f86b9 133 value = 0;
mbed_official 525:c320967f86b9 134 } else if (value > 1.0f) {
mbed_official 525:c320967f86b9 135 value = 1;
mbed_official 525:c320967f86b9 136 }
mbed_official 525:c320967f86b9 137
mbed_official 556:a217bc785985 138 float pulse_period_in_s = obj->period_cycles / ((float) (REFERENCE_FREQUENCY >> pwm_prescaler_div));
mbed_official 525:c320967f86b9 139 pwmout_pulsewidth(obj, value * pulse_period_in_s);
mbed_official 525:c320967f86b9 140 }
mbed_official 525:c320967f86b9 141
mbed_official 525:c320967f86b9 142 float pwmout_read(pwmout_t *obj)
mbed_official 525:c320967f86b9 143 {
mbed_official 525:c320967f86b9 144 return obj->width_cycles / (float) obj->period_cycles;
mbed_official 525:c320967f86b9 145 }
mbed_official 525:c320967f86b9 146
mbed_official 525:c320967f86b9 147 // Set the PWM period, keeping the absolute pulse width the same.
mbed_official 525:c320967f86b9 148 void pwmout_period(pwmout_t *obj, float seconds)
mbed_official 525:c320967f86b9 149 {
mbed_official 525:c320967f86b9 150 // Find the lowest prescaler divider possible.
mbed_official 525:c320967f86b9 151 // This gives us max resolution for a given period
mbed_official 525:c320967f86b9 152
mbed_official 525:c320967f86b9 153 //The value of the top register if prescaler is set to 0
mbed_official 556:a217bc785985 154 int cycles = REFERENCE_FREQUENCY * seconds;
mbed_official 544:1af5f1c39e80 155 pwm_prescaler_div = 0;
mbed_official 525:c320967f86b9 156
mbed_official 525:c320967f86b9 157 //The top register is only 16 bits, so we keep dividing till we are below 0xFFFF
mbed_official 525:c320967f86b9 158 while (cycles > 0xFFFF) {
mbed_official 525:c320967f86b9 159 cycles /= 2;
mbed_official 544:1af5f1c39e80 160 pwm_prescaler_div++;
mbed_official 525:c320967f86b9 161
mbed_official 544:1af5f1c39e80 162 //Max pwm_prescaler_div supported is 10
mbed_official 544:1af5f1c39e80 163 if (pwm_prescaler_div > 10) {
mbed_official 544:1af5f1c39e80 164 pwm_prescaler_div = 10;
mbed_official 525:c320967f86b9 165 cycles = 0xFFFF; //Set it to max possible value;
mbed_official 525:c320967f86b9 166 break;
mbed_official 525:c320967f86b9 167 }
mbed_official 525:c320967f86b9 168 }
mbed_official 525:c320967f86b9 169
mbed_official 525:c320967f86b9 170 obj->period_cycles = cycles;
mbed_official 525:c320967f86b9 171
mbed_official 525:c320967f86b9 172 //Set prescaler
mbed_official 544:1af5f1c39e80 173 PWM_TIMER->CTRL = (PWM_TIMER->CTRL & ~_TIMER_CTRL_PRESC_MASK) | (pwm_prescaler_div << _TIMER_CTRL_PRESC_SHIFT);
mbed_official 525:c320967f86b9 174
mbed_official 525:c320967f86b9 175 /* Set Top Value, which controls the PWM period */
mbed_official 525:c320967f86b9 176 TIMER_TopSet(PWM_TIMER, obj->period_cycles);
mbed_official 525:c320967f86b9 177 }
mbed_official 525:c320967f86b9 178
mbed_official 525:c320967f86b9 179 void pwmout_period_ms(pwmout_t *obj, int ms)
mbed_official 525:c320967f86b9 180 {
mbed_official 525:c320967f86b9 181 pwmout_period(obj, ms / 1000.0f);
mbed_official 525:c320967f86b9 182 }
mbed_official 525:c320967f86b9 183
mbed_official 525:c320967f86b9 184 void pwmout_period_us(pwmout_t *obj, int us)
mbed_official 525:c320967f86b9 185 {
mbed_official 556:a217bc785985 186 pwmout_period(obj, us / 1000000.0f);
mbed_official 525:c320967f86b9 187 }
mbed_official 525:c320967f86b9 188
mbed_official 525:c320967f86b9 189 void pwmout_pulsewidth(pwmout_t *obj, float seconds)
mbed_official 525:c320967f86b9 190 {
mbed_official 556:a217bc785985 191 obj->width_cycles = (uint32_t) (((float) (REFERENCE_FREQUENCY >> pwm_prescaler_div)) * seconds);
mbed_official 525:c320967f86b9 192 TIMER_CompareBufSet(PWM_TIMER, obj->channel, obj->width_cycles);
mbed_official 525:c320967f86b9 193 }
mbed_official 525:c320967f86b9 194
mbed_official 525:c320967f86b9 195 void pwmout_pulsewidth_ms(pwmout_t *obj, int ms)
mbed_official 525:c320967f86b9 196 {
mbed_official 556:a217bc785985 197 obj->width_cycles = (uint32_t) ((REFERENCE_FREQUENCY >> pwm_prescaler_div) * ms) / 1000;
mbed_official 556:a217bc785985 198 TIMER_CompareBufSet(PWM_TIMER, obj->channel, obj->width_cycles);
mbed_official 525:c320967f86b9 199 }
mbed_official 525:c320967f86b9 200
mbed_official 525:c320967f86b9 201 void pwmout_pulsewidth_us(pwmout_t *obj, int us)
mbed_official 525:c320967f86b9 202 {
mbed_official 556:a217bc785985 203 obj->width_cycles = (uint32_t) ((REFERENCE_FREQUENCY >> pwm_prescaler_div) * us) / 1000000;
mbed_official 556:a217bc785985 204 TIMER_CompareBufSet(PWM_TIMER, obj->channel, obj->width_cycles);
mbed_official 525:c320967f86b9 205 }
mbed_official 525:c320967f86b9 206
mbed_official 525:c320967f86b9 207 #endif