diff options
Diffstat (limited to 'tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC81X/pwmout_api.c')
| -rw-r--r-- | tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC81X/pwmout_api.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC81X/pwmout_api.c b/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC81X/pwmout_api.c new file mode 100644 index 0000000000..393d51981a --- /dev/null +++ b/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC81X/pwmout_api.c @@ -0,0 +1,227 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2013 ARM Limited + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#include "mbed_assert.h" +#include "pwmout_api.h" +#include "cmsis.h" +#include "pinmap.h" +#include "mbed_error.h" + +// Ported from LPC824 and adapted. + +#if DEVICE_PWMOUT + +#define PWM_IRQn SCT_IRQn + +// Bit flags for used SCT Outputs +static unsigned char sct_used = 0; +static int sct_inited = 0; + +// Find available output channel +// Max number of PWM outputs is 4 on LPC812 +static int get_available_sct() { + int i; + +// Find available output channel 0..3 +// Also need one Match register per channel + for (i = 0; i < CONFIG_SCT_nOU; i++) { +// for (i = 0; i < 4; i++) { + if ((sct_used & (1 << i)) == 0) + return i; + } + return -1; +} + +// Any Port pin may be used for PWM. +// Max number of PWM outputs is 4 +void pwmout_init(pwmout_t* obj, PinName pin) { + MBED_ASSERT(pin != (uint32_t)NC); + + int sct_n = get_available_sct(); + if (sct_n == -1) { + error("No available SCT Output"); + } + + sct_used |= (1 << sct_n); + + obj->pwm = (LPC_SCT_TypeDef*)LPC_SCT; + obj->pwm_ch = sct_n; + + LPC_SCT_TypeDef* pwm = obj->pwm; + + // Init SCT on first use + if (! sct_inited) { + sct_inited = 1; + + // Enable the SCT clock + LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 8); + + // Clear peripheral reset the SCT: + LPC_SYSCON->PRESETCTRL |= (1 << 8); + + // Two 16-bit counters, autolimit (ie reset on Match_0) + //pwm->CONFIG &= ~(0x1); + //pwm->CONFIG |= (1 << 17); + pwm->CONFIG |= ((0x3 << 17) | 0x01); + + // halt and clear the counter + pwm->CTRL_U |= (1 << 2) | (1 << 3); + + // System Clock (30 Mhz) -> Prescaler -> us_ticker (1 MHz) + pwm->CTRL_U &= ~(0x7F << 5); + pwm->CTRL_U |= (((SystemCoreClock/1000000 - 1) & 0x7F) << 5); + + pwm->EVENT[0].CTRL = (1 << 12) | 0; // Event_0 on Match_0 + pwm->EVENT[0].STATE = 0xFFFFFFFF; // All states + + // unhalt the counter: + // - clearing bit 2 of the CTRL register + pwm->CTRL_U &= ~(1 << 2); + + // Not using IRQs + //NVIC_SetVector(PWM_IRQn, (uint32_t)pwm_irq_handler); + //NVIC_EnableIRQ(PWM_IRQn); + } + + // LPC81x has only one SCT and 4 Outputs + // LPC82x has only one SCT and 6 Outputs + // LPC1549 has 4 SCTs and 16 Outputs + switch(sct_n) { + case 0: + // SCTx_OUT0 + LPC_SWM->PINASSIGN[6] &= ~0xFF000000; + LPC_SWM->PINASSIGN[6] |= (pin << 24); + break; + case 1: + // SCTx_OUT1 + LPC_SWM->PINASSIGN[7] &= ~0x000000FF; + LPC_SWM->PINASSIGN[7] |= (pin); + break; + case 2: + // SCTx_OUT2 + LPC_SWM->PINASSIGN[7] &= ~0x0000FF00; + LPC_SWM->PINASSIGN[7] |= (pin << 8); + break; + case 3: + // SCTx_OUT3 + LPC_SWM->PINASSIGN[7] &= ~0x00FF0000; + LPC_SWM->PINASSIGN[7] |= (pin << 16); + break; + default: + break; + } + + pwm->EVENT[sct_n + 1].CTRL = (1 << 12) | (sct_n + 1); // Event_n on Match_n + pwm->EVENT[sct_n + 1].STATE = 0xFFFFFFFF; // All states + + pwm->OUT[sct_n].SET = (1 << 0); // All PWM channels are SET on Event_0 + pwm->OUT[sct_n].CLR = (1 << (sct_n + 1)); // PWM ch is CLRed on Event_(ch+1) + + // default to 20ms: standard for servos, and fine for e.g. brightness control + pwmout_period_ms(obj, 20); // 20ms period + pwmout_write (obj, 0.0); // 0ms pulsewidth, dutycycle 0 +} + +void pwmout_free(pwmout_t* obj) { + // PWM channel is now free + sct_used &= ~(1 << obj->pwm_ch); + + // Disable the SCT clock when all channels free + if (sct_used == 0) { + LPC_SYSCON->SYSAHBCLKCTRL &= ~(1 << 8); + sct_inited = 0; + }; +} + +// Set new dutycycle (0.0 .. 1.0) +void pwmout_write(pwmout_t* obj, float value) { + //value is new dutycycle + if (value < 0.0f) { + value = 0.0; + } else if (value > 1.0f) { + value = 1.0; + } + + // Match_0 is PWM period. Compute new endtime of pulse for current channel + uint32_t t_off = (uint32_t)((float)(obj->pwm->MATCHREL[0].U) * value); + obj->pwm->MATCHREL[(obj->pwm_ch) + 1].U = t_off; // New endtime +} + +// Get dutycycle (0.0 .. 1.0) +float pwmout_read(pwmout_t* obj) { + uint32_t t_period = obj->pwm->MATCHREL[0].U; + + //Sanity check + if (t_period == 0) { + return 0.0; + }; + + uint32_t t_off = obj->pwm->MATCHREL[(obj->pwm_ch) + 1].U; + float v = (float)t_off/(float)t_period; + //Sanity check + return (v > 1.0f) ? (1.0f) : (v); +} + +// Set the PWM period, keeping the duty cycle the same (for this channel only!). +void pwmout_period(pwmout_t* obj, float seconds){ + pwmout_period_us(obj, seconds * 1000000.0f); +} + +// Set the PWM period, keeping the duty cycle the same (for this channel only!). +void pwmout_period_ms(pwmout_t* obj, int ms) { + pwmout_period_us(obj, ms * 1000); +} + +// Set the PWM period, keeping the duty cycle the same (for this channel only!). +void pwmout_period_us(pwmout_t* obj, int us) { + + uint32_t t_period = obj->pwm->MATCHREL[0].U; // Current PWM period + obj->pwm->MATCHREL[0].U = (uint32_t)us; // New PWM period + + //Keep the dutycycle for the new PWM period + //Should really do this for all active channels!! + //This problem exists in all mbed libs. + + //Sanity check + if (t_period == 0) { + return; +// obj->pwm->MATCHREL[(obj->pwm_ch) + 1].L = 0; // New endtime for this channel + } + else { + uint32_t t_off = obj->pwm->MATCHREL[(obj->pwm_ch) + 1].U; + float v = (float)t_off/(float)t_period; + obj->pwm->MATCHREL[(obj->pwm_ch) + 1].U = (uint32_t)((float)us * (float)v); // New endtime for this channel + } +} + + +//Set pulsewidth +void pwmout_pulsewidth(pwmout_t* obj, float seconds) { + pwmout_pulsewidth_us(obj, seconds * 1000000.0f); +} + +//Set pulsewidth +void pwmout_pulsewidth_ms(pwmout_t* obj, int ms){ + pwmout_pulsewidth_us(obj, ms * 1000); +} + +//Set pulsewidth +void pwmout_pulsewidth_us(pwmout_t* obj, int us) { + +//Should add Sanity check to make sure pulsewidth < period! + obj->pwm->MATCHREL[(obj->pwm_ch) + 1].U = (uint32_t)us; // New endtime for this channel +} + +#endif |