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/*******************************************************************************
* Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the name of Maxim Integrated
* Products, Inc. shall not be used except as stated in the Maxim Integrated
* Products, Inc. Branding Policy.
*
* The mere transfer of this software does not imply any licenses
* of trade secrets, proprietary technology, copyrights, patents,
* trademarks, maskwork rights, or any other form of intellectual
* property whatsoever. Maxim Integrated Products, Inc. retains all
* ownership rights.
*******************************************************************************
*/
#include "mbed_assert.h"
#include "cmsis.h"
#include "pwmout_api.h"
#include "pinmap.h"
#include "ioman_regs.h"
#include "clkman_regs.h"
#include "PeripheralPins.h"
//******************************************************************************
void pwmout_init(pwmout_t* obj, PinName pin)
{
// Make sure the pin is free for GPIO use
unsigned int port = (unsigned int)pin >> PORT_SHIFT;
unsigned int port_pin = (unsigned int)pin & ~(0xFFFFFFFF << PORT_SHIFT);
MBED_ASSERT(MXC_GPIO->free[port] & (0x1 << port_pin));
int i = 0;
PinMap pwm = PinMap_PWM[0];
// Check if there is a pulse train already active on this port
int pin_func = (MXC_GPIO->func_sel[port] & (0xF << (port_pin*4))) >> (port_pin*4);
if((pin_func > 0) && (pin_func < 4)) {
// Search through PinMap_PWM to find the active PT
while(pwm.pin != (PinName)NC) {
if((pwm.pin == pin) && (pwm.function == pin_func)) {
break;
}
pwm = PinMap_PWM[++i];
}
} else {
// Search through PinMap_PWM to find an available PT
int i = 0;
while(pwm.pin != (PinName)NC && (i > -1)) {
pwm = PinMap_PWM[i++];
if(pwm.pin == pin) {
// Check each instance of PT
while(1) {
// Check to see if this PT instance is already in use
if((((mxc_pt_regs_t*)pwm.peripheral)->rate_length &
MXC_F_PT_RATE_LENGTH_MODE)) {
i = -1;
break;
}
// If all instances are in use, overwrite the last
pwm = PinMap_PWM[++i];
if(pwm.pin != pin) {
pwm = PinMap_PWM[--i];
i = -1;
break;
}
}
}
}
}
// Make sure we found an available PWM generator
MBED_ASSERT(pwm.pin != (PinName)NC);
// Disable all pwm output
MXC_PTG->ctrl = 0;
// Enable the clock
MXC_CLKMAN->clk_ctrl_2_pt = MXC_E_CLKMAN_CLK_SCALE_ENABLED;
// Set the drive mode to normal
MXC_SET_FIELD(&MXC_GPIO->out_mode[port], (0x7 << (port_pin*4)), (MXC_V_GPIO_OUT_MODE_NORMAL_DRIVE << (port_pin*4)));
// Set the obj pointer to the propper PWM instance
obj->pwm = (mxc_pt_regs_t*)pwm.peripheral;
// Initialize object period and pulse width
obj->period = -1;
obj->pulse_width = -1;
// Disable the output
obj->pwm->train = 0x0;
obj->pwm->rate_length = 0x0;
// Configure the pin
pin_mode(pin, (PinMode)PullNone);
pin_function(pin, pwm.function);
// default to 20ms: standard for servos, and fine for e.g. brightness control
pwmout_period_us(obj, 20000);
pwmout_write (obj, 0);
// Enable the global pwm
MXC_PTG->ctrl = MXC_F_PT_CTRL_ENABLE_ALL;
}
//******************************************************************************
void pwmout_free(pwmout_t* obj)
{
// Set the registers to the reset value
obj->pwm->train = 0;
obj->pwm->rate_length = 0x08000000;
}
//******************************************************************************
static void pwmout_update(pwmout_t* obj)
{
// Calculate and set the divider ratio
int div = (obj->period * (SystemCoreClock/1000000))/32;
if (div < 2){
div = 2;
}
MXC_SET_FIELD(&obj->pwm->rate_length, MXC_F_PT_RATE_LENGTH_RATE_CONTROL, div);
// Change the duty cycle to adjust the pulse width
obj->pwm->train = (0xFFFFFFFF << (32-((32*obj->pulse_width)/obj->period)));
}
//******************************************************************************
void pwmout_write(pwmout_t* obj, float percent)
{
// Saturate percent if outside of range
if(percent < 0.0) {
percent = 0.0;
} else if(percent > 1.0) {
percent = 1.0;
}
// Resize the pulse width to set the duty cycle
pwmout_pulsewidth_us(obj, (int)(percent*obj->period));
}
//******************************************************************************
float pwmout_read(pwmout_t* obj)
{
// Check for when pulsewidth or period equals 0
if((obj->pulse_width == 0) || (obj->period == 0)){
return 0;
}
// Return the duty cycle
return ((float)obj->pulse_width / (float)obj->period);
}
//******************************************************************************
void pwmout_period(pwmout_t* obj, float seconds)
{
pwmout_period_us(obj, (int)(seconds * 1000000.0));
}
//******************************************************************************
void pwmout_period_ms(pwmout_t* obj, int ms)
{
pwmout_period_us(obj, ms*1000);
}
//******************************************************************************
void pwmout_period_us(pwmout_t* obj, int us)
{
// Check the range of the period
MBED_ASSERT((us >= 0) && (us <= (int)(SystemCoreClock/32)));
// Set pulse width to half the period if uninitialized
if(obj->pulse_width == -1){
obj->pulse_width = us/2;
}
// Save the period
obj->period = us;
// Update the registers
pwmout_update(obj);
}
//******************************************************************************
void pwmout_pulsewidth(pwmout_t* obj, float seconds)
{
pwmout_pulsewidth_us(obj, (int)(seconds * 1000000.0));
}
//******************************************************************************
void pwmout_pulsewidth_ms(pwmout_t* obj, int ms)
{
pwmout_pulsewidth_us(obj, ms*1000);
}
//******************************************************************************
void pwmout_pulsewidth_us(pwmout_t* obj, int us)
{
// Check the range of the pulsewidth
MBED_ASSERT((us >= 0) && (us <= (int)(SystemCoreClock/32)));
// Initialize period to double the pulsewidth if uninitialized
if(obj->period == -1){
obj->period = 2*us;
}
// Save the pulsewidth
obj->pulse_width = us;
// Update the register
pwmout_update(obj);
}
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