mirror of https://github.com/ARMmbed/mbed-os.git
214 lines
6.9 KiB
C
214 lines
6.9 KiB
C
/*******************************************************************************
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* Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
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* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*
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* Except as contained in this notice, the name of Maxim Integrated
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* Products, Inc. shall not be used except as stated in the Maxim Integrated
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* Products, Inc. Branding Policy.
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*
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* The mere transfer of this software does not imply any licenses
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* of trade secrets, proprietary technology, copyrights, patents,
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* trademarks, maskwork rights, or any other form of intellectual
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* property whatsoever. Maxim Integrated Products, Inc. retains all
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* ownership rights.
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*******************************************************************************
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*/
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#include "mbed_assert.h"
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#include "cmsis.h"
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#include "pwmout_api.h"
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#include "pinmap.h"
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#include "ioman_regs.h"
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#include "clkman_regs.h"
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#include "PeripheralPins.h"
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//******************************************************************************
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void pwmout_init(pwmout_t* obj, PinName pin)
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{
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// Make sure the pin is free for GPIO use
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unsigned int port = (unsigned int)pin >> PORT_SHIFT;
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unsigned int port_pin = (unsigned int)pin & ~(0xFFFFFFFF << PORT_SHIFT);
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MBED_ASSERT(MXC_GPIO->free[port] & (0x1 << port_pin));
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int i = 0;
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PinMap pwm = PinMap_PWM[0];
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// Check if there is a pulse train already active on this port
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int pin_func = (MXC_GPIO->func_sel[port] & (0xF << (port_pin*4))) >> (port_pin*4);
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MBED_ASSERT((pin_func < 1) || (pin_func > 3));
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// Search through PinMap_PWM to find the pin
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while(pwm.pin != pin) {
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pwm = PinMap_PWM[++i];
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}
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// Find a free PT instance on this pin
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while(pwm.pin == pin) {
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// Check to see if this PT instance is free
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if((((mxc_pt_regs_t*)pwm.peripheral)->rate_length &
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MXC_F_PT_RATE_LENGTH_MODE)) {
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break;
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}
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pwm = PinMap_PWM[++i];
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// Raise an assertion if we can not allocate another PT instance.
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MBED_ASSERT(pwm.pin == pin);
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}
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// Enable the clock
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MXC_CLKMAN->clk_ctrl_2_pt = MXC_E_CLKMAN_CLK_SCALE_ENABLED;
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// Set the obj pointer to the propper PWM instance
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obj->pwm = (mxc_pt_regs_t*)pwm.peripheral;
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// Initialize object period and pulse width
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obj->period = -1;
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obj->pulse_width = -1;
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// Disable the output
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obj->pwm->train = 0x0;
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obj->pwm->rate_length = 0x0;
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// Configure the pin
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pin_mode(pin, (PinMode)PullNone);
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pin_function(pin, pwm.function);
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// default to 20ms: standard for servos, and fine for e.g. brightness control
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pwmout_period_us(obj, 20000);
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pwmout_write (obj, 0);
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// Set the drive mode to normal
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MXC_SET_FIELD(&MXC_GPIO->out_mode[port], (0x7 << (port_pin*4)), (MXC_V_GPIO_OUT_MODE_NORMAL_DRIVE << (port_pin*4)));
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// Enable the global pwm
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MXC_PTG->ctrl = MXC_F_PT_CTRL_ENABLE_ALL;
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}
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//******************************************************************************
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void pwmout_free(pwmout_t* obj)
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{
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// Set the registers to the reset value
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obj->pwm->train = 0;
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obj->pwm->rate_length = 0x08000000;
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}
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//******************************************************************************
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static void pwmout_update(pwmout_t* obj)
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{
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// Calculate and set the divider ratio
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int div = (obj->period * (SystemCoreClock/1000000))/32;
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if (div < 2){
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div = 2;
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}
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MXC_SET_FIELD(&obj->pwm->rate_length, MXC_F_PT_RATE_LENGTH_RATE_CONTROL, div);
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// Change the duty cycle to adjust the pulse width
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obj->pwm->train = (0xFFFFFFFF << (32-((32*obj->pulse_width)/obj->period)));
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}
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//******************************************************************************
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void pwmout_write(pwmout_t* obj, float percent)
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{
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// Saturate percent if outside of range
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if(percent < 0.0) {
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percent = 0.0;
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} else if(percent > 1.0) {
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percent = 1.0;
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}
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// Resize the pulse width to set the duty cycle
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pwmout_pulsewidth_us(obj, (int)(percent*obj->period));
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}
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//******************************************************************************
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float pwmout_read(pwmout_t* obj)
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{
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// Check for when pulsewidth or period equals 0
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if((obj->pulse_width == 0) || (obj->period == 0)){
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return 0;
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}
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// Return the duty cycle
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return ((float)obj->pulse_width / (float)obj->period);
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}
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//******************************************************************************
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void pwmout_period(pwmout_t* obj, float seconds)
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{
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pwmout_period_us(obj, (int)(seconds * 1000000.0));
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}
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//******************************************************************************
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void pwmout_period_ms(pwmout_t* obj, int ms)
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{
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pwmout_period_us(obj, ms*1000);
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}
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//******************************************************************************
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void pwmout_period_us(pwmout_t* obj, int us)
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{
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// Check the range of the period
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MBED_ASSERT((us >= 0) && (us <= (int)(SystemCoreClock/32)));
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// Set pulse width to half the period if uninitialized
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if(obj->pulse_width == -1){
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obj->pulse_width = us/2;
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}
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// Save the period
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obj->period = us;
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// Update the registers
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pwmout_update(obj);
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}
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//******************************************************************************
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void pwmout_pulsewidth(pwmout_t* obj, float seconds)
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{
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pwmout_pulsewidth_us(obj, (int)(seconds * 1000000.0));
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}
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//******************************************************************************
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void pwmout_pulsewidth_ms(pwmout_t* obj, int ms)
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{
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pwmout_pulsewidth_us(obj, ms*1000);
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}
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//******************************************************************************
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void pwmout_pulsewidth_us(pwmout_t* obj, int us)
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{
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// Check the range of the pulsewidth
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MBED_ASSERT((us >= 0) && (us <= (int)(SystemCoreClock/32)));
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// Initialize period to double the pulsewidth if uninitialized
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if(obj->period == -1){
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obj->period = 2*us;
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}
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// Save the pulsewidth
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obj->pulse_width = us;
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// Update the register
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pwmout_update(obj);
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}
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