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targets/TARGET_Maxim/TARGET_MAX32620/pwmout_api.c
- Committer:
- <>
- Date:
- 2016-10-28
- Revision:
- 149:156823d33999
File content as of revision 149:156823d33999:
/******************************************************************************* * Copyright (C) 2016 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 "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); MBED_ASSERT((pin_func < 1) || (pin_func > 3)); // Search through PinMap_PWM to find the pin while (pwm.pin != pin) { pwm = PinMap_PWM[++i]; } // Find a free PT instance on this pin while (pwm.pin == pin) { // Check to see if this PT instance is free if (((mxc_pt_regs_t*)pwm.peripheral)->rate_length & MXC_F_PT_RATE_LENGTH_MODE) { break; } pwm = PinMap_PWM[++i]; // Raise an assertion if we can not allocate another PT instance. MBED_ASSERT(pwm.pin == pin); } // Enable the clock MXC_CLKMAN->sys_clk_ctrl_7_pt = MXC_S_CLKMAN_CLK_SCALE_DIV_1; // 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); // Set the drive mode to normal MXC_SET_FIELD(&MXC_GPIO->out_mode[port], (0x7 << (port_pin*4)), (MXC_V_GPIO_OUT_MODE_NORMAL << (port_pin*4))); // Enable this PWM channel MXC_PTG->enable |= (1 << MXC_PT_GET_IDX(obj->pwm)); } //****************************************************************************** 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 < 0.0f) { percent = 0.0f; } else if(percent > 1.0f) { percent = 1.0f; } // 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 * 1000000.0f)); } //****************************************************************************** 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 * 1000000.0f)); } //****************************************************************************** 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); }