Fawwaz Nadzmy / mbed-STM

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by mbed official

targets/TARGET_Maxim/TARGET_MAX32620/pwmout_api.c@153:9398a535854b, 2016-12-22 (annotated)

Committer:
fwndz
Date:
Thu Dec 22 05:12:40 2016 +0000
Revision:
153:9398a535854b
Parent:
149:156823d33999 
device target maximize

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 149:156823d33999 1 /*******************************************************************************
<> 149:156823d33999 2 * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
<> 149:156823d33999 3 *
<> 149:156823d33999 4 * Permission is hereby granted, free of charge, to any person obtaining a
<> 149:156823d33999 5 * copy of this software and associated documentation files (the "Software"),
<> 149:156823d33999 6 * to deal in the Software without restriction, including without limitation
<> 149:156823d33999 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
<> 149:156823d33999 8 * and/or sell copies of the Software, and to permit persons to whom the
<> 149:156823d33999 9 * Software is furnished to do so, subject to the following conditions:
<> 149:156823d33999 10 *
<> 149:156823d33999 11 * The above copyright notice and this permission notice shall be included
<> 149:156823d33999 12 * in all copies or substantial portions of the Software.
<> 149:156823d33999 13 *
<> 149:156823d33999 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
<> 149:156823d33999 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
<> 149:156823d33999 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
<> 149:156823d33999 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
<> 149:156823d33999 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
<> 149:156823d33999 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
<> 149:156823d33999 20 * OTHER DEALINGS IN THE SOFTWARE.
<> 149:156823d33999 21 *
<> 149:156823d33999 22 * Except as contained in this notice, the name of Maxim Integrated
<> 149:156823d33999 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
<> 149:156823d33999 24 * Products, Inc. Branding Policy.
<> 149:156823d33999 25 *
<> 149:156823d33999 26 * The mere transfer of this software does not imply any licenses
<> 149:156823d33999 27 * of trade secrets, proprietary technology, copyrights, patents,
<> 149:156823d33999 28 * trademarks, maskwork rights, or any other form of intellectual
<> 149:156823d33999 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
<> 149:156823d33999 30 * ownership rights.
<> 149:156823d33999 31 *******************************************************************************
<> 149:156823d33999 32 */
<> 149:156823d33999 33
<> 149:156823d33999 34 #include "mbed_assert.h"
<> 149:156823d33999 35 #include "cmsis.h"
<> 149:156823d33999 36 #include "pwmout_api.h"
<> 149:156823d33999 37 #include "pinmap.h"
<> 149:156823d33999 38 #include "clkman_regs.h"
<> 149:156823d33999 39 #include "PeripheralPins.h"
<> 149:156823d33999 40
<> 149:156823d33999 41 //******************************************************************************
<> 149:156823d33999 42 void pwmout_init(pwmout_t* obj, PinName pin)
<> 149:156823d33999 43 {
<> 149:156823d33999 44 // Make sure the pin is free for GPIO use
<> 149:156823d33999 45 unsigned int port = (unsigned int)pin >> PORT_SHIFT;
<> 149:156823d33999 46 unsigned int port_pin = (unsigned int)pin & ~(0xFFFFFFFF << PORT_SHIFT);
<> 149:156823d33999 47 MBED_ASSERT(MXC_GPIO->free[port] & (0x1 << port_pin));
<> 149:156823d33999 48
<> 149:156823d33999 49 int i = 0;
<> 149:156823d33999 50 PinMap pwm = PinMap_PWM[0];
<> 149:156823d33999 51
<> 149:156823d33999 52 // Check if there is a pulse train already active on this port
<> 149:156823d33999 53 int pin_func = (MXC_GPIO->func_sel[port] & (0xF << (port_pin*4))) >> (port_pin*4);
<> 149:156823d33999 54 MBED_ASSERT((pin_func < 1) || (pin_func > 3));
<> 149:156823d33999 55
<> 149:156823d33999 56 // Search through PinMap_PWM to find the pin
<> 149:156823d33999 57 while (pwm.pin != pin) {
<> 149:156823d33999 58 pwm = PinMap_PWM[++i];
<> 149:156823d33999 59 }
<> 149:156823d33999 60
<> 149:156823d33999 61 // Find a free PT instance on this pin
<> 149:156823d33999 62 while (pwm.pin == pin) {
<> 149:156823d33999 63
<> 149:156823d33999 64 // Check to see if this PT instance is free
<> 149:156823d33999 65 if (((mxc_pt_regs_t*)pwm.peripheral)->rate_length & MXC_F_PT_RATE_LENGTH_MODE) {
<> 149:156823d33999 66 break;
<> 149:156823d33999 67 }
<> 149:156823d33999 68
<> 149:156823d33999 69 pwm = PinMap_PWM[++i];
<> 149:156823d33999 70
<> 149:156823d33999 71 // Raise an assertion if we can not allocate another PT instance.
<> 149:156823d33999 72 MBED_ASSERT(pwm.pin == pin);
<> 149:156823d33999 73 }
<> 149:156823d33999 74
<> 149:156823d33999 75 // Enable the clock
<> 149:156823d33999 76 MXC_CLKMAN->sys_clk_ctrl_7_pt = MXC_S_CLKMAN_CLK_SCALE_DIV_1;
<> 149:156823d33999 77
<> 149:156823d33999 78 // Set the obj pointer to the propper PWM instance
<> 149:156823d33999 79 obj->pwm = (mxc_pt_regs_t*)pwm.peripheral;
<> 149:156823d33999 80
<> 149:156823d33999 81 // Initialize object period and pulse width
<> 149:156823d33999 82 obj->period = -1;
<> 149:156823d33999 83 obj->pulse_width = -1;
<> 149:156823d33999 84
<> 149:156823d33999 85 // Disable the output
<> 149:156823d33999 86 obj->pwm->train = 0x0;
<> 149:156823d33999 87 obj->pwm->rate_length = 0x0;
<> 149:156823d33999 88
<> 149:156823d33999 89 // Configure the pin
<> 149:156823d33999 90 pin_mode(pin, (PinMode)PullNone);
<> 149:156823d33999 91 pin_function(pin, pwm.function);
<> 149:156823d33999 92
<> 149:156823d33999 93 // default to 20ms: standard for servos, and fine for e.g. brightness control
<> 149:156823d33999 94 pwmout_period_us(obj, 20000);
<> 149:156823d33999 95 pwmout_write (obj, 0);
<> 149:156823d33999 96
<> 149:156823d33999 97 // Set the drive mode to normal
<> 149:156823d33999 98 MXC_SET_FIELD(&MXC_GPIO->out_mode[port], (0x7 << (port_pin*4)), (MXC_V_GPIO_OUT_MODE_NORMAL << (port_pin*4)));
<> 149:156823d33999 99
<> 149:156823d33999 100 // Enable this PWM channel
<> 149:156823d33999 101 MXC_PTG->enable |= (1 << MXC_PT_GET_IDX(obj->pwm));
<> 149:156823d33999 102 }
<> 149:156823d33999 103
<> 149:156823d33999 104 //******************************************************************************
<> 149:156823d33999 105 void pwmout_free(pwmout_t* obj)
<> 149:156823d33999 106 {
<> 149:156823d33999 107 // Set the registers to the reset value
<> 149:156823d33999 108 obj->pwm->train = 0;
<> 149:156823d33999 109 obj->pwm->rate_length = 0x08000000;
<> 149:156823d33999 110 }
<> 149:156823d33999 111
<> 149:156823d33999 112 //******************************************************************************
<> 149:156823d33999 113 static void pwmout_update(pwmout_t* obj)
<> 149:156823d33999 114 {
<> 149:156823d33999 115 // Calculate and set the divider ratio
<> 149:156823d33999 116 int div = (obj->period * (SystemCoreClock/1000000))/32;
<> 149:156823d33999 117 if (div < 2) {
<> 149:156823d33999 118 div = 2;
<> 149:156823d33999 119 }
<> 149:156823d33999 120 MXC_SET_FIELD(&obj->pwm->rate_length, MXC_F_PT_RATE_LENGTH_RATE_CONTROL, div);
<> 149:156823d33999 121
<> 149:156823d33999 122 // Change the duty cycle to adjust the pulse width
<> 149:156823d33999 123 obj->pwm->train = (0xFFFFFFFF << (32-((32*obj->pulse_width)/obj->period)));
<> 149:156823d33999 124 }
<> 149:156823d33999 125
<> 149:156823d33999 126
<> 149:156823d33999 127 //******************************************************************************
<> 149:156823d33999 128 void pwmout_write(pwmout_t* obj, float percent)
<> 149:156823d33999 129 {
<> 149:156823d33999 130 // Saturate percent if outside of range
<> 149:156823d33999 131 if (percent < 0.0f) {
<> 149:156823d33999 132 percent = 0.0f;
<> 149:156823d33999 133 } else if(percent > 1.0f) {
<> 149:156823d33999 134 percent = 1.0f;
<> 149:156823d33999 135 }
<> 149:156823d33999 136
<> 149:156823d33999 137 // Resize the pulse width to set the duty cycle
<> 149:156823d33999 138 pwmout_pulsewidth_us(obj, (int)(percent*obj->period));
<> 149:156823d33999 139 }
<> 149:156823d33999 140
<> 149:156823d33999 141 //******************************************************************************
<> 149:156823d33999 142 float pwmout_read(pwmout_t* obj)
<> 149:156823d33999 143 {
<> 149:156823d33999 144 // Check for when pulsewidth or period equals 0
<> 149:156823d33999 145 if ((obj->pulse_width == 0) || (obj->period == 0)) {
<> 149:156823d33999 146 return 0;
<> 149:156823d33999 147 }
<> 149:156823d33999 148
<> 149:156823d33999 149 // Return the duty cycle
<> 149:156823d33999 150 return ((float)obj->pulse_width / (float)obj->period);
<> 149:156823d33999 151 }
<> 149:156823d33999 152
<> 149:156823d33999 153 //******************************************************************************
<> 149:156823d33999 154 void pwmout_period(pwmout_t* obj, float seconds)
<> 149:156823d33999 155 {
<> 149:156823d33999 156 pwmout_period_us(obj, (int)(seconds * 1000000.0f));
<> 149:156823d33999 157 }
<> 149:156823d33999 158
<> 149:156823d33999 159 //******************************************************************************
<> 149:156823d33999 160 void pwmout_period_ms(pwmout_t* obj, int ms)
<> 149:156823d33999 161 {
<> 149:156823d33999 162 pwmout_period_us(obj, ms*1000);
<> 149:156823d33999 163 }
<> 149:156823d33999 164
<> 149:156823d33999 165 //******************************************************************************
<> 149:156823d33999 166 void pwmout_period_us(pwmout_t* obj, int us)
<> 149:156823d33999 167 {
<> 149:156823d33999 168 // Check the range of the period
<> 149:156823d33999 169 MBED_ASSERT((us >= 0) && (us <= (int)(SystemCoreClock/32)));
<> 149:156823d33999 170
<> 149:156823d33999 171 // Set pulse width to half the period if uninitialized
<> 149:156823d33999 172 if (obj->pulse_width == -1) {
<> 149:156823d33999 173 obj->pulse_width = us/2;
<> 149:156823d33999 174 }
<> 149:156823d33999 175
<> 149:156823d33999 176 // Save the period
<> 149:156823d33999 177 obj->period = us;
<> 149:156823d33999 178
<> 149:156823d33999 179 // Update the registers
<> 149:156823d33999 180 pwmout_update(obj);
<> 149:156823d33999 181 }
<> 149:156823d33999 182
<> 149:156823d33999 183 //******************************************************************************
<> 149:156823d33999 184 void pwmout_pulsewidth(pwmout_t* obj, float seconds)
<> 149:156823d33999 185 {
<> 149:156823d33999 186 pwmout_pulsewidth_us(obj, (int)(seconds * 1000000.0f));
<> 149:156823d33999 187 }
<> 149:156823d33999 188
<> 149:156823d33999 189 //******************************************************************************
<> 149:156823d33999 190 void pwmout_pulsewidth_ms(pwmout_t* obj, int ms)
<> 149:156823d33999 191 {
<> 149:156823d33999 192 pwmout_pulsewidth_us(obj, ms*1000);
<> 149:156823d33999 193 }
<> 149:156823d33999 194
<> 149:156823d33999 195 //******************************************************************************
<> 149:156823d33999 196 void pwmout_pulsewidth_us(pwmout_t* obj, int us)
<> 149:156823d33999 197 {
<> 149:156823d33999 198 // Check the range of the pulsewidth
<> 149:156823d33999 199 MBED_ASSERT((us >= 0) && (us <= (int)(SystemCoreClock/32)));
<> 149:156823d33999 200
<> 149:156823d33999 201 // Initialize period to double the pulsewidth if uninitialized
<> 149:156823d33999 202 if (obj->period == -1) {
<> 149:156823d33999 203 obj->period = 2*us;
<> 149:156823d33999 204 }
<> 149:156823d33999 205
<> 149:156823d33999 206 // Save the pulsewidth
<> 149:156823d33999 207 obj->pulse_width = us;
<> 149:156823d33999 208
<> 149:156823d33999 209 // Update the register
<> 149:156823d33999 210 pwmout_update(obj);
<> 149:156823d33999 211 }