added prescaler for 16 bit pwm in LPC1347 target
Fork of mbed-dev by
targets/hal/TARGET_Maxim/TARGET_MAX32610/pwmout_api.c@0:9b334a45a8ff, 2015-10-01 (annotated)
- Committer:
- bogdanm
- Date:
- Thu Oct 01 15:25:22 2015 +0300
- Revision:
- 0:9b334a45a8ff
- Child:
- 144:ef7eb2e8f9f7
Initial commit on mbed-dev
Replaces mbed-src (now inactive)
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
bogdanm | 0:9b334a45a8ff | 1 | /******************************************************************************* |
bogdanm | 0:9b334a45a8ff | 2 | * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved. |
bogdanm | 0:9b334a45a8ff | 3 | * |
bogdanm | 0:9b334a45a8ff | 4 | * Permission is hereby granted, free of charge, to any person obtaining a |
bogdanm | 0:9b334a45a8ff | 5 | * copy of this software and associated documentation files (the "Software"), |
bogdanm | 0:9b334a45a8ff | 6 | * to deal in the Software without restriction, including without limitation |
bogdanm | 0:9b334a45a8ff | 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
bogdanm | 0:9b334a45a8ff | 8 | * and/or sell copies of the Software, and to permit persons to whom the |
bogdanm | 0:9b334a45a8ff | 9 | * Software is furnished to do so, subject to the following conditions: |
bogdanm | 0:9b334a45a8ff | 10 | * |
bogdanm | 0:9b334a45a8ff | 11 | * The above copyright notice and this permission notice shall be included |
bogdanm | 0:9b334a45a8ff | 12 | * in all copies or substantial portions of the Software. |
bogdanm | 0:9b334a45a8ff | 13 | * |
bogdanm | 0:9b334a45a8ff | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
bogdanm | 0:9b334a45a8ff | 15 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
bogdanm | 0:9b334a45a8ff | 16 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
bogdanm | 0:9b334a45a8ff | 17 | * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES |
bogdanm | 0:9b334a45a8ff | 18 | * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
bogdanm | 0:9b334a45a8ff | 19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
bogdanm | 0:9b334a45a8ff | 20 | * OTHER DEALINGS IN THE SOFTWARE. |
bogdanm | 0:9b334a45a8ff | 21 | * |
bogdanm | 0:9b334a45a8ff | 22 | * Except as contained in this notice, the name of Maxim Integrated |
bogdanm | 0:9b334a45a8ff | 23 | * Products, Inc. shall not be used except as stated in the Maxim Integrated |
bogdanm | 0:9b334a45a8ff | 24 | * Products, Inc. Branding Policy. |
bogdanm | 0:9b334a45a8ff | 25 | * |
bogdanm | 0:9b334a45a8ff | 26 | * The mere transfer of this software does not imply any licenses |
bogdanm | 0:9b334a45a8ff | 27 | * of trade secrets, proprietary technology, copyrights, patents, |
bogdanm | 0:9b334a45a8ff | 28 | * trademarks, maskwork rights, or any other form of intellectual |
bogdanm | 0:9b334a45a8ff | 29 | * property whatsoever. Maxim Integrated Products, Inc. retains all |
bogdanm | 0:9b334a45a8ff | 30 | * ownership rights. |
bogdanm | 0:9b334a45a8ff | 31 | ******************************************************************************* |
bogdanm | 0:9b334a45a8ff | 32 | */ |
bogdanm | 0:9b334a45a8ff | 33 | |
bogdanm | 0:9b334a45a8ff | 34 | #include "mbed_assert.h" |
bogdanm | 0:9b334a45a8ff | 35 | #include "cmsis.h" |
bogdanm | 0:9b334a45a8ff | 36 | #include "pwmout_api.h" |
bogdanm | 0:9b334a45a8ff | 37 | #include "pinmap.h" |
bogdanm | 0:9b334a45a8ff | 38 | #include "ioman_regs.h" |
bogdanm | 0:9b334a45a8ff | 39 | #include "clkman_regs.h" |
bogdanm | 0:9b334a45a8ff | 40 | #include "PeripheralPins.h" |
bogdanm | 0:9b334a45a8ff | 41 | |
bogdanm | 0:9b334a45a8ff | 42 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 43 | void pwmout_init(pwmout_t* obj, PinName pin) |
bogdanm | 0:9b334a45a8ff | 44 | { |
bogdanm | 0:9b334a45a8ff | 45 | // Make sure the pin is free for GPIO use |
bogdanm | 0:9b334a45a8ff | 46 | unsigned int port = (unsigned int)pin >> PORT_SHIFT; |
bogdanm | 0:9b334a45a8ff | 47 | unsigned int port_pin = (unsigned int)pin & ~(0xFFFFFFFF << PORT_SHIFT); |
bogdanm | 0:9b334a45a8ff | 48 | MBED_ASSERT(MXC_GPIO->free[port] & (0x1 << port_pin)); |
bogdanm | 0:9b334a45a8ff | 49 | |
bogdanm | 0:9b334a45a8ff | 50 | int i = 0; |
bogdanm | 0:9b334a45a8ff | 51 | PinMap pwm = PinMap_PWM[0]; |
bogdanm | 0:9b334a45a8ff | 52 | |
bogdanm | 0:9b334a45a8ff | 53 | // Check if there is a pulse train already active on this port |
bogdanm | 0:9b334a45a8ff | 54 | int pin_func = (MXC_GPIO->func_sel[port] & (0xF << (port_pin*4))) >> (port_pin*4); |
bogdanm | 0:9b334a45a8ff | 55 | MBED_ASSERT((pin_func < 1) || (pin_func > 3)); |
bogdanm | 0:9b334a45a8ff | 56 | |
bogdanm | 0:9b334a45a8ff | 57 | // Search through PinMap_PWM to find the pin |
bogdanm | 0:9b334a45a8ff | 58 | while(pwm.pin != pin) { |
bogdanm | 0:9b334a45a8ff | 59 | pwm = PinMap_PWM[++i]; |
bogdanm | 0:9b334a45a8ff | 60 | } |
bogdanm | 0:9b334a45a8ff | 61 | |
bogdanm | 0:9b334a45a8ff | 62 | // Find a free PT instance on this pin |
bogdanm | 0:9b334a45a8ff | 63 | while(pwm.pin == pin) { |
bogdanm | 0:9b334a45a8ff | 64 | |
bogdanm | 0:9b334a45a8ff | 65 | // Check to see if this PT instance is free |
bogdanm | 0:9b334a45a8ff | 66 | if((((mxc_pt_regs_t*)pwm.peripheral)->rate_length & |
bogdanm | 0:9b334a45a8ff | 67 | MXC_F_PT_RATE_LENGTH_MODE)) { |
bogdanm | 0:9b334a45a8ff | 68 | break; |
bogdanm | 0:9b334a45a8ff | 69 | } |
bogdanm | 0:9b334a45a8ff | 70 | |
bogdanm | 0:9b334a45a8ff | 71 | pwm = PinMap_PWM[++i]; |
bogdanm | 0:9b334a45a8ff | 72 | |
bogdanm | 0:9b334a45a8ff | 73 | // Raise an assertion if we can not allocate another PT instance. |
bogdanm | 0:9b334a45a8ff | 74 | MBED_ASSERT(pwm.pin == pin); |
bogdanm | 0:9b334a45a8ff | 75 | } |
bogdanm | 0:9b334a45a8ff | 76 | |
bogdanm | 0:9b334a45a8ff | 77 | // Enable the clock |
bogdanm | 0:9b334a45a8ff | 78 | MXC_CLKMAN->clk_ctrl_2_pt = MXC_E_CLKMAN_CLK_SCALE_ENABLED; |
bogdanm | 0:9b334a45a8ff | 79 | |
bogdanm | 0:9b334a45a8ff | 80 | // Set the obj pointer to the propper PWM instance |
bogdanm | 0:9b334a45a8ff | 81 | obj->pwm = (mxc_pt_regs_t*)pwm.peripheral; |
bogdanm | 0:9b334a45a8ff | 82 | |
bogdanm | 0:9b334a45a8ff | 83 | // Initialize object period and pulse width |
bogdanm | 0:9b334a45a8ff | 84 | obj->period = -1; |
bogdanm | 0:9b334a45a8ff | 85 | obj->pulse_width = -1; |
bogdanm | 0:9b334a45a8ff | 86 | |
bogdanm | 0:9b334a45a8ff | 87 | // Disable the output |
bogdanm | 0:9b334a45a8ff | 88 | obj->pwm->train = 0x0; |
bogdanm | 0:9b334a45a8ff | 89 | obj->pwm->rate_length = 0x0; |
bogdanm | 0:9b334a45a8ff | 90 | |
bogdanm | 0:9b334a45a8ff | 91 | // Configure the pin |
bogdanm | 0:9b334a45a8ff | 92 | pin_mode(pin, (PinMode)PullNone); |
bogdanm | 0:9b334a45a8ff | 93 | pin_function(pin, pwm.function); |
bogdanm | 0:9b334a45a8ff | 94 | |
bogdanm | 0:9b334a45a8ff | 95 | // default to 20ms: standard for servos, and fine for e.g. brightness control |
bogdanm | 0:9b334a45a8ff | 96 | pwmout_period_us(obj, 20000); |
bogdanm | 0:9b334a45a8ff | 97 | pwmout_write (obj, 0); |
bogdanm | 0:9b334a45a8ff | 98 | |
bogdanm | 0:9b334a45a8ff | 99 | // Set the drive mode to normal |
bogdanm | 0:9b334a45a8ff | 100 | MXC_SET_FIELD(&MXC_GPIO->out_mode[port], (0x7 << (port_pin*4)), (MXC_V_GPIO_OUT_MODE_NORMAL_DRIVE << (port_pin*4))); |
bogdanm | 0:9b334a45a8ff | 101 | |
bogdanm | 0:9b334a45a8ff | 102 | // Enable the global pwm |
bogdanm | 0:9b334a45a8ff | 103 | MXC_PTG->ctrl = MXC_F_PT_CTRL_ENABLE_ALL; |
bogdanm | 0:9b334a45a8ff | 104 | } |
bogdanm | 0:9b334a45a8ff | 105 | |
bogdanm | 0:9b334a45a8ff | 106 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 107 | void pwmout_free(pwmout_t* obj) |
bogdanm | 0:9b334a45a8ff | 108 | { |
bogdanm | 0:9b334a45a8ff | 109 | // Set the registers to the reset value |
bogdanm | 0:9b334a45a8ff | 110 | obj->pwm->train = 0; |
bogdanm | 0:9b334a45a8ff | 111 | obj->pwm->rate_length = 0x08000000; |
bogdanm | 0:9b334a45a8ff | 112 | } |
bogdanm | 0:9b334a45a8ff | 113 | |
bogdanm | 0:9b334a45a8ff | 114 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 115 | static void pwmout_update(pwmout_t* obj) |
bogdanm | 0:9b334a45a8ff | 116 | { |
bogdanm | 0:9b334a45a8ff | 117 | // Calculate and set the divider ratio |
bogdanm | 0:9b334a45a8ff | 118 | int div = (obj->period * (SystemCoreClock/1000000))/32; |
bogdanm | 0:9b334a45a8ff | 119 | if (div < 2){ |
bogdanm | 0:9b334a45a8ff | 120 | div = 2; |
bogdanm | 0:9b334a45a8ff | 121 | } |
bogdanm | 0:9b334a45a8ff | 122 | MXC_SET_FIELD(&obj->pwm->rate_length, MXC_F_PT_RATE_LENGTH_RATE_CONTROL, div); |
bogdanm | 0:9b334a45a8ff | 123 | |
bogdanm | 0:9b334a45a8ff | 124 | // Change the duty cycle to adjust the pulse width |
bogdanm | 0:9b334a45a8ff | 125 | obj->pwm->train = (0xFFFFFFFF << (32-((32*obj->pulse_width)/obj->period))); |
bogdanm | 0:9b334a45a8ff | 126 | } |
bogdanm | 0:9b334a45a8ff | 127 | |
bogdanm | 0:9b334a45a8ff | 128 | |
bogdanm | 0:9b334a45a8ff | 129 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 130 | void pwmout_write(pwmout_t* obj, float percent) |
bogdanm | 0:9b334a45a8ff | 131 | { |
bogdanm | 0:9b334a45a8ff | 132 | // Saturate percent if outside of range |
bogdanm | 0:9b334a45a8ff | 133 | if(percent < 0.0) { |
bogdanm | 0:9b334a45a8ff | 134 | percent = 0.0; |
bogdanm | 0:9b334a45a8ff | 135 | } else if(percent > 1.0) { |
bogdanm | 0:9b334a45a8ff | 136 | percent = 1.0; |
bogdanm | 0:9b334a45a8ff | 137 | } |
bogdanm | 0:9b334a45a8ff | 138 | |
bogdanm | 0:9b334a45a8ff | 139 | // Resize the pulse width to set the duty cycle |
bogdanm | 0:9b334a45a8ff | 140 | pwmout_pulsewidth_us(obj, (int)(percent*obj->period)); |
bogdanm | 0:9b334a45a8ff | 141 | } |
bogdanm | 0:9b334a45a8ff | 142 | |
bogdanm | 0:9b334a45a8ff | 143 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 144 | float pwmout_read(pwmout_t* obj) |
bogdanm | 0:9b334a45a8ff | 145 | { |
bogdanm | 0:9b334a45a8ff | 146 | // Check for when pulsewidth or period equals 0 |
bogdanm | 0:9b334a45a8ff | 147 | if((obj->pulse_width == 0) || (obj->period == 0)){ |
bogdanm | 0:9b334a45a8ff | 148 | return 0; |
bogdanm | 0:9b334a45a8ff | 149 | } |
bogdanm | 0:9b334a45a8ff | 150 | |
bogdanm | 0:9b334a45a8ff | 151 | // Return the duty cycle |
bogdanm | 0:9b334a45a8ff | 152 | return ((float)obj->pulse_width / (float)obj->period); |
bogdanm | 0:9b334a45a8ff | 153 | } |
bogdanm | 0:9b334a45a8ff | 154 | |
bogdanm | 0:9b334a45a8ff | 155 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 156 | void pwmout_period(pwmout_t* obj, float seconds) |
bogdanm | 0:9b334a45a8ff | 157 | { |
bogdanm | 0:9b334a45a8ff | 158 | pwmout_period_us(obj, (int)(seconds * 1000000.0)); |
bogdanm | 0:9b334a45a8ff | 159 | } |
bogdanm | 0:9b334a45a8ff | 160 | |
bogdanm | 0:9b334a45a8ff | 161 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 162 | void pwmout_period_ms(pwmout_t* obj, int ms) |
bogdanm | 0:9b334a45a8ff | 163 | { |
bogdanm | 0:9b334a45a8ff | 164 | pwmout_period_us(obj, ms*1000); |
bogdanm | 0:9b334a45a8ff | 165 | } |
bogdanm | 0:9b334a45a8ff | 166 | |
bogdanm | 0:9b334a45a8ff | 167 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 168 | void pwmout_period_us(pwmout_t* obj, int us) |
bogdanm | 0:9b334a45a8ff | 169 | { |
bogdanm | 0:9b334a45a8ff | 170 | // Check the range of the period |
bogdanm | 0:9b334a45a8ff | 171 | MBED_ASSERT((us >= 0) && (us <= (int)(SystemCoreClock/32))); |
bogdanm | 0:9b334a45a8ff | 172 | |
bogdanm | 0:9b334a45a8ff | 173 | // Set pulse width to half the period if uninitialized |
bogdanm | 0:9b334a45a8ff | 174 | if(obj->pulse_width == -1){ |
bogdanm | 0:9b334a45a8ff | 175 | obj->pulse_width = us/2; |
bogdanm | 0:9b334a45a8ff | 176 | } |
bogdanm | 0:9b334a45a8ff | 177 | |
bogdanm | 0:9b334a45a8ff | 178 | // Save the period |
bogdanm | 0:9b334a45a8ff | 179 | obj->period = us; |
bogdanm | 0:9b334a45a8ff | 180 | |
bogdanm | 0:9b334a45a8ff | 181 | // Update the registers |
bogdanm | 0:9b334a45a8ff | 182 | pwmout_update(obj); |
bogdanm | 0:9b334a45a8ff | 183 | } |
bogdanm | 0:9b334a45a8ff | 184 | |
bogdanm | 0:9b334a45a8ff | 185 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 186 | void pwmout_pulsewidth(pwmout_t* obj, float seconds) |
bogdanm | 0:9b334a45a8ff | 187 | { |
bogdanm | 0:9b334a45a8ff | 188 | pwmout_pulsewidth_us(obj, (int)(seconds * 1000000.0)); |
bogdanm | 0:9b334a45a8ff | 189 | } |
bogdanm | 0:9b334a45a8ff | 190 | |
bogdanm | 0:9b334a45a8ff | 191 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 192 | void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) |
bogdanm | 0:9b334a45a8ff | 193 | { |
bogdanm | 0:9b334a45a8ff | 194 | pwmout_pulsewidth_us(obj, ms*1000); |
bogdanm | 0:9b334a45a8ff | 195 | } |
bogdanm | 0:9b334a45a8ff | 196 | |
bogdanm | 0:9b334a45a8ff | 197 | //****************************************************************************** |
bogdanm | 0:9b334a45a8ff | 198 | void pwmout_pulsewidth_us(pwmout_t* obj, int us) |
bogdanm | 0:9b334a45a8ff | 199 | { |
bogdanm | 0:9b334a45a8ff | 200 | // Check the range of the pulsewidth |
bogdanm | 0:9b334a45a8ff | 201 | MBED_ASSERT((us >= 0) && (us <= (int)(SystemCoreClock/32))); |
bogdanm | 0:9b334a45a8ff | 202 | |
bogdanm | 0:9b334a45a8ff | 203 | // Initialize period to double the pulsewidth if uninitialized |
bogdanm | 0:9b334a45a8ff | 204 | if(obj->period == -1){ |
bogdanm | 0:9b334a45a8ff | 205 | obj->period = 2*us; |
bogdanm | 0:9b334a45a8ff | 206 | } |
bogdanm | 0:9b334a45a8ff | 207 | |
bogdanm | 0:9b334a45a8ff | 208 | // Save the pulsewidth |
bogdanm | 0:9b334a45a8ff | 209 | obj->pulse_width = us; |
bogdanm | 0:9b334a45a8ff | 210 | |
bogdanm | 0:9b334a45a8ff | 211 | // Update the register |
bogdanm | 0:9b334a45a8ff | 212 | pwmout_update(obj); |
bogdanm | 0:9b334a45a8ff | 213 | } |