Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

targets/hal/TARGET_Maxim/TARGET_MAX32620/analogin_api.c@147:ba84b7dc41a7, 2016-09-10 (annotated)

Committer:
JojoS
Date:
Sat Sep 10 15:32:04 2016 +0000
Revision:
147:ba84b7dc41a7
Parent:
144:ef7eb2e8f9f7 
added prescaler for 16 bit timers (solution as in LPC11xx), default prescaler 31 for max 28 ms period time

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /*******************************************************************************
<> 144:ef7eb2e8f9f7 2 * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Permission is hereby granted, free of charge, to any person obtaining a
<> 144:ef7eb2e8f9f7 5 * copy of this software and associated documentation files (the "Software"),
<> 144:ef7eb2e8f9f7 6 * to deal in the Software without restriction, including without limitation
<> 144:ef7eb2e8f9f7 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
<> 144:ef7eb2e8f9f7 8 * and/or sell copies of the Software, and to permit persons to whom the
<> 144:ef7eb2e8f9f7 9 * Software is furnished to do so, subject to the following conditions:
<> 144:ef7eb2e8f9f7 10 *
<> 144:ef7eb2e8f9f7 11 * The above copyright notice and this permission notice shall be included
<> 144:ef7eb2e8f9f7 12 * in all copies or substantial portions of the Software.
<> 144:ef7eb2e8f9f7 13 *
<> 144:ef7eb2e8f9f7 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
<> 144:ef7eb2e8f9f7 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
<> 144:ef7eb2e8f9f7 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
<> 144:ef7eb2e8f9f7 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
<> 144:ef7eb2e8f9f7 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
<> 144:ef7eb2e8f9f7 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
<> 144:ef7eb2e8f9f7 20 * OTHER DEALINGS IN THE SOFTWARE.
<> 144:ef7eb2e8f9f7 21 *
<> 144:ef7eb2e8f9f7 22 * Except as contained in this notice, the name of Maxim Integrated
<> 144:ef7eb2e8f9f7 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
<> 144:ef7eb2e8f9f7 24 * Products, Inc. Branding Policy.
<> 144:ef7eb2e8f9f7 25 *
<> 144:ef7eb2e8f9f7 26 * The mere transfer of this software does not imply any licenses
<> 144:ef7eb2e8f9f7 27 * of trade secrets, proprietary technology, copyrights, patents,
<> 144:ef7eb2e8f9f7 28 * trademarks, maskwork rights, or any other form of intellectual
<> 144:ef7eb2e8f9f7 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
<> 144:ef7eb2e8f9f7 30 * ownership rights.
<> 144:ef7eb2e8f9f7 31 *******************************************************************************
<> 144:ef7eb2e8f9f7 32 */
<> 144:ef7eb2e8f9f7 33
<> 144:ef7eb2e8f9f7 34 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 35 #include "analogin_api.h"
<> 144:ef7eb2e8f9f7 36 #include "clkman_regs.h"
<> 144:ef7eb2e8f9f7 37 #include "pwrman_regs.h"
<> 144:ef7eb2e8f9f7 38 #include "trim_regs.h"
<> 144:ef7eb2e8f9f7 39 #include "PeripheralPins.h"
<> 144:ef7eb2e8f9f7 40
<> 144:ef7eb2e8f9f7 41 #define PGA_TRK_CNT 0x1F
<> 144:ef7eb2e8f9f7 42 #define ADC_ACT_CNT 0x1
<> 144:ef7eb2e8f9f7 43 #define ADC_PGA_CNT 0x1
<> 144:ef7eb2e8f9f7 44 #define ADC_ACQ_CNT 0x1
<> 144:ef7eb2e8f9f7 45 #define ADC_SLP_CNT 0x1
<> 144:ef7eb2e8f9f7 46
<> 144:ef7eb2e8f9f7 47 #define ADC_FULL_SCALE 0x3FF
<> 144:ef7eb2e8f9f7 48 #define ADC_EXTERNAL_LAST_INPUT 3
<> 144:ef7eb2e8f9f7 49
<> 144:ef7eb2e8f9f7 50 // Only allow initialization once
<> 144:ef7eb2e8f9f7 51 static int initialized = 0;
<> 144:ef7eb2e8f9f7 52
<> 144:ef7eb2e8f9f7 53 //******************************************************************************
<> 144:ef7eb2e8f9f7 54 void analogin_init(analogin_t *obj, PinName pin)
<> 144:ef7eb2e8f9f7 55 {
<> 144:ef7eb2e8f9f7 56 // Make sure pin is an analog pin we can use for ADC
<> 144:ef7eb2e8f9f7 57 MBED_ASSERT((ADCName)pinmap_peripheral(pin, PinMap_ADC) != (ADCName)NC);
<> 144:ef7eb2e8f9f7 58
<> 144:ef7eb2e8f9f7 59 // Set the object pointer
<> 144:ef7eb2e8f9f7 60 obj->adc = MXC_ADC;
<> 144:ef7eb2e8f9f7 61 obj->adc_pin = pin;
<> 144:ef7eb2e8f9f7 62
<> 144:ef7eb2e8f9f7 63 if (initialized == 0) {
<> 144:ef7eb2e8f9f7 64 // Enable AFE power
<> 144:ef7eb2e8f9f7 65 MXC_PWRMAN->pwr_rst_ctrl |= MXC_F_PWRMAN_PWR_RST_CTRL_AFE_POWERED;
<> 144:ef7eb2e8f9f7 66
<> 144:ef7eb2e8f9f7 67 // Enable the clock
<> 144:ef7eb2e8f9f7 68 MXC_CLKMAN->clk_ctrl |= MXC_F_CLKMAN_CLK_CTRL_ADC_CLOCK_ENABLE;
<> 144:ef7eb2e8f9f7 69
<> 144:ef7eb2e8f9f7 70 // Enable clock gate
<> 144:ef7eb2e8f9f7 71 MXC_CLKMAN->clk_gate_ctrl2 |= MXC_F_CLKMAN_CLK_GATE_CTRL2_ADC_CLK_GATER;
<> 144:ef7eb2e8f9f7 72
<> 144:ef7eb2e8f9f7 73 // Enable interface clock
<> 144:ef7eb2e8f9f7 74 obj->adc->ctrl |= MXC_F_ADC_CTRL_ADC_CLK_EN;
<> 144:ef7eb2e8f9f7 75
<> 144:ef7eb2e8f9f7 76 if ((MXC_TRIM->reg11_adc_trim0 == 0xFFFFFFFF) && (MXC_TRIM->reg12_adc_trim1 == 0xFFFFFFFF)) {
<> 144:ef7eb2e8f9f7 77 // Set default trim for untrimmed parts.
<> 144:ef7eb2e8f9f7 78 MXC_TRIM->reg11_adc_trim0 = 0x02000200;
<> 144:ef7eb2e8f9f7 79 MXC_TRIM->reg12_adc_trim1 = 0x02000200;
<> 144:ef7eb2e8f9f7 80 }
<> 144:ef7eb2e8f9f7 81
<> 144:ef7eb2e8f9f7 82 // Clear ADC ready interrupt (wite 1 to clr)
<> 144:ef7eb2e8f9f7 83 obj->adc->intr = (obj->adc->intr & 0xFFFF) | MXC_F_ADC_INTR_ADC_REF_READY_IF;
<> 144:ef7eb2e8f9f7 84
<> 144:ef7eb2e8f9f7 85 // Using internal reference of 1.20V
<> 144:ef7eb2e8f9f7 86
<> 144:ef7eb2e8f9f7 87 // Enable ADC power bypass the buffer
<> 144:ef7eb2e8f9f7 88 obj->adc->ctrl |= (MXC_F_ADC_CTRL_ADC_PU | MXC_F_ADC_CTRL_ADC_REFBUF_PU |
<> 144:ef7eb2e8f9f7 89 MXC_F_ADC_CTRL_ADC_CHGPUMP_PU | MXC_F_ADC_CTRL_BUF_BYPASS);
<> 144:ef7eb2e8f9f7 90
<> 144:ef7eb2e8f9f7 91 // Wait for ADC ready
<> 144:ef7eb2e8f9f7 92 while (!(obj->adc->intr & MXC_F_ADC_INTR_ADC_REF_READY_IF));
<> 144:ef7eb2e8f9f7 93
<> 144:ef7eb2e8f9f7 94 initialized = 1;
<> 144:ef7eb2e8f9f7 95 }
<> 144:ef7eb2e8f9f7 96 }
<> 144:ef7eb2e8f9f7 97
<> 144:ef7eb2e8f9f7 98 //******************************************************************************
<> 144:ef7eb2e8f9f7 99 float analogin_read(analogin_t *obj)
<> 144:ef7eb2e8f9f7 100 {
<> 144:ef7eb2e8f9f7 101 // Convert integer to float
<> 144:ef7eb2e8f9f7 102 return (((float)analogin_read_u16(obj)/(float)ADC_FULL_SCALE));
<> 144:ef7eb2e8f9f7 103 }
<> 144:ef7eb2e8f9f7 104
<> 144:ef7eb2e8f9f7 105 //******************************************************************************
<> 144:ef7eb2e8f9f7 106 uint16_t analogin_read_u16(analogin_t *obj)
<> 144:ef7eb2e8f9f7 107 {
<> 144:ef7eb2e8f9f7 108 // Set the pin to take readings from
<> 144:ef7eb2e8f9f7 109 uint32_t adc_input = PINNAME_TO_PIN(obj->adc_pin);
<> 144:ef7eb2e8f9f7 110
<> 144:ef7eb2e8f9f7 111 // Select the channel
<> 144:ef7eb2e8f9f7 112 obj->adc->ctrl &= ~MXC_F_ADC_CTRL_ADC_CHSEL;
<> 144:ef7eb2e8f9f7 113 obj->adc->ctrl |= (adc_input << MXC_F_ADC_CTRL_ADC_CHSEL_POS) & MXC_F_ADC_CTRL_ADC_CHSEL;
<> 144:ef7eb2e8f9f7 114
<> 144:ef7eb2e8f9f7 115 // We want unity gain, to get full 0-Vref range
<> 144:ef7eb2e8f9f7 116 // So, both ref and adc input scale should be enabled
<> 144:ef7eb2e8f9f7 117 obj->adc->ctrl |= MXC_F_ADC_CTRL_ADC_SCALE | MXC_F_ADC_CTRL_ADC_REFSCL;
<> 144:ef7eb2e8f9f7 118
<> 144:ef7eb2e8f9f7 119 // Not using internal buffer, disable anyway
<> 144:ef7eb2e8f9f7 120 obj->adc->ctrl &= ~MXC_F_ADC_CTRL_BUF_PU;
<> 144:ef7eb2e8f9f7 121 obj->adc->ctrl |= MXC_F_ADC_CTRL_BUF_BYPASS;
<> 144:ef7eb2e8f9f7 122
<> 144:ef7eb2e8f9f7 123 // Normal LSB justified data alignment
<> 144:ef7eb2e8f9f7 124
<> 144:ef7eb2e8f9f7 125 // Not using limits
<> 144:ef7eb2e8f9f7 126
<> 144:ef7eb2e8f9f7 127 // Clear ADC done flag (wite 1 to clr)
<> 144:ef7eb2e8f9f7 128 obj->adc->intr = (obj->adc->intr & 0xFFFF) | MXC_F_ADC_INTR_ADC_DONE_IF;
<> 144:ef7eb2e8f9f7 129
<> 144:ef7eb2e8f9f7 130 // Start the conversion
<> 144:ef7eb2e8f9f7 131 obj->adc->ctrl |= MXC_F_ADC_CTRL_CPU_ADC_START;
<> 144:ef7eb2e8f9f7 132
<> 144:ef7eb2e8f9f7 133 // Wait for ADC done
<> 144:ef7eb2e8f9f7 134 while (!(obj->adc->intr & MXC_F_ADC_INTR_ADC_DONE_IF));
<> 144:ef7eb2e8f9f7 135
<> 144:ef7eb2e8f9f7 136 // Get sample from the fifo
<> 144:ef7eb2e8f9f7 137 uint16_t sample = obj->adc->data;
<> 144:ef7eb2e8f9f7 138
<> 144:ef7eb2e8f9f7 139 // Check for overflow, hardware will report overflow as 0
<> 144:ef7eb2e8f9f7 140 if (obj->adc->status & MXC_F_ADC_STATUS_ADC_OVERFLOW) {
<> 144:ef7eb2e8f9f7 141 sample = (uint16_t)ADC_FULL_SCALE;
<> 144:ef7eb2e8f9f7 142 }
<> 144:ef7eb2e8f9f7 143
<> 144:ef7eb2e8f9f7 144 return sample;
<> 144:ef7eb2e8f9f7 145 }