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/*******************************************************************************
* Copyright (C) 2015 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 "analogin_api.h"
#include "clkman_regs.h"
#include "pwrman_regs.h"
#include "afe_regs.h"
#include "PeripheralPins.h"
#define PGA_TRK_CNT 0x1F
#define ADC_ACT_CNT 0x1
#define ADC_PGA_CNT 0x1
#define ADC_ACQ_CNT 0x1
#define ADC_SLP_CNT 0x1
//******************************************************************************
void analogin_init(analogin_t *obj, PinName pin)
{
// Make sure pin is an analog pin we can use for ADC
MBED_ASSERT((ADCName)pinmap_peripheral(pin, PinMap_ADC) != (ADCName)NC);
// Set the object pointer
obj->adc = MXC_ADC;
obj->adccfg = MXC_ADCCFG;
obj->adc_fifo = MXC_ADC_FIFO;
obj->adc_pin = pin;
// Set the ADC clock to the system clock frequency
MXC_SET_FIELD(&MXC_CLKMAN->clk_ctrl, MXC_F_CLKMAN_CLK_CTRL_ADC_SOURCE_SELECT,
(MXC_F_CLKMAN_CLK_CTRL_ADC_GATE_N | (MXC_E_CLKMAN_ADC_SOURCE_SELECT_SYSTEM <<
MXC_F_CLKMAN_CLK_CTRL_ADC_SOURCE_SELECT_POS)));
// Enable AFE power
MXC_PWRMAN->pwr_rst_ctrl |= MXC_F_PWRMAN_PWR_RST_CTRL_AFE_POWERED;
// Setup and hold window
MXC_SET_FIELD(&obj->adc->tg_ctrl0, MXC_F_ADC_TG_CTRL0_PGA_TRK_CNT, PGA_TRK_CNT);
// Setup sampling count and timing
MXC_SET_FIELD(&obj->adc->tg_ctrl1, (MXC_F_ADC_TG_CTRL1_PGA_ACQ_CNT |
MXC_F_ADC_TG_CTRL1_ADC_ACQ_CNT | MXC_F_ADC_TG_CTRL1_ADC_SLP_CNT),
((ADC_PGA_CNT << MXC_F_ADC_TG_CTRL1_PGA_ACQ_CNT_POS) |
(ADC_ACQ_CNT << MXC_F_ADC_TG_CTRL1_ADC_ACQ_CNT_POS) |
(ADC_SLP_CNT << MXC_F_ADC_TG_CTRL1_ADC_SLP_CNT_POS) |
(MXC_F_ADC_TG_CTRL1_ADC_BRST_CNT)));
}
//******************************************************************************
float analogin_read(analogin_t *obj)
{
// Convert integer to float
return (((float)analogin_read_u16(obj)/(float)0xFFFF));
}
//******************************************************************************
uint16_t analogin_read_u16(analogin_t *obj)
{
// Set the pin to take readings from
unsigned mux_pos;
unsigned diff = 0;
if(obj->adc_pin >> PORT_SHIFT == 0xB) {
mux_pos = (obj->adc_pin & 0xF) + 8;
} else {
mux_pos = (obj->adc_pin & 0xF);
}
if(obj->adc_pin >> PORT_SHIFT == 0xC) {
diff = 1;
mux_pos = (obj->adc_pin & 0xF) + 8;
}
// Reset the ADC
obj->adc->ctrl0 |= MXC_F_ADC_CTRL0_CPU_ADC_RST;
// Enable the ADC
obj->adc->ctrl0 |= MXC_F_ADC_CTRL0_CPU_ADC_EN;
// Setup the ADC clock
MXC_SET_FIELD(&obj->adc->ctrl0, (MXC_F_ADC_CTRL0_ADC_MODE | MXC_F_ADC_CTRL0_AVG_MODE |
MXC_F_ADC_CTRL0_ADC_CLK_MODE | MXC_F_ADC_CTRL0_ADC_BI_POL),
((MXC_E_ADC_MODE_SMPLCNT_FULL_RATE << MXC_F_ADC_CTRL0_ADC_MODE_POS) |
(MXC_E_ADC_AVG_MODE_FILTER_OUTPUT << MXC_F_ADC_CTRL0_AVG_MODE_POS) |
(0x2 << MXC_F_ADC_CTRL0_ADC_CLK_MODE_POS) |
MXC_F_ADC_CTRL0_ADC_CLK_EN));
// Setup the input multiplexor
MXC_SET_FIELD(&obj->adc->pga_ctrl, (MXC_F_ADC_PGA_CTRL_MUX_CH_SEL |
MXC_F_ADC_PGA_CTRL_MUX_DIFF | MXC_F_ADC_PGA_CTRL_PGA_GAIN),
((mux_pos << MXC_F_ADC_PGA_CTRL_MUX_CH_SEL_POS) |
(diff << MXC_F_ADC_PGA_CTRL_MUX_DIFF_POS)));
// Setup voltage reference
MXC_SET_FIELD(&MXC_AFE->ctrl1, MXC_F_AFE_CTRL1_REF_ADC_VOLT_SEL,
(MXC_F_AFE_CTRL1_REF_ADC_POWERUP | MXC_F_AFE_CTRL1_REF_BLK_POWERUP |
(MXC_E_AFE_REF_VOLT_SEL_1500 << MXC_F_AFE_CTRL1_REF_ADC_VOLT_SEL_POS)));
// Clear the done bit
obj->adc->intr = MXC_F_ADC_INTR_DONE_IF;
// Take one sample
obj->adc->tg_ctrl0 |= (1 << MXC_F_ADC_TG_CTRL0_ADC_SMPL_CNT_POS);
// Set the start bit to take the sample
obj->adc->ctrl0 |= MXC_F_ADC_CTRL0_CPU_ADC_START;
// Wait for the conversion to complete
while(!(obj->adc->intr & MXC_F_ADC_INTR_DONE_IF)) {}
// Get sample from the fifo
uint16_t sample = (uint16_t)(obj->adc->out & 0xFFFF);
// Disable ADC
obj->adc->ctrl0 &= ~MXC_F_ADC_CTRL0_CPU_ADC_EN;
return (sample - 1);
}
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