/*
* adc-mkl27z.c - ADC driver for MKL27Z
* In this ADC driver, there are NeuG specific parts.
* It only records lower 8-bit of 16-bit data.
* You need to modify to use this as generic ADC driver.
*
* Copyright (C) 2016 Flying Stone Technology
* Author: NIIBE Yutaka <gniibe@fsij.org>
*
* This file is a part of Chopstx, a thread library for embedded.
*
* Chopstx is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Chopstx is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As additional permission under GNU GPL version 3 section 7, you may
* distribute non-source form of the Program without the copy of the
* GNU GPL normally required by section 4, provided you inform the
* receipents of GNU GPL by a written offer.
*
*/
#include <stdint.h>
#include <stdlib.h>
#include <chopstx.h>
#include <mcu/mkl27z.h>
struct DMAMUX {
volatile uint32_t CHCFG0;
volatile uint32_t CHCFG1;
volatile uint32_t CHCFG2;
volatile uint32_t CHCFG3;
};
static struct DMAMUX *const DMAMUX = (struct DMAMUX *)0x40021000;
#define INTR_REQ_DMA0 0
struct DMA {
volatile uint32_t SAR;
volatile uint32_t DAR;
volatile uint32_t DSR_BCR;
volatile uint32_t DCR;
};
static struct DMA *const DMA0 = (struct DMA *)0x40008100;
static struct DMA *const DMA1 = (struct DMA *)0x40008110;
/* We don't use ADC interrupt. Just for reference. */
#define INTR_REQ_ADC 15
struct ADC {
volatile uint32_t SC1[2];/* Status and Control Registers 1 */
volatile uint32_t CFG1; /* Configuration Register 1 */
volatile uint32_t CFG2; /* Configuration Register 2 */
volatile uint32_t R[2]; /* Data Result Register */
/* Compare Value Registers 1, 2 */
volatile uint32_t CV1;
volatile uint32_t CV2;
volatile uint32_t SC2; /* Status and Control Register 2 */
volatile uint32_t SC3; /* Status and Control Register 3 */
volatile uint32_t OFS; /* Offset Correction Register */
volatile uint32_t PG; /* Plus-Side Gain Register */
volatile uint32_t MG; /* Minus-Side Gain Register */
/* Plus-Side General Calibration Value Registers */
volatile uint32_t CLPD;
volatile uint32_t CLPS;
volatile uint32_t CLP4;
volatile uint32_t CLP3;
volatile uint32_t CLP2;
volatile uint32_t CLP1;
volatile uint32_t CLP0;
uint32_t rsvd0;
/* Minus-Side General Calibration Value Registers */
volatile uint32_t CLMD;
volatile uint32_t CLMS;
volatile uint32_t CLM4;
volatile uint32_t CLM3;
volatile uint32_t CLM2;
volatile uint32_t CLM1;
volatile uint32_t CLM0;
};
static struct ADC *const ADC0 = (struct ADC *)0x4003B000;
/* SC1 */
#define ADC_SC1_DIFF (1 << 5)
#define ADC_SC1_AIEN (1 << 6)
#define ADC_SC1_COCO (1 << 7)
#define ADC_SC1_TEMPSENSOR 26
#define ADC_SC1_BANDGAP 27
#define ADC_SC1_ADCSTOP 31
/* CFG1 */
#define ADC_CLOCK_SOURCE_ASYNCH (3 << 0)
#define ADC_MODE_16BIT (3 << 2)
#define ADC_ADLSMP_SHORT (0 << 4)
#define ADC_ADLSMP_LONG (1 << 4)
#define ADC_ADIV_1 (0 << 5)
#define ADC_ADIV_8 (3 << 5)
#define ADC_ADLPC_NORMAL (0 << 7)
#define ADC_ADLPC_LOWPOWER (1 << 7)
/**/
#define ADC_CLOCK_SOURCE ADC_CLOCK_SOURCE_ASYNCH
#define ADC_MODE ADC_MODE_16BIT
#define ADC_ADLSMP ADC_ADLSMP_SHORT
#define ADC_ADIV ADC_ADIV_1
#define ADC_ADLPC ADC_ADLPC_LOWPOWER
/* CFG2 */
#define ADC_ADLSTS_DEFAULT 0 /* 24 cycles if CFG1.ADLSMP=1, 4 if not. */
#define ADC_ADHSC_NORMAL (0 << 2)
#define ADC_ADHSC_HIGHSPEED (1 << 2)
#define ADC_ADACK_DISABLE (0 << 3)
#define ADC_ADACK_ENABLE (1 << 3)
#define ADC_MUXSEL_A (0 << 4)
#define ADC_MUXSEL_B (1 << 4)
/**/
#define ADC_ADLSTS ADC_ADLSTS_DEFAULT
#define ADC_ADHSC ADC_ADHSC_NORMAL
#define ADC_ADACKEN ADC_ADACK_ENABLE
#define ADC_MUXSEL ADC_MUXSEL_A
/* SC2 */
#define ADC_SC2_REFSEL_DEFAULT 1 /* Internal Voltage Reference??? */
#define ADC_SC2_DMAEN (1 << 2)
#define ADC_SC2_ACREN (1 << 3)
#define ADC_SC2_ACFGT (1 << 4)
#define ADC_SC2_ACFE (1 << 5)
#define ADC_SC2_ADTRG (1 << 6) /* For hardware trigger */
/* SC3 */
#define ADC_SC3_AVGS11 0x03
#define ADC_SC3_AVGE (1 << 2)
#define ADC_SC3_ADCO (1 << 3)
#define ADC_SC3_CALF (1 << 6)
#define ADC_SC3_CAL (1 << 7)
#define ADC_DMA_SLOT_NUM 40
/*
* Buffer to save ADC data.
*/
uint32_t adc_buf[64];
static const uint32_t adc0_sc1_setting = ADC_SC1_TEMPSENSOR;
static chopstx_intr_t adc_intr;
struct adc_internal {
uint32_t buf[64];
uint8_t *p;
int phase : 8;
int count : 8;
};
struct adc_internal adc;
/*
* Initialize ADC module, do calibration.
*
* This is called by MAIN, only once, hopefully before creating any
* other threads (to be accurate).
*
* We configure ADC0 to kick DMA0, configure DMA0 to kick DMA1.
* DMA0 records output of ADC0 to the ADC.BUF.
* DMA1 kicks ADC0 again to get another value.
*
* ADC0 --[finish conversion]--> DMA0 --[Link channel 1]--> DMA1
*/
int
adc_init (void)
{
uint32_t v;
/* Enable ADC0 and DMAMUX clock. */
SIM->SCGC6 |= (1 << 27) | (1 << 1);
/* Enable DMA clock. */
SIM->SCGC7 |= (1 << 8);
/* ADC0 setting for calibration. */
ADC0->CFG1 = ADC_CLOCK_SOURCE | ADC_MODE | ADC_ADLSMP | ADC_ADIV | ADC_ADLPC;
ADC0->CFG2 = ADC_ADLSTS | ADC_ADHSC | ADC_ADACKEN | ADC_MUXSEL;
ADC0->SC2 = ADC_SC2_REFSEL_DEFAULT;
ADC0->SC3 = ADC_SC3_CAL | ADC_SC3_CALF | ADC_SC3_AVGE | ADC_SC3_AVGS11;
/* Wait ADC completion */
while ((ADC0->SC1[0] & ADC_SC1_COCO) == 0)
if ((ADC0->SC3 & ADC_SC3_CALF) != 0)
/* Calibration failure */
return -1;
if ((ADC0->SC3 & ADC_SC3_CALF) != 0)
/* Calibration failure */
return -1;
/* Configure PG by the calibration values. */
v = ADC0->CLP0 + ADC0->CLP1 + ADC0->CLP2 + ADC0->CLP3 + ADC0->CLP4 + ADC0->CLPS;
ADC0->PG = 0x8000 | (v >> 1);
/* Configure MG by the calibration values. */
v = ADC0->CLM0 + ADC0->CLM1 + ADC0->CLM2 + ADC0->CLM3 + ADC0->CLM4 + ADC0->CLMS;
ADC0->MG = 0x8000 | (v >> 1);
ADC0->SC1[0] = ADC_SC1_ADCSTOP;
/* DMAMUX setting. */
DMAMUX->CHCFG0 = (1 << 7) | ADC_DMA_SLOT_NUM;
/* DMA0 initial setting. */
DMA0->SAR = (uint32_t)&ADC0->R[0];
/* DMA1 initial setting. */
DMA1->SAR = (uint32_t)&adc0_sc1_setting;
DMA1->DAR = (uint32_t)&ADC0->SC1[0];
chopstx_claim_irq (&adc_intr, INTR_REQ_DMA0);
return 0;
}
/*
* Start using ADC.
*/
void
adc_start (void)
{
ADC0->CFG1 = ADC_CLOCK_SOURCE | ADC_MODE | ADC_ADLSMP | ADC_ADIV | ADC_ADLPC;
ADC0->CFG2 = ADC_ADLSTS | ADC_ADHSC | ADC_ADACKEN | ADC_MUXSEL;
ADC0->SC2 = ADC_SC2_REFSEL_DEFAULT | ADC_SC2_DMAEN;
ADC0->SC3 = 0;
}
/*
* Kick getting data for COUNT times.
* Data will be saved in ADC_BUF starting at OFFSET.
*/
static void
adc_start_conversion_internal (int count)
{
/* DMA0 setting. */
DMA0->DAR = (uint32_t)&adc.buf[0];
DMA0->DSR_BCR = 4 * count;
DMA0->DCR = (1 << 31) | (1 << 30) | (1 << 29) | (0 << 20) | (1 << 19)
| (0 << 17) | (1 << 7) | (2 << 4) | (1 << 2);
/* Kick DMA1. */
DMA1->DSR_BCR = 4 * count;
DMA1->DCR = (1 << 30) | (1 << 29) | (0 << 19) | (0 << 17) | (1 << 16) | (1 << 7);
}
/*
* Kick getting data for COUNT times.
* Data will be saved in ADC_BUF starting at OFFSET.
*/
void
adc_start_conversion (int offset, int count)
{
adc.p = (uint8_t *)&adc_buf[offset];
adc.phase = 0;
adc.count = count;
adc_start_conversion_internal (count);
}
static void
adc_stop_conversion (void)
{
ADC0->SC1[0] = ADC_SC1_ADCSTOP;
}
/*
* Stop using ADC.
*/
void
adc_stop (void)
{
SIM->SCGC6 &= ~(1 << 27);
}
/*
* Return 0 on success.
* Return 1 on error.
*/
int
adc_wait_completion (void)
{
struct chx_poll_head *pd_array[1] = { (struct chx_poll_head *)&adc_intr };
int i;
while (1)
{
/* Wait DMA completion */
chopstx_poll (NULL, 1, pd_array);
DMA0->DSR_BCR = (1 << 24);
DMA1->DSR_BCR = (1 << 24);
adc_stop_conversion ();
for (i = 0; i < adc.count; i++)
*adc.p++ = (uint8_t)adc.buf[i];
if (++adc.phase >= 4)
break;
adc_start_conversion_internal (adc.count);
}
return 0;
}