Files
OpenCellular/chip/mec1322/adc.c
Vijay Hiremath e7bebf7c80 ADC: Add common priority for the ADC init
Added common priority for the ADC init to ensure board level
priority is defined for the ADC pre init.

BUG=none
TEST=make buildall -j
BRANCH=none

Change-Id: Id1649df6a68ab53bd110e58a0722bd4c70cbffc5
Signed-off-by: Vijay Hiremath <vijay.p.hiremath@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/286040
Reviewed-by: Shawn N <shawnn@chromium.org>
2015-07-16 05:15:22 +00:00

108 lines
2.3 KiB
C

/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "adc.h"
#include "adc_chip.h"
#include "common.h"
#include "console.h"
#include "hooks.h"
#include "registers.h"
#include "task.h"
#include "timer.h"
#include "util.h"
/*
* Conversion on a single channel takes less than 12 ms. Set timeout to
* 15 ms so that we have a 3-ms margin.
*/
#define ADC_SINGLE_READ_TIME 15000
struct mutex adc_lock;
static task_id_t task_waiting;
static int start_single_and_wait(int timeout)
{
int event;
task_waiting = task_get_current();
/* Start conversion */
MEC1322_ADC_CTRL |= 1 << 1;
/* Wait for interrupt */
event = task_wait_event(timeout);
task_waiting = TASK_ID_INVALID;
return event != TASK_EVENT_TIMER;
}
int adc_read_channel(enum adc_channel ch)
{
const struct adc_t *adc = adc_channels + ch;
int value;
mutex_lock(&adc_lock);
MEC1322_ADC_SINGLE = 1 << adc->channel;
if (start_single_and_wait(ADC_SINGLE_READ_TIME))
value = MEC1322_ADC_READ(adc->channel) * adc->factor_mul /
adc->factor_div + adc->shift;
else
value = ADC_READ_ERROR;
mutex_unlock(&adc_lock);
return value;
}
int adc_read_all_channels(int *data)
{
int i;
int ret = EC_SUCCESS;
const struct adc_t *adc;
mutex_lock(&adc_lock);
MEC1322_ADC_SINGLE = 0;
for (i = 0; i < ADC_CH_COUNT; ++i)
MEC1322_ADC_SINGLE |= 1 << adc_channels[i].channel;
if (!start_single_and_wait(ADC_SINGLE_READ_TIME * ADC_CH_COUNT))
goto exit_all_channels;
for (i = 0; i < ADC_CH_COUNT; ++i) {
adc = adc_channels + i;
data[i] = MEC1322_ADC_READ(adc->channel) * adc->factor_mul /
adc->factor_div + adc->shift;
}
exit_all_channels:
mutex_unlock(&adc_lock);
return ret;
}
static void adc_init(void)
{
/* Activate ADC module */
MEC1322_ADC_CTRL |= 1 << 0;
/* Enable interrupt */
task_waiting = TASK_ID_INVALID;
MEC1322_INT_ENABLE(17) |= 1 << 10;
MEC1322_INT_BLK_EN |= 1 << 17;
task_enable_irq(MEC1322_IRQ_ADC_SNGL);
}
DECLARE_HOOK(HOOK_INIT, adc_init, HOOK_PRIO_INIT_ADC);
void adc_interrupt(void)
{
/* Clear interrupt status bit */
MEC1322_ADC_CTRL |= 1 << 7;
if (task_waiting != TASK_ID_INVALID)
task_wake(task_waiting);
}
DECLARE_IRQ(MEC1322_IRQ_ADC_SNGL, adc_interrupt, 2);