From bc432b1feb906e5c2895d35bf1430fa6bf004061 Mon Sep 17 00:00:00 2001
From: px4dev <px4@purgatory.org>
Date: Mon, 31 Dec 2012 17:06:30 -0800
Subject: [PATCH] Cleanup and add support for multiple channels.
---
apps/drivers/boards/px4fmu/px4fmu_init.c | 2 -
apps/drivers/drv_adc.h | 2 -
apps/drivers/stm32/adc/adc.cpp | 112 ++++++++++++++++++-----
3 files changed, 88 insertions(+), 28 deletions(-)
diff --git a/apps/drivers/boards/px4fmu/px4fmu_init.c b/apps/drivers/boards/px4fmu/px4fmu_init.c
index 4ebc5a439e..c2aed9b546 100644
--- a/apps/drivers/boards/px4fmu/px4fmu_init.c
+++ b/apps/drivers/boards/px4fmu/px4fmu_init.c
@@ -95,8 +95,6 @@
* Protected Functions
****************************************************************************/
-extern int adc_devinit(void);
-
/****************************************************************************
* Public Functions
****************************************************************************/
diff --git a/apps/drivers/drv_adc.h b/apps/drivers/drv_adc.h
index f42350cbb5..8ec6d1233f 100644
--- a/apps/drivers/drv_adc.h
+++ b/apps/drivers/drv_adc.h
@@ -45,8 +45,6 @@
#include <stdint.h>
#include <sys/ioctl.h>
-#include <nuttx/compiler.h>
-
#define ADC_DEVICE_PATH "/dev/adc0"
/*
diff --git a/apps/drivers/stm32/adc/adc.cpp b/apps/drivers/stm32/adc/adc.cpp
index f77499706e..ed40b478a1 100644
--- a/apps/drivers/stm32/adc/adc.cpp
+++ b/apps/drivers/stm32/adc/adc.cpp
@@ -62,13 +62,13 @@
#include <stm32_gpio.h>
#include <systemlib/err.h>
-
-#define ADC_BASE STM32_ADC1_BASE
+#include <systemlib/perf_counter.h>
/*
* Register accessors.
+ * For now, no reason not to just use ADC1.
*/
-#define REG(_reg) (*(volatile uint32_t *)(_base + _reg))
+#define REG(_reg) (*(volatile uint32_t *)(STM32_ADC1_BASE + _reg))
#define rSR REG(STM32_ADC_SR_OFFSET)
#define rCR1 REG(STM32_ADC_CR1_OFFSET)
@@ -94,7 +94,7 @@
class ADC : public device::CDev
{
public:
- ADC();
+ ADC(uint32_t channels);
~ADC();
virtual int init();
@@ -107,27 +107,64 @@ protected:
virtual int close_last(struct file *filp);
private:
- static const hrt_abstime _tickrate = 10000; /* 100Hz base rate */
- static const uint32_t _base = ADC_BASE;
-
+ static const hrt_abstime _tickrate = 10000; /**< 100Hz base rate */
+
hrt_call _call;
+ perf_counter_t _sample_perf;
+
+ unsigned _channel_count;
+ adc_msg_s *_samples; /**< sample buffer */
+ /** work trampoline */
static void _tick_trampoline(void *arg);
+
+ /** worker function */
void _tick();
+ /**
+ * Sample a single channel and return the measured value.
+ *
+ * @param channel The channel to sample.
+ * @return The sampled value, or 0xffff if
+ * sampling failed.
+ */
uint16_t _sample(unsigned channel);
- uint16_t _result;
};
-ADC::ADC() :
- CDev("adc", ADC_DEVICE_PATH)
+ADC::ADC(uint32_t channels) :
+ CDev("adc", ADC_DEVICE_PATH),
+ _sample_perf(perf_alloc(PC_ELAPSED, "ADC samples")),
+ _channel_count(0),
+ _samples(nullptr)
{
_debug_enabled = true;
+
+ /* allocate the sample array */
+ for (unsigned i = 0; i < 32; i++) {
+ if (channels & (1 << i)) {
+ _channel_count++;
+ }
+ }
+ _samples = new adc_msg_s[_channel_count];
+
+ /* prefill the channel numbers in the sample array */
+ if (_samples != nullptr) {
+ unsigned index = 0;
+ for (unsigned i = 0; i < 32; i++) {
+ if (channels & (1 << i)) {
+ _samples[index].am_channel = i;
+ _samples[index].am_data = 0;
+ index++;
+ }
+ }
+ }
}
ADC::~ADC()
{
+ if (_samples != nullptr)
+ delete _samples;
}
int
@@ -158,7 +195,7 @@ ADC::init()
/* configure for a single-channel sequence */
rSQR1 = 0;
rSQR2 = 0;
- rSQR3 = 11; /* will be updated with the channel each tick */
+ rSQR3 = 0; /* will be updated with the channel each tick */
/* power-cycle the ADC and turn it on */
rCR2 &= ~ADC_CR2_ADON;
@@ -180,6 +217,8 @@ ADC::init()
return 0xffff;
}
}
+
+
debug("init done");
/* create the device node */
@@ -195,18 +234,26 @@ ADC::ioctl(file *filp, int cmd, unsigned long arg)
ssize_t
ADC::read(file *filp, char *buffer, size_t len)
{
- if (len > sizeof(_result))
- len = sizeof(_result);
+ const size_t maxsize = sizeof(adc_msg_s) * _channel_count;
-// _result = _sample(11);
+ if (len > maxsize)
+ len = maxsize;
+
+ /* block interrupts while copying samples to avoid racing with an update */
+ irqstate_t flags = irqsave();
+ memcpy(buffer, _samples, len);
+ irqrestore(flags);
- memcpy(buffer, &_result, len);
return len;
}
int
ADC::open_first(struct file *filp)
{
+ /* get fresh data */
+ _tick();
+
+ /* and schedule regular updates */
hrt_call_every(&_call, _tickrate, _tickrate, _tick_trampoline, this);
return 0;
@@ -228,12 +275,20 @@ ADC::_tick_trampoline(void *arg)
void
ADC::_tick()
{
- _result = _sample(11);
+ /* scan the channel set and sample each */
+ for (unsigned i = 0; i < _channel_count; i++)
+ _samples[i].am_data = _sample(_samples[i].am_channel);
}
uint16_t
ADC::_sample(unsigned channel)
{
+ perf_begin(_sample_perf);
+
+ /* clear any previous EOC */
+ if (rSR & ADC_SR_EOC)
+ rSR &= ~ADC_SR_EOC;
+
/* run a single conversion right now - should take about 60 cycles (a few microseconds) max */
rSQR3 = channel;
rCR2 |= ADC_CR2_SWSTART;
@@ -252,6 +307,7 @@ ADC::_sample(unsigned channel)
/* read the result and clear EOC */
uint16_t result = rDR;
+ perf_end(_sample_perf);
return result;
}
@@ -267,18 +323,25 @@ ADC *g_adc;
void
test(void)
{
- int fd;
- fd = open(ADC_DEVICE_PATH, O_RDONLY);
+ int fd = open(ADC_DEVICE_PATH, O_RDONLY);
if (fd < 0)
err(1, "can't open ADC device");
- uint16_t value;
-
for (unsigned i = 0; i < 50; i++) {
- if (read(fd, &value, sizeof(value)) != sizeof(value))
- errx(1, "short read");
- printf(" %d\n", value);
+ adc_msg_s data[8];
+ ssize_t count = read(fd, data, sizeof(data));
+
+ if (count < 0)
+ errx(1, "read error");
+
+ unsigned channels = count / sizeof(data[0]);
+
+ for (unsigned j = 0; j < channels; j++) {
+ printf ("%d: %u ", data[j].am_channel, data[j].am_data);
+ }
+
+ printf("\n");
usleep(500000);
}
@@ -290,7 +353,8 @@ int
adc_main(int argc, char *argv[])
{
if (g_adc == nullptr) {
- g_adc = new ADC;
+ /* XXX this hardcodes the minimum channel set for PX4FMU - should be configurable */
+ g_adc = new ADC((1 << 10) | (1 << 11));
if (g_adc == nullptr)
errx(1, "couldn't allocate the ADC driver");
--
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