165 lines
4.1 KiB
C
165 lines
4.1 KiB
C
/*
|
|
* AD7298 SPI ADC driver
|
|
*
|
|
* Copyright 2011 Analog Devices Inc.
|
|
*
|
|
* Licensed under the GPL-2.
|
|
*/
|
|
|
|
#include <linux/interrupt.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/spi/spi.h>
|
|
|
|
#include "../iio.h"
|
|
#include "../buffer.h"
|
|
#include "../ring_sw.h"
|
|
#include "../trigger_consumer.h"
|
|
|
|
#include "ad7298.h"
|
|
|
|
/**
|
|
* ad7298_ring_preenable() setup the parameters of the ring before enabling
|
|
*
|
|
* The complex nature of the setting of the number of bytes per datum is due
|
|
* to this driver currently ensuring that the timestamp is stored at an 8
|
|
* byte boundary.
|
|
**/
|
|
static int ad7298_ring_preenable(struct iio_dev *indio_dev)
|
|
{
|
|
struct ad7298_state *st = iio_priv(indio_dev);
|
|
struct iio_buffer *ring = indio_dev->buffer;
|
|
size_t d_size;
|
|
int i, m;
|
|
unsigned short command;
|
|
int scan_count = bitmap_weight(indio_dev->active_scan_mask,
|
|
indio_dev->masklength);
|
|
d_size = scan_count * (AD7298_STORAGE_BITS / 8);
|
|
|
|
if (ring->scan_timestamp) {
|
|
d_size += sizeof(s64);
|
|
|
|
if (d_size % sizeof(s64))
|
|
d_size += sizeof(s64) - (d_size % sizeof(s64));
|
|
}
|
|
|
|
if (ring->access->set_bytes_per_datum)
|
|
ring->access->set_bytes_per_datum(ring, d_size);
|
|
|
|
st->d_size = d_size;
|
|
|
|
command = AD7298_WRITE | st->ext_ref;
|
|
|
|
for (i = 0, m = AD7298_CH(0); i < AD7298_MAX_CHAN; i++, m >>= 1)
|
|
if (test_bit(i, indio_dev->active_scan_mask))
|
|
command |= m;
|
|
|
|
st->tx_buf[0] = cpu_to_be16(command);
|
|
|
|
/* build spi ring message */
|
|
st->ring_xfer[0].tx_buf = &st->tx_buf[0];
|
|
st->ring_xfer[0].len = 2;
|
|
st->ring_xfer[0].cs_change = 1;
|
|
st->ring_xfer[1].tx_buf = &st->tx_buf[1];
|
|
st->ring_xfer[1].len = 2;
|
|
st->ring_xfer[1].cs_change = 1;
|
|
|
|
spi_message_init(&st->ring_msg);
|
|
spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
|
|
spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
|
|
|
|
for (i = 0; i < scan_count; i++) {
|
|
st->ring_xfer[i + 2].rx_buf = &st->rx_buf[i];
|
|
st->ring_xfer[i + 2].len = 2;
|
|
st->ring_xfer[i + 2].cs_change = 1;
|
|
spi_message_add_tail(&st->ring_xfer[i + 2], &st->ring_msg);
|
|
}
|
|
/* make sure last transfer cs_change is not set */
|
|
st->ring_xfer[i + 1].cs_change = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ad7298_trigger_handler() bh of trigger launched polling to ring buffer
|
|
*
|
|
* Currently there is no option in this driver to disable the saving of
|
|
* timestamps within the ring.
|
|
**/
|
|
static irqreturn_t ad7298_trigger_handler(int irq, void *p)
|
|
{
|
|
struct iio_poll_func *pf = p;
|
|
struct iio_dev *indio_dev = pf->indio_dev;
|
|
struct ad7298_state *st = iio_priv(indio_dev);
|
|
struct iio_buffer *ring = indio_dev->buffer;
|
|
s64 time_ns;
|
|
__u16 buf[16];
|
|
int b_sent, i;
|
|
|
|
b_sent = spi_sync(st->spi, &st->ring_msg);
|
|
if (b_sent)
|
|
return b_sent;
|
|
|
|
if (ring->scan_timestamp) {
|
|
time_ns = iio_get_time_ns();
|
|
memcpy((u8 *)buf + st->d_size - sizeof(s64),
|
|
&time_ns, sizeof(time_ns));
|
|
}
|
|
|
|
for (i = 0; i < bitmap_weight(indio_dev->active_scan_mask,
|
|
indio_dev->masklength); i++)
|
|
buf[i] = be16_to_cpu(st->rx_buf[i]);
|
|
|
|
indio_dev->buffer->access->store_to(ring, (u8 *)buf, time_ns);
|
|
iio_trigger_notify_done(indio_dev->trig);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static const struct iio_buffer_setup_ops ad7298_ring_setup_ops = {
|
|
.preenable = &ad7298_ring_preenable,
|
|
.postenable = &iio_triggered_buffer_postenable,
|
|
.predisable = &iio_triggered_buffer_predisable,
|
|
};
|
|
|
|
int ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev)
|
|
{
|
|
int ret;
|
|
|
|
indio_dev->buffer = iio_sw_rb_allocate(indio_dev);
|
|
if (!indio_dev->buffer) {
|
|
ret = -ENOMEM;
|
|
goto error_ret;
|
|
}
|
|
indio_dev->pollfunc = iio_alloc_pollfunc(NULL,
|
|
&ad7298_trigger_handler,
|
|
IRQF_ONESHOT,
|
|
indio_dev,
|
|
"ad7298_consumer%d",
|
|
indio_dev->id);
|
|
|
|
if (indio_dev->pollfunc == NULL) {
|
|
ret = -ENOMEM;
|
|
goto error_deallocate_sw_rb;
|
|
}
|
|
|
|
/* Ring buffer functions - here trigger setup related */
|
|
indio_dev->setup_ops = &ad7298_ring_setup_ops;
|
|
indio_dev->buffer->scan_timestamp = true;
|
|
|
|
/* Flag that polled ring buffering is possible */
|
|
indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
|
|
return 0;
|
|
|
|
error_deallocate_sw_rb:
|
|
iio_sw_rb_free(indio_dev->buffer);
|
|
error_ret:
|
|
return ret;
|
|
}
|
|
|
|
void ad7298_ring_cleanup(struct iio_dev *indio_dev)
|
|
{
|
|
iio_dealloc_pollfunc(indio_dev->pollfunc);
|
|
iio_sw_rb_free(indio_dev->buffer);
|
|
}
|