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/*
* Copyright 2011 Analog Devices Inc.
*
* Licensed under the GPL-2.
*
*/
#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include "../iio.h"
#include "../ring_generic.h"
#include "../ring_sw.h"
#include "../trigger.h"
#include "../sysfs.h"
#include "ad7606.h"
int ad7606_scan_from_ring(struct iio_dev *indio_dev, unsigned ch)
{
struct iio_ring_buffer *ring = indio_dev->ring;
int ret;
u16 *ring_data;
ring_data = kmalloc(ring->access->get_bytes_per_datum(ring),
GFP_KERNEL);
if (ring_data == NULL) {
ret = -ENOMEM;
goto error_ret;
}
ret = ring->access->read_last(ring, (u8 *) ring_data);
if (ret)
goto error_free_ring_data;
ret = ring_data[ch];
error_free_ring_data:
kfree(ring_data);
error_ret:
return ret;
}
/**
* ad7606_ring_preenable() setup the parameters of the ring before enabling
*
* The complex nature of the setting of the nuber of bytes per datum is due
* to this driver currently ensuring that the timestamp is stored at an 8
* byte boundary.
**/
static int ad7606_ring_preenable(struct iio_dev *indio_dev)
{
struct ad7606_state *st = iio_priv(indio_dev);
struct iio_ring_buffer *ring = indio_dev->ring;
size_t d_size;
d_size = st->chip_info->num_channels *
st->chip_info->channels[0].scan_type.storagebits / 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;
return 0;
}
/**
* ad7606_trigger_handler_th() th/bh of trigger launched polling to ring buffer
*
**/
static irqreturn_t ad7606_trigger_handler_th_bh(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->private_data;
struct ad7606_state *st = iio_priv(indio_dev);
gpio_set_value(st->pdata->gpio_convst, 1);
return IRQ_HANDLED;
}
/**
* ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
* @work_s: the work struct through which this was scheduled
*
* Currently there is no option in this driver to disable the saving of
* timestamps within the ring.
* I think the one copy of this at a time was to avoid problems if the
* trigger was set far too high and the reads then locked up the computer.
**/
static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
{
struct ad7606_state *st = container_of(work_s, struct ad7606_state,
poll_work);
struct iio_dev *indio_dev = iio_priv_to_dev(st);
struct iio_ring_buffer *ring = indio_dev->ring;
s64 time_ns;
__u8 *buf;
int ret;
buf = kzalloc(st->d_size, GFP_KERNEL);
if (buf == NULL)
return;
if (st->have_frstdata) {
ret = st->bops->read_block(st->dev, 1, buf);
if (ret)
goto done;
if (!gpio_get_value(st->pdata->gpio_frstdata)) {
/* This should never happen. However
* some signal glitch caused by bad PCB desgin or
* electrostatic discharge, could cause an extra read
* or clock. This allows recovery.
*/
ad7606_reset(st);
goto done;
}
ret = st->bops->read_block(st->dev,
st->chip_info->num_channels - 1, buf + 2);
if (ret)
goto done;
} else {
ret = st->bops->read_block(st->dev,
st->chip_info->num_channels, buf);
if (ret)
goto done;
}
time_ns = iio_get_time_ns();
if (ring->scan_timestamp)
memcpy(buf + st->d_size - sizeof(s64),
&time_ns, sizeof(time_ns));
ring->access->store_to(indio_dev->ring, buf, time_ns);
done:
gpio_set_value(st->pdata->gpio_convst, 0);
iio_trigger_notify_done(indio_dev->trig);
kfree(buf);
}
static const struct iio_ring_setup_ops ad7606_ring_setup_ops = {
.preenable = &ad7606_ring_preenable,
.postenable = &iio_triggered_ring_postenable,
.predisable = &iio_triggered_ring_predisable,
};
int ad7606_register_ring_funcs_and_init(struct iio_dev *indio_dev)
{
struct ad7606_state *st = iio_priv(indio_dev);
int ret;
indio_dev->ring = iio_sw_rb_allocate(indio_dev);
if (!indio_dev->ring) {
ret = -ENOMEM;
goto error_ret;
}
/* Effectively select the ring buffer implementation */
indio_dev->ring->access = &ring_sw_access_funcs;
indio_dev->pollfunc = iio_alloc_pollfunc(&ad7606_trigger_handler_th_bh,
&ad7606_trigger_handler_th_bh,
0,
indio_dev,
"%s_consumer%d",
indio_dev->name,
indio_dev->id);
if (indio_dev->pollfunc == NULL) {
ret = -ENOMEM;
goto error_deallocate_sw_rb;
}
/* Ring buffer functions - here trigger setup related */
indio_dev->ring->setup_ops = &ad7606_ring_setup_ops;
indio_dev->ring->scan_timestamp = true ;
INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);
/* Flag that polled ring buffering is possible */
indio_dev->modes |= INDIO_RING_TRIGGERED;
return 0;
error_deallocate_sw_rb:
iio_sw_rb_free(indio_dev->ring);
error_ret:
return ret;
}
void ad7606_ring_cleanup(struct iio_dev *indio_dev)
{
if (indio_dev->trig) {
iio_put_trigger(indio_dev->trig);
iio_trigger_dettach_poll_func(indio_dev->trig,
indio_dev->pollfunc);
}
iio_dealloc_pollfunc(indio_dev->pollfunc);
iio_sw_rb_free(indio_dev->ring);
}
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