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