| /* |
| * Copyright 2011-2012 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/iio/iio.h> |
| #include <linux/iio/buffer.h> |
| #include <linux/iio/trigger_consumer.h> |
| #include <linux/iio/triggered_buffer.h> |
| |
| #include "ad7606.h" |
| |
| /** |
| * 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 ad7606_state *st = iio_priv(pf->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); |
| __u8 *buf; |
| int ret; |
| |
| buf = kzalloc(indio_dev->scan_bytes, GFP_KERNEL); |
| if (!buf) |
| return; |
| |
| if (gpio_is_valid(st->pdata->gpio_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; |
| } |
| |
| iio_push_to_buffers_with_timestamp(indio_dev, buf, |
| iio_get_time_ns(indio_dev)); |
| done: |
| gpio_set_value(st->pdata->gpio_convst, 0); |
| iio_trigger_notify_done(indio_dev->trig); |
| kfree(buf); |
| } |
| |
| int ad7606_register_ring_funcs_and_init(struct iio_dev *indio_dev) |
| { |
| struct ad7606_state *st = iio_priv(indio_dev); |
| |
| INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring); |
| |
| return iio_triggered_buffer_setup(indio_dev, |
| &ad7606_trigger_handler_th_bh, &ad7606_trigger_handler_th_bh, |
| NULL); |
| } |
| |
| void ad7606_ring_cleanup(struct iio_dev *indio_dev) |
| { |
| iio_triggered_buffer_cleanup(indio_dev); |
| } |