| /* |
| * Copyright 2010-2012 Analog Devices Inc. |
| * Copyright (C) 2008 Jonathan Cameron |
| * |
| * Licensed under the GPL-2. |
| * |
| * ad7887_ring.c |
| */ |
| |
| #include <linux/interrupt.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/spi/spi.h> |
| |
| #include <linux/iio/iio.h> |
| #include <linux/iio/buffer.h> |
| #include <linux/iio/trigger_consumer.h> |
| #include <linux/iio/triggered_buffer.h> |
| |
| #include "ad7887.h" |
| |
| /** |
| * ad7887_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 ad7887_ring_preenable(struct iio_dev *indio_dev) |
| { |
| struct ad7887_state *st = iio_priv(indio_dev); |
| int ret; |
| |
| ret = iio_sw_buffer_preenable(indio_dev); |
| if (ret < 0) |
| return ret; |
| |
| /* We know this is a single long so can 'cheat' */ |
| switch (*indio_dev->active_scan_mask) { |
| case (1 << 0): |
| st->ring_msg = &st->msg[AD7887_CH0]; |
| break; |
| case (1 << 1): |
| st->ring_msg = &st->msg[AD7887_CH1]; |
| /* Dummy read: push CH1 setting down to hardware */ |
| spi_sync(st->spi, st->ring_msg); |
| break; |
| case ((1 << 1) | (1 << 0)): |
| st->ring_msg = &st->msg[AD7887_CH0_CH1]; |
| break; |
| } |
| |
| return 0; |
| } |
| |
| static int ad7887_ring_postdisable(struct iio_dev *indio_dev) |
| { |
| struct ad7887_state *st = iio_priv(indio_dev); |
| |
| /* dummy read: restore default CH0 settin */ |
| return spi_sync(st->spi, &st->msg[AD7887_CH0]); |
| } |
| |
| /** |
| * ad7887_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 ad7887_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *indio_dev = pf->indio_dev; |
| struct ad7887_state *st = iio_priv(indio_dev); |
| s64 time_ns; |
| __u8 *buf; |
| int b_sent; |
| |
| unsigned int bytes = bitmap_weight(indio_dev->active_scan_mask, |
| indio_dev->masklength) * |
| st->chip_info->channel[0].scan_type.storagebits / 8; |
| |
| buf = kzalloc(indio_dev->scan_bytes, GFP_KERNEL); |
| if (buf == NULL) |
| goto done; |
| |
| b_sent = spi_sync(st->spi, st->ring_msg); |
| if (b_sent) |
| goto done; |
| |
| time_ns = iio_get_time_ns(); |
| |
| memcpy(buf, st->data, bytes); |
| if (indio_dev->scan_timestamp) |
| memcpy(buf + indio_dev->scan_bytes - sizeof(s64), |
| &time_ns, sizeof(time_ns)); |
| |
| iio_push_to_buffer(indio_dev->buffer, buf); |
| done: |
| kfree(buf); |
| iio_trigger_notify_done(indio_dev->trig); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static const struct iio_buffer_setup_ops ad7887_ring_setup_ops = { |
| .preenable = &ad7887_ring_preenable, |
| .postenable = &iio_triggered_buffer_postenable, |
| .predisable = &iio_triggered_buffer_predisable, |
| .postdisable = &ad7887_ring_postdisable, |
| }; |
| |
| int ad7887_register_ring_funcs_and_init(struct iio_dev *indio_dev) |
| { |
| return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, |
| &ad7887_trigger_handler, &ad7887_ring_setup_ops); |
| } |
| |
| void ad7887_ring_cleanup(struct iio_dev *indio_dev) |
| { |
| iio_triggered_buffer_cleanup(indio_dev); |
| } |