| /* |
| * Copyright 2010-2011 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 "../iio.h" |
| #include "../buffer_generic.h" |
| #include "../ring_sw.h" |
| #include "../trigger_consumer.h" |
| |
| #include "ad7887.h" |
| |
| int ad7887_scan_from_ring(struct ad7887_state *st, int channum) |
| { |
| struct iio_buffer *ring = iio_priv_to_dev(st)->buffer; |
| int count = 0, ret; |
| u16 *ring_data; |
| |
| if (!(test_bit(channum, ring->scan_mask))) { |
| ret = -EBUSY; |
| goto error_ret; |
| } |
| |
| 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; |
| |
| /* for single channel scan the result is stored with zero offset */ |
| if ((test_bit(1, ring->scan_mask) || test_bit(0, ring->scan_mask)) && |
| (channum == 1)) |
| count = 1; |
| |
| ret = be16_to_cpu(ring_data[count]); |
| |
| error_free_ring_data: |
| kfree(ring_data); |
| error_ret: |
| return ret; |
| } |
| |
| /** |
| * 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); |
| struct iio_buffer *ring = indio_dev->buffer; |
| |
| st->d_size = ring->scan_count * |
| st->chip_info->channel[0].scan_type.storagebits / 8; |
| |
| if (ring->scan_timestamp) { |
| st->d_size += sizeof(s64); |
| |
| if (st->d_size % sizeof(s64)) |
| st->d_size += sizeof(s64) - (st->d_size % sizeof(s64)); |
| } |
| |
| if (indio_dev->buffer->access->set_bytes_per_datum) |
| indio_dev->buffer->access-> |
| set_bytes_per_datum(indio_dev->buffer, st->d_size); |
| |
| /* We know this is a single long so can 'cheat' */ |
| switch (*ring->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); |
| struct iio_buffer *ring = indio_dev->buffer; |
| s64 time_ns; |
| __u8 *buf; |
| int b_sent; |
| |
| unsigned int bytes = ring->scan_count * |
| st->chip_info->channel[0].scan_type.storagebits / 8; |
| |
| buf = kzalloc(st->d_size, GFP_KERNEL); |
| if (buf == NULL) |
| return -ENOMEM; |
| |
| 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 (ring->scan_timestamp) |
| memcpy(buf + st->d_size - sizeof(s64), |
| &time_ns, sizeof(time_ns)); |
| |
| indio_dev->buffer->access->store_to(indio_dev->buffer, buf, time_ns); |
| 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) |
| { |
| int ret; |
| |
| indio_dev->buffer = iio_sw_rb_allocate(indio_dev); |
| if (!indio_dev->buffer) { |
| ret = -ENOMEM; |
| goto error_ret; |
| } |
| /* Effectively select the ring buffer implementation */ |
| indio_dev->buffer->access = &ring_sw_access_funcs; |
| indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time, |
| &ad7887_trigger_handler, |
| IRQF_ONESHOT, |
| indio_dev, |
| "ad7887_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->buffer->setup_ops = &ad7887_ring_setup_ops; |
| |
| /* 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 ad7887_ring_cleanup(struct iio_dev *indio_dev) |
| { |
| iio_dealloc_pollfunc(indio_dev->pollfunc); |
| iio_sw_rb_free(indio_dev->buffer); |
| } |