| /* |
| * Copyright 2010 Analog Devices Inc. |
| * Copyright (C) 2008 Jonathan Cameron |
| * |
| * Licensed under the GPL-2 or later. |
| * |
| * ad7476_ring.c |
| */ |
| |
| #include <linux/interrupt.h> |
| #include <linux/device.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 "ad7476.h" |
| |
| int ad7476_scan_from_ring(struct iio_dev *indio_dev) |
| { |
| struct iio_buffer *ring = indio_dev->buffer; |
| int ret; |
| u8 *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, ring_data); |
| if (ret) |
| goto error_free_ring_data; |
| |
| ret = (ring_data[0] << 8) | ring_data[1]; |
| |
| error_free_ring_data: |
| kfree(ring_data); |
| error_ret: |
| return ret; |
| } |
| |
| /** |
| * ad7476_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 ad7476_ring_preenable(struct iio_dev *indio_dev) |
| { |
| struct ad7476_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); |
| |
| return 0; |
| } |
| |
| static irqreturn_t ad7476_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *indio_dev = pf->indio_dev; |
| struct ad7476_state *st = iio_priv(indio_dev); |
| s64 time_ns; |
| __u8 *rxbuf; |
| int b_sent; |
| |
| rxbuf = kzalloc(st->d_size, GFP_KERNEL); |
| if (rxbuf == NULL) |
| return -ENOMEM; |
| |
| b_sent = spi_read(st->spi, rxbuf, |
| st->chip_info->channel[0].scan_type.storagebits / 8); |
| if (b_sent < 0) |
| goto done; |
| |
| time_ns = iio_get_time_ns(); |
| |
| if (indio_dev->buffer->scan_timestamp) |
| memcpy(rxbuf + st->d_size - sizeof(s64), |
| &time_ns, sizeof(time_ns)); |
| |
| indio_dev->buffer->access->store_to(indio_dev->buffer, rxbuf, time_ns); |
| done: |
| iio_trigger_notify_done(indio_dev->trig); |
| kfree(rxbuf); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static const struct iio_buffer_setup_ops ad7476_ring_setup_ops = { |
| .preenable = &ad7476_ring_preenable, |
| .postenable = &iio_triggered_buffer_postenable, |
| .predisable = &iio_triggered_buffer_predisable, |
| }; |
| |
| int ad7476_register_ring_funcs_and_init(struct iio_dev *indio_dev) |
| { |
| struct ad7476_state *st = iio_priv(indio_dev); |
| int ret = 0; |
| |
| 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(NULL, |
| &ad7476_trigger_handler, |
| IRQF_ONESHOT, |
| indio_dev, |
| "%s_consumer%d", |
| spi_get_device_id(st->spi)->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->buffer->setup_ops = &ad7476_ring_setup_ops; |
| indio_dev->buffer->scan_timestamp = true; |
| |
| /* 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 ad7476_ring_cleanup(struct iio_dev *indio_dev) |
| { |
| iio_dealloc_pollfunc(indio_dev->pollfunc); |
| iio_sw_rb_free(indio_dev->buffer); |
| } |