| /* |
| * AD7298 SPI ADC driver |
| * |
| * Copyright 2011 Analog Devices Inc. |
| * |
| * Licensed under the GPL-2. |
| */ |
| |
| #include <linux/interrupt.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/spi/spi.h> |
| |
| #include "../iio.h" |
| #include "../buffer.h" |
| #include "../ring_sw.h" |
| #include "../trigger_consumer.h" |
| |
| #include "ad7298.h" |
| |
| /** |
| * ad7298_ring_preenable() setup the parameters of the ring before enabling |
| * |
| * The complex nature of the setting of the number of bytes per datum is due |
| * to this driver currently ensuring that the timestamp is stored at an 8 |
| * byte boundary. |
| **/ |
| static int ad7298_ring_preenable(struct iio_dev *indio_dev) |
| { |
| struct ad7298_state *st = iio_priv(indio_dev); |
| struct iio_buffer *ring = indio_dev->buffer; |
| size_t d_size; |
| int i, m; |
| unsigned short command; |
| int scan_count = bitmap_weight(indio_dev->active_scan_mask, |
| indio_dev->masklength); |
| d_size = scan_count * (AD7298_STORAGE_BITS / 8); |
| |
| if (ring->scan_timestamp) { |
| d_size += sizeof(s64); |
| |
| if (d_size % sizeof(s64)) |
| d_size += sizeof(s64) - (d_size % sizeof(s64)); |
| } |
| |
| if (ring->access->set_bytes_per_datum) |
| ring->access->set_bytes_per_datum(ring, d_size); |
| |
| st->d_size = d_size; |
| |
| command = AD7298_WRITE | st->ext_ref; |
| |
| for (i = 0, m = AD7298_CH(0); i < AD7298_MAX_CHAN; i++, m >>= 1) |
| if (test_bit(i, indio_dev->active_scan_mask)) |
| command |= m; |
| |
| st->tx_buf[0] = cpu_to_be16(command); |
| |
| /* build spi ring message */ |
| st->ring_xfer[0].tx_buf = &st->tx_buf[0]; |
| st->ring_xfer[0].len = 2; |
| st->ring_xfer[0].cs_change = 1; |
| st->ring_xfer[1].tx_buf = &st->tx_buf[1]; |
| st->ring_xfer[1].len = 2; |
| st->ring_xfer[1].cs_change = 1; |
| |
| spi_message_init(&st->ring_msg); |
| spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg); |
| spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg); |
| |
| for (i = 0; i < scan_count; i++) { |
| st->ring_xfer[i + 2].rx_buf = &st->rx_buf[i]; |
| st->ring_xfer[i + 2].len = 2; |
| st->ring_xfer[i + 2].cs_change = 1; |
| spi_message_add_tail(&st->ring_xfer[i + 2], &st->ring_msg); |
| } |
| /* make sure last transfer cs_change is not set */ |
| st->ring_xfer[i + 1].cs_change = 0; |
| |
| return 0; |
| } |
| |
| /** |
| * ad7298_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 ad7298_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *indio_dev = pf->indio_dev; |
| struct ad7298_state *st = iio_priv(indio_dev); |
| struct iio_buffer *ring = indio_dev->buffer; |
| s64 time_ns; |
| __u16 buf[16]; |
| int b_sent, i; |
| |
| b_sent = spi_sync(st->spi, &st->ring_msg); |
| if (b_sent) |
| return b_sent; |
| |
| if (ring->scan_timestamp) { |
| time_ns = iio_get_time_ns(); |
| memcpy((u8 *)buf + st->d_size - sizeof(s64), |
| &time_ns, sizeof(time_ns)); |
| } |
| |
| for (i = 0; i < bitmap_weight(indio_dev->active_scan_mask, |
| indio_dev->masklength); i++) |
| buf[i] = be16_to_cpu(st->rx_buf[i]); |
| |
| indio_dev->buffer->access->store_to(ring, (u8 *)buf, time_ns); |
| iio_trigger_notify_done(indio_dev->trig); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static const struct iio_buffer_setup_ops ad7298_ring_setup_ops = { |
| .preenable = &ad7298_ring_preenable, |
| .postenable = &iio_triggered_buffer_postenable, |
| .predisable = &iio_triggered_buffer_predisable, |
| }; |
| |
| int ad7298_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; |
| } |
| indio_dev->pollfunc = iio_alloc_pollfunc(NULL, |
| &ad7298_trigger_handler, |
| IRQF_ONESHOT, |
| indio_dev, |
| "ad7298_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->setup_ops = &ad7298_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 ad7298_ring_cleanup(struct iio_dev *indio_dev) |
| { |
| iio_dealloc_pollfunc(indio_dev->pollfunc); |
| iio_sw_rb_free(indio_dev->buffer); |
| } |