| /* |
| * Copyright (C) 2010 Michael Hennerich, Analog Devices Inc. |
| * Copyright (C) 2008-2010 Jonathan Cameron |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * ad799x_ring.c |
| */ |
| |
| #include <linux/interrupt.h> |
| #include <linux/workqueue.h> |
| #include <linux/device.h> |
| #include <linux/slab.h> |
| #include <linux/kernel.h> |
| #include <linux/sysfs.h> |
| #include <linux/list.h> |
| #include <linux/i2c.h> |
| #include <linux/bitops.h> |
| |
| #include "../iio.h" |
| #include "../ring_generic.h" |
| #include "../ring_sw.h" |
| #include "../trigger.h" |
| #include "../sysfs.h" |
| |
| #include "ad799x.h" |
| |
| int ad799x_single_channel_from_ring(struct ad799x_state *st, long mask) |
| { |
| struct iio_ring_buffer *ring = st->indio_dev->ring; |
| int count = 0, ret; |
| u16 *ring_data; |
| |
| if (!(ring->scan_mask & 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; |
| /* Need a count of channels prior to this one */ |
| mask >>= 1; |
| while (mask) { |
| if (mask & ring->scan_mask) |
| count++; |
| mask >>= 1; |
| } |
| |
| ret = be16_to_cpu(ring_data[count]); |
| |
| error_free_ring_data: |
| kfree(ring_data); |
| error_ret: |
| return ret; |
| } |
| |
| /** |
| * ad799x_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 ad799x_ring_preenable(struct iio_dev *indio_dev) |
| { |
| struct iio_ring_buffer *ring = indio_dev->ring; |
| struct ad799x_state *st = indio_dev->dev_data; |
| |
| /* |
| * Need to figure out the current mode based upon the requested |
| * scan mask in iio_dev |
| */ |
| |
| if (st->id == ad7997 || st->id == ad7998) |
| ad799x_set_scan_mode(st, ring->scan_mask); |
| |
| st->d_size = ring->scan_count * 2; |
| |
| 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->ring->access.set_bytes_per_datum) |
| indio_dev->ring->access.set_bytes_per_datum(indio_dev->ring, |
| st->d_size); |
| |
| return 0; |
| } |
| |
| /** |
| * ad799x_poll_func_th() th of trigger launched polling to ring buffer |
| * |
| * As sampling only occurs on i2c comms occuring, leave timestamping until |
| * then. Some triggers will generate their own time stamp. Currently |
| * there is no way of notifying them when no one cares. |
| **/ |
| static void ad799x_poll_func_th(struct iio_dev *indio_dev, s64 time) |
| { |
| struct ad799x_state *st = indio_dev->dev_data; |
| |
| schedule_work(&st->poll_work); |
| |
| return; |
| } |
| /** |
| * ad799x_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 ad799x_poll_bh_to_ring(struct work_struct *work_s) |
| { |
| struct ad799x_state *st = container_of(work_s, struct ad799x_state, |
| poll_work); |
| struct iio_dev *indio_dev = st->indio_dev; |
| struct iio_ring_buffer *ring = indio_dev->ring; |
| struct iio_sw_ring_buffer *ring_sw = iio_to_sw_ring(indio_dev->ring); |
| s64 time_ns; |
| __u8 *rxbuf; |
| int b_sent; |
| u8 cmd; |
| |
| /* Ensure only one copy of this function running at a time */ |
| if (atomic_inc_return(&st->protect_ring) > 1) |
| return; |
| |
| rxbuf = kmalloc(st->d_size, GFP_KERNEL); |
| if (rxbuf == NULL) |
| return; |
| |
| switch (st->id) { |
| case ad7991: |
| case ad7995: |
| case ad7999: |
| cmd = st->config | (ring->scan_mask << AD799X_CHANNEL_SHIFT); |
| break; |
| case ad7992: |
| case ad7993: |
| case ad7994: |
| cmd = (ring->scan_mask << AD799X_CHANNEL_SHIFT) | |
| AD7998_CONV_RES_REG; |
| break; |
| case ad7997: |
| case ad7998: |
| cmd = AD7997_8_READ_SEQUENCE | AD7998_CONV_RES_REG; |
| break; |
| default: |
| cmd = 0; |
| } |
| |
| b_sent = i2c_smbus_read_i2c_block_data(st->client, |
| cmd, ring->scan_count * 2, rxbuf); |
| if (b_sent < 0) |
| goto done; |
| |
| time_ns = iio_get_time_ns(); |
| |
| if (ring->scan_timestamp) |
| memcpy(rxbuf + st->d_size - sizeof(s64), |
| &time_ns, sizeof(time_ns)); |
| |
| ring->access.store_to(&ring_sw->buf, rxbuf, time_ns); |
| done: |
| kfree(rxbuf); |
| atomic_dec(&st->protect_ring); |
| } |
| |
| |
| int ad799x_register_ring_funcs_and_init(struct iio_dev *indio_dev) |
| { |
| struct ad799x_state *st = indio_dev->dev_data; |
| int ret = 0; |
| |
| indio_dev->ring = iio_sw_rb_allocate(indio_dev); |
| if (!indio_dev->ring) { |
| ret = -ENOMEM; |
| goto error_ret; |
| } |
| /* Effectively select the ring buffer implementation */ |
| iio_ring_sw_register_funcs(&st->indio_dev->ring->access); |
| ret = iio_alloc_pollfunc(indio_dev, NULL, &ad799x_poll_func_th); |
| if (ret) |
| goto error_deallocate_sw_rb; |
| |
| /* Ring buffer functions - here trigger setup related */ |
| |
| indio_dev->ring->preenable = &ad799x_ring_preenable; |
| indio_dev->ring->postenable = &iio_triggered_ring_postenable; |
| indio_dev->ring->predisable = &iio_triggered_ring_predisable; |
| indio_dev->ring->scan_timestamp = true; |
| |
| INIT_WORK(&st->poll_work, &ad799x_poll_bh_to_ring); |
| |
| indio_dev->ring->scan_el_attrs = st->chip_info->scan_attrs; |
| |
| /* Flag that polled ring buffering is possible */ |
| indio_dev->modes |= INDIO_RING_TRIGGERED; |
| return 0; |
| error_deallocate_sw_rb: |
| iio_sw_rb_free(indio_dev->ring); |
| error_ret: |
| return ret; |
| } |
| |
| void ad799x_ring_cleanup(struct iio_dev *indio_dev) |
| { |
| /* ensure that the trigger has been detached */ |
| if (indio_dev->trig) { |
| iio_put_trigger(indio_dev->trig); |
| iio_trigger_dettach_poll_func(indio_dev->trig, |
| indio_dev->pollfunc); |
| } |
| kfree(indio_dev->pollfunc); |
| iio_sw_rb_free(indio_dev->ring); |
| } |