/drivers/staging/iio/adc/max1363_ring.c
https://bitbucket.org/wisechild/galaxy-nexus · C · 209 lines · 152 code · 27 blank · 30 comment · 29 complexity · d121b13ce3867a0ab013d5fbe7b0622e MD5 · raw file
- /*
- * Copyright (C) 2008 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.
- *
- * max1363_ring.c
- */
- #include <linux/interrupt.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 "max1363.h"
- int max1363_single_channel_from_ring(long mask, struct max1363_state *st)
- {
- struct iio_ring_buffer *ring = iio_priv_to_dev(st)->ring;
- int count = 0, ret;
- u8 *ring_data;
- if (!(st->current_mode->modemask & 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, ring_data);
- if (ret)
- goto error_free_ring_data;
- /* Need a count of channels prior to this one */
- mask >>= 1;
- while (mask) {
- if (mask & st->current_mode->modemask)
- count++;
- mask >>= 1;
- }
- if (st->chip_info->bits != 8)
- ret = ((int)(ring_data[count*2 + 0] & 0x0F) << 8)
- + (int)(ring_data[count*2 + 1]);
- else
- ret = ring_data[count];
- error_free_ring_data:
- kfree(ring_data);
- error_ret:
- return ret;
- }
- /**
- * max1363_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 max1363_ring_preenable(struct iio_dev *indio_dev)
- {
- struct max1363_state *st = iio_priv(indio_dev);
- struct iio_ring_buffer *ring = indio_dev->ring;
- size_t d_size = 0;
- unsigned long numvals;
- /*
- * Need to figure out the current mode based upon the requested
- * scan mask in iio_dev
- */
- st->current_mode = max1363_match_mode(ring->scan_mask,
- st->chip_info);
- if (!st->current_mode)
- return -EINVAL;
- max1363_set_scan_mode(st);
- numvals = hweight_long(st->current_mode->modemask);
- if (ring->access->set_bytes_per_datum) {
- if (ring->scan_timestamp)
- d_size += sizeof(s64);
- if (st->chip_info->bits != 8)
- d_size += numvals*2;
- else
- d_size += numvals;
- if (ring->scan_timestamp && (d_size % 8))
- d_size += 8 - (d_size % 8);
- ring->access->set_bytes_per_datum(ring, d_size);
- }
- return 0;
- }
- static irqreturn_t max1363_trigger_handler(int irq, void *p)
- {
- struct iio_poll_func *pf = p;
- struct iio_dev *indio_dev = pf->private_data;
- struct max1363_state *st = iio_priv(indio_dev);
- s64 time_ns;
- __u8 *rxbuf;
- int b_sent;
- size_t d_size;
- unsigned long numvals = hweight_long(st->current_mode->modemask);
- /* Ensure the timestamp is 8 byte aligned */
- if (st->chip_info->bits != 8)
- d_size = numvals*2 + sizeof(s64);
- else
- d_size = numvals + sizeof(s64);
- if (d_size % sizeof(s64))
- d_size += sizeof(s64) - (d_size % sizeof(s64));
- /* Monitor mode prevents reading. Whilst not currently implemented
- * might as well have this test in here in the meantime as it does
- * no harm.
- */
- if (numvals == 0)
- return IRQ_HANDLED;
- rxbuf = kmalloc(d_size, GFP_KERNEL);
- if (rxbuf == NULL)
- return -ENOMEM;
- if (st->chip_info->bits != 8)
- b_sent = i2c_master_recv(st->client, rxbuf, numvals*2);
- else
- b_sent = i2c_master_recv(st->client, rxbuf, numvals);
- if (b_sent < 0)
- goto done;
- time_ns = iio_get_time_ns();
- memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
- indio_dev->ring->access->store_to(indio_dev->ring, rxbuf, time_ns);
- done:
- iio_trigger_notify_done(indio_dev->trig);
- kfree(rxbuf);
- return IRQ_HANDLED;
- }
- static const struct iio_ring_setup_ops max1363_ring_setup_ops = {
- .postenable = &iio_triggered_ring_postenable,
- .preenable = &max1363_ring_preenable,
- .predisable = &iio_triggered_ring_predisable,
- };
- int max1363_register_ring_funcs_and_init(struct iio_dev *indio_dev)
- {
- struct max1363_state *st = iio_priv(indio_dev);
- int ret = 0;
- indio_dev->ring = iio_sw_rb_allocate(indio_dev);
- if (!indio_dev->ring) {
- ret = -ENOMEM;
- goto error_ret;
- }
- indio_dev->pollfunc = iio_alloc_pollfunc(NULL,
- &max1363_trigger_handler,
- IRQF_ONESHOT,
- indio_dev,
- "%s_consumer%d",
- st->client->name,
- indio_dev->id);
- if (indio_dev->pollfunc == NULL) {
- ret = -ENOMEM;
- goto error_deallocate_sw_rb;
- }
- /* Effectively select the ring buffer implementation */
- indio_dev->ring->access = &ring_sw_access_funcs;
- /* Ring buffer functions - here trigger setup related */
- indio_dev->ring->setup_ops = &max1363_ring_setup_ops;
- /* 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 max1363_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);
- }
- iio_dealloc_pollfunc(indio_dev->pollfunc);
- iio_sw_rb_free(indio_dev->ring);
- }