201 lines
4.9 KiB
C
201 lines
4.9 KiB
C
/*
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* Copyright (C) 2008 Jonathan Cameron
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* max1363_ring.c
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*/
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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/i2c.h>
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#include <linux/bitops.h>
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#include "../iio.h"
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#include "../ring_generic.h"
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#include "../ring_sw.h"
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#include "../trigger_consumer.h"
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#include "max1363.h"
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int max1363_single_channel_from_ring(long mask, struct max1363_state *st)
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{
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struct iio_ring_buffer *ring = iio_priv_to_dev(st)->ring;
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int count = 0, ret;
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u8 *ring_data;
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if (!(st->current_mode->modemask & mask)) {
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ret = -EBUSY;
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goto error_ret;
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}
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ring_data = kmalloc(ring->access->get_bytes_per_datum(ring),
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GFP_KERNEL);
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if (ring_data == NULL) {
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ret = -ENOMEM;
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goto error_ret;
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}
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ret = ring->access->read_last(ring, ring_data);
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if (ret)
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goto error_free_ring_data;
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/* Need a count of channels prior to this one */
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mask >>= 1;
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while (mask) {
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if (mask & st->current_mode->modemask)
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count++;
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mask >>= 1;
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}
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if (st->chip_info->bits != 8)
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ret = ((int)(ring_data[count*2 + 0] & 0x0F) << 8)
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+ (int)(ring_data[count*2 + 1]);
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else
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ret = ring_data[count];
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error_free_ring_data:
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kfree(ring_data);
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error_ret:
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return ret;
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}
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/**
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* max1363_ring_preenable() - setup the parameters of the ring before enabling
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*
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* The complex nature of the setting of the nuber of bytes per datum is due
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* to this driver currently ensuring that the timestamp is stored at an 8
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* byte boundary.
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**/
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static int max1363_ring_preenable(struct iio_dev *indio_dev)
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{
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struct max1363_state *st = iio_priv(indio_dev);
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struct iio_ring_buffer *ring = indio_dev->ring;
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size_t d_size = 0;
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unsigned long numvals;
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/*
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* Need to figure out the current mode based upon the requested
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* scan mask in iio_dev
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*/
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st->current_mode = max1363_match_mode(ring->scan_mask,
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st->chip_info);
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if (!st->current_mode)
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return -EINVAL;
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max1363_set_scan_mode(st);
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numvals = hweight_long(st->current_mode->modemask);
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if (ring->access->set_bytes_per_datum) {
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if (ring->scan_timestamp)
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d_size += sizeof(s64);
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if (st->chip_info->bits != 8)
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d_size += numvals*2;
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else
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d_size += numvals;
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if (ring->scan_timestamp && (d_size % 8))
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d_size += 8 - (d_size % 8);
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ring->access->set_bytes_per_datum(ring, d_size);
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}
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return 0;
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}
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static irqreturn_t max1363_trigger_handler(int irq, void *p)
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{
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struct iio_poll_func *pf = p;
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struct iio_dev *indio_dev = pf->indio_dev;
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struct max1363_state *st = iio_priv(indio_dev);
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s64 time_ns;
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__u8 *rxbuf;
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int b_sent;
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size_t d_size;
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unsigned long numvals = hweight_long(st->current_mode->modemask);
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/* Ensure the timestamp is 8 byte aligned */
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if (st->chip_info->bits != 8)
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d_size = numvals*2 + sizeof(s64);
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else
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d_size = numvals + sizeof(s64);
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if (d_size % sizeof(s64))
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d_size += sizeof(s64) - (d_size % sizeof(s64));
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/* Monitor mode prevents reading. Whilst not currently implemented
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* might as well have this test in here in the meantime as it does
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* no harm.
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*/
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if (numvals == 0)
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return IRQ_HANDLED;
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rxbuf = kmalloc(d_size, GFP_KERNEL);
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if (rxbuf == NULL)
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return -ENOMEM;
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if (st->chip_info->bits != 8)
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b_sent = i2c_master_recv(st->client, rxbuf, numvals*2);
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else
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b_sent = i2c_master_recv(st->client, rxbuf, numvals);
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if (b_sent < 0)
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goto done;
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time_ns = iio_get_time_ns();
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memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
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indio_dev->ring->access->store_to(indio_dev->ring, rxbuf, time_ns);
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done:
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iio_trigger_notify_done(indio_dev->trig);
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kfree(rxbuf);
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return IRQ_HANDLED;
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}
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static const struct iio_ring_setup_ops max1363_ring_setup_ops = {
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.postenable = &iio_triggered_ring_postenable,
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.preenable = &max1363_ring_preenable,
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.predisable = &iio_triggered_ring_predisable,
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};
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int max1363_register_ring_funcs_and_init(struct iio_dev *indio_dev)
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{
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struct max1363_state *st = iio_priv(indio_dev);
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int ret = 0;
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indio_dev->ring = iio_sw_rb_allocate(indio_dev);
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if (!indio_dev->ring) {
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ret = -ENOMEM;
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goto error_ret;
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}
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indio_dev->pollfunc = iio_alloc_pollfunc(NULL,
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&max1363_trigger_handler,
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IRQF_ONESHOT,
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indio_dev,
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"%s_consumer%d",
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st->client->name,
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indio_dev->id);
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if (indio_dev->pollfunc == NULL) {
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ret = -ENOMEM;
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goto error_deallocate_sw_rb;
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}
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/* Effectively select the ring buffer implementation */
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indio_dev->ring->access = &ring_sw_access_funcs;
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/* Ring buffer functions - here trigger setup related */
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indio_dev->ring->setup_ops = &max1363_ring_setup_ops;
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/* Flag that polled ring buffering is possible */
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indio_dev->modes |= INDIO_RING_TRIGGERED;
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return 0;
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error_deallocate_sw_rb:
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iio_sw_rb_free(indio_dev->ring);
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error_ret:
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return ret;
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}
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void max1363_ring_cleanup(struct iio_dev *indio_dev)
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{
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/* ensure that the trigger has been detached */
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iio_dealloc_pollfunc(indio_dev->pollfunc);
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iio_sw_rb_free(indio_dev->ring);
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}
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