![Octavian Purdila](/assets/img/avatar_default.png)
Some devices have hardware buffers that can store a number of samples for later consumption. Hardware usually provides interrupts to notify the processor when the FIFO is full or when it has reached a certain watermark level. This helps with reducing the number of interrupts to the host processor and thus it helps decreasing the power consumption. This patch enables usage of hardware FIFOs for IIO devices in conjunction with software device buffers. When the hardware FIFO is enabled the samples are stored in the hardware FIFO. The samples are later flushed to the device software buffer when the number of entries in the hardware FIFO reaches the hardware watermark or when a flush operation is triggered by the user when doing a non-blocking read on an empty software device buffer. In order to implement hardware FIFO support the device drivers must implement the following new operations: setting and getting the hardware FIFO watermark level, flushing the hardware FIFO to the software device buffer. The device must also expose information about the hardware FIFO such it's minimum and maximum watermark and if necessary a list of supported watermark values. Finally, the device driver must activate the hardware FIFO when the device buffer is enabled, if the current device settings allows it. The software device buffer watermark is passed by the IIO core to the device driver as a hint for the hardware FIFO watermark. The device driver can adjust this value to allow for hardware limitations (such as capping it to the maximum hardware watermark or adjust it to a value that is supported by the hardware). It can also disable the hardware watermark (and implicitly the hardware FIFO) it this value is below the minimum hardware watermark. Since a driver may support hardware FIFO only when not in triggered buffer mode (due to different semantics of hardware FIFO sampling and triggered sampling) this patch changes the IIO core code to allow falling back to non-triggered buffered mode if no trigger is enabled. Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
1263 lines
31 KiB
C
1263 lines
31 KiB
C
/* The industrial I/O core
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*
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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 it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* Handling of buffer allocation / resizing.
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*
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*
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* Things to look at here.
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* - Better memory allocation techniques?
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* - Alternative access techniques?
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*/
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/device.h>
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#include <linux/fs.h>
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#include <linux/cdev.h>
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#include <linux/slab.h>
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#include <linux/poll.h>
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#include <linux/sched.h>
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#include <linux/iio/iio.h>
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#include "iio_core.h"
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#include <linux/iio/sysfs.h>
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#include <linux/iio/buffer.h>
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static const char * const iio_endian_prefix[] = {
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[IIO_BE] = "be",
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[IIO_LE] = "le",
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};
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static bool iio_buffer_is_active(struct iio_buffer *buf)
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{
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return !list_empty(&buf->buffer_list);
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}
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static size_t iio_buffer_data_available(struct iio_buffer *buf)
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{
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return buf->access->data_available(buf);
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}
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static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev,
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struct iio_buffer *buf, size_t required)
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{
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if (!indio_dev->info->hwfifo_flush_to_buffer)
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return -ENODEV;
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return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required);
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}
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static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
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size_t to_wait, int to_flush)
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{
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size_t avail;
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int flushed = 0;
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/* wakeup if the device was unregistered */
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if (!indio_dev->info)
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return true;
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/* drain the buffer if it was disabled */
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if (!iio_buffer_is_active(buf)) {
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to_wait = min_t(size_t, to_wait, 1);
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to_flush = 0;
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}
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avail = iio_buffer_data_available(buf);
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if (avail >= to_wait) {
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/* force a flush for non-blocking reads */
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if (!to_wait && !avail && to_flush)
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iio_buffer_flush_hwfifo(indio_dev, buf, to_flush);
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return true;
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}
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if (to_flush)
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flushed = iio_buffer_flush_hwfifo(indio_dev, buf,
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to_wait - avail);
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if (flushed <= 0)
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return false;
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if (avail + flushed >= to_wait)
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return true;
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return false;
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}
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/**
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* iio_buffer_read_first_n_outer() - chrdev read for buffer access
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*
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* This function relies on all buffer implementations having an
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* iio_buffer as their first element.
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**/
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ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
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size_t n, loff_t *f_ps)
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{
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struct iio_dev *indio_dev = filp->private_data;
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struct iio_buffer *rb = indio_dev->buffer;
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size_t datum_size;
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size_t to_wait = 0;
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size_t to_read;
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int ret;
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if (!indio_dev->info)
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return -ENODEV;
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if (!rb || !rb->access->read_first_n)
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return -EINVAL;
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datum_size = rb->bytes_per_datum;
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/*
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* If datum_size is 0 there will never be anything to read from the
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* buffer, so signal end of file now.
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*/
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if (!datum_size)
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return 0;
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to_read = min_t(size_t, n / datum_size, rb->watermark);
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if (!(filp->f_flags & O_NONBLOCK))
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to_wait = to_read;
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do {
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ret = wait_event_interruptible(rb->pollq,
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iio_buffer_ready(indio_dev, rb, to_wait, to_read));
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if (ret)
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return ret;
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if (!indio_dev->info)
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return -ENODEV;
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ret = rb->access->read_first_n(rb, n, buf);
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if (ret == 0 && (filp->f_flags & O_NONBLOCK))
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ret = -EAGAIN;
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} while (ret == 0);
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return ret;
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}
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/**
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* iio_buffer_poll() - poll the buffer to find out if it has data
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*/
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unsigned int iio_buffer_poll(struct file *filp,
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struct poll_table_struct *wait)
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{
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struct iio_dev *indio_dev = filp->private_data;
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struct iio_buffer *rb = indio_dev->buffer;
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if (!indio_dev->info)
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return -ENODEV;
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poll_wait(filp, &rb->pollq, wait);
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if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
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return POLLIN | POLLRDNORM;
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return 0;
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}
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/**
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* iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
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* @indio_dev: The IIO device
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*
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* Wakes up the event waitqueue used for poll(). Should usually
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* be called when the device is unregistered.
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*/
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void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
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{
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if (!indio_dev->buffer)
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return;
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wake_up(&indio_dev->buffer->pollq);
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}
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void iio_buffer_init(struct iio_buffer *buffer)
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{
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INIT_LIST_HEAD(&buffer->demux_list);
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INIT_LIST_HEAD(&buffer->buffer_list);
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init_waitqueue_head(&buffer->pollq);
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kref_init(&buffer->ref);
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buffer->watermark = 1;
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}
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EXPORT_SYMBOL(iio_buffer_init);
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static ssize_t iio_show_scan_index(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
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}
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static ssize_t iio_show_fixed_type(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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u8 type = this_attr->c->scan_type.endianness;
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if (type == IIO_CPU) {
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#ifdef __LITTLE_ENDIAN
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type = IIO_LE;
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#else
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type = IIO_BE;
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#endif
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}
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if (this_attr->c->scan_type.repeat > 1)
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return sprintf(buf, "%s:%c%d/%dX%d>>%u\n",
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iio_endian_prefix[type],
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this_attr->c->scan_type.sign,
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this_attr->c->scan_type.realbits,
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this_attr->c->scan_type.storagebits,
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this_attr->c->scan_type.repeat,
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this_attr->c->scan_type.shift);
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else
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return sprintf(buf, "%s:%c%d/%d>>%u\n",
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iio_endian_prefix[type],
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this_attr->c->scan_type.sign,
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this_attr->c->scan_type.realbits,
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this_attr->c->scan_type.storagebits,
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this_attr->c->scan_type.shift);
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}
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static ssize_t iio_scan_el_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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int ret;
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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/* Ensure ret is 0 or 1. */
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ret = !!test_bit(to_iio_dev_attr(attr)->address,
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indio_dev->buffer->scan_mask);
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return sprintf(buf, "%d\n", ret);
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}
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/* Note NULL used as error indicator as it doesn't make sense. */
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static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
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unsigned int masklength,
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const unsigned long *mask)
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{
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if (bitmap_empty(mask, masklength))
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return NULL;
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while (*av_masks) {
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if (bitmap_subset(mask, av_masks, masklength))
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return av_masks;
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av_masks += BITS_TO_LONGS(masklength);
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}
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return NULL;
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}
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static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
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const unsigned long *mask)
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{
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if (!indio_dev->setup_ops->validate_scan_mask)
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return true;
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return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
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}
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/**
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* iio_scan_mask_set() - set particular bit in the scan mask
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* @indio_dev: the iio device
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* @buffer: the buffer whose scan mask we are interested in
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* @bit: the bit to be set.
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*
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* Note that at this point we have no way of knowing what other
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* buffers might request, hence this code only verifies that the
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* individual buffers request is plausible.
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*/
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static int iio_scan_mask_set(struct iio_dev *indio_dev,
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struct iio_buffer *buffer, int bit)
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{
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const unsigned long *mask;
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unsigned long *trialmask;
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trialmask = kmalloc(sizeof(*trialmask)*
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BITS_TO_LONGS(indio_dev->masklength),
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GFP_KERNEL);
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if (trialmask == NULL)
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return -ENOMEM;
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if (!indio_dev->masklength) {
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WARN_ON("Trying to set scanmask prior to registering buffer\n");
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goto err_invalid_mask;
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}
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bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
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set_bit(bit, trialmask);
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if (!iio_validate_scan_mask(indio_dev, trialmask))
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goto err_invalid_mask;
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if (indio_dev->available_scan_masks) {
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mask = iio_scan_mask_match(indio_dev->available_scan_masks,
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indio_dev->masklength,
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trialmask);
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if (!mask)
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goto err_invalid_mask;
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}
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bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
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kfree(trialmask);
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return 0;
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err_invalid_mask:
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kfree(trialmask);
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return -EINVAL;
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}
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static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
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{
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clear_bit(bit, buffer->scan_mask);
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return 0;
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}
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static ssize_t iio_scan_el_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len)
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{
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int ret;
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bool state;
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct iio_buffer *buffer = indio_dev->buffer;
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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ret = strtobool(buf, &state);
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if (ret < 0)
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return ret;
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mutex_lock(&indio_dev->mlock);
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if (iio_buffer_is_active(indio_dev->buffer)) {
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ret = -EBUSY;
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goto error_ret;
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}
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ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
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if (ret < 0)
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goto error_ret;
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if (!state && ret) {
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ret = iio_scan_mask_clear(buffer, this_attr->address);
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if (ret)
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goto error_ret;
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} else if (state && !ret) {
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ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
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if (ret)
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goto error_ret;
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}
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error_ret:
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mutex_unlock(&indio_dev->mlock);
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return ret < 0 ? ret : len;
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}
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static ssize_t iio_scan_el_ts_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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return sprintf(buf, "%d\n", indio_dev->buffer->scan_timestamp);
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}
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static ssize_t iio_scan_el_ts_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len)
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{
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int ret;
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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bool state;
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ret = strtobool(buf, &state);
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if (ret < 0)
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return ret;
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mutex_lock(&indio_dev->mlock);
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if (iio_buffer_is_active(indio_dev->buffer)) {
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ret = -EBUSY;
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goto error_ret;
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}
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indio_dev->buffer->scan_timestamp = state;
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error_ret:
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mutex_unlock(&indio_dev->mlock);
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return ret ? ret : len;
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}
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static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan)
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{
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int ret, attrcount = 0;
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struct iio_buffer *buffer = indio_dev->buffer;
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ret = __iio_add_chan_devattr("index",
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chan,
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&iio_show_scan_index,
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NULL,
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0,
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IIO_SEPARATE,
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&indio_dev->dev,
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&buffer->scan_el_dev_attr_list);
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if (ret)
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return ret;
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attrcount++;
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ret = __iio_add_chan_devattr("type",
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chan,
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&iio_show_fixed_type,
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NULL,
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0,
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0,
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&indio_dev->dev,
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&buffer->scan_el_dev_attr_list);
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if (ret)
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return ret;
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attrcount++;
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if (chan->type != IIO_TIMESTAMP)
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ret = __iio_add_chan_devattr("en",
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chan,
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&iio_scan_el_show,
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&iio_scan_el_store,
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chan->scan_index,
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0,
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&indio_dev->dev,
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&buffer->scan_el_dev_attr_list);
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else
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ret = __iio_add_chan_devattr("en",
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chan,
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&iio_scan_el_ts_show,
|
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&iio_scan_el_ts_store,
|
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chan->scan_index,
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0,
|
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&indio_dev->dev,
|
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&buffer->scan_el_dev_attr_list);
|
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if (ret)
|
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return ret;
|
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attrcount++;
|
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ret = attrcount;
|
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return ret;
|
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}
|
|
|
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static ssize_t iio_buffer_read_length(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
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struct iio_buffer *buffer = indio_dev->buffer;
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|
|
return sprintf(buf, "%d\n", buffer->length);
|
|
}
|
|
|
|
static ssize_t iio_buffer_write_length(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t len)
|
|
{
|
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
|
struct iio_buffer *buffer = indio_dev->buffer;
|
|
unsigned int val;
|
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int ret;
|
|
|
|
ret = kstrtouint(buf, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (val == buffer->length)
|
|
return len;
|
|
|
|
mutex_lock(&indio_dev->mlock);
|
|
if (iio_buffer_is_active(indio_dev->buffer)) {
|
|
ret = -EBUSY;
|
|
} else {
|
|
buffer->access->set_length(buffer, val);
|
|
ret = 0;
|
|
}
|
|
if (ret)
|
|
goto out;
|
|
if (buffer->length && buffer->length < buffer->watermark)
|
|
buffer->watermark = buffer->length;
|
|
out:
|
|
mutex_unlock(&indio_dev->mlock);
|
|
|
|
return ret ? ret : len;
|
|
}
|
|
|
|
static ssize_t iio_buffer_show_enable(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
|
return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer));
|
|
}
|
|
|
|
static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
|
|
const unsigned long *mask, bool timestamp)
|
|
{
|
|
const struct iio_chan_spec *ch;
|
|
unsigned bytes = 0;
|
|
int length, i;
|
|
|
|
/* How much space will the demuxed element take? */
|
|
for_each_set_bit(i, mask,
|
|
indio_dev->masklength) {
|
|
ch = iio_find_channel_from_si(indio_dev, i);
|
|
if (ch->scan_type.repeat > 1)
|
|
length = ch->scan_type.storagebits / 8 *
|
|
ch->scan_type.repeat;
|
|
else
|
|
length = ch->scan_type.storagebits / 8;
|
|
bytes = ALIGN(bytes, length);
|
|
bytes += length;
|
|
}
|
|
if (timestamp) {
|
|
ch = iio_find_channel_from_si(indio_dev,
|
|
indio_dev->scan_index_timestamp);
|
|
if (ch->scan_type.repeat > 1)
|
|
length = ch->scan_type.storagebits / 8 *
|
|
ch->scan_type.repeat;
|
|
else
|
|
length = ch->scan_type.storagebits / 8;
|
|
bytes = ALIGN(bytes, length);
|
|
bytes += length;
|
|
}
|
|
return bytes;
|
|
}
|
|
|
|
static void iio_buffer_activate(struct iio_dev *indio_dev,
|
|
struct iio_buffer *buffer)
|
|
{
|
|
iio_buffer_get(buffer);
|
|
list_add(&buffer->buffer_list, &indio_dev->buffer_list);
|
|
}
|
|
|
|
static void iio_buffer_deactivate(struct iio_buffer *buffer)
|
|
{
|
|
list_del_init(&buffer->buffer_list);
|
|
wake_up_interruptible(&buffer->pollq);
|
|
iio_buffer_put(buffer);
|
|
}
|
|
|
|
void iio_disable_all_buffers(struct iio_dev *indio_dev)
|
|
{
|
|
struct iio_buffer *buffer, *_buffer;
|
|
|
|
if (list_empty(&indio_dev->buffer_list))
|
|
return;
|
|
|
|
if (indio_dev->setup_ops->predisable)
|
|
indio_dev->setup_ops->predisable(indio_dev);
|
|
|
|
list_for_each_entry_safe(buffer, _buffer,
|
|
&indio_dev->buffer_list, buffer_list)
|
|
iio_buffer_deactivate(buffer);
|
|
|
|
indio_dev->currentmode = INDIO_DIRECT_MODE;
|
|
if (indio_dev->setup_ops->postdisable)
|
|
indio_dev->setup_ops->postdisable(indio_dev);
|
|
|
|
if (indio_dev->available_scan_masks == NULL)
|
|
kfree(indio_dev->active_scan_mask);
|
|
}
|
|
|
|
static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
|
|
struct iio_buffer *buffer)
|
|
{
|
|
unsigned int bytes;
|
|
|
|
if (!buffer->access->set_bytes_per_datum)
|
|
return;
|
|
|
|
bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
|
|
buffer->scan_timestamp);
|
|
|
|
buffer->access->set_bytes_per_datum(buffer, bytes);
|
|
}
|
|
|
|
static int __iio_update_buffers(struct iio_dev *indio_dev,
|
|
struct iio_buffer *insert_buffer,
|
|
struct iio_buffer *remove_buffer)
|
|
{
|
|
int ret;
|
|
int success = 0;
|
|
struct iio_buffer *buffer;
|
|
unsigned long *compound_mask;
|
|
const unsigned long *old_mask;
|
|
|
|
/* Wind down existing buffers - iff there are any */
|
|
if (!list_empty(&indio_dev->buffer_list)) {
|
|
if (indio_dev->setup_ops->predisable) {
|
|
ret = indio_dev->setup_ops->predisable(indio_dev);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
indio_dev->currentmode = INDIO_DIRECT_MODE;
|
|
if (indio_dev->setup_ops->postdisable) {
|
|
ret = indio_dev->setup_ops->postdisable(indio_dev);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
}
|
|
/* Keep a copy of current setup to allow roll back */
|
|
old_mask = indio_dev->active_scan_mask;
|
|
if (!indio_dev->available_scan_masks)
|
|
indio_dev->active_scan_mask = NULL;
|
|
|
|
if (remove_buffer)
|
|
iio_buffer_deactivate(remove_buffer);
|
|
if (insert_buffer)
|
|
iio_buffer_activate(indio_dev, insert_buffer);
|
|
|
|
/* If no buffers in list, we are done */
|
|
if (list_empty(&indio_dev->buffer_list)) {
|
|
indio_dev->currentmode = INDIO_DIRECT_MODE;
|
|
if (indio_dev->available_scan_masks == NULL)
|
|
kfree(old_mask);
|
|
return 0;
|
|
}
|
|
|
|
/* What scan mask do we actually have? */
|
|
compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
|
|
sizeof(long), GFP_KERNEL);
|
|
if (compound_mask == NULL) {
|
|
if (indio_dev->available_scan_masks == NULL)
|
|
kfree(old_mask);
|
|
return -ENOMEM;
|
|
}
|
|
indio_dev->scan_timestamp = 0;
|
|
|
|
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
|
|
bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
|
|
indio_dev->masklength);
|
|
indio_dev->scan_timestamp |= buffer->scan_timestamp;
|
|
}
|
|
if (indio_dev->available_scan_masks) {
|
|
indio_dev->active_scan_mask =
|
|
iio_scan_mask_match(indio_dev->available_scan_masks,
|
|
indio_dev->masklength,
|
|
compound_mask);
|
|
if (indio_dev->active_scan_mask == NULL) {
|
|
/*
|
|
* Roll back.
|
|
* Note can only occur when adding a buffer.
|
|
*/
|
|
iio_buffer_deactivate(insert_buffer);
|
|
if (old_mask) {
|
|
indio_dev->active_scan_mask = old_mask;
|
|
success = -EINVAL;
|
|
}
|
|
else {
|
|
kfree(compound_mask);
|
|
ret = -EINVAL;
|
|
return ret;
|
|
}
|
|
}
|
|
} else {
|
|
indio_dev->active_scan_mask = compound_mask;
|
|
}
|
|
|
|
iio_update_demux(indio_dev);
|
|
|
|
/* Wind up again */
|
|
if (indio_dev->setup_ops->preenable) {
|
|
ret = indio_dev->setup_ops->preenable(indio_dev);
|
|
if (ret) {
|
|
printk(KERN_ERR
|
|
"Buffer not started: buffer preenable failed (%d)\n", ret);
|
|
goto error_remove_inserted;
|
|
}
|
|
}
|
|
indio_dev->scan_bytes =
|
|
iio_compute_scan_bytes(indio_dev,
|
|
indio_dev->active_scan_mask,
|
|
indio_dev->scan_timestamp);
|
|
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
|
|
iio_buffer_update_bytes_per_datum(indio_dev, buffer);
|
|
if (buffer->access->request_update) {
|
|
ret = buffer->access->request_update(buffer);
|
|
if (ret) {
|
|
printk(KERN_INFO
|
|
"Buffer not started: buffer parameter update failed (%d)\n", ret);
|
|
goto error_run_postdisable;
|
|
}
|
|
}
|
|
}
|
|
if (indio_dev->info->update_scan_mode) {
|
|
ret = indio_dev->info
|
|
->update_scan_mode(indio_dev,
|
|
indio_dev->active_scan_mask);
|
|
if (ret < 0) {
|
|
printk(KERN_INFO "Buffer not started: update scan mode failed (%d)\n", ret);
|
|
goto error_run_postdisable;
|
|
}
|
|
}
|
|
/* Definitely possible for devices to support both of these. */
|
|
if ((indio_dev->modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) {
|
|
indio_dev->currentmode = INDIO_BUFFER_TRIGGERED;
|
|
} else if (indio_dev->modes & INDIO_BUFFER_HARDWARE) {
|
|
indio_dev->currentmode = INDIO_BUFFER_HARDWARE;
|
|
} else if (indio_dev->modes & INDIO_BUFFER_SOFTWARE) {
|
|
indio_dev->currentmode = INDIO_BUFFER_SOFTWARE;
|
|
} else { /* Should never be reached */
|
|
/* Can only occur on first buffer */
|
|
if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
|
|
pr_info("Buffer not started: no trigger\n");
|
|
ret = -EINVAL;
|
|
goto error_run_postdisable;
|
|
}
|
|
|
|
if (indio_dev->setup_ops->postenable) {
|
|
ret = indio_dev->setup_ops->postenable(indio_dev);
|
|
if (ret) {
|
|
printk(KERN_INFO
|
|
"Buffer not started: postenable failed (%d)\n", ret);
|
|
indio_dev->currentmode = INDIO_DIRECT_MODE;
|
|
if (indio_dev->setup_ops->postdisable)
|
|
indio_dev->setup_ops->postdisable(indio_dev);
|
|
goto error_disable_all_buffers;
|
|
}
|
|
}
|
|
|
|
if (indio_dev->available_scan_masks)
|
|
kfree(compound_mask);
|
|
else
|
|
kfree(old_mask);
|
|
|
|
return success;
|
|
|
|
error_disable_all_buffers:
|
|
indio_dev->currentmode = INDIO_DIRECT_MODE;
|
|
error_run_postdisable:
|
|
if (indio_dev->setup_ops->postdisable)
|
|
indio_dev->setup_ops->postdisable(indio_dev);
|
|
error_remove_inserted:
|
|
if (insert_buffer)
|
|
iio_buffer_deactivate(insert_buffer);
|
|
indio_dev->active_scan_mask = old_mask;
|
|
kfree(compound_mask);
|
|
return ret;
|
|
}
|
|
|
|
int iio_update_buffers(struct iio_dev *indio_dev,
|
|
struct iio_buffer *insert_buffer,
|
|
struct iio_buffer *remove_buffer)
|
|
{
|
|
int ret;
|
|
|
|
if (insert_buffer == remove_buffer)
|
|
return 0;
|
|
|
|
mutex_lock(&indio_dev->info_exist_lock);
|
|
mutex_lock(&indio_dev->mlock);
|
|
|
|
if (insert_buffer && iio_buffer_is_active(insert_buffer))
|
|
insert_buffer = NULL;
|
|
|
|
if (remove_buffer && !iio_buffer_is_active(remove_buffer))
|
|
remove_buffer = NULL;
|
|
|
|
if (!insert_buffer && !remove_buffer) {
|
|
ret = 0;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (indio_dev->info == NULL) {
|
|
ret = -ENODEV;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&indio_dev->mlock);
|
|
mutex_unlock(&indio_dev->info_exist_lock);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_update_buffers);
|
|
|
|
static ssize_t iio_buffer_store_enable(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf,
|
|
size_t len)
|
|
{
|
|
int ret;
|
|
bool requested_state;
|
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
|
bool inlist;
|
|
|
|
ret = strtobool(buf, &requested_state);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
mutex_lock(&indio_dev->mlock);
|
|
|
|
/* Find out if it is in the list */
|
|
inlist = iio_buffer_is_active(indio_dev->buffer);
|
|
/* Already in desired state */
|
|
if (inlist == requested_state)
|
|
goto done;
|
|
|
|
if (requested_state)
|
|
ret = __iio_update_buffers(indio_dev,
|
|
indio_dev->buffer, NULL);
|
|
else
|
|
ret = __iio_update_buffers(indio_dev,
|
|
NULL, indio_dev->buffer);
|
|
|
|
if (ret < 0)
|
|
goto done;
|
|
done:
|
|
mutex_unlock(&indio_dev->mlock);
|
|
return (ret < 0) ? ret : len;
|
|
}
|
|
|
|
static const char * const iio_scan_elements_group_name = "scan_elements";
|
|
|
|
static ssize_t iio_buffer_show_watermark(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
|
struct iio_buffer *buffer = indio_dev->buffer;
|
|
|
|
return sprintf(buf, "%u\n", buffer->watermark);
|
|
}
|
|
|
|
static ssize_t iio_buffer_store_watermark(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf,
|
|
size_t len)
|
|
{
|
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
|
struct iio_buffer *buffer = indio_dev->buffer;
|
|
unsigned int val;
|
|
int ret;
|
|
|
|
ret = kstrtouint(buf, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
if (!val)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&indio_dev->mlock);
|
|
|
|
if (val > buffer->length) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (iio_buffer_is_active(indio_dev->buffer)) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
buffer->watermark = val;
|
|
|
|
if (indio_dev->info->hwfifo_set_watermark)
|
|
indio_dev->info->hwfifo_set_watermark(indio_dev, val);
|
|
out:
|
|
mutex_unlock(&indio_dev->mlock);
|
|
|
|
return ret ? ret : len;
|
|
}
|
|
|
|
static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length,
|
|
iio_buffer_write_length);
|
|
static struct device_attribute dev_attr_length_ro = __ATTR(length,
|
|
S_IRUGO, iio_buffer_read_length, NULL);
|
|
static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
|
|
iio_buffer_show_enable, iio_buffer_store_enable);
|
|
static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR,
|
|
iio_buffer_show_watermark, iio_buffer_store_watermark);
|
|
|
|
static struct attribute *iio_buffer_attrs[] = {
|
|
&dev_attr_length.attr,
|
|
&dev_attr_enable.attr,
|
|
&dev_attr_watermark.attr,
|
|
};
|
|
|
|
int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
|
|
{
|
|
struct iio_dev_attr *p;
|
|
struct attribute **attr;
|
|
struct iio_buffer *buffer = indio_dev->buffer;
|
|
int ret, i, attrn, attrcount, attrcount_orig = 0;
|
|
const struct iio_chan_spec *channels;
|
|
|
|
if (!buffer)
|
|
return 0;
|
|
|
|
attrcount = 0;
|
|
if (buffer->attrs) {
|
|
while (buffer->attrs[attrcount] != NULL)
|
|
attrcount++;
|
|
}
|
|
|
|
attr = kcalloc(attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1,
|
|
sizeof(struct attribute *), GFP_KERNEL);
|
|
if (!attr)
|
|
return -ENOMEM;
|
|
|
|
memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs));
|
|
if (!buffer->access->set_length)
|
|
attr[0] = &dev_attr_length_ro.attr;
|
|
|
|
if (buffer->attrs)
|
|
memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs,
|
|
sizeof(struct attribute *) * attrcount);
|
|
|
|
attr[attrcount + ARRAY_SIZE(iio_buffer_attrs)] = NULL;
|
|
|
|
buffer->buffer_group.name = "buffer";
|
|
buffer->buffer_group.attrs = attr;
|
|
|
|
indio_dev->groups[indio_dev->groupcounter++] = &buffer->buffer_group;
|
|
|
|
if (buffer->scan_el_attrs != NULL) {
|
|
attr = buffer->scan_el_attrs->attrs;
|
|
while (*attr++ != NULL)
|
|
attrcount_orig++;
|
|
}
|
|
attrcount = attrcount_orig;
|
|
INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list);
|
|
channels = indio_dev->channels;
|
|
if (channels) {
|
|
/* new magic */
|
|
for (i = 0; i < indio_dev->num_channels; i++) {
|
|
if (channels[i].scan_index < 0)
|
|
continue;
|
|
|
|
/* Establish necessary mask length */
|
|
if (channels[i].scan_index >
|
|
(int)indio_dev->masklength - 1)
|
|
indio_dev->masklength
|
|
= channels[i].scan_index + 1;
|
|
|
|
ret = iio_buffer_add_channel_sysfs(indio_dev,
|
|
&channels[i]);
|
|
if (ret < 0)
|
|
goto error_cleanup_dynamic;
|
|
attrcount += ret;
|
|
if (channels[i].type == IIO_TIMESTAMP)
|
|
indio_dev->scan_index_timestamp =
|
|
channels[i].scan_index;
|
|
}
|
|
if (indio_dev->masklength && buffer->scan_mask == NULL) {
|
|
buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
|
|
sizeof(*buffer->scan_mask),
|
|
GFP_KERNEL);
|
|
if (buffer->scan_mask == NULL) {
|
|
ret = -ENOMEM;
|
|
goto error_cleanup_dynamic;
|
|
}
|
|
}
|
|
}
|
|
|
|
buffer->scan_el_group.name = iio_scan_elements_group_name;
|
|
|
|
buffer->scan_el_group.attrs = kcalloc(attrcount + 1,
|
|
sizeof(buffer->scan_el_group.attrs[0]),
|
|
GFP_KERNEL);
|
|
if (buffer->scan_el_group.attrs == NULL) {
|
|
ret = -ENOMEM;
|
|
goto error_free_scan_mask;
|
|
}
|
|
if (buffer->scan_el_attrs)
|
|
memcpy(buffer->scan_el_group.attrs, buffer->scan_el_attrs,
|
|
sizeof(buffer->scan_el_group.attrs[0])*attrcount_orig);
|
|
attrn = attrcount_orig;
|
|
|
|
list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
|
|
buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;
|
|
indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group;
|
|
|
|
return 0;
|
|
|
|
error_free_scan_mask:
|
|
kfree(buffer->scan_mask);
|
|
error_cleanup_dynamic:
|
|
iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
|
|
kfree(indio_dev->buffer->buffer_group.attrs);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev)
|
|
{
|
|
if (!indio_dev->buffer)
|
|
return;
|
|
|
|
kfree(indio_dev->buffer->scan_mask);
|
|
kfree(indio_dev->buffer->buffer_group.attrs);
|
|
kfree(indio_dev->buffer->scan_el_group.attrs);
|
|
iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list);
|
|
}
|
|
|
|
/**
|
|
* iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
|
|
* @indio_dev: the iio device
|
|
* @mask: scan mask to be checked
|
|
*
|
|
* Return true if exactly one bit is set in the scan mask, false otherwise. It
|
|
* can be used for devices where only one channel can be active for sampling at
|
|
* a time.
|
|
*/
|
|
bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
|
|
const unsigned long *mask)
|
|
{
|
|
return bitmap_weight(mask, indio_dev->masklength) == 1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot);
|
|
|
|
int iio_scan_mask_query(struct iio_dev *indio_dev,
|
|
struct iio_buffer *buffer, int bit)
|
|
{
|
|
if (bit > indio_dev->masklength)
|
|
return -EINVAL;
|
|
|
|
if (!buffer->scan_mask)
|
|
return 0;
|
|
|
|
/* Ensure return value is 0 or 1. */
|
|
return !!test_bit(bit, buffer->scan_mask);
|
|
};
|
|
EXPORT_SYMBOL_GPL(iio_scan_mask_query);
|
|
|
|
/**
|
|
* struct iio_demux_table() - table describing demux memcpy ops
|
|
* @from: index to copy from
|
|
* @to: index to copy to
|
|
* @length: how many bytes to copy
|
|
* @l: list head used for management
|
|
*/
|
|
struct iio_demux_table {
|
|
unsigned from;
|
|
unsigned to;
|
|
unsigned length;
|
|
struct list_head l;
|
|
};
|
|
|
|
static const void *iio_demux(struct iio_buffer *buffer,
|
|
const void *datain)
|
|
{
|
|
struct iio_demux_table *t;
|
|
|
|
if (list_empty(&buffer->demux_list))
|
|
return datain;
|
|
list_for_each_entry(t, &buffer->demux_list, l)
|
|
memcpy(buffer->demux_bounce + t->to,
|
|
datain + t->from, t->length);
|
|
|
|
return buffer->demux_bounce;
|
|
}
|
|
|
|
static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
|
|
{
|
|
const void *dataout = iio_demux(buffer, data);
|
|
int ret;
|
|
|
|
ret = buffer->access->store_to(buffer, dataout);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* We can't just test for watermark to decide if we wake the poll queue
|
|
* because read may request less samples than the watermark.
|
|
*/
|
|
wake_up_interruptible_poll(&buffer->pollq, POLLIN | POLLRDNORM);
|
|
return 0;
|
|
}
|
|
|
|
static void iio_buffer_demux_free(struct iio_buffer *buffer)
|
|
{
|
|
struct iio_demux_table *p, *q;
|
|
list_for_each_entry_safe(p, q, &buffer->demux_list, l) {
|
|
list_del(&p->l);
|
|
kfree(p);
|
|
}
|
|
}
|
|
|
|
|
|
int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
|
|
{
|
|
int ret;
|
|
struct iio_buffer *buf;
|
|
|
|
list_for_each_entry(buf, &indio_dev->buffer_list, buffer_list) {
|
|
ret = iio_push_to_buffer(buf, data);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_push_to_buffers);
|
|
|
|
static int iio_buffer_add_demux(struct iio_buffer *buffer,
|
|
struct iio_demux_table **p, unsigned int in_loc, unsigned int out_loc,
|
|
unsigned int length)
|
|
{
|
|
|
|
if (*p && (*p)->from + (*p)->length == in_loc &&
|
|
(*p)->to + (*p)->length == out_loc) {
|
|
(*p)->length += length;
|
|
} else {
|
|
*p = kmalloc(sizeof(**p), GFP_KERNEL);
|
|
if (*p == NULL)
|
|
return -ENOMEM;
|
|
(*p)->from = in_loc;
|
|
(*p)->to = out_loc;
|
|
(*p)->length = length;
|
|
list_add_tail(&(*p)->l, &buffer->demux_list);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int iio_buffer_update_demux(struct iio_dev *indio_dev,
|
|
struct iio_buffer *buffer)
|
|
{
|
|
const struct iio_chan_spec *ch;
|
|
int ret, in_ind = -1, out_ind, length;
|
|
unsigned in_loc = 0, out_loc = 0;
|
|
struct iio_demux_table *p = NULL;
|
|
|
|
/* Clear out any old demux */
|
|
iio_buffer_demux_free(buffer);
|
|
kfree(buffer->demux_bounce);
|
|
buffer->demux_bounce = NULL;
|
|
|
|
/* First work out which scan mode we will actually have */
|
|
if (bitmap_equal(indio_dev->active_scan_mask,
|
|
buffer->scan_mask,
|
|
indio_dev->masklength))
|
|
return 0;
|
|
|
|
/* Now we have the two masks, work from least sig and build up sizes */
|
|
for_each_set_bit(out_ind,
|
|
buffer->scan_mask,
|
|
indio_dev->masklength) {
|
|
in_ind = find_next_bit(indio_dev->active_scan_mask,
|
|
indio_dev->masklength,
|
|
in_ind + 1);
|
|
while (in_ind != out_ind) {
|
|
in_ind = find_next_bit(indio_dev->active_scan_mask,
|
|
indio_dev->masklength,
|
|
in_ind + 1);
|
|
ch = iio_find_channel_from_si(indio_dev, in_ind);
|
|
if (ch->scan_type.repeat > 1)
|
|
length = ch->scan_type.storagebits / 8 *
|
|
ch->scan_type.repeat;
|
|
else
|
|
length = ch->scan_type.storagebits / 8;
|
|
/* Make sure we are aligned */
|
|
in_loc = roundup(in_loc, length) + length;
|
|
}
|
|
ch = iio_find_channel_from_si(indio_dev, in_ind);
|
|
if (ch->scan_type.repeat > 1)
|
|
length = ch->scan_type.storagebits / 8 *
|
|
ch->scan_type.repeat;
|
|
else
|
|
length = ch->scan_type.storagebits / 8;
|
|
out_loc = roundup(out_loc, length);
|
|
in_loc = roundup(in_loc, length);
|
|
ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
|
|
if (ret)
|
|
goto error_clear_mux_table;
|
|
out_loc += length;
|
|
in_loc += length;
|
|
}
|
|
/* Relies on scan_timestamp being last */
|
|
if (buffer->scan_timestamp) {
|
|
ch = iio_find_channel_from_si(indio_dev,
|
|
indio_dev->scan_index_timestamp);
|
|
if (ch->scan_type.repeat > 1)
|
|
length = ch->scan_type.storagebits / 8 *
|
|
ch->scan_type.repeat;
|
|
else
|
|
length = ch->scan_type.storagebits / 8;
|
|
out_loc = roundup(out_loc, length);
|
|
in_loc = roundup(in_loc, length);
|
|
ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
|
|
if (ret)
|
|
goto error_clear_mux_table;
|
|
out_loc += length;
|
|
in_loc += length;
|
|
}
|
|
buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL);
|
|
if (buffer->demux_bounce == NULL) {
|
|
ret = -ENOMEM;
|
|
goto error_clear_mux_table;
|
|
}
|
|
return 0;
|
|
|
|
error_clear_mux_table:
|
|
iio_buffer_demux_free(buffer);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int iio_update_demux(struct iio_dev *indio_dev)
|
|
{
|
|
struct iio_buffer *buffer;
|
|
int ret;
|
|
|
|
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
|
|
ret = iio_buffer_update_demux(indio_dev, buffer);
|
|
if (ret < 0)
|
|
goto error_clear_mux_table;
|
|
}
|
|
return 0;
|
|
|
|
error_clear_mux_table:
|
|
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list)
|
|
iio_buffer_demux_free(buffer);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_update_demux);
|
|
|
|
/**
|
|
* iio_buffer_release() - Free a buffer's resources
|
|
* @ref: Pointer to the kref embedded in the iio_buffer struct
|
|
*
|
|
* This function is called when the last reference to the buffer has been
|
|
* dropped. It will typically free all resources allocated by the buffer. Do not
|
|
* call this function manually, always use iio_buffer_put() when done using a
|
|
* buffer.
|
|
*/
|
|
static void iio_buffer_release(struct kref *ref)
|
|
{
|
|
struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref);
|
|
|
|
buffer->access->release(buffer);
|
|
}
|
|
|
|
/**
|
|
* iio_buffer_get() - Grab a reference to the buffer
|
|
* @buffer: The buffer to grab a reference for, may be NULL
|
|
*
|
|
* Returns the pointer to the buffer that was passed into the function.
|
|
*/
|
|
struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer)
|
|
{
|
|
if (buffer)
|
|
kref_get(&buffer->ref);
|
|
|
|
return buffer;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_buffer_get);
|
|
|
|
/**
|
|
* iio_buffer_put() - Release the reference to the buffer
|
|
* @buffer: The buffer to release the reference for, may be NULL
|
|
*/
|
|
void iio_buffer_put(struct iio_buffer *buffer)
|
|
{
|
|
if (buffer)
|
|
kref_put(&buffer->ref, iio_buffer_release);
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_buffer_put);
|