OpenCloudOS-Kernel/drivers/iio/industrialio-buffer.c

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// SPDX-License-Identifier: GPL-2.0-only
/* The industrial I/O core
*
* Copyright (c) 2008 Jonathan Cameron
*
* Handling of buffer allocation / resizing.
*
* Things to look at here.
* - Better memory allocation techniques?
* - Alternative access techniques?
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/cdev.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/sched/signal.h>
#include <linux/iio/iio.h>
#include "iio_core.h"
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/buffer_impl.h>
static const char * const iio_endian_prefix[] = {
[IIO_BE] = "be",
[IIO_LE] = "le",
};
static bool iio_buffer_is_active(struct iio_buffer *buf)
{
return !list_empty(&buf->buffer_list);
}
static size_t iio_buffer_data_available(struct iio_buffer *buf)
{
return buf->access->data_available(buf);
}
iio: add support for hardware fifo 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>
2015-03-23 02:33:39 +08:00
static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev,
struct iio_buffer *buf, size_t required)
{
if (!indio_dev->info->hwfifo_flush_to_buffer)
return -ENODEV;
return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required);
}
static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
iio: add support for hardware fifo 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>
2015-03-23 02:33:39 +08:00
size_t to_wait, int to_flush)
{
iio: add support for hardware fifo 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>
2015-03-23 02:33:39 +08:00
size_t avail;
int flushed = 0;
/* wakeup if the device was unregistered */
if (!indio_dev->info)
return true;
/* drain the buffer if it was disabled */
iio: add support for hardware fifo 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>
2015-03-23 02:33:39 +08:00
if (!iio_buffer_is_active(buf)) {
to_wait = min_t(size_t, to_wait, 1);
iio: add support for hardware fifo 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>
2015-03-23 02:33:39 +08:00
to_flush = 0;
}
avail = iio_buffer_data_available(buf);
iio: add support for hardware fifo 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>
2015-03-23 02:33:39 +08:00
if (avail >= to_wait) {
/* force a flush for non-blocking reads */
if (!to_wait && avail < to_flush)
iio_buffer_flush_hwfifo(indio_dev, buf,
to_flush - avail);
iio: add support for hardware fifo 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>
2015-03-23 02:33:39 +08:00
return true;
}
if (to_flush)
flushed = iio_buffer_flush_hwfifo(indio_dev, buf,
to_wait - avail);
if (flushed <= 0)
return false;
if (avail + flushed >= to_wait)
return true;
return false;
}
/**
* iio_buffer_read_outer() - chrdev read for buffer access
* @filp: File structure pointer for the char device
* @buf: Destination buffer for iio buffer read
* @n: First n bytes to read
* @f_ps: Long offset provided by the user as a seek position
*
* This function relies on all buffer implementations having an
* iio_buffer as their first element.
*
* Return: negative values corresponding to error codes or ret != 0
* for ending the reading activity
**/
ssize_t iio_buffer_read_outer(struct file *filp, char __user *buf,
size_t n, loff_t *f_ps)
{
struct iio_dev *indio_dev = filp->private_data;
struct iio_buffer *rb = indio_dev->buffer;
2016-08-09 08:19:38 +08:00
DEFINE_WAIT_FUNC(wait, woken_wake_function);
size_t datum_size;
size_t to_wait;
int ret = 0;
if (!indio_dev->info)
return -ENODEV;
if (!rb || !rb->access->read)
return -EINVAL;
datum_size = rb->bytes_per_datum;
/*
* If datum_size is 0 there will never be anything to read from the
* buffer, so signal end of file now.
*/
if (!datum_size)
return 0;
if (filp->f_flags & O_NONBLOCK)
to_wait = 0;
else
to_wait = min_t(size_t, n / datum_size, rb->watermark);
2016-08-09 08:19:38 +08:00
add_wait_queue(&rb->pollq, &wait);
do {
2016-08-09 08:19:38 +08:00
if (!indio_dev->info) {
ret = -ENODEV;
break;
}
if (!iio_buffer_ready(indio_dev, rb, to_wait, n / datum_size)) {
if (signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
wait_woken(&wait, TASK_INTERRUPTIBLE,
MAX_SCHEDULE_TIMEOUT);
continue;
}
ret = rb->access->read(rb, n, buf);
if (ret == 0 && (filp->f_flags & O_NONBLOCK))
ret = -EAGAIN;
} while (ret == 0);
2016-08-09 08:19:38 +08:00
remove_wait_queue(&rb->pollq, &wait);
return ret;
}
/**
* iio_buffer_poll() - poll the buffer to find out if it has data
* @filp: File structure pointer for device access
* @wait: Poll table structure pointer for which the driver adds
* a wait queue
*
* Return: (EPOLLIN | EPOLLRDNORM) if data is available for reading
* or 0 for other cases
*/
__poll_t iio_buffer_poll(struct file *filp,
struct poll_table_struct *wait)
{
struct iio_dev *indio_dev = filp->private_data;
struct iio_buffer *rb = indio_dev->buffer;
if (!indio_dev->info || rb == NULL)
return 0;
poll_wait(filp, &rb->pollq, wait);
iio: add support for hardware fifo 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>
2015-03-23 02:33:39 +08:00
if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
return EPOLLIN | EPOLLRDNORM;
return 0;
}
/**
* iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
* @indio_dev: The IIO device
*
* Wakes up the event waitqueue used for poll(). Should usually
* be called when the device is unregistered.
*/
void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
{
if (!indio_dev->buffer)
return;
wake_up(&indio_dev->buffer->pollq);
}
void iio_buffer_init(struct iio_buffer *buffer)
{
INIT_LIST_HEAD(&buffer->demux_list);
INIT_LIST_HEAD(&buffer->buffer_list);
init_waitqueue_head(&buffer->pollq);
kref_init(&buffer->ref);
if (!buffer->watermark)
buffer->watermark = 1;
}
EXPORT_SYMBOL(iio_buffer_init);
/**
* iio_buffer_set_attrs - Set buffer specific attributes
* @buffer: The buffer for which we are setting attributes
* @attrs: Pointer to a null terminated list of pointers to attributes
*/
void iio_buffer_set_attrs(struct iio_buffer *buffer,
const struct attribute **attrs)
{
buffer->attrs = attrs;
}
EXPORT_SYMBOL_GPL(iio_buffer_set_attrs);
static ssize_t iio_show_scan_index(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
}
static ssize_t iio_show_fixed_type(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
u8 type = this_attr->c->scan_type.endianness;
if (type == IIO_CPU) {
#ifdef __LITTLE_ENDIAN
type = IIO_LE;
#else
type = IIO_BE;
#endif
}
if (this_attr->c->scan_type.repeat > 1)
return sprintf(buf, "%s:%c%d/%dX%d>>%u\n",
iio_endian_prefix[type],
this_attr->c->scan_type.sign,
this_attr->c->scan_type.realbits,
this_attr->c->scan_type.storagebits,
this_attr->c->scan_type.repeat,
this_attr->c->scan_type.shift);
else
return sprintf(buf, "%s:%c%d/%d>>%u\n",
iio_endian_prefix[type],
this_attr->c->scan_type.sign,
this_attr->c->scan_type.realbits,
this_attr->c->scan_type.storagebits,
this_attr->c->scan_type.shift);
}
static ssize_t iio_scan_el_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
/* Ensure ret is 0 or 1. */
ret = !!test_bit(to_iio_dev_attr(attr)->address,
indio_dev->buffer->scan_mask);
return sprintf(buf, "%d\n", ret);
}
/* Note NULL used as error indicator as it doesn't make sense. */
static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
unsigned int masklength,
const unsigned long *mask,
bool strict)
{
if (bitmap_empty(mask, masklength))
return NULL;
while (*av_masks) {
if (strict) {
if (bitmap_equal(mask, av_masks, masklength))
return av_masks;
} else {
if (bitmap_subset(mask, av_masks, masklength))
return av_masks;
}
av_masks += BITS_TO_LONGS(masklength);
}
return NULL;
}
static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
const unsigned long *mask)
{
if (!indio_dev->setup_ops->validate_scan_mask)
return true;
return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
}
/**
* iio_scan_mask_set() - set particular bit in the scan mask
* @indio_dev: the iio device
* @buffer: the buffer whose scan mask we are interested in
* @bit: the bit to be set.
*
* Note that at this point we have no way of knowing what other
* buffers might request, hence this code only verifies that the
* individual buffers request is plausible.
*/
static int iio_scan_mask_set(struct iio_dev *indio_dev,
struct iio_buffer *buffer, int bit)
{
const unsigned long *mask;
unsigned long *trialmask;
trialmask = bitmap_zalloc(indio_dev->masklength, GFP_KERNEL);
if (trialmask == NULL)
return -ENOMEM;
if (!indio_dev->masklength) {
WARN(1, "Trying to set scanmask prior to registering buffer\n");
goto err_invalid_mask;
}
bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
set_bit(bit, trialmask);
if (!iio_validate_scan_mask(indio_dev, trialmask))
goto err_invalid_mask;
if (indio_dev->available_scan_masks) {
mask = iio_scan_mask_match(indio_dev->available_scan_masks,
indio_dev->masklength,
trialmask, false);
if (!mask)
goto err_invalid_mask;
}
bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
bitmap_free(trialmask);
return 0;
err_invalid_mask:
bitmap_free(trialmask);
return -EINVAL;
}
static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
{
clear_bit(bit, buffer->scan_mask);
return 0;
}
static 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);
};
static ssize_t iio_scan_el_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
bool state;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer;
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
ret = strtobool(buf, &state);
if (ret < 0)
return ret;
mutex_lock(&indio_dev->mlock);
if (iio_buffer_is_active(indio_dev->buffer)) {
ret = -EBUSY;
goto error_ret;
}
ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
if (ret < 0)
goto error_ret;
if (!state && ret) {
ret = iio_scan_mask_clear(buffer, this_attr->address);
if (ret)
goto error_ret;
} else if (state && !ret) {
ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
if (ret)
goto error_ret;
}
error_ret:
mutex_unlock(&indio_dev->mlock);
return ret < 0 ? ret : len;
}
static ssize_t iio_scan_el_ts_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
return sprintf(buf, "%d\n", indio_dev->buffer->scan_timestamp);
}
static ssize_t iio_scan_el_ts_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
bool state;
ret = strtobool(buf, &state);
if (ret < 0)
return ret;
mutex_lock(&indio_dev->mlock);
if (iio_buffer_is_active(indio_dev->buffer)) {
ret = -EBUSY;
goto error_ret;
}
indio_dev->buffer->scan_timestamp = state;
error_ret:
mutex_unlock(&indio_dev->mlock);
return ret ? ret : len;
}
static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
int ret, attrcount = 0;
struct iio_buffer *buffer = indio_dev->buffer;
ret = __iio_add_chan_devattr("index",
chan,
&iio_show_scan_index,
NULL,
0,
IIO_SEPARATE,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
if (ret)
return ret;
attrcount++;
ret = __iio_add_chan_devattr("type",
chan,
&iio_show_fixed_type,
NULL,
0,
0,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
if (ret)
return ret;
attrcount++;
if (chan->type != IIO_TIMESTAMP)
ret = __iio_add_chan_devattr("en",
chan,
&iio_scan_el_show,
&iio_scan_el_store,
chan->scan_index,
0,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
else
ret = __iio_add_chan_devattr("en",
chan,
&iio_scan_el_ts_show,
&iio_scan_el_ts_store,
chan->scan_index,
0,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
if (ret)
return ret;
attrcount++;
ret = attrcount;
return ret;
}
static ssize_t iio_buffer_read_length(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, "%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;
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 unsigned int iio_storage_bytes_for_si(struct iio_dev *indio_dev,
unsigned int scan_index)
{
const struct iio_chan_spec *ch;
unsigned int bytes;
ch = iio_find_channel_from_si(indio_dev, scan_index);
bytes = ch->scan_type.storagebits / 8;
if (ch->scan_type.repeat > 1)
bytes *= ch->scan_type.repeat;
return bytes;
}
static unsigned int iio_storage_bytes_for_timestamp(struct iio_dev *indio_dev)
{
return iio_storage_bytes_for_si(indio_dev,
indio_dev->scan_index_timestamp);
}
static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
const unsigned long *mask, bool timestamp)
{
unsigned bytes = 0;
int length, i, largest = 0;
/* How much space will the demuxed element take? */
for_each_set_bit(i, mask,
indio_dev->masklength) {
length = iio_storage_bytes_for_si(indio_dev, i);
bytes = ALIGN(bytes, length);
bytes += length;
largest = max(largest, length);
}
if (timestamp) {
length = iio_storage_bytes_for_timestamp(indio_dev);
bytes = ALIGN(bytes, length);
bytes += length;
largest = max(largest, length);
}
bytes = ALIGN(bytes, largest);
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);
}
static void iio_buffer_deactivate_all(struct iio_dev *indio_dev)
{
struct iio_buffer *buffer, *_buffer;
list_for_each_entry_safe(buffer, _buffer,
&indio_dev->buffer_list, buffer_list)
iio_buffer_deactivate(buffer);
}
static int iio_buffer_enable(struct iio_buffer *buffer,
struct iio_dev *indio_dev)
{
if (!buffer->access->enable)
return 0;
return buffer->access->enable(buffer, indio_dev);
}
static int iio_buffer_disable(struct iio_buffer *buffer,
struct iio_dev *indio_dev)
{
if (!buffer->access->disable)
return 0;
return buffer->access->disable(buffer, indio_dev);
}
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_buffer_request_update(struct iio_dev *indio_dev,
struct iio_buffer *buffer)
{
int ret;
iio_buffer_update_bytes_per_datum(indio_dev, buffer);
if (buffer->access->request_update) {
ret = buffer->access->request_update(buffer);
if (ret) {
dev_dbg(&indio_dev->dev,
"Buffer not started: buffer parameter update failed (%d)\n",
ret);
return ret;
}
}
return 0;
}
static void iio_free_scan_mask(struct iio_dev *indio_dev,
const unsigned long *mask)
{
/* If the mask is dynamically allocated free it, otherwise do nothing */
if (!indio_dev->available_scan_masks)
bitmap_free(mask);
}
struct iio_device_config {
unsigned int mode;
unsigned int watermark;
const unsigned long *scan_mask;
unsigned int scan_bytes;
bool scan_timestamp;
};
static int iio_verify_update(struct iio_dev *indio_dev,
struct iio_buffer *insert_buffer, struct iio_buffer *remove_buffer,
struct iio_device_config *config)
{
unsigned long *compound_mask;
const unsigned long *scan_mask;
bool strict_scanmask = false;
struct iio_buffer *buffer;
bool scan_timestamp;
unsigned int modes;
memset(config, 0, sizeof(*config));
config->watermark = ~0;
/*
* If there is just one buffer and we are removing it there is nothing
* to verify.
*/
if (remove_buffer && !insert_buffer &&
list_is_singular(&indio_dev->buffer_list))
return 0;
modes = indio_dev->modes;
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
if (buffer == remove_buffer)
continue;
modes &= buffer->access->modes;
config->watermark = min(config->watermark, buffer->watermark);
}
if (insert_buffer) {
modes &= insert_buffer->access->modes;
config->watermark = min(config->watermark,
insert_buffer->watermark);
}
/* Definitely possible for devices to support both of these. */
if ((modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) {
config->mode = INDIO_BUFFER_TRIGGERED;
} else if (modes & INDIO_BUFFER_HARDWARE) {
/*
* Keep things simple for now and only allow a single buffer to
* be connected in hardware mode.
*/
if (insert_buffer && !list_empty(&indio_dev->buffer_list))
return -EINVAL;
config->mode = INDIO_BUFFER_HARDWARE;
strict_scanmask = true;
} else if (modes & INDIO_BUFFER_SOFTWARE) {
config->mode = INDIO_BUFFER_SOFTWARE;
} else {
/* Can only occur on first buffer */
if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
dev_dbg(&indio_dev->dev, "Buffer not started: no trigger\n");
return -EINVAL;
}
/* What scan mask do we actually have? */
compound_mask = bitmap_zalloc(indio_dev->masklength, GFP_KERNEL);
if (compound_mask == NULL)
return -ENOMEM;
scan_timestamp = false;
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
if (buffer == remove_buffer)
continue;
bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
indio_dev->masklength);
scan_timestamp |= buffer->scan_timestamp;
}
if (insert_buffer) {
bitmap_or(compound_mask, compound_mask,
insert_buffer->scan_mask, indio_dev->masklength);
scan_timestamp |= insert_buffer->scan_timestamp;
}
if (indio_dev->available_scan_masks) {
scan_mask = iio_scan_mask_match(indio_dev->available_scan_masks,
indio_dev->masklength,
compound_mask,
strict_scanmask);
bitmap_free(compound_mask);
if (scan_mask == NULL)
return -EINVAL;
} else {
scan_mask = compound_mask;
}
config->scan_bytes = iio_compute_scan_bytes(indio_dev,
scan_mask, scan_timestamp);
config->scan_mask = scan_mask;
config->scan_timestamp = scan_timestamp;
return 0;
}
/**
* 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 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);
}
}
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)
{
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);
length = iio_storage_bytes_for_si(indio_dev, in_ind);
/* Make sure we are aligned */
in_loc = roundup(in_loc, length) + length;
}
length = iio_storage_bytes_for_si(indio_dev, in_ind);
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) {
length = iio_storage_bytes_for_timestamp(indio_dev);
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;
}
static 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;
}
static int iio_enable_buffers(struct iio_dev *indio_dev,
struct iio_device_config *config)
{
struct iio_buffer *buffer;
int ret;
indio_dev->active_scan_mask = config->scan_mask;
indio_dev->scan_timestamp = config->scan_timestamp;
indio_dev->scan_bytes = config->scan_bytes;
iio_update_demux(indio_dev);
/* Wind up again */
if (indio_dev->setup_ops->preenable) {
ret = indio_dev->setup_ops->preenable(indio_dev);
if (ret) {
dev_dbg(&indio_dev->dev,
"Buffer not started: buffer preenable failed (%d)\n", ret);
goto err_undo_config;
}
}
if (indio_dev->info->update_scan_mode) {
ret = indio_dev->info
->update_scan_mode(indio_dev,
indio_dev->active_scan_mask);
if (ret < 0) {
dev_dbg(&indio_dev->dev,
"Buffer not started: update scan mode failed (%d)\n",
ret);
goto err_run_postdisable;
}
}
if (indio_dev->info->hwfifo_set_watermark)
indio_dev->info->hwfifo_set_watermark(indio_dev,
config->watermark);
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
ret = iio_buffer_enable(buffer, indio_dev);
if (ret)
goto err_disable_buffers;
}
indio_dev->currentmode = config->mode;
if (indio_dev->setup_ops->postenable) {
ret = indio_dev->setup_ops->postenable(indio_dev);
if (ret) {
dev_dbg(&indio_dev->dev,
"Buffer not started: postenable failed (%d)\n", ret);
goto err_disable_buffers;
}
}
return 0;
err_disable_buffers:
list_for_each_entry_continue_reverse(buffer, &indio_dev->buffer_list,
buffer_list)
iio_buffer_disable(buffer, indio_dev);
err_run_postdisable:
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->setup_ops->postdisable)
indio_dev->setup_ops->postdisable(indio_dev);
err_undo_config:
indio_dev->active_scan_mask = NULL;
return ret;
}
static int iio_disable_buffers(struct iio_dev *indio_dev)
{
struct iio_buffer *buffer;
int ret = 0;
int ret2;
/* Wind down existing buffers - iff there are any */
if (list_empty(&indio_dev->buffer_list))
return 0;
/*
* If things go wrong at some step in disable we still need to continue
* to perform the other steps, otherwise we leave the device in a
* inconsistent state. We return the error code for the first error we
* encountered.
*/
if (indio_dev->setup_ops->predisable) {
ret2 = indio_dev->setup_ops->predisable(indio_dev);
if (ret2 && !ret)
ret = ret2;
}
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
ret2 = iio_buffer_disable(buffer, indio_dev);
if (ret2 && !ret)
ret = ret2;
}
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->setup_ops->postdisable) {
ret2 = indio_dev->setup_ops->postdisable(indio_dev);
if (ret2 && !ret)
ret = ret2;
}
iio_free_scan_mask(indio_dev, indio_dev->active_scan_mask);
indio_dev->active_scan_mask = NULL;
return ret;
}
static int __iio_update_buffers(struct iio_dev *indio_dev,
struct iio_buffer *insert_buffer,
struct iio_buffer *remove_buffer)
{
struct iio_device_config new_config;
int ret;
ret = iio_verify_update(indio_dev, insert_buffer, remove_buffer,
&new_config);
if (ret)
return ret;
if (insert_buffer) {
ret = iio_buffer_request_update(indio_dev, insert_buffer);
if (ret)
goto err_free_config;
}
ret = iio_disable_buffers(indio_dev);
if (ret)
goto err_deactivate_all;
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))
return 0;
ret = iio_enable_buffers(indio_dev, &new_config);
if (ret)
goto err_deactivate_all;
return 0;
err_deactivate_all:
/*
* We've already verified that the config is valid earlier. If things go
* wrong in either enable or disable the most likely reason is an IO
* error from the device. In this case there is no good recovery
* strategy. Just make sure to disable everything and leave the device
* in a sane state. With a bit of luck the device might come back to
* life again later and userspace can try again.
*/
iio_buffer_deactivate_all(indio_dev);
err_free_config:
iio_free_scan_mask(indio_dev, new_config.scan_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);
void iio_disable_all_buffers(struct iio_dev *indio_dev)
{
iio_disable_buffers(indio_dev);
iio_buffer_deactivate_all(indio_dev);
}
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);
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;
out:
mutex_unlock(&indio_dev->mlock);
return ret ? ret : len;
}
static ssize_t iio_dma_show_data_available(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
size_t bytes;
bytes = iio_buffer_data_available(indio_dev->buffer);
return sprintf(buf, "%zu\n", bytes);
}
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 device_attribute dev_attr_watermark_ro = __ATTR(watermark,
S_IRUGO, iio_buffer_show_watermark, NULL);
static DEVICE_ATTR(data_available, S_IRUGO,
iio_dma_show_data_available, NULL);
static struct attribute *iio_buffer_attrs[] = {
&dev_attr_length.attr,
&dev_attr_enable.attr,
&dev_attr_watermark.attr,
&dev_attr_data_available.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;
channels = indio_dev->channels;
if (channels) {
int ml = indio_dev->masklength;
for (i = 0; i < indio_dev->num_channels; i++)
ml = max(ml, channels[i].scan_index + 1);
indio_dev->masklength = ml;
}
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->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK)
attr[2] = &dev_attr_watermark_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;
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 = bitmap_zalloc(indio_dev->masklength,
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:
bitmap_free(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;
bitmap_free(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);
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, EPOLLIN | EPOLLRDNORM);
return 0;
}
/**
* iio_push_to_buffers() - push to a registered buffer.
* @indio_dev: iio_dev structure for device.
* @data: Full scan.
*/
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);
/**
* 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);
/**
* iio_device_attach_buffer - Attach a buffer to a IIO device
* @indio_dev: The device the buffer should be attached to
* @buffer: The buffer to attach to the device
*
* This function attaches a buffer to a IIO device. The buffer stays attached to
* the device until the device is freed. The function should only be called at
* most once per device.
*/
void iio_device_attach_buffer(struct iio_dev *indio_dev,
struct iio_buffer *buffer)
{
indio_dev->buffer = iio_buffer_get(buffer);
}
EXPORT_SYMBOL_GPL(iio_device_attach_buffer);