drivers/iio/buffer/industrialio-triggered-buffer.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2  /*
   3  * Copyright (c) 2012 Analog Devices, Inc.
   4  *  Author: Lars-Peter Clausen <lars@metafoo.de>
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/export.h>
   9 #include <linux/module.h>
  10 #include <linux/iio/iio.h>
  11 #include <linux/iio/buffer.h>
  12 #include <linux/iio/buffer_impl.h>
  13 #include <linux/iio/kfifo_buf.h>
  14 #include <linux/iio/triggered_buffer.h>
  15 #include <linux/iio/trigger_consumer.h>
  16
  17 /**
  18  * iio_triggered_buffer_setup_ext() - Setup triggered buffer and pollfunc
  19  * @indio_dev:          IIO device structure
  20  * @h:                  Function which will be used as pollfunc top half
  21  * @thread:             Function which will be used as pollfunc bottom half
  22  * @direction:          Direction of the data stream (in/out).
  23  * @setup_ops:          Buffer setup functions to use for this device.
  24  *                      If NULL the default setup functions for triggered
  25  *                      buffers will be used.
  26  * @buffer_attrs:       Extra sysfs buffer attributes for this IIO buffer
  27  *
  28  * This function combines some common tasks which will normally be performed
  29  * when setting up a triggered buffer. It will allocate the buffer and the
  30  * pollfunc.
  31  *
  32  * Before calling this function the indio_dev structure should already be
  33  * completely initialized, but not yet registered. In practice this means that
  34  * this function should be called right before iio_device_register().
  35  *
  36  * To free the resources allocated by this function call
  37  * iio_triggered_buffer_cleanup().
  38  */
  39 int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
  40         irqreturn_t (*h)(int irq, void *p),
  41         irqreturn_t (*thread)(int irq, void *p),
  42         enum iio_buffer_direction direction,
  43         const struct iio_buffer_setup_ops *setup_ops,
  44         const struct iio_dev_attr **buffer_attrs)
  45 {
  46         struct iio_buffer *buffer;
  47         int ret;
  48
  49         buffer = iio_kfifo_allocate();
  50         if (!buffer) {
  51                 ret = -ENOMEM;
  52                 goto error_ret;
  53         }
  54
  55         indio_dev->pollfunc = iio_alloc_pollfunc(h,
  56                                                  thread,
  57                                                  IRQF_ONESHOT,
  58                                                  indio_dev,
  59                                                  "%s_consumer%d",
  60                                                  indio_dev->name,
  61                                                  iio_device_id(indio_dev));
  62         if (indio_dev->pollfunc == NULL) {
  63                 ret = -ENOMEM;
  64                 goto error_kfifo_free;
  65         }
  66
  67         /* Ring buffer functions - here trigger setup related */
  68         indio_dev->setup_ops = setup_ops;
  69
  70         /* Flag that polled ring buffering is possible */
  71         indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
  72
  73         buffer->direction = direction;
  74         buffer->attrs = buffer_attrs;
  75
  76         ret = iio_device_attach_buffer(indio_dev, buffer);
  77         if (ret < 0)
  78                 goto error_dealloc_pollfunc;
  79
  80         return 0;
  81
  82 error_dealloc_pollfunc:
  83         iio_dealloc_pollfunc(indio_dev->pollfunc);
  84 error_kfifo_free:
  85         iio_kfifo_free(buffer);
  86 error_ret:
  87         return ret;
  88 }
  89 EXPORT_SYMBOL(iio_triggered_buffer_setup_ext);
  90
  91 /**
  92  * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext()
  93  * @indio_dev: IIO device structure
  94  */
  95 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
  96 {
  97         iio_dealloc_pollfunc(indio_dev->pollfunc);
  98         iio_kfifo_free(indio_dev->buffer);
  99 }
 100 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
 101
 102 static void devm_iio_triggered_buffer_clean(void *indio_dev)
 103 {
 104         iio_triggered_buffer_cleanup(indio_dev);
 105 }
 106
 107 int devm_iio_triggered_buffer_setup_ext(struct device *dev,
 108                                         struct iio_dev *indio_dev,
 109                                         irqreturn_t (*h)(int irq, void *p),
 110                                         irqreturn_t (*thread)(int irq, void *p),
 111                                         enum iio_buffer_direction direction,
 112                                         const struct iio_buffer_setup_ops *ops,
 113                                         const struct iio_dev_attr **buffer_attrs)
 114 {
 115         int ret;
 116
 117         ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, direction,
 118                                              ops, buffer_attrs);
 119         if (ret)
 120                 return ret;
 121
 122         return devm_add_action_or_reset(dev, devm_iio_triggered_buffer_clean,
 123                                         indio_dev);
 124 }
 125 EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext);
 126
 127 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 128 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
 129 MODULE_LICENSE("GPL");