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  * @setup_ops:          Buffer setup functions to use for this device.
  23  *                      If NULL the default setup functions for triggered
  24  *                      buffers will be used.
  25  * @buffer_attrs:       Extra sysfs buffer attributes for this IIO buffer
  26  *
  27  * This function combines some common tasks which will normally be performed
  28  * when setting up a triggered buffer. It will allocate the buffer and the
  29  * pollfunc.
  30  *
  31  * Before calling this function the indio_dev structure should already be
  32  * completely initialized, but not yet registered. In practice this means that
  33  * this function should be called right before iio_device_register().
  34  *
  35  * To free the resources allocated by this function call
  36  * iio_triggered_buffer_cleanup().
  37  */
  38 int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
  39         irqreturn_t (*h)(int irq, void *p),
  40         irqreturn_t (*thread)(int irq, void *p),
  41         const struct iio_buffer_setup_ops *setup_ops,
  42         const struct attribute **buffer_attrs)
  43 {
  44         struct iio_buffer *buffer;
  45         int ret;
  46
  47         buffer = iio_kfifo_allocate();
  48         if (!buffer) {
  49                 ret = -ENOMEM;
  50                 goto error_ret;
  51         }
  52
  53         iio_device_attach_buffer(indio_dev, buffer);
  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                                                  indio_dev->id);
  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->attrs = buffer_attrs;
  74
  75         return 0;
  76
  77 error_kfifo_free:
  78         iio_kfifo_free(indio_dev->buffer);
  79 error_ret:
  80         return ret;
  81 }
  82 EXPORT_SYMBOL(iio_triggered_buffer_setup_ext);
  83
  84 /**
  85  * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext()
  86  * @indio_dev: IIO device structure
  87  */
  88 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
  89 {
  90         iio_dealloc_pollfunc(indio_dev->pollfunc);
  91         iio_kfifo_free(indio_dev->buffer);
  92 }
  93 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
  94
  95 static void devm_iio_triggered_buffer_clean(struct device *dev, void *res)
  96 {
  97         iio_triggered_buffer_cleanup(*(struct iio_dev **)res);
  98 }
  99
 100 int devm_iio_triggered_buffer_setup_ext(struct device *dev,
 101                                         struct iio_dev *indio_dev,
 102                                         irqreturn_t (*h)(int irq, void *p),
 103                                         irqreturn_t (*thread)(int irq, void *p),
 104                                         const struct iio_buffer_setup_ops *ops,
 105                                         const struct attribute **buffer_attrs)
 106 {
 107         struct iio_dev **ptr;
 108         int ret;
 109
 110         ptr = devres_alloc(devm_iio_triggered_buffer_clean, sizeof(*ptr),
 111                            GFP_KERNEL);
 112         if (!ptr)
 113                 return -ENOMEM;
 114
 115         *ptr = indio_dev;
 116
 117         ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, ops,
 118                                              buffer_attrs);
 119         if (!ret)
 120                 devres_add(dev, ptr);
 121         else
 122                 devres_free(ptr);
 123
 124         return ret;
 125 }
 126 EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext);
 127
 128 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 129 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
 130 MODULE_LICENSE("GPL");