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 <[email protected]>
   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         indio_dev->pollfunc = iio_alloc_pollfunc(h,
  54                                                  thread,
  55                                                  IRQF_ONESHOT,
  56                                                  indio_dev,
  57                                                  "%s_consumer%d",
  58                                                  indio_dev->name,
  59                                                  indio_dev->id);
  60         if (indio_dev->pollfunc == NULL) {
  61                 ret = -ENOMEM;
  62                 goto error_kfifo_free;
  63         }
  64
  65         /* Ring buffer functions - here trigger setup related */
  66         indio_dev->setup_ops = setup_ops;
  67
  68         /* Flag that polled ring buffering is possible */
  69         indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
  70
  71         buffer->attrs = buffer_attrs;
  72
  73         ret = iio_device_attach_buffer(indio_dev, buffer);
  74         if (ret < 0)
  75                 goto error_dealloc_pollfunc;
  76
  77         return 0;
  78
  79 error_dealloc_pollfunc:
  80         iio_dealloc_pollfunc(indio_dev->pollfunc);
  81 error_kfifo_free:
  82         iio_kfifo_free(buffer);
  83 error_ret:
  84         return ret;
  85 }
  86 EXPORT_SYMBOL(iio_triggered_buffer_setup_ext);
  87
  88 /**
  89  * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext()
  90  * @indio_dev: IIO device structure
  91  */
  92 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
  93 {
  94         iio_dealloc_pollfunc(indio_dev->pollfunc);
  95         iio_kfifo_free(indio_dev->buffer);
  96 }
  97 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
  98
  99 static void devm_iio_triggered_buffer_clean(struct device *dev, void *res)
 100 {
 101         iio_triggered_buffer_cleanup(*(struct iio_dev **)res);
 102 }
 103
 104 int devm_iio_triggered_buffer_setup_ext(struct device *dev,
 105                                         struct iio_dev *indio_dev,
 106                                         irqreturn_t (*h)(int irq, void *p),
 107                                         irqreturn_t (*thread)(int irq, void *p),
 108                                         const struct iio_buffer_setup_ops *ops,
 109                                         const struct attribute **buffer_attrs)
 110 {
 111         struct iio_dev **ptr;
 112         int ret;
 113
 114         ptr = devres_alloc(devm_iio_triggered_buffer_clean, sizeof(*ptr),
 115                            GFP_KERNEL);
 116         if (!ptr)
 117                 return -ENOMEM;
 118
 119         *ptr = indio_dev;
 120
 121         ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, ops,
 122                                              buffer_attrs);
 123         if (!ret)
 124                 devres_add(dev, ptr);
 125         else
 126                 devres_free(ptr);
 127
 128         return ret;
 129 }
 130 EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext);
 131
 132 MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>");
 133 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
 134 MODULE_LICENSE("GPL");