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