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 static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
  17         .postenable = &iio_triggered_buffer_postenable,
  18         .predisable = &iio_triggered_buffer_predisable,
  19 };
  20
  21 /**
  22  * iio_triggered_buffer_setup() - Setup triggered buffer and pollfunc
  23  * @indio_dev:          IIO device structure
  24  * @h:                  Function which will be used as pollfunc top half
  25  * @thread:             Function which will be used as pollfunc bottom half
  26  * @setup_ops:          Buffer setup functions to use for this device.
  27  *                      If NULL the default setup functions for triggered
  28  *                      buffers will be used.
  29  *
  30  * This function combines some common tasks which will normally be performed
  31  * when setting up a triggered buffer. It will allocate the buffer and the
  32  * pollfunc.
  33  *
  34  * Before calling this function the indio_dev structure should already be
  35  * completely initialized, but not yet registered. In practice this means that
  36  * this function should be called right before iio_device_register().
  37  *
  38  * To free the resources allocated by this function call
  39  * iio_triggered_buffer_cleanup().
  40  */
  41 int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
  42         irqreturn_t (*h)(int irq, void *p),
  43         irqreturn_t (*thread)(int irq, void *p),
  44         const struct iio_buffer_setup_ops *setup_ops)
  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         iio_device_attach_buffer(indio_dev, buffer);
  56
  57         indio_dev->pollfunc = iio_alloc_pollfunc(h,
  58                                                  thread,
  59                                                  IRQF_ONESHOT,
  60                                                  indio_dev,
  61                                                  "%s_consumer%d",
  62                                                  indio_dev->name,
  63                                                  indio_dev->id);
  64         if (indio_dev->pollfunc == NULL) {
  65                 ret = -ENOMEM;
  66                 goto error_kfifo_free;
  67         }
  68
  69         /* Ring buffer functions - here trigger setup related */
  70         if (setup_ops)
  71                 indio_dev->setup_ops = setup_ops;
  72         else
  73                 indio_dev->setup_ops = &iio_triggered_buffer_setup_ops;
  74
  75         /* Flag that polled ring buffering is possible */
  76         indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
  77
  78         return 0;
  79
  80 error_kfifo_free:
  81         iio_kfifo_free(indio_dev->buffer);
  82 error_ret:
  83         return ret;
  84 }
  85 EXPORT_SYMBOL(iio_triggered_buffer_setup);
  86
  87 /**
  88  * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup()
  89  * @indio_dev: IIO device structure
  90  */
  91 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
  92 {
  93         iio_dealloc_pollfunc(indio_dev->pollfunc);
  94         iio_kfifo_free(indio_dev->buffer);
  95 }
  96 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
  97
  98 static void devm_iio_triggered_buffer_clean(struct device *dev, void *res)
  99 {
 100         iio_triggered_buffer_cleanup(*(struct iio_dev **)res);
 101 }
 102
 103 int devm_iio_triggered_buffer_setup(struct device *dev,
 104                                     struct iio_dev *indio_dev,
 105                                     irqreturn_t (*h)(int irq, void *p),
 106                                     irqreturn_t (*thread)(int irq, void *p),
 107                                     const struct iio_buffer_setup_ops *ops)
 108 {
 109         struct iio_dev **ptr;
 110         int ret;
 111
 112         ptr = devres_alloc(devm_iio_triggered_buffer_clean, sizeof(*ptr),
 113                            GFP_KERNEL);
 114         if (!ptr)
 115                 return -ENOMEM;
 116
 117         *ptr = indio_dev;
 118
 119         ret = iio_triggered_buffer_setup(indio_dev, h, thread, ops);
 120         if (!ret)
 121                 devres_add(dev, ptr);
 122         else
 123                 devres_free(ptr);
 124
 125         return ret;
 126 }
 127 EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup);
 128
 129 void devm_iio_triggered_buffer_cleanup(struct device *dev,
 130                                        struct iio_dev *indio_dev)
 131 {
 132         int rc;
 133
 134         rc = devres_release(dev, devm_iio_triggered_buffer_clean,
 135                             devm_iio_device_match, indio_dev);
 136         WARN_ON(rc);
 137 }
 138 EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_cleanup);
 139
 140 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 141 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
 142 MODULE_LICENSE("GPL");