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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* The industrial I/O callback buffer
   3  */
   4
   5 #include <linux/kernel.h>
   6 #include <linux/module.h>
   7 #include <linux/slab.h>
   8 #include <linux/err.h>
   9 #include <linux/export.h>
  10 #include <linux/iio/iio.h>
  11 #include <linux/iio/buffer_impl.h>
  12 #include <linux/iio/consumer.h>
  13
  14 struct iio_cb_buffer {
  15         struct iio_buffer buffer;
  16         int (*cb)(const void *data, void *private);
  17         void *private;
  18         struct iio_channel *channels;
  19         struct iio_dev *indio_dev;
  20 };
  21
  22 static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
  23 {
  24         return container_of(buffer, struct iio_cb_buffer, buffer);
  25 }
  26
  27 static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
  28 {
  29         struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
  30         return cb_buff->cb(data, cb_buff->private);
  31 }
  32
  33 static void iio_buffer_cb_release(struct iio_buffer *buffer)
  34 {
  35         struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
  36
  37         bitmap_free(cb_buff->buffer.scan_mask);
  38         kfree(cb_buff);
  39 }
  40
  41 static const struct iio_buffer_access_funcs iio_cb_access = {
  42         .store_to = &iio_buffer_cb_store_to,
  43         .release = &iio_buffer_cb_release,
  44
  45         .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
  46 };
  47
  48 struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
  49                                              int (*cb)(const void *data,
  50                                                        void *private),
  51                                              void *private)
  52 {
  53         int ret;
  54         struct iio_cb_buffer *cb_buff;
  55         struct iio_channel *chan;
  56
  57         cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
  58         if (cb_buff == NULL)
  59                 return ERR_PTR(-ENOMEM);
  60
  61         iio_buffer_init(&cb_buff->buffer);
  62
  63         cb_buff->private = private;
  64         cb_buff->cb = cb;
  65         cb_buff->buffer.access = &iio_cb_access;
  66         INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
  67
  68         cb_buff->channels = iio_channel_get_all(dev);
  69         if (IS_ERR(cb_buff->channels)) {
  70                 ret = PTR_ERR(cb_buff->channels);
  71                 goto error_free_cb_buff;
  72         }
  73
  74         cb_buff->indio_dev = cb_buff->channels[0].indio_dev;
  75         cb_buff->buffer.scan_mask = bitmap_zalloc(cb_buff->indio_dev->masklength,
  76                                                   GFP_KERNEL);
  77         if (cb_buff->buffer.scan_mask == NULL) {
  78                 ret = -ENOMEM;
  79                 goto error_release_channels;
  80         }
  81         chan = &cb_buff->channels[0];
  82         while (chan->indio_dev) {
  83                 if (chan->indio_dev != cb_buff->indio_dev) {
  84                         ret = -EINVAL;
  85                         goto error_free_scan_mask;
  86                 }
  87                 set_bit(chan->channel->scan_index,
  88                         cb_buff->buffer.scan_mask);
  89                 chan++;
  90         }
  91
  92         return cb_buff;
  93
  94 error_free_scan_mask:
  95         bitmap_free(cb_buff->buffer.scan_mask);
  96 error_release_channels:
  97         iio_channel_release_all(cb_buff->channels);
  98 error_free_cb_buff:
  99         kfree(cb_buff);
 100         return ERR_PTR(ret);
 101 }
 102 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
 103
 104 int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buff,
 105                                         size_t watermark)
 106 {
 107         if (!watermark)
 108                 return -EINVAL;
 109         cb_buff->buffer.watermark = watermark;
 110
 111         return 0;
 112 }
 113 EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
 114
 115 int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
 116 {
 117         return iio_update_buffers(cb_buff->indio_dev, &cb_buff->buffer,
 118                                   NULL);
 119 }
 120 EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
 121
 122 void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
 123 {
 124         iio_update_buffers(cb_buff->indio_dev, NULL, &cb_buff->buffer);
 125 }
 126 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 127
 128 void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
 129 {
 130         iio_channel_release_all(cb_buff->channels);
 131         iio_buffer_put(&cb_buff->buffer);
 132 }
 133 EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
 134
 135 struct iio_channel
 136 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
 137 {
 138         return cb_buffer->channels;
 139 }
 140 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
 141
 142 struct iio_dev
 143 *iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
 144 {
 145         return cb_buffer->indio_dev;
 146 }
 147 EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
 148
 149 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 150 MODULE_DESCRIPTION("Industrial I/O callback buffer");
 151 MODULE_LICENSE("GPL");