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         if (!cb) {
  58                 dev_err(dev, "Invalid arguments: A callback must be provided!\n");
  59                 return ERR_PTR(-EINVAL);
  60         }
  61
  62         cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
  63         if (cb_buff == NULL)
  64                 return ERR_PTR(-ENOMEM);
  65
  66         iio_buffer_init(&cb_buff->buffer);
  67
  68         cb_buff->private = private;
  69         cb_buff->cb = cb;
  70         cb_buff->buffer.access = &iio_cb_access;
  71         INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
  72
  73         cb_buff->channels = iio_channel_get_all(dev);
  74         if (IS_ERR(cb_buff->channels)) {
  75                 ret = PTR_ERR(cb_buff->channels);
  76                 goto error_free_cb_buff;
  77         }
  78
  79         cb_buff->indio_dev = cb_buff->channels[0].indio_dev;
  80         cb_buff->buffer.scan_mask = bitmap_zalloc(cb_buff->indio_dev->masklength,
  81                                                   GFP_KERNEL);
  82         if (cb_buff->buffer.scan_mask == NULL) {
  83                 ret = -ENOMEM;
  84                 goto error_release_channels;
  85         }
  86         chan = &cb_buff->channels[0];
  87         while (chan->indio_dev) {
  88                 if (chan->indio_dev != cb_buff->indio_dev) {
  89                         ret = -EINVAL;
  90                         goto error_free_scan_mask;
  91                 }
  92                 set_bit(chan->channel->scan_index,
  93                         cb_buff->buffer.scan_mask);
  94                 chan++;
  95         }
  96
  97         return cb_buff;
  98
  99 error_free_scan_mask:
 100         bitmap_free(cb_buff->buffer.scan_mask);
 101 error_release_channels:
 102         iio_channel_release_all(cb_buff->channels);
 103 error_free_cb_buff:
 104         kfree(cb_buff);
 105         return ERR_PTR(ret);
 106 }
 107 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
 108
 109 int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buff,
 110                                         size_t watermark)
 111 {
 112         if (!watermark)
 113                 return -EINVAL;
 114         cb_buff->buffer.watermark = watermark;
 115
 116         return 0;
 117 }
 118 EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
 119
 120 int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
 121 {
 122         return iio_update_buffers(cb_buff->indio_dev, &cb_buff->buffer,
 123                                   NULL);
 124 }
 125 EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
 126
 127 void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
 128 {
 129         iio_update_buffers(cb_buff->indio_dev, NULL, &cb_buff->buffer);
 130 }
 131 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 132
 133 void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
 134 {
 135         iio_channel_release_all(cb_buff->channels);
 136         iio_buffer_put(&cb_buff->buffer);
 137 }
 138 EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
 139
 140 struct iio_channel
 141 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
 142 {
 143         return cb_buffer->channels;
 144 }
 145 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
 146
 147 struct iio_dev
 148 *iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
 149 {
 150         return cb_buffer->indio_dev;
 151 }
 152 EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
 153
 154 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 155 MODULE_DESCRIPTION("Industrial I/O callback buffer");
 156 MODULE_LICENSE("GPL");