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(iio_get_masklength(cb_buff->indio_dev), 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"); 157