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"); 152