Commit | Line | Data |
---|---|---|
670b19ae LPC |
1 | /* |
2 | * Copyright 2013-2015 Analog Devices Inc. | |
3 | * Author: Lars-Peter Clausen <lars@metafoo.de> | |
4 | * | |
5 | * Licensed under the GPL-2. | |
6 | */ | |
7 | ||
8 | #ifndef __INDUSTRIALIO_DMA_BUFFER_H__ | |
9 | #define __INDUSTRIALIO_DMA_BUFFER_H__ | |
10 | ||
11 | #include <linux/list.h> | |
12 | #include <linux/kref.h> | |
13 | #include <linux/spinlock.h> | |
14 | #include <linux/mutex.h> | |
15 | #include <linux/iio/buffer.h> | |
16 | ||
17 | struct iio_dma_buffer_queue; | |
18 | struct iio_dma_buffer_ops; | |
19 | struct device; | |
20 | ||
21 | struct iio_buffer_block { | |
22 | u32 size; | |
23 | u32 bytes_used; | |
24 | }; | |
25 | ||
26 | /** | |
27 | * enum iio_block_state - State of a struct iio_dma_buffer_block | |
28 | * @IIO_BLOCK_STATE_DEQUEUED: Block is not queued | |
29 | * @IIO_BLOCK_STATE_QUEUED: Block is on the incoming queue | |
30 | * @IIO_BLOCK_STATE_ACTIVE: Block is currently being processed by the DMA | |
31 | * @IIO_BLOCK_STATE_DONE: Block is on the outgoing queue | |
32 | * @IIO_BLOCK_STATE_DEAD: Block has been marked as to be freed | |
33 | */ | |
34 | enum iio_block_state { | |
35 | IIO_BLOCK_STATE_DEQUEUED, | |
36 | IIO_BLOCK_STATE_QUEUED, | |
37 | IIO_BLOCK_STATE_ACTIVE, | |
38 | IIO_BLOCK_STATE_DONE, | |
39 | IIO_BLOCK_STATE_DEAD, | |
40 | }; | |
41 | ||
42 | /** | |
43 | * struct iio_dma_buffer_block - IIO buffer block | |
44 | * @head: List head | |
45 | * @size: Total size of the block in bytes | |
46 | * @bytes_used: Number of bytes that contain valid data | |
47 | * @vaddr: Virutal address of the blocks memory | |
48 | * @phys_addr: Physical address of the blocks memory | |
49 | * @queue: Parent DMA buffer queue | |
50 | * @kref: kref used to manage the lifetime of block | |
51 | * @state: Current state of the block | |
52 | */ | |
53 | struct iio_dma_buffer_block { | |
54 | /* May only be accessed by the owner of the block */ | |
55 | struct list_head head; | |
56 | size_t bytes_used; | |
57 | ||
58 | /* | |
59 | * Set during allocation, constant thereafter. May be accessed read-only | |
60 | * by anybody holding a reference to the block. | |
61 | */ | |
62 | void *vaddr; | |
63 | dma_addr_t phys_addr; | |
64 | size_t size; | |
65 | struct iio_dma_buffer_queue *queue; | |
66 | ||
67 | /* Must not be accessed outside the core. */ | |
68 | struct kref kref; | |
69 | /* | |
70 | * Must not be accessed outside the core. Access needs to hold | |
71 | * queue->list_lock if the block is not owned by the core. | |
72 | */ | |
73 | enum iio_block_state state; | |
74 | }; | |
75 | ||
76 | /** | |
77 | * struct iio_dma_buffer_queue_fileio - FileIO state for the DMA buffer | |
78 | * @blocks: Buffer blocks used for fileio | |
79 | * @active_block: Block being used in read() | |
80 | * @pos: Read offset in the active block | |
81 | * @block_size: Size of each block | |
82 | */ | |
83 | struct iio_dma_buffer_queue_fileio { | |
84 | struct iio_dma_buffer_block *blocks[2]; | |
85 | struct iio_dma_buffer_block *active_block; | |
86 | size_t pos; | |
87 | size_t block_size; | |
88 | }; | |
89 | ||
90 | /** | |
91 | * struct iio_dma_buffer_queue - DMA buffer base structure | |
92 | * @buffer: IIO buffer base structure | |
93 | * @dev: Parent device | |
94 | * @ops: DMA buffer callbacks | |
95 | * @lock: Protects the incoming list, active and the fields in the fileio | |
96 | * substruct | |
97 | * @list_lock: Protects lists that contain blocks which can be modified in | |
98 | * atomic context as well as blocks on those lists. This is the outgoing queue | |
99 | * list and typically also a list of active blocks in the part that handles | |
100 | * the DMA controller | |
101 | * @incoming: List of buffers on the incoming queue | |
102 | * @outgoing: List of buffers on the outgoing queue | |
103 | * @active: Whether the buffer is currently active | |
104 | * @fileio: FileIO state | |
105 | */ | |
106 | struct iio_dma_buffer_queue { | |
107 | struct iio_buffer buffer; | |
108 | struct device *dev; | |
109 | const struct iio_dma_buffer_ops *ops; | |
110 | ||
111 | struct mutex lock; | |
112 | spinlock_t list_lock; | |
113 | struct list_head incoming; | |
114 | struct list_head outgoing; | |
115 | ||
116 | bool active; | |
117 | ||
118 | struct iio_dma_buffer_queue_fileio fileio; | |
119 | }; | |
120 | ||
121 | /** | |
122 | * struct iio_dma_buffer_ops - DMA buffer callback operations | |
123 | * @submit: Called when a block is submitted to the DMA controller | |
124 | * @abort: Should abort all pending transfers | |
125 | */ | |
126 | struct iio_dma_buffer_ops { | |
127 | int (*submit)(struct iio_dma_buffer_queue *queue, | |
128 | struct iio_dma_buffer_block *block); | |
129 | void (*abort)(struct iio_dma_buffer_queue *queue); | |
130 | }; | |
131 | ||
132 | void iio_dma_buffer_block_done(struct iio_dma_buffer_block *block); | |
133 | void iio_dma_buffer_block_list_abort(struct iio_dma_buffer_queue *queue, | |
134 | struct list_head *list); | |
135 | ||
136 | int iio_dma_buffer_enable(struct iio_buffer *buffer, | |
137 | struct iio_dev *indio_dev); | |
138 | int iio_dma_buffer_disable(struct iio_buffer *buffer, | |
139 | struct iio_dev *indio_dev); | |
140 | int iio_dma_buffer_read(struct iio_buffer *buffer, size_t n, | |
141 | char __user *user_buffer); | |
142 | size_t iio_dma_buffer_data_available(struct iio_buffer *buffer); | |
143 | int iio_dma_buffer_set_bytes_per_datum(struct iio_buffer *buffer, size_t bpd); | |
144 | int iio_dma_buffer_set_length(struct iio_buffer *buffer, int length); | |
145 | int iio_dma_buffer_request_update(struct iio_buffer *buffer); | |
146 | ||
147 | int iio_dma_buffer_init(struct iio_dma_buffer_queue *queue, | |
148 | struct device *dma_dev, const struct iio_dma_buffer_ops *ops); | |
149 | void iio_dma_buffer_exit(struct iio_dma_buffer_queue *queue); | |
150 | void iio_dma_buffer_release(struct iio_dma_buffer_queue *queue); | |
151 | ||
152 | #endif |