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1/*
2 * cec-edid - HDMI Consumer Electronics Control & EDID helpers
3 *
4 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
5 *
6 * This program is free software; you may redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
11 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
12 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
13 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
14 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
15 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
16 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
17 * SOFTWARE.
18 */
19
20#ifndef _MEDIA_CEC_EDID_H
21#define _MEDIA_CEC_EDID_H
22
23#include <linux/types.h>
24
25#define CEC_PHYS_ADDR_INVALID 0xffff
26#define cec_phys_addr_exp(pa) \
27 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
28
29/**
30 * cec_get_edid_phys_addr() - find and return the physical address
31 *
32 * @edid: pointer to the EDID data
33 * @size: size in bytes of the EDID data
34 * @offset: If not %NULL then the location of the physical address
35 * bytes in the EDID will be returned here. This is set to 0
36 * if there is no physical address found.
37 *
38 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
39 */
40u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
41 unsigned int *offset);
42
43/**
44 * cec_set_edid_phys_addr() - find and set the physical address
45 *
46 * @edid: pointer to the EDID data
47 * @size: size in bytes of the EDID data
48 * @phys_addr: the new physical address
49 *
50 * This function finds the location of the physical address in the EDID
51 * and fills in the given physical address and updates the checksum
52 * at the end of the EDID block. It does nothing if the EDID doesn't
53 * contain a physical address.
54 */
55void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr);
56
57/**
58 * cec_phys_addr_for_input() - calculate the PA for an input
59 *
60 * @phys_addr: the physical address of the parent
61 * @input: the number of the input port, must be between 1 and 15
62 *
63 * This function calculates a new physical address based on the input
64 * port number. For example:
65 *
66 * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0
67 *
68 * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0
69 *
70 * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5
71 *
72 * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth.
73 *
74 * Return: the new physical address or CEC_PHYS_ADDR_INVALID.
75 */
76u16 cec_phys_addr_for_input(u16 phys_addr, u8 input);
77
78/**
79 * cec_phys_addr_validate() - validate a physical address from an EDID
80 *
81 * @phys_addr: the physical address to validate
82 * @parent: if not %NULL, then this is filled with the parents PA.
83 * @port: if not %NULL, then this is filled with the input port.
84 *
85 * This validates a physical address as read from an EDID. If the
86 * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end),
87 * then it will return -EINVAL.
88 *
89 * The parent PA is passed into %parent and the input port is passed into
90 * %port. For example:
91 *
92 * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0.
93 *
94 * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1.
95 *
96 * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2.
97 *
98 * PA = f.f.f.f: has parent f.f.f.f and input port 0.
99 *
100 * Return: 0 if the PA is valid, -EINVAL if not.
101 */
102int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port);
103
104#endif /* _MEDIA_CEC_EDID_H */