| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * cec-edid - HDMI Consumer Electronics Control EDID & CEC helper functions |
| 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 | #include <linux/module.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/types.h> |
| 23 | #include <media/cec.h> |
| 24 | |
| 25 | u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, |
| 26 | unsigned int *offset) |
| 27 | { |
| 28 | unsigned int loc = cec_get_edid_spa_location(edid, size); |
| 29 | |
| 30 | if (offset) |
| 31 | *offset = loc; |
| 32 | if (loc == 0) |
| 33 | return CEC_PHYS_ADDR_INVALID; |
| 34 | return (edid[loc] << 8) | edid[loc + 1]; |
| 35 | } |
| 36 | EXPORT_SYMBOL_GPL(cec_get_edid_phys_addr); |
| 37 | |
| 38 | void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr) |
| 39 | { |
| 40 | unsigned int loc = cec_get_edid_spa_location(edid, size); |
| 41 | u8 sum = 0; |
| 42 | unsigned int i; |
| 43 | |
| 44 | if (loc == 0) |
| 45 | return; |
| 46 | edid[loc] = phys_addr >> 8; |
| 47 | edid[loc + 1] = phys_addr & 0xff; |
| 48 | loc &= ~0x7f; |
| 49 | |
| 50 | /* update the checksum */ |
| 51 | for (i = loc; i < loc + 127; i++) |
| 52 | sum += edid[i]; |
| 53 | edid[i] = 256 - sum; |
| 54 | } |
| 55 | EXPORT_SYMBOL_GPL(cec_set_edid_phys_addr); |
| 56 | |
| 57 | u16 cec_phys_addr_for_input(u16 phys_addr, u8 input) |
| 58 | { |
| 59 | /* Check if input is sane */ |
| 60 | if (WARN_ON(input == 0 || input > 0xf)) |
| 61 | return CEC_PHYS_ADDR_INVALID; |
| 62 | |
| 63 | if (phys_addr == 0) |
| 64 | return input << 12; |
| 65 | |
| 66 | if ((phys_addr & 0x0fff) == 0) |
| 67 | return phys_addr | (input << 8); |
| 68 | |
| 69 | if ((phys_addr & 0x00ff) == 0) |
| 70 | return phys_addr | (input << 4); |
| 71 | |
| 72 | if ((phys_addr & 0x000f) == 0) |
| 73 | return phys_addr | input; |
| 74 | |
| 75 | /* |
| 76 | * All nibbles are used so no valid physical addresses can be assigned |
| 77 | * to the input. |
| 78 | */ |
| 79 | return CEC_PHYS_ADDR_INVALID; |
| 80 | } |
| 81 | EXPORT_SYMBOL_GPL(cec_phys_addr_for_input); |
| 82 | |
| 83 | int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port) |
| 84 | { |
| 85 | int i; |
| 86 | |
| 87 | if (parent) |
| 88 | *parent = phys_addr; |
| 89 | if (port) |
| 90 | *port = 0; |
| 91 | if (phys_addr == CEC_PHYS_ADDR_INVALID) |
| 92 | return 0; |
| 93 | for (i = 0; i < 16; i += 4) |
| 94 | if (phys_addr & (0xf << i)) |
| 95 | break; |
| 96 | if (i == 16) |
| 97 | return 0; |
| 98 | if (parent) |
| 99 | *parent = phys_addr & (0xfff0 << i); |
| 100 | if (port) |
| 101 | *port = (phys_addr >> i) & 0xf; |
| 102 | for (i += 4; i < 16; i += 4) |
| 103 | if ((phys_addr & (0xf << i)) == 0) |
| 104 | return -EINVAL; |
| 105 | return 0; |
| 106 | } |
| 107 | EXPORT_SYMBOL_GPL(cec_phys_addr_validate); |