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Diffstat (limited to 'include/media/cec-edid.h')
| -rw-r--r-- | include/media/cec-edid.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/include/media/cec-edid.h b/include/media/cec-edid.h new file mode 100644 index 000000000000..bdf731ecba1a --- /dev/null +++ b/include/media/cec-edid.h @@ -0,0 +1,104 @@ +/* + * cec-edid - HDMI Consumer Electronics Control & EDID helpers + * + * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved. + * + * This program is free software; you may redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#ifndef _MEDIA_CEC_EDID_H +#define _MEDIA_CEC_EDID_H + +#include <linux/types.h> + +#define CEC_PHYS_ADDR_INVALID 0xffff +#define cec_phys_addr_exp(pa) \ + ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf + +/** + * cec_get_edid_phys_addr() - find and return the physical address + * + * @edid: pointer to the EDID data + * @size: size in bytes of the EDID data + * @offset: If not %NULL then the location of the physical address + * bytes in the EDID will be returned here. This is set to 0 + * if there is no physical address found. + * + * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. + */ +u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, + unsigned int *offset); + +/** + * cec_set_edid_phys_addr() - find and set the physical address + * + * @edid: pointer to the EDID data + * @size: size in bytes of the EDID data + * @phys_addr: the new physical address + * + * This function finds the location of the physical address in the EDID + * and fills in the given physical address and updates the checksum + * at the end of the EDID block. It does nothing if the EDID doesn't + * contain a physical address. + */ +void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr); + +/** + * cec_phys_addr_for_input() - calculate the PA for an input + * + * @phys_addr: the physical address of the parent + * @input: the number of the input port, must be between 1 and 15 + * + * This function calculates a new physical address based on the input + * port number. For example: + * + * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0 + * + * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0 + * + * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5 + * + * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth. + * + * Return: the new physical address or CEC_PHYS_ADDR_INVALID. + */ +u16 cec_phys_addr_for_input(u16 phys_addr, u8 input); + +/** + * cec_phys_addr_validate() - validate a physical address from an EDID + * + * @phys_addr: the physical address to validate + * @parent: if not %NULL, then this is filled with the parents PA. + * @port: if not %NULL, then this is filled with the input port. + * + * This validates a physical address as read from an EDID. If the + * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end), + * then it will return -EINVAL. + * + * The parent PA is passed into %parent and the input port is passed into + * %port. For example: + * + * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0. + * + * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1. + * + * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2. + * + * PA = f.f.f.f: has parent f.f.f.f and input port 0. + * + * Return: 0 if the PA is valid, -EINVAL if not. + */ +int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port); + +#endif /* _MEDIA_CEC_EDID_H */ |