include/media/cec-edid.h

   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  */
  40 u16 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  */
  55 void 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  */
  76 u16 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  */
 102 int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port);
 103
 104 #endif /* _MEDIA_CEC_EDID_H */