diff options
| -rw-r--r-- | drivers/media/cec/cec-edid.c | 60 | ||||
| -rw-r--r-- | include/media/cec.h | 70 |
2 files changed, 70 insertions, 60 deletions
diff --git a/drivers/media/cec/cec-edid.c b/drivers/media/cec/cec-edid.c index ec72ac1c0b91..f587e8eaefd8 100644 --- a/drivers/media/cec/cec-edid.c +++ b/drivers/media/cec/cec-edid.c @@ -10,66 +10,6 @@ #include <linux/types.h> #include <media/cec.h> -/* - * This EDID is expected to be a CEA-861 compliant, which means that there are - * at least two blocks and one or more of the extensions blocks are CEA-861 - * blocks. - * - * The returned location is guaranteed to be < size - 1. - */ -static unsigned int cec_get_edid_spa_location(const u8 *edid, unsigned int size) -{ - unsigned int blocks = size / 128; - unsigned int block; - u8 d; - - /* Sanity check: at least 2 blocks and a multiple of the block size */ - if (blocks < 2 || size % 128) - return 0; - - /* - * If there are fewer extension blocks than the size, then update - * 'blocks'. It is allowed to have more extension blocks than the size, - * since some hardware can only read e.g. 256 bytes of the EDID, even - * though more blocks are present. The first CEA-861 extension block - * should normally be in block 1 anyway. - */ - if (edid[0x7e] + 1 < blocks) - blocks = edid[0x7e] + 1; - - for (block = 1; block < blocks; block++) { - unsigned int offset = block * 128; - - /* Skip any non-CEA-861 extension blocks */ - if (edid[offset] != 0x02 || edid[offset + 1] != 0x03) - continue; - - /* search Vendor Specific Data Block (tag 3) */ - d = edid[offset + 2] & 0x7f; - /* Check if there are Data Blocks */ - if (d <= 4) - continue; - if (d > 4) { - unsigned int i = offset + 4; - unsigned int end = offset + d; - - /* Note: 'end' is always < 'size' */ - do { - u8 tag = edid[i] >> 5; - u8 len = edid[i] & 0x1f; - - if (tag == 3 && len >= 5 && i + len <= end && - edid[i + 1] == 0x03 && - edid[i + 2] == 0x0c && - edid[i + 3] == 0x00) - return i + 4; - i += len + 1; - } while (i < end); - } - } - return 0; -} - u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, unsigned int *offset) { diff --git a/include/media/cec.h b/include/media/cec.h index ff9847f7f99d..603f2fa08f62 100644 --- a/include/media/cec.h +++ b/include/media/cec.h @@ -461,4 +461,74 @@ static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); } +/** + * cec_get_edid_spa_location() - find location of the Source Physical Address + * + * @edid: the EDID + * @size: the size of the EDID + * + * This EDID is expected to be a CEA-861 compliant, which means that there are + * at least two blocks and one or more of the extensions blocks are CEA-861 + * blocks. + * + * The returned location is guaranteed to be <= size-2. + * + * This is an inline function since it is used by both CEC and V4L2. + * Ideally this would go in a module shared by both, but it is overkill to do + * that for just a single function. + */ +static inline unsigned int cec_get_edid_spa_location(const u8 *edid, + unsigned int size) +{ + unsigned int blocks = size / 128; + unsigned int block; + u8 d; + + /* Sanity check: at least 2 blocks and a multiple of the block size */ + if (blocks < 2 || size % 128) + return 0; + + /* + * If there are fewer extension blocks than the size, then update + * 'blocks'. It is allowed to have more extension blocks than the size, + * since some hardware can only read e.g. 256 bytes of the EDID, even + * though more blocks are present. The first CEA-861 extension block + * should normally be in block 1 anyway. + */ + if (edid[0x7e] + 1 < blocks) + blocks = edid[0x7e] + 1; + + for (block = 1; block < blocks; block++) { + unsigned int offset = block * 128; + + /* Skip any non-CEA-861 extension blocks */ + if (edid[offset] != 0x02 || edid[offset + 1] != 0x03) + continue; + + /* search Vendor Specific Data Block (tag 3) */ + d = edid[offset + 2] & 0x7f; + /* Check if there are Data Blocks */ + if (d <= 4) + continue; + if (d > 4) { + unsigned int i = offset + 4; + unsigned int end = offset + d; + + /* Note: 'end' is always < 'size' */ + do { + u8 tag = edid[i] >> 5; + u8 len = edid[i] & 0x1f; + + if (tag == 3 && len >= 5 && i + len <= end && + edid[i + 1] == 0x03 && + edid[i + 2] == 0x0c && + edid[i + 3] == 0x00) + return i + 4; + i += len + 1; + } while (i < end); + } + } + return 0; +} + #endif /* _MEDIA_CEC_H */ |