| Mauro Carvalho Chehab | 059b1c5 | 2020-08-26 09:03:09 +0200 | [diff] [blame] | 1 | .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later |
| Mauro Carvalho Chehab | f9b2e8a | 2020-09-24 16:56:00 +0200 | [diff] [blame] | 2 | .. c:namespace:: DTV.fe |
| Mauro Carvalho Chehab | 54f38fc | 2020-03-04 10:21:39 +0100 | [diff] [blame] | 3 | |
| 4 | .. _FE_READ_SIGNAL_STRENGTH: |
| 5 | |
| 6 | *********************** |
| 7 | FE_READ_SIGNAL_STRENGTH |
| 8 | *********************** |
| 9 | |
| 10 | Name |
| 11 | ==== |
| 12 | |
| 13 | FE_READ_SIGNAL_STRENGTH |
| 14 | |
| 15 | .. attention:: This ioctl is deprecated. |
| 16 | |
| 17 | Synopsis |
| 18 | ======== |
| 19 | |
| Mauro Carvalho Chehab | f9b2e8a | 2020-09-24 16:56:00 +0200 | [diff] [blame] | 20 | .. c:macro:: FE_READ_SIGNAL_STRENGTH |
| Mauro Carvalho Chehab | 54f38fc | 2020-03-04 10:21:39 +0100 | [diff] [blame] | 21 | |
| Mauro Carvalho Chehab | f9b2e8a | 2020-09-24 16:56:00 +0200 | [diff] [blame] | 22 | ``int ioctl(int fd, FE_READ_SIGNAL_STRENGTH, uint16_t *strength)`` |
| Mauro Carvalho Chehab | 54f38fc | 2020-03-04 10:21:39 +0100 | [diff] [blame] | 23 | |
| 24 | Arguments |
| 25 | ========= |
| 26 | |
| 27 | ``fd`` |
| Mauro Carvalho Chehab | f9b2e8a | 2020-09-24 16:56:00 +0200 | [diff] [blame] | 28 | File descriptor returned by :c:func:`open()`. |
| Mauro Carvalho Chehab | 54f38fc | 2020-03-04 10:21:39 +0100 | [diff] [blame] | 29 | |
| 30 | ``strength`` |
| 31 | The signal strength value is stored into \*strength. |
| 32 | |
| Mauro Carvalho Chehab | 54f38fc | 2020-03-04 10:21:39 +0100 | [diff] [blame] | 33 | Description |
| 34 | =========== |
| 35 | |
| 36 | This ioctl call returns the signal strength value for the signal |
| 37 | currently received by the front-end. For this command, read-only access |
| 38 | to the device is sufficient. |
| 39 | |
| Mauro Carvalho Chehab | 54f38fc | 2020-03-04 10:21:39 +0100 | [diff] [blame] | 40 | Return Value |
| 41 | ============ |
| 42 | |
| 43 | On success 0 is returned. |
| 44 | |
| 45 | On error -1 is returned, and the ``errno`` variable is set |
| 46 | appropriately. |
| 47 | |
| 48 | Generic error codes are described at the |
| 49 | :ref:`Generic Error Codes <gen-errors>` chapter. |