| Scott Kanowitz | f4ff415 | 2014-06-12 16:22:15 -0400 | [diff] [blame] | 1 | Kernel driver powr1220 |
| 2 | ================== |
| 3 | |
| 4 | Supported chips: |
| 5 | * Lattice POWR1220AT8 |
| 6 | Prefix: 'powr1220' |
| 7 | Addresses scanned: none |
| 8 | Datasheet: Publicly available at the Lattice website |
| 9 | http://www.latticesemi.com/ |
| 10 | |
| 11 | Author: Scott Kanowitz <scott.kanowitz@gmail.com> |
| 12 | |
| 13 | Description |
| 14 | ----------- |
| 15 | |
| 16 | This driver supports the Lattice POWR1220AT8 chip. The POWR1220 |
| 17 | includes voltage monitoring for 14 inputs as well as trim settings |
| 18 | for output voltages and GPIOs. This driver implements the voltage |
| 19 | monitoring portion of the chip. |
| 20 | |
| 21 | Voltages are sampled by a 12-bit ADC with a step size of 2 mV. |
| 22 | An in-line attenuator allows measurements from 0 to 6 V. The |
| 23 | attenuator is enabled or disabled depending on the setting of the |
| 24 | input's max value. The driver will enable the attenuator for any |
| 25 | value over the low measurement range maximum of 2 V. |
| 26 | |
| 27 | The input naming convention is as follows: |
| 28 | |
| 29 | driver name pin name |
| 30 | in0 VMON1 |
| 31 | in1 VMON2 |
| 32 | in2 VMON3 |
| 33 | in2 VMON4 |
| 34 | in4 VMON5 |
| 35 | in5 VMON6 |
| 36 | in6 VMON7 |
| 37 | in7 VMON8 |
| 38 | in8 VMON9 |
| 39 | in9 VMON10 |
| 40 | in10 VMON11 |
| 41 | in11 VMON12 |
| 42 | in12 VCCA |
| 43 | in13 VCCINP |
| 44 | |
| 45 | The ADC readings are updated on request with a minimum period of 1s. |