| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | Freescale mx25 TS conversion queue module |
| 2 | |
| 3 | mx25 touchscreen conversion queue module which controls the ADC unit of the |
| 4 | mx25 for attached touchscreens. |
| 5 | |
| 6 | Required properties: |
| 7 | - compatible: Should be "fsl,imx25-tcq". |
| 8 | - reg: Memory range of the device. |
| 9 | - interrupts: Should be the interrupt number associated with this module within |
| 10 | the tscadc unit (<0>). |
| 11 | - fsl,wires: Should be '<4>' or '<5>' |
| 12 | |
| 13 | Optional properties: |
| 14 | - fsl,pen-debounce-ns: Pen debounce time in nanoseconds. |
| 15 | - fsl,pen-threshold: Pen-down threshold for the touchscreen. This is a value |
| 16 | between 1 and 4096. It is the ratio between the internal reference voltage |
| 17 | and the measured voltage after the plate was precharged. Resistance between |
| 18 | plates and therefore the voltage decreases with pressure so that a smaller |
| 19 | value is equivalent to a higher pressure. |
| 20 | - fsl,settling-time-ns: Settling time in nanoseconds. The settling time is before |
| 21 | the actual touch detection to wait for an even charge distribution in the |
| 22 | plate. |
| 23 | |
| 24 | This device includes two conversion queues which can be added as subnodes. |
| 25 | The first queue is for the touchscreen, the second for general purpose ADC. |
| 26 | |
| 27 | Example: |
| 28 | tsc: tcq@50030400 { |
| 29 | compatible = "fsl,imx25-tcq"; |
| 30 | reg = <0x50030400 0x60>; |
| 31 | interrupt-parent = <&tscadc>; |
| 32 | interrupts = <0>; |
| 33 | fsl,wires = <4>; |
| 34 | }; |