| QPNP LCDB (LCD Bias) Regulator |
| |
| QPNP LCDB module provides voltage bias to the LCD display panel. The biases |
| are positive (VDISP - supported by LDO) and negative (VDISN - supported by |
| NCP) voltage signals. The module also supports TTW (touch-to-wake) capability. |
| |
| This document describes the bindings for QPNP LCDB module. |
| |
| ======================= |
| Required Node Structure |
| ======================= |
| |
| LCDB module must be described in two level of device nodes. |
| |
| ============================== |
| First Level Node - LCDB module |
| ============================== |
| |
| - compatible |
| Usage: required |
| Value type: <string> |
| Definition: should be "qcom,qpnp-lcdb-regulator" |
| |
| - reg |
| Usage: required |
| Value type: <prop-encoded-array> |
| Definition: Base address of the LCDB SPMI peripheral. |
| |
| - qcom,pmic-revid |
| Usage: required |
| Value type: <phandle> |
| Definition: Phandle to the PMIC's revid node |
| |
| - qcom,voltage-step-ramp |
| Usage: optional |
| Value type: <bool> |
| Definition: Required only if the voltage needs to be set in the |
| steps of 500 mV starting from the 4500 mV. This needs |
| to be enabled only on platforms where voltage needs to |
| be ramped up with multiple steps. |
| |
| - qcom,pwrdn-delay-ms |
| Usage: optional |
| Value type: <u32> |
| Definition: Required to control the LDO power down delay. |
| Possible values are 0, 1, 4, 8. |
| |
| Touch-to-wake (TTW) properties: |
| |
| TTW supports 2 modes of operation - HW and SW. In the HW mode the enable/disable |
| logic is controlled by an external signal (pin) where as in the SW mode it is |
| is controlled by a pre-configured timer (ton/toff) programmed in the TTW |
| register. |
| |
| Properties below are specific to TTW mode only. They are sepecified in the |
| main node. |
| |
| - qcom,ttw-enable |
| Usage: optional |
| Value type: <bool> |
| Definition: Touch to wake-up support enabled. |
| |
| - qcom,ttw-mode-sw |
| Usage: optional |
| Value type: <bool> |
| Definition: Touch to wake supported in SW mode. |
| If not defined, ttw is enabled by HW pin. |
| |
| - qcom,attw-toff-ms |
| Usage: required if 'qcom,ttw-mode-sw' is true. |
| Value type: <bool> |
| Definition: Off time (in mS) for the VDISP/VDISN signals. |
| Possible values are 4, 8, 16, 32. |
| |
| - qcom,attw-ton-ms |
| Usage: required if 'qcom,ttw-mode-sw' is true. |
| Value type: <bool> |
| Definition: ON time (in mS) for the VDISP/VDISN signals. |
| Possible values are 4, 8, 16, 32. |
| |
| ======================================== |
| Second Level Nodes - LDO/NCP/BOOST block |
| ======================================== |
| |
| LDO / NCP subnode common properties: |
| |
| Properties below are common to the LDO and NCP bias. |
| |
| - label |
| Usage: required |
| Value type: <string> |
| Definition: A string used to describe the bias type. |
| Possible values are ldo, ncp, bst. |
| |
| - regulator-name |
| Usage: required |
| Value type: <string> |
| Definition: A string used to describe the regulator. |
| |
| - regulator-min-microvolt |
| Usage: required |
| Value type: <u32> |
| Definition: Minimum voltage (in uV) supported by the bias. |
| |
| - regulator-max-microvolt |
| Usage: required |
| Value type: <u32> |
| Definition: Maximum voltage (in uV) supported by the bias. |
| |
| |
| LDO subnode properties: |
| |
| Properties below are specific to LDO bias only. |
| |
| - qcom,ldo-voltage-mv |
| Usage: optional |
| Value type: <u32> |
| Definition: Voltage (in mV) progammed for the LDO (VDISP). |
| Possile values are 4000mV to 6000mV. The range |
| 4000mV to 4900mV is in 100mV steps and 4900mV to |
| 6000mV is in 50mV steps. |
| |
| - qcom,ldo-pd |
| Usage: optional |
| Value type: <u32> |
| Definition: Pull-down configuration of LDO. Possible values are: |
| 1 - Enable pull-down |
| 0 - Disable pull-down |
| |
| - qcom,ldo-pd-strength |
| Usage: optional |
| Value type: <u32> |
| Definition: Pull-down strength. Possible values are: |
| 0 - Weak pull-down |
| 1 - Strong pull-down |
| |
| - qcom,ldo-ilim-ma |
| Usage: optional |
| Value type: <u32> |
| Definition: Current limit (in mA) of the LDO bias. |
| Possible values are 110, 160, 210, 260, 310, 360, 410, 460. |
| |
| - qcom,ldo-soft-start-us |
| Usage: optional |
| Value type: <u32> |
| Definition: Soft-start time (in uS) of the LDO bias. |
| Possible values are 0, 500, 1000, 2000. |
| |
| |
| NCP subnode properties: |
| |
| Properties below are specific to NCP bias only. |
| |
| - qcom,ncp-voltage-mv |
| Usage: optional |
| Value type: <u32> |
| Definition: Voltage (in mV) progammed for the NCP (VDISN). |
| Possile values are 4000mV to 6000mV. The range |
| 4000mV to 4900mV is in 100mV steps and 4900mV to |
| 6000mV is in 50mV steps. |
| |
| - qcom,ncp-pd |
| Usage: optional |
| Value type: <u32> |
| Definition: Pull-down configuration of NCP. Possible values are: |
| 1 - Enable pull-down |
| 0 - Disable pull-down |
| |
| - qcom,ncp-pd-strength |
| Usage: optional |
| Value type: <u32> |
| Definition: Pull-down strength. Possible values are: |
| 0 - Weak pull-down |
| 1 - Strong pull-down |
| |
| - qcom,ncp-ilim-ma |
| Usage: optional |
| Value type: <u32> |
| Definition: Current limit (in mA) of the NCP bias. |
| Possible values are 260, 460, 640, 810. |
| |
| - qcom,ncp-soft-start-us |
| Usage: optional |
| Value type: <u32> |
| Definition: Soft-start time (in uS) of the NCP bias. |
| Possible values are 0, 500, 1000, 2000. |
| |
| |
| BOOST subnode properties: |
| |
| Properties below are specific to BOOST subnode only. |
| |
| - qcom,bst-pd |
| Usage: optional |
| Value type: <bool> |
| Definition: Pull-down configuration of BOOST. Possible values are: |
| 1 - Enable pull-down |
| 0 - Disable pull-down |
| |
| - qcom,bst-pd-strength |
| Usage: optional |
| Value type: <u32> |
| Definition: Pull-down strength. Possible values are: |
| 0 - Weak pull-down |
| 1 - Strong pull-down |
| |
| - qcom,bst-ps |
| Usage: optional |
| Value type: <u32> |
| Definition: Pulse-skip configuration for boost. Possible values are: |
| 1 - Enable Pulse-skip |
| 0 - Disable Pulse-skip |
| |
| - qcom,bst-ps-threshold-ma |
| Usage: optional |
| Value type: <u32> |
| Definition: Current threshold (in mA) at which pulse-skip is entered. |
| Possible values are 50, 60, 70, 80. |
| |
| - qcom,bst-ilim-ma |
| Usage: optional |
| Value type: <u32> |
| Definition: Current limit (in mA) of the BOOST rail. |
| Possible values are 200 to 1600mA in 200mA steps. |
| |
| - qcom,bst-headroom-mv |
| Usage: optional |
| Value type: <u16> |
| Definition: Headroom of the boost (in mV). If not specified, then the |
| default value is 200 mV (PM660L) or 150 mV (for PM855L or |
| PMI632). |
| |
| ======= |
| Example |
| ======= |
| |
| pm660l_lcdb: qpnp-lcdb@ec00 { |
| compatible = "qcom,qpnp-lcdb-regulator"; |
| #address-cells = <1>; |
| #size-cells = <1>; |
| reg = <0xec00 0x100>; |
| |
| qcom,ttw-enable; |
| |
| lcdb_ldo_vreg: ldo { |
| label = "ldo"; |
| regulator-name = "lcdb_ldo"; |
| regulator-min-microvolt = <4000000>; |
| regulator-max-microvolt = <6000000>; |
| |
| qcom,ldo-voltage-mv = <5400>; |
| qcom,ldo-pd = <1>; |
| qcom,ldo-pd-strength = <1>; |
| }; |
| |
| lcdb_ncp_vreg: ncp { |
| label = "ncp"; |
| regulator-name = "lcdb_ncp"; |
| regulator-min-microvolt = <4000000>; |
| regulator-max-microvolt = <6000000>; |
| |
| qcom,ncp-voltage-mv = <5400>; |
| qcom,ncp-pd = <1>; |
| qcom,ncp-pd-strength = <1>; |
| }; |
| |
| lcdb_bst: bst { |
| label = "bst"; |
| |
| qcom,bst-pd = <1>; |
| qcom,bst-pd-strength = <1>; |
| qcom,bst-ps = <1>; |
| qcom,bst-ps-threshold-ma = <50>; |
| qcom,bst-headroom-mv = <200>; |
| }; |
| }; |