dt-bindings: Add device-tree bindings for CNSS2 driver

* Qualcomm Technologies, Inc. ConNectivity SubSystem Platform Driver

This platform driver adds support for the CNSS subsystem used for PCIe

based Wi-Fi devices. It also adds support to integrate PCIe WLAN module

to subsystem restart framework. Apart from that, it also manages the

3.3V voltage regulator, WLAN Enable GPIO signal and PCIe link dynamically

with support for suspend and resume by retaining the PCI config space

states when PCIe link is shutdown. The main purpose of this device tree

entry below is to invoke the CNSS platform driver and provide handle to

the WLAN enable GPIO, 3.3V fixed voltage regulator resources. It also

provides the reserved RAM dump memory location and size.

Required properties:

  - compatible: "qcom,cnss" for QCA6174 device

                "qcom,cnss-qca6290" for QCA6290 device

                "qcom,cnss-qca6390" for QCA6390 device

                "qcom,cnss-qca6490" for QCA6490 device

  - wlan-en-gpio: WLAN_EN GPIO signal specified by the chip specifications

  - vdd-wlan-supply: phandle to the regulator device tree node

  - pinctrl-names: Names corresponding to the numbered pinctrl states

  - pinctrl-<n>: Pinctrl states as described in

                 bindings/pinctrl/pinctrl-bindings.txt

  - qcom,wlan-rc-num: PCIe root complex number which WLAN chip is attached to

Optional properties:

  - qcom,notify-modem-status: Boolean property to decide whether modem

                              notification should be enabled or not in this

                              platform

  - wlan-soc-swreg-supply: phandle to the external 1.15V regulator for QCA6174

  - wlan-ant-switch-supply: phandle to the 2.7V regulator for the antenna

                            switch of QCA6174

  - qcom,wlan-uart-access: Boolean property to decide whether QCA6174

                           has exclusive access to UART.

  - vdd-wlan-io-supply: phandle to the 1.8V IO regulator for QCA6174

  - vdd-wlan-xtal-supply: phandle to the 1.8V XTAL regulator for QCA6174

  - vdd-wlan-xtal-aon-supply: phandle to the LDO-4 regulator. This is needed

                              on platforms where XTAL regulator depends on

                              always on regulator in VDDmin.

  - vdd-wlan-ctrl1-supply: phandle to the DBU1 - 1.8V for QCA6595 or 3.3V for

                           QCA6174 on auto platform.

  - vdd-wlan-ctrl2-supply: phandle to the DBU4 - 2.2V for QCA6595 or 3.85V for

                           QCA6696 on auto platform.

  - vdd-wlan-core-supply: phandle to the 1.3V CORE regulator for QCA6174

  - vdd-wlan-sp2t-supply: phandle to the 2.7V SP2T regulator for QCA6174

  - <supply-name>-supply: phandle to the regulator device tree node.

                          optional "supply-name" is "vdd-wlan-rfa"

  - qcom,<supply>-config: Specifies voltage levels for supply. Should specified

                          in pairs (min, max), units uV.  There can be optional

                          load in uA and Regulator settle delay in us

  - qcom,smmu-s1-enable: Boolean property to decide whether to enable SMMU

                         S1 stage or not

  - qcom,wlan-smmu-iova-address: I/O virtual address range as <start length>

                                 format to be used for allocations associated

                                 between WLAN/PCIe and SMMU

  - qcom,wlan-ramdump-dynamic: To enable CNSS RAMDUMP collection

                               by providing the size of CNSS DUMP

  - qcom,cmd_db_name: CommandDB name indicating the PMIC rail used for open

                      loop CPR

  - reg: Memory regions defined as starting address and size

  - reg-names: Names of the memory regions defined in reg entry

  - wlan-bootstrap-gpio: WLAN_BOOTSTRAP GPIO signal specified by QCA6174

                         which should be drived depending on platforms

  - qcom,is-dual-wifi-enabled: Boolean property to control wlan enable(wlan-en)

                               gpio on dual-wifi platforms.

  - vdd-wlan-en-supply: WLAN_EN fixed regulator specified by QCA6174

                        specifications.

  - qcom,wlan-en-vreg-support: Boolean property to decide the whether the

                               WLAN_EN pin is a gpio or fixed regulator.

  - qcom,mhi: phandle to indicate the device which needs MHI support.

  - qcom,cap-tsf-gpio: WLAN_TSF_CAPTURED GPIO signal specified by the chip

                       specifications, should be drived depending on products

Example:

    qcom,cnss@0d400000 {

        compatible = "qcom,cnss";

        reg = <0x0d400000 0x200000>;

        reg-names = "ramdump";

        qcom,wlan-ramdump-dynamic = <0x200000>;

        wlan-en-gpio = <&msmgpio 82 0>;

        vdd-wlan-supply = <&wlan_vreg>;

        qcom,notify-modem-status;

        wlan-soc-swreg-supply = <&pma8084_l27>;

        pinctrl-names = "default";

        pinctrl-0 = <&cnss_default>;

        qcom,wlan-rc-num = <0>;

        qcom,wlan-smmu-iova-address = <0 0x10000000>;

        qcom,mhi = <&mhi_wlan>;

        qcom,cap-tsf-gpio = <&tlmm 126 1>;

    };