xref: /kernel/linux/linux-5.10/Documentation/devicetree/bindings/phy/phy-miphy28lp.txt

STMicroelectronics STi MIPHY28LP PHY binding
============================================

This binding describes a miphy device that is used to control PHY hardware
for SATA, PCIe or USB3.

Required properties (controller (parent) node):
- compatible	: Should be "st,miphy28lp-phy".
- st,syscfg	: Should be a phandle of the system configuration register group
		  which contain the SATA, PCIe or USB3 mode setting bits.

Required nodes	:  A sub-node is required for each channel the controller
		   provides. Address range information including the usual
		   'reg' and 'reg-names' properties are used inside these
		   nodes to describe the controller's topology. These nodes
		   are translated by the driver's .xlate() function.

Required properties (port (child) node):
- #phy-cells	: Should be 1 (See second example)
		  Cell after port phandle is device type from:
			- PHY_TYPE_SATA
			- PHY_TYPE_PCI
			- PHY_TYPE_USB3
- reg		: Address and length of the register set for the device.
- reg-names	: The names of the register addresses corresponding to the registers
		  filled in "reg". It can also contain the offset of the system configuration
		  registers used as glue-logic to setup the device for SATA/PCIe or USB3
		  devices.
- st,syscfg	: Offset of the parent configuration register.
- resets	: phandle to the parent reset controller.
- reset-names	: Associated name must be "miphy-sw-rst".

Optional properties (port (child) node):
- st,osc-rdy		: to check the MIPHY0_OSC_RDY status in the glue-logic. This
			  is not available in all the MiPHY. For example, for STiH407, only the
			  MiPHY0 has this bit.
- st,osc-force-ext	: to select the external oscillator. This can change from
			  different MiPHY inside the same SoC.
- st,sata_gen		: to select which SATA_SPDMODE has to be set in the SATA system config
			  register.
- st,px_rx_pol_inv	: to invert polarity of RXn/RXp (respectively negative line and positive
			  line).
- st,scc-on		: enable ssc to reduce effects of EMI (only for sata or PCIe).
- st,tx-impedance-comp	: to compensate tx impedance avoiding out of range values.

example:

		miphy28lp_phy: miphy28lp@9b22000 {
			compatible = "st,miphy28lp-phy";
			st,syscfg = <&syscfg_core>;
			#address-cells	= <1>;
			#size-cells	= <1>;
			ranges;

			phy_port0: port@9b22000 {
				reg = <0x9b22000 0xff>,
				      <0x9b09000 0xff>,
				      <0x9b04000 0xff>;
				reg-names = "sata-up",
					    "pcie-up",
					    "pipew";

				st,syscfg = <0x114 0x818 0xe0 0xec>;
				#phy-cells = <1>;
				st,osc-rdy;
				reset-names = "miphy-sw-rst";
				resets = <&softreset STIH407_MIPHY0_SOFTRESET>;
			};

			phy_port1: port@9b2a000 {
				reg = <0x9b2a000 0xff>,
				      <0x9b19000 0xff>,
				      <0x9b14000 0xff>;
				reg-names = "sata-up",
					    "pcie-up",
					    "pipew";

				st,syscfg = <0x118 0x81c 0xe4 0xf0>;

				#phy-cells = <1>;
				st,osc-force-ext;
				reset-names = "miphy-sw-rst";
				resets = <&softreset STIH407_MIPHY1_SOFTRESET>;
			};

			phy_port2: port@8f95000 {
				reg = <0x8f95000 0xff>,
				      <0x8f90000 0xff>;
				reg-names = "pipew",
					    "usb3-up";

				st,syscfg = <0x11c 0x820>;

				#phy-cells = <1>;
				reset-names = "miphy-sw-rst";
				resets = <&softreset STIH407_MIPHY2_SOFTRESET>;
			};
		};


Specifying phy control of devices
=================================

Device nodes should specify the configuration required in their "phys"
property, containing a phandle to the miphy device node and an index
specifying which configuration to use, as described in phy-bindings.txt.

example:
		sata0: sata@9b20000  {
			...
			phys		= <&phy_port0 PHY_TYPE_SATA>;
			...
		};

Macro definitions for the supported miphy configuration can be found in:

include/dt-bindings/phy/phy.h