dt-bindings: pinctrl: eswin: Document for EIC7700 SoC

Add EIC7700 pinctrl device for all configurable pins.
For the EIC7700 pinctrl registers, each register (32 bits)
controls the characteristics of a single pin.
It supports setting function multiplexing, Schmitt trigger,
drive strength, pull-up/pull-down, and input enable.

Co-developed-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Yulin Lu <luyulin@eswincomputing.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/20250612104811.1206-1-luyulin@eswincomputing.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/eswin,eic7700-pinctrl.yaml

@@ -0,0 +1,156 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/eswin,eic7700-pinctrl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Eswin Eic7700 Pinctrl
+
+maintainers:
+  - Yulin Lu <luyulin@eswincomputing.com>
+
+allOf:
+  - $ref: pinctrl.yaml#
+
+description: |
+  eic7700 pin configuration nodes act as a container for an arbitrary number of
+  subnodes. Each of these subnodes represents some desired configuration for one or
+  more pins. This configuration can include the mux function to select on those pin(s),
+  and various pin configuration parameters, such as input-enable, pull-up, etc.
+
+properties:
+  compatible:
+    const: eswin,eic7700-pinctrl
+
+  reg:
+    maxItems: 1
+
+  vrgmii-supply:
+    description:
+      Regulator supply for the RGMII interface IO power domain.
+      This property should reference a regulator that provides either 1.8V or 3.3V,
+      depending on the board-level voltage configuration required by the RGMII interface.
+
+patternProperties:
+  '-grp$':
+    type: object
+    additionalProperties: false
+
+    patternProperties:
+      '-pins$':
+        type: object
+
+        properties:
+          pins:
+            description:
+              For eic7700, specifies the name(s) of one or more pins to be configured by
+              this node.
+            items:
+              enum: [ chip_mode, mode_set0, mode_set1, mode_set2, mode_set3, xin,
+                      rst_out_n, key_reset_n, gpio0, por_sel, jtag0_tck, jtag0_tms,
+                      jtag0_tdi, jtag0_tdo, gpio5, spi2_cs0_n, jtag1_tck, jtag1_tms,
+                      jtag1_tdi, jtag1_tdo, gpio11, spi2_cs1_n, pcie_clkreq_n,
+                      pcie_wake_n, pcie_perst_n, hdmi_scl, hdmi_sda, hdmi_cec,
+                      jtag2_trst, rgmii0_clk_125, rgmii0_txen, rgmii0_txclk,
+                      rgmii0_txd0, rgmii0_txd1, rgmii0_txd2, rgmii0_txd3, i2s0_bclk,
+                      i2s0_wclk, i2s0_sdi, i2s0_sdo, i2s_mclk, rgmii0_rxclk,
+                      rgmii0_rxdv, rgmii0_rxd0, rgmii0_rxd1, rgmii0_rxd2, rgmii0_rxd3,
+                      i2s2_bclk, i2s2_wclk, i2s2_sdi, i2s2_sdo, gpio27, gpio28, gpio29,
+                      rgmii0_mdc, rgmii0_mdio, rgmii0_intb, rgmii1_clk_125, rgmii1_txen,
+                      rgmii1_txclk, rgmii1_txd0, rgmii1_txd1, rgmii1_txd2, rgmii1_txd3,
+                      i2s1_bclk, i2s1_wclk, i2s1_sdi, i2s1_sdo, gpio34, rgmii1_rxclk,
+                      rgmii1_rxdv, rgmii1_rxd0, rgmii1_rxd1, rgmii1_rxd2, rgmii1_rxd3,
+                      spi1_cs0_n, spi1_clk, spi1_d0, spi1_d1, spi1_d2, spi1_d3, spi1_cs1_n,
+                      rgmii1_mdc, rgmii1_mdio, rgmii1_intb, usb0_pwren, usb1_pwren,
+                      i2c0_scl, i2c0_sda, i2c1_scl, i2c1_sda, i2c2_scl, i2c2_sda,
+                      i2c3_scl, i2c3_sda, i2c4_scl, i2c4_sda, i2c5_scl, i2c5_sda,
+                      uart0_tx, uart0_rx, uart1_tx, uart1_rx, uart1_cts, uart1_rts,
+                      uart2_tx, uart2_rx, jtag2_tck, jtag2_tms, jtag2_tdi, jtag2_tdo,
+                      fan_pwm, fan_tach, mipi_csi0_xvs, mipi_csi0_xhs, mipi_csi0_mclk,
+                      mipi_csi1_xvs, mipi_csi1_xhs, mipi_csi1_mclk, mipi_csi2_xvs,
+                      mipi_csi2_xhs, mipi_csi2_mclk, mipi_csi3_xvs, mipi_csi3_xhs,
+                      mipi_csi3_mclk, mipi_csi4_xvs, mipi_csi4_xhs, mipi_csi4_mclk,
+                      mipi_csi5_xvs, mipi_csi5_xhs, mipi_csi5_mclk, spi3_cs_n, spi3_clk,
+                      spi3_di, spi3_do, gpio92, gpio93, s_mode, gpio95, spi0_cs_n,
+                      spi0_clk, spi0_d0, spi0_d1, spi0_d2, spi0_d3, i2c10_scl,
+                      i2c10_sda, i2c11_scl, i2c11_sda, gpio106, boot_sel0, boot_sel1,
+                      boot_sel2, boot_sel3, gpio111, lpddr_ref_clk ]
+
+          function:
+            description:
+              Specify the alternative function to be configured for the
+              given pins.
+            enum: [ disabled, boot_sel, chip_mode, emmc, fan_tach,
+                    gpio, hdmi, i2c, i2s, jtag, ddr_ref_clk_sel,
+                    lpddr_ref_clk, mipi_csi, osc, pcie, pwm,
+                    rgmii, reset, sata, sdio, spi, s_mode, uart, usb ]
+
+          input-schmitt-enable: true
+
+          input-schmitt-disable: true
+
+          bias-disable: true
+
+          bias-pull-down: true
+
+          bias-pull-up: true
+
+          input-enable: true
+
+          input-disable: true
+
+          drive-strength-microamp: true
+
+        required:
+          - pins
+
+        additionalProperties: false
+
+        allOf:
+          - $ref: pincfg-node.yaml#
+          - $ref: pinmux-node.yaml#
+
+          - if:
+              properties:
+                pins:
+                  anyOf:
+                    - pattern: '^rgmii'
+                    - const: lpddr_ref_clk
+            then:
+              properties:
+                drive-strength-microamp:
+                  enum: [3000, 6000, 9000, 12000, 15000, 18000, 21000, 24000]
+            else:
+              properties:
+                drive-strength-microamp:
+                  enum: [6000, 9000, 12000, 15000, 18000, 21000, 24000, 27000]
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    pinctrl@51600080 {
+      compatible = "eswin,eic7700-pinctrl";
+      reg = <0x51600080 0x1fff80>;
+      vrgmii-supply = <&vcc_1v8>;
+
+      dev-active-grp {
+        /* group node defining 1 standard pin */
+        gpio10-pins {
+          pins = "jtag1_tdo";
+          function = "gpio";
+          input-enable;
+          bias-pull-up;
+        };
+
+        /* group node defining 2 I2C pins */
+        i2c6-pins {
+          pins = "uart1_cts", "uart1_rts";
+          function = "i2c";
+        };
+      };
+    };