dt-bindings: ufs: Add bindings for Samsung ufs host

This patch adds DT bindings for Samsung ufs hci
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Link: https://lore.kernel.org/r/20210915111844.42752-1-chanho61.park@samsung.comSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ufs/samsung,exynos-ufs.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung SoC series UFS host controller Device Tree Bindings
+
+maintainers:
+  - Alim Akhtar <alim.akhtar@samsung.com>
+
+description: |
+  Each Samsung UFS host controller instance should have its own node.
+  This binding define Samsung specific binding other then what is used
+  in the common ufshcd bindings
+  [1] Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
+
+properties:
+
+  compatible:
+    enum:
+      - samsung,exynos7-ufs
+
+  reg:
+    items:
+      - description: HCI register
+      - description: vendor specific register
+      - description: unipro register
+      - description: UFS protector register
+
+  reg-names:
+    items:
+      - const: hci
+      - const: vs_hci
+      - const: unipro
+      - const: ufsp
+
+  clocks:
+    items:
+      - description: ufs link core clock
+      - description: unipro main clock
+
+  clock-names:
+    items:
+      - const: core_clk
+      - const: sclk_unipro_main
+
+  interrupts:
+    maxItems: 1
+
+  phys:
+    maxItems: 1
+
+  phy-names:
+    const: ufs-phy
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - phys
+  - phy-names
+  - clocks
+  - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/exynos7-clk.h>
+
+    ufs: ufs@15570000 {
+       compatible = "samsung,exynos7-ufs";
+       reg = <0x15570000 0x100>,
+             <0x15570100 0x100>,
+             <0x15571000 0x200>,
+             <0x15572000 0x300>;
+       reg-names = "hci", "vs_hci", "unipro", "ufsp";
+       interrupts = <GIC_SPI 200 IRQ_TYPE_LEVEL_HIGH>;
+       clocks = <&clock_fsys1 ACLK_UFS20_LINK>,
+                <&clock_fsys1 SCLK_UFSUNIPRO20_USER>;
+       clock-names = "core_clk", "sclk_unipro_main";
+       pinctrl-names = "default";
+       pinctrl-0 = <&ufs_rst_n &ufs_refclk_out>;
+       phys = <&ufs_phy>;
+       phy-names = "ufs-phy";
+    };
+...