Document Rockchip UFS host controller for RK3576 SoC.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

---

Changes in v3:
- rename the file to rockchip,rk3576-ufshc.yaml
- add description for reset-gpios
- use rockchip,rk3576-ufshc as compatible

Changes in v2:
- rename the file
- add reset-gpios

 .../bindings/ufs/rockchip,rk3576-ufshc.yaml        | 103 +++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/ufs/rockchip,rk3576-ufshc.yaml

diff --git a/Documentation/devicetree/bindings/ufs/rockchip,rk3576-ufshc.yaml b/Documentation/devicetree/bindings/ufs/rockchip,rk3576-ufshc.yaml
new file mode 100644
index 0000000..1c78ea5
--- /dev/null
+++ b/Documentation/devicetree/bindings/ufs/rockchip,rk3576-ufshc.yaml
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ufs/rockchip,rk3576-ufshc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Rockchip UFS Host Controller
+
+maintainers:
+  - Shawn Lin <shawn.lin@rock-chips.com>
+
+allOf:
+  - $ref: ufs-common.yaml
+
+properties:
+  compatible:
+    const: rockchip,rk3576-ufshc
+
+  reg:
+    maxItems: 5
+
+  reg-names:
+    items:
+      - const: hci
+      - const: mphy
+      - const: hci_grf
+      - const: mphy_grf
+      - const: hci_apb
+
+  clocks:
+    maxItems: 4
+
+  clock-names:
+    items:
+      - const: core
+      - const: pclk
+      - const: pclk_mphy
+      - const: ref_out
+
+  power-domains:
+    maxItems: 1
+
+  resets:
+    maxItems: 4
+
+  reset-names:
+    items:
+      - const: biu
+      - const: sys
+      - const: ufs
+      - const: grf
+
+  reset-gpios:
+    maxItems: 1
+    description: |
+      GPIO specifiers for host to reset the device.
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - clocks
+  - clock-names
+  - interrupts
+  - power-domains
+  - resets
+  - reset-names
+  - reset-gpios
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/rockchip,rk3576-cru.h>
+    #include <dt-bindings/reset/rockchip,rk3576-cru.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/power/rockchip,rk3576-power.h>
+    #include <dt-bindings/pinctrl/rockchip.h>
+    #include <dt-bindings/gpio/gpio.h>
+
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        ufs: ufs@2a2d0000 {
+              compatible = "rockchip,rk3576-ufshc";
+              reg = <0x0 0x2a2d0000 0x0 0x10000>,
+                    <0x0 0x2b040000 0x0 0x10000>,
+                    <0x0 0x2601f000 0x0 0x1000>,
+                    <0x0 0x2603c000 0x0 0x1000>,
+                    <0x0 0x2a2e0000 0x0 0x10000>;
+              reg-names = "hci", "mphy", "hci_grf", "mphy_grf", "hci_apb";
+              clocks = <&cru ACLK_UFS_SYS>, <&cru PCLK_USB_ROOT>, <&cru PCLK_MPHY>,
+                      <&cru CLK_REF_UFS_CLKOUT>;
+              clock-names = "core", "pclk", "pclk_mphy", "ref_out";
+              interrupts = <GIC_SPI 361 IRQ_TYPE_LEVEL_HIGH>;
+              power-domains = <&power RK3576_PD_USB>;
+              resets = <&cru SRST_A_UFS_BIU>, <&cru SRST_A_UFS_SYS>, <&cru SRST_A_UFS>,
+                        <&cru SRST_P_UFS_GRF>;
+              reset-names = "biu", "sys", "ufs", "grf";
+              reset-gpios = <&gpio4 RK_PD0 GPIO_ACTIVE_LOW>;
+        };
+    };
-- 
2.7.4

On Tue, Oct 08, 2024 at 02:15:27PM +0800, Shawn Lin wrote:
> Document Rockchip UFS host controller for RK3576 SoC.
> 
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> 
> ---
> 
> Changes in v3:
> - rename the file to rockchip,rk3576-ufshc.yaml
> - add description for reset-gpios
> - use rockchip,rk3576-ufshc as compatible

... 

> +  power-domains:
> +    maxItems: 1
> +
> +  resets:
> +    maxItems: 4
> +
> +  reset-names:
> +    items:
> +      - const: biu
> +      - const: sys
> +      - const: ufs
> +      - const: grf
> +
> +  reset-gpios:
> +    maxItems: 1
> +    description: |
> +      GPIO specifiers for host to reset the device.

Redundant description. I don't get why did you add it.... maybe we were
confused by duplicating resets and GPIO, but then say here something
useful not what the property name is already saying.

E.g. Which pin is this? Active low/high? Resets which device - phy?
memory?

With proper description:

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof