[PATCH v4 1/3] dt-bindings: mmc: Document the Amlogic Meson SDHC MMC host controller

[Martin Blumenstingl]

This documents the devicetree bindings for the SDHC MMC host controller
found in Meson6, Meson8, Meson8b and Meson8m2 SoCs. It can use a
bus-width of 1/4/8-bit and it supports eMMC spec 4.4x/4.5x including
HS200 mode (up to 100MHz clock). It embeds an internal clock controller
which outputs four clocks (mod_clk, sd_clk, tx_clk and rx_clk) and is
fed by four external input clocks (clkin[0-3]). "pclk" is the module
register clock, it has to be enabled to access the registers.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
---
 .../bindings/mmc/amlogic,meson-mx-sdhc.yaml   | 83 +++++++++++++++++++
 .../dt-bindings/clock/meson-mx-sdhc-clkc.h    |  8 ++
 2 files changed, 91 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mmc/amlogic,meson-mx-sdhc.yaml
 create mode 100644 include/dt-bindings/clock/meson-mx-sdhc-clkc.h

diff --git a/Documentation/devicetree/bindings/mmc/amlogic,meson-mx-sdhc.yaml b/Documentation/devicetree/bindings/mmc/amlogic,meson-mx-sdhc.yaml
new file mode 100644
index 000000000000..74632692ce26
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/amlogic,meson-mx-sdhc.yaml
@@ -0,0 +1,83 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mmc/amlogic,meson-mx-sdhc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Amlogic Meson SDHC controller Device Tree Bindings
+
+allOf:
+  - $ref: "mmc-controller.yaml"
+
+maintainers:
+  - Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
+
+description: |
+  The SDHC MMC host controller on Amlogic SoCs provides an eMMC and MMC
+  card interface with 1/4/8-bit bus width.
+  It supports eMMC spec 4.4x/4.5x including HS200 (up to 100MHz clock).
+
+properties:
+  compatible:
+    items:
+      - enum:
+        - amlogic,meson8-sdhc
+        - amlogic,meson8b-sdhc
+        - amlogic,meson8m2-sdhc
+      - const: amlogic,meson-mx-sdhc
+
+  reg:
+    minItems: 1
+
+  interrupts:
+    minItems: 1
+
+  "#clock-cells":
+    const: 1
+
+  clocks:
+    minItems: 9
+
+  clock-names:
+    items:
+      - const: pclk
+      - const: mod_clk
+      - const: sd_clk
+      - const: rx_clk
+      - const: tx_clk
+      - const: clkin0
+      - const: clkin1
+      - const: clkin2
+      - const: clkin3
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - "#clock-cells"
+  - clocks
+  - clock-names
+
+examples:
+  - |
+    #include <dt-bindings/clock/meson-mx-sdhc-clkc.yaml>;
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    sdhc: mmc@8e00 {
+      compatible = "amlogic,meson8-sdhc", "amlogic,meson-mx-sdhc";
+      reg = <0x8e00 0x42>;
+      interrupts = <GIC_SPI 78 IRQ_TYPE_EDGE_RISING>;
+      #clock-cells = <1>;
+      clocks = <&sdhc_pclk>,
+               <&sdhc SDHC_CLKID_MOD_CLK>,
+               <&sdhc SDHC_CLKID_SD_CLK>,
+               <&sdhc SDHC_CLKID_TX_CLK>,
+               <&sdhc SDHC_CLKID_RX_CLK>,
+               <&xtal>,
+               <&fclk_div4>,
+               <&fclk_div3>,
+               <&fclk_div5>;
+      clock-names = "pclk", "mod_clk", "sd_clk", "tx_clk", "rx_clk",
+                    "clkin0", "clkin1", "clkin2", "clkin3";
+    };
diff --git a/include/dt-bindings/clock/meson-mx-sdhc-clkc.h b/include/dt-bindings/clock/meson-mx-sdhc-clkc.h
new file mode 100644
index 000000000000..ad9f6e4dc426
--- /dev/null
+++ b/include/dt-bindings/clock/meson-mx-sdhc-clkc.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#define SDHC_CLKID_SRC_SEL	0
+#define SDHC_CLKID_DIV		1
+#define SDHC_CLKID_MOD_CLK	2
+#define SDHC_CLKID_SD_CLK	3
+#define SDHC_CLKID_TX_CLK	4
+#define SDHC_CLKID_RX_CLK	5
-- 
2.24.1