[PATCH 1/5] dt-bindings: clock: qcom: Add bindings for PDM GP_MN clock divider

[Taniya Das]

Add device tree bindings for the Qualcomm Peripheral Web's PDM GP_MN
clock divider. The hardware generates a fractional output frequency
from a fixed input clock (typically TCXO4) using the relation
Fout = Fin * (M / N), with duty cycle controlled by a separate D
register. The clock output is routed over a gpio controlled pin.

Signed-off-by: Taniya Das <taniya.das@xxxxxxxxxxxxxxxx>
---
 .../devicetree/bindings/clock/qcom,clk-gp-mnd.yaml | 105 +++++++++++++++++++++
 1 file changed, 105 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/qcom,clk-gp-mnd.yaml b/Documentation/devicetree/bindings/clock/qcom,clk-gp-mnd.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..c1688bb3d68d8d476a8d498aa2774606b8b26018
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/qcom,clk-gp-mnd.yaml
@@ -0,0 +1,105 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/qcom,clk-gp-mnd.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Peripheral Web's PDM GP_MN Clock Divider
+
+maintainers:
+  - Taniya Das <taniya.das@xxxxxxxxxxxxxxxx>
+
+description: |
+  The Peripheral Web's PDM GP_MN clock divider receives an input clock
+  (TCXO4) with frequency Fin and generates an output clock with
+  frequency Fout = Fin * (M / N) and a duty cycle controlled by D
+  and routed over a gpio pin.
+
+  The divider is configured using three registers:
+
+  - GP_MN_CLK_MDIV: holds the M value.
+  - GP_MN_CLK_NDIV: holds the ones complement of (N - M).
+  - GP_MN_CLK_DUTY: holds the D value.
+
+  For every N input clock cycles the GP_MN produces M output clock
+  cycles. D is the number of native clock cycles in which the GP_MN
+  output is low, counted over 2^13 native clock cycles.
+
+  Hardware constraints:
+
+    M <= 511
+    N <= 8191
+    N > 2 * M
+    M < D < (N - M)
+    M and N must be coprime (no common divisor)
+
+properties:
+  compatible:
+    const: qcom,clk-gp-mnd
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: PDM XO4 source clock
+      - description: PDM AHB bus clock for register access
+
+  clock-names:
+    items:
+      - const: pdm_clk
+      - const: ahb_clk
+
+  '#clock-cells':
+    const: 0
+
+  clock-output-names:
+    maxItems: 1
+
+  pinctrl-0:
+    description: Pin configuration for the GP_MN output in the active state.
+
+  pinctrl-names:
+    items:
+      - const: active
+
+  assigned-clocks:
+    maxItems: 1
+    description: Parent clock phandle used to set the input frequency.
+
+  assigned-clock-rates:
+    maxItems: 1
+    description: |
+      Rate for the parent clock in Hz.
+      Supported rates: 19200000, 9600000, 6400000, 4800000.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - '#clock-cells'
+  - clock-output-names
+  - pinctrl-0
+  - pinctrl-names
+  - assigned-clocks
+  - assigned-clock-rates
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/qcom,gcc-sdm845.h>
+    gp_mn: clock-controller@88d3000 {
+        compatible = "qcom,clk-gp-mnd";
+        reg = <0x88d3000 0xc>;
+        clocks = <&gcc GCC_PDM_XO4_CLK>,
+                 <&gcc GCC_PDM_AHB_CLK>;
+        clock-names = "pdm_clk", "ahb_clk";
+        clock-output-names = "gp_mn_clk";
+        pinctrl-0 = <&gp_mn_pin_active>;
+        pinctrl-names = "active";
+        assigned-clocks = <&gcc GCC_PDM_XO4_CLK>;
+        assigned-clock-rates = <4800000>;
+        #clock-cells = <0>;
+    };

-- 
2.34.1