[PATCH/RFC v3 0/3] clk: shmobile: Add new Renesas CPG/MSSR DT bindings

[PATCH/RFC v3 0/3] clk: shmobile: Add new Renesas CPG/MSSR DT bindings

[Geert Uytterhoeven]

	Hi Mike, Stephen, et al.,

As discussed at ELCE last week, here's my RFC introducing a new unified
binding for the Renesas CPG (Clock Pulse Generator) and MSSR (Module
Standby and Software Reset) blocks.  These bindings are supposed to be
more in-line with current CCF best practices, and allow expansion to
cover the module reset functionality in the future.  They are intended
to be used initially for the new R-Car Gen3 SoCs (r8a7795), but we may
decide to migrate older SoCs somewhen in the future.

  - The first patch is an RFC introducing the new bindings.
  - Patches 2 and 3 are Proof-of-Concepts of the CPG Core Clock
    Definitions for the already supported R-Car M2-W (r8a7791) SoC, and
    for the new R-Car H3 (r8a7795) SoC.

The idea is to get the bindings (for r8a7795) accepted in v4.4, so we
can continue developing and prepare final support for r8a7795 in v4.5.

I will post preliminary code and DT patches for both r8a7791 (POC) and
r8a7795 (mandatory) as soon as possible.

Thanks for your comments!

References:
  - v2+ ≈ [PATCH v8 00/05] Renesas R-Car Gen3 CPG support V8"
    (http://www.spinics.net/lists/linux-clk/msg03288.html)
  - v2 = "[PATCH/RFC v2 0/4] Renesas CPG/MSTP DT Binding Proposal"
    (http://www.spinics.net/lists/linux-clk/msg03132.html)
  - v1 = "Renesas CPG/MSTP DT Binding Proposal"
    (http://www.spinics.net/lists/linux-clk/msg01189.html)

Geert Uytterhoeven (3):
  [RFC] clk: shmobile: Add new Renesas CPG/MSSR DT bindings
  [POC] clk: shmobile: Add r8a7791 CPG Core Clock Definitions
  [POC] clk: shmobile: Add r8a7795 CPG Core Clock Definitions

 .../devicetree/bindings/clock/renesas,cpg-mssr.txt | 71 ++++++++++++++++++++++
 include/dt-bindings/clock/r8a7791-cpg-mssr.h       | 22 +++++++
 include/dt-bindings/clock/r8a7795-cpg-mssr.h       | 17 ++++++
 include/dt-bindings/clock/renesas-cpg-mssr.h       | 15 +++++
 4 files changed, 125 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/renesas,cpg-mssr.txt
 create mode 100644 include/dt-bindings/clock/r8a7791-cpg-mssr.h
 create mode 100644 include/dt-bindings/clock/r8a7795-cpg-mssr.h
 create mode 100644 include/dt-bindings/clock/renesas-cpg-mssr.h

-- 
1.9.1

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

[PATCH/RFC v3 1/3] clk: shmobile: Add new Renesas CPG/MSSR DT bindings

[Geert Uytterhoeven]

On Renesas ARM SoCs (SH/R-Mobile, R-Car, RZ), the CPG (Clock Pulse
Generator) and MSSR (Module Standby and Software Reset) blocks are
intimately connected, and share the same register block.

Hence it makes sense to describe these two blocks using a
single device node in DT, instead of using a hierarchical structure with
multiple nodes, using a mix of generic and SoC-specific bindings.

These new DT bindings are intended to replace the existing DT bindings
for CPG core clocks ("renesas,*-cpg-clocks", "renesas,cpg-div6-clock")
and module clocks ("renesas,*-mstp-clocks"), at least for new SoCs.

This will make it easier to add module reset support later, which is
currently not implemented, and difficult to achieve using the existing
bindings due to the intertwined register layout.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 .../devicetree/bindings/clock/renesas,cpg-mssr.txt | 71 ++++++++++++++++++++++
 include/dt-bindings/clock/renesas-cpg-mssr.h       | 15 +++++
 2 files changed, 86 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/renesas,cpg-mssr.txt
 create mode 100644 include/dt-bindings/clock/renesas-cpg-mssr.h

diff --git a/Documentation/devicetree/bindings/clock/renesas,cpg-mssr.txt b/Documentation/devicetree/bindings/clock/renesas,cpg-mssr.txt
new file mode 100644
index 0000000000000000..a56836aa2131a8db
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/renesas,cpg-mssr.txt
@@ -0,0 +1,71 @@
+* Renesas Clock Pulse Generator / Module Standby and Software Reset
+
+On Renesas ARM SoCs (SH/R-Mobile, R-Car, RZ), the CPG (Clock Pulse Generator)
+and MSSR (Module Standby and Software Reset) blocks are intimately connected,
+and share the same register block.
+
+They provide the following functionalities:
+  - The CPG block generates various core clocks,
+  - The MSSR block provides two functions:
+      1. Module Standby, providing a Clock Domain to control the clock supply
+	 to individual SoC devices,
+      2. Reset Control, to perform a software reset of individual SoC devices.
+
+Required Properties:
+  - compatible: Must be one of:
+      - "renesas,r8a7791-cpg-mssr" for the r8a7791 SoC
+      - "renesas,r8a7795-cpg-mssr" for the r8a7795 SoC
+
+  - reg: Base address and length of the memory resource used by the CPG/MSSR
+    block
+
+  - clocks: References to external parent clocks, one entry for each entry in
+    clock-names
+  - clock-names: List of external parent clock names. Valid names are:
+      - "extal" (r8a7791, r8a7795)
+      - "extalr" (r8a7795)
+      - "usb_extal" (r8a7791)
+
+  - #clock-cells: Must be 2
+      - For CPG core clocks, the two clock specifier cells must be "CPG_CORE"
+	and a core clock reference, as defined in
+	<dt-bindings/clock/*-cpg-mssr.h>.
+      - For module clocks, the two clock specifier cells must be "CPG_MOD" and
+	a module number, as defined in the datasheet.
+
+  - #power-domain-cells: Must be 0
+      - SoC devices that are part of the CPG/MSSR Clock Domain and can be
+	power-managed through Module Standby should refer to the CPG device
+	node in their "power-domains" property, as documented by the generic PM
+	Domain bindings in
+	Documentation/devicetree/bindings/power/power_domain.txt.
+
+
+Examples
+--------
+
+  - CPG device node:
+
+	cpg: clock-controller@e6150000 {
+		compatible = "renesas,r8a7795-cpg-mssr";
+		reg = <0 0xe6150000 0 0x1000>;
+		clocks = <&extal_clk>, <&extalr_clk>;
+		clock-names = "extal", "extalr";
+		#clock-cells = <2>;
+		#power-domain-cells = <0>;
+	};
+
+
+  - CPG/MSSR Clock Domain member device node:
+
+	scif2: serial@e6e88000 {
+		compatible = "renesas,scif-r8a7795", "renesas,scif";
+		reg = <0 0xe6e88000 0 64>;
+		interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&cpg CPG_MOD 310>;
+		clock-names = "sci_ick";
+		dmas = <&dmac1 0x13>, <&dmac1 0x12>;
+		dma-names = "tx", "rx";
+		power-domains = <&cpg>;
+		status = "disabled";
+	};
diff --git a/include/dt-bindings/clock/renesas-cpg-mssr.h b/include/dt-bindings/clock/renesas-cpg-mssr.h
new file mode 100644
index 0000000000000000..569a3cc33ffb5bc7
--- /dev/null
+++ b/include/dt-bindings/clock/renesas-cpg-mssr.h
@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) 2015 Renesas Electronics Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#ifndef __DT_BINDINGS_CLOCK_RENESAS_CPG_MSSR_H__
+#define __DT_BINDINGS_CLOCK_RENESAS_CPG_MSSR_H__
+
+#define CPG_CORE			0	/* Core Clock */
+#define CPG_MOD				1	/* Module Clock */
+
+#endif /* __DT_BINDINGS_CLOCK_RENESAS_CPG_MSSR_H__ */
-- 
1.9.1

[PATCH/POC v3 2/3] clk: shmobile: Add r8a7791 CPG Core Clock Definitions

[Geert Uytterhoeven]

Add the R-Car M2-W CPG Core Clocks that are currently needed by the DTS.
More will be added when needed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
This is a Proof-of-Concept. Final definitions and values may be
different.

 include/dt-bindings/clock/r8a7791-cpg-mssr.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 include/dt-bindings/clock/r8a7791-cpg-mssr.h

diff --git a/include/dt-bindings/clock/r8a7791-cpg-mssr.h b/include/dt-bindings/clock/r8a7791-cpg-mssr.h
new file mode 100644
index 0000000000000000..a68093bc77f846fa
--- /dev/null
+++ b/include/dt-bindings/clock/r8a7791-cpg-mssr.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2013 Ideas On Board SPRL
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __DT_BINDINGS_CLOCK_R8A7791_CPG_MSSR_H__
+#define __DT_BINDINGS_CLOCK_R8A7791_CPG_MSSR_H__
+
+#include <dt-bindings/clock/renesas-cpg-mssr.h>
+
+/* r8a7791 CPG Core Clocks */
+#define R8A7791_CLK_Z			0
+#define R8A7791_CLK_M2			1
+#define R8A7791_CLK_ADSP		2
+#define R8A7791_CLK_SD0			3
+#define R8A7791_CLK_RCAN		4
+
+#endif /* __DT_BINDINGS_CLOCK_R8A7791_CPG_MSSR_H__ */
-- 
1.9.1

[PATCH/POC v3 3/3] clk: shmobile: Add r8a7795 CPG Core Clock Definitions

[Geert Uytterhoeven]

Add the R-Car H3 CPG Core Clocks that are currently needed by the DTS.
More will be added when needed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
This is a Proof-of-Concept. Final definitions and values may be
different.

 include/dt-bindings/clock/r8a7795-cpg-mssr.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 include/dt-bindings/clock/r8a7795-cpg-mssr.h

diff --git a/include/dt-bindings/clock/r8a7795-cpg-mssr.h b/include/dt-bindings/clock/r8a7795-cpg-mssr.h
new file mode 100644
index 0000000000000000..c277eb2f48df22ec
--- /dev/null
+++ b/include/dt-bindings/clock/r8a7795-cpg-mssr.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (C) 2015 Renesas Electronics Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#ifndef __DT_BINDINGS_CLOCK_R8A7795_CPG_MSSR_H__
+#define __DT_BINDINGS_CLOCK_R8A7795_CPG_MSSR_H__
+
+#include <dt-bindings/clock/renesas-cpg-mssr.h>
+
+/* r8a7795 CPG Core Clocks */
+#define R8A7795_CLK_S0D4		0
+
+#endif /* __DT_BINDINGS_CLOCK_R8A7795_CPG_MSSR_H__ */
-- 
1.9.1