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clk: Add APM X-Gene SoC clock driver

PATCH Superseded Loc Ho 3 participants 13 messages Jun 21, 2013 – Jun 24, 2013

Subsystems (2)

v1 of 5 Superseded Latest is v5 →

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Loc Ho

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#0 lore raw

cover clk: Add APM X-Gene SoC clock driver

This patch adds APM X-Gene SoC clock driver support. Reference, PCP PLL, SoC PCP, and Ethernet clocks are defined via the DTS.

Loc Ho (3):
clk: Add APM X-Gene SoC clock driver with reference, PLL, and device
clocks.
clk: arm64: Add DTS clock entry for APM X-Gene Storm SoC.
Documentation: Add documentation for APM X-Gene clock binding.

 Documentation/devicetree/bindings/clock/xgene.txt |   90 ++++
 arch/arm64/boot/dts/apm-storm.dtsi                |   75 +++
 drivers/clk/Kconfig                               |    7 +
 drivers/clk/Makefile                              |    1 +
 drivers/clk/clk-xgene.c                           |  538 +++++++++++++++++++++
 5 files changed, 711 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/xgene.txt
 create mode 100644 drivers/clk/clk-xgene.c
author
#1 lore raw

PATCH 1/3 clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

---
 drivers/clk/Kconfig     |    7 +
 drivers/clk/Makefile    |    1 +
 drivers/clk/clk-xgene.c |  538 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 546 insertions(+), 0 deletions(-)
 create mode 100644 drivers/clk/clk-xgene.c
drivers/clk/Kconfig +7 -0
index 0357ac4..aa4d8b6 100644
@@ -81,6 +81,13 @@ config COMMON_CLK_AXI_CLKGEN
 	  Support for the Analog Devices axi-clkgen pcore clock generator for Xilinx
 	  FPGAs. It is commonly used in Analog Devices' reference designs.
 
+config COMMON_CLK_XGENE
+	bool "Clock driver for APM XGene SoC"
+	default y
+	depends on ARCH_XGENE
+	---help---
+	  Sypport for the APM X-Gene SoC reference, PLL, and device clocks.
+
 endmenu
 
 source "drivers/clk/mvebu/Kconfig"
drivers/clk/Makefile +1 -0
index 137d3e7..4c96337 100644
@@ -39,3 +39,4 @@ obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
 obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
 obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o
 obj-$(CONFIG_CLK_TWL6040)	+= clk-twl6040.o
+obj-$(CONFIG_COMMON_CLK_XGENE)  += clk-xgene.o
drivers/clk/clk-xgene.c new file +538 -0

538 lines not on this page · raw message

Signature · 1 line
1.5.5
author
#2 lore raw

PATCH 2/3 clk: arm64: Add DTS clock entry for APM X-Gene Storm SoC.

clk: arm64: Add DTS clock entry for APM X-Gene Storm SoC with reference to reference, PCP PLL, SoC PLL, and Ethernet clocks.

---
 arch/arm64/boot/dts/apm-storm.dtsi |   75 ++++++++++++++++++++++++++++++++++++
 1 files changed, 75 insertions(+), 0 deletions(-)
arch/arm64/boot/dts/apm-storm.dtsi +75 -0
index bfdc578..d994806 100644
@@ -103,6 +103,81 @@
 		#size-cells = <2>;
 		ranges;
 
+		clocks {
+			#address-cells = <2>;
+			#size-cells = <2>;
+			ranges;
+			refclk: refclk {
+				compatible = "fixed-clock";
+				#clock-cells = <1>;
+				clock-frequency = <100000000>;
+				clock-output-names = "refclk";
+			};
+
+			pcppll: pcppll at 17000100 {
+				compatible = "apm,xgene-pll-clock";
+				#clock-cells = <1>;
+				clocks = <&refclk 0>;
+				clock-names = "pcppll";
+				reg = <0x0 0x17000100 0x0 0x1000>;
+				clock-output-names = "pcppll";
+				type = <0>;
+			};
+
+			socpll: socpll at 17000120 {
+				compatible = "apm,xgene-pll-clock";
+				#clock-cells = <1>;
+				clocks = <&refclk 0>;
+				clock-names = "socpll";
+				reg = <0x0 0x17000120 0x0 0x1000>;
+				clock-output-names = "socpll";
+				type = <1>;
+			};
+
+			socplldiv2: socplldiv2  {
+				compatible = "fixed-factor-clock";
+				#clock-cells = <1>;
+				clocks = <&socpll 0>;
+				clock-names = "socplldiv2";
+				clock-mult = <1>;
+				clock-div = <2>;
+				clock-output-names = "socplldiv2";
+			};
+
+			qmlclk: qmlclk {
+				compatible = "apm,xgene-device-clock";
+				#clock-cells = <1>;
+				clocks = <&socplldiv2 0>;
+				clock-names = "qmlclk";
+				reg = <0x0 0x1703C000 0x0 0x1000
+					0x0 0x00000000 0x0 0x0000>;
+				clock-output-names = "qmlclk";
+			};
+
+			ethclk: ethclk {
+				compatible = "apm,xgene-device-clock";
+				#clock-cells = <1>;
+				clocks = <&socplldiv2 0>;
+				clock-names = "ethclk";
+				reg = <0x0 0x00000000 0x0 0x0000
+					0x0 0x17000000 0x0 0x1000>;
+				divider-offset = <0x238>;
+				divider-width = <0x9>;
+				divider-shift = <0x0>;
+				clock-output-names = "ethclk";
+			};
+
+			eth8clk: eth8clk {
+				compatible = "apm,xgene-device-clock";
+				#clock-cells = <1>;
+				clocks = <&ethclk 0>;
+				clock-names = "eth8clk";
+				reg = <0x0 0x1702C000 0x0 0x1000
+					0x0 0x00000000 0x0 0x0000>;
+				clock-output-names = "eth8clk";
+			};
+		};
+
 		serial0: serial at 1c020000 {
 			device_type = "serial";
 			compatible = "ns16550";
Signature · 1 line
1.5.5
author
#3 lore raw

PATCH 3/3 Documentation: Add documentation for APM X-Gene clock binding.

Documentation: Add documentation for APM X-Gene clock binding with PLL and device clocks.

---
 Documentation/devicetree/bindings/clock/xgene.txt |   90 +++++++++++++++++++++
 1 files changed, 90 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/xgene.txt
Documentation/devicetree/bindings/clock/xgene.txt new file +90 -0
new file mode 100644
index 0000000..fcdee79
@@ -0,0 +1,90 @@
+Device Tree Clock bindings for APM X-Gene
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be one of the following:
+	"apm,xgene-pll-clock" - for a X-Gene PLL clock
+	"apm,xgene-device-clock" - for a X-Gene device clock
+
+Required properties for PLL clocks:
+- reg : shall be the physical PLL register address for the pll clock.
+- clocks : shall be the input parent clock phandle for the clock. This should
+	be the reference clock.
+- #clock-cells : shall be set to 1.
+- clock-output-names : shall be the name of the PLL referenced by derive
+  clock.
+- type : shall be 1 for SoC PLL and 0 for PCP PLL.
+Optional properties for PLL clocks:
+- clock-names : shall be the name of the PLL. If missing, use the device name.
+
+Required properties for device clocks:
+- reg : shall be the physical CSR reset address base and physical CSR divider
+        address base. If one does not exist, specify 0 for address and 0 for 
+        size.
+- clocks : shall be the input parent clock phandle for the clock.
+- #clock-cells : shall be set to 1.
+- clock-output-names : shall be the name of the device referenced.
+Optional properties for device clocks:
+- clock-names : shall be the name of the device clock. If missing, use the
+                device name.
+- flags : Any clock flags. ie. use 0x8 to leave clock un-touch if not
+          referenced. Default is 0.
+- csr-offset : Offset to the CSR reset register from the reset address base.
+               Default is 0.
+- csr-mask : CSR reset mask bit. Default is 0xF.
+- enable-offset : Offset to the enable register from the reset address base.
+                  Default is 0x8.
+- enable-mask : CSR enable mask bit. Default is 0xF.
+- divider-offset : Offset to the divider CSR register from the divider base.
+                   Default is 0x0.
+- divider-width : Width of the divider register. Default is 0.
+- divider-shift : Bit shift of the divider register. Default is 0.
+
+For example:
+
+	pcppll: pcppll at 17000100 {
+		compatible = "apm,xgene-pll-clock";
+		#clock-cells = <1>;
+		clocks = <&refclk 0>;
+		clock-names = "pcppll";
+		reg = <0x0 0x17000100 0x0 0x1000>;
+		clock-output-names = "pcppll";
+		type = <0>;
+	};
+
+	socpll: socpll at 17000120 {
+		compatible = "apm,xgene-pll-clock";
+		#clock-cells = <1>;
+		clocks = <&refclk 0>;
+		clock-names = "socpll";
+		reg = <0x0 0x17000120 0x0 0x1000>;
+		clock-output-names = "socpll";
+		type = <1>;
+	};
+
+	qmlclk: qmlclk {
+		compatible = "apm,xgene-device-clock";
+		#clock-cells = <1>;
+		clocks = <&socplldiv2 0>;
+		clock-names = "qmlclk";
+		reg = <0x0 0x1703C000 0x0 0x1000
+			0x0 0x00000000 0x0 0x0000>;
+		clock-output-names = "qmlclk";
+	};
+
+	ethclk: ethclk {
+		compatible = "apm,xgene-device-clock";
+		#clock-cells = <1>;
+		clocks = <&socplldiv2 0>;
+		clock-names = "ethclk";
+		reg = <0x0 0x00000000 0x0 0x0000
+			0x0 0x17000000 0x0 0x1000>;
+			divider-offset = <0x238>;
+		divider-width = <0x9>;
+		divider-shift = <0x0>;
+		clock-output-names = "ethclk";
+	};
+
Signature · 1 line
1.5.5
#4 lore raw

PATCH 3/3 Documentation: Add documentation for APM X-Gene clock binding.

Quoted 27 lines · Loc Ho

Documentation: Add documentation for APM X-Gene clock binding with PLL and device clocks.

---
 Documentation/devicetree/bindings/clock/xgene.txt |   90 +++++++++++++++++++++
 1 files changed, 90 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/xgene.txt
Documentation/devicetree/bindings/clock/xgene.txt new file +9 -0
new file mode 100644
index 0000000..fcdee79
@@ -0,0 +1,90 @@
+Device Tree Clock bindings for APM X-Gene
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be one of the following:
+	"apm,xgene-pll-clock" - for a X-Gene PLL clock

Documentation/devicetree/bindings/clock/xgene.txt line 19

Quoted 10 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +10 -0
+	"apm,xgene-device-clock" - for a X-Gene device clock
+
+Required properties for PLL clocks:
+- reg : shall be the physical PLL register address for the pll clock.
+- clocks : shall be the input parent clock phandle for the clock. This should
+	be the reference clock.
+- #clock-cells : shall be set to 1.
+- clock-output-names : shall be the name of the PLL referenced by derive
+  clock.
+- type : shall be 1 for SoC PLL and 0 for PCP PLL.

That makes the binding very difficult for a human to read, could this not be part of the compatible string? e.g. "apm,xgene-pcp-pll-clock".

Quoted 5 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +5 -0
+Optional properties for PLL clocks:
+- clock-names : shall be the name of the PLL. If missing, use the device name.
+
+Required properties for device clocks:
+- reg : shall be the physical CSR reset address base and physical CSR divider

Documentation/devicetree/bindings/clock/xgene.txt line 34

Quoted 10 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +10 -0
+        address base. If one does not exist, specify 0 for address and 0 for 
+        size.
+- clocks : shall be the input parent clock phandle for the clock.
+- #clock-cells : shall be set to 1.
+- clock-output-names : shall be the name of the device referenced.
+Optional properties for device clocks:
+- clock-names : shall be the name of the device clock. If missing, use the
+                device name.
+- flags : Any clock flags. ie. use 0x8 to leave clock un-touch if not
+          referenced. Default is 0.

What flags are these? We should *not* be exporting Linux-internal flags as devicetree bindings.

Quoted 41 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +41 -0
+- csr-offset : Offset to the CSR reset register from the reset address base.
+               Default is 0.
+- csr-mask : CSR reset mask bit. Default is 0xF.
+- enable-offset : Offset to the enable register from the reset address base.
+                  Default is 0x8.
+- enable-mask : CSR enable mask bit. Default is 0xF.
+- divider-offset : Offset to the divider CSR register from the divider base.
+                   Default is 0x0.
+- divider-width : Width of the divider register. Default is 0.
+- divider-shift : Bit shift of the divider register. Default is 0.
+
+For example:
+
+	pcppll: pcppll at 17000100 {
+		compatible = "apm,xgene-pll-clock";
+		#clock-cells = <1>;
+		clocks = <&refclk 0>;
+		clock-names = "pcppll";
+		reg = <0x0 0x17000100 0x0 0x1000>;
+		clock-output-names = "pcppll";
+		type = <0>;
+	};
+
+	socpll: socpll at 17000120 {
+		compatible = "apm,xgene-pll-clock";
+		#clock-cells = <1>;
+		clocks = <&refclk 0>;
+		clock-names = "socpll";
+		reg = <0x0 0x17000120 0x0 0x1000>;
+		clock-output-names = "socpll";
+		type = <1>;
+	};
+
+	qmlclk: qmlclk {
+		compatible = "apm,xgene-device-clock";
+		#clock-cells = <1>;
+		clocks = <&socplldiv2 0>;
+		clock-names = "qmlclk";
+		reg = <0x0 0x1703C000 0x0 0x1000
+			0x0 0x00000000 0x0 0x0000>;
+		clock-output-names = "qmlclk";

Documentation/devicetree/bindings/clock/xgene.txt line 85

Quoted 10 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +10 -0
+	};
+
+	ethclk: ethclk {
+		compatible = "apm,xgene-device-clock";
+		#clock-cells = <1>;
+		clocks = <&socplldiv2 0>;
+		clock-names = "ethclk";
+		reg = <0x0 0x00000000 0x0 0x0000
+			0x0 0x17000000 0x0 0x1000>;
+			divider-offset = <0x238>;

Extraneous tab here.

Thanks,
Mark.

author
#5 lore raw

PATCH 3/3 Documentation: Add documentation for APM X-Gene clock binding.

HI,

Quoted 11 lines

Documentation/devicetree/bindings/clock/xgene.txt line 19

Quoted 8 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +8 -0
+Required properties for PLL clocks:
+- reg : shall be the physical PLL register address for the pll clock.
+- clocks : shall be the input parent clock phandle for the clock. This should
+     be the reference clock.
+- #clock-cells : shall be set to 1.
+- clock-output-names : shall be the name of the PLL referenced by derive
+  clock.
+- type : shall be 1 for SoC PLL and 0 for PCP PLL.

That makes the binding very difficult for a human to read, could this not be part of the compatible string? e.g. "apm,xgene-pcp-pll-clock".

[Loc Ho]
I guess I could by they will only differ by one function in term of rate computation.

Quoted 11 lines
Quoted 11 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +10 -0
+Optional properties for PLL clocks:
+- clock-names : shall be the name of the PLL. If missing, use the device name.
+
+Required properties for device clocks:
+- reg : shall be the physical CSR reset address base and physical CSR divider
+        address base. If one does not exist, specify 0 for address and 0 for
+        size.
+- clocks : shall be the input parent clock phandle for the clock.
+- #clock-cells : shall be set to 1.
+- clock-output-names : shall be the name of the device referenced.
Quoted 8 lines

Documentation/devicetree/bindings/clock/xgene.txt line 34

Quoted 5 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +5 -0
+Optional properties for device clocks:
+- clock-names : shall be the name of the device clock. If missing, use the
+                device name.
+- flags : Any clock flags. ie. use 0x8 to leave clock un-touch if not
+          referenced. Default is 0.

What flags are these? We should *not* be exporting Linux-internal flags as devicetree bindings.

[Loc Ho]
I need the CLK ignore if un-used. This is needed in case an subsystem
- such as PCIE is NOT powered on. With different board design, some IP may not have power. Accessing the clock registers will cause exception in the kernel. I guess I could just add the clock IGNORE by default and not require this.

-Loc

#6 lore raw

PATCH 3/3 Documentation: Add documentation for APM X-Gene clock binding.

Quoted 12 lines · Loc Ho

HI,

Quoted 9 lines
Quoted 8 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +8 -0
+Required properties for PLL clocks:
+- reg : shall be the physical PLL register address for the pll clock.
+- clocks : shall be the input parent clock phandle for the clock. This should
+     be the reference clock.
+- #clock-cells : shall be set to 1.
+- clock-output-names : shall be the name of the PLL referenced by derive
+  clock.
+- type : shall be 1 for SoC PLL and 0 for PCP PLL.
Quoted 5 lines
Quoted 2 lines

That makes the binding very difficult for a human to read, could this not be part of the compatible string? e.g. "apm,xgene-pcp-pll-clock".

[Loc Ho]
I guess I could by they will only differ by one function in term of rate computation.

Having a clear binding is useful, and it's just as easy to do a comparison on the compatible string as it is to deal with the an opaque type parameter. Another option would be to make the type parameter a string (i.e type = "soc" or type = "pcp"), if you feel that they are similar enough to not warrant separate bindings.

Quoted 20 lines
Quoted 12 lines
Quoted 12 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +10 -0
+Optional properties for PLL clocks:
+- clock-names : shall be the name of the PLL. If missing, use the device name.
+
+Required properties for device clocks:
+- reg : shall be the physical CSR reset address base and physical CSR divider
+        address base. If one does not exist, specify 0 for address and 0 for
+        size.
+- clocks : shall be the input parent clock phandle for the clock.
+- #clock-cells : shall be set to 1.
+- clock-output-names : shall be the name of the device referenced.
Quoted 8 lines

Documentation/devicetree/bindings/clock/xgene.txt line 34

Quoted 5 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +5 -0
+Optional properties for device clocks:
+- clock-names : shall be the name of the device clock. If missing, use the
+                device name.
+- flags : Any clock flags. ie. use 0x8 to leave clock un-touch if not
+          referenced. Default is 0.

What flags are these? We should *not* be exporting Linux-internal flags as devicetree bindings.

Quoted 6 lines

[Loc Ho]
I need the CLK ignore if un-used. This is needed in case an subsystem
- such as PCIE is NOT powered on. With different board design, some IP may not have power. Accessing the clock registers will cause exception in the kernel. I guess I could just add the clock IGNORE by default and not require this.

In cases where the clocks (or any devices) are unusable on a system for some reason (e.g. they are unpowered), you could instead set their status property to "disabled" in a board-specific dts to describe this (or deafualt them to "disabled" and override this to "okay" in a board file). That's the conventional way of doing it, and there's already framework for this in the kernel that prevents them from getting probed (though I'm not enitrely sure if this is the case when using *_OF_DECLARE).

Thanks,
Mark.

author
#7 lore raw

PATCH 3/3 Documentation: Add documentation for APM X-Gene clock binding.

Hi,

Quoted 15 lines
Quoted 9 lines
Quoted 9 lines
Quoted 8 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +8 -0
+Required properties for PLL clocks:
+- reg : shall be the physical PLL register address for the pll clock.
+- clocks : shall be the input parent clock phandle for the clock. This should
+     be the reference clock.
+- #clock-cells : shall be set to 1.
+- clock-output-names : shall be the name of the PLL referenced by derive
+  clock.
+- type : shall be 1 for SoC PLL and 0 for PCP PLL.
Quoted 5 lines
Quoted 2 lines

That makes the binding very difficult for a human to read, could this not be part of the compatible string? e.g. "apm,xgene-pcp-pll-clock".

[Loc Ho]
I guess I could by they will only differ by one function in term of rate computation.

Quoted 5 lines

Having a clear binding is useful, and it's just as easy to do a comparison on the compatible string as it is to deal with the an opaque type parameter. Another option would be to make the type parameter a string (i.e type = "soc" or type = "pcp"), if you feel that they are similar enough to not warrant separate bindings.

[Loc Ho]
I just create two binding type. And just set the type parameter based on binding.

Quoted 25 lines
Quoted 18 lines
Quoted 10 lines
Quoted 10 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +10 -0
+Optional properties for PLL clocks:
+- clock-names : shall be the name of the PLL. If missing, use the device name.
+
+Required properties for device clocks:
+- reg : shall be the physical CSR reset address base and physical CSR divider
+        address base. If one does not exist, specify 0 for address and 0 for
+        size.
+- clocks : shall be the input parent clock phandle for the clock.
+- #clock-cells : shall be set to 1.
+- clock-output-names : shall be the name of the device referenced.
Quoted 8 lines

Documentation/devicetree/bindings/clock/xgene.txt line 34

Quoted 5 lines
Documentation/devicetree/bindings/clock/xgene.txt new file +5 -0
+Optional properties for device clocks:
+- clock-names : shall be the name of the device clock. If missing, use the
+                device name.
+- flags : Any clock flags. ie. use 0x8 to leave clock un-touch if not
+          referenced. Default is 0.

What flags are these? We should *not* be exporting Linux-internal flags as devicetree bindings.

Quoted 6 lines

[Loc Ho]
I need the CLK ignore if un-used. This is needed in case an subsystem
- such as PCIE is NOT powered on. With different board design, some IP may not have power. Accessing the clock registers will cause exception in the kernel. I guess I could just add the clock IGNORE by default and not require this.

Quoted 8 lines

In cases where the clocks (or any devices) are unusable on a system for some reason (e.g. they are unpowered), you could instead set their status property to "disabled" in a board-specific dts to describe this (or deafualt them to "disabled" and override this to "okay" in a board file). That's the conventional way of doing it, and there's already framework for this in the kernel that prevents them from getting probed (though I'm not enitrely sure if this is the case when using *_OF_DECLARE).

[Loc Ho]
We are doing this. Though, this requires two set of DTS file and/or patching the DTS from U-Boot or BIOS. I am trying to avoid having multiple DTS file and having to write patching code.

-Loc

#8 lore raw

PATCH 1/3 clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

In reply to Loc Ho
Quoted 18 lines · Loc Ho

clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

---
 drivers/clk/Kconfig     |    7 +
 drivers/clk/Makefile    |    1 +
 drivers/clk/clk-xgene.c |  538 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 546 insertions(+), 0 deletions(-)
 create mode 100644 drivers/clk/clk-xgene.c
drivers/clk/Kconfig +0 -0
index 0357ac4..aa4d8b6 100644

drivers/clk/Kconfig config COMMON_CLK_AXI_CLKGEN · line 89

Quoted 9 lines
drivers/clk/Kconfig +6 -0
@@ -81,6 +81,13 @@ config COMMON_CLK_AXI_CLKGEN
          Support for the Analog Devices axi-clkgen pcore clock generator for Xilinx
          FPGAs. It is commonly used in Analog Devices' reference designs.
 
+config COMMON_CLK_XGENE
+       bool "Clock driver for APM XGene SoC"
+       default y
+       depends on ARCH_XGENE
+       ---help---
+         Sypport for the APM X-Gene SoC reference, PLL, and device clocks.

Like the recent vexpress changes, you can make this depend on ARM64 only.

Signature · 1 line
Catalin
#9 lore raw

PATCH 1/3 clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

In reply to Loc Ho

Hi,

I have some general comments, mostly on the devicetree side of things.

Quoted 173 lines · Loc Ho

clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

---
 drivers/clk/Kconfig     |    7 +
 drivers/clk/Makefile    |    1 +
 drivers/clk/clk-xgene.c |  538 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 546 insertions(+), 0 deletions(-)
 create mode 100644 drivers/clk/clk-xgene.c
drivers/clk/Kconfig +7 -0
index 0357ac4..aa4d8b6 100644
@@ -81,6 +81,13 @@ config COMMON_CLK_AXI_CLKGEN
          Support for the Analog Devices axi-clkgen pcore clock generator for Xilinx
          FPGAs. It is commonly used in Analog Devices' reference designs.
 
+config COMMON_CLK_XGENE
+       bool "Clock driver for APM XGene SoC"
+       default y
+       depends on ARCH_XGENE
+       ---help---
+         Sypport for the APM X-Gene SoC reference, PLL, and device clocks.
+
 endmenu
 
 source "drivers/clk/mvebu/Kconfig"
drivers/clk/Makefile +1 -0
index 137d3e7..4c96337 100644
@@ -39,3 +39,4 @@ obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
 obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
 obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o
 obj-$(CONFIG_CLK_TWL6040)      += clk-twl6040.o
+obj-$(CONFIG_COMMON_CLK_XGENE)  += clk-xgene.o
drivers/clk/clk-xgene.c new file +127 -0
new file mode 100644
index 0000000..8b81e89
@@ -0,0 +1,538 @@
+/*
+ * clk-xgene.c - AppliedMicro X-Gene Clock Interface
+ *
+ * Copyright (c) 2013, Applied Micro Circuits Corporation
+ * Author: Loc Ho <[email protected]>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/of_address.h>
+#include <asm/setup.h>
+
+/* Register SCU_PCPPLL bit fields */
+#define N_DIV_RD(src)                  (((src) & 0x000001ff))
+
+/* Register SCU_SOCPLL bit fields */
+#define CLKR_RD(src)                   (((src) & 0x07000000)>>24)
+#define CLKOD_RD(src)                  (((src) & 0x00300000)>>20)
+#define REGSPEC_RESET_F1_MASK          0x00010000
+#define CLKF_RD(src)                   (((src) & 0x000001ff))
+
+#define XGENE_CLK_DRIVER_VER           "0.1"
+
+static DEFINE_SPINLOCK(clk_lock);
+
+static inline u32 xgene_clk_read(void *csr)
+{
+       return readl_relaxed(csr);
+}
+
+static inline void xgene_clk_write(u32 data, void *csr)
+{
+       return writel_relaxed(data, csr);
+}
+
+/* PLL Clock */
+enum xgene_pll_type {
+       PLL_TYPE_PCP = 0,
+       PLL_TYPE_SOC = 1,
+};
+
+struct xgene_clk_pll {
+       struct clk_hw   hw;
+       const char      *name;
+       void __iomem    *reg;
+       spinlock_t      *lock;
+       u32             pll_offset;
+       enum xgene_pll_type     type;
+};
+
+#define to_xgene_clk_pll(_hw) container_of(_hw, struct xgene_clk_pll, hw)
+
+static int xgene_clk_pll_is_enabled(struct clk_hw *hw)
+{
+       struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
+       u32 data;
+
+       data = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
+       pr_debug("%s pll %s\n", pllclk->name,
+               data & REGSPEC_RESET_F1_MASK ? "disabled" : "enabled");
+
+       return data & REGSPEC_RESET_F1_MASK ? 0 : 1;
+}
+
+static unsigned long xgene_clk_pll_recalc_rate(struct clk_hw *hw,
+                               unsigned long parent_rate)
+{
+       struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
+       unsigned long fref;
+       unsigned long fvco;
+       u32 pll;
+       u32 nref;
+       u32 nout;
+       u32 nfb;
+
+       pll = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
+
+       if (pllclk->type == PLL_TYPE_PCP) {
+               /*
+                * PLL VCO = Reference clock * NF
+                * PCP PLL = PLL_VCO / 2
+                */
+               nout = 2;
+               fvco = parent_rate * (N_DIV_RD(pll) + 4);
+       } else {
+               /*
+                * Fref = Reference Clock / NREF;
+                * Fvco = Fref * NFB;
+                * Fout = Fvco / NOUT;
+                */
+               nref = CLKR_RD(pll) + 1;
+               nout = CLKOD_RD(pll) + 1;
+               nfb = CLKF_RD(pll);
+               fref = parent_rate / nref;
+               fvco = fref * nfb;
+       }
+       pr_debug("%s pll recalc rate %ld parent %ld\n", pllclk->name,
+               fvco / nout, parent_rate);
+
+       return fvco / nout;
+}
+
+const struct clk_ops xgene_clk_pll_ops = {
+       .is_enabled = xgene_clk_pll_is_enabled,
+       .recalc_rate = xgene_clk_pll_recalc_rate,
+};
+
+static struct clk *xgene_register_clk_pll(struct device *dev,

drivers/clk/clk-xgene.c line 137

Quoted 10 lines
drivers/clk/clk-xgene.c new file +10 -0
+       const char *name, const char *parent_name,
+       unsigned long flags, void __iomem *reg, u32 pll_offset,
+       u32 type, spinlock_t *lock)
+{
+       struct xgene_clk_pll *apmclk;
+       struct clk *clk;
+       struct clk_init_data init;
+
+       /* allocate the APM clock structure */
+       apmclk = kzalloc(sizeof(struct xgene_clk_pll), GFP_KERNEL);

You can do apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL) here, which is more robust with respect to type changes in future revisions of the driver.

Quoted 33 lines
drivers/clk/clk-xgene.c new file +33 -0
+       if (!apmclk) {
+               pr_err("%s: could not allocate APM clk\n", __func__);
+               return ERR_PTR(-ENOMEM);
+       }
+
+       init.name = name;
+       init.ops = &xgene_clk_pll_ops;
+       init.flags = flags;
+       init.parent_names = parent_name ? &parent_name : NULL;
+       init.num_parents = parent_name ? 1 : 0;
+
+       apmclk->name = name;
+       apmclk->reg = reg;
+       apmclk->lock = lock;
+       apmclk->pll_offset = pll_offset;
+       apmclk->type = type;
+       apmclk->hw.init = &init;
+
+       /* Register the clock */
+       clk = clk_register(dev, &apmclk->hw);
+       if (IS_ERR(clk)) {
+               pr_err("%s: could not register clk %s\n", __func__, name);
+               kfree(apmclk);
+               return NULL;
+       }
+       return clk;
+}
+
+static void xgene_pllclk_init(struct device_node *np)
+{
+       struct resource res;
+       const char *clk_name = np->full_name;
+       struct clk *clk;

drivers/clk/clk-xgene.c line 180

Quoted 10 lines
drivers/clk/clk-xgene.c new file +10 -0
+       void *reg;
+       int rc;
+       u32 type;
+
+       rc = of_address_to_resource(np, 0, &res);
+       if (rc != 0) {
+               pr_err("no DTS CSR register for %s\n", np->full_name);
+               return;
+       }
+       reg = ioremap(res.start, resource_size(&res));

You could just use reg = of_iomap(np, 0) here.

Quoted 220 lines
drivers/clk/clk-xgene.c new file +220 -0
+       if (reg == NULL) {
+               pr_err("Unable to map CSR register for %s\n", np->full_name);
+               return;
+       }
+       of_property_read_string(np, "clock-output-names", &clk_name);
+       if (of_property_read_u32(np, "type", &type))
+               type = 0;
+
+       clk = xgene_register_clk_pll(NULL,
+                       clk_name, of_clk_get_parent_name(np, 0),
+                       CLK_IS_ROOT, reg, 0, type, &clk_lock);
+       if (!IS_ERR(clk)) {
+               of_clk_add_provider(np, of_clk_src_simple_get, clk);
+               clk_register_clkdev(clk, clk_name, NULL);
+               pr_debug("Add %s clock PLL\n", clk_name);
+       }
+}
+
+/* IP Clock */
+struct xgene_dev_parameters {
+       u32  flags;                     /* Any flags to the clock framework */
+       void __iomem *csr_reg;          /* CSR for IP clock */
+       u32 reg_clk_offset;             /* Offset to clock enable CSR */
+       u32 reg_clk_mask;               /* Mask bit for clock enable */
+       u32 reg_csr_offset;             /* Offset to CSR reset */
+       u32 reg_csr_mask;               /* Mask bit for disable CSR reset */
+       void __iomem *divider_reg;      /* CSR for divider */
+       u32 reg_divider_offset;         /* Offset to divider register */
+       u32 reg_divider_shift;          /* Bit shift to divider field */
+       u32 reg_divider_width;          /* Width of the bit to divider field */
+};
+
+struct xgene_clk {
+       struct clk_hw   hw;
+       const char      *name;
+       spinlock_t      *lock;
+       struct xgene_dev_parameters     param;
+};
+
+#define to_xgene_clk(_hw) container_of(_hw, struct xgene_clk, hw)
+
+static int xgene_clk_enable(struct clk_hw *hw)
+{
+       struct xgene_clk *pclk = to_xgene_clk(hw);
+       unsigned long flags = 0;
+       u32 data;
+
+       if (pclk->lock)
+               spin_lock_irqsave(pclk->lock, flags);
+
+       if (pclk->param.csr_reg != NULL) {
+               pr_debug("%s clock enabled\n", pclk->name);
+               /* First enable the clock */
+               data = xgene_clk_read(pclk->param.csr_reg +
+                                       pclk->param.reg_clk_offset);
+               data |= pclk->param.reg_clk_mask;
+               xgene_clk_write(data, pclk->param.csr_reg +
+                                       pclk->param.reg_clk_offset);
+               pr_debug("%s clock PADDR base 0x%016LX clk offset 0x%08X mask 0x%08X value 0x%08X\n",
+                       pclk->name, __pa(pclk->param.csr_reg),
+                       pclk->param.reg_clk_offset, pclk->param.reg_clk_mask,
+                       data);
+
+               /* Second enable the CSR */
+               data = xgene_clk_read(pclk->param.csr_reg +
+                                       pclk->param.reg_csr_offset);
+               data &= ~pclk->param.reg_csr_mask;
+               xgene_clk_write(data, pclk->param.csr_reg +
+                                       pclk->param.reg_csr_offset);
+               pr_debug("%s CSR RESET PADDR base 0x%016LX csr offset 0x%08X mask 0x%08X value 0x%08X\n",
+                       pclk->name, __pa(pclk->param.csr_reg),
+                       pclk->param.reg_csr_offset, pclk->param.reg_csr_mask,
+                       data);
+       }
+
+       if (pclk->lock)
+               spin_unlock_irqrestore(pclk->lock, flags);
+
+       return 0;
+}
+
+static void xgene_clk_disable(struct clk_hw *hw)
+{
+       struct xgene_clk *pclk = to_xgene_clk(hw);
+       unsigned long flags = 0;
+       u32 data;
+
+       if (pclk->lock)
+               spin_lock_irqsave(pclk->lock, flags);
+
+       if (pclk->param.csr_reg != NULL) {
+               pr_debug("%s clock disabled\n", pclk->name);
+               /* First put the CSR in reset */
+               data = xgene_clk_read(pclk->param.csr_reg +
+                                       pclk->param.reg_csr_offset);
+               data |= pclk->param.reg_csr_mask;
+               xgene_clk_write(data, pclk->param.csr_reg +
+                                       pclk->param.reg_csr_offset);
+
+               /* Second disable the clock */
+               data = xgene_clk_read(pclk->param.csr_reg +
+                                       pclk->param.reg_clk_offset);
+               data &= ~pclk->param.reg_clk_mask;
+               xgene_clk_write(data, pclk->param.csr_reg +
+                                       pclk->param.reg_clk_offset);
+       }
+
+       if (pclk->lock)
+               spin_unlock_irqrestore(pclk->lock, flags);
+}
+
+static int xgene_clk_is_enabled(struct clk_hw *hw)
+{
+       struct xgene_clk *pclk = to_xgene_clk(hw);
+       u32 data = 0;
+
+       if (pclk->param.csr_reg != NULL) {
+               pr_debug("%s clock checking\n", pclk->name);
+               data = xgene_clk_read(pclk->param.csr_reg +
+                                       pclk->param.reg_clk_offset);
+               pr_debug("%s clock is %s\n", pclk->name,
+                       data & pclk->param.reg_clk_mask ? "enabled" :
+                                                       "disabled");
+       }
+
+       if (pclk->param.csr_reg == NULL)
+               return 1;
+       return data & pclk->param.reg_clk_mask ? 1 : 0;
+}
+
+static unsigned long xgene_clk_recalc_rate(struct clk_hw *hw,
+                               unsigned long parent_rate)
+{
+       struct xgene_clk *pclk = to_xgene_clk(hw);
+       u32 data;
+
+       if (pclk->param.divider_reg) {
+               data = xgene_clk_read(pclk->param.divider_reg +
+                                       pclk->param.reg_divider_offset);
+               data >>= pclk->param.reg_divider_shift;
+               data &= (1 << pclk->param.reg_divider_width) - 1;
+
+               pr_debug("%s clock recalc rate %ld parent %ld\n",
+                       pclk->name, parent_rate / data, parent_rate);
+               return parent_rate / data;
+       } else {
+               pr_debug("%s clock recalc rate %ld parent %ld\n",
+                       pclk->name, parent_rate, parent_rate);
+               return parent_rate;
+       }
+}
+
+static int xgene_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+                               unsigned long parent_rate)
+{
+       struct xgene_clk *pclk = to_xgene_clk(hw);
+       unsigned long flags = 0;
+       u32 data;
+       u32 divider;
+       u32 divider_save;
+
+       if (pclk->lock)
+               spin_lock_irqsave(pclk->lock, flags);
+
+       if (pclk->param.divider_reg) {
+               /* Let's compute the divider */
+               if (rate > parent_rate)
+                       rate = parent_rate;
+               divider_save = divider = parent_rate / rate; /* Rounded down */
+               divider &= (1 << pclk->param.reg_divider_width) - 1;
+               divider <<= pclk->param.reg_divider_shift;
+
+               /* Set new divider */
+               data = xgene_clk_read(pclk->param.divider_reg +
+                               pclk->param.reg_divider_offset);
+               data &= ~((1 << pclk->param.reg_divider_width) - 1);
+               data |= divider;
+               xgene_clk_write(data, pclk->param.divider_reg +
+                                       pclk->param.reg_divider_offset);
+               pr_debug("%s clock set rate %ld\n", pclk->name,
+                       parent_rate / divider_save);
+       } else {
+               divider_save = 1;
+       }
+
+       if (pclk->lock)
+               spin_unlock_irqrestore(pclk->lock, flags);
+
+       return parent_rate / divider_save;
+}
+
+static long xgene_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+                               unsigned long *prate)
+{
+       struct xgene_clk *pclk = to_xgene_clk(hw);
+       unsigned long parent_rate = *prate;
+       u32 divider;
+
+       if (pclk->param.divider_reg) {
+               /* Let's compute the divider */
+               if (rate > parent_rate)
+                       rate = parent_rate;
+               divider = parent_rate / rate;   /* Rounded down */
+       } else {
+               divider = 1;
+       }
+
+       return parent_rate / divider;
+}
+
+const struct clk_ops xgene_clk_ops = {
+       .enable = xgene_clk_enable,
+       .disable = xgene_clk_disable,
+       .is_enabled = xgene_clk_is_enabled,
+       .recalc_rate = xgene_clk_recalc_rate,
+       .set_rate = xgene_clk_set_rate,
+       .round_rate = xgene_clk_round_rate,
+};
+
+static struct clk *xgene_register_clk(struct device *dev,

drivers/clk/clk-xgene.c line 410

Quoted 10 lines
drivers/clk/clk-xgene.c new file +10 -0
+               const char *name, const char *parent_name,
+               struct xgene_dev_parameters *parameters, spinlock_t *lock)
+{
+       struct xgene_clk *apmclk;
+       struct clk *clk;
+       struct clk_init_data init;
+       int rc;
+
+       /* allocate the APM clock structure */
+       apmclk = kzalloc(sizeof(struct xgene_clk), GFP_KERNEL);

Again, you could use kzalloc(sizeof(*apmclk), GFP_KERNEL).

Quoted 12 lines
drivers/clk/clk-xgene.c new file +12 -0
+       if (!apmclk) {
+               pr_err("%s: could not allocate APM clk\n", __func__);
+               return ERR_PTR(-ENOMEM);
+       }
+
+       init.name = name;
+       init.ops = &xgene_clk_ops;
+       init.flags = parameters->flags;
+       init.parent_names = parent_name ? &parent_name : NULL;
+       init.num_parents = parent_name ? 1 : 0;
+
+       apmclk->name = name;

drivers/clk/clk-xgene.c line 432

Quoted 10 lines
drivers/clk/clk-xgene.c new file +10 -0
+       apmclk->lock = lock;
+       apmclk->hw.init = &init;
+       apmclk->param = *parameters;
+
+       /* Register the clock */
+       clk = clk_register(dev, &apmclk->hw);
+       if (IS_ERR(clk)) {
+               pr_err("%s: could not register clk %s\n", __func__, name);
+               kfree(apmclk);
+               return NULL;

As I understand it, NULL is a valid clock. Should you not return clk (which is an error value) here?

Quoted 21 lines
drivers/clk/clk-xgene.c new file +21 -0
+       }
+
+       /* Register the clock for lookup */
+       rc = clk_register_clkdev(clk, name, NULL);
+       if (rc != 0) {
+               pr_err("%s: could not register lookup clk %s\n",
+                       __func__, name);
+       }
+       return clk;
+}
+
+static void __init xgene_devclk_init(struct device_node *np)
+{
+       const char *clk_name = np->full_name;
+       struct clk *clk;
+       struct resource res;
+       int rc;
+       struct xgene_dev_parameters parameters;
+
+       rc = of_address_to_resource(np, 0, &res);
+       if (rc != 0) {

drivers/clk/clk-xgene.c line 463

Quoted 10 lines
drivers/clk/clk-xgene.c new file +10 -0
+               pr_err("no DTS CSR register for %s\n", np->full_name);
+               return;
+       }
+       if (resource_size(&res)) {
+               parameters.csr_reg = ioremap(res.start, resource_size(&res));
+               if (parameters.csr_reg == NULL) {
+                       pr_err("Unable to map CSR register for %s\n",
+                               np->full_name);
+                       return;
+               }

Use of_iomap(np, 0) here.

drivers/clk/clk-xgene.c line 466

Quoted 3 lines
drivers/clk/clk-xgene.c new file +3 -0
+       } else {
+               parameters.csr_reg = NULL;
+       }

Are you able to continue if this is the case?

Quoted 6 lines
drivers/clk/clk-xgene.c new file +6 -0
+
+       rc = of_address_to_resource(np, 1, &res);
+       if (rc != 0) {
+               pr_err("no DTS DIV register for %s\n", np->full_name);
+               return;
+       }

drivers/clk/clk-xgene.c line 482

Quoted 10 lines
drivers/clk/clk-xgene.c new file +10 -0
+       if (resource_size(&res)) {
+               parameters.divider_reg = ioremap(res.start,
+                                               resource_size(&res));
+               if (parameters.divider_reg == NULL) {
+                       pr_err("Unable to map DIV register for %s\n",
+                               np->full_name);
+                       if (parameters.csr_reg)
+                               iounmap(parameters.csr_reg);
+                       return;
+               }

Use of_iomap(np, 1) here.

drivers/clk/clk-xgene.c line 485

Quoted 3 lines
drivers/clk/clk-xgene.c new file +3 -0
+       } else {
+               parameters.divider_reg = NULL;
+       }

Similarly, are you able to continue with this being the case?

Quoted 33 lines
drivers/clk/clk-xgene.c new file +33 -0
+       if (of_property_read_u32(np, "flags", &parameters.flags))
+               parameters.flags = 0;
+       if (of_property_read_u32(np, "csr-offset", &parameters.reg_csr_offset))
+               parameters.reg_csr_offset = 0;
+       if (of_property_read_u32(np, "csr-mask", &parameters.reg_csr_mask))
+               parameters.reg_csr_mask = 0xF;
+       if (of_property_read_u32(np, "enable-offset",
+                               &parameters.reg_clk_offset))
+               parameters.reg_clk_offset = 0x8;
+       if (of_property_read_u32(np, "enable-mask", &parameters.reg_clk_mask))
+               parameters.reg_clk_mask = 0xF;
+       if (of_property_read_u32(np, "divider-offset",
+                               &parameters.reg_divider_offset))
+               parameters.reg_divider_offset = 0;
+       if (of_property_read_u32(np, "divider-width",
+                               &parameters.reg_divider_width))
+               parameters.reg_divider_width = 0;
+       if (of_property_read_u32(np, "divider-shift",
+                               &parameters.reg_divider_shift))
+               parameters.reg_divider_shift = 0;
+       of_property_read_string(np, "clock-output-names", &clk_name);
+
+       clk = xgene_register_clk(NULL, clk_name,
+               of_clk_get_parent_name(np, 0), &parameters, &clk_lock);
+       if (IS_ERR(clk)) {
+               if (parameters.csr_reg)
+                       iounmap(parameters.csr_reg);
+               if (parameters.divider_reg)
+                       iounmap(parameters.divider_reg);
+               return;
+       }
+       pr_debug("Add %s clock\n", clk_name);
+       rc = of_clk_add_provider(np, of_clk_src_simple_get, clk);

drivers/clk/clk-xgene.c line 528

Quoted 10 lines
drivers/clk/clk-xgene.c new file +10 -0
+       if (rc != 0) {
+               pr_err("%s: could register provider clk %s\n", __func__,
+                       np->full_name);
+               return;
+       }
+}
+
+CLK_OF_DECLARE(fixed_clock, "fixed-clock", of_fixed_clk_setup);
+CLK_OF_DECLARE(fixed_factor_clock, "fixed-factor-clock",
+               of_fixed_factor_clk_setup);

Why are these declared in your driver? Both fixed-clock and fixed-factor-clock are standard clock bindings with existing drivers which already have CLK_OF_DECLARE. Having a duplicate CLK_OF_DECLARE for those compatible strings is only going to cause problems.

See drivers/clk/clk-fixed-rate.c and drivers/clk/clk-fixed-factor.c.

drivers/clk/clk-xgene.c line 535

Quoted 7 lines
drivers/clk/clk-xgene.c new file +7 -0
+CLK_OF_DECLARE(xgene_pll_clock, "apm,xgene-pll-clock", xgene_pllclk_init);
+CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);
+
+static int __init xgene_clk_init(void)
+{
+       pr_info("XGene clock driver v%s\n", XGENE_CLK_DRIVER_VER);
+       of_clk_init(NULL);

As of_clk_init is called in arm64_device_init, why do you call it here? It looks very odd and I suspect you don't need it.

drivers/clk/clk-xgene.c line 538

Quoted 3 lines
drivers/clk/clk-xgene.c new file +3 -0
+       return 0;
+}
+arch_initcall(xgene_clk_init);

I think this initcall can go.

Thanks,
Mark

author
#10 lore raw

PATCH 1/3 clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

Hi,

I will fix them. With regard to continue where the CSR is NULL, it is possible to continue as long as both is NOT NULL.

Quoted 25 lines

Use of_iomap(np, 0) here.

drivers/clk/clk-xgene.c line 466

Quoted 3 lines
drivers/clk/clk-xgene.c new file +3 -0
+       } else {
+               parameters.csr_reg = NULL;
+       }

Are you able to continue if this is the case?

Quoted 6 lines
drivers/clk/clk-xgene.c new file +6 -0
+
+       rc = of_address_to_resource(np, 1, &res);
+       if (rc != 0) {
+               pr_err("no DTS DIV register for %s\n", np->full_name);
+               return;
+       }

drivers/clk/clk-xgene.c line 482

Quoted 10 lines
drivers/clk/clk-xgene.c new file +10 -0
+       if (resource_size(&res)) {
+               parameters.divider_reg = ioremap(res.start,
+                                               resource_size(&res));
+               if (parameters.divider_reg == NULL) {
+                       pr_err("Unable to map DIV register for %s\n",
+                               np->full_name);
+                       if (parameters.csr_reg)
+                               iounmap(parameters.csr_reg);
+                       return;
+               }
Quoted 7 lines

Use of_iomap(np, 1) here.

drivers/clk/clk-xgene.c line 485

Quoted 3 lines
drivers/clk/clk-xgene.c new file +3 -0
+       } else {
+               parameters.divider_reg = NULL;
+       }

Similarly, are you able to continue with this being the case?

-Loc

#11 lore raw

PATCH 1/3 clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

Quoted 4 lines · Loc Ho

Hi,

I will fix them. With regard to continue where the CSR is NULL, it is possible to continue as long as both is NOT NULL.

Ah, so one bank of registers might not be present? Given that, it might be worth using interrupt-names to describe which is present, so that you don't need to describe a non-existent register bank.

Thanks,
Mark.

Quoted 36 lines
Quoted 26 lines

Use of_iomap(np, 0) here.

drivers/clk/clk-xgene.c line 466

Quoted 3 lines
drivers/clk/clk-xgene.c new file +3 -0
+       } else {
+               parameters.csr_reg = NULL;
+       }

Are you able to continue if this is the case?

Quoted 6 lines
drivers/clk/clk-xgene.c new file +6 -0
+
+       rc = of_address_to_resource(np, 1, &res);
+       if (rc != 0) {
+               pr_err("no DTS DIV register for %s\n", np->full_name);
+               return;
+       }

drivers/clk/clk-xgene.c line 482

Quoted 10 lines
drivers/clk/clk-xgene.c new file +10 -0
+       if (resource_size(&res)) {
+               parameters.divider_reg = ioremap(res.start,
+                                               resource_size(&res));
+               if (parameters.divider_reg == NULL) {
+                       pr_err("Unable to map DIV register for %s\n",
+                               np->full_name);
+                       if (parameters.csr_reg)
+                               iounmap(parameters.csr_reg);
+                       return;
+               }
Quoted 7 lines

Use of_iomap(np, 1) here.

drivers/clk/clk-xgene.c line 485

Quoted 3 lines
drivers/clk/clk-xgene.c new file +3 -0
+       } else {
+               parameters.divider_reg = NULL;
+       }

Similarly, are you able to continue with this being the case?

-Loc

#12 lore raw

cover clk: Add APM X-Gene SoC clock driver

In reply to Loc Ho
Quoted 9 lines · Loc Ho

This patch adds APM X-Gene SoC clock driver support. Reference, PCP PLL, SoC PCP, and Ethernet clocks are defined via the DTS.

Loc Ho (3):
clk: Add APM X-Gene SoC clock driver with reference, PLL, and device
clocks.
clk: arm64: Add DTS clock entry for APM X-Gene Storm SoC.
Documentation: Add documentation for APM X-Gene clock binding.

Quoted 8 lines
 Documentation/devicetree/bindings/clock/xgene.txt |   90 ++++
 arch/arm64/boot/dts/apm-storm.dtsi                |   75 +++
 drivers/clk/Kconfig                               |    7 +
 drivers/clk/Makefile                              |    1 +
 drivers/clk/clk-xgene.c                           |  538 +++++++++++++++++++++
 5 files changed, 711 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/xgene.txt
 create mode 100644 drivers/clk/clk-xgene.c

You'll have to send these patches to Mike Turquette (cc'ed), they are not being merged via the arm64 tree.

Thanks.

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