diff mbox series

[v5,4/8] dt-bindings: PCI: kirin: Drop PHY properties

Message ID a04c9c92187ceaee0fd4b8d4721e2a3275d97518.1626157454.git.mchehab+huawei@kernel.org (mailing list archive)
State Superseded
Delegated to: Lorenzo Pieralisi
Headers show
Series Add support for Hikey 970 PCIe | expand

Commit Message

Mauro Carvalho Chehab July 13, 2021, 6:28 a.m. UTC
There are several properties there that belong to the PHY
interface. Drop them, as a new binding file will describe
the PHY properties for Kirin 960.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 .../devicetree/bindings/pci/kirin-pcie.txt       | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

Comments

Rob Herring July 14, 2021, 2:28 a.m. UTC | #1
On Tue, Jul 13, 2021 at 08:28:37AM +0200, Mauro Carvalho Chehab wrote:
> There are several properties there that belong to the PHY
> interface. Drop them, as a new binding file will describe
> the PHY properties for Kirin 960.

Folks are okay with an incompatible change on hikey960?

> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> ---
>  .../devicetree/bindings/pci/kirin-pcie.txt       | 16 +++-------------
>  1 file changed, 3 insertions(+), 13 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/pci/kirin-pcie.txt b/Documentation/devicetree/bindings/pci/kirin-pcie.txt
> index 71cac2b74002..a93a8cfa1afb 100644
> --- a/Documentation/devicetree/bindings/pci/kirin-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/kirin-pcie.txt
> @@ -10,13 +10,11 @@ Additional properties are described here:
>  Required properties
>  - compatible:
>  	"hisilicon,kirin960-pcie"
> -- reg: Should contain rc_dbi, apb, phy, config registers location and length.
> +- reg: Should contain rc_dbi, apb, config registers location and length.
>  - reg-names: Must include the following entries:
>    "dbi": controller configuration registers;
>    "apb": apb Ctrl register defined by Kirin;
> -  "phy": apb PHY register defined by Kirin;
>    "config": PCIe configuration space registers.
> -- reset-gpios: The GPIO to generate PCIe PERST# assert and deassert signal.
>  
>  Optional properties:
>  
> @@ -25,8 +23,8 @@ Example based on kirin960:
>  	pcie@f4000000 {
>  		compatible = "hisilicon,kirin960-pcie";
>  		reg = <0x0 0xf4000000 0x0 0x1000>, <0x0 0xff3fe000 0x0 0x1000>,
> -		      <0x0 0xf3f20000 0x0 0x40000>, <0x0 0xF4000000 0 0x2000>;
> -		reg-names = "dbi","apb","phy", "config";
> +		      <0x0 0xF4000000 0 0x2000>;
> +		reg-names = "dbi","apb", "config";
>  		bus-range = <0x0  0x1>;
>  		#address-cells = <3>;
>  		#size-cells = <2>;
> @@ -39,12 +37,4 @@ Example based on kirin960:
>  				<0x0 0 0 2 &gic 0 0 0  283 4>,
>  				<0x0 0 0 3 &gic 0 0 0  284 4>,
>  				<0x0 0 0 4 &gic 0 0 0  285 4>;
> -		clocks = <&crg_ctrl HI3660_PCIEPHY_REF>,
> -			 <&crg_ctrl HI3660_CLK_GATE_PCIEAUX>,
> -			 <&crg_ctrl HI3660_PCLK_GATE_PCIE_PHY>,
> -			 <&crg_ctrl HI3660_PCLK_GATE_PCIE_SYS>,
> -			 <&crg_ctrl HI3660_ACLK_GATE_PCIE>;
> -		clock-names = "pcie_phy_ref", "pcie_aux",
> -			      "pcie_apb_phy", "pcie_apb_sys", "pcie_aclk";
> -		reset-gpios = <&gpio11 1 0 >;
>  	};
> -- 
> 2.31.1
> 
>
Mauro Carvalho Chehab July 14, 2021, 11:22 a.m. UTC | #2
Em Tue, 13 Jul 2021 20:28:49 -0600
Rob Herring <robh@kernel.org> escreveu:

> On Tue, Jul 13, 2021 at 08:28:37AM +0200, Mauro Carvalho Chehab wrote:
> > There are several properties there that belong to the PHY
> > interface. Drop them, as a new binding file will describe
> > the PHY properties for Kirin 960.  
> 
> Folks are okay with an incompatible change on hikey960?

I hope so ;-)

I mean, it should be easy to add a backward-compatible code that
would make the PHY driver to use the pci-bus old schema if there's
no PHY entry at DT.

However, this is not enough, as the PHY driver won't be loaded/probed
without at least this at hi3660.dtsi:

	pcie_phy: pcie-phy@f3f2000 {
		compatible = "hisilicon,hi960-pcie-phy";
	};


So, some (probably ugly) hack would be needed at pcie-kirin, in order
to make it to manually load and probe the PHY driver, if it
founds (for instance) "phy" reg-name as a pcie-kirin property.

Thanks,
Mauro
Mauro Carvalho Chehab July 16, 2021, 11:22 a.m. UTC | #3
Em Tue, 13 Jul 2021 20:28:49 -0600
Rob Herring <robh@kernel.org> escreveu:

> On Tue, Jul 13, 2021 at 08:28:37AM +0200, Mauro Carvalho Chehab wrote:
> > There are several properties there that belong to the PHY
> > interface. Drop them, as a new binding file will describe
> > the PHY properties for Kirin 960.  
> 
> Folks are okay with an incompatible change on hikey960?

Accepting an incompatible change here seems the right thing to do.

Another possibility would be to create a "pcie-kirin-with-phy" driver
that would be identical to the existing one, except for the absence
of a PHY and using a different compatible string.

-

Long answer:

There aren't many alternatives here, if we want to split the PHY out of
the driver, as you requested.

I've been scratching my head in order to find a way that would keep
the Hikey960 a separate PHY driver, with a proper DT schema, but
capable of also parse the original DT schema.

See, making the phy driver parse the PCIE-based OF-node data is 
trivial (I have already a patch doing that), but it will require at
least some DT schema additions, in order to add a pcie_phy node[1]:

<snip>
diff --git a/arch/arm64/boot/dts/hisilicon/hi3660.dtsi b/arch/arm64/boot/dts/hisilicon/hi3660.dtsi
index e0eca598af1f..6aaa2f966d74 100644
--- a/arch/arm64/boot/dts/hisilicon/hi3660.dtsi
+++ b/arch/arm64/boot/dts/hisilicon/hi3660.dtsi
@@ -1001,6 +1001,11 @@ spi3: spi@ff3b3000 {
                        status = "disabled";
                };
 
+               pcie_phy: pcie-phy@f3f2000 {
+                       compatible = "hisilicon,hi960-pcie-phy";
+                       #phy-cells = <0>;
+               };
+
                pcie@f4000000 {
                        compatible = "hisilicon,kirin960-pcie";
                        reg = <0x0 0xf4000000 0x0 0x1000>,
@@ -1012,6 +1017,7 @@ pcie@f4000000 {
                        #address-cells = <3>;
                        #size-cells = <2>;
                        device_type = "pci";
+                       phys = <&pcie_phy>;
                        ranges = <0x02000000 0x0 0x00000000
                                  0x0 0xf6000000
                                  0x0 0x02000000>;
</snip>

[1] or, alternatively, the pcie-kirin driver would need to dynamically
    populate DT with the above, as some ACPI drivers do when the
    firmware is broken.

Without a PHY representation at the DT schema, the PHY driver won't 
be recognized by pcie-kirin.

See, even if the pcie-kirin driver would be changed to register
the PHY without DT, with:

	phy = devm_of_phy_get(dev, NULL, "hi3660_pcie_phy");

The phy_get() implementation will internally ignore a non-DT PHY,
as internally, it uses of_property_match_string() if the caller driver
has of_node:

	struct phy *phy_get(struct device *dev, const char *string)
	{
		int index = 0;
		struct phy *phy;
		struct device_link *link;

		if (dev->of_node) {
			if (string)
				index = of_property_match_string(dev->of_node, "phy-names",
					string);
			else
				index = 0;
			phy = _of_phy_get(dev->of_node, index);
		} else {
			if (string == NULL) {
				dev_WARN(dev, "missing string\n");
				return ERR_PTR(-EINVAL);
			}
			phy = phy_find(dev, string);
		}

Thanks,
Mauro
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/pci/kirin-pcie.txt b/Documentation/devicetree/bindings/pci/kirin-pcie.txt
index 71cac2b74002..a93a8cfa1afb 100644
--- a/Documentation/devicetree/bindings/pci/kirin-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/kirin-pcie.txt
@@ -10,13 +10,11 @@  Additional properties are described here:
 Required properties
 - compatible:
 	"hisilicon,kirin960-pcie"
-- reg: Should contain rc_dbi, apb, phy, config registers location and length.
+- reg: Should contain rc_dbi, apb, config registers location and length.
 - reg-names: Must include the following entries:
   "dbi": controller configuration registers;
   "apb": apb Ctrl register defined by Kirin;
-  "phy": apb PHY register defined by Kirin;
   "config": PCIe configuration space registers.
-- reset-gpios: The GPIO to generate PCIe PERST# assert and deassert signal.
 
 Optional properties:
 
@@ -25,8 +23,8 @@  Example based on kirin960:
 	pcie@f4000000 {
 		compatible = "hisilicon,kirin960-pcie";
 		reg = <0x0 0xf4000000 0x0 0x1000>, <0x0 0xff3fe000 0x0 0x1000>,
-		      <0x0 0xf3f20000 0x0 0x40000>, <0x0 0xF4000000 0 0x2000>;
-		reg-names = "dbi","apb","phy", "config";
+		      <0x0 0xF4000000 0 0x2000>;
+		reg-names = "dbi","apb", "config";
 		bus-range = <0x0  0x1>;
 		#address-cells = <3>;
 		#size-cells = <2>;
@@ -39,12 +37,4 @@  Example based on kirin960:
 				<0x0 0 0 2 &gic 0 0 0  283 4>,
 				<0x0 0 0 3 &gic 0 0 0  284 4>,
 				<0x0 0 0 4 &gic 0 0 0  285 4>;
-		clocks = <&crg_ctrl HI3660_PCIEPHY_REF>,
-			 <&crg_ctrl HI3660_CLK_GATE_PCIEAUX>,
-			 <&crg_ctrl HI3660_PCLK_GATE_PCIE_PHY>,
-			 <&crg_ctrl HI3660_PCLK_GATE_PCIE_SYS>,
-			 <&crg_ctrl HI3660_ACLK_GATE_PCIE>;
-		clock-names = "pcie_phy_ref", "pcie_aux",
-			      "pcie_apb_phy", "pcie_apb_sys", "pcie_aclk";
-		reset-gpios = <&gpio11 1 0 >;
 	};