[PATCH v2 0/2] add the Amlogic Meson PCIe controller driver.

[PATCH v2 0/2] add the Amlogic Meson PCIe controller driver.

[Hanjie Lin]

The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
PCI core. This patchset add the driver and dt-bindings of the controller.

Changes since v1: [0]
 - use gpio lib instead open code
 - move 'apb' and 'port' reset from phy driver
 - format correcting

[0] : https://lkml.org/lkml/2018/8/14/70

Yue Wang (2):
  dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe
    controller
  PCI: meson: add the Amlogic Meson PCIe controller driver

 .../devicetree/bindings/pci/amlogic,meson-pcie.txt |  63 +++
 drivers/pci/controller/dwc/Kconfig                 |  12 +
 drivers/pci/controller/dwc/Makefile                |   1 +
 drivers/pci/controller/dwc/pci-meson.c             | 613 +++++++++++++++++++++
 4 files changed, 689 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
 create mode 100644 drivers/pci/controller/dwc/pci-meson.c

-- 
2.7.4

[PATCH v2 1/2] dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller

[Hanjie Lin]

From: Yue Wang <yue.wang@amlogic.com>

The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
PCI core. This patch adds documentation for the DT bindings in Meson PCIe
controller.

Signed-off-by: Yue Wang <yue.wang@amlogic.com>
Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
---
 .../devicetree/bindings/pci/amlogic,meson-pcie.txt | 63 ++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt

diff --git a/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
new file mode 100644
index 0000000..8a831d1
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
@@ -0,0 +1,63 @@
+Amlogic Meson AXG DWC PCIE SoC controller
+
+Amlogic Meson PCIe host controller is based on the Synopsys DesignWare PCI core.
+It shares common functions with the PCIe DesignWare core driver and
+inherits common properties defined in
+Documentation/devicetree/bindings/pci/designware-pci.txt.
+
+Additional properties are described here:
+
+Required properties:
+- compatible:
+	should contain "amlogic,axg-pcie" to identify the core.
+- reg:
+	Should contain the configuration address space.
+- reg-names: Must be
+	- "elbi"	External local bus interface registers
+	- "cfg"		Meson specific registers
+	- "config"	PCIe configuration space
+- reset-gpios: The GPIO to generate PCIe PERST# assert and deassert signal.
+- clocks: Must contain an entry for each entry in clock-names.
+- clock-names: Must include the following entries:
+	- "pclk"       PCIe GEN 100M PLL clock
+	- "port"       PCIe_x(A or B) RC clock gate
+	- "general"    PCIe Phy clock
+	- "mipi"       PCIe_x(A or B) 100M ref clock gate
+- resets: phandle to the reset lines.
+- reset-names: must contain "phy" and "peripheral"
+       - "port" Port A or B reset
+       - "apb" APB reset
+
+Example configuration:
+
+	pcie: pcie at f9800000 {
+			compatible = "amlogic,axg-pcie", "snps,dw-pcie";
+			reg = <0x0 0xf9800000 0x0 0x400000
+					0x0 0xff646000 0x0 0x2000
+					0x0 0xf9f00000 0x0 0x100000>;
+			reg-names = "elbi", "cfg", "config";
+			reset-gpios = <&gpio GPIOX_19 GPIO_ACTIVE_HIGH>;
+			interrupts = <GIC_SPI 177 IRQ_TYPE_EDGE_RISING>;
+			#interrupt-cells = <1>;
+			interrupt-map-mask = <0 0 0 0>;
+			interrupt-map = <0 0 0 0 &gic GIC_SPI 179 IRQ_TYPE_EDGE_RISING>;
+			bus-range = <0x0 0xff>;
+			#address-cells = <3>;
+			#size-cells = <2>;
+			device_type = "pci";
+			phys = <&pcie_phy>;
+			ranges = <0x82000000 0 0 0x0 0xf9c00000 0 0x00300000>;
+
+			clocks = <&clkc CLKID_USB
+					&clkc CLKID_MIPI_ENABLE
+					&clkc CLKID_PCIE_A
+					&clkc CLKID_PCIE_CML_EN0>;
+			clock-names = "general",
+					"mipi",
+					"pclk",
+					"port";
+			resets = <&reset RESET_PCIE_A>,
+				<&reset RESET_PCIE_APB>;
+			reset-names = "port",
+					"apb";
+	};
-- 
2.7.4

[PATCH v2 1/2] dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller

[Jerome Brunet]

On Fri, 2018-08-24 at 15:36 +0800, Hanjie Lin wrote:
> From: Yue Wang <yue.wang@amlogic.com>
> 
> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
> PCI core. This patch adds documentation for the DT bindings in Meson PCIe
> controller.
> 
> Signed-off-by: Yue Wang <yue.wang@amlogic.com>
> Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
> ---
>  .../devicetree/bindings/pci/amlogic,meson-pcie.txt | 63 ++++++++++++++++++++++
>  1 file changed, 63 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> 
> diff --git a/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> new file mode 100644
> index 0000000..8a831d1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> @@ -0,0 +1,63 @@
> +Amlogic Meson AXG DWC PCIE SoC controller
> +
> +Amlogic Meson PCIe host controller is based on the Synopsys DesignWare PCI core.
> +It shares common functions with the PCIe DesignWare core driver and
> +inherits common properties defined in
> +Documentation/devicetree/bindings/pci/designware-pci.txt.
> +
> +Additional properties are described here:
> +
> +Required properties:
> +- compatible:
> +	should contain "amlogic,axg-pcie" to identify the core.
> +- reg:
> +	Should contain the configuration address space.
> +- reg-names: Must be
> +	- "elbi"	External local bus interface registers
> +	- "cfg"		Meson specific registers
> +	- "config"	PCIe configuration space
> +- reset-gpios: The GPIO to generate PCIe PERST# assert and deassert signal.
> +- clocks: Must contain an entry for each entry in clock-names.
> +- clock-names: Must include the following entries:
> +	- "pclk"       PCIe GEN 100M PLL clock
> +	- "port"       PCIe_x(A or B) RC clock gate
> +	- "general"    PCIe Phy clock
> +	- "mipi"       PCIe_x(A or B) 100M ref clock gate
> +- resets: phandle to the reset lines.
> +- reset-names: must contain "phy" and "peripheral"
> +       - "port" Port A or B reset
> +       - "apb" APB reset

The above description is not coherent (phy <=> port)

> +
> +Example configuration:
> +
> +	pcie: pcie at f9800000 {
> +			compatible = "amlogic,axg-pcie", "snps,dw-pcie";
> +			reg = <0x0 0xf9800000 0x0 0x400000
> +					0x0 0xff646000 0x0 0x2000
> +					0x0 0xf9f00000 0x0 0x100000>;
> +			reg-names = "elbi", "cfg", "config";
> +			reset-gpios = <&gpio GPIOX_19 GPIO_ACTIVE_HIGH>;
> +			interrupts = <GIC_SPI 177 IRQ_TYPE_EDGE_RISING>;
> +			#interrupt-cells = <1>;
> +			interrupt-map-mask = <0 0 0 0>;
> +			interrupt-map = <0 0 0 0 &gic GIC_SPI 179 IRQ_TYPE_EDGE_RISING>;
> +			bus-range = <0x0 0xff>;
> +			#address-cells = <3>;
> +			#size-cells = <2>;
> +			device_type = "pci";

Not described above - is it even used ?

> +			phys = <&pcie_phy>;

Not documented and not necessary. Please remove this.

> +			ranges = <0x82000000 0 0 0x0 0xf9c00000 0 0x00300000>;
> +
> +			clocks = <&clkc CLKID_USB
> +					&clkc CLKID_MIPI_ENABLE
> +					&clkc CLKID_PCIE_A
> +					&clkc CLKID_PCIE_CML_EN0>;
> +			clock-names = "general",
> +					"mipi",
> +					"pclk",
> +					"port";
> +			resets = <&reset RESET_PCIE_A>,
> +				<&reset RESET_PCIE_APB>;
> +			reset-names = "port",
> +					"apb";
> +	};

[PATCH v2 1/2] dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller

[Hanjie Lin]

On 2018/8/24 16:22, Jerome Brunet wrote:
> On Fri, 2018-08-24 at 15:36 +0800, Hanjie Lin wrote:
>> From: Yue Wang <yue.wang@amlogic.com>
>>
>> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
>> PCI core. This patch adds documentation for the DT bindings in Meson PCIe
>> controller.
>>
>> Signed-off-by: Yue Wang <yue.wang@amlogic.com>
>> Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
>> ---
>>  .../devicetree/bindings/pci/amlogic,meson-pcie.txt | 63 ++++++++++++++++++++++
>>  1 file changed, 63 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
>>
>> diff --git a/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
>> new file mode 100644
>> index 0000000..8a831d1
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
>> @@ -0,0 +1,63 @@
>> +Amlogic Meson AXG DWC PCIE SoC controller
>> +
>> +Amlogic Meson PCIe host controller is based on the Synopsys DesignWare PCI core.
>> +It shares common functions with the PCIe DesignWare core driver and
>> +inherits common properties defined in
>> +Documentation/devicetree/bindings/pci/designware-pci.txt.
>> +
>> +Additional properties are described here:
>> +
>> +Required properties:
>> +- compatible:
>> +	should contain "amlogic,axg-pcie" to identify the core.
>> +- reg:
>> +	Should contain the configuration address space.
>> +- reg-names: Must be
>> +	- "elbi"	External local bus interface registers
>> +	- "cfg"		Meson specific registers
>> +	- "config"	PCIe configuration space
>> +- reset-gpios: The GPIO to generate PCIe PERST# assert and deassert signal.
>> +- clocks: Must contain an entry for each entry in clock-names.
>> +- clock-names: Must include the following entries:
>> +	- "pclk"       PCIe GEN 100M PLL clock
>> +	- "port"       PCIe_x(A or B) RC clock gate
>> +	- "general"    PCIe Phy clock
>> +	- "mipi"       PCIe_x(A or B) 100M ref clock gate
>> +- resets: phandle to the reset lines.
>> +- reset-names: must contain "phy" and "peripheral"
>> +       - "port" Port A or B reset
>> +       - "apb" APB reset
> 
> The above description is not coherent (phy <=> port)
> 

Yes, this should be port and apb here.
We'll integrate phy driver into ctrl driver, and move phy reset to here also.

>> +
>> +Example configuration:
>> +
>> +	pcie: pcie at f9800000 {
>> +			compatible = "amlogic,axg-pcie", "snps,dw-pcie";
>> +			reg = <0x0 0xf9800000 0x0 0x400000
>> +					0x0 0xff646000 0x0 0x2000
>> +					0x0 0xf9f00000 0x0 0x100000>;
>> +			reg-names = "elbi", "cfg", "config";
>> +			reset-gpios = <&gpio GPIOX_19 GPIO_ACTIVE_HIGH>;
>> +			interrupts = <GIC_SPI 177 IRQ_TYPE_EDGE_RISING>;
>> +			#interrupt-cells = <1>;
>> +			interrupt-map-mask = <0 0 0 0>;
>> +			interrupt-map = <0 0 0 0 &gic GIC_SPI 179 IRQ_TYPE_EDGE_RISING>;
>> +			bus-range = <0x0 0xff>;
>> +			#address-cells = <3>;
>> +			#size-cells = <2>;
>> +			device_type = "pci";
> 
> Not described above - is it even used ?
> 

It's necessary, specified in designware-pcie.txt:
 - device_type:
  Usage: required
  Value type: <string>
  Definition: Should be "pci". 

>> +			phys = <&pcie_phy>;
> 
> Not documented and not necessary. Please remove this.
> 

We'll remove phy driver and this also.

>> +			ranges = <0x82000000 0 0 0x0 0xf9c00000 0 0x00300000>;
>> +
>> +			clocks = <&clkc CLKID_USB
>> +					&clkc CLKID_MIPI_ENABLE
>> +					&clkc CLKID_PCIE_A
>> +					&clkc CLKID_PCIE_CML_EN0>;
>> +			clock-names = "general",
>> +					"mipi",
>> +					"pclk",
>> +					"port";
>> +			resets = <&reset RESET_PCIE_A>,
>> +				<&reset RESET_PCIE_APB>;
>> +			reset-names = "port",
>> +					"apb";
>> +	};
> 
> 
> .
> 

[PATCH v2 1/2] dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller

[Rob Herring]

On Mon, Aug 27, 2018 at 04:55:20PM +0800, Hanjie Lin wrote:
> 
> 
> On 2018/8/24 16:22, Jerome Brunet wrote:
> > On Fri, 2018-08-24 at 15:36 +0800, Hanjie Lin wrote:
> >> From: Yue Wang <yue.wang@amlogic.com>
> >>
> >> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
> >> PCI core. This patch adds documentation for the DT bindings in Meson PCIe
> >> controller.
> >>
> >> Signed-off-by: Yue Wang <yue.wang@amlogic.com>
> >> Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
> >> ---
> >>  .../devicetree/bindings/pci/amlogic,meson-pcie.txt | 63 ++++++++++++++++++++++
> >>  1 file changed, 63 insertions(+)
> >>  create mode 100644 Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> >>
> >> diff --git a/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> >> new file mode 100644
> >> index 0000000..8a831d1
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> >> @@ -0,0 +1,63 @@
> >> +Amlogic Meson AXG DWC PCIE SoC controller
> >> +
> >> +Amlogic Meson PCIe host controller is based on the Synopsys DesignWare PCI core.
> >> +It shares common functions with the PCIe DesignWare core driver and
> >> +inherits common properties defined in
> >> +Documentation/devicetree/bindings/pci/designware-pci.txt.
> >> +
> >> +Additional properties are described here:
> >> +
> >> +Required properties:
> >> +- compatible:
> >> +	should contain "amlogic,axg-pcie" to identify the core.
> >> +- reg:
> >> +	Should contain the configuration address space.
> >> +- reg-names: Must be
> >> +	- "elbi"	External local bus interface registers
> >> +	- "cfg"		Meson specific registers
> >> +	- "config"	PCIe configuration space
> >> +- reset-gpios: The GPIO to generate PCIe PERST# assert and deassert signal.
> >> +- clocks: Must contain an entry for each entry in clock-names.
> >> +- clock-names: Must include the following entries:
> >> +	- "pclk"       PCIe GEN 100M PLL clock
> >> +	- "port"       PCIe_x(A or B) RC clock gate
> >> +	- "general"    PCIe Phy clock
> >> +	- "mipi"       PCIe_x(A or B) 100M ref clock gate
> >> +- resets: phandle to the reset lines.
> >> +- reset-names: must contain "phy" and "peripheral"
> >> +       - "port" Port A or B reset
> >> +       - "apb" APB reset
> > 
> > The above description is not coherent (phy <=> port)
> > 
> 
> Yes, this should be port and apb here.
> We'll integrate phy driver into ctrl driver, and move phy reset to here also.

Why? That's the wrong thing to do if they are separate h/w blocks. You 
can do whatever you like in the drivers, but the DT should reflect the 
h/w.

Rob

[PATCH v2 1/2] dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller

[Hanjie Lin]

On 2018/8/29 8:41, Rob Herring wrote:
> On Mon, Aug 27, 2018 at 04:55:20PM +0800, Hanjie Lin wrote:
>>
>>
>> On 2018/8/24 16:22, Jerome Brunet wrote:
>>> On Fri, 2018-08-24 at 15:36 +0800, Hanjie Lin wrote:
>>>> From: Yue Wang <yue.wang@amlogic.com>
>>>>
>>>> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
>>>> PCI core. This patch adds documentation for the DT bindings in Meson PCIe
>>>> controller.
>>>>
>>>> Signed-off-by: Yue Wang <yue.wang@amlogic.com>
>>>> Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
>>>> ---
>>>>  .../devicetree/bindings/pci/amlogic,meson-pcie.txt | 63 ++++++++++++++++++++++
>>>>  1 file changed, 63 insertions(+)
>>>>  create mode 100644 Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
>>>> new file mode 100644
>>>> index 0000000..8a831d1
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
>>>> @@ -0,0 +1,63 @@
>>>> +Amlogic Meson AXG DWC PCIE SoC controller
>>>> +
>>>> +Amlogic Meson PCIe host controller is based on the Synopsys DesignWare PCI core.
>>>> +It shares common functions with the PCIe DesignWare core driver and
>>>> +inherits common properties defined in
>>>> +Documentation/devicetree/bindings/pci/designware-pci.txt.
>>>> +
>>>> +Additional properties are described here:
>>>> +
>>>> +Required properties:
>>>> +- compatible:
>>>> +	should contain "amlogic,axg-pcie" to identify the core.
>>>> +- reg:
>>>> +	Should contain the configuration address space.
>>>> +- reg-names: Must be
>>>> +	- "elbi"	External local bus interface registers
>>>> +	- "cfg"		Meson specific registers
>>>> +	- "config"	PCIe configuration space
>>>> +- reset-gpios: The GPIO to generate PCIe PERST# assert and deassert signal.
>>>> +- clocks: Must contain an entry for each entry in clock-names.
>>>> +- clock-names: Must include the following entries:
>>>> +	- "pclk"       PCIe GEN 100M PLL clock
>>>> +	- "port"       PCIe_x(A or B) RC clock gate
>>>> +	- "general"    PCIe Phy clock
>>>> +	- "mipi"       PCIe_x(A or B) 100M ref clock gate
>>>> +- resets: phandle to the reset lines.
>>>> +- reset-names: must contain "phy" and "peripheral"
>>>> +       - "port" Port A or B reset
>>>> +       - "apb" APB reset
>>>
>>> The above description is not coherent (phy <=> port)
>>>
>>
>> Yes, this should be port and apb here.
>> We'll integrate phy driver into ctrl driver, and move phy reset to here also.
> 
> Why? That's the wrong thing to do if they are separate h/w blocks. You 
> can do whatever you like in the drivers, but the DT should reflect the 
> h/w.
> 
> Rob
> 
> .
> 

We have the dedicated phy driver which only process reset job,
and we consider that it's too overkill to do just these things .
So we will integrate phy reset job into the controller driver int the next version.  

thanks. 

[PATCH v2 1/2] dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller

[Jerome Brunet]

On Thu, 2018-08-30 at 15:37 +0800, Hanjie Lin wrote:
> 
> On 2018/8/29 8:41, Rob Herring wrote:
> > On Mon, Aug 27, 2018 at 04:55:20PM +0800, Hanjie Lin wrote:
> > > 
> > > 
> > > On 2018/8/24 16:22, Jerome Brunet wrote:
> > > > On Fri, 2018-08-24 at 15:36 +0800, Hanjie Lin wrote:
> > > > > From: Yue Wang <yue.wang@amlogic.com>
> > > > > 
> > > > > The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
> > > > > PCI core. This patch adds documentation for the DT bindings in Meson PCIe
> > > > > controller.
> > > > > 
> > > > > Signed-off-by: Yue Wang <yue.wang@amlogic.com>
> > > > > Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
> > > > > ---
> > > > >  .../devicetree/bindings/pci/amlogic,meson-pcie.txt | 63 ++++++++++++++++++++++
> > > > >  1 file changed, 63 insertions(+)
> > > > >  create mode 100644 Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> > > > > 
> > > > > diff --git a/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> > > > > new file mode 100644
> > > > > index 0000000..8a831d1
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> > > > > @@ -0,0 +1,63 @@
> > > > > +Amlogic Meson AXG DWC PCIE SoC controller
> > > > > +
> > > > > +Amlogic Meson PCIe host controller is based on the Synopsys DesignWare PCI core.
> > > > > +It shares common functions with the PCIe DesignWare core driver and
> > > > > +inherits common properties defined in
> > > > > +Documentation/devicetree/bindings/pci/designware-pci.txt.
> > > > > +
> > > > > +Additional properties are described here:
> > > > > +
> > > > > +Required properties:
> > > > > +- compatible:
> > > > > +	should contain "amlogic,axg-pcie" to identify the core.
> > > > > +- reg:
> > > > > +	Should contain the configuration address space.
> > > > > +- reg-names: Must be
> > > > > +	- "elbi"	External local bus interface registers
> > > > > +	- "cfg"		Meson specific registers
> > > > > +	- "config"	PCIe configuration space
> > > > > +- reset-gpios: The GPIO to generate PCIe PERST# assert and deassert signal.
> > > > > +- clocks: Must contain an entry for each entry in clock-names.
> > > > > +- clock-names: Must include the following entries:
> > > > > +	- "pclk"       PCIe GEN 100M PLL clock
> > > > > +	- "port"       PCIe_x(A or B) RC clock gate
> > > > > +	- "general"    PCIe Phy clock
> > > > > +	- "mipi"       PCIe_x(A or B) 100M ref clock gate
> > > > > +- resets: phandle to the reset lines.
> > > > > +- reset-names: must contain "phy" and "peripheral"
> > > > > +       - "port" Port A or B reset
> > > > > +       - "apb" APB reset
> > > > 
> > > > The above description is not coherent (phy <=> port)
> > > > 
> > > 
> > > Yes, this should be port and apb here.
> > > We'll integrate phy driver into ctrl driver, and move phy reset to here also.
> > 
> > Why? That's the wrong thing to do if they are separate h/w blocks. You 
> > can do whatever you like in the drivers, but the DT should reflect the 
> > h/w.
> > 
> > Rob
> > 
> > .
> > 
> 
> We have the dedicated phy driver which only process reset job,
> and we consider that it's too overkill to do just these things .
> So we will integrate phy reset job into the controller driver int the next version.

Rob has a point there. Even if overkill, it does model the HW as it is.
+ I spotted in your v2 that there is also a register access, so not only the
reset

> 
> thanks. 

[PATCH v2 1/2] dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller

[Rob Herring]

On Thu, Aug 30, 2018 at 2:37 AM Hanjie Lin <hanjie.lin@amlogic.com> wrote:
>
>
>
> On 2018/8/29 8:41, Rob Herring wrote:
> > On Mon, Aug 27, 2018 at 04:55:20PM +0800, Hanjie Lin wrote:
> >>
> >>
> >> On 2018/8/24 16:22, Jerome Brunet wrote:
> >>> On Fri, 2018-08-24 at 15:36 +0800, Hanjie Lin wrote:
> >>>> From: Yue Wang <yue.wang@amlogic.com>
> >>>>
> >>>> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
> >>>> PCI core. This patch adds documentation for the DT bindings in Meson PCIe
> >>>> controller.
> >>>>
> >>>> Signed-off-by: Yue Wang <yue.wang@amlogic.com>
> >>>> Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
> >>>> ---
> >>>>  .../devicetree/bindings/pci/amlogic,meson-pcie.txt | 63 ++++++++++++++++++++++
> >>>>  1 file changed, 63 insertions(+)
> >>>>  create mode 100644 Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> >>>>
> >>>> diff --git a/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> >>>> new file mode 100644
> >>>> index 0000000..8a831d1
> >>>> --- /dev/null
> >>>> +++ b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
> >>>> @@ -0,0 +1,63 @@
> >>>> +Amlogic Meson AXG DWC PCIE SoC controller
> >>>> +
> >>>> +Amlogic Meson PCIe host controller is based on the Synopsys DesignWare PCI core.
> >>>> +It shares common functions with the PCIe DesignWare core driver and
> >>>> +inherits common properties defined in
> >>>> +Documentation/devicetree/bindings/pci/designware-pci.txt.
> >>>> +
> >>>> +Additional properties are described here:
> >>>> +
> >>>> +Required properties:
> >>>> +- compatible:
> >>>> +  should contain "amlogic,axg-pcie" to identify the core.
> >>>> +- reg:
> >>>> +  Should contain the configuration address space.
> >>>> +- reg-names: Must be
> >>>> +  - "elbi"        External local bus interface registers
> >>>> +  - "cfg"         Meson specific registers
> >>>> +  - "config"      PCIe configuration space
> >>>> +- reset-gpios: The GPIO to generate PCIe PERST# assert and deassert signal.
> >>>> +- clocks: Must contain an entry for each entry in clock-names.
> >>>> +- clock-names: Must include the following entries:
> >>>> +  - "pclk"       PCIe GEN 100M PLL clock
> >>>> +  - "port"       PCIe_x(A or B) RC clock gate
> >>>> +  - "general"    PCIe Phy clock
> >>>> +  - "mipi"       PCIe_x(A or B) 100M ref clock gate
> >>>> +- resets: phandle to the reset lines.
> >>>> +- reset-names: must contain "phy" and "peripheral"
> >>>> +       - "port" Port A or B reset
> >>>> +       - "apb" APB reset
> >>>
> >>> The above description is not coherent (phy <=> port)
> >>>
> >>
> >> Yes, this should be port and apb here.
> >> We'll integrate phy driver into ctrl driver, and move phy reset to here also.
> >
> > Why? That's the wrong thing to do if they are separate h/w blocks. You
> > can do whatever you like in the drivers, but the DT should reflect the
> > h/w.
> >
> > Rob
> >
> > .
> >
>
> We have the dedicated phy driver which only process reset job,
> and we consider that it's too overkill to do just these things .
> So we will integrate phy reset job into the controller driver int the next version.

What's in the separate register space you had for the phy?

Rob

[PATCH v2 1/2] dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller

[Hanjie Lin]

On 2018/8/30 21:59, Rob Herring wrote:
> On Thu, Aug 30, 2018 at 2:37 AM Hanjie Lin <hanjie.lin@amlogic.com> wrote:
>>
>>
>>
>> On 2018/8/29 8:41, Rob Herring wrote:
>>> On Mon, Aug 27, 2018 at 04:55:20PM +0800, Hanjie Lin wrote:
>>>>
>>>>
>>>> On 2018/8/24 16:22, Jerome Brunet wrote:
>>>>> On Fri, 2018-08-24 at 15:36 +0800, Hanjie Lin wrote:
>>>>>> From: Yue Wang <yue.wang@amlogic.com>
>>>>>>
>>>>>> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
>>>>>> PCI core. This patch adds documentation for the DT bindings in Meson PCIe
>>>>>> controller.
>>>>>>
>>>>>> Signed-off-by: Yue Wang <yue.wang@amlogic.com>
>>>>>> Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
>>>>>> ---
>>>>>>  .../devicetree/bindings/pci/amlogic,meson-pcie.txt | 63 ++++++++++++++++++++++
>>>>>>  1 file changed, 63 insertions(+)
>>>>>>  create mode 100644 Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
>>>>>>
>>>>>> diff --git a/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
>>>>>> new file mode 100644
>>>>>> index 0000000..8a831d1
>>>>>> --- /dev/null
>>>>>> +++ b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
>>>>>> @@ -0,0 +1,63 @@
>>>>>> +Amlogic Meson AXG DWC PCIE SoC controller
>>>>>> +
>>>>>> +Amlogic Meson PCIe host controller is based on the Synopsys DesignWare PCI core.
>>>>>> +It shares common functions with the PCIe DesignWare core driver and
>>>>>> +inherits common properties defined in
>>>>>> +Documentation/devicetree/bindings/pci/designware-pci.txt.
>>>>>> +
>>>>>> +Additional properties are described here:
>>>>>> +
>>>>>> +Required properties:
>>>>>> +- compatible:
>>>>>> +  should contain "amlogic,axg-pcie" to identify the core.
>>>>>> +- reg:
>>>>>> +  Should contain the configuration address space.
>>>>>> +- reg-names: Must be
>>>>>> +  - "elbi"        External local bus interface registers
>>>>>> +  - "cfg"         Meson specific registers
>>>>>> +  - "config"      PCIe configuration space
>>>>>> +- reset-gpios: The GPIO to generate PCIe PERST# assert and deassert signal.
>>>>>> +- clocks: Must contain an entry for each entry in clock-names.
>>>>>> +- clock-names: Must include the following entries:
>>>>>> +  - "pclk"       PCIe GEN 100M PLL clock
>>>>>> +  - "port"       PCIe_x(A or B) RC clock gate
>>>>>> +  - "general"    PCIe Phy clock
>>>>>> +  - "mipi"       PCIe_x(A or B) 100M ref clock gate
>>>>>> +- resets: phandle to the reset lines.
>>>>>> +- reset-names: must contain "phy" and "peripheral"
>>>>>> +       - "port" Port A or B reset
>>>>>> +       - "apb" APB reset
>>>>>
>>>>> The above description is not coherent (phy <=> port)
>>>>>
>>>>
>>>> Yes, this should be port and apb here.
>>>> We'll integrate phy driver into ctrl driver, and move phy reset to here also.
>>>
>>> Why? That's the wrong thing to do if they are separate h/w blocks. You
>>> can do whatever you like in the drivers, but the DT should reflect the
>>> h/w.
>>>
>>> Rob
>>>
>>> .
>>>
>>
>> We have the dedicated phy driver which only process reset job,
>> and we consider that it's too overkill to do just these things .
>> So we will integrate phy reset job into the controller driver int the next version.
> 
> What's in the separate register space you had for the phy?
> 
> Rob
> 
> .
> 

As described with 'phy' reg in ctrl patch v3 thread [0]

- reg-names: Must be
	- "elbi"	External local bus interface registers
	- "cfg"		Meson specific registers
	- "phy"		Meson PCIE PHY registers
	- "config"	PCIe configuration space

When each controller driver probe, we powerup phy by write phy register like below: 
writel(MESON_PCIE_PHY_POWERUP, mp->mem_res.phy_base);

[0] https://lkml.kernel.org/r/1535616829-167936-1-git-send-email-hanjie.lin at amlogic.com

[PATCH v2 2/2] PCI: meson: add the Amlogic Meson PCIe controller driver

[Hanjie Lin]

From: Yue Wang <yue.wang@amlogic.com>

The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
PCI core. This patch adds the driver support for Meson PCIe controller.

Signed-off-by: Yue Wang <yue.wang@amlogic.com>
Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
---
 drivers/pci/controller/dwc/Kconfig     |  12 +
 drivers/pci/controller/dwc/Makefile    |   1 +
 drivers/pci/controller/dwc/pci-meson.c | 613 +++++++++++++++++++++++++++++++++
 3 files changed, 626 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pci-meson.c

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 91b0194..6cb36f6 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -193,4 +193,16 @@ config PCIE_HISI_STB
 	help
           Say Y here if you want PCIe controller support on HiSilicon STB SoCs
 
+config PCI_MESON
+	bool "MESON PCIe controller"
+	depends on PCI
+	depends on PCI_MSI_IRQ_DOMAIN
+	select PCIEPORTBUS
+	select PCIE_DW_HOST
+	help
+	  Say Y here if you want to enable PCI controller support on Amlogic
+	  SoCs. The PCI controller on Amlogic is based on DesignWare hardware
+	  and therefore the driver re-uses the DesignWare core functions to
+	  implement the driver.
+
 endmenu
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index 5d2ce72..cf676bd 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
 obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
 obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o
 obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
+obj-$(CONFIG_PCI_MESON) += pci-meson.o
 
 # The following drivers are for devices that use the generic ACPI
 # pci_root.c driver but don't support standard ECAM config access.
diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c
new file mode 100644
index 0000000..a9edf20
--- /dev/null
+++ b/drivers/pci/controller/dwc/pci-meson.c
@@ -0,0 +1,613 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for Amlogic MESON SoCs
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Yue Wang <yue.wang@amlogic.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+#include <linux/resource.h>
+#include <linux/types.h>
+#include <linux/reset.h>
+
+#include "pcie-designware.h"
+
+#define to_meson_pcie(x) dev_get_drvdata((x)->dev)
+
+/* External local bus interface registers */
+#define PLR_OFFSET			0x700
+#define PCIE_PORT_LINK_CTRL_OFF		(PLR_OFFSET + 0x10)
+#define FAST_LINK_MODE			BIT(7)
+#define LINK_CAPABLE_MASK		GENMASK(21, 16)
+#define LINK_CAPABLE_X1			BIT(16)
+
+#define PCIE_GEN2_CTRL_OFF		(PLR_OFFSET + 0x10c)
+#define NUM_OF_LANES_MASK		GENMASK(12, 8)
+#define NUM_OF_LANES_X1			BIT(8)
+#define DIRECT_SPEED_CHANGE		BIT(17)
+
+#define TYPE1_HDR_OFFSET		0x0
+#define PCIE_STATUS_COMMAND		(TYPE1_HDR_OFFSET + 0x04)
+#define PCI_IO_EN			BIT(0)
+#define PCI_MEM_SPACE_EN		BIT(1)
+#define PCI_BUS_MASTER_EN		BIT(2)
+
+#define PCIE_BASE_ADDR0			(TYPE1_HDR_OFFSET + 0x10)
+#define PCIE_BASE_ADDR1			(TYPE1_HDR_OFFSET + 0x14)
+
+#define PCIE_CAP_OFFSET			0x70
+#define PCIE_DEV_CTRL_DEV_STUS		(PCIE_CAP_OFFSET + 0x08)
+#define PCIE_CAP_MAX_PAYLOAD_MASK	GENMASK(7, 5)
+#define PCIE_CAP_MAX_PAYLOAD_SIZE(x)	((x) << 5)
+#define PCIE_CAP_MAX_READ_REQ_MASK	GENMASK(14, 12)
+#define PCIE_CAP_MAX_READ_REQ_SIZE(x)	((x) << 12)
+
+#define PCI_CLASS_REVISION_MASK		GENMASK(7, 0)
+
+/* PCIe specific config registers */
+#define PCIE_CFG0			0x0
+#define APP_LTSSM_ENABLE		BIT(7)
+
+#define PCIE_CFG_STATUS12		0x30
+#define IS_SMLH_LINK_UP(x)		((x) & (1 << 6))
+#define IS_RDLH_LINK_UP(x)		((x) & (1 << 16))
+#define IS_LTSSM_UP(x)			((((x) >> 10) & 0x1f) == 0x11)
+
+#define PCIE_CFG_STATUS17		0x44
+#define PM_CURRENT_STATE(x)		(((x) >> 7) & 0x1)
+
+#define WAIT_LINKUP_TIMEOUT		2000
+#define PORT_CLK_RATE			100000000UL
+#define MAX_PAYLOAD_SIZE		256
+#define MAX_READ_REQ_SIZE		256
+
+enum pcie_data_rate {
+	PCIE_GEN1,
+	PCIE_GEN2,
+	PCIE_GEN3,
+	PCIE_GEN4
+};
+
+struct meson_pcie_mem_res {
+	void __iomem *elbi_base; /* DT 0th resource */
+	void __iomem *cfg_base; /* DT 2nd resource */
+};
+
+struct meson_pcie_clk_res {
+	struct clk *clk;
+	struct clk *mipi_gate;
+	struct clk *port_clk;
+	struct clk *general_clk;
+};
+
+struct meson_pcie_rc_reset {
+	struct reset_control *port;
+	struct reset_control *apb;
+};
+
+struct meson_pcie {
+	struct dw_pcie pci;
+	struct meson_pcie_mem_res mem_res;
+	struct meson_pcie_clk_res clk_res;
+	struct meson_pcie_rc_reset mrst;
+	struct gpio_desc *reset_gpio;
+
+	struct phy *phy;
+	enum of_gpio_flags gpio_flag;
+	int pcie_num;
+	u32 port_num;
+	u32 device_attch;
+};
+
+static int meson_pcie_get_mem(struct platform_device *pdev,
+			      struct meson_pcie *mp)
+{
+	struct device *dev = mp->pci.dev;
+	struct resource *res;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
+	if (!res)
+		return -ENODEV;
+
+	mp->mem_res.elbi_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(mp->mem_res.elbi_base))
+		return PTR_ERR(mp->mem_res.elbi_base);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
+	if (!res)
+		return -ENODEV;
+
+	mp->mem_res.cfg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(mp->mem_res.cfg_base))
+		return PTR_ERR(mp->mem_res.cfg_base);
+
+	return 0;
+}
+
+static void meson_pcie_rc_reset(struct meson_pcie *mp)
+{
+	struct meson_pcie_rc_reset *mrst = &mp->mrst;
+
+	reset_control_assert(mrst->port);
+	reset_control_assert(mrst->apb);
+	udelay(400);
+	reset_control_deassert(mrst->port);
+	reset_control_deassert(mrst->apb);
+	udelay(500);
+}
+
+static int meson_pcie_init_clk(struct meson_pcie *mp)
+{
+	struct device *dev = mp->pci.dev;
+	struct meson_pcie_clk_res *res = &mp->clk_res;
+	int ret;
+
+	res->port_clk = devm_clk_get(dev, "port");
+	if (IS_ERR(res->port_clk)) {
+		if (PTR_ERR(res->port_clk) != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get pcie port clock\n");
+
+		return PTR_ERR(res->port_clk);
+	}
+
+	res->mipi_gate = devm_clk_get(dev, "pcie_mipi_en");
+	if (IS_ERR(res->mipi_gate)) {
+		if (PTR_ERR(res->mipi_gate) != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get pcie mipi clock\n");
+
+		return PTR_ERR(res->mipi_gate);
+	}
+
+	res->general_clk = devm_clk_get(dev, "pcie_general");
+	if (IS_ERR(res->general_clk)) {
+		if (PTR_ERR(res->general_clk) != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get pcie general clock\n");
+
+		return PTR_ERR(res->general_clk);
+	}
+
+	res->clk = devm_clk_get(dev, "pcie");
+	if (IS_ERR(res->clk)) {
+		if (PTR_ERR(res->clk) != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get pcie rc clock\n");
+
+		return PTR_ERR(res->clk);
+	}
+
+	phy_init(mp->phy);
+	meson_pcie_rc_reset(mp);
+
+	ret = clk_set_rate(res->port_clk, PORT_CLK_RATE);
+	if (ret) {
+		dev_err(dev, "set bus clk rate failed, ret = %d", ret);
+		goto err_clk;
+	}
+
+	ret = clk_prepare_enable(res->port_clk);
+	if (ret) {
+		dev_err(dev, "cannot enable pcie port clock");
+		goto err_clk;
+	}
+
+	ret = clk_prepare_enable(res->mipi_gate);
+	if (ret) {
+		dev_err(dev, "cannot enable pcie mipi gate clock");
+		goto err_port_clk;
+	}
+
+	ret = clk_prepare_enable(res->general_clk);
+	if (ret) {
+		dev_err(dev, "cannot enable pcie general clock");
+		goto err_mipi_gate;
+	}
+
+	ret = clk_prepare_enable(res->clk);
+	if (ret) {
+		dev_err(dev, "cannot enable pcie rc clock");
+		goto err_general_clk;
+	}
+
+	return 0;
+
+err_general_clk:
+	clk_disable_unprepare(res->general_clk);
+err_mipi_gate:
+	clk_disable_unprepare(res->mipi_gate);
+err_port_clk:
+	clk_disable_unprepare(res->port_clk);
+err_clk:
+	return ret;
+}
+
+static void meson_pcie_deinit_clk(struct meson_pcie *mp)
+{
+	clk_disable_unprepare(mp->clk_res.clk);
+	clk_disable_unprepare(mp->clk_res.general_clk);
+	clk_disable_unprepare(mp->clk_res.mipi_gate);
+	clk_disable_unprepare(mp->clk_res.port_clk);
+}
+
+static inline void meson_elb_writel(struct meson_pcie *mp, u32 val, u32 reg)
+{
+	writel(val, mp->mem_res.elbi_base + reg);
+}
+
+static inline u32 meson_elb_readl(struct meson_pcie *mp, u32 reg)
+{
+	return readl(mp->mem_res.elbi_base + reg);
+}
+
+static inline u32 meson_cfg_readl(struct meson_pcie *mp, u32 reg)
+{
+	return readl(mp->mem_res.cfg_base + reg);
+}
+
+static inline void meson_cfg_writel(struct meson_pcie *mp, u32 val, u32 reg)
+{
+	writel(val, mp->mem_res.cfg_base + reg);
+}
+
+static void meson_pcie_assert_reset(struct meson_pcie *mp)
+{
+	gpiod_set_value_cansleep(mp->reset_gpio, 0);
+	udelay(500);
+	gpiod_set_value_cansleep(mp->reset_gpio, 1);
+}
+
+static void meson_pcie_init_dw(struct meson_pcie *mp)
+{
+	u32 val = 0;
+
+	val = meson_cfg_readl(mp, PCIE_CFG0);
+	val |= APP_LTSSM_ENABLE;
+	meson_cfg_writel(mp, val, PCIE_CFG0);
+
+	val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF);
+	val &= ~LINK_CAPABLE_MASK;
+	meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
+
+	val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF);
+	val |= LINK_CAPABLE_X1 | FAST_LINK_MODE;
+	meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
+
+	val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);
+	val &= ~NUM_OF_LANES_MASK;
+	meson_elb_writel(mp, val, PCIE_GEN2_CTRL_OFF);
+
+	val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);
+	val |= NUM_OF_LANES_X1 | DIRECT_SPEED_CHANGE;
+	meson_elb_writel(mp, val, PCIE_GEN2_CTRL_OFF);
+
+	meson_elb_writel(mp, 0x0, PCIE_BASE_ADDR0);
+	meson_elb_writel(mp, 0x0, PCIE_BASE_ADDR1);
+}
+
+static int meson_size_to_payload(int size)
+{
+	if (size & (size - 1) || size < 128 || size > 4096)
+		return 1;
+
+	return fls(size) - 8;
+}
+
+static void meson_set_max_payload(struct meson_pcie *mp, int size)
+{
+	u32 val = 0;
+	int max_payload_size = meson_size_to_payload(size);
+
+	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
+	val &= ~PCIE_CAP_MAX_PAYLOAD_MASK;
+	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
+
+	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
+	val |= PCIE_CAP_MAX_PAYLOAD_SIZE(max_payload_size);
+	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
+}
+
+static void meson_set_max_rd_req_size(struct meson_pcie *mp, int size)
+{
+	u32 val = 0;
+	int max_rd_req_size = meson_size_to_payload(size);
+
+	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
+	val &= ~PCIE_CAP_MAX_READ_REQ_MASK;
+	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
+
+	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
+	val |= PCIE_CAP_MAX_READ_REQ_SIZE(max_rd_req_size);
+	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
+}
+
+static inline void meson_enable_memory_space(struct meson_pcie *mp)
+{
+	/* Set the RC Bus Master, Memory Space and I/O Space enables */
+	meson_elb_writel(mp, PCI_IO_EN | PCI_MEM_SPACE_EN | PCI_BUS_MASTER_EN,
+			 PCIE_STATUS_COMMAND);
+}
+
+static int meson_pcie_establish_link(struct meson_pcie *mp)
+{
+	struct dw_pcie *pci = &mp->pci;
+	struct pcie_port *pp = &pci->pp;
+
+	meson_pcie_init_dw(mp);
+	meson_set_max_payload(mp, MAX_PAYLOAD_SIZE);
+	meson_set_max_rd_req_size(mp, MAX_READ_REQ_SIZE);
+
+	dw_pcie_setup_rc(pp);
+	meson_enable_memory_space(mp);
+
+	meson_pcie_assert_reset(mp);
+
+	/* check if the link is up or not */
+	if (!dw_pcie_wait_for_link(pci))
+		return 0;
+
+	return -ETIMEDOUT;
+}
+
+static void meson_pcie_msi_init(struct meson_pcie *mp)
+{
+	struct pcie_port *pp = &mp->pci.pp;
+
+	dw_pcie_msi_init(pp);
+}
+
+static void meson_pcie_enable_interrupts(struct meson_pcie *mp)
+{
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		meson_pcie_msi_init(mp);
+}
+
+static u32 meson_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base,
+			       u32 reg, size_t size)
+{
+	u32 val;
+
+	dw_pcie_read(base + reg, size, &val);
+
+	return val;
+}
+
+static void meson_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base,
+				 u32 reg, size_t size, u32 val)
+{
+	dw_pcie_write(base + reg, size, val);
+}
+
+static int meson_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
+				  u32 *val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct meson_pcie *mp = to_meson_pcie(pci);
+
+	if (!mp->device_attch)
+		return 0;
+
+	/* the device class is not reported correctly from the register */
+	if (where == PCI_CLASS_REVISION) {
+		*val = readl(pci->dbi_base + PCI_CLASS_REVISION);
+		/* keep revision id */
+		*val &= PCI_CLASS_REVISION_MASK;
+		*val |= PCI_CLASS_BRIDGE_PCI << 16;
+		return PCIBIOS_SUCCESSFUL;
+	}
+
+	return dw_pcie_read(pci->dbi_base + where, size, val);
+}
+
+static int meson_pcie_wr_own_conf(struct pcie_port *pp, int where,
+				  int size, u32 val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct meson_pcie *mp = to_meson_pcie(pci);
+
+	if (!mp->device_attch)
+		return 0;
+
+	return dw_pcie_write(pci->dbi_base + where, size, val);
+}
+
+static int meson_pcie_link_up(struct dw_pcie *pci)
+{
+	struct meson_pcie *mp = to_meson_pcie(pci);
+	struct device *dev = pci->dev;
+	u32 smlh_up = 0;
+	u32 ltssm_up = 0;
+	u32 rdlh_up = 0;
+	u32 speed_okay = 0;
+	u32 cnt = 0;
+	u32 state12, state17;
+
+	while (smlh_up == 0 || rdlh_up == 0 || ltssm_up == 0 ||
+	       speed_okay == 0) {
+		udelay(20);
+
+		state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12);
+		state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17);
+		smlh_up = IS_SMLH_LINK_UP(state12);
+		rdlh_up = IS_RDLH_LINK_UP(state12);
+		ltssm_up = IS_LTSSM_UP(state12);
+
+		if (PM_CURRENT_STATE(state17) < PCIE_GEN3)
+			speed_okay = 1;
+
+		if (smlh_up)
+			dev_dbg(dev, "smlh_link_up is on\n");
+		if (rdlh_up)
+			dev_dbg(dev, "rdlh_link_up is on\n");
+		if (ltssm_up)
+			dev_dbg(dev, "ltssm_up is on\n");
+		if (speed_okay)
+			dev_dbg(dev, "speed_okay\n");
+
+		cnt++;
+
+		if (cnt >= WAIT_LINKUP_TIMEOUT) {
+			dev_err(dev, "Error: Wait linkup timeout.\n");
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+static int meson_pcie_host_init(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct meson_pcie *mp = to_meson_pcie(pci);
+	int ret;
+
+	ret = meson_pcie_establish_link(mp);
+
+	if (ret)
+		return ret;
+
+	mp->device_attch = 1;
+	meson_pcie_enable_interrupts(mp);
+
+	return 0;
+}
+
+static const struct dw_pcie_host_ops meson_pcie_host_ops = {
+	.rd_own_conf = meson_pcie_rd_own_conf,
+	.wr_own_conf = meson_pcie_wr_own_conf,
+	.host_init = meson_pcie_host_init,
+};
+
+static int meson_add_pcie_port(struct meson_pcie *mp,
+			       struct platform_device *pdev)
+{
+	struct dw_pcie *pci = &mp->pci;
+	struct pcie_port *pp = &pci->pp;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		pp->msi_irq = platform_get_irq(pdev, 0);
+		if (pp->msi_irq < 0) {
+			dev_err(dev, "failed to get msi irq\n");
+			return pp->msi_irq;
+		}
+	}
+
+	pp->root_bus_nr = -1;
+	pp->ops = &meson_pcie_host_ops;
+	pci->dbi_base = mp->mem_res.elbi_base;
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(dev, "failed to initialize host\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.read_dbi = meson_pcie_read_dbi,
+	.write_dbi = meson_pcie_write_dbi,
+	.link_up = meson_pcie_link_up,
+};
+
+static int meson_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct dw_pcie *pci;
+	struct meson_pcie *mp;
+	struct meson_pcie_rc_reset *mrst;
+	int ret;
+
+	mp = devm_kzalloc(dev, sizeof(*mp), GFP_KERNEL);
+	if (!mp)
+		return -ENOMEM;
+
+	pci = &mp->pci;
+	pci->dev = dev;
+	pci->ops = &dw_pcie_ops;
+
+	mp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(mp->reset_gpio)) {
+		dev_err(dev, "Get reset gpio failed\n");
+		return PTR_ERR(mp->reset_gpio);
+	}
+
+	mp->phy = devm_of_phy_get(dev, np, NULL);
+	if (IS_ERR(mp->phy)) {
+		if (PTR_ERR(mp->phy) != -EPROBE_DEFER)
+			dev_err(dev, "Get phy failed, set default %ld\n",
+				PTR_ERR(mp->phy));
+		return PTR_ERR(mp->phy);
+	}
+
+	mrst = &mp->mrst;
+
+	mrst->port = devm_reset_control_get_shared(dev, "port");
+	if (IS_ERR(mrst->port)) {
+		if (PTR_ERR(mrst->port) != -EPROBE_DEFER)
+			dev_err(dev, "couldn't get port reset %ld\n",
+				PTR_ERR(mrst->port));
+
+		return PTR_ERR(mrst->port);
+	}
+
+	mrst->apb = devm_reset_control_get_shared(dev, "apb");
+	if (IS_ERR(mrst->apb)) {
+		if (PTR_ERR(mrst->apb) != -EPROBE_DEFER)
+			dev_err(dev, "couldn't get apb reset\n");
+
+		return PTR_ERR(mrst->apb);
+	}
+
+	reset_control_deassert(mrst->port);
+	reset_control_deassert(mrst->apb);
+
+	phy_power_on(mp->phy);
+
+	ret = meson_pcie_init_clk(mp);
+	if (ret) {
+		dev_err(dev, "Init clock resources failed, %d\n", ret);
+		return ret;
+	}
+
+	ret = meson_pcie_get_mem(pdev, mp);
+	if (ret) {
+		dev_err(dev, "Get memory resource failed, %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, mp);
+
+	ret = meson_add_pcie_port(mp, pdev);
+	if (ret < 0) {
+		dev_err(dev, "Add PCIE port failed, %d\n", ret);
+		meson_pcie_deinit_clk(mp);
+	}
+
+	return ret;
+}
+
+static const struct of_device_id meson_pcie_of_match[] = {
+	{
+		.compatible = "amlogic,axg-pcie",
+	},
+	{},
+};
+
+static struct platform_driver meson_pcie_driver = {
+	.probe = meson_pcie_probe,
+	.driver = {
+		.name = "meson-pcie",
+		.of_match_table = meson_pcie_of_match,
+	},
+};
+
+builtin_platform_driver(meson_pcie_driver);
-- 
2.7.4

[PATCH v2 2/2] PCI: meson: add the Amlogic Meson PCIe controller driver

[Jerome Brunet]

On Fri, 2018-08-24 at 15:36 +0800, Hanjie Lin wrote:
> From: Yue Wang <yue.wang@amlogic.com>
> 
> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
> PCI core. This patch adds the driver support for Meson PCIe controller.
> 
> Signed-off-by: Yue Wang <yue.wang@amlogic.com>
> Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
> ---
>  drivers/pci/controller/dwc/Kconfig     |  12 +
>  drivers/pci/controller/dwc/Makefile    |   1 +
>  drivers/pci/controller/dwc/pci-meson.c | 613 +++++++++++++++++++++++++++++++++
>  3 files changed, 626 insertions(+)
>  create mode 100644 drivers/pci/controller/dwc/pci-meson.c
> 
> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> index 91b0194..6cb36f6 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -193,4 +193,16 @@ config PCIE_HISI_STB
>  	help
>            Say Y here if you want PCIe controller support on HiSilicon STB SoCs
>  
> +config PCI_MESON
> +	bool "MESON PCIe controller"
> +	depends on PCI
> +	depends on PCI_MSI_IRQ_DOMAIN
> +	select PCIEPORTBUS
> +	select PCIE_DW_HOST
> +	help
> +	  Say Y here if you want to enable PCI controller support on Amlogic
> +	  SoCs. The PCI controller on Amlogic is based on DesignWare hardware
> +	  and therefore the driver re-uses the DesignWare core functions to
> +	  implement the driver.
> +
>  endmenu
> diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
> index 5d2ce72..cf676bd 100644
> --- a/drivers/pci/controller/dwc/Makefile
> +++ b/drivers/pci/controller/dwc/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
>  obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
>  obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o
>  obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
> +obj-$(CONFIG_PCI_MESON) += pci-meson.o
>  
>  # The following drivers are for devices that use the generic ACPI
>  # pci_root.c driver but don't support standard ECAM config access.
> diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c
> new file mode 100644
> index 0000000..a9edf20
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pci-meson.c
> @@ -0,0 +1,613 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * PCIe host controller driver for Amlogic MESON SoCs
> + *
> + * Copyright (c) 2018 Amlogic, inc.
> + * Author: Yue Wang <yue.wang@amlogic.com>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/of_device.h>
> +#include <linux/of_gpio.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/phy/phy.h>
> +#include <linux/resource.h>
> +#include <linux/types.h>
> +#include <linux/reset.h>
> +
> +#include "pcie-designware.h"
> +
> +#define to_meson_pcie(x) dev_get_drvdata((x)->dev)
> +
> +/* External local bus interface registers */
> +#define PLR_OFFSET			0x700
> +#define PCIE_PORT_LINK_CTRL_OFF		(PLR_OFFSET + 0x10)
> +#define FAST_LINK_MODE			BIT(7)
> +#define LINK_CAPABLE_MASK		GENMASK(21, 16)
> +#define LINK_CAPABLE_X1			BIT(16)
> +
> +#define PCIE_GEN2_CTRL_OFF		(PLR_OFFSET + 0x10c)
> +#define NUM_OF_LANES_MASK		GENMASK(12, 8)
> +#define NUM_OF_LANES_X1			BIT(8)
> +#define DIRECT_SPEED_CHANGE		BIT(17)
> +
> +#define TYPE1_HDR_OFFSET		0x0
> +#define PCIE_STATUS_COMMAND		(TYPE1_HDR_OFFSET + 0x04)
> +#define PCI_IO_EN			BIT(0)
> +#define PCI_MEM_SPACE_EN		BIT(1)
> +#define PCI_BUS_MASTER_EN		BIT(2)
> +
> +#define PCIE_BASE_ADDR0			(TYPE1_HDR_OFFSET + 0x10)
> +#define PCIE_BASE_ADDR1			(TYPE1_HDR_OFFSET + 0x14)
> +
> +#define PCIE_CAP_OFFSET			0x70
> +#define PCIE_DEV_CTRL_DEV_STUS		(PCIE_CAP_OFFSET + 0x08)
> +#define PCIE_CAP_MAX_PAYLOAD_MASK	GENMASK(7, 5)
> +#define PCIE_CAP_MAX_PAYLOAD_SIZE(x)	((x) << 5)
> +#define PCIE_CAP_MAX_READ_REQ_MASK	GENMASK(14, 12)
> +#define PCIE_CAP_MAX_READ_REQ_SIZE(x)	((x) << 12)
> +
> +#define PCI_CLASS_REVISION_MASK		GENMASK(7, 0)
> +
> +/* PCIe specific config registers */
> +#define PCIE_CFG0			0x0
> +#define APP_LTSSM_ENABLE		BIT(7)
> +
> +#define PCIE_CFG_STATUS12		0x30
> +#define IS_SMLH_LINK_UP(x)		((x) & (1 << 6))
> +#define IS_RDLH_LINK_UP(x)		((x) & (1 << 16))
> +#define IS_LTSSM_UP(x)			((((x) >> 10) & 0x1f) == 0x11)
> +
> +#define PCIE_CFG_STATUS17		0x44
> +#define PM_CURRENT_STATE(x)		(((x) >> 7) & 0x1)
> +
> +#define WAIT_LINKUP_TIMEOUT		2000
> +#define PORT_CLK_RATE			100000000UL
> +#define MAX_PAYLOAD_SIZE		256
> +#define MAX_READ_REQ_SIZE		256
> +
> +enum pcie_data_rate {
> +	PCIE_GEN1,
> +	PCIE_GEN2,
> +	PCIE_GEN3,
> +	PCIE_GEN4
> +};
> +
> +struct meson_pcie_mem_res {
> +	void __iomem *elbi_base; /* DT 0th resource */
> +	void __iomem *cfg_base; /* DT 2nd resource */
> +};
> +
> +struct meson_pcie_clk_res {
> +	struct clk *clk;
> +	struct clk *mipi_gate;
> +	struct clk *port_clk;
> +	struct clk *general_clk;
> +};
> +
> +struct meson_pcie_rc_reset {
> +	struct reset_control *port;
> +	struct reset_control *apb;
> +};
> +
> +struct meson_pcie {
> +	struct dw_pcie pci;
> +	struct meson_pcie_mem_res mem_res;
> +	struct meson_pcie_clk_res clk_res;
> +	struct meson_pcie_rc_reset mrst;
> +	struct gpio_desc *reset_gpio;
> +
> +	struct phy *phy;
> +	enum of_gpio_flags gpio_flag;
> +	int pcie_num;
> +	u32 port_num;
> +	u32 device_attch;
> +};
> +
> +static int meson_pcie_get_mem(struct platform_device *pdev,
> +			      struct meson_pcie *mp)
> +{
> +	struct device *dev = mp->pci.dev;
> +	struct resource *res;
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
> +	if (!res)
> +		return -ENODEV;
> +
> +	mp->mem_res.elbi_base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(mp->mem_res.elbi_base))
> +		return PTR_ERR(mp->mem_res.elbi_base);
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
> +	if (!res)
> +		return -ENODEV;
> +
> +	mp->mem_res.cfg_base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(mp->mem_res.cfg_base))
> +		return PTR_ERR(mp->mem_res.cfg_base);
> +
> +	return 0;
> +}
> +
> +static void meson_pcie_rc_reset(struct meson_pcie *mp)
> +{
> +	struct meson_pcie_rc_reset *mrst = &mp->mrst;
> +
> +	reset_control_assert(mrst->port);
> +	reset_control_assert(mrst->apb);
> +	udelay(400);
> +	reset_control_deassert(mrst->port);
> +	reset_control_deassert(mrst->apb);
> +	udelay(500);
> +}
> +
> +static int meson_pcie_init_clk(struct meson_pcie *mp)
> +{
> +	struct device *dev = mp->pci.dev;
> +	struct meson_pcie_clk_res *res = &mp->clk_res;
> +	int ret;
> +
> +	res->port_clk = devm_clk_get(dev, "port");
> +	if (IS_ERR(res->port_clk)) {
> +		if (PTR_ERR(res->port_clk) != -EPROBE_DEFER)
> +			dev_err(dev, "Failed to get pcie port clock\n");
> +
> +		return PTR_ERR(res->port_clk);
> +	}
> +
> +	res->mipi_gate = devm_clk_get(dev, "pcie_mipi_en");
> +	if (IS_ERR(res->mipi_gate)) {
> +		if (PTR_ERR(res->mipi_gate) != -EPROBE_DEFER)
> +			dev_err(dev, "Failed to get pcie mipi clock\n");
> +
> +		return PTR_ERR(res->mipi_gate);
> +	}
> +
> +	res->general_clk = devm_clk_get(dev, "pcie_general");
> +	if (IS_ERR(res->general_clk)) {
> +		if (PTR_ERR(res->general_clk) != -EPROBE_DEFER)
> +			dev_err(dev, "Failed to get pcie general clock\n");
> +
> +		return PTR_ERR(res->general_clk);
> +	}
> +
> +	res->clk = devm_clk_get(dev, "pcie");
> +	if (IS_ERR(res->clk)) {
> +		if (PTR_ERR(res->clk) != -EPROBE_DEFER)
> +			dev_err(dev, "Failed to get pcie rc clock\n");
> +
> +		return PTR_ERR(res->clk);
> +	}
> +
> +	phy_init(mp->phy);
> +	meson_pcie_rc_reset(mp);
> +
> +	ret = clk_set_rate(res->port_clk, PORT_CLK_RATE);
> +	if (ret) {
> +		dev_err(dev, "set bus clk rate failed, ret = %d", ret);
> +		goto err_clk;
> +	}
> +
> +	ret = clk_prepare_enable(res->port_clk);
> +	if (ret) {
> +		dev_err(dev, "cannot enable pcie port clock");
> +		goto err_clk;
> +	}
> +
> +	ret = clk_prepare_enable(res->mipi_gate);
> +	if (ret) {
> +		dev_err(dev, "cannot enable pcie mipi gate clock");
> +		goto err_port_clk;
> +	}
> +
> +	ret = clk_prepare_enable(res->general_clk);
> +	if (ret) {
> +		dev_err(dev, "cannot enable pcie general clock");
> +		goto err_mipi_gate;
> +	}
> +
> +	ret = clk_prepare_enable(res->clk);
> +	if (ret) {
> +		dev_err(dev, "cannot enable pcie rc clock");
> +		goto err_general_clk;
> +	}
> +
> +	return 0;
> +
> +err_general_clk:
> +	clk_disable_unprepare(res->general_clk);
> +err_mipi_gate:
> +	clk_disable_unprepare(res->mipi_gate);
> +err_port_clk:
> +	clk_disable_unprepare(res->port_clk);
> +err_clk:
> +	return ret;

You are doing this from device probe but there is no remove counter part,
meaning the clock will be left enabled when the device is removed (and clock
count unbalanced). To just fire and forget clock, like you are doing, you could
use :

devm_add_action_or_reset(dev, (void(*)(void *))clk_disable_unprepare,
				<you-clk>);

This will take care of the errors cases and driver removal
Maybe you could make an helper function to do the get - enable - add reset.
Also, if the you just fire and forget the clock in this way, you don't need to
keep the clock pointer around (in your device data)

Last, do you really need to enable all the clocks at probe time ? Can't some be
enabled later on. I don't know much about pcie but maybe some enable could be
delayed until the pcie bus is actually connected to something ? in use ?

> +}
> +
> +static void meson_pcie_deinit_clk(struct meson_pcie *mp)
> +{
> +	clk_disable_unprepare(mp->clk_res.clk);
> +	clk_disable_unprepare(mp->clk_res.general_clk);
> +	clk_disable_unprepare(mp->clk_res.mipi_gate);
> +	clk_disable_unprepare(mp->clk_res.port_clk);
> +}

... then you can remove this function

> +
> +static inline void meson_elb_writel(struct meson_pcie *mp, u32 val, u32 reg)
> +{
> +	writel(val, mp->mem_res.elbi_base + reg);
> +}
> +
> +static inline u32 meson_elb_readl(struct meson_pcie *mp, u32 reg)
> +{
> +	return readl(mp->mem_res.elbi_base + reg);
> +}
> +
> +static inline u32 meson_cfg_readl(struct meson_pcie *mp, u32 reg)
> +{
> +	return readl(mp->mem_res.cfg_base + reg);
> +}
> +
> +static inline void meson_cfg_writel(struct meson_pcie *mp, u32 val, u32 reg)
> +{
> +	writel(val, mp->mem_res.cfg_base + reg);
> +}
> +
> +static void meson_pcie_assert_reset(struct meson_pcie *mp)
> +{
> +	gpiod_set_value_cansleep(mp->reset_gpio, 0);
> +	udelay(500);
> +	gpiod_set_value_cansleep(mp->reset_gpio, 1);
> +}
> +
> +static void meson_pcie_init_dw(struct meson_pcie *mp)
> +{
> +	u32 val = 0;
> +
> +	val = meson_cfg_readl(mp, PCIE_CFG0);
> +	val |= APP_LTSSM_ENABLE;
> +	meson_cfg_writel(mp, val, PCIE_CFG0);
> +
> +	val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF);
> +	val &= ~LINK_CAPABLE_MASK;
> +	meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
> +
> +	val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF);
> +	val |= LINK_CAPABLE_X1 | FAST_LINK_MODE;
> +	meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
> +
> +	val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);
> +	val &= ~NUM_OF_LANES_MASK;
> +	meson_elb_writel(mp, val, PCIE_GEN2_CTRL_OFF);
> +
> +	val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);
> +	val |= NUM_OF_LANES_X1 | DIRECT_SPEED_CHANGE;
> +	meson_elb_writel(mp, val, PCIE_GEN2_CTRL_OFF);
> +
> +	meson_elb_writel(mp, 0x0, PCIE_BASE_ADDR0);
> +	meson_elb_writel(mp, 0x0, PCIE_BASE_ADDR1);
> +}
> +
> +static int meson_size_to_payload(int size)
> +{
> +	if (size & (size - 1) || size < 128 || size > 4096)
> +		return 1;
> +
> +	return fls(size) - 8;
> +}
> +
> +static void meson_set_max_payload(struct meson_pcie *mp, int size)
> +{
> +	u32 val = 0;
> +	int max_payload_size = meson_size_to_payload(size);
> +
> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
> +	val &= ~PCIE_CAP_MAX_PAYLOAD_MASK;
> +	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
> +
> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
> +	val |= PCIE_CAP_MAX_PAYLOAD_SIZE(max_payload_size);
> +	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
> +}
> +
> +static void meson_set_max_rd_req_size(struct meson_pcie *mp, int size)
> +{
> +	u32 val = 0;
> +	int max_rd_req_size = meson_size_to_payload(size);
> +
> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
> +	val &= ~PCIE_CAP_MAX_READ_REQ_MASK;
> +	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
> +
> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
> +	val |= PCIE_CAP_MAX_READ_REQ_SIZE(max_rd_req_size);
> +	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
> +}
> +
> +static inline void meson_enable_memory_space(struct meson_pcie *mp)
> +{
> +	/* Set the RC Bus Master, Memory Space and I/O Space enables */
> +	meson_elb_writel(mp, PCI_IO_EN | PCI_MEM_SPACE_EN | PCI_BUS_MASTER_EN,
> +			 PCIE_STATUS_COMMAND);
> +}
> +
> +static int meson_pcie_establish_link(struct meson_pcie *mp)
> +{
> +	struct dw_pcie *pci = &mp->pci;
> +	struct pcie_port *pp = &pci->pp;
> +
> +	meson_pcie_init_dw(mp);
> +	meson_set_max_payload(mp, MAX_PAYLOAD_SIZE);
> +	meson_set_max_rd_req_size(mp, MAX_READ_REQ_SIZE);
> +
> +	dw_pcie_setup_rc(pp);
> +	meson_enable_memory_space(mp);
> +
> +	meson_pcie_assert_reset(mp);
> +
> +	/* check if the link is up or not */
> +	if (!dw_pcie_wait_for_link(pci))
> +		return 0;
> +
> +	return -ETIMEDOUT;
> +}
> +
> +static void meson_pcie_msi_init(struct meson_pcie *mp)
> +{
> +	struct pcie_port *pp = &mp->pci.pp;
> +
> +	dw_pcie_msi_init(pp);
> +}
> +
> +static void meson_pcie_enable_interrupts(struct meson_pcie *mp)
> +{
> +	if (IS_ENABLED(CONFIG_PCI_MSI))
> +		meson_pcie_msi_init(mp);
> +}
> +
> +static u32 meson_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base,
> +			       u32 reg, size_t size)
> +{
> +	u32 val;
> +
> +	dw_pcie_read(base + reg, size, &val);
> +
> +	return val;
> +}
> +
> +static void meson_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base,
> +				 u32 reg, size_t size, u32 val)
> +{
> +	dw_pcie_write(base + reg, size, val);
> +}
> +
> +static int meson_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
> +				  u32 *val)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct meson_pcie *mp = to_meson_pcie(pci);
> +
> +	if (!mp->device_attch)
> +		return 0;
> +
> +	/* the device class is not reported correctly from the register */
> +	if (where == PCI_CLASS_REVISION) {
> +		*val = readl(pci->dbi_base + PCI_CLASS_REVISION);
> +		/* keep revision id */
> +		*val &= PCI_CLASS_REVISION_MASK;
> +		*val |= PCI_CLASS_BRIDGE_PCI << 16;
> +		return PCIBIOS_SUCCESSFUL;
> +	}
> +
> +	return dw_pcie_read(pci->dbi_base + where, size, val);
> +}
> +
> +static int meson_pcie_wr_own_conf(struct pcie_port *pp, int where,
> +				  int size, u32 val)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct meson_pcie *mp = to_meson_pcie(pci);
> +
> +	if (!mp->device_attch)
> +		return 0;
> +
> +	return dw_pcie_write(pci->dbi_base + where, size, val);
> +}
> +
> +static int meson_pcie_link_up(struct dw_pcie *pci)
> +{
> +	struct meson_pcie *mp = to_meson_pcie(pci);
> +	struct device *dev = pci->dev;
> +	u32 smlh_up = 0;
> +	u32 ltssm_up = 0;
> +	u32 rdlh_up = 0;
> +	u32 speed_okay = 0;
> +	u32 cnt = 0;
> +	u32 state12, state17;
> +
> +	while (smlh_up == 0 || rdlh_up == 0 || ltssm_up == 0 ||
> +	       speed_okay == 0) {
> +		udelay(20);
> +
> +		state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12);
> +		state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17);
> +		smlh_up = IS_SMLH_LINK_UP(state12);
> +		rdlh_up = IS_RDLH_LINK_UP(state12);
> +		ltssm_up = IS_LTSSM_UP(state12);
> +
> +		if (PM_CURRENT_STATE(state17) < PCIE_GEN3)
> +			speed_okay = 1;
> +
> +		if (smlh_up)
> +			dev_dbg(dev, "smlh_link_up is on\n");
> +		if (rdlh_up)
> +			dev_dbg(dev, "rdlh_link_up is on\n");
> +		if (ltssm_up)
> +			dev_dbg(dev, "ltssm_up is on\n");
> +		if (speed_okay)
> +			dev_dbg(dev, "speed_okay\n");
> +
> +		cnt++;
> +
> +		if (cnt >= WAIT_LINKUP_TIMEOUT) {
> +			dev_err(dev, "Error: Wait linkup timeout.\n");
> +			return 0;
> +		}
> +	}
> +
> +	return 1;
> +}
> +
> +static int meson_pcie_host_init(struct pcie_port *pp)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct meson_pcie *mp = to_meson_pcie(pci);
> +	int ret;
> +
> +	ret = meson_pcie_establish_link(mp);
> +
> +	if (ret)
> +		return ret;
> +
> +	mp->device_attch = 1;
> +	meson_pcie_enable_interrupts(mp);
> +
> +	return 0;
> +}
> +
> +static const struct dw_pcie_host_ops meson_pcie_host_ops = {
> +	.rd_own_conf = meson_pcie_rd_own_conf,
> +	.wr_own_conf = meson_pcie_wr_own_conf,
> +	.host_init = meson_pcie_host_init,
> +};
> +
> +static int meson_add_pcie_port(struct meson_pcie *mp,
> +			       struct platform_device *pdev)
> +{
> +	struct dw_pcie *pci = &mp->pci;
> +	struct pcie_port *pp = &pci->pp;
> +	struct device *dev = &pdev->dev;
> +	int ret;
> +
> +	if (IS_ENABLED(CONFIG_PCI_MSI)) {
> +		pp->msi_irq = platform_get_irq(pdev, 0);
> +		if (pp->msi_irq < 0) {
> +			dev_err(dev, "failed to get msi irq\n");
> +			return pp->msi_irq;
> +		}
> +	}
> +
> +	pp->root_bus_nr = -1;
> +	pp->ops = &meson_pcie_host_ops;
> +	pci->dbi_base = mp->mem_res.elbi_base;
> +
> +	ret = dw_pcie_host_init(pp);
> +	if (ret) {
> +		dev_err(dev, "failed to initialize host\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct dw_pcie_ops dw_pcie_ops = {
> +	.read_dbi = meson_pcie_read_dbi,
> +	.write_dbi = meson_pcie_write_dbi,
> +	.link_up = meson_pcie_link_up,
> +};
> +
> +static int meson_pcie_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct dw_pcie *pci;
> +	struct meson_pcie *mp;
> +	struct meson_pcie_rc_reset *mrst;
> +	int ret;
> +
> +	mp = devm_kzalloc(dev, sizeof(*mp), GFP_KERNEL);
> +	if (!mp)
> +		return -ENOMEM;
> +
> +	pci = &mp->pci;
> +	pci->dev = dev;
> +	pci->ops = &dw_pcie_ops;
> +
> +	mp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(mp->reset_gpio)) {
> +		dev_err(dev, "Get reset gpio failed\n");
> +		return PTR_ERR(mp->reset_gpio);
> +	}
> +
> +	mp->phy = devm_of_phy_get(dev, np, NULL);

For the 3rd time, you do *not* need a phy driver to just handle a reset line.
It is overkill.

you should claim the shared reset line here and be done with it.

> +	if (IS_ERR(mp->phy)) {
> +		if (PTR_ERR(mp->phy) != -EPROBE_DEFER)
> +			dev_err(dev, "Get phy failed, set default %ld\n",
> +				PTR_ERR(mp->phy));
> +		return PTR_ERR(mp->phy);
> +	}
> +
> +	mrst = &mp->mrst;
> +
> +	mrst->port = devm_reset_control_get_shared(dev, "port");

There is no reason for this reset to be shared since there is one per pcie port.

> +	if (IS_ERR(mrst->port)) {
> +		if (PTR_ERR(mrst->port) != -EPROBE_DEFER)
> +			dev_err(dev, "couldn't get port reset %ld\n",
> +				PTR_ERR(mrst->port));
> +
> +		return PTR_ERR(mrst->port);
> +	}
> +
> +	mrst->apb = devm_reset_control_get_shared(dev, "apb");
> +	if (IS_ERR(mrst->apb)) {
> +		if (PTR_ERR(mrst->apb) != -EPROBE_DEFER)
> +			dev_err(dev, "couldn't get apb reset\n");
> +
> +		return PTR_ERR(mrst->apb);
> +	}
> +
> +	reset_control_deassert(mrst->port);
> +	reset_control_deassert(mrst->apb);
> +
> +	phy_power_on(mp->phy);
> +
> +	ret = meson_pcie_init_clk(mp);
> +	if (ret) {
> +		dev_err(dev, "Init clock resources failed, %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = meson_pcie_get_mem(pdev, mp);
> +	if (ret) {
> +		dev_err(dev, "Get memory resource failed, %d\n", ret);
> +		return ret;
> +	}
> +
> +	platform_set_drvdata(pdev, mp);
> +
> +	ret = meson_add_pcie_port(mp, pdev);
> +	if (ret < 0) {
> +		dev_err(dev, "Add PCIE port failed, %d\n", ret);
> +		meson_pcie_deinit_clk(mp);
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct of_device_id meson_pcie_of_match[] = {
> +	{
> +		.compatible = "amlogic,axg-pcie",
> +	},
> +	{},
> +};
> +
> +static struct platform_driver meson_pcie_driver = {
> +	.probe = meson_pcie_probe,
> +	.driver = {
> +		.name = "meson-pcie",
> +		.of_match_table = meson_pcie_of_match,
> +	},
> +};
> +
> +builtin_platform_driver(meson_pcie_driver);

[PATCH v2 2/2] PCI: meson: add the Amlogic Meson PCIe controller driver

[Hanjie Lin]

On 2018/8/24 16:22, Jerome Brunet wrote:
> On Fri, 2018-08-24 at 15:36 +0800, Hanjie Lin wrote:
>> From: Yue Wang <yue.wang@amlogic.com>
>>
>> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
>> PCI core. This patch adds the driver support for Meson PCIe controller.
>>
>> Signed-off-by: Yue Wang <yue.wang@amlogic.com>
>> Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
>> ---
>>  drivers/pci/controller/dwc/Kconfig     |  12 +
>>  drivers/pci/controller/dwc/Makefile    |   1 +
>>  drivers/pci/controller/dwc/pci-meson.c | 613 +++++++++++++++++++++++++++++++++
>>  3 files changed, 626 insertions(+)
>>  create mode 100644 drivers/pci/controller/dwc/pci-meson.c
>>
>> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
>> index 91b0194..6cb36f6 100644
>> --- a/drivers/pci/controller/dwc/Kconfig
>> +++ b/drivers/pci/controller/dwc/Kconfig
>> @@ -193,4 +193,16 @@ config PCIE_HISI_STB
>>  	help
>>            Say Y here if you want PCIe controller support on HiSilicon STB SoCs
>>  
>> +config PCI_MESON
>> +	bool "MESON PCIe controller"
>> +	depends on PCI
>> +	depends on PCI_MSI_IRQ_DOMAIN
>> +	select PCIEPORTBUS
>> +	select PCIE_DW_HOST
>> +	help
>> +	  Say Y here if you want to enable PCI controller support on Amlogic
>> +	  SoCs. The PCI controller on Amlogic is based on DesignWare hardware
>> +	  and therefore the driver re-uses the DesignWare core functions to
>> +	  implement the driver.
>> +
>>  endmenu
>> diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
>> index 5d2ce72..cf676bd 100644
>> --- a/drivers/pci/controller/dwc/Makefile
>> +++ b/drivers/pci/controller/dwc/Makefile
>> @@ -14,6 +14,7 @@ obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
>>  obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
>>  obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o
>>  obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
>> +obj-$(CONFIG_PCI_MESON) += pci-meson.o
>>  
>>  # The following drivers are for devices that use the generic ACPI
>>  # pci_root.c driver but don't support standard ECAM config access.
>> diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c
>> new file mode 100644
>> index 0000000..a9edf20
>> --- /dev/null
>> +++ b/drivers/pci/controller/dwc/pci-meson.c
>> @@ -0,0 +1,613 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * PCIe host controller driver for Amlogic MESON SoCs
>> + *
>> + * Copyright (c) 2018 Amlogic, inc.
>> + * Author: Yue Wang <yue.wang@amlogic.com>
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/delay.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/pci.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/phy/phy.h>
>> +#include <linux/resource.h>
>> +#include <linux/types.h>
>> +#include <linux/reset.h>
>> +
>> +#include "pcie-designware.h"
>> +
>> +#define to_meson_pcie(x) dev_get_drvdata((x)->dev)
>> +
>> +/* External local bus interface registers */
>> +#define PLR_OFFSET			0x700
>> +#define PCIE_PORT_LINK_CTRL_OFF		(PLR_OFFSET + 0x10)
>> +#define FAST_LINK_MODE			BIT(7)
>> +#define LINK_CAPABLE_MASK		GENMASK(21, 16)
>> +#define LINK_CAPABLE_X1			BIT(16)
>> +
>> +#define PCIE_GEN2_CTRL_OFF		(PLR_OFFSET + 0x10c)
>> +#define NUM_OF_LANES_MASK		GENMASK(12, 8)
>> +#define NUM_OF_LANES_X1			BIT(8)
>> +#define DIRECT_SPEED_CHANGE		BIT(17)
>> +
>> +#define TYPE1_HDR_OFFSET		0x0
>> +#define PCIE_STATUS_COMMAND		(TYPE1_HDR_OFFSET + 0x04)
>> +#define PCI_IO_EN			BIT(0)
>> +#define PCI_MEM_SPACE_EN		BIT(1)
>> +#define PCI_BUS_MASTER_EN		BIT(2)
>> +
>> +#define PCIE_BASE_ADDR0			(TYPE1_HDR_OFFSET + 0x10)
>> +#define PCIE_BASE_ADDR1			(TYPE1_HDR_OFFSET + 0x14)
>> +
>> +#define PCIE_CAP_OFFSET			0x70
>> +#define PCIE_DEV_CTRL_DEV_STUS		(PCIE_CAP_OFFSET + 0x08)
>> +#define PCIE_CAP_MAX_PAYLOAD_MASK	GENMASK(7, 5)
>> +#define PCIE_CAP_MAX_PAYLOAD_SIZE(x)	((x) << 5)
>> +#define PCIE_CAP_MAX_READ_REQ_MASK	GENMASK(14, 12)
>> +#define PCIE_CAP_MAX_READ_REQ_SIZE(x)	((x) << 12)
>> +
>> +#define PCI_CLASS_REVISION_MASK		GENMASK(7, 0)
>> +
>> +/* PCIe specific config registers */
>> +#define PCIE_CFG0			0x0
>> +#define APP_LTSSM_ENABLE		BIT(7)
>> +
>> +#define PCIE_CFG_STATUS12		0x30
>> +#define IS_SMLH_LINK_UP(x)		((x) & (1 << 6))
>> +#define IS_RDLH_LINK_UP(x)		((x) & (1 << 16))
>> +#define IS_LTSSM_UP(x)			((((x) >> 10) & 0x1f) == 0x11)
>> +
>> +#define PCIE_CFG_STATUS17		0x44
>> +#define PM_CURRENT_STATE(x)		(((x) >> 7) & 0x1)
>> +
>> +#define WAIT_LINKUP_TIMEOUT		2000
>> +#define PORT_CLK_RATE			100000000UL
>> +#define MAX_PAYLOAD_SIZE		256
>> +#define MAX_READ_REQ_SIZE		256
>> +
>> +enum pcie_data_rate {
>> +	PCIE_GEN1,
>> +	PCIE_GEN2,
>> +	PCIE_GEN3,
>> +	PCIE_GEN4
>> +};
>> +
>> +struct meson_pcie_mem_res {
>> +	void __iomem *elbi_base; /* DT 0th resource */
>> +	void __iomem *cfg_base; /* DT 2nd resource */
>> +};
>> +
>> +struct meson_pcie_clk_res {
>> +	struct clk *clk;
>> +	struct clk *mipi_gate;
>> +	struct clk *port_clk;
>> +	struct clk *general_clk;
>> +};
>> +
>> +struct meson_pcie_rc_reset {
>> +	struct reset_control *port;
>> +	struct reset_control *apb;
>> +};
>> +
>> +struct meson_pcie {
>> +	struct dw_pcie pci;
>> +	struct meson_pcie_mem_res mem_res;
>> +	struct meson_pcie_clk_res clk_res;
>> +	struct meson_pcie_rc_reset mrst;
>> +	struct gpio_desc *reset_gpio;
>> +
>> +	struct phy *phy;
>> +	enum of_gpio_flags gpio_flag;
>> +	int pcie_num;
>> +	u32 port_num;
>> +	u32 device_attch;
>> +};
>> +
>> +static int meson_pcie_get_mem(struct platform_device *pdev,
>> +			      struct meson_pcie *mp)
>> +{
>> +	struct device *dev = mp->pci.dev;
>> +	struct resource *res;
>> +
>> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
>> +	if (!res)
>> +		return -ENODEV;
>> +
>> +	mp->mem_res.elbi_base = devm_ioremap_resource(dev, res);
>> +	if (IS_ERR(mp->mem_res.elbi_base))
>> +		return PTR_ERR(mp->mem_res.elbi_base);
>> +
>> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
>> +	if (!res)
>> +		return -ENODEV;
>> +
>> +	mp->mem_res.cfg_base = devm_ioremap_resource(dev, res);
>> +	if (IS_ERR(mp->mem_res.cfg_base))
>> +		return PTR_ERR(mp->mem_res.cfg_base);
>> +
>> +	return 0;
>> +}
>> +
>> +static void meson_pcie_rc_reset(struct meson_pcie *mp)
>> +{
>> +	struct meson_pcie_rc_reset *mrst = &mp->mrst;
>> +
>> +	reset_control_assert(mrst->port);
>> +	reset_control_assert(mrst->apb);
>> +	udelay(400);
>> +	reset_control_deassert(mrst->port);
>> +	reset_control_deassert(mrst->apb);
>> +	udelay(500);
>> +}
>> +
>> +static int meson_pcie_init_clk(struct meson_pcie *mp)
>> +{
>> +	struct device *dev = mp->pci.dev;
>> +	struct meson_pcie_clk_res *res = &mp->clk_res;
>> +	int ret;
>> +
>> +	res->port_clk = devm_clk_get(dev, "port");
>> +	if (IS_ERR(res->port_clk)) {
>> +		if (PTR_ERR(res->port_clk) != -EPROBE_DEFER)
>> +			dev_err(dev, "Failed to get pcie port clock\n");
>> +
>> +		return PTR_ERR(res->port_clk);
>> +	}
>> +
>> +	res->mipi_gate = devm_clk_get(dev, "pcie_mipi_en");
>> +	if (IS_ERR(res->mipi_gate)) {
>> +		if (PTR_ERR(res->mipi_gate) != -EPROBE_DEFER)
>> +			dev_err(dev, "Failed to get pcie mipi clock\n");
>> +
>> +		return PTR_ERR(res->mipi_gate);
>> +	}
>> +
>> +	res->general_clk = devm_clk_get(dev, "pcie_general");
>> +	if (IS_ERR(res->general_clk)) {
>> +		if (PTR_ERR(res->general_clk) != -EPROBE_DEFER)
>> +			dev_err(dev, "Failed to get pcie general clock\n");
>> +
>> +		return PTR_ERR(res->general_clk);
>> +	}
>> +
>> +	res->clk = devm_clk_get(dev, "pcie");
>> +	if (IS_ERR(res->clk)) {
>> +		if (PTR_ERR(res->clk) != -EPROBE_DEFER)
>> +			dev_err(dev, "Failed to get pcie rc clock\n");
>> +
>> +		return PTR_ERR(res->clk);
>> +	}
>> +
>> +	phy_init(mp->phy);
>> +	meson_pcie_rc_reset(mp);
>> +
>> +	ret = clk_set_rate(res->port_clk, PORT_CLK_RATE);
>> +	if (ret) {
>> +		dev_err(dev, "set bus clk rate failed, ret = %d", ret);
>> +		goto err_clk;
>> +	}
>> +
>> +	ret = clk_prepare_enable(res->port_clk);
>> +	if (ret) {
>> +		dev_err(dev, "cannot enable pcie port clock");
>> +		goto err_clk;
>> +	}
>> +
>> +	ret = clk_prepare_enable(res->mipi_gate);
>> +	if (ret) {
>> +		dev_err(dev, "cannot enable pcie mipi gate clock");
>> +		goto err_port_clk;
>> +	}
>> +
>> +	ret = clk_prepare_enable(res->general_clk);
>> +	if (ret) {
>> +		dev_err(dev, "cannot enable pcie general clock");
>> +		goto err_mipi_gate;
>> +	}
>> +
>> +	ret = clk_prepare_enable(res->clk);
>> +	if (ret) {
>> +		dev_err(dev, "cannot enable pcie rc clock");
>> +		goto err_general_clk;
>> +	}
>> +
>> +	return 0;
>> +
>> +err_general_clk:
>> +	clk_disable_unprepare(res->general_clk);
>> +err_mipi_gate:
>> +	clk_disable_unprepare(res->mipi_gate);
>> +err_port_clk:
>> +	clk_disable_unprepare(res->port_clk);
>> +err_clk:
>> +	return ret;
> 
> You are doing this from device probe but there is no remove counter part,
> meaning the clock will be left enabled when the device is removed (and clock
> count unbalanced). To just fire and forget clock, like you are doing, you could
> use :
> 
> devm_add_action_or_reset(dev, (void(*)(void *))clk_disable_unprepare,
> 				<you-clk>);
> 
> This will take care of the errors cases and driver removal
> Maybe you could make an helper function to do the get - enable - add reset.
> Also, if the you just fire and forget the clock in this way, you don't need to
> keep the clock pointer around (in your device data)
> 
> Last, do you really need to enable all the clocks at probe time ? Can't some be
> enabled later on. I don't know much about pcie but maybe some enable could be
> delayed until the pcie bus is actually connected to something ? in use ?
> 

Yes, it's better to use devm_add_action_or_reset().

Amlogic pcie driver doesn't support hotplug, so we must enable all clocks
during system initialization.

>> +}
>> +
>> +static void meson_pcie_deinit_clk(struct meson_pcie *mp)
>> +{
>> +	clk_disable_unprepare(mp->clk_res.clk);
>> +	clk_disable_unprepare(mp->clk_res.general_clk);
>> +	clk_disable_unprepare(mp->clk_res.mipi_gate);
>> +	clk_disable_unprepare(mp->clk_res.port_clk);
>> +}
> 
> ... then you can remove this function

Ok, we'll remove this.

> 
>> +
>> +static inline void meson_elb_writel(struct meson_pcie *mp, u32 val, u32 reg)
>> +{
>> +	writel(val, mp->mem_res.elbi_base + reg);
>> +}
>> +
>> +static inline u32 meson_elb_readl(struct meson_pcie *mp, u32 reg)
>> +{
>> +	return readl(mp->mem_res.elbi_base + reg);
>> +}
>> +
>> +static inline u32 meson_cfg_readl(struct meson_pcie *mp, u32 reg)
>> +{
>> +	return readl(mp->mem_res.cfg_base + reg);
>> +}
>> +
>> +static inline void meson_cfg_writel(struct meson_pcie *mp, u32 val, u32 reg)
>> +{
>> +	writel(val, mp->mem_res.cfg_base + reg);
>> +}
>> +
>> +static void meson_pcie_assert_reset(struct meson_pcie *mp)
>> +{
>> +	gpiod_set_value_cansleep(mp->reset_gpio, 0);
>> +	udelay(500);
>> +	gpiod_set_value_cansleep(mp->reset_gpio, 1);
>> +}
>> +
>> +static void meson_pcie_init_dw(struct meson_pcie *mp)
>> +{
>> +	u32 val = 0;
>> +
>> +	val = meson_cfg_readl(mp, PCIE_CFG0);
>> +	val |= APP_LTSSM_ENABLE;
>> +	meson_cfg_writel(mp, val, PCIE_CFG0);
>> +
>> +	val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF);
>> +	val &= ~LINK_CAPABLE_MASK;
>> +	meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
>> +
>> +	val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF);
>> +	val |= LINK_CAPABLE_X1 | FAST_LINK_MODE;
>> +	meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
>> +
>> +	val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);
>> +	val &= ~NUM_OF_LANES_MASK;
>> +	meson_elb_writel(mp, val, PCIE_GEN2_CTRL_OFF);
>> +
>> +	val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);
>> +	val |= NUM_OF_LANES_X1 | DIRECT_SPEED_CHANGE;
>> +	meson_elb_writel(mp, val, PCIE_GEN2_CTRL_OFF);
>> +
>> +	meson_elb_writel(mp, 0x0, PCIE_BASE_ADDR0);
>> +	meson_elb_writel(mp, 0x0, PCIE_BASE_ADDR1);
>> +}
>> +
>> +static int meson_size_to_payload(int size)
>> +{
>> +	if (size & (size - 1) || size < 128 || size > 4096)
>> +		return 1;
>> +
>> +	return fls(size) - 8;
>> +}
>> +
>> +static void meson_set_max_payload(struct meson_pcie *mp, int size)
>> +{
>> +	u32 val = 0;
>> +	int max_payload_size = meson_size_to_payload(size);
>> +
>> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
>> +	val &= ~PCIE_CAP_MAX_PAYLOAD_MASK;
>> +	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
>> +
>> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
>> +	val |= PCIE_CAP_MAX_PAYLOAD_SIZE(max_payload_size);
>> +	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
>> +}
>> +
>> +static void meson_set_max_rd_req_size(struct meson_pcie *mp, int size)
>> +{
>> +	u32 val = 0;
>> +	int max_rd_req_size = meson_size_to_payload(size);
>> +
>> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
>> +	val &= ~PCIE_CAP_MAX_READ_REQ_MASK;
>> +	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
>> +
>> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
>> +	val |= PCIE_CAP_MAX_READ_REQ_SIZE(max_rd_req_size);
>> +	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
>> +}
>> +
>> +static inline void meson_enable_memory_space(struct meson_pcie *mp)
>> +{
>> +	/* Set the RC Bus Master, Memory Space and I/O Space enables */
>> +	meson_elb_writel(mp, PCI_IO_EN | PCI_MEM_SPACE_EN | PCI_BUS_MASTER_EN,
>> +			 PCIE_STATUS_COMMAND);
>> +}
>> +
>> +static int meson_pcie_establish_link(struct meson_pcie *mp)
>> +{
>> +	struct dw_pcie *pci = &mp->pci;
>> +	struct pcie_port *pp = &pci->pp;
>> +
>> +	meson_pcie_init_dw(mp);
>> +	meson_set_max_payload(mp, MAX_PAYLOAD_SIZE);
>> +	meson_set_max_rd_req_size(mp, MAX_READ_REQ_SIZE);
>> +
>> +	dw_pcie_setup_rc(pp);
>> +	meson_enable_memory_space(mp);
>> +
>> +	meson_pcie_assert_reset(mp);
>> +
>> +	/* check if the link is up or not */
>> +	if (!dw_pcie_wait_for_link(pci))
>> +		return 0;
>> +
>> +	return -ETIMEDOUT;
>> +}
>> +
>> +static void meson_pcie_msi_init(struct meson_pcie *mp)
>> +{
>> +	struct pcie_port *pp = &mp->pci.pp;
>> +
>> +	dw_pcie_msi_init(pp);
>> +}
>> +
>> +static void meson_pcie_enable_interrupts(struct meson_pcie *mp)
>> +{
>> +	if (IS_ENABLED(CONFIG_PCI_MSI))
>> +		meson_pcie_msi_init(mp);
>> +}
>> +
>> +static u32 meson_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base,
>> +			       u32 reg, size_t size)
>> +{
>> +	u32 val;
>> +
>> +	dw_pcie_read(base + reg, size, &val);
>> +
>> +	return val;
>> +}
>> +
>> +static void meson_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base,
>> +				 u32 reg, size_t size, u32 val)
>> +{
>> +	dw_pcie_write(base + reg, size, val);
>> +}
>> +
>> +static int meson_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
>> +				  u32 *val)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct meson_pcie *mp = to_meson_pcie(pci);
>> +
>> +	if (!mp->device_attch)
>> +		return 0;
>> +
>> +	/* the device class is not reported correctly from the register */
>> +	if (where == PCI_CLASS_REVISION) {
>> +		*val = readl(pci->dbi_base + PCI_CLASS_REVISION);
>> +		/* keep revision id */
>> +		*val &= PCI_CLASS_REVISION_MASK;
>> +		*val |= PCI_CLASS_BRIDGE_PCI << 16;
>> +		return PCIBIOS_SUCCESSFUL;
>> +	}
>> +
>> +	return dw_pcie_read(pci->dbi_base + where, size, val);
>> +}
>> +
>> +static int meson_pcie_wr_own_conf(struct pcie_port *pp, int where,
>> +				  int size, u32 val)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct meson_pcie *mp = to_meson_pcie(pci);
>> +
>> +	if (!mp->device_attch)
>> +		return 0;
>> +
>> +	return dw_pcie_write(pci->dbi_base + where, size, val);
>> +}
>> +
>> +static int meson_pcie_link_up(struct dw_pcie *pci)
>> +{
>> +	struct meson_pcie *mp = to_meson_pcie(pci);
>> +	struct device *dev = pci->dev;
>> +	u32 smlh_up = 0;
>> +	u32 ltssm_up = 0;
>> +	u32 rdlh_up = 0;
>> +	u32 speed_okay = 0;
>> +	u32 cnt = 0;
>> +	u32 state12, state17;
>> +
>> +	while (smlh_up == 0 || rdlh_up == 0 || ltssm_up == 0 ||
>> +	       speed_okay == 0) {
>> +		udelay(20);
>> +
>> +		state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12);
>> +		state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17);
>> +		smlh_up = IS_SMLH_LINK_UP(state12);
>> +		rdlh_up = IS_RDLH_LINK_UP(state12);
>> +		ltssm_up = IS_LTSSM_UP(state12);
>> +
>> +		if (PM_CURRENT_STATE(state17) < PCIE_GEN3)
>> +			speed_okay = 1;
>> +
>> +		if (smlh_up)
>> +			dev_dbg(dev, "smlh_link_up is on\n");
>> +		if (rdlh_up)
>> +			dev_dbg(dev, "rdlh_link_up is on\n");
>> +		if (ltssm_up)
>> +			dev_dbg(dev, "ltssm_up is on\n");
>> +		if (speed_okay)
>> +			dev_dbg(dev, "speed_okay\n");
>> +
>> +		cnt++;
>> +
>> +		if (cnt >= WAIT_LINKUP_TIMEOUT) {
>> +			dev_err(dev, "Error: Wait linkup timeout.\n");
>> +			return 0;
>> +		}
>> +	}
>> +
>> +	return 1;
>> +}
>> +
>> +static int meson_pcie_host_init(struct pcie_port *pp)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct meson_pcie *mp = to_meson_pcie(pci);
>> +	int ret;
>> +
>> +	ret = meson_pcie_establish_link(mp);
>> +
>> +	if (ret)
>> +		return ret;
>> +
>> +	mp->device_attch = 1;
>> +	meson_pcie_enable_interrupts(mp);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct dw_pcie_host_ops meson_pcie_host_ops = {
>> +	.rd_own_conf = meson_pcie_rd_own_conf,
>> +	.wr_own_conf = meson_pcie_wr_own_conf,
>> +	.host_init = meson_pcie_host_init,
>> +};
>> +
>> +static int meson_add_pcie_port(struct meson_pcie *mp,
>> +			       struct platform_device *pdev)
>> +{
>> +	struct dw_pcie *pci = &mp->pci;
>> +	struct pcie_port *pp = &pci->pp;
>> +	struct device *dev = &pdev->dev;
>> +	int ret;
>> +
>> +	if (IS_ENABLED(CONFIG_PCI_MSI)) {
>> +		pp->msi_irq = platform_get_irq(pdev, 0);
>> +		if (pp->msi_irq < 0) {
>> +			dev_err(dev, "failed to get msi irq\n");
>> +			return pp->msi_irq;
>> +		}
>> +	}
>> +
>> +	pp->root_bus_nr = -1;
>> +	pp->ops = &meson_pcie_host_ops;
>> +	pci->dbi_base = mp->mem_res.elbi_base;
>> +
>> +	ret = dw_pcie_host_init(pp);
>> +	if (ret) {
>> +		dev_err(dev, "failed to initialize host\n");
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct dw_pcie_ops dw_pcie_ops = {
>> +	.read_dbi = meson_pcie_read_dbi,
>> +	.write_dbi = meson_pcie_write_dbi,
>> +	.link_up = meson_pcie_link_up,
>> +};
>> +
>> +static int meson_pcie_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct dw_pcie *pci;
>> +	struct meson_pcie *mp;
>> +	struct meson_pcie_rc_reset *mrst;
>> +	int ret;
>> +
>> +	mp = devm_kzalloc(dev, sizeof(*mp), GFP_KERNEL);
>> +	if (!mp)
>> +		return -ENOMEM;
>> +
>> +	pci = &mp->pci;
>> +	pci->dev = dev;
>> +	pci->ops = &dw_pcie_ops;
>> +
>> +	mp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
>> +	if (IS_ERR(mp->reset_gpio)) {
>> +		dev_err(dev, "Get reset gpio failed\n");
>> +		return PTR_ERR(mp->reset_gpio);
>> +	}
>> +
>> +	mp->phy = devm_of_phy_get(dev, np, NULL);
> 
> For the 3rd time, you do *not* need a phy driver to just handle a reset line.
> It is overkill.
> 
> you should claim the shared reset line here and be done with it.
> 

As your suggestion, we'll integrate phy driver into the controller and use 
shared reset line here.

>> +	if (IS_ERR(mp->phy)) {
>> +		if (PTR_ERR(mp->phy) != -EPROBE_DEFER)
>> +			dev_err(dev, "Get phy failed, set default %ld\n",
>> +				PTR_ERR(mp->phy));
>> +		return PTR_ERR(mp->phy);
>> +	}
>> +
>> +	mrst = &mp->mrst;
>> +
>> +	mrst->port = devm_reset_control_get_shared(dev, "port");
> 
> There is no reason for this reset to be shared since there is one per pcie port.
> 

Yes, we will correct it.
Thanks for suggestions.

>> +	if (IS_ERR(mrst->port)) {
>> +		if (PTR_ERR(mrst->port) != -EPROBE_DEFER)
>> +			dev_err(dev, "couldn't get port reset %ld\n",
>> +				PTR_ERR(mrst->port));
>> +
>> +		return PTR_ERR(mrst->port);
>> +	}
>> +
>> +	mrst->apb = devm_reset_control_get_shared(dev, "apb");
>> +	if (IS_ERR(mrst->apb)) {
>> +		if (PTR_ERR(mrst->apb) != -EPROBE_DEFER)
>> +			dev_err(dev, "couldn't get apb reset\n");
>> +
>> +		return PTR_ERR(mrst->apb);
>> +	}
>> +
>> +	reset_control_deassert(mrst->port);
>> +	reset_control_deassert(mrst->apb);
>> +
>> +	phy_power_on(mp->phy);
>> +
>> +	ret = meson_pcie_init_clk(mp);
>> +	if (ret) {
>> +		dev_err(dev, "Init clock resources failed, %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = meson_pcie_get_mem(pdev, mp);
>> +	if (ret) {
>> +		dev_err(dev, "Get memory resource failed, %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, mp);
>> +
>> +	ret = meson_add_pcie_port(mp, pdev);
>> +	if (ret < 0) {
>> +		dev_err(dev, "Add PCIE port failed, %d\n", ret);
>> +		meson_pcie_deinit_clk(mp);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static const struct of_device_id meson_pcie_of_match[] = {
>> +	{
>> +		.compatible = "amlogic,axg-pcie",
>> +	},
>> +	{},
>> +};
>> +
>> +static struct platform_driver meson_pcie_driver = {
>> +	.probe = meson_pcie_probe,
>> +	.driver = {
>> +		.name = "meson-pcie",
>> +		.of_match_table = meson_pcie_of_match,
>> +	},
>> +};
>> +
>> +builtin_platform_driver(meson_pcie_driver);
> 
> 
> .
>