[PATCH 0/5] PCI: dwc: rcar-gen4: Add support for R-Car X5H PCIe4

[PATCH 0/5] PCI: dwc: rcar-gen4: Add support for R-Car X5H PCIe4

[Marek Vasut]

Add support for R8A78000 (R-Car X5H) PCIe4.

This driver previously supported R-Car Gen4 S4/V4H/V4M. PCIe features
of R-Car X5H PCIe4 are almost all the same, except for different PHY
which has its own driver, slightly different initialization code and
the DMA is no longer eDMA but HDMA.

Endpoint mode is currently not implemented for R-Car Gen5 PCIe4.

Depends:
PCI: rcar-gen4: irqchip/gic-v3: Handle GIC ITS
https://lore.kernel.org/all/20260701203918.63189-1-marek.vasut+renesas@mailbox.org/

Marek Vasut (5):
  dt-bindings: PCI: rcar-gen4-pci-host: Add R-Car X5H PCIe4 compatible
  PCI: dwc: rcar-gen4: Return error code from .additional_common_init
  PCI: dwc: rcar-gen4: Split .start_link into ltssm_control and
    speed_control
  PCI: dwc: rcar-gen4: Handle PERST via reset subsystem
  PCI: dwc: rcar-gen4: Add support for R-Car X5H PCIe4

 .../bindings/pci/rcar-gen4-pci-host.yaml      |  74 +++++--
 drivers/pci/controller/dwc/pcie-rcar-gen4.c   | 209 ++++++++++++++++--
 2 files changed, 239 insertions(+), 44 deletions(-)

---
Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org

-- 
2.53.0

[PATCH 1/5] dt-bindings: PCI: rcar-gen4-pci-host: Add R-Car X5H PCIe4 compatible

[Marek Vasut]

Document bindings for R-Car X5H (R8A78000) PCIe4 host module.

The binding document is deliberately using "renesas,rcar-gen5-pcie4"
DT compatible string to discern R-Car X5H PCIe4 controller supported
by this binding, from R-Car X5H PCIe6 controller which will use a
separate binding.

The R-Car X5H PCIe4 controller does no longer include PHY register
range, the PHY is now a separate IP and referenced via the 'phy' DT
property. The 'reg' and 'reg-names' DT properties therefore differ
between R-Car Gen4 PCIe and R-Car X5H PCIe4, and the difference is
handled in the allOf section.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
 .../bindings/pci/rcar-gen4-pci-host.yaml      | 74 +++++++++++++------
 1 file changed, 52 insertions(+), 22 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/rcar-gen4-pci-host.yaml b/Documentation/devicetree/bindings/pci/rcar-gen4-pci-host.yaml
index bb3f843c59d91..9733704331b56 100644
--- a/Documentation/devicetree/bindings/pci/rcar-gen4-pci-host.yaml
+++ b/Documentation/devicetree/bindings/pci/rcar-gen4-pci-host.yaml
@@ -10,30 +10,20 @@ title: Renesas R-Car Gen4 PCIe Host
 maintainers:
   - Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
 
-allOf:
-  - $ref: snps,dw-pcie.yaml#
-
 properties:
   compatible:
-    items:
-      - enum:
-          - renesas,r8a779f0-pcie      # R-Car S4-8
-          - renesas,r8a779g0-pcie      # R-Car V4H
-          - renesas,r8a779h0-pcie      # R-Car V4M
-      - const: renesas,rcar-gen4-pcie  # R-Car Gen4
-
-  reg:
-    maxItems: 7
-
-  reg-names:
-    items:
-      - const: dbi
-      - const: dbi2
-      - const: atu
-      - const: dma
-      - const: app
-      - const: phy
-      - const: config
+    oneOf:
+      - items:
+          - enum:
+              - renesas,r8a779f0-pcie      # R-Car S4-8
+              - renesas,r8a779g0-pcie      # R-Car V4H
+              - renesas,r8a779h0-pcie      # R-Car V4M
+          - const: renesas,rcar-gen4-pcie  # R-Car Gen4
+
+      - items:
+          - enum:
+              - renesas,r8a78000-pcie4     # R-Car X5H PCIe4
+          - const: renesas,rcar-gen5-pcie4 # R-Car Gen5 PCIe4
 
   interrupts:
     maxItems: 4
@@ -81,6 +71,46 @@ required:
   - resets
   - reset-names
 
+allOf:
+  - $ref: snps,dw-pcie.yaml#
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: renesas,rcar-gen4-pcie
+    then:
+      properties:
+        reg:
+          maxItems: 7
+
+        reg-names:
+          items:
+            - const: dbi
+            - const: dbi2
+            - const: atu
+            - const: dma
+            - const: app
+            - const: phy
+            - const: config
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: renesas,rcar-gen5-pcie4
+    then:
+      properties:
+        reg:
+          maxItems: 6
+
+        reg-names:
+          items:
+            - const: dbi
+            - const: dbi2
+            - const: atu
+            - const: dma
+            - const: app
+            - const: config
+
 unevaluatedProperties: false
 
 examples:
-- 
2.53.0

Re: [PATCH 1/5] dt-bindings: PCI: rcar-gen4-pci-host: Add R-Car X5H PCIe4 compatible

[Krzysztof Kozlowski]

On Sat, Jul 04, 2026 at 10:25:00PM +0200, Marek Vasut wrote:
> Document bindings for R-Car X5H (R8A78000) PCIe4 host module.
> 
> The binding document is deliberately using "renesas,rcar-gen5-pcie4"
> DT compatible string to discern R-Car X5H PCIe4 controller supported
> by this binding, from R-Car X5H PCIe6 controller which will use a
> separate binding.
> 
> The R-Car X5H PCIe4 controller does no longer include PHY register
> range, the PHY is now a separate IP and referenced via the 'phy' DT
> property. The 'reg' and 'reg-names' DT properties therefore differ
> between R-Car Gen4 PCIe and R-Car X5H PCIe4, and the difference is
> handled in the allOf section.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Best regards,
Krzysztof

[PATCH 2/5] PCI: dwc: rcar-gen4: Return error code from .additional_common_init

[Marek Vasut]

Return error code from .additional_common_init callback and check
the error code. This is a preparatory patch for R-Car Gen5 support,
which may return non-zero error code from .additional_common_init.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
 drivers/pci/controller/dwc/pcie-rcar-gen4.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index 5f7211b91ee5b..7625cd338262d 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -87,7 +87,7 @@ MODULE_FIRMWARE(RCAR_GEN4_PCIE_FIRMWARE_NAME);
 
 struct rcar_gen4_pcie;
 struct rcar_gen4_pcie_drvdata {
-	void (*additional_common_init)(struct rcar_gen4_pcie *rcar);
+	int (*additional_common_init)(struct rcar_gen4_pcie *rcar);
 	int (*ltssm_control)(struct rcar_gen4_pcie *rcar, bool enable);
 	enum dw_pcie_device_mode mode;
 };
@@ -241,11 +241,16 @@ static int rcar_gen4_pcie_common_init(struct rcar_gen4_pcie *rcar)
 	reset_control_status(dw->core_rsts[DW_PCIE_PWR_RST].rstc);
 	fsleep(1000);
 
-	if (rcar->drvdata->additional_common_init)
-		rcar->drvdata->additional_common_init(rcar);
+	if (rcar->drvdata->additional_common_init) {
+		ret = rcar->drvdata->additional_common_init(rcar);
+		if (ret)
+			goto err_deassert;
+	}
 
 	return 0;
 
+err_deassert:
+	reset_control_assert(dw->core_rsts[DW_PCIE_PWR_RST].rstc);
 err_unprepare:
 	clk_bulk_disable_unprepare(DW_PCIE_NUM_CORE_CLKS, dw->core_clks);
 
@@ -681,7 +686,7 @@ static int r8a779f0_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable)
 	return 0;
 }
 
-static void rcar_gen4_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
+static int rcar_gen4_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
 {
 	struct dw_pcie *dw = &rcar->dw;
 	u32 val;
@@ -695,6 +700,8 @@ static void rcar_gen4_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
 	val = readl(rcar->base + PCIEPWRMNGCTRL);
 	val |= APP_CLK_REQ_N | APP_CLK_PM_EN;
 	writel(val, rcar->base + PCIEPWRMNGCTRL);
+
+	return 0;
 }
 
 static void rcar_gen4_pcie_phy_reg_update_bits(struct rcar_gen4_pcie *rcar,
-- 
2.53.0

Re: [PATCH 2/5] PCI: dwc: rcar-gen4: Return error code from .additional_common_init

[Manivannan Sadhasivam]

On Sat, Jul 04, 2026 at 10:25:01PM +0200, Marek Vasut wrote:
> Return error code from .additional_common_init callback and check
> the error code. This is a preparatory patch for R-Car Gen5 support,
> which may return non-zero error code from .additional_common_init.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> ---
> Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> Cc: Manivannan Sadhasivam <mani@kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-pci@vger.kernel.org
> Cc: linux-renesas-soc@vger.kernel.org
> ---
>  drivers/pci/controller/dwc/pcie-rcar-gen4.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> index 5f7211b91ee5b..7625cd338262d 100644
> --- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> @@ -87,7 +87,7 @@ MODULE_FIRMWARE(RCAR_GEN4_PCIE_FIRMWARE_NAME);
>  
>  struct rcar_gen4_pcie;
>  struct rcar_gen4_pcie_drvdata {
> -	void (*additional_common_init)(struct rcar_gen4_pcie *rcar);
> +	int (*additional_common_init)(struct rcar_gen4_pcie *rcar);

Can you also rename this callback as init() and implementations as
rcar_gen4_pcie_{ep}_init()?

Though this callback is a grab-bag of various register settings, naming it as
just '.init()' will make it more readable and less redundant.

- Mani

>  	int (*ltssm_control)(struct rcar_gen4_pcie *rcar, bool enable);
>  	enum dw_pcie_device_mode mode;
>  };
> @@ -241,11 +241,16 @@ static int rcar_gen4_pcie_common_init(struct rcar_gen4_pcie *rcar)
>  	reset_control_status(dw->core_rsts[DW_PCIE_PWR_RST].rstc);
>  	fsleep(1000);
>  
> -	if (rcar->drvdata->additional_common_init)
> -		rcar->drvdata->additional_common_init(rcar);
> +	if (rcar->drvdata->additional_common_init) {
> +		ret = rcar->drvdata->additional_common_init(rcar);
> +		if (ret)
> +			goto err_deassert;
> +	}
>  
>  	return 0;
>  
> +err_deassert:
> +	reset_control_assert(dw->core_rsts[DW_PCIE_PWR_RST].rstc);
>  err_unprepare:
>  	clk_bulk_disable_unprepare(DW_PCIE_NUM_CORE_CLKS, dw->core_clks);
>  
> @@ -681,7 +686,7 @@ static int r8a779f0_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable)
>  	return 0;
>  }
>  
> -static void rcar_gen4_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
> +static int rcar_gen4_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
>  {
>  	struct dw_pcie *dw = &rcar->dw;
>  	u32 val;
> @@ -695,6 +700,8 @@ static void rcar_gen4_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
>  	val = readl(rcar->base + PCIEPWRMNGCTRL);
>  	val |= APP_CLK_REQ_N | APP_CLK_PM_EN;
>  	writel(val, rcar->base + PCIEPWRMNGCTRL);
> +
> +	return 0;
>  }
>  
>  static void rcar_gen4_pcie_phy_reg_update_bits(struct rcar_gen4_pcie *rcar,
> -- 
> 2.53.0
> 

-- 
மணிவண்ணன் சதாசிவம்

[PATCH 3/5] PCI: dwc: rcar-gen4: Split .start_link into ltssm_control and speed_control

[Marek Vasut]

Introduce new .speed_control callback and implement it on R-Car Gen4.
The callback implements the second half of what is currently present
in rcar_gen4_pcie_start_link(), and rcar_gen4_pcie_start_link() does
call the .speed_control callback. This is a preparatory patch for
R-Car Gen5 support, where the .speed_control implementation is
different.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
 drivers/pci/controller/dwc/pcie-rcar-gen4.c | 39 ++++++++++++++-------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index 7625cd338262d..05c22cc648135 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -89,6 +89,7 @@ struct rcar_gen4_pcie;
 struct rcar_gen4_pcie_drvdata {
 	int (*additional_common_init)(struct rcar_gen4_pcie *rcar);
 	int (*ltssm_control)(struct rcar_gen4_pcie *rcar, bool enable);
+	int (*speed_control)(struct rcar_gen4_pcie *rcar);
 	enum dw_pcie_device_mode mode;
 };
 
@@ -140,20 +141,10 @@ static int rcar_gen4_pcie_speed_change(struct dw_pcie *dw)
 	return -ETIMEDOUT;
 }
 
-/*
- * Enable LTSSM of this controller and manually initiate the speed change.
- * Always return 0.
- */
-static int rcar_gen4_pcie_start_link(struct dw_pcie *dw)
+static int rcar_gen4_pcie_speed_control(struct rcar_gen4_pcie *rcar)
 {
-	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
-	int i, changes, ret;
-
-	if (rcar->drvdata->ltssm_control) {
-		ret = rcar->drvdata->ltssm_control(rcar, true);
-		if (ret)
-			return ret;
-	}
+	struct dw_pcie *dw = &rcar->dw;
+	int i, changes;
 
 	/*
 	 * Require direct speed change with retrying here if the max_link_speed
@@ -177,6 +168,24 @@ static int rcar_gen4_pcie_start_link(struct dw_pcie *dw)
 	return 0;
 }
 
+/*
+ * Enable LTSSM of this controller and manually initiate the speed change.
+ * Always return 0.
+ */
+static int rcar_gen4_pcie_start_link(struct dw_pcie *dw)
+{
+	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
+	int ret;
+
+	if (rcar->drvdata->ltssm_control) {
+		ret = rcar->drvdata->ltssm_control(rcar, true);
+		if (ret)
+			return ret;
+	}
+
+	return rcar->drvdata->speed_control(rcar);
+}
+
 static void rcar_gen4_pcie_stop_link(struct dw_pcie *dw)
 {
 	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
@@ -856,23 +865,27 @@ static int rcar_gen4_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable
 
 static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie = {
 	.ltssm_control = r8a779f0_pcie_ltssm_control,
+	.speed_control = rcar_gen4_pcie_speed_control,
 	.mode = DW_PCIE_RC_TYPE,
 };
 
 static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie_ep = {
 	.ltssm_control = r8a779f0_pcie_ltssm_control,
+	.speed_control = rcar_gen4_pcie_speed_control,
 	.mode = DW_PCIE_EP_TYPE,
 };
 
 static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen4_pcie = {
 	.additional_common_init = rcar_gen4_pcie_additional_common_init,
 	.ltssm_control = rcar_gen4_pcie_ltssm_control,
+	.speed_control = rcar_gen4_pcie_speed_control,
 	.mode = DW_PCIE_RC_TYPE,
 };
 
 static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen4_pcie_ep = {
 	.additional_common_init = rcar_gen4_pcie_additional_common_init,
 	.ltssm_control = rcar_gen4_pcie_ltssm_control,
+	.speed_control = rcar_gen4_pcie_speed_control,
 	.mode = DW_PCIE_EP_TYPE,
 };
 
-- 
2.53.0

[PATCH 4/5] PCI: dwc: rcar-gen4: Handle PERST via reset subsystem

[Marek Vasut]

Handle PERST via both GPIO and reset subsystem. On R-Car Gen4, the
PERST signal is operated as a GPIO, on R-Car Gen5 it might only be
accessible via SCMI reset via reset subsystem. Support both options.
This is a preparatory patch for R-Car Gen5 support.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
 drivers/pci/controller/dwc/pcie-rcar-gen4.c | 42 +++++++++++++++++++--
 1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index 05c22cc648135..186eedb33c27d 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -98,6 +98,7 @@ struct rcar_gen4_pcie {
 	void __iomem *base;
 	void __iomem *phy_base;
 	struct platform_device *pdev;
+	struct reset_control *perst;
 	const struct rcar_gen4_pcie_drvdata *drvdata;
 };
 #define to_rcar_gen4_pcie(_dw)	container_of(_dw, struct rcar_gen4_pcie, dw)
@@ -299,10 +300,27 @@ static void rcar_gen4_pcie_unprepare(struct rcar_gen4_pcie *rcar)
 
 static int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar)
 {
+	struct device *dev = rcar->dw.dev;
+	struct reset_control *perst;
+
 	rcar->phy_base = devm_platform_ioremap_resource_byname(rcar->pdev, "phy");
 	if (IS_ERR(rcar->phy_base))
 		return PTR_ERR(rcar->phy_base);
 
+	rcar->perst = NULL;
+	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
+		perst = of_reset_control_get(of_port, "perst");
+		if (IS_ERR(perst)) {
+			if (PTR_ERR(perst) != -EPROBE_DEFER)
+				dev_err(dev, "Failed to get PERST#\n");
+			return PTR_ERR(perst);
+		}
+
+		/* There is only one root port. */
+		rcar->perst = perst;
+		break;
+	}
+
 	/* Renesas-specific registers */
 	rcar->base = devm_platform_ioremap_resource_byname(rcar->pdev, "app");
 
@@ -425,6 +443,22 @@ static int rcar_gen4_pcie_host_msi_init(struct dw_pcie_rp *pp)
 	return ret;
 }
 
+static void rcar_gen4_pcie_host_perst(struct dw_pcie_rp *pp, int enable)
+{
+	struct dw_pcie *dw = to_dw_pcie_from_pp(pp);
+	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
+
+	gpiod_set_value_cansleep(dw->pe_rst, enable);
+
+	if (!rcar->perst)
+		return;
+
+	if (enable)
+		reset_control_assert(rcar->perst);
+	else
+		reset_control_deassert(rcar->perst);
+}
+
 /* Host mode */
 static int rcar_gen4_pcie_host_init(struct dw_pcie_rp *pp)
 {
@@ -432,7 +466,7 @@ static int rcar_gen4_pcie_host_init(struct dw_pcie_rp *pp)
 	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
 	int ret;
 
-	gpiod_set_value_cansleep(dw->pe_rst, 1);
+	rcar_gen4_pcie_host_perst(pp, 1);
 
 	ret = rcar_gen4_pcie_common_init(rcar);
 	if (ret)
@@ -453,7 +487,7 @@ static int rcar_gen4_pcie_host_init(struct dw_pcie_rp *pp)
 
 	msleep(PCIE_T_PVPERL_MS);	/* pe_rst requires 100msec delay */
 
-	gpiod_set_value_cansleep(dw->pe_rst, 0);
+	rcar_gen4_pcie_host_perst(pp, 0);
 
 	return 0;
 
@@ -467,7 +501,7 @@ static void rcar_gen4_pcie_host_deinit(struct dw_pcie_rp *pp)
 	struct dw_pcie *dw = to_dw_pcie_from_pp(pp);
 	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
 
-	gpiod_set_value_cansleep(dw->pe_rst, 1);
+	rcar_gen4_pcie_host_perst(pp, 1);
 	rcar_gen4_pcie_common_deinit(rcar);
 }
 
@@ -671,6 +705,8 @@ static void rcar_gen4_pcie_remove(struct platform_device *pdev)
 
 	rcar_gen4_remove_dw_pcie(rcar);
 	rcar_gen4_pcie_unprepare(rcar);
+	if (rcar->perst)
+		reset_control_put(rcar->perst);
 }
 
 static int r8a779f0_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable)
-- 
2.53.0

Re: [PATCH 4/5] PCI: dwc: rcar-gen4: Handle PERST via reset subsystem

[Geert Uytterhoeven]

Hi Marek,

On Sat, 4 Jul 2026 at 22:28, Marek Vasut
<marek.vasut+renesas@mailbox.org> wrote:
> Handle PERST via both GPIO and reset subsystem. On R-Car Gen4, the
> PERST signal is operated as a GPIO, on R-Car Gen5 it might only be
> accessible via SCMI reset via reset subsystem. Support both options.
> This is a preparatory patch for R-Car Gen5 support.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

Thanks for your patch!

> --- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c

> @@ -299,10 +300,27 @@ static void rcar_gen4_pcie_unprepare(struct rcar_gen4_pcie *rcar)
>
>  static int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar)
>  {
> +       struct device *dev = rcar->dw.dev;
> +       struct reset_control *perst;
> +
>         rcar->phy_base = devm_platform_ioremap_resource_byname(rcar->pdev, "phy");
>         if (IS_ERR(rcar->phy_base))
>                 return PTR_ERR(rcar->phy_base);
>
> +       rcar->perst = NULL;
> +       for_each_available_child_of_node_scoped(dev->of_node, of_port) {
> +               perst = of_reset_control_get(of_port, "perst");
> +               if (IS_ERR(perst)) {
> +                       if (PTR_ERR(perst) != -EPROBE_DEFER)
> +                               dev_err(dev, "Failed to get PERST#\n");
> +                       return PTR_ERR(perst);

return dev_err_probe(...)?

This error condition is triggered on Sparrow Hawk and White Hawk,
as their DTS does not have perst:

    pcie-rcar-gen4 e65d0000.pcie: Failed to get PERST#
    pcie-rcar-gen4 e65d0000.pcie: probe with driver pcie-rcar-gen4
failed with error -2

Gr{oetje,eeting}s,

                        Geert

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

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

Re: [PATCH 4/5] PCI: dwc: rcar-gen4: Handle PERST via reset subsystem

[Manivannan Sadhasivam]

On Sat, Jul 04, 2026 at 10:25:03PM +0200, Marek Vasut wrote:
> Handle PERST via both GPIO and reset subsystem. On R-Car Gen4, the
> PERST signal is operated as a GPIO, on R-Car Gen5 it might only be
> accessible via SCMI reset via reset subsystem. Support both options.
> This is a preparatory patch for R-Car Gen5 support.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> ---
> Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> Cc: Manivannan Sadhasivam <mani@kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-pci@vger.kernel.org
> Cc: linux-renesas-soc@vger.kernel.org
> ---
>  drivers/pci/controller/dwc/pcie-rcar-gen4.c | 42 +++++++++++++++++++--
>  1 file changed, 39 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> index 05c22cc648135..186eedb33c27d 100644
> --- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> @@ -98,6 +98,7 @@ struct rcar_gen4_pcie {
>  	void __iomem *base;
>  	void __iomem *phy_base;
>  	struct platform_device *pdev;
> +	struct reset_control *perst;
>  	const struct rcar_gen4_pcie_drvdata *drvdata;
>  };
>  #define to_rcar_gen4_pcie(_dw)	container_of(_dw, struct rcar_gen4_pcie, dw)
> @@ -299,10 +300,27 @@ static void rcar_gen4_pcie_unprepare(struct rcar_gen4_pcie *rcar)
>  
>  static int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar)
>  {
> +	struct device *dev = rcar->dw.dev;
> +	struct reset_control *perst;
> +
>  	rcar->phy_base = devm_platform_ioremap_resource_byname(rcar->pdev, "phy");
>  	if (IS_ERR(rcar->phy_base))
>  		return PTR_ERR(rcar->phy_base);
>  
> +	rcar->perst = NULL;
> +	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
> +		perst = of_reset_control_get(of_port, "perst");
> +		if (IS_ERR(perst)) {
> +			if (PTR_ERR(perst) != -EPROBE_DEFER)
> +				dev_err(dev, "Failed to get PERST#\n");
> +			return PTR_ERR(perst);

return dev_err_probe(dev, PTR_ERR(perst), "Failed to get PERST#\n")?

> +		}
> +
> +		/* There is only one root port. */
> +		rcar->perst = perst;
> +		break;

It feels weird to see for_each_available_child_of_node_scoped() and then
breaking with first node. Maybe you can just use of_get_next_available_child().

> +	}
> +
>  	/* Renesas-specific registers */
>  	rcar->base = devm_platform_ioremap_resource_byname(rcar->pdev, "app");
>  
> @@ -425,6 +443,22 @@ static int rcar_gen4_pcie_host_msi_init(struct dw_pcie_rp *pp)
>  	return ret;
>  }
>  
> +static void rcar_gen4_pcie_host_perst(struct dw_pcie_rp *pp, int enable)
> +{

rcar_gen4_pcie_host_perst_assert(struct dw_pcie_rp *pp, bool assert)

> +	struct dw_pcie *dw = to_dw_pcie_from_pp(pp);
> +	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
> +
> +	gpiod_set_value_cansleep(dw->pe_rst, enable);
> +
> +	if (!rcar->perst)
> +		return;
> +
> +	if (enable)
> +		reset_control_assert(rcar->perst);
> +	else
> +		reset_control_deassert(rcar->perst);
> +}
> +
>  /* Host mode */
>  static int rcar_gen4_pcie_host_init(struct dw_pcie_rp *pp)
>  {
> @@ -432,7 +466,7 @@ static int rcar_gen4_pcie_host_init(struct dw_pcie_rp *pp)
>  	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
>  	int ret;
>  
> -	gpiod_set_value_cansleep(dw->pe_rst, 1);
> +	rcar_gen4_pcie_host_perst(pp, 1);
>  
>  	ret = rcar_gen4_pcie_common_init(rcar);
>  	if (ret)
> @@ -453,7 +487,7 @@ static int rcar_gen4_pcie_host_init(struct dw_pcie_rp *pp)
>  
>  	msleep(PCIE_T_PVPERL_MS);	/* pe_rst requires 100msec delay */
>  
> -	gpiod_set_value_cansleep(dw->pe_rst, 0);
> +	rcar_gen4_pcie_host_perst(pp, 0);

rcar_gen4_pcie_host_perst_assert(pp, false)

>  
>  	return 0;
>  
> @@ -467,7 +501,7 @@ static void rcar_gen4_pcie_host_deinit(struct dw_pcie_rp *pp)
>  	struct dw_pcie *dw = to_dw_pcie_from_pp(pp);
>  	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
>  
> -	gpiod_set_value_cansleep(dw->pe_rst, 1);
> +	rcar_gen4_pcie_host_perst(pp, 1);

rcar_gen4_pcie_host_perst_assert(pp, true)

>  	rcar_gen4_pcie_common_deinit(rcar);
>  }
>  
> @@ -671,6 +705,8 @@ static void rcar_gen4_pcie_remove(struct platform_device *pdev)
>  
>  	rcar_gen4_remove_dw_pcie(rcar);
>  	rcar_gen4_pcie_unprepare(rcar);
> +	if (rcar->perst)
> +		reset_control_put(rcar->perst);

I don't see reset_control_put() in any error paths of probe().

- Mani

-- 
மணிவண்ணன் சதாசிவம்

[PATCH 5/5] PCI: dwc: rcar-gen4: Add support for R-Car X5H PCIe4

[Marek Vasut]

Add support for R8A78000 (R-Car X5H) PCIe4.

This driver previously supported R-Car Gen4 S4/V4H/V4M. PCIe features
of R-Car X5H PCIe4 are almost all the same.

The controller initialization sequence is slightly different and is
factored out into controller specific callbacks, in a manner similar
to previous R-Car Gen4 handling.

The controller does have a PHY attached to it, but the PHY is operated
by a separate PHY driver, the PHY driver instance binding is handled
in rcar_gen4_pcie_get_resources() and controlled in the aforementioned
controller specific callbacks.

The controller driver is deliberately using "renesas,rcar-gen5-pcie4"
DT compatible string to discern R-Car X5H PCIe4 controller supported
by this driver, from R-Car X5H PCIe6 controller which will most likely
use a separate driver.

The R-Car X5H PCIe4 controller embeds HDMA instead of EDMA embedded
in the R-Car Gen4 PCIe controller, "dw-edma" driver supports both
DMA variants.

Endpoint mode is currently not implemented for R-Car Gen5 PCIe4.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
 drivers/pci/controller/dwc/pcie-rcar-gen4.c | 113 +++++++++++++++++++-
 1 file changed, 111 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index 186eedb33c27d..55c40424937c1 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -19,6 +19,7 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/pci.h>
+#include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
@@ -36,6 +37,7 @@
 
 /* MSI Capability */
 #define MSICAP0			0x0050
+#define MSICAP0_MMESCAP_MASK	GENMASK(19, 17)
 #define MSICAP0_MSIE		BIT(16)
 
 /* PCIe Interrupt Status 0 */
@@ -74,6 +76,11 @@
 #define PCIEPWRMNGCTRL		0x0070
 #define APP_CLK_REQ_N		BIT(11)
 #define APP_CLK_PM_EN		BIT(10)
+#define APP_READY_ENTR_L23	BIT(6)
+#define APP_REQ_ENTR_L1		BIT(5)
+
+/* PCI Express capability */
+#define EXPCAP(x)		(0x0070 + (x))
 
 #define RCAR_NUM_SPEED_CHANGE_RETRIES	10
 #define RCAR_MAX_LINK_SPEED		4
@@ -97,6 +104,7 @@ struct rcar_gen4_pcie {
 	struct dw_pcie dw;
 	void __iomem *base;
 	void __iomem *phy_base;
+	struct phy *phy;
 	struct platform_device *pdev;
 	struct reset_control *perst;
 	const struct rcar_gen4_pcie_drvdata *drvdata;
@@ -169,6 +177,35 @@ static int rcar_gen4_pcie_speed_control(struct rcar_gen4_pcie *rcar)
 	return 0;
 }
 
+static int rcar_gen5_pcie_speed_control(struct rcar_gen4_pcie *rcar)
+{
+	struct dw_pcie *dw = &rcar->dw;
+	u32 lnkcap = dw_pcie_readl_dbi(dw, EXPCAP(PCI_EXP_LNKCAP));
+	u32 lnksta = dw_pcie_readw_dbi(dw, EXPCAP(PCI_EXP_LNKSTA));
+	u32 val, retries;
+
+	if ((lnksta & PCI_EXP_LNKSTA_CLS) == (lnkcap & PCI_EXP_LNKCAP_SLS))
+		return 0;
+
+	/* Retrain link */
+	val = dw_pcie_readl_dbi(dw, EXPCAP(PCI_EXP_LNKCTL));
+	val |= PCI_EXP_LNKCTL_RL;
+	dw_pcie_writel_dbi(dw, EXPCAP(PCI_EXP_LNKCTL), val);
+
+	/* Wait for link retrain */
+	for (retries = 0; retries <= 10; retries++) {
+		lnksta = dw_pcie_readw_dbi(dw, EXPCAP(PCI_EXP_LNKSTA));
+
+		/* Check retrain flag */
+		if (!(lnksta & PCI_EXP_LNKSTA_LT))
+			break;
+
+		usleep_range(1000, 1100);
+	}
+
+	return 0;
+}
+
 /*
  * Enable LTSSM of this controller and manually initiate the speed change.
  * Always return 0.
@@ -304,8 +341,11 @@ static int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar)
 	struct reset_control *perst;
 
 	rcar->phy_base = devm_platform_ioremap_resource_byname(rcar->pdev, "phy");
-	if (IS_ERR(rcar->phy_base))
-		return PTR_ERR(rcar->phy_base);
+	if (IS_ERR(rcar->phy_base)) {
+		rcar->phy = devm_phy_get(dev, NULL);
+		if (IS_ERR(rcar->phy))
+			return PTR_ERR(rcar->phy);
+	}
 
 	rcar->perst = NULL;
 	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
@@ -731,6 +771,28 @@ static int r8a779f0_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable)
 	return 0;
 }
 
+static int rcar_gen5_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable)
+{
+	u32 val;
+
+	val = readl(rcar->base + PCIERSTCTRL1);
+	if (enable) {
+		val |= APP_LTSSM_ENABLE;
+		val &= ~APP_HOLD_PHY_RST;
+	} else {
+		val &= ~APP_LTSSM_ENABLE;
+		val |= APP_HOLD_PHY_RST;
+	}
+	writel(val, rcar->base + PCIERSTCTRL1);
+
+	if (enable)
+		phy_power_on(rcar->phy);
+	else
+		phy_power_off(rcar->phy);
+
+	return 0;
+}
+
 static int rcar_gen4_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
 {
 	struct dw_pcie *dw = &rcar->dw;
@@ -749,6 +811,42 @@ static int rcar_gen4_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
 	return 0;
 }
 
+static int rcar_gen5_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
+{
+	struct dw_pcie *dw = &rcar->dw;
+	int ret;
+	u32 val;
+
+	ret = phy_set_mode(rcar->phy, PHY_MODE_PCIE);
+	if (ret)
+		return ret;
+
+	ret = phy_init(rcar->phy);
+	if (ret)
+		return ret;
+
+	dw_pcie_dbi_ro_wr_en(dw);
+
+	val = dw_pcie_readl_dbi(dw, PCIE_PORT_LANE_SKEW);
+	val &= ~PORT_LANE_SKEW_INSERT_MASK;
+	if (dw->num_lanes < 8)
+		val |= BIT(6);
+	dw_pcie_writel_dbi(dw, PCIE_PORT_LANE_SKEW, val);
+
+	val = dw_pcie_readl_dbi(dw, MSICAP0);
+	FIELD_MODIFY(MSICAP0_MMESCAP_MASK, &val, 4);
+	dw_pcie_writel_dbi(dw, MSICAP0, val);
+
+	dw_pcie_dbi_ro_wr_dis(dw);
+
+	val = readl(rcar->base + PCIEPWRMNGCTRL);
+	val |= APP_CLK_REQ_N | APP_CLK_PM_EN |
+	       APP_READY_ENTR_L23 | APP_REQ_ENTR_L1;
+	writel(val, rcar->base + PCIEPWRMNGCTRL);
+
+	return 0;
+}
+
 static void rcar_gen4_pcie_phy_reg_update_bits(struct rcar_gen4_pcie *rcar,
 					       u32 offset, u32 mask, u32 val)
 {
@@ -925,6 +1023,13 @@ static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen4_pcie_ep = {
 	.mode = DW_PCIE_EP_TYPE,
 };
 
+static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen5_pcie = {
+	.additional_common_init = rcar_gen5_pcie_additional_common_init,
+	.ltssm_control = rcar_gen5_pcie_ltssm_control,
+	.speed_control = rcar_gen5_pcie_speed_control,
+	.mode = DW_PCIE_RC_TYPE,
+};
+
 static const struct of_device_id rcar_gen4_pcie_of_match[] = {
 	{
 		.compatible = "renesas,r8a779f0-pcie",
@@ -942,6 +1047,10 @@ static const struct of_device_id rcar_gen4_pcie_of_match[] = {
 		.compatible = "renesas,rcar-gen4-pcie-ep",
 		.data = &drvdata_rcar_gen4_pcie_ep,
 	},
+	{
+		.compatible = "renesas,rcar-gen5-pcie4",
+		.data = &drvdata_rcar_gen5_pcie,
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, rcar_gen4_pcie_of_match);
-- 
2.53.0