[PATCH v3 4/6] PCI: dwc: rcar-gen4: Split .start_link into ltssm_control and speed_control

Marek Vasut <[email protected]> Tue, 28 Jul 2026 03:32:37 +0200
Newsgroups org.kernel.vger.linux-renesas-soc,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kernel.vger.linux-pci
Message-ID <[email protected]>
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 <[email protected]>
---
Cc: "Krzysztof WilczyƄski" <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Conor Dooley <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Krzysztof Kozlowski <[email protected]>
Cc: Lorenzo Pieralisi <[email protected]>
Cc: Manivannan Sadhasivam <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Yoshihiro Shimoda <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
V2: No change
V3: No change
---
 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 b39f9bc447afe..ff1969338a276 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -90,6 +90,7 @@ struct rcar_gen4_pcie_drvdata {
 	int (*init)(struct rcar_gen4_pcie *rcar);
 	void (*deinit)(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;
 };
 
@@ -141,20 +142,10 @@ 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
@@ -178,6 +169,24 @@ 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);
@@ -860,6 +869,7 @@ static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie = {
 	.init = rcar_gen4_pcie_common_init,
 	.deinit = rcar_gen4_pcie_common_deinit,
 	.ltssm_control = r8a779f0_pcie_ltssm_control,
+	.speed_control = rcar_gen4_pcie_speed_control,
 	.mode = DW_PCIE_RC_TYPE,
 };
 
@@ -867,6 +877,7 @@ static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie_ep = {
 	.init = rcar_gen4_pcie_common_init,
 	.deinit = rcar_gen4_pcie_common_deinit,
 	.ltssm_control = r8a779f0_pcie_ltssm_control,
+	.speed_control = rcar_gen4_pcie_speed_control,
 	.mode = DW_PCIE_EP_TYPE,
 };
 
@@ -874,6 +885,7 @@ static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen4_pcie = {
 	.init = rcar_gen4_v4h_v4m_pcie_init,
 	.deinit = rcar_gen4_pcie_common_deinit,
 	.ltssm_control = rcar_gen4_pcie_ltssm_control,
+	.speed_control = rcar_gen4_pcie_speed_control,
 	.mode = DW_PCIE_RC_TYPE,
 };
 
@@ -881,6 +893,7 @@ static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen4_pcie_ep = {
 	.init = rcar_gen4_v4h_v4m_pcie_init,
 	.deinit = rcar_gen4_pcie_common_deinit,
 	.ltssm_control = rcar_gen4_pcie_ltssm_control,
+	.speed_control = rcar_gen4_pcie_speed_control,
 	.mode = DW_PCIE_EP_TYPE,
 };
 
-- 
2.53.0