PCI: rcar-gen4: Add .speed_control() callback

Introduce new rcar_gen4_pcie_drvdata->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 work for R-Car Gen5 support, where the .speed_control()
implementation is different.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
[mani: commit log]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260921202823.72620-5-marek.vasut+renesas@mailbox.org

1 files 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 04871ac11c34..c768a9c7b3b7 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);
@@ -916,6 +925,7 @@ 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,
 };
 
@@ -923,6 +933,7 @@ 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,
 };
 
@@ -930,6 +941,7 @@ 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,
 };
 
@@ -937,6 +949,7 @@ 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,
 };