[PATCH v7 5/7] PCI: rcar-gen4: Add .ltssm_enable() for other SoC support

[Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>]

This driver can reuse other R-Car Gen4 SoCs support like r8a779g0 and
r8a779h0. However, r8a779g0 and r8a779h0 require other initializing
settings that differ than r8a779f0. So, add a new function pointer
.ltssm_enable() for it.

After applied this patch, probing SoCs by rcar_gen4_pcie_of_match[]
will be changed like below:

- r8a779f0 as "renesas,r8a779f0-pcie" and "renesas,r8a779f0-pcie-ep"

Existing dts files have the compatible above. So, no behavior changes.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
 drivers/pci/controller/dwc/pcie-rcar-gen4.c | 41 ++++++++++++++++++---
 1 file changed, 36 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index 3da0a844e1b6..980a916933d6 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -48,7 +48,9 @@
 #define RCAR_GEN4_PCIE_EP_FUNC_DBI_OFFSET	0x1000
 #define RCAR_GEN4_PCIE_EP_FUNC_DBI2_OFFSET	0x800
 
+struct rcar_gen4_pcie;
 struct rcar_gen4_pcie_drvdata {
+	int (*ltssm_enable)(struct rcar_gen4_pcie *rcar);
 	enum dw_pcie_device_mode mode;
 };
 
@@ -61,8 +63,8 @@ struct rcar_gen4_pcie {
 #define to_rcar_gen4_pcie(_dw)	container_of(_dw, struct rcar_gen4_pcie, dw)
 
 /* Common */
-static void rcar_gen4_pcie_ltssm_enable(struct rcar_gen4_pcie *rcar,
-					bool enable)
+static void rcar_gen4_pcie_ltssm_control(struct rcar_gen4_pcie *rcar,
+					 bool enable)
 {
 	u32 val;
 
@@ -127,9 +129,13 @@ static int rcar_gen4_pcie_speed_change(struct dw_pcie *dw)
 static int rcar_gen4_pcie_start_link(struct dw_pcie *dw)
 {
 	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
-	int i, changes;
+	int i, changes, ret;
 
-	rcar_gen4_pcie_ltssm_enable(rcar, true);
+	if (rcar->drvdata->ltssm_enable) {
+		ret = rcar->drvdata->ltssm_enable(rcar);
+		if (ret)
+			return ret;
+	}
 
 	/*
 	 * Require direct speed change with retrying here if the link_gen is
@@ -157,7 +163,7 @@ static void rcar_gen4_pcie_stop_link(struct dw_pcie *dw)
 {
 	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
 
-	rcar_gen4_pcie_ltssm_enable(rcar, false);
+	rcar_gen4_pcie_ltssm_control(rcar, false);
 }
 
 static int rcar_gen4_pcie_common_init(struct rcar_gen4_pcie *rcar)
@@ -504,6 +510,23 @@ static void rcar_gen4_pcie_remove(struct platform_device *pdev)
 	rcar_gen4_pcie_unprepare(rcar);
 }
 
+static int r8a779f0_pcie_ltssm_enable(struct rcar_gen4_pcie *rcar)
+{
+	rcar_gen4_pcie_ltssm_control(rcar, true);
+
+	return 0;
+}
+
+static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie = {
+	.ltssm_enable = r8a779f0_pcie_ltssm_enable,
+	.mode = DW_PCIE_RC_TYPE,
+};
+
+static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie_ep = {
+	.ltssm_enable = r8a779f0_pcie_ltssm_enable,
+	.mode = DW_PCIE_EP_TYPE,
+};
+
 static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen4_pcie = {
 	.mode = DW_PCIE_RC_TYPE,
 };
@@ -513,6 +536,14 @@ static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen4_pcie_ep = {
 };
 
 static const struct of_device_id rcar_gen4_pcie_of_match[] = {
+	{
+		.compatible = "renesas,r8a779f0-pcie",
+		.data = &drvdata_r8a779f0_pcie,
+	},
+	{
+		.compatible = "renesas,r8a779f0-pcie-ep",
+		.data = &drvdata_r8a779f0_pcie_ep,
+	},
 	{
 		.compatible = "renesas,rcar-gen4-pcie",
 		.data = &drvdata_rcar_gen4_pcie,
-- 
2.25.1