PCI: rcar-gen4: Add .ltssm_control() for other SoC support

Sequence for controlling the LTSSM state machine is going to change
for SoCs like r8a779f0. Move the LTSSM code to a new callback
ltssm_control() and populate it for each SoCs.

This also warrants the addition of new compatibles for r8a779g0 and
r8a779h0. But since they are already part of the DT binding, it won't
make any difference.

Link: https://lore.kernel.org/linux-pci/[email protected]
Signed-off-by: Yoshihiro Shimoda <[email protected]>
Signed-off-by: Krzysztof Wilczyński <[email protected]>
Reviewed-by: Manivannan Sadhasivam <[email protected]>

Author: shimoday

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_control)(struct rcar_gen4_pcie *rcar, bool enable);
 	enum dw_pcie_device_mode mode;
 };
 
@@ -61,27 +63,6 @@ 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)
-{
-	u32 val;
-
-	val = readl(rcar->base + PCIERSTCTRL1);
-	if (enable) {
-		val |= APP_LTSSM_ENABLE;
-		val &= ~APP_HOLD_PHY_RST;
-	} else {
-		/*
-		 * Since the datasheet of R-Car doesn't mention how to assert
-		 * the APP_HOLD_PHY_RST, don't assert it again. Otherwise,
-		 * hang-up issue happened in the dw_edma_core_off() when
-		 * the controller didn't detect a PCI device.
-		 */
-		val &= ~APP_LTSSM_ENABLE;
-	}
-	writel(val, rcar->base + PCIERSTCTRL1);
-}
-
 static int rcar_gen4_pcie_link_up(struct dw_pcie *dw)
 {
 	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
@@ -127,9 +108,13 @@ 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_control) {
+		ret = rcar->drvdata->ltssm_control(rcar, true);
+		if (ret)
+			return ret;
+	}
 
 	/*
 	 * Require direct speed change with retrying here if the link_gen is
@@ -157,7 +142,8 @@ 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);
+	if (rcar->drvdata->ltssm_control)
+		rcar->drvdata->ltssm_control(rcar, false);
 }
 
 static int rcar_gen4_pcie_common_init(struct rcar_gen4_pcie *rcar)
@@ -520,6 +506,38 @@ static void rcar_gen4_pcie_remove(struct platform_device *pdev)
 	rcar_gen4_pcie_unprepare(rcar);
 }
 
+static int r8a779f0_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 {
+		/*
+		 * Since the datasheet of R-Car doesn't mention how to assert
+		 * the APP_HOLD_PHY_RST, don't assert it again. Otherwise,
+		 * hang-up issue happened in the dw_edma_core_off() when
+		 * the controller didn't detect a PCI device.
+		 */
+		val &= ~APP_LTSSM_ENABLE;
+	}
+	writel(val, rcar->base + PCIERSTCTRL1);
+
+	return 0;
+}
+
+static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie = {
+	.ltssm_control = r8a779f0_pcie_ltssm_control,
+	.mode = DW_PCIE_RC_TYPE,
+};
+
+static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie_ep = {
+	.ltssm_control = r8a779f0_pcie_ltssm_control,
+	.mode = DW_PCIE_EP_TYPE,
+};
+
 static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen4_pcie = {
 	.mode = DW_PCIE_RC_TYPE,
 };
@@ -529,6 +547,14 @@ 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,