PCI: dw-rockchip: Refactor the driver to prepare for EP mode

Refactor the driver to prepare for EP mode.

Add of-match data to the existing compatible, and explicitly define it as
DW_PCIE_RC_TYPE. This way, we will be able to add EP mode in a follow-up
commit in a much less intrusive way, which makes the follow-up commit much
easier to review.

No functional change intended.

Link: https://lore.kernel.org/linux-pci/20240607-rockchip-pcie-ep-v1-v5-9-0a042d6b0049@kernel.orgSigned-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

drivers/pci/controller/dwc/pcie-dw-rockchip.c

@@ -49,15 +49,20 @@
 #define PCIE_LTSSM_STATUS_MASK		GENMASK(5, 0)
 
 struct rockchip_pcie {
-	struct dw_pcie			pci;
-	void __iomem			*apb_base;
-	struct phy			*phy;
-	struct clk_bulk_data		*clks;
-	unsigned int			clk_cnt;
-	struct reset_control		*rst;
-	struct gpio_desc		*rst_gpio;
-	struct regulator                *vpcie3v3;
-	struct irq_domain		*irq_domain;
+	struct dw_pcie pci;
+	void __iomem *apb_base;
+	struct phy *phy;
+	struct clk_bulk_data *clks;
+	unsigned int clk_cnt;
+	struct reset_control *rst;
+	struct gpio_desc *rst_gpio;
+	struct regulator *vpcie3v3;
+	struct irq_domain *irq_domain;
+	const struct rockchip_pcie_of_data *data;
+};
+
+struct rockchip_pcie_of_data {
+	enum dw_pcie_device_mode mode;
 };
 
 static int rockchip_pcie_readl_apb(struct rockchip_pcie *rockchip, u32 reg)
@@ -195,7 +200,6 @@ static int rockchip_pcie_host_init(struct dw_pcie_rp *pp)
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
 	struct device *dev = rockchip->pci.dev;
-	u32 val = HIWORD_UPDATE_BIT(PCIE_LTSSM_ENABLE_ENHANCE);
 	int irq, ret;
 
 	irq = of_irq_get_byname(dev->of_node, "legacy");
@@ -209,12 +213,6 @@ static int rockchip_pcie_host_init(struct dw_pcie_rp *pp)
 	irq_set_chained_handler_and_data(irq, rockchip_pcie_intx_handler,
 					 rockchip);
 
-	/* LTSSM enable control mode */
-	rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);
-
-	rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_RC_MODE,
-				 PCIE_CLIENT_GENERAL_CONTROL);
-
 	return 0;
 }
 
@@ -294,13 +292,35 @@ static const struct dw_pcie_ops dw_pcie_ops = {
 	.start_link = rockchip_pcie_start_link,
 };
 
+static int rockchip_pcie_configure_rc(struct rockchip_pcie *rockchip)
+{
+	struct dw_pcie_rp *pp;
+	u32 val;
+
+	/* LTSSM enable control mode */
+	val = HIWORD_UPDATE_BIT(PCIE_LTSSM_ENABLE_ENHANCE);
+	rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);
+
+	rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_RC_MODE,
+				 PCIE_CLIENT_GENERAL_CONTROL);
+
+	pp = &rockchip->pci.pp;
+	pp->ops = &rockchip_pcie_host_ops;
+
+	return dw_pcie_host_init(pp);
+}
+
 static int rockchip_pcie_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct rockchip_pcie *rockchip;
-	struct dw_pcie_rp *pp;
+	const struct rockchip_pcie_of_data *data;
 	int ret;
 
+	data = of_device_get_match_data(dev);
+	if (!data)
+		return -EINVAL;
+
 	rockchip = devm_kzalloc(dev, sizeof(*rockchip), GFP_KERNEL);
 	if (!rockchip)
 		return -ENOMEM;
@@ -309,9 +329,7 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
 
 	rockchip->pci.dev = dev;
 	rockchip->pci.ops = &dw_pcie_ops;
-
-	pp = &rockchip->pci.pp;
-	pp->ops = &rockchip_pcie_host_ops;
+	rockchip->data = data;
 
 	ret = rockchip_pcie_resource_get(pdev, rockchip);
 	if (ret)
@@ -347,10 +365,21 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
 	if (ret)
 		goto deinit_phy;
 
-	ret = dw_pcie_host_init(pp);
-	if (!ret)
-		return 0;
+	switch (data->mode) {
+	case DW_PCIE_RC_TYPE:
+		ret = rockchip_pcie_configure_rc(rockchip);
+		if (ret)
+			goto deinit_clk;
+		break;
+	default:
+		dev_err(dev, "INVALID device type %d\n", data->mode);
+		ret = -EINVAL;
+		goto deinit_clk;
+	}
+
+	return 0;
 
+deinit_clk:
 	clk_bulk_disable_unprepare(rockchip->clk_cnt, rockchip->clks);
 deinit_phy:
 	rockchip_pcie_phy_deinit(rockchip);
@@ -361,8 +390,15 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static const struct rockchip_pcie_of_data rockchip_pcie_rc_of_data_rk3568 = {
+	.mode = DW_PCIE_RC_TYPE,
+};
+
 static const struct of_device_id rockchip_pcie_of_match[] = {
-	{ .compatible = "rockchip,rk3568-pcie", },
+	{
+		.compatible = "rockchip,rk3568-pcie",
+		.data = &rockchip_pcie_rc_of_data_rk3568,
+	},
 	{},
 };