PCI: kirin: Add support for a PHY layer

The pcie-kirin driver contains both PHY and generic PCI driver.

The best would be, instead, to support a PCI PHY driver, making the driver
more generic.

However, it is too late to remove the Kirin 960 PHY, as a change like that
would make the DT schema incompatible with past versions.

So, add support for an external PHY driver without removing the existing
Kirin 960 PHY from it.

Link: https://lore.kernel.org/r/f38361df2e9d0dc5a38ff942b631f7fef64cdc12.1634812676.git.mchehab+huawei@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Xiaowei Song <songxiaowei@hisilicon.com>

drivers/pci/controller/dwc/pcie-kirin.c

@@ -8,16 +8,18 @@
  * Author: Xiaowei Song <songxiaowei@huawei.com>
  */
 
-#include <linux/compiler.h>
 #include <linux/clk.h>
+#include <linux/compiler.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/mfd/syscon.h>
 #include <linux/of_address.h>
+#include <linux/of_device.h>
 #include <linux/of_gpio.h>
 #include <linux/of_pci.h>
+#include <linux/phy/phy.h>
 #include <linux/pci.h>
 #include <linux/pci_regs.h>
 #include <linux/platform_device.h>
@@ -50,11 +52,18 @@
 #define PCIE_DEBOUNCE_PARAM	0xF0F400
 #define PCIE_OE_BYPASS		(0x3 << 28)
 
+enum pcie_kirin_phy_type {
+	PCIE_KIRIN_INTERNAL_PHY,
+	PCIE_KIRIN_EXTERNAL_PHY
+};
+
 struct kirin_pcie {
+	enum pcie_kirin_phy_type	type;
+
 	struct dw_pcie	*pci;
 	struct phy	*phy;
 	void __iomem	*apb_base;
-	void		*phy_priv;	/* Needed for Kirin 960 PHY */
+	void		*phy_priv;	/* only for PCIE_KIRIN_INTERNAL_PHY */
 };
 
 /*
@@ -476,8 +485,63 @@ static const struct dw_pcie_host_ops kirin_pcie_host_ops = {
 	.host_init = kirin_pcie_host_init,
 };
 
+static int kirin_pcie_power_on(struct platform_device *pdev,
+			       struct kirin_pcie *kirin_pcie)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	if (kirin_pcie->type == PCIE_KIRIN_INTERNAL_PHY) {
+		ret = hi3660_pcie_phy_init(pdev, kirin_pcie);
+		if (ret)
+			return ret;
+
+		return hi3660_pcie_phy_power_on(kirin_pcie);
+	}
+
+	kirin_pcie->phy = devm_of_phy_get(dev, dev->of_node, NULL);
+	if (IS_ERR(kirin_pcie->phy))
+		return PTR_ERR(kirin_pcie->phy);
+
+	ret = phy_init(kirin_pcie->phy);
+	if (ret)
+		goto err;
+
+	ret = phy_power_on(kirin_pcie->phy);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	phy_exit(kirin_pcie->phy);
+	return ret;
+}
+
+static int __exit kirin_pcie_remove(struct platform_device *pdev)
+{
+	struct kirin_pcie *kirin_pcie = platform_get_drvdata(pdev);
+
+	if (kirin_pcie->type == PCIE_KIRIN_INTERNAL_PHY)
+		return 0;
+
+	phy_power_off(kirin_pcie->phy);
+	phy_exit(kirin_pcie->phy);
+
+	return 0;
+}
+
+static const struct of_device_id kirin_pcie_match[] = {
+	{
+		.compatible = "hisilicon,kirin960-pcie",
+		.data = (void *)PCIE_KIRIN_INTERNAL_PHY
+	},
+	{},
+};
+
 static int kirin_pcie_probe(struct platform_device *pdev)
 {
+	enum pcie_kirin_phy_type phy_type;
+	const struct of_device_id *of_id;
 	struct device *dev = &pdev->dev;
 	struct kirin_pcie *kirin_pcie;
 	struct dw_pcie *pci;
@@ -488,6 +552,14 @@ static int kirin_pcie_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	of_id = of_match_device(kirin_pcie_match, dev);
+	if (!of_id) {
+		dev_err(dev, "OF data missing\n");
+		return -EINVAL;
+	}
+
+	phy_type = (long)of_id->data;
+
 	kirin_pcie = devm_kzalloc(dev, sizeof(struct kirin_pcie), GFP_KERNEL);
 	if (!kirin_pcie)
 		return -ENOMEM;
@@ -500,31 +572,24 @@ static int kirin_pcie_probe(struct platform_device *pdev)
 	pci->ops = &kirin_dw_pcie_ops;
 	pci->pp.ops = &kirin_pcie_host_ops;
 	kirin_pcie->pci = pci;
-
+	kirin_pcie->type = phy_type;
-	ret = hi3660_pcie_phy_init(pdev, kirin_pcie);
-	if (ret)
-		return ret;
 
 	ret = kirin_pcie_get_resource(kirin_pcie, pdev);
 	if (ret)
 		return ret;
 
-	ret = hi3660_pcie_phy_power_on(kirin_pcie);
+	platform_set_drvdata(pdev, kirin_pcie);
+
+	ret = kirin_pcie_power_on(pdev, kirin_pcie);
 	if (ret)
 		return ret;
 
-	platform_set_drvdata(pdev, kirin_pcie);
-
 	return dw_pcie_host_init(&pci->pp);
 }
 
-static const struct of_device_id kirin_pcie_match[] = {
-	{ .compatible = "hisilicon,kirin960-pcie" },
-	{},
-};
-
 static struct platform_driver kirin_pcie_driver = {
 	.probe			= kirin_pcie_probe,
+	.remove	        	= __exit_p(kirin_pcie_remove),
 	.driver			= {
 		.name			= "kirin-pcie",
 		.of_match_table		= kirin_pcie_match,