diff mbox series

[v12,03/11] PCI: kirin: Add support for a PHY layer

Message ID 8a6d353145c0ec169d212094f5d534f93e2597f8.1632814194.git.mchehab+huawei@kernel.org (mailing list archive)
State Superseded
Delegated to: Lorenzo Pieralisi
Headers show
Series Add support for Hikey 970 PCIe | expand

Commit Message

Mauro Carvalho Chehab Sept. 28, 2021, 7:34 a.m. UTC
The pcie-kirin driver contains both PHY and generic PCI driver
on it.

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.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---

To mailbombing on a large number of people, only mailing lists were C/C on the cover.
See [PATCH v12 00/11] at: https://lore.kernel.org/all/cover.1632814194.git.mchehab+huawei@kernel.org/

 drivers/pci/controller/dwc/pcie-kirin.c | 95 +++++++++++++++++++++----
 1 file changed, 80 insertions(+), 15 deletions(-)

Comments

Pali Rohár Oct. 5, 2021, 8:31 p.m. UTC | #1
Hello!

On Tuesday 28 September 2021 09:34:13 Mauro Carvalho Chehab wrote:
> The pcie-kirin driver contains both PHY and generic PCI driver
> on it.
> 
> 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.

I have not looked deeply at it. But is not it really possible to declare
PHY node in DTS file with backward compatible manner? Or cannot Rob help
with it (maybe there was similar issue in past with other driver)?

I was fixing something similar, address space defined in DTS was used by
two HW blocks: clock and UART. And I was able to make both DTS file and
driver backward compatible.
Mauro Carvalho Chehab Oct. 5, 2021, 10:33 p.m. UTC | #2
Hi Pali,

Em Tue, 5 Oct 2021 22:31:48 +0200
Pali Rohár <pali@kernel.org> escreveu:

> Hello!
> 
> On Tuesday 28 September 2021 09:34:13 Mauro Carvalho Chehab wrote:
> > The pcie-kirin driver contains both PHY and generic PCI driver
> > on it.
> > 
> > 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.  
> 
> I have not looked deeply at it. But is not it really possible to declare
> PHY node in DTS file with backward compatible manner? Or cannot Rob help
> with it (maybe there was similar issue in past with other driver)?

It would be possible to split the Kirin 960 PHY into drivers/phy. It is
also possible to hack the phy driver to search for the PHY-specific data
inside the PCI compatible string (I did wrote some patches doing that
and sent as a RFC several months ago), but the problem is that the
PHY driver won't be probed without adding a new compatible inside the
DT schema. By doing that, the schema will be incompatible.

In any case, the patches on this series split all PHY-specific code
inside the driver on a separate part of the source code. Moving it
to a new driver would be easy once someone comes with a solution
to add some new method at the PHY layer that would allow to load a
new module without having a compatible for it.

> I was fixing something similar, address space defined in DTS was used by
> two HW blocks: clock and UART. And I was able to make both DTS file and
> driver backward compatible.

Thanks,
Mauro
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pcie-kirin.c b/drivers/pci/controller/dwc/pcie-kirin.c
index b4063a3434df..31514a5d4bb4 100644
--- a/drivers/pci/controller/dwc/pcie-kirin.c
+++ b/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 = (enum pcie_kirin_phy_type)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;
-
-	ret = hi3660_pcie_phy_init(pdev, kirin_pcie);
-	if (ret)
-		return ret;
+	kirin_pcie->type = phy_type;
 
 	ret = kirin_pcie_get_resource(kirin_pcie, pdev);
 	if (ret)
 		return ret;
 
-	ret = hi3660_pcie_phy_power_on(kirin_pcie);
-	if (ret)
-		return ret;
-
 	platform_set_drvdata(pdev, kirin_pcie);
 
+	ret = kirin_pcie_power_on(pdev, kirin_pcie);
+	if (ret)
+		return ret;
+
 	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,