diff mbox series

PCI: qcom: Add support for modular builds

Message ID 20220519094646.23009-1-johan+linaro@kernel.org (mailing list archive)
State New
Headers show
Series PCI: qcom: Add support for modular builds | expand

Commit Message

Johan Hovold May 19, 2022, 9:46 a.m. UTC
Allow the Qualcomm PCIe controller driver to be built as a module, which
is useful for multi-platform kernels as well as during development.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/pci/controller/dwc/Kconfig     |  2 +-
 drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++---
 2 files changed, 34 insertions(+), 4 deletions(-)

Comments

Rob Herring May 26, 2022, 8:53 p.m. UTC | #1
On Thu, May 19, 2022 at 11:46:46AM +0200, Johan Hovold wrote:
> Allow the Qualcomm PCIe controller driver to be built as a module, which
> is useful for multi-platform kernels as well as during development.
> 
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>  drivers/pci/controller/dwc/Kconfig     |  2 +-
>  drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++---
>  2 files changed, 34 insertions(+), 4 deletions(-)

Reviewed-by: Rob Herring <robh@kernel.org>
Johan Hovold June 23, 2022, 11:40 a.m. UTC | #2
On Thu, May 26, 2022 at 03:53:04PM -0500, Rob Herring wrote:
> On Thu, May 19, 2022 at 11:46:46AM +0200, Johan Hovold wrote:
> > Allow the Qualcomm PCIe controller driver to be built as a module, which
> > is useful for multi-platform kernels as well as during development.
> > 
> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > ---
> >  drivers/pci/controller/dwc/Kconfig     |  2 +-
> >  drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++---
> >  2 files changed, 34 insertions(+), 4 deletions(-)
> 
> Reviewed-by: Rob Herring <robh@kernel.org>

Lorenzo, Bjorn H, any comments to this one?

Johan
Bjorn Helgaas June 23, 2022, 3:52 p.m. UTC | #3
On Thu, May 19, 2022 at 11:46:46AM +0200, Johan Hovold wrote:
> Allow the Qualcomm PCIe controller driver to be built as a module, which
> is useful for multi-platform kernels as well as during development.
> 
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>  drivers/pci/controller/dwc/Kconfig     |  2 +-
>  drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++---
>  2 files changed, 34 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> index 62ce3abf0f19..230f56d1a268 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -168,7 +168,7 @@ config PCI_HISI
>  	  Hip05 and Hip06 SoCs
>  
>  config PCIE_QCOM
> -	bool "Qualcomm PCIe controller"
> +	tristate "Qualcomm PCIe controller"
>  	depends on OF && (ARCH_QCOM || COMPILE_TEST)
>  	depends on PCI_MSI_IRQ_DOMAIN
>  	select PCIE_DW_HOST
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 8523b5ef9d16..e25d5c09657c 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -16,7 +16,7 @@
>  #include <linux/io.h>
>  #include <linux/iopoll.h>
>  #include <linux/kernel.h>
> -#include <linux/init.h>
> +#include <linux/module.h>
>  #include <linux/of_device.h>
>  #include <linux/of_gpio.h>
>  #include <linux/pci.h>
> @@ -1425,6 +1425,15 @@ static int qcom_pcie_host_init(struct pcie_port *pp)
>  	return ret;
>  }
>  
> +static void qcom_pcie_host_deinit(struct qcom_pcie *pcie)
> +{
> +	qcom_ep_reset_assert(pcie);
> +	if (pcie->cfg->ops->post_deinit)
> +		pcie->cfg->ops->post_deinit(pcie);
> +	phy_power_off(pcie->phy);
> +	pcie->cfg->ops->deinit(pcie);

These post_deinit/deinit names look backwards.  Why would we call a
"post_deinit()" method *before* the "deinit()" method?  It would make
sense if we called "pre_deinit()" followed by "deinit()".

>  static const struct dw_pcie_host_ops qcom_pcie_dw_ops = {
>  	.host_init = qcom_pcie_host_init,
>  };
> @@ -1651,6 +1660,22 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> +static int qcom_pcie_remove(struct platform_device *pdev)
> +{
> +	struct qcom_pcie *pcie = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +
> +	dw_pcie_host_deinit(&pcie->pci->pp);
> +	qcom_pcie_host_deinit(pcie);
> +
> +	phy_exit(pcie->phy);
> +
> +	pm_runtime_put_sync(dev);
> +	pm_runtime_disable(dev);

Why is this not more symmetric with qcom_pcie_probe()?  Maybe struct
dw_pcie_host_ops needs a new .host_deinit() pointer that would be
called from dw_pcie_host_deinit()?

In the probe path, we have this:

  qcom_pcie_probe
    pm_runtime_enable
    pm_runtime_get_sync
    phy_init(pcie->phy)
    dw_pcie_host_init
      pp->ops->host_init
        qcom_pcie_host_init             # .host_init()
          pcie->cfg->ops->init(pcie)
          phy_power_on(pcie->phy)
          pcie->cfg->ops->post_init(pcie)
          qcom_ep_reset_deassert(pcie)

The remove path does do things in the opposite order, which makes
sense, but the call to qcom_pcie_host_deinit() breaks the symmetry:

  qcom_pcie_remove
    dw_pcie_host_deinit
    qcom_pcie_host_deinit
      qcom_ep_reset_assert
      pcie->cfg->ops->post_deinit
      phy_power_off(pcie->phy)
      pcie->cfg->ops->deinit
    phy_exit(pcie->phy)
    pm_runtime_put_sync
    pm_runtime_disable

> +	return 0;
> +}
> +
>  static const struct of_device_id qcom_pcie_match[] = {
>  	{ .compatible = "qcom,pcie-apq8084", .data = &apq8084_cfg },
>  	{ .compatible = "qcom,pcie-ipq8064", .data = &ipq8064_cfg },
> @@ -1669,6 +1694,7 @@ static const struct of_device_id qcom_pcie_match[] = {
>  	{ .compatible = "qcom,pcie-sc7280", .data = &sc7280_cfg },
>  	{ }
>  };
> +MODULE_DEVICE_TABLE(of, qcom_pcie_match);
>  
>  static void qcom_fixup_class(struct pci_dev *dev)
>  {
> @@ -1684,10 +1710,14 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1001, qcom_fixup_class);
>  
>  static struct platform_driver qcom_pcie_driver = {
>  	.probe = qcom_pcie_probe,
> +	.remove = qcom_pcie_remove,
>  	.driver = {
>  		.name = "qcom-pcie",
> -		.suppress_bind_attrs = true,
>  		.of_match_table = qcom_pcie_match,
>  	},
>  };
> -builtin_platform_driver(qcom_pcie_driver);
> +module_platform_driver(qcom_pcie_driver);
> +
> +MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>");
> +MODULE_DESCRIPTION("Qualcomm PCIe root complex driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.35.1
>
Johan Hovold June 27, 2022, 7:31 a.m. UTC | #4
On Thu, Jun 23, 2022 at 10:52:13AM -0500, Bjorn Helgaas wrote:
> On Thu, May 19, 2022 at 11:46:46AM +0200, Johan Hovold wrote:
> > Allow the Qualcomm PCIe controller driver to be built as a module, which
> > is useful for multi-platform kernels as well as during development.
> > 
> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > ---

> > +static void qcom_pcie_host_deinit(struct qcom_pcie *pcie)
> > +{
> > +	qcom_ep_reset_assert(pcie);
> > +	if (pcie->cfg->ops->post_deinit)
> > +		pcie->cfg->ops->post_deinit(pcie);
> > +	phy_power_off(pcie->phy);
> > +	pcie->cfg->ops->deinit(pcie);
> 
> These post_deinit/deinit names look backwards.  Why would we call a
> "post_deinit()" method *before* the "deinit()" method?  It would make
> sense if we called "pre_deinit()" followed by "deinit()".

Yeah, that annoys me as well, but those are the names the driver
currently use.

I considered renaming the deinit callback but instead sent a follow up
patch to remove both of these callbacks now that the pipe clock rework
that depends on them has been merged, but seems like the post_init one
will be needed for the DBI accesses.

I can respin the above mentioned patch to drop or or rename the badly
named one when things settle down a bit.

> >  static const struct dw_pcie_host_ops qcom_pcie_dw_ops = {
> >  	.host_init = qcom_pcie_host_init,
> >  };
> > @@ -1651,6 +1660,22 @@ static int qcom_pcie_probe(struct platform_device *pdev)
> >  	return ret;
> >  }
> >  
> > +static int qcom_pcie_remove(struct platform_device *pdev)
> > +{
> > +	struct qcom_pcie *pcie = platform_get_drvdata(pdev);
> > +	struct device *dev = &pdev->dev;
> > +
> > +	dw_pcie_host_deinit(&pcie->pci->pp);
> > +	qcom_pcie_host_deinit(pcie);
> > +
> > +	phy_exit(pcie->phy);
> > +
> > +	pm_runtime_put_sync(dev);
> > +	pm_runtime_disable(dev);
> 
> Why is this not more symmetric with qcom_pcie_probe()?  Maybe struct
> dw_pcie_host_ops needs a new .host_deinit() pointer that would be
> called from dw_pcie_host_deinit()?

Yeah, I considered that too but decided it's not needed to implement
modular builds for this driver. Instead I did the ground work by adding
a deinit helper function so that it's easier to track any additions to
the host_init() callback and which can later be called by core if
someone decides to clean up core and add a deinit callback.

Looks like someone just posted something along these lines, but this
would conflict with the split MSI series which is otherwise ready to be
merged:

	https://lore.kernel.org/r/20220624143947.8991-9-Sergey.Semin@baikalelectronics.ru

Also note that there are other drivers that implement remove() without
this callback already today.

> In the probe path, we have this:
> 
>   qcom_pcie_probe
>     pm_runtime_enable
>     pm_runtime_get_sync
>     phy_init(pcie->phy)
>     dw_pcie_host_init
>       pp->ops->host_init
>         qcom_pcie_host_init             # .host_init()
>           pcie->cfg->ops->init(pcie)
>           phy_power_on(pcie->phy)
>           pcie->cfg->ops->post_init(pcie)
>           qcom_ep_reset_deassert(pcie)
> 
> The remove path does do things in the opposite order, which makes
> sense, but the call to qcom_pcie_host_deinit() breaks the symmetry:
> 
>   qcom_pcie_remove
>     dw_pcie_host_deinit
>     qcom_pcie_host_deinit
>       qcom_ep_reset_assert
>       pcie->cfg->ops->post_deinit
>       phy_power_off(pcie->phy)
>       pcie->cfg->ops->deinit
>     phy_exit(pcie->phy)
>     pm_runtime_put_sync
>     pm_runtime_disable

Yeah, I didn't want to go rewrite core just for this basic driver
functionality. Especially with so many things already in flux.

As mentioned above, everything is instead prepared to move over to such
a callback if and when it materialises.

Johan
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 62ce3abf0f19..230f56d1a268 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -168,7 +168,7 @@  config PCI_HISI
 	  Hip05 and Hip06 SoCs
 
 config PCIE_QCOM
-	bool "Qualcomm PCIe controller"
+	tristate "Qualcomm PCIe controller"
 	depends on OF && (ARCH_QCOM || COMPILE_TEST)
 	depends on PCI_MSI_IRQ_DOMAIN
 	select PCIE_DW_HOST
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 8523b5ef9d16..e25d5c09657c 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -16,7 +16,7 @@ 
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
-#include <linux/init.h>
+#include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/of_gpio.h>
 #include <linux/pci.h>
@@ -1425,6 +1425,15 @@  static int qcom_pcie_host_init(struct pcie_port *pp)
 	return ret;
 }
 
+static void qcom_pcie_host_deinit(struct qcom_pcie *pcie)
+{
+	qcom_ep_reset_assert(pcie);
+	if (pcie->cfg->ops->post_deinit)
+		pcie->cfg->ops->post_deinit(pcie);
+	phy_power_off(pcie->phy);
+	pcie->cfg->ops->deinit(pcie);
+}
+
 static const struct dw_pcie_host_ops qcom_pcie_dw_ops = {
 	.host_init = qcom_pcie_host_init,
 };
@@ -1651,6 +1660,22 @@  static int qcom_pcie_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static int qcom_pcie_remove(struct platform_device *pdev)
+{
+	struct qcom_pcie *pcie = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	dw_pcie_host_deinit(&pcie->pci->pp);
+	qcom_pcie_host_deinit(pcie);
+
+	phy_exit(pcie->phy);
+
+	pm_runtime_put_sync(dev);
+	pm_runtime_disable(dev);
+
+	return 0;
+}
+
 static const struct of_device_id qcom_pcie_match[] = {
 	{ .compatible = "qcom,pcie-apq8084", .data = &apq8084_cfg },
 	{ .compatible = "qcom,pcie-ipq8064", .data = &ipq8064_cfg },
@@ -1669,6 +1694,7 @@  static const struct of_device_id qcom_pcie_match[] = {
 	{ .compatible = "qcom,pcie-sc7280", .data = &sc7280_cfg },
 	{ }
 };
+MODULE_DEVICE_TABLE(of, qcom_pcie_match);
 
 static void qcom_fixup_class(struct pci_dev *dev)
 {
@@ -1684,10 +1710,14 @@  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1001, qcom_fixup_class);
 
 static struct platform_driver qcom_pcie_driver = {
 	.probe = qcom_pcie_probe,
+	.remove = qcom_pcie_remove,
 	.driver = {
 		.name = "qcom-pcie",
-		.suppress_bind_attrs = true,
 		.of_match_table = qcom_pcie_match,
 	},
 };
-builtin_platform_driver(qcom_pcie_driver);
+module_platform_driver(qcom_pcie_driver);
+
+MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>");
+MODULE_DESCRIPTION("Qualcomm PCIe root complex driver");
+MODULE_LICENSE("GPL");