Re: [PATCH v2] PCI: qcom: Add support for modular builds

[Lorenzo Pieralisi <lpieralisi@kernel.org>]

On Tue, Sep 20, 2022 at 10:47:56AM +0200, Johan Hovold wrote:
> Hi Lorenzo,
> 
> On Thu, Jul 21, 2022 at 08:47:20AM +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.
> > 
> > Reviewed-by: Rob Herring <robh@kernel.org>
> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > ---
> > 
> > Changes in v2
> >  - rebase on next-20220720 (adjust context)
> >  - add Rob and Mani's reviewed-by tags
> 
> Have you had a change to look at this one since you got back from
> vacation?
> 
> I believe this should be uncontroversial as we already have other
> modular dwc drivers and there's no mapping of legacy INTx interrupts
> involved.

Sincere apologies for the delay.

I am afraid it does look controversial - I need some time to go through
the full discussion and make up my mind, unfortunately we are late in
the cycle and I am dealing with the patch backlog, I believe this may
end up being a discussion targeting the v6.2 merge window I am afraid.

Lorenzo

> >  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 5ed164c2afa3..d176c635016b 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>
> > @@ -1518,6 +1518,15 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *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,
> >  };
> > @@ -1752,6 +1761,22 @@ 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 },
> > @@ -1771,6 +1796,7 @@ static const struct of_device_id qcom_pcie_match[] = {
> >  	{ .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg },
> >  	{ }
> >  };
> > +MODULE_DEVICE_TABLE(of, qcom_pcie_match);
> >  
> >  static void qcom_fixup_class(struct pci_dev *dev)
> >  {
> > @@ -1786,10 +1812,14 @@ 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");
> 
> Johan