RE: [PATCH v19 17/19] PCI: rcar-gen4-ep: Add R-Car Gen4 PCIe Endpoint support

[Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>]

Hello Serge,

> From: Serge Semin, Sent: Wednesday, August 23, 2023 9:03 PM
> 
> On Wed, Aug 23, 2023 at 06:11:51PM +0900, Yoshihiro Shimoda wrote:
> > Add R-Car Gen4 PCIe Endpoint support. This controller is based on
> > Synopsys DesignWare PCIe.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > ---
> >  drivers/pci/controller/dwc/Kconfig            |  10 +
> >  drivers/pci/controller/dwc/Makefile           |   2 +
> >  .../controller/dwc/pcie-rcar-gen4-ep-drv.c    | 178 ++++++++++++++++++
> >  3 files changed, 190 insertions(+)
> >  create mode 100644 drivers/pci/controller/dwc/pcie-rcar-gen4-ep-drv.c
> >
> > diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> > index 3884a67e4d56..65a7c56e64bd 100644
> > --- a/drivers/pci/controller/dwc/Kconfig
> > +++ b/drivers/pci/controller/dwc/Kconfig
> > @@ -425,4 +425,14 @@ config PCIE_RCAR_GEN4
> >  	  To compile this driver as a module, choose M here: the module will be
> >  	  called pcie-rcar-gen4-host.ko. This uses the DesignWare core.
> >
> > +config PCIE_RCAR_GEN4_EP
> > +	tristate "Renesas R-Car Gen4 PCIe Endpoint controller"
> > +	depends on ARCH_RENESAS || COMPILE_TEST
> > +	depends on PCI_ENDPOINT
> > +	select PCIE_DW_EP
> > +	help
> > +	  Say Y here if you want PCIe endpoint controller support on R-Car Gen4
> > +	  SoCs. To compile this driver as a module, choose M here: the module
> > +	  will be called pcie-rcar-gen4-ep.ko. This uses the DesignWare core.
> > +
> >  endmenu
> > diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
> > index ab2c6bc16216..4d53d660e4fe 100644
> > --- a/drivers/pci/controller/dwc/Makefile
> > +++ b/drivers/pci/controller/dwc/Makefile
> > @@ -28,6 +28,8 @@ obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
> >  obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o
> >  pcie-rcar-gen4-host-objs := pcie-rcar-gen4.o pcie-rcar-gen4-host-drv.o
> >  obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4-host.o
> > +pcie-rcar-gen4-ep-objs := pcie-rcar-gen4.o pcie-rcar-gen4-ep-drv.o
> > +obj-$(CONFIG_PCIE_RCAR_GEN4_EP) += pcie-rcar-gen4-ep.o
> >
> >  # The following drivers are for devices that use the generic ACPI
> >  # pci_root.c driver but don't support standard ECAM config access.
> > diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4-ep-drv.c b/drivers/pci/controller/dwc/pcie-rcar-gen4-ep-drv.c
> > new file mode 100644
> > index 000000000000..71f496ba0eeb
> > --- /dev/null
> > +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4-ep-drv.c
> > @@ -0,0 +1,178 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * PCIe Endpoint driver for Renesas R-Car Gen4 Series SoCs
> > + * Copyright (C) 2022-2023 Renesas Electronics Corporation
> > + */
> > +
> > +#include <linux/interrupt.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/pci.h>
> > +#include <linux/platform_device.h>
> > +
> > +#include "pcie-rcar-gen4.h"
> > +#include "pcie-designware.h"
> > +
> > +#define RCAR_GEN4_PCIE_EP_FUNC_DBI_OFFSET	0x1000
> > +#define RCAR_GEN4_PCIE_EP_FUNC_DBI2_OFFSET	0x800
> > +
> > +static void rcar_gen4_pcie_ep_pre_init(struct dw_pcie_ep *ep)
> > +{
> > +	struct dw_pcie *dw = to_dw_pcie_from_ep(ep);
> > +	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
> > +	int ret;
> > +
> 
> > +	ret = clk_bulk_prepare_enable(DW_PCIE_NUM_CORE_CLKS, dw->core_clks);
> > +	if (ret) {
> > +		dev_err(dw->dev, "Failed to enable ref clocks\n");
> > +		return;
> > +	}
> > +
> > +	rcar_gen4_pcie_common_init(rcar);
> 
> The same note as to the previous patch. The clk_bulk_prepare_enable()
> method invocation can be moved to rcar_gen4_pcie_common_init().

I got it.

> > +
> > +	writel(PCIEDMAINTSTSEN_INIT, rcar->base + PCIEDMAINTSTSEN);
> > +}
> > +
> > +static void rcar_gen4_pcie_ep_init(struct dw_pcie_ep *ep)
> > +{
> > +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> > +	enum pci_barno bar;
> > +
> > +	for (bar = 0; bar < PCI_STD_NUM_BARS; bar++)
> > +		dw_pcie_ep_reset_bar(pci, bar);
> > +}
> > +
> > +static void rcar_gen4_pcie_ep_deinit(struct dw_pcie_ep *ep)
> > +{
> > +	struct dw_pcie *dw = to_dw_pcie_from_ep(ep);
> > +	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
> > +
> > +	writel(0, rcar->base + PCIEDMAINTSTSEN);
> 
> > +	rcar_gen4_pcie_common_deinit(rcar);
> > +	clk_bulk_disable_unprepare(DW_PCIE_NUM_CORE_CLKS, dw->core_clks);
> 
> and clk_bulk_disable_unprepare() - to rcar_gen4_pcie_common_deinit().
> 
> With the above notes fixed feel free to add:
> 
> Reviewed-by: Serge Semin <fancer.lancer@gmail.com>

Thank you very much for your review!

Best regards,
Yoshihiro Shimoda

> -Serge(y)
> 
> > +}
> > +
> > +static int rcar_gen4_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
> > +				       unsigned int type, u16 interrupt_num)
> > +{
> > +	struct dw_pcie *dw = to_dw_pcie_from_ep(ep);
> > +
> > +	switch (type) {
> > +	case PCI_IRQ_LEGACY:
> > +		return dw_pcie_ep_raise_legacy_irq(ep, func_no);
> > +	case PCI_IRQ_MSI:
> > +		return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
> > +	default:
> > +		dev_err(dw->dev, "Unknown IRQ type\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct pci_epc_features rcar_gen4_pcie_epc_features = {
> > +	.linkup_notifier = false,
> > +	.msi_capable = true,
> > +	.msix_capable = false,
> > +	.reserved_bar = 1 << BAR_1 | 1 << BAR_3 | 1 << BAR_5,
> > +	.align = SZ_1M,
> > +};
> > +
> > +static const struct pci_epc_features*
> > +rcar_gen4_pcie_ep_get_features(struct dw_pcie_ep *ep)
> > +{
> > +	return &rcar_gen4_pcie_epc_features;
> > +}
> > +
> > +static unsigned int rcar_gen4_pcie_ep_func_conf_select(struct dw_pcie_ep *ep,
> > +						       u8 func_no)
> > +{
> > +	return func_no * RCAR_GEN4_PCIE_EP_FUNC_DBI_OFFSET;
> > +}
> > +
> > +static unsigned int rcar_gen4_pcie_ep_get_dbi2_offset(struct dw_pcie_ep *ep,
> > +						      u8 func_no)
> > +{
> > +	return func_no * RCAR_GEN4_PCIE_EP_FUNC_DBI2_OFFSET;
> > +}
> > +
> > +static const struct dw_pcie_ep_ops pcie_ep_ops = {
> > +	.pre_init = rcar_gen4_pcie_ep_pre_init,
> > +	.ep_init = rcar_gen4_pcie_ep_init,
> > +	.deinit = rcar_gen4_pcie_ep_deinit,
> > +	.raise_irq = rcar_gen4_pcie_ep_raise_irq,
> > +	.get_features = rcar_gen4_pcie_ep_get_features,
> > +	.func_conf_select = rcar_gen4_pcie_ep_func_conf_select,
> > +	.get_dbi2_offset = rcar_gen4_pcie_ep_get_dbi2_offset,
> > +};
> > +
> > +static int rcar_gen4_add_pcie_ep(struct rcar_gen4_pcie *rcar)
> > +{
> > +	struct dw_pcie_ep *ep = &rcar->dw.ep;
> > +
> > +	rcar->mode = DW_PCIE_EP_TYPE;
> > +	ep->ops = &pcie_ep_ops;
> > +
> > +	return dw_pcie_ep_init(ep);
> > +}
> > +
> > +static void rcar_gen4_remove_pcie_ep(struct rcar_gen4_pcie *rcar)
> > +{
> > +	dw_pcie_ep_exit(&rcar->dw.ep);
> > +}
> > +
> > +static int rcar_gen4_pcie_ep_probe(struct platform_device *pdev)
> > +{
> > +	struct rcar_gen4_pcie *rcar;
> > +	int err;
> > +
> > +	rcar = rcar_gen4_pcie_devm_alloc(pdev);
> > +	if (IS_ERR(rcar))
> > +		return PTR_ERR(rcar);
> > +
> > +	err = rcar_gen4_pcie_get_resources(rcar);
> > +	if (err)
> > +		return err;
> > +
> > +	err = rcar_gen4_pcie_prepare(rcar);
> > +	if (err)
> > +		return err;
> > +
> > +	err = rcar_gen4_add_pcie_ep(rcar);
> > +	if (err)
> > +		goto err_unprepare;
> > +
> > +	return 0;
> > +
> > +err_unprepare:
> > +	rcar_gen4_pcie_unprepare(rcar);
> > +
> > +	return err;
> > +}
> > +
> > +static void rcar_gen4_pcie_ep_remove(struct platform_device *pdev)
> > +{
> > +	struct rcar_gen4_pcie *rcar = platform_get_drvdata(pdev);
> > +
> > +	rcar_gen4_remove_pcie_ep(rcar);
> > +	rcar_gen4_pcie_unprepare(rcar);
> > +}
> > +
> > +static const struct of_device_id rcar_gen4_pcie_of_match[] = {
> > +	{ .compatible = "renesas,rcar-gen4-pcie-ep", },
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(of, rcar_gen4_pcie_of_match);
> > +
> > +static struct platform_driver rcar_gen4_pcie_ep_driver = {
> > +	.driver = {
> > +		.name = "pcie-rcar-gen4-ep",
> > +		.of_match_table = rcar_gen4_pcie_of_match,
> > +	},
> > +	.probe = rcar_gen4_pcie_ep_probe,
> > +	.remove_new = rcar_gen4_pcie_ep_remove,
> > +};
> > +module_platform_driver(rcar_gen4_pcie_ep_driver);
> > +
> > +MODULE_DESCRIPTION("Renesas R-Car Gen4 PCIe endpoint controller driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.25.1
> >