[v17,18/20] PCI: rcar-gen4-ep: Add R-Car Gen4 PCIe Endpoint support

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            |   9 +
 drivers/pci/controller/dwc/Makefile           |   2 +
 .../pci/controller/dwc/pcie-rcar-gen4-ep.c    | 191 ++++++++++++++++++
 3 files changed, 202 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pcie-rcar-gen4-ep.c

On Wed, Jul 05, 2023 at 08:42:04PM +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            |   9 +
>  drivers/pci/controller/dwc/Makefile           |   2 +
>  .../pci/controller/dwc/pcie-rcar-gen4-ep.c    | 191 ++++++++++++++++++
>  3 files changed, 202 insertions(+)
>  create mode 100644 drivers/pci/controller/dwc/pcie-rcar-gen4-ep.c
> 
> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> index 64d4d37bc891..4d877cd18374 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -424,4 +424,13 @@ config PCIE_RCAR_GEN4
>  	  Say Y here if you want PCIe host controller support on R-Car Gen4 SoCs.
>  	  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. This uses the DesignWare core.
> +
>  endmenu
> diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
> index 486cf706b53d..0fb0bde26ac4 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-drv-objs := pcie-rcar-gen4.o pcie-rcar-gen4-host.o
>  obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4-host-drv.o
> +pcie-rcar-gen4-ep-drv-objs := pcie-rcar-gen4.o pcie-rcar-gen4-ep.o
> +obj-$(CONFIG_PCIE_RCAR_GEN4_EP) += pcie-rcar-gen4-ep-drv.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.c b/drivers/pci/controller/dwc/pcie-rcar-gen4-ep.c
> new file mode 100644
> index 000000000000..1de33a9529bd
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4-ep.c
> @@ -0,0 +1,191 @@
> +// 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);

I don't see you disabling the clocks. It should be done in a
respective antagonistic method (like ep_deinit()?).
* The same concerns the Rcar Gen4 RP driver submitted in the previous
* patch.

> +	if (ret) {
> +		dev_err(dw->dev, "Failed to enable ref clocks\n");
> +		return;
> +	}
> +

> +	rcar_gen4_pcie_basic_init(rcar);

Please, see my note sent to the previous patch regarding having
rcar_gen4_pcie_basic_deinit().

> +
> +	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);
> +}
> +
> +static int rcar_gen4_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
> +				       enum pci_epc_irq_type type,
> +				       u16 interrupt_num)
> +{
> +	struct dw_pcie *dw = to_dw_pcie_from_ep(ep);
> +
> +	switch (type) {
> +	case PCI_EPC_IRQ_INTX:
> +		return dw_pcie_ep_raise_intx_irq(ep, func_no);
> +	case PCI_EPC_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_func_conf_select2(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 = {
> +	.ep_pre_init = rcar_gen4_pcie_ep_pre_init,
> +	.ep_init = rcar_gen4_pcie_ep_init,
> +	.ep_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,
> +	.func_conf_select2 = rcar_gen4_pcie_ep_func_conf_select2,
> +};
> +
> +static int rcar_gen4_add_pcie_ep(struct rcar_gen4_pcie *rcar,
> +				 struct platform_device *pdev)
> +{
> +	struct dw_pcie_ep *ep = &rcar->dw.ep;
> +	int ret;
> +
> +	rcar->mode = DW_PCIE_EP_TYPE;
> +	ep->ops = &pcie_ep_ops;
> +
> +	ret = dw_pcie_ep_init(ep);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to initialize endpoint\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +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 device *dev = &pdev->dev;
> +	struct rcar_gen4_pcie *rcar;
> +	int err;
> +
> +	rcar = rcar_gen4_pcie_devm_alloc(dev);
> +	if (!rcar)
> +		return -ENOMEM;
> +
> +	err = rcar_gen4_pcie_get_resources(rcar, pdev);
> +	if (err < 0) {
> +		dev_err(dev, "Failed to request resource: %d\n", err);
> +		return err;
> +	}
> +
> +	platform_set_drvdata(pdev, rcar);
> +
> +	err = rcar_gen4_pcie_prepare(rcar);
> +	if (err < 0)
> +		return err;
> +
> +	err = rcar_gen4_add_pcie_ep(rcar, pdev);
> +	if (err < 0)
> +		goto err_add;
> +
> +	return 0;
> +
> +err_add:
> +	rcar_gen4_pcie_unprepare(rcar);
> +
> +	return err;
> +}
> +

> +static int 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);
> +
> +	return 0;
> +}

Please convert this function to returning void and assign to the
platform_driver.remove_new pointer instead.

> +
> +static const struct of_device_id rcar_gen4_pcie_of_match[] = {
> +	{ .compatible = "renesas,rcar-gen4-pcie-ep", },
> +	{},
> +};
> +
> +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 = rcar_gen4_pcie_ep_remove,

ditto

-Serge(y)

> +};
> +module_platform_driver(rcar_gen4_pcie_ep_driver);
> +
> +MODULE_DESCRIPTION("Renesas R-Car Gen4 PCIe endpoint controller driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.25.1
>