Hi Geert-san,
> From: Geert Uytterhoeven, Sent: Tuesday, June 28, 2022 4:46 PM
>
> Hi Shimoda-san,
>
> On Mon, Jun 27, 2022 at 2:24 PM Yoshihiro Shimoda
> <yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
> > Add R-Car Gen4 PCIe Host support. This controller is based on
> > Synopsys DesignWare PCIe.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
>
> Thanks for your patch!
Thank you for your review!
> > --- /dev/null
> > +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4-host.c
> > @@ -0,0 +1,205 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * PCIe host controller driver for Renesas R-Car Gen4 Series SoCs
> > + * Copyright (C) 2022 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"
> > +
> > +static int rcar_gen4_pcie_host_init(struct pcie_port *pp)
> > +{
> > + struct dw_pcie *dw = to_dw_pcie_from_pp(pp);
> > + struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
> > + int ret;
> > + u32 val;
> > +
> > + rcar_gen4_pcie_set_device_type(rcar, true, dw->num_lanes);
> > +
> > + dw_pcie_dbi_ro_wr_en(dw);
> > +
> > + /* Enable L1 Substates */
> > + val = dw_pcie_readl_dbi(dw, L1PSCAP(PCI_L1SS_CTL1));
> > + val &= ~PCI_L1SS_CTL1_L1SS_MASK;
> > + val |= PCI_L1SS_CTL1_PCIPM_L1_2 | PCI_L1SS_CTL1_PCIPM_L1_1 |
> > + PCI_L1SS_CTL1_ASPM_L1_2 | PCI_L1SS_CTL1_ASPM_L1_1;
> > + dw_pcie_writel_dbi(dw, L1PSCAP(PCI_L1SS_CTL1), val);
> > +
> > + rcar_gen4_pcie_disable_bar(dw, BAR0MASKF);
> > + rcar_gen4_pcie_disable_bar(dw, BAR1MASKF);
> > +
> > + /* Set Root Control */
> > + val = dw_pcie_readl_dbi(dw, EXPCAP(PCI_EXP_RTCTL));
> > + val |= PCI_EXP_RTCTL_SECEE | PCI_EXP_RTCTL_SENFEE |
> > + PCI_EXP_RTCTL_SEFEE | PCI_EXP_RTCTL_PMEIE |
> > + PCI_EXP_RTCTL_CRSSVE;
> > + dw_pcie_writel_dbi(dw, EXPCAP(PCI_EXP_RTCTL), val);
> > +
> > + /* Set Interrupt Disable, SERR# Enable, Parity Error Response */
> > + val = dw_pcie_readl_dbi(dw, PCI_COMMAND);
> > + val |= PCI_COMMAND_PARITY | PCI_COMMAND_SERR |
> > + PCI_COMMAND_INTX_DISABLE;
> > + dw_pcie_writel_dbi(dw, PCI_COMMAND, val);
> > +
> > + /* Enable SERR */
> > + val = dw_pcie_readb_dbi(dw, PCI_BRIDGE_CONTROL);
> > + val |= PCI_BRIDGE_CTL_SERR;
> > + dw_pcie_writeb_dbi(dw, PCI_BRIDGE_CONTROL, val);
> > +
> > + /* Device control */
> > + val = dw_pcie_readl_dbi(dw, EXPCAP(PCI_EXP_DEVCTL));
> > + val |= PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
> > + PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE;
> > + dw_pcie_writel_dbi(dw, EXPCAP(PCI_EXP_DEVCTL), val);
> > +
> > + dw_pcie_dbi_ro_wr_dis(dw);
> > +
> > + if (IS_ENABLED(CONFIG_PCI_MSI)) {
> > + /* Enable MSI interrupt signal */
> > + val = rcar_gen4_pcie_readl(rcar, PCIEINTSTS0EN);
> > + val |= MSI_CTRL_INT;
> > + rcar_gen4_pcie_writel(rcar, PCIEINTSTS0EN, val);
> > + }
> > +
> > + dw_pcie_setup_rc(pp);
> > +
> > + dw_pcie_dbi_ro_wr_en(dw);
> > + rcar_gen4_pcie_set_max_link_width(dw, dw->num_lanes);
> > + dw_pcie_dbi_ro_wr_dis(dw);
> > +
> > + if (!dw_pcie_link_up(dw)) {
> > + ret = dw->ops->start_link(dw);
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + /* Ignore errors, the link may come up later */
> > + if (dw_pcie_wait_for_link(dw))
> > + dev_info(dw->dev, "PCIe link down\n");
> > +
> > + return 0;
> > +}
> > +
> > +static const struct dw_pcie_host_ops rcar_gen4_pcie_host_ops = {
> > + .host_init = rcar_gen4_pcie_host_init,
> > +};
> > +
> > +static int rcar_gen4_add_pcie_port(struct rcar_gen4_pcie *rcar,
> > + struct platform_device *pdev)
> > +{
> > + struct dw_pcie *dw = &rcar->dw;
> > + struct pcie_port *pp = &dw->pp;
> > + int ret;
> > +
> > + if (IS_ENABLED(CONFIG_PCI_MSI)) {
> > + pp->msi_irq = platform_get_irq_byname(pdev, "others");
> > + if (pp->msi_irq < 0)
> > + return pp->msi_irq;
> > + }
> > +
> > + pp->ops = &rcar_gen4_pcie_host_ops;
> > +
> > + ret = dw_pcie_host_init(pp);
> > + if (ret) {
> > + dev_err(&pdev->dev, "Failed to initialize host\n");
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static void rcar_gen4_remove_pcie_port(struct rcar_gen4_pcie *rcar)
> > +{
> > + dw_pcie_host_deinit(&rcar->dw.pp);
> > +}
> > +
> > +static int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar,
> > + struct platform_device *pdev)
> > +{
> > + struct dw_pcie *dw = &rcar->dw;
> > +
> > + /* Renesas-specific registers */
> > + rcar->base = devm_platform_ioremap_resource_byname(pdev, "app");
> > + if (IS_ERR(rcar->base))
> > + return PTR_ERR(rcar->base);
> > +
> > + return rcar_gen4_pcie_devm_reset_get(rcar, dw->dev);
> > +}
> > +
> > +static int rcar_gen4_pcie_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_pm_runtime_enable(dev);
> > + if (err < 0) {
> > + dev_err(dev, "pm_runtime_get_sync failed\n");
> > + return err;
> > + }
> > +
> > + err = rcar_gen4_pcie_get_resources(rcar, pdev);
> > + if (err < 0) {
> > + dev_err(dev, "failed to request resource: %d\n", err);
> > + goto err_pm_put;
> > + }
> > +
> > + platform_set_drvdata(pdev, rcar);
> > +
> > + err = rcar_gen4_pcie_prepare(rcar);
> > + if (err < 0)
> > + goto err_pm_put;
> > +
> > + err = rcar_gen4_add_pcie_port(rcar, pdev);
> > + if (err < 0)
> > + goto err_host_disable;
> > +
> > + return 0;
> > +
> > +err_host_disable:
> > + rcar_gen4_pcie_unprepare(rcar);
> > +
> > +err_pm_put:
> > + rcar_gen4_pcie_pm_runtime_disable(dev);
> > +
> > + return err;
> > +}
> > +
> > +static int rcar_gen4_pcie_remove(struct platform_device *pdev)
> > +{
> > + struct rcar_gen4_pcie *rcar = platform_get_drvdata(pdev);
> > +
> > + rcar_gen4_remove_pcie_port(rcar);
> > + rcar_gen4_pcie_unprepare(rcar);
> > + rcar_gen4_pcie_pm_runtime_disable(&pdev->dev);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id rcar_gen4_pcie_of_match[] = {
> > + { .compatible = "renesas,rcar-gen4-pcie", },
> > + {},
> > +};
> > +
> > +static struct platform_driver rcar_gen4_pcie_driver = {
> > + .driver = {
> > + .name = "pcie-rcar-gen4",
> > + .of_match_table = rcar_gen4_pcie_of_match,
> > + },
> > + .probe = rcar_gen4_pcie_probe,
> > + .remove = rcar_gen4_pcie_remove,
> > +};
> > +module_platform_driver(rcar_gen4_pcie_driver);
> > +
> > +MODULE_DESCRIPTION("Renesas R-Car Gen4 PCIe host controller driver");
> > +MODULE_LICENSE("GPL");
> > diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> > new file mode 100644
> > index 000000000000..fa9588ed75e0
> > --- /dev/null
> > +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> > @@ -0,0 +1,172 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * PCIe host/endpoint controller driver for Renesas R-Car Gen4 Series SoCs
> > + * Copyright (C) 2022 Renesas Electronics Corporation
> > + */
> > +
> > +#include <linux/io.h>
> > +#include <linux/of_device.h>
> > +#include <linux/pci.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/reset.h>
> > +
> > +#include "pcie-rcar-gen4.h"
> > +#include "pcie-designware.h"
> > +
> > +/* Renesas-specific */
> > +#define PCIERSTCTRL1 0x0014
> > +#define APP_HOLD_PHY_RST BIT(16)
> > +#define APP_LTSSM_ENABLE BIT(0)
> > +
> > +#define DWC_VERSION 0x520a
> > +
> > +u32 rcar_gen4_pcie_readl(struct rcar_gen4_pcie *rcar, u32 reg)
> > +{
> > + return readl(rcar->base + reg);
> > +}
> > +
> > +void rcar_gen4_pcie_writel(struct rcar_gen4_pcie *rcar, u32 reg, u32 val)
> > +{
> > + writel(val, rcar->base + reg);
> > +}
>
> Do you really need helper functions for this? You need to type less
> when open-coding.
No, I don't need these functions. So, I'll remove them.
> If you insist, please make them static inline in the header file.
>
> > +int rcar_gen4_pcie_prepare(struct rcar_gen4_pcie *rcar)
> > +{
> > + return reset_control_deassert(rcar->rst);
> > +}
> > +
> > +void rcar_gen4_pcie_unprepare(struct rcar_gen4_pcie *rcar)
> > +{
> > + reset_control_assert(rcar->rst);
> > +}
>
> Static inline in header file?
I'm thinking that we can merge code of rcar_gen4_pcie_pm_runtime_enable()
and rcar_gen4_pcie_prepare(). If we cannot merge them, I'll change
the prepare/unprepare functions as static inline.
> > +
> > +int rcar_gen4_pcie_pm_runtime_enable(struct device *dev)
> > +{
> > + pm_runtime_enable(dev);
> > + return pm_runtime_get_sync(dev);
>
> Please use pm_runtime_resume_and_get() in new code.
I didn't know that. I'll fix it.
Best regards,
Yoshihiro Shimoda
