Re: [PATCH v4 1/1] PCI: layerscape: Add the endpoint linkup notifier support

Lorenzo Pieralisi
2023-06-15T08:15:34Z

On Mon, May 15, 2023 at 11:10:49AM -0400, Frank Li wrote:
> Layerscape has PME interrupt, which can be used as linkup notifier.
> Set CFG_READY bit of PEX_PF0_CONFIG to enable accesses from root complex
> when linkup detected.
>
> Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Signed-off-by: Xiaowei Bao <xiaowei.bao@nxp.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
> Change from v3 to v4
> - swap irq and big_endian
> Change from v2 to v3
> - align 80 column
> - clear irq firstly
> - dev_info to dev_dbg
> - remove double space
> - update commit message
>
> Change from v1 to v2
> - pme -> PME
> - irq -> IRQ
> - update dev_info message according to Bjorn's suggestion
>
> .../pci/controller/dwc/pci-layerscape-ep.c | 102 +++++++++++++++++-
> 1 file changed, 101 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c
> index c640db60edc6..5398641b6b7e 100644
> --- a/drivers/pci/controller/dwc/pci-layerscape-ep.c
> +++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c
> @@ -18,6 +18,20 @@
>
> #include "pcie-designware.h"
>
> +#define PEX_PF0_CONFIG 0xC0014
> +#define PEX_PF0_CFG_READY BIT(0)
> +
> +/* PEX PFa PCIE PME and message interrupt registers*/
> +#define PEX_PF0_PME_MES_DR 0xC0020
> +#define PEX_PF0_PME_MES_DR_LUD BIT(7)
> +#define PEX_PF0_PME_MES_DR_LDD BIT(9)
> +#define PEX_PF0_PME_MES_DR_HRD BIT(10)
> +
> +#define PEX_PF0_PME_MES_IER 0xC0028
> +#define PEX_PF0_PME_MES_IER_LUDIE BIT(7)
> +#define PEX_PF0_PME_MES_IER_LDDIE BIT(9)
> +#define PEX_PF0_PME_MES_IER_HRDIE BIT(10)
> +
> #define to_ls_pcie_ep(x) dev_get_drvdata((x)->dev)
>
> struct ls_pcie_ep_drvdata {
> @@ -30,8 +44,86 @@ struct ls_pcie_ep {
> struct dw_pcie *pci;
> struct pci_epc_features *ls_epc;
> const struct ls_pcie_ep_drvdata *drvdata;
> + int irq;
> + bool big_endian;
> };
>
> +static u32 ls_lut_readl(struct ls_pcie_ep *pcie, u32 offset)
> +{
> + struct dw_pcie *pci = pcie->pci;
> +
> + if (pcie->big_endian)
> + return ioread32be(pci->dbi_base + offset);
> + else
> + return ioread32(pci->dbi_base + offset);
> +}
> +
> +static void ls_lut_writel(struct ls_pcie_ep *pcie, u32 offset, u32 value)
> +{
> + struct dw_pcie *pci = pcie->pci;
> +
> + if (pcie->big_endian)
> + iowrite32be(value, pci->dbi_base + offset);
> + else
> + iowrite32(value, pci->dbi_base + offset);
> +}
> +
> +static irqreturn_t ls_pcie_ep_event_handler(int irq, void *dev_id)
> +{
> + struct ls_pcie_ep *pcie = dev_id;
> + struct dw_pcie *pci = pcie->pci;
> + u32 val, cfg;
> +
> + val = ls_lut_readl(pcie, PEX_PF0_PME_MES_DR);
> + ls_lut_writel(pcie, PEX_PF0_PME_MES_DR, val);
> +
> + if (!val)
> + return IRQ_NONE;
> +
> + if (val & PEX_PF0_PME_MES_DR_LUD) {
> + cfg = ls_lut_readl(pcie, PEX_PF0_CONFIG);
> + cfg |= PEX_PF0_CFG_READY;
> + ls_lut_writel(pcie, PEX_PF0_CONFIG, cfg);
> + dw_pcie_ep_linkup(&pci->ep);
> +
> + dev_dbg(pci->dev, "Link up\n");
> + } else if (val & PEX_PF0_PME_MES_DR_LDD) {
> + dev_dbg(pci->dev, "Link down\n");
> + } else if (val & PEX_PF0_PME_MES_DR_HRD) {
> + dev_dbg(pci->dev, "Hot reset\n");
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int ls_pcie_ep_interrupt_init(struct ls_pcie_ep *pcie,
> + struct platform_device *pdev)
> +{
> + u32 val;
> + int ret;
> +
> + pcie->irq = platform_get_irq_byname(pdev, "pme");
> + if (pcie->irq < 0) {
> + dev_err(&pdev->dev, "Can't get 'pme' IRQ\n");

I will remove this log, platform_get_irq_byname() already logs an
error.

Lorenzo

> + return pcie->irq;
> + }
> +
> + ret = devm_request_irq(&pdev->dev, pcie->irq, ls_pcie_ep_event_handler,
> + IRQF_SHARED, pdev->name, pcie);
> + if (ret) {
> + dev_err(&pdev->dev, "Can't register PCIe IRQ\n");
> + return ret;
> + }
> +
> + /* Enable interrupts */
> + val = ls_lut_readl(pcie, PEX_PF0_PME_MES_IER);
> + val |= PEX_PF0_PME_MES_IER_LDDIE | PEX_PF0_PME_MES_IER_HRDIE |
> + PEX_PF0_PME_MES_IER_LUDIE;
> + ls_lut_writel(pcie, PEX_PF0_PME_MES_IER, val);
> +
> + return 0;
> +}
> +
> static const struct pci_epc_features*
> ls_pcie_ep_get_features(struct dw_pcie_ep *ep)
> {
> @@ -125,6 +217,7 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev)
> struct ls_pcie_ep *pcie;
> struct pci_epc_features *ls_epc;
> struct resource *dbi_base;
> + int ret;
>
> pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
> if (!pcie)
> @@ -144,6 +237,7 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev)
> pci->ops = pcie->drvdata->dw_pcie_ops;
>
> ls_epc->bar_fixed_64bit = (1 << BAR_2) | (1 << BAR_4);
> + ls_epc->linkup_notifier = true;
>
> pcie->pci = pci;
> pcie->ls_epc = ls_epc;
> @@ -155,9 +249,15 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev)
>
> pci->ep.ops = &ls_pcie_ep_ops;
>
> + pcie->big_endian = of_property_read_bool(dev->of_node, "big-endian");
> +
> platform_set_drvdata(pdev, pcie);
>
> - return dw_pcie_ep_init(&pci->ep);
> + ret = dw_pcie_ep_init(&pci->ep);
> + if (ret)
> + return ret;
> +
> + return ls_pcie_ep_interrupt_init(pcie, pdev);
> }
>
> static struct platform_driver ls_pcie_ep_driver = {
> --
> 2.34.1