[PATCH 6.1 011/215] PCI: layerscape: Add the endpoint linkup notifier support

Greg Kroah-Hartman
2024-03-04T21:42:42Z

From: Frank Li <Frank.Li@nxp.com>

[ Upstream commit 061cbfab09fb35898f2907d42f936cf9ae271d93 ]

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.

Link: https://lore.kernel.org/r/20230515151049.2797105-1-Frank.Li@nxp.com
Signed-off-by: Xiaowei Bao <xiaowei.bao@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../pci/controller/dwc/pci-layerscape-ep.c | 100 +++++++++++++++++-
1 file changed, 99 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c
index ad99707b3b994..5b27554e071a1 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 +44,84 @@ 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)
+ 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)
{
@@ -124,6 +214,7 @@ 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)
@@ -143,6 +234,7 @@ 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;
@@ -154,9 +246,15 @@ 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 = {
--
2.43.0