diff options
Diffstat (limited to 'drivers/pci/controller/dwc/pcie-amd-mdb.c')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-amd-mdb.c | 52 |
1 files changed, 51 insertions, 1 deletions
diff --git a/drivers/pci/controller/dwc/pcie-amd-mdb.c b/drivers/pci/controller/dwc/pcie-amd-mdb.c index 9f7251a16d32..3c6e837465bb 100644 --- a/drivers/pci/controller/dwc/pcie-amd-mdb.c +++ b/drivers/pci/controller/dwc/pcie-amd-mdb.c @@ -18,6 +18,7 @@ #include <linux/resource.h> #include <linux/types.h> +#include "../../pci.h" #include "pcie-designware.h" #define AMD_MDB_TLP_IR_STATUS_MISC 0x4C0 @@ -56,6 +57,7 @@ * @slcr: MDB System Level Control and Status Register (SLCR) base * @intx_domain: INTx IRQ domain pointer * @mdb_domain: MDB IRQ domain pointer + * @perst_gpio: GPIO descriptor for PERST# signal handling * @intx_irq: INTx IRQ interrupt number */ struct amd_mdb_pcie { @@ -63,6 +65,7 @@ struct amd_mdb_pcie { void __iomem *slcr; struct irq_domain *intx_domain; struct irq_domain *mdb_domain; + struct gpio_desc *perst_gpio; int intx_irq; }; @@ -284,7 +287,7 @@ static int amd_mdb_pcie_init_irq_domains(struct amd_mdb_pcie *pcie, struct device_node *pcie_intc_node; int err; - pcie_intc_node = of_get_next_child(node, NULL); + pcie_intc_node = of_get_child_by_name(node, "interrupt-controller"); if (!pcie_intc_node) { dev_err(dev, "No PCIe Intc node found\n"); return -ENODEV; @@ -402,6 +405,28 @@ static int amd_mdb_setup_irq(struct amd_mdb_pcie *pcie, return 0; } +static int amd_mdb_parse_pcie_port(struct amd_mdb_pcie *pcie) +{ + struct device *dev = pcie->pci.dev; + struct device_node *pcie_port_node __maybe_unused; + + /* + * This platform currently supports only one Root Port, so the loop + * will execute only once. + * TODO: Enhance the driver to handle multiple Root Ports in the future. + */ + for_each_child_of_node_with_prefix(dev->of_node, pcie_port_node, "pcie") { + pcie->perst_gpio = devm_fwnode_gpiod_get(dev, of_fwnode_handle(pcie_port_node), + "reset", GPIOD_OUT_HIGH, NULL); + if (IS_ERR(pcie->perst_gpio)) + return dev_err_probe(dev, PTR_ERR(pcie->perst_gpio), + "Failed to request reset GPIO\n"); + return 0; + } + + return -ENODEV; +} + static int amd_mdb_add_pcie_port(struct amd_mdb_pcie *pcie, struct platform_device *pdev) { @@ -426,6 +451,12 @@ static int amd_mdb_add_pcie_port(struct amd_mdb_pcie *pcie, pp->ops = &amd_mdb_pcie_host_ops; + if (pcie->perst_gpio) { + mdelay(PCIE_T_PVPERL_MS); + gpiod_set_value_cansleep(pcie->perst_gpio, 0); + mdelay(PCIE_RESET_CONFIG_WAIT_MS); + } + err = dw_pcie_host_init(pp); if (err) { dev_err(dev, "Failed to initialize host, err=%d\n", err); @@ -444,6 +475,7 @@ static int amd_mdb_pcie_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct amd_mdb_pcie *pcie; struct dw_pcie *pci; + int ret; pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL); if (!pcie) @@ -454,6 +486,24 @@ static int amd_mdb_pcie_probe(struct platform_device *pdev) platform_set_drvdata(pdev, pcie); + ret = amd_mdb_parse_pcie_port(pcie); + /* + * If amd_mdb_parse_pcie_port returns -ENODEV, it indicates that the + * PCIe Bridge node was not found in the device tree. This is not + * considered a fatal error and will trigger a fallback where the + * reset GPIO is acquired directly from the PCIe Host Bridge node. + */ + if (ret) { + if (ret != -ENODEV) + return ret; + + pcie->perst_gpio = devm_gpiod_get_optional(dev, "reset", + GPIOD_OUT_HIGH); + if (IS_ERR(pcie->perst_gpio)) + return dev_err_probe(dev, PTR_ERR(pcie->perst_gpio), + "Failed to request reset GPIO\n"); + } + return amd_mdb_add_pcie_port(pcie, pdev); } |