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authorBjorn Helgaas <bhelgaas@google.com>2025-06-04 10:50:42 -0500
committerBjorn Helgaas <bhelgaas@google.com>2025-06-04 10:50:42 -0500
commit05cf00aa05afed0d6808cce6654ef8be457fb6bb (patch)
treeef9470ba6b660beb077f8dc8f041523814b752b7 /drivers/pci/of.c
parentc7b9c591245e32b5c7b235f48485497e1e8f9e2a (diff)
parent3e5127469a8d41153fb30031a271788f52dd17ec (diff)
Merge branch 'pci/controller/qcom'
- Add OF support for parsing DT 'eq-presets-<N>gts' property for lane equalization presets (Krishna Chaitanya Chundru) - Read Maximum Link Width from the Link Capabilities register if DT lacks 'num-lanes' property (Krishna Chaitanya Chundru) - Add Physical Layer 64 GT/s Capability ID and register offsets for 8, 32, and 64 GT/s lane equalization registers (Krishna Chaitanya Chundru) - Add generic dwc support for configuring lane equalization presets (Krishna Chaitanya Chundru) - Add DT and driver support for PCIe on IPQ5018 SoC (Nitheesh Sekar) * pci/controller/qcom: PCI: qcom: Add support for IPQ5018 dt-bindings: PCI: qcom: Add IPQ5018 SoC PCI: dwc: Add support for configuring lane equalization presets PCI: Add lane equalization register offsets PCI: dwc: Update pci->num_lanes to maximum supported link width PCI: of: Add of_pci_get_equalization_presets() API
Diffstat (limited to 'drivers/pci/of.c')
-rw-r--r--drivers/pci/of.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index ab7a8252bf41..3579265f1198 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -966,3 +966,47 @@ u32 of_pci_get_slot_power_limit(struct device_node *node,
return slot_power_limit_mw;
}
EXPORT_SYMBOL_GPL(of_pci_get_slot_power_limit);
+
+/**
+ * of_pci_get_equalization_presets - Parses the "eq-presets-Ngts" property.
+ *
+ * @dev: Device containing the properties.
+ * @presets: Pointer to store the parsed data.
+ * @num_lanes: Maximum number of lanes supported.
+ *
+ * If the property is present, read and store the data in the @presets structure.
+ * Else, assign a default value of PCI_EQ_RESV.
+ *
+ * Return: 0 if the property is not available or successfully parsed else
+ * errno otherwise.
+ */
+int of_pci_get_equalization_presets(struct device *dev,
+ struct pci_eq_presets *presets,
+ int num_lanes)
+{
+ char name[20];
+ int ret;
+
+ presets->eq_presets_8gts[0] = PCI_EQ_RESV;
+ ret = of_property_read_u16_array(dev->of_node, "eq-presets-8gts",
+ presets->eq_presets_8gts, num_lanes);
+ if (ret && ret != -EINVAL) {
+ dev_err(dev, "Error reading eq-presets-8gts: %d\n", ret);
+ return ret;
+ }
+
+ for (int i = 0; i < EQ_PRESET_TYPE_MAX - 1; i++) {
+ presets->eq_presets_Ngts[i][0] = PCI_EQ_RESV;
+ snprintf(name, sizeof(name), "eq-presets-%dgts", 8 << (i + 1));
+ ret = of_property_read_u8_array(dev->of_node, name,
+ presets->eq_presets_Ngts[i],
+ num_lanes);
+ if (ret && ret != -EINVAL) {
+ dev_err(dev, "Error reading %s: %d\n", name, ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(of_pci_get_equalization_presets);