+/*
+ * Check whether a given set of supplies is available in a device tree node.
+ * This is used to check whether the new or the legacy device tree bindings
+ * should be used.
+ */
+static bool of_regulator_bulk_available(struct device_node *np,
+ struct regulator_bulk_data *supplies,
+ unsigned int num_supplies)
+{
+ char property[32];
+ unsigned int i;
+
+ for (i = 0; i < num_supplies; i++) {
+ snprintf(property, 32, "%s-supply", supplies[i].supply);
+
+ if (of_find_property(np, property, NULL) == NULL)
+ return false;
+ }
+
+ return true;
+}
+
+/*
+ * Old versions of the device tree binding for this device used a set of power
+ * supplies that didn't match the hardware inputs. This happened to work for a
+ * number of cases but is not future proof. However to preserve backwards-
+ * compatibility with old device trees, this function will try to use the old
+ * set of supplies.
+ */
+static int tegra_pcie_get_legacy_regulators(struct tegra_pcie *pcie)
+{
+ struct device_node *np = pcie->dev->of_node;
+
+ if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
+ pcie->num_supplies = 3;
+ else if (of_device_is_compatible(np, "nvidia,tegra20-pcie"))
+ pcie->num_supplies = 2;
+
+ if (pcie->num_supplies == 0) {
+ dev_err(pcie->dev, "device %s not supported in legacy mode\n",
+ np->full_name);
+ return -ENODEV;
+ }
+
+ pcie->supplies = devm_kcalloc(pcie->dev, pcie->num_supplies,
+ sizeof(*pcie->supplies),
+ GFP_KERNEL);
+ if (!pcie->supplies)
+ return -ENOMEM;
+
+ pcie->supplies[0].supply = "pex-clk";
+ pcie->supplies[1].supply = "vdd";
+
+ if (pcie->num_supplies > 2)
+ pcie->supplies[2].supply = "avdd";
+
+ return devm_regulator_bulk_get(pcie->dev, pcie->num_supplies,
+ pcie->supplies);
+}
+
+/*
+ * Obtains the list of regulators required for a particular generation of the
+ * IP block.
+ *
+ * This would've been nice to do simply by providing static tables for use
+ * with the regulator_bulk_*() API, but unfortunately Tegra30 is a bit quirky
+ * in that it has two pairs or AVDD_PEX and VDD_PEX supplies (PEXA and PEXB)
+ * and either seems to be optional depending on which ports are being used.
+ */
+static int tegra_pcie_get_regulators(struct tegra_pcie *pcie, u32 lane_mask)
+{
+ struct device_node *np = pcie->dev->of_node;
+ unsigned int i = 0;
+
+ if (of_device_is_compatible(np, "nvidia,tegra30-pcie")) {
+ bool need_pexa = false, need_pexb = false;
+
+ /* VDD_PEXA and AVDD_PEXA supply lanes 0 to 3 */
+ if (lane_mask & 0x0f)
+ need_pexa = true;
+
+ /* VDD_PEXB and AVDD_PEXB supply lanes 4 to 5 */
+ if (lane_mask & 0x30)
+ need_pexb = true;
+
+ pcie->num_supplies = 4 + (need_pexa ? 2 : 0) +
+ (need_pexb ? 2 : 0);
+
+ pcie->supplies = devm_kcalloc(pcie->dev, pcie->num_supplies,
+ sizeof(*pcie->supplies),
+ GFP_KERNEL);
+ if (!pcie->supplies)
+ return -ENOMEM;
+
+ pcie->supplies[i++].supply = "avdd-pex-pll";
+ pcie->supplies[i++].supply = "hvdd-pex";
+ pcie->supplies[i++].supply = "vddio-pex-ctl";
+ pcie->supplies[i++].supply = "avdd-plle";
+
+ if (need_pexa) {
+ pcie->supplies[i++].supply = "avdd-pexa";
+ pcie->supplies[i++].supply = "vdd-pexa";
+ }
+
+ if (need_pexb) {
+ pcie->supplies[i++].supply = "avdd-pexb";
+ pcie->supplies[i++].supply = "vdd-pexb";
+ }
+ } else if (of_device_is_compatible(np, "nvidia,tegra20-pcie")) {
+ pcie->num_supplies = 5;
+
+ pcie->supplies = devm_kcalloc(pcie->dev, pcie->num_supplies,
+ sizeof(*pcie->supplies),
+ GFP_KERNEL);
+ if (!pcie->supplies)
+ return -ENOMEM;
+
+ pcie->supplies[0].supply = "avdd-pex";
+ pcie->supplies[1].supply = "vdd-pex";
+ pcie->supplies[2].supply = "avdd-pex-pll";
+ pcie->supplies[3].supply = "avdd-plle";
+ pcie->supplies[4].supply = "vddio-pex-clk";
+ }
+
+ if (of_regulator_bulk_available(pcie->dev->of_node, pcie->supplies,
+ pcie->num_supplies))
+ return devm_regulator_bulk_get(pcie->dev, pcie->num_supplies,
+ pcie->supplies);
+
+ /*
+ * If not all regulators are available for this new scheme, assume
+ * that the device tree complies with an older version of the device
+ * tree binding.
+ */
+ dev_info(pcie->dev, "using legacy DT binding for power supplies\n");
+
+ devm_kfree(pcie->dev, pcie->supplies);
+ pcie->num_supplies = 0;
+
+ return tegra_pcie_get_legacy_regulators(pcie);
+}
+