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

6 files changed, 167 insertions, 1 deletions

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index d1cd48efad43..d40c06c515ce 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -523,6 +523,13 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
 
 	dw_pcie_iatu_detect(pci);
 
+	if (pci->num_lanes < 1)
+		pci->num_lanes = dw_pcie_link_get_max_link_width(pci);
+
+	ret = of_pci_get_equalization_presets(dev, &pp->presets, pci->num_lanes);
+	if (ret)
+		goto err_free_msi;
+
 	/*
 	 * Allocate the resource for MSG TLP before programming the iATU
 	 * outbound window in dw_pcie_setup_rc(). Since the allocation depends
@@ -828,6 +835,77 @@ static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp)
 	return 0;
 }
 
+static void dw_pcie_program_presets(struct dw_pcie_rp *pp, enum pci_bus_speed speed)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	u8 lane_eq_offset, lane_reg_size, cap_id;
+	u8 *presets;
+	u32 cap;
+	int i;
+
+	if (speed == PCIE_SPEED_8_0GT) {
+		presets = (u8 *)pp->presets.eq_presets_8gts;
+		lane_eq_offset =  PCI_SECPCI_LE_CTRL;
+		cap_id = PCI_EXT_CAP_ID_SECPCI;
+		/* For data rate of 8 GT/S each lane equalization control is 16bits wide*/
+		lane_reg_size = 0x2;
+	} else if (speed == PCIE_SPEED_16_0GT) {
+		presets = pp->presets.eq_presets_Ngts[EQ_PRESET_TYPE_16GTS - 1];
+		lane_eq_offset = PCI_PL_16GT_LE_CTRL;
+		cap_id = PCI_EXT_CAP_ID_PL_16GT;
+		lane_reg_size = 0x1;
+	} else if (speed == PCIE_SPEED_32_0GT) {
+		presets =  pp->presets.eq_presets_Ngts[EQ_PRESET_TYPE_32GTS - 1];
+		lane_eq_offset = PCI_PL_32GT_LE_CTRL;
+		cap_id = PCI_EXT_CAP_ID_PL_32GT;
+		lane_reg_size = 0x1;
+	} else if (speed == PCIE_SPEED_64_0GT) {
+		presets =  pp->presets.eq_presets_Ngts[EQ_PRESET_TYPE_64GTS - 1];
+		lane_eq_offset = PCI_PL_64GT_LE_CTRL;
+		cap_id = PCI_EXT_CAP_ID_PL_64GT;
+		lane_reg_size = 0x1;
+	} else {
+		return;
+	}
+
+	if (presets[0] == PCI_EQ_RESV)
+		return;
+
+	cap = dw_pcie_find_ext_capability(pci, cap_id);
+	if (!cap)
+		return;
+
+	/*
+	 * Write preset values to the registers byte-by-byte for the given
+	 * number of lanes and register size.
+	 */
+	for (i = 0; i < pci->num_lanes * lane_reg_size; i++)
+		dw_pcie_writeb_dbi(pci, cap + lane_eq_offset + i, presets[i]);
+}
+
+static void dw_pcie_config_presets(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	enum pci_bus_speed speed = pcie_link_speed[pci->max_link_speed];
+
+	/*
+	 * Lane equalization settings need to be applied for all data rates the
+	 * controller supports and for all supported lanes.
+	 */
+
+	if (speed >= PCIE_SPEED_8_0GT)
+		dw_pcie_program_presets(pp, PCIE_SPEED_8_0GT);
+
+	if (speed >= PCIE_SPEED_16_0GT)
+		dw_pcie_program_presets(pp, PCIE_SPEED_16_0GT);
+
+	if (speed >= PCIE_SPEED_32_0GT)
+		dw_pcie_program_presets(pp, PCIE_SPEED_32_0GT);
+
+	if (speed >= PCIE_SPEED_64_0GT)
+		dw_pcie_program_presets(pp, PCIE_SPEED_64_0GT);
+}
+
 int dw_pcie_setup_rc(struct dw_pcie_rp *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -881,6 +959,7 @@ int dw_pcie_setup_rc(struct dw_pcie_rp *pp)
 		PCI_COMMAND_MASTER | PCI_COMMAND_SERR;
 	dw_pcie_writel_dbi(pci, PCI_COMMAND, val);
 
+	dw_pcie_config_presets(pp);
 	/*
 	 * If the platform provides its own child bus config accesses, it means
 	 * the platform uses its own address translation component rather than
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 5e353f67462b..b1c65f403809 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -781,6 +781,14 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci)
 
 }
 
+int dw_pcie_link_get_max_link_width(struct dw_pcie *pci)
+{
+	u8 cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u32 lnkcap = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP);
+
+	return FIELD_GET(PCI_EXP_LNKCAP_MLW, lnkcap);
+}
+
 static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes)
 {
 	u32 lnkcap, lwsc, plc;
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 4dd16aa4b39e..d1e7b416db93 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -25,6 +25,8 @@
 #include <linux/pci-epc.h>
 #include <linux/pci-epf.h>
 
+#include "../../pci.h"
+
 /* DWC PCIe IP-core versions (native support since v4.70a) */
 #define DW_PCIE_VER_365A		0x3336352a
 #define DW_PCIE_VER_460A		0x3436302a
@@ -412,6 +414,7 @@ struct dw_pcie_rp {
 	int			msg_atu_index;
 	struct resource		*msg_res;
 	bool			use_linkup_irq;
+	struct pci_eq_presets	presets;
 };
 
 struct dw_pcie_ep_ops {
@@ -540,6 +543,7 @@ void dw_pcie_write_dbi2(struct dw_pcie *pci, u32 reg, size_t size, u32 val);
 bool dw_pcie_link_up(struct dw_pcie *pci);
 void dw_pcie_upconfig_setup(struct dw_pcie *pci);
 int dw_pcie_wait_for_link(struct dw_pcie *pci);
+int dw_pcie_link_get_max_link_width(struct dw_pcie *pci);
 int dw_pcie_prog_outbound_atu(struct dw_pcie *pci,
 			      const struct dw_pcie_ob_atu_cfg *atu);
 int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int type,
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index a623ed0fbc2f..c789e3f85655 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1840,6 +1840,7 @@ static const struct of_device_id qcom_pcie_match[] = {
 	{ .compatible = "qcom,pcie-apq8064", .data = &cfg_2_1_0 },
 	{ .compatible = "qcom,pcie-apq8084", .data = &cfg_1_0_0 },
 	{ .compatible = "qcom,pcie-ipq4019", .data = &cfg_2_4_0 },
+	{ .compatible = "qcom,pcie-ipq5018", .data = &cfg_2_9_0 },
 	{ .compatible = "qcom,pcie-ipq6018", .data = &cfg_2_9_0 },
 	{ .compatible = "qcom,pcie-ipq8064", .data = &cfg_2_1_0 },
 	{ .compatible = "qcom,pcie-ipq8064-v2", .data = &cfg_2_1_0 },
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);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 5cf429e0016e..e39a2a5df587 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -9,6 +9,8 @@ struct pcie_tlp_log;
 /* Number of possible devfns: 0.0 to 1f.7 inclusive */
 #define MAX_NR_DEVFNS 256
 
+#define MAX_NR_LANES 16
+
 #define PCI_FIND_CAP_TTL	48
 
 #define PCI_VSEC_ID_INTEL_TBT	0x1234	/* Thunderbolt */
@@ -891,6 +893,21 @@ static inline u64 pci_rebar_size_to_bytes(int size)
 
 struct device_node;
 
+#define PCI_EQ_RESV	0xff
+
+enum equalization_preset_type {
+	EQ_PRESET_TYPE_8GTS,
+	EQ_PRESET_TYPE_16GTS,
+	EQ_PRESET_TYPE_32GTS,
+	EQ_PRESET_TYPE_64GTS,
+	EQ_PRESET_TYPE_MAX
+};
+
+struct pci_eq_presets {
+	u16 eq_presets_8gts[MAX_NR_LANES];
+	u8 eq_presets_Ngts[EQ_PRESET_TYPE_MAX - 1][MAX_NR_LANES];
+};
+
 #ifdef CONFIG_OF
 int of_get_pci_domain_nr(struct device_node *node);
 int of_pci_get_max_link_speed(struct device_node *node);
@@ -905,7 +922,9 @@ void pci_release_bus_of_node(struct pci_bus *bus);
 
 int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge *bridge);
 bool of_pci_supply_present(struct device_node *np);
-
+int of_pci_get_equalization_presets(struct device *dev,
+				    struct pci_eq_presets *presets,
+				    int num_lanes);
 #else
 static inline int
 of_get_pci_domain_nr(struct device_node *node)
@@ -950,6 +969,17 @@ static inline bool of_pci_supply_present(struct device_node *np)
 {
 	return false;
 }
+
+static inline int of_pci_get_equalization_presets(struct device *dev,
+						  struct pci_eq_presets *presets,
+						  int num_lanes)
+{
+	presets->eq_presets_8gts[0] = PCI_EQ_RESV;
+	for (int i = 0; i < EQ_PRESET_TYPE_MAX - 1; i++)
+		presets->eq_presets_Ngts[i][0] = PCI_EQ_RESV;
+
+	return 0;
+}
 #endif /* CONFIG_OF */
 
 struct of_changeset;