Merge branch 'remotes/lorenzo/pci/qcom'

- Add DT and driver support for SC8280XP/SA8540P basic interconnects where
  interconnect bandwidth must be requested before enabling interconnect
  clocks (Johan Hovold)

- Add 'dma-coherent' property (Johan Hovold)

* remotes/lorenzo/pci/qcom:
  dt-bindings: PCI: qcom: Allow 'dma-coherent' property
  PCI: qcom: Add basic interconnect support
  dt-bindings: PCI: qcom: Add SC8280XP/SA8540P interconnects

1 files changed, 76 insertions, 0 deletions

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index cf27345f6575..38d5d46487bb 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -12,6 +12,7 @@
 #include <linux/crc8.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
+#include <linux/interconnect.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
@@ -223,6 +224,7 @@ struct qcom_pcie {
 	union qcom_pcie_resources res;
 	struct phy *phy;
 	struct gpio_desc *reset;
+	struct icc_path *icc_mem;
 	const struct qcom_pcie_cfg *cfg;
 };
 
@@ -1639,6 +1641,74 @@ static const struct dw_pcie_ops dw_pcie_ops = {
 	.start_link = qcom_pcie_start_link,
 };
 
+static int qcom_pcie_icc_init(struct qcom_pcie *pcie)
+{
+	struct dw_pcie *pci = pcie->pci;
+	int ret;
+
+	pcie->icc_mem = devm_of_icc_get(pci->dev, "pcie-mem");
+	if (IS_ERR(pcie->icc_mem))
+		return PTR_ERR(pcie->icc_mem);
+
+	/*
+	 * Some Qualcomm platforms require interconnect bandwidth constraints
+	 * to be set before enabling interconnect clocks.
+	 *
+	 * Set an initial peak bandwidth corresponding to single-lane Gen 1
+	 * for the pcie-mem path.
+	 */
+	ret = icc_set_bw(pcie->icc_mem, 0, MBps_to_icc(250));
+	if (ret) {
+		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void qcom_pcie_icc_update(struct qcom_pcie *pcie)
+{
+	struct dw_pcie *pci = pcie->pci;
+	u32 offset, status, bw;
+	int speed, width;
+	int ret;
+
+	if (!pcie->icc_mem)
+		return;
+
+	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
+
+	/* Only update constraints if link is up. */
+	if (!(status & PCI_EXP_LNKSTA_DLLLA))
+		return;
+
+	speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
+	width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
+
+	switch (speed) {
+	case 1:
+		bw = MBps_to_icc(250);
+		break;
+	case 2:
+		bw = MBps_to_icc(500);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		fallthrough;
+	case 3:
+		bw = MBps_to_icc(985);
+		break;
+	}
+
+	ret = icc_set_bw(pcie->icc_mem, 0, width * bw);
+	if (ret) {
+		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
+			ret);
+	}
+}
+
 static int qcom_pcie_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1699,6 +1769,10 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 		goto err_pm_runtime_put;
 	}
 
+	ret = qcom_pcie_icc_init(pcie);
+	if (ret)
+		goto err_pm_runtime_put;
+
 	ret = pcie->cfg->ops->get_resources(pcie);
 	if (ret)
 		goto err_pm_runtime_put;
@@ -1717,6 +1791,8 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 		goto err_phy_exit;
 	}
 
+	qcom_pcie_icc_update(pcie);
+
 	return 0;
 
 err_phy_exit: