Thread (9 messages) 9 messages, 4 authors, 2021-06-13
STALE1848d
Revisions (3)
  1. v1 [diff vs current]
  2. v2 current
  3. v3 [diff vs current]

[PATCH v2 3/5] pcie-qcom: provide a way to power up qca6390 chip on RB5 platform

From: Dmitry Baryshkov <hidden>
Date: 2021-01-28 17:53:56
Also in: linux-arm-msm, linux-pci, lkml
Subsystem: arm/qualcomm mailing list, pci native host bridge and endpoint drivers, pci subsystem, pcie driver for qualcomm msm, the rest · Maintainers: Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds

Some Qualcomm platforms require to power up an external device before
probing the PCI bus. E.g. on RB5 platform the QCA6390 WiFi/BT chip needs
to be powered up before PCIe0 bus is probed. Add a quirk to the
respective PCIe root bridge to attach to the power domain if one is
required, so that the QCA chip is started before scanning the PCIe bus.

Signed-off-by: Dmitry Baryshkov <redacted>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index ab21aa01c95d..eb73c8540d4d 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -20,6 +20,7 @@
 #include <linux/of_device.h>
 #include <linux/of_gpio.h>
 #include <linux/pci.h>
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 #include <linux/platform_device.h>
 #include <linux/phy/phy.h>
@@ -1568,6 +1569,26 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x0302, qcom_fixup_class);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1000, qcom_fixup_class);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1001, qcom_fixup_class);
 
+static void qcom_fixup_power(struct pci_dev *dev)
+{
+	int ret;
+	struct pcie_port *pp = dev->bus->sysdata;
+	struct dw_pcie *pci;
+
+	if (!pci_is_root_bus(dev->bus))
+		return;
+
+	ret = dev_pm_domain_attach(&dev->dev, true);
+	if (ret < 0 || !dev->dev.pm_domain)
+		return;
+
+	pci = to_dw_pcie_from_pp(pp);
+	dev_info(&dev->dev, "Bus powered up, waiting for link to come up\n");
+
+	dw_pcie_wait_for_link(pci);
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x010b, qcom_fixup_power);
+
 static struct platform_driver qcom_pcie_driver = {
 	.probe = qcom_pcie_probe,
 	.driver = {
-- 
2.29.2
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