drivers: pci: add API to issue FLR on a PCI function if supported
Adds dm_pci_flr API that issues a Function Level reset on a PCI-e function,
if FLR is supported.
Signed-off-by: Alex Marginean <alexm.osslist@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index 389aec1..c74ebf6 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -1494,6 +1494,30 @@
return dm_pci_find_next_ext_capability(dev, 0, cap);
}
+int dm_pci_flr(struct udevice *dev)
+{
+ int pcie_off;
+ u32 cap;
+
+ /* look for PCI Express Capability */
+ pcie_off = dm_pci_find_capability(dev, PCI_CAP_ID_EXP);
+ if (!pcie_off)
+ return -ENOENT;
+
+ /* check FLR capability */
+ dm_pci_read_config32(dev, pcie_off + PCI_EXP_DEVCAP, &cap);
+ if (!(cap & PCI_EXP_DEVCAP_FLR))
+ return -ENOENT;
+
+ dm_pci_clrset_config16(dev, pcie_off + PCI_EXP_DEVCTL, 0,
+ PCI_EXP_DEVCTL_BCR_FLR);
+
+ /* wait 100ms, per PCI spec */
+ mdelay(100);
+
+ return 0;
+}
+
UCLASS_DRIVER(pci) = {
.id = UCLASS_PCI,
.name = "pci",