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.ossl...@gmail.com>
---
Changes in v2:
- Use kernel PCI_EXP macros for register offsets
drivers/pci/pci-uclass.c | 24 ++++++++++++++++++++++++
include/pci.h | 14 ++++++++++++++
2 files changed, 38 insertions(+)
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index 389aec15ce..c74ebf6a76 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -1494,6 +1494,30 @@ int dm_pci_find_ext_capability(struct udevice *dev, int
cap)
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",
diff --git a/include/pci.h b/include/pci.h
index 0aab438159..298d0d4355 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -466,6 +466,12 @@
#define PCI_EA_IS_64 0x00000002 /* 64-bit field flag */
#define PCI_EA_FIELD_MASK 0xfffffffc /* For Base & Max Offset */
+/* PCI Express capabilities */
+#define PCI_EXP_DEVCAP 4 /* Device capabilities */
+#define PCI_EXP_DEVCAP_FLR 0x10000000 /* Function Level Reset */
+#define PCI_EXP_DEVCTL 8 /* Device Control */
+#define PCI_EXP_DEVCTL_BCR_FLR 0x8000 /* Bridge Configuration Retry / FLR */
+
/* Include the ID list */
#include <pci_ids.h>
@@ -1426,6 +1432,14 @@ int dm_pci_find_next_ext_capability(struct udevice *dev,
int start, int cap);
*/
int dm_pci_find_ext_capability(struct udevice *dev, int cap);
+/**
+ * dm_pci_flr() - Perform FLR if the device suppoorts it
+ *
+ * @dev: PCI device to reset
+ * @return: 0 if OK, -ENOENT if FLR is not supported by dev
+ */
+int dm_pci_flr(struct udevice *dev);
+
#define dm_pci_virt_to_bus(dev, addr, flags) \
dm_pci_phys_to_bus(dev, (virt_to_phys(addr)), (flags))
#define dm_pci_bus_to_virt(dev, addr, flags, len, map_flags) \
--
2.17.1
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