dm: pci: Add APIs to find next capability and extended capability
This introduces two new APIs dm_pci_find_next_capability() and
dm_pci_find_next_ext_capability() to get PCI capability address
and PCI express extended capability address for a given PCI device
starting from a given offset.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index da49c96e..0c52337 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -1344,26 +1344,14 @@
return dm_pci_bus_to_virt(dev, pci_bus_addr, flags, 0, MAP_NOCACHE);
}
-int dm_pci_find_capability(struct udevice *dev, int cap)
+static int _dm_pci_find_next_capability(struct udevice *dev, u8 pos, int cap)
{
- u16 status;
- u8 header_type;
int ttl = PCI_FIND_CAP_TTL;
u8 id;
u16 ent;
- u8 pos;
-
- dm_pci_read_config16(dev, PCI_STATUS, &status);
- if (!(status & PCI_STATUS_CAP_LIST))
- return 0;
-
- dm_pci_read_config8(dev, PCI_HEADER_TYPE, &header_type);
- if ((header_type & 0x7f) == PCI_HEADER_TYPE_CARDBUS)
- pos = PCI_CB_CAPABILITY_LIST;
- else
- pos = PCI_CAPABILITY_LIST;
dm_pci_read_config8(dev, pos, &pos);
+
while (ttl--) {
if (pos < PCI_STD_HEADER_SIZEOF)
break;
@@ -1381,7 +1369,32 @@
return 0;
}
-int dm_pci_find_ext_capability(struct udevice *dev, int cap)
+int dm_pci_find_next_capability(struct udevice *dev, u8 start, int cap)
+{
+ return _dm_pci_find_next_capability(dev, start + PCI_CAP_LIST_NEXT,
+ cap);
+}
+
+int dm_pci_find_capability(struct udevice *dev, int cap)
+{
+ u16 status;
+ u8 header_type;
+ u8 pos;
+
+ dm_pci_read_config16(dev, PCI_STATUS, &status);
+ if (!(status & PCI_STATUS_CAP_LIST))
+ return 0;
+
+ dm_pci_read_config8(dev, PCI_HEADER_TYPE, &header_type);
+ if ((header_type & 0x7f) == PCI_HEADER_TYPE_CARDBUS)
+ pos = PCI_CB_CAPABILITY_LIST;
+ else
+ pos = PCI_CAPABILITY_LIST;
+
+ return _dm_pci_find_next_capability(dev, pos, cap);
+}
+
+int dm_pci_find_next_ext_capability(struct udevice *dev, int start, int cap)
{
u32 header;
int ttl;
@@ -1390,6 +1403,9 @@
/* minimum 8 bytes per capability */
ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
+ if (start)
+ pos = start;
+
dm_pci_read_config32(dev, pos, &header);
/*
* If we have no capabilities, this is indicated by cap ID,
@@ -1412,6 +1428,11 @@
return 0;
}
+int dm_pci_find_ext_capability(struct udevice *dev, int cap)
+{
+ return dm_pci_find_next_ext_capability(dev, 0, cap);
+}
+
UCLASS_DRIVER(pci) = {
.id = UCLASS_PCI,
.name = "pci",
diff --git a/include/pci.h b/include/pci.h
index 938a839..785d7d2 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -1313,6 +1313,29 @@
void *dm_pci_map_bar(struct udevice *dev, int bar, int flags);
/**
+ * dm_pci_find_next_capability() - find a capability starting from an offset
+ *
+ * Tell if a device supports a given PCI capability. Returns the
+ * address of the requested capability structure within the device's
+ * PCI configuration space or 0 in case the device does not support it.
+ *
+ * Possible values for @cap:
+ *
+ * %PCI_CAP_ID_MSI Message Signalled Interrupts
+ * %PCI_CAP_ID_PCIX PCI-X
+ * %PCI_CAP_ID_EXP PCI Express
+ * %PCI_CAP_ID_MSIX MSI-X
+ *
+ * See PCI_CAP_ID_xxx for the complete capability ID codes.
+ *
+ * @dev: PCI device to query
+ * @start: offset to start from
+ * @cap: capability code
+ * @return: capability address or 0 if not supported
+ */
+int dm_pci_find_next_capability(struct udevice *dev, u8 start, int cap);
+
+/**
* dm_pci_find_capability() - find a capability
*
* Tell if a device supports a given PCI capability. Returns the
@@ -1335,6 +1358,31 @@
int dm_pci_find_capability(struct udevice *dev, int cap);
/**
+ * dm_pci_find_next_ext_capability() - find an extended capability
+ * starting from an offset
+ *
+ * Tell if a device supports a given PCI express extended capability.
+ * Returns the address of the requested extended capability structure
+ * within the device's PCI configuration space or 0 in case the device
+ * does not support it.
+ *
+ * Possible values for @cap:
+ *
+ * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
+ * %PCI_EXT_CAP_ID_VC Virtual Channel
+ * %PCI_EXT_CAP_ID_DSN Device Serial Number
+ * %PCI_EXT_CAP_ID_PWR Power Budgeting
+ *
+ * See PCI_EXT_CAP_ID_xxx for the complete extended capability ID codes.
+ *
+ * @dev: PCI device to query
+ * @start: offset to start from
+ * @cap: extended capability code
+ * @return: extended capability address or 0 if not supported
+ */
+int dm_pci_find_next_ext_capability(struct udevice *dev, int start, int cap);
+
+/**
* dm_pci_find_ext_capability() - find an extended capability
*
* Tell if a device supports a given PCI express extended capability.