This introduces two new APIs dm_pci_find_capability() and dm_pci_find_ext_capability() to get PCI capability address and PCI express extended capability address for a given PCI device.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
---
Changes in v2: - Mask header_type with 0x7f
drivers/pci/pci-uclass.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++ include/pci.h | 46 ++++++++++++++++++++++++++++++++ 2 files changed, 114 insertions(+)
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c index 5eb6841..e9671d9 100644 --- a/drivers/pci/pci-uclass.c +++ b/drivers/pci/pci-uclass.c @@ -1320,6 +1320,74 @@ void *dm_pci_map_bar(struct udevice *dev, int bar, int flags) return dm_pci_bus_to_virt(dev, pci_bus_addr, flags, 0, MAP_NOCACHE); }
+int dm_pci_find_capability(struct udevice *dev, 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; + pos &= ~3; + dm_pci_read_config16(dev, pos, &ent); + + id = ent & 0xff; + if (id == 0xff) + break; + if (id == cap) + return pos; + pos = (ent >> 8); + } + + return 0; +} + +int dm_pci_find_ext_capability(struct udevice *dev, int cap) +{ + u32 header; + int ttl; + int pos = PCI_CFG_SPACE_SIZE; + + /* minimum 8 bytes per capability */ + ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8; + + dm_pci_read_config32(dev, pos, &header); + /* + * If we have no capabilities, this is indicated by cap ID, + * cap version and next pointer all being 0. + */ + if (header == 0) + return 0; + + while (ttl--) { + if (PCI_EXT_CAP_ID(header) == cap) + return pos; + + pos = PCI_EXT_CAP_NEXT(header); + if (pos < PCI_CFG_SPACE_SIZE) + break; + + dm_pci_read_config32(dev, pos, &header); + } + + return 0; +} + UCLASS_DRIVER(pci) = { .id = UCLASS_PCI, .name = "pci", diff --git a/include/pci.h b/include/pci.h index 83a40a5..938a839 100644 --- a/include/pci.h +++ b/include/pci.h @@ -17,6 +17,7 @@ * Under PCI, each device has 256 bytes of configuration address space, * of which the first 64 bytes are standardized as follows: */ +#define PCI_STD_HEADER_SIZEOF 64 #define PCI_VENDOR_ID 0x00 /* 16 bits */ #define PCI_DEVICE_ID 0x02 /* 16 bits */ #define PCI_COMMAND 0x04 /* 16 bits */ @@ -1311,6 +1312,51 @@ pci_addr_t dm_pci_phys_to_bus(struct udevice *dev, phys_addr_t addr, */ void *dm_pci_map_bar(struct udevice *dev, int bar, int flags);
+/** + * dm_pci_find_capability() - find a capability + * + * 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 + * @cap: capability code + * @return: capability address or 0 if not supported + */ +int dm_pci_find_capability(struct udevice *dev, int cap); + +/** + * dm_pci_find_ext_capability() - find an extended capability + * + * 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 + * @cap: extended capability code + * @return: extended capability address or 0 if not supported + */ +int dm_pci_find_ext_capability(struct udevice *dev, int cap); + #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) \