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 ---
Changes in v2: - Use kernel PCI_EXP macros for register offsets Changes in v3: - none
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) \