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path: root/drivers/pci/pcie/ptm.c
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* PCI: Add PTM clock granularity informationBjorn Helgaas2016-08-25
| | | | | | | | | | | | | | | | | | | | | | | | The PTM Control register (PCIe r3.1, sec 7.32.3) contains an Effective Granularity field: This provides information relating to the expected accuracy of the PTM clock, but does not otherwise affect the PTM mechanism. Set the Effective Granularity based on the PTM Root and any intervening PTM Time Sources. This does not set Effective Granularity for Root Complex Integrated Endpoints because I don't know how to figure out clock granularity for them. The spec says: ... system software must set [Effective Granularity] to the value reported in the Local Clock Granularity field by the associated PTM Time Source. but I don't know how to identify the associated PTM Time Source. Normally it's the upstream bridge, but an integrated endpoint has no upstream bridge. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* PCI: Add pci_enable_ptm() for drivers to enable PTM on endpointsBjorn Helgaas2016-08-18
| | | | | | | | Add an pci_enable_ptm() interface so drivers can enable PTM. The PCI core enables PTM on PTM Roots and switches automatically, but we don't enable PTM on endpoints unless a driver requests it. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* PCI: Add Precision Time Measurement (PTM) supportJonathan Yong2016-08-15
Add Precision Time Measurement (PTM) support (see PCIe r3.1, sec 6.22). Enable PTM on PTM Root devices and switch ports. This does not enable PTM on endpoints. There currently are no PTM-capable devices on the market, but it is expected to be supported by the Intel Apollo Lake platform. [bhelgaas: complete rework] Signed-off-by: Jonathan Yong <jonathan.yong@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>