diff options
| author | Bjorn Helgaas <bhelgaas@google.com> | 2020-12-15 15:11:09 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2020-12-15 15:11:09 -0600 |
| commit | 72b3a644bbe994add91249676d77c279b1d92376 (patch) | |
| tree | c63ecbd900f7254d4e0c6adbe7e65a8d6946ede5 /drivers/pci/pcie | |
| parent | ff163da95b0ce29ce5ce597a1e98b3e528e57750 (diff) | |
| parent | a697f072f5da8d75467be81bec918eb479405615 (diff) | |
Merge branch 'pci/ptm'
- Save/restore Precision Time Measurement Capability for suspend/resume
(David E. Box)
- Disable PTM during suspend to save power (David E. Box)
* pci/ptm:
PCI: Disable PTM during suspend to save power
PCI/PTM: Save/restore Precision Time Measurement Capability for suspend/resume
Diffstat (limited to 'drivers/pci/pcie')
| -rw-r--r-- | drivers/pci/pcie/ptm.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c index 357a454cafa0..95d4eef2c9e8 100644 --- a/drivers/pci/pcie/ptm.c +++ b/drivers/pci/pcie/ptm.c @@ -29,6 +29,64 @@ static void pci_ptm_info(struct pci_dev *dev) dev->ptm_root ? " (root)" : "", clock_desc); } +void pci_disable_ptm(struct pci_dev *dev) +{ + int ptm; + u16 ctrl; + + if (!pci_is_pcie(dev)) + return; + + ptm = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM); + if (!ptm) + return; + + pci_read_config_word(dev, ptm + PCI_PTM_CTRL, &ctrl); + ctrl &= ~(PCI_PTM_CTRL_ENABLE | PCI_PTM_CTRL_ROOT); + pci_write_config_word(dev, ptm + PCI_PTM_CTRL, ctrl); +} + +void pci_save_ptm_state(struct pci_dev *dev) +{ + int ptm; + struct pci_cap_saved_state *save_state; + u16 *cap; + + if (!pci_is_pcie(dev)) + return; + + ptm = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM); + if (!ptm) + return; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_PTM); + if (!save_state) { + pci_err(dev, "no suspend buffer for PTM\n"); + return; + } + + cap = (u16 *)&save_state->cap.data[0]; + pci_read_config_word(dev, ptm + PCI_PTM_CTRL, cap); +} + +void pci_restore_ptm_state(struct pci_dev *dev) +{ + struct pci_cap_saved_state *save_state; + int ptm; + u16 *cap; + + if (!pci_is_pcie(dev)) + return; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_PTM); + ptm = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM); + if (!save_state || !ptm) + return; + + cap = (u16 *)&save_state->cap.data[0]; + pci_write_config_word(dev, ptm + PCI_PTM_CTRL, *cap); +} + void pci_ptm_init(struct pci_dev *dev) { int pos; @@ -65,6 +123,8 @@ void pci_ptm_init(struct pci_dev *dev) if (!pos) return; + pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_PTM, sizeof(u16)); + pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap); local_clock = (cap & PCI_PTM_GRANULARITY_MASK) >> 8; |