diff options
Diffstat (limited to 'drivers/pci/pcie')
| -rw-r--r-- | drivers/pci/pcie/ptm.c | 71 |
1 files changed, 57 insertions, 14 deletions
diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c index ba1d50c965fa..70a28b74e721 100644 --- a/drivers/pci/pcie/ptm.c +++ b/drivers/pci/pcie/ptm.c @@ -29,7 +29,7 @@ static void pci_ptm_info(struct pci_dev *dev) dev->ptm_root ? " (root)" : "", clock_desc); } -void pci_disable_ptm(struct pci_dev *dev) +static void __pci_disable_ptm(struct pci_dev *dev) { u16 ptm = dev->ptm_cap; u16 ctrl; @@ -42,6 +42,21 @@ void pci_disable_ptm(struct pci_dev *dev) pci_write_config_word(dev, ptm + PCI_PTM_CTRL, ctrl); } +/** + * pci_disable_ptm() - Disable Precision Time Measurement + * @dev: PCI device + * + * Disable Precision Time Measurement for @dev. + */ +void pci_disable_ptm(struct pci_dev *dev) +{ + if (dev->ptm_enabled) { + __pci_disable_ptm(dev); + dev->ptm_enabled = 0; + } +} +EXPORT_SYMBOL(pci_disable_ptm); + void pci_save_ptm_state(struct pci_dev *dev) { u16 ptm = dev->ptm_cap; @@ -151,18 +166,8 @@ void pci_ptm_init(struct pci_dev *dev) pci_enable_ptm(dev, NULL); } -/** - * pci_enable_ptm() - Enable Precision Time Measurement - * @dev: PCI device - * @granularity: pointer to return granularity - * - * Enable Precision Time Measurement for @dev. If successful and - * @granularity is non-NULL, return the Effective Granularity. - * - * Return: zero if successful, or -EINVAL if @dev lacks a PTM Capability or - * is not a PTM Root and lacks an upstream path of PTM-enabled devices. - */ -int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) +/* Enable PTM in the Control register if possible */ +static int __pci_enable_ptm(struct pci_dev *dev) { u16 ptm = dev->ptm_cap; struct pci_dev *ups; @@ -191,8 +196,29 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) ctrl |= PCI_PTM_CTRL_ROOT; pci_write_config_dword(dev, ptm + PCI_PTM_CTRL, ctrl); - dev->ptm_enabled = 1; + return 0; +} +/** + * pci_enable_ptm() - Enable Precision Time Measurement + * @dev: PCI device + * @granularity: pointer to return granularity + * + * Enable Precision Time Measurement for @dev. If successful and + * @granularity is non-NULL, return the Effective Granularity. + * + * Return: zero if successful, or -EINVAL if @dev lacks a PTM Capability or + * is not a PTM Root and lacks an upstream path of PTM-enabled devices. + */ +int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) +{ + int rc; + + rc = __pci_enable_ptm(dev); + if (rc) + return rc; + + dev->ptm_enabled = 1; pci_ptm_info(dev); if (granularity) @@ -201,6 +227,23 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) } EXPORT_SYMBOL(pci_enable_ptm); +/* + * Disable PTM, but preserve dev->ptm_enabled so we silently re-enable it on + * resume if necessary. + */ +void pci_suspend_ptm(struct pci_dev *dev) +{ + if (dev->ptm_enabled) + __pci_disable_ptm(dev); +} + +/* If PTM was enabled before suspend, re-enable it when resuming */ +void pci_resume_ptm(struct pci_dev *dev) +{ + if (dev->ptm_enabled) + __pci_enable_ptm(dev); +} + bool pcie_ptm_enabled(struct pci_dev *dev) { if (!dev) |