From 7f822999e12a144e68c915194267108f8051cf9b Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 27 Jan 2012 10:55:14 -0800 Subject: [PATCH] PCI: pciehp: Add Disable/enable link functions Will use it during power off/on of slots Signed-off-by: Yinghai Lu Signed-off-by: Jesse Barnes --- drivers/pci/hotplug/pciehp_hpc.c | 36 ++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 4ebdc1de2cb4..db33688af588 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -352,6 +352,42 @@ int pciehp_check_link_status(struct controller *ctrl) return retval; } +static int __pciehp_link_set(struct controller *ctrl, bool enable) +{ + u16 lnk_ctrl; + int retval = 0; + + retval = pciehp_readw(ctrl, PCI_EXP_LNKCTL, &lnk_ctrl); + if (retval) { + ctrl_err(ctrl, "Cannot read LNKCTRL register\n"); + return retval; + } + + if (enable) + lnk_ctrl &= ~PCI_EXP_LNKCTL_LD; + else + lnk_ctrl |= PCI_EXP_LNKCTL_LD; + + retval = pciehp_writew(ctrl, PCI_EXP_LNKCTL, lnk_ctrl); + if (retval) { + ctrl_err(ctrl, "Cannot write LNKCTRL register\n"); + return retval; + } + ctrl_dbg(ctrl, "%s: lnk_ctrl = %x\n", __func__, lnk_ctrl); + + return retval; +} + +static int pciehp_link_enable(struct controller *ctrl) +{ + return __pciehp_link_set(ctrl, true); +} + +static int pciehp_link_disable(struct controller *ctrl) +{ + return __pciehp_link_set(ctrl, false); +} + int pciehp_get_attention_status(struct slot *slot, u8 *status) { struct controller *ctrl = slot->ctrl;