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authorKane Chen <kane.chen@intel.com>2014-10-01 11:13:54 +0800
committerStefan Reinauer <stefan.reinauer@coreboot.org>2015-03-09 03:33:13 +0100
commit18cb1340f185150b9708257ba8024b6900706083 (patch)
tree0d567633540e19104711d664b44f144ba653ec25 /src/device
parent2c4aab3fd6cd7b357b8389c20a95a6ad59cc75a0 (diff)
downloadcoreboot-18cb1340f185150b9708257ba8024b6900706083.tar.xz
device/pciexp: Add support for PCIe CLK power management
Set PCIe "Enable Clock Power Management", if endpoint supports it. BUG=chrome-os-partner:31424 BRANCH=none TEST=build and boot on rambi, check Enable Clock Power Management in link control register is set properly Change-Id: Ie54110d1ef42184cfcf47c9fe4d735960aebe47f Signed-off-by: Kane Chen <kane.chen@intel.com> Reviewed-on: https://chromium-review.googlesource.com/220742 Reviewed-by: Duncan Laurie <dlaurie@chromium.org> [Edit commit message.] Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-on: http://review.coreboot.org/8447 Tested-by: build bot (Jenkins) Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com> Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/device')
-rw-r--r--src/device/Kconfig8
-rw-r--r--src/device/pciexp_device.c22
2 files changed, 30 insertions, 0 deletions
diff --git a/src/device/Kconfig b/src/device/Kconfig
index 91da02a193..42a68d296a 100644
--- a/src/device/Kconfig
+++ b/src/device/Kconfig
@@ -251,6 +251,14 @@ config PCIEXP_ASPM
help
Detect and enable ASPM on PCIe links.
+config PCIEXP_CLK_PM
+ prompt "Enable PCIe Clock Power Management"
+ bool
+ depends on PCIEXP_PLUGIN_SUPPORT
+ default n
+ help
+ Detect and enable Clock Power Management on PCIe.
+
config PCI_BUS_SEGN_BITS
int
default 0
diff --git a/src/device/pciexp_device.c b/src/device/pciexp_device.c
index 87aea672db..edb103d861 100644
--- a/src/device/pciexp_device.c
+++ b/src/device/pciexp_device.c
@@ -90,6 +90,23 @@ static void pciexp_enable_common_clock(device_t root, unsigned root_cap,
}
#endif /* CONFIG_PCIEXP_COMMON_CLOCK */
+#if CONFIG_PCIEXP_CLK_PM
+static void pciexp_enable_clock_power_pm(device_t endp, unsigned endp_cap)
+{
+ /* check if per port clk req is supported in device */
+ u32 endp_ca;
+ u16 lnkctl;
+ endp_ca = pci_read_config32(endp, endp_cap + PCI_EXP_LNKCAP);
+ if ((endp_ca & PCI_EXP_CLK_PM) == 0) {
+ printk(BIOS_INFO, "PCIE CLK PM is not supported by endpoint");
+ return;
+ }
+ lnkctl = pci_read_config16(endp, endp_cap + PCI_EXP_LNKCTL);
+ lnkctl = lnkctl | PCI_EXP_EN_CLK_PM;
+ pci_write_config16(endp, endp_cap + PCI_EXP_LNKCTL, lnkctl);
+}
+#endif /* CONFIG_PCIEXP_CLK_PM */
+
#if CONFIG_PCIEXP_ASPM
/*
* Determine the ASPM L0s or L1 exit latency for a link
@@ -200,6 +217,11 @@ static void pciexp_tune_dev(device_t dev)
pciexp_enable_common_clock(root, root_cap, dev, cap);
#endif
+#if CONFIG_PCIEXP_CLK_PM
+ /* Check if per port CLK req is supported by endpoint*/
+ pciexp_enable_clock_power_pm(dev, cap);
+#endif
+
#if CONFIG_PCIEXP_ASPM
/* Check for and enable ASPM */
enum aspm_type apmc = pciexp_enable_aspm(root, root_cap, dev, cap);