[coreboot-gerrit] New patch to review for coreboot: a98772c Baytrail: Change PCIe root disable algorithm

[Stefan Reinauer]

Stefan Reinauer ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9219

-gerrit

commit a98772c4b87b3bb96dc20f6cccc2568de3bcb1f4
Author: Kenji Chen 
Date:   Fri Sep 12 02:10:53 2014 +0800

Baytrail: Change PCIe root disable algorithm

Disable Root Port0 only when there is no PCIe device
    present on any root port.

BUG=None
    TEST=Boot Rambi with PCIe installed/non-installed on RP0 to
    confirm the RP0 is correctly enabled/disabled. However, I still
    need someone to help check if RP0(no device) is still enabled
    if there is device on other RPs since since I have no devices
    having slots from RP1/2/3.

Change-Id: Iae552975250ed6f309c423b847621b8994172891
    Signed-off-by: Stefan Reinauer 
    Original-Commit-Id: c5cef0b7c2c146f0d46ed49b75fd2ec8369210ce
    Original-Change-Id: I7147569e78b2d1ecea070bc933773cdcae59f9e7
    Original-Signed-off-by: Kenji Chen 
    Original-Reviewed-on: https://chromium-review.googlesource.com/217791
    Original-Tested-by: Ted Kuo 
    Original-Reviewed-by: Aaron Durbin 
---
 src/soc/intel/baytrail/baytrail/pcie.h |  2 +-
 src/soc/intel/baytrail/pcie.c          | 39 ++++++++++++++++++++++++++++++++--
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/src/soc/intel/baytrail/baytrail/pcie.h b/src/soc/intel/baytrail/baytrail/pcie.h
index f76d3da..92ca3c8 100644
--- a/src/soc/intel/baytrail/baytrail/pcie.h
+++ b/src/soc/intel/baytrail/baytrail/pcie.h
@@ -98,5 +98,5 @@
 #define PHYCTL4			0x408
 # define SQDIS			(1 << 27)

-
+#define PCIE_ROOT_PORT_COUNT	4
 #endif /* _BAYTRAIL_PCIE_H_ */
diff --git a/src/soc/intel/baytrail/pcie.c b/src/soc/intel/baytrail/pcie.c
index 71b90de..f80a494 100644
--- a/src/soc/intel/baytrail/pcie.c
+++ b/src/soc/intel/baytrail/pcie.c
@@ -155,6 +155,35 @@ static void check_port_enabled(device_t dev)
    }
 }

+static u8 all_ports_no_dev_present(device_t dev)
+{
+	u8 func;
+	u8 temp = dev->path.pci.devfn;
+	u8 device_not_present = 1;
+	u8 data;
+
+	for (func = 1; func < PCIE_ROOT_PORT_COUNT; func++) {
+		dev->path.pci.devfn &= ~0x7;
+		dev->path.pci.devfn |= func;
+
+		/* is pcie device there */
+		if (pci_read_config32(dev, 0) == 0xFFFFFFFF)
+			continue;
+
+		data = pci_read_config8(dev, XCAP + 3) | (SI >> 24);
+		pci_write_config8(dev, XCAP + 3, data);
+
+		/* is any device present */
+		if ((pci_read_config32(dev, SLCTL_SLSTS) & PDS)) {
+			device_not_present = 0;
+			break;
+		}
+	}
+
+	dev->path.pci.devfn = temp;
+	return device_not_present;
+}
+
 static void check_device_present(device_t dev)
 {
    /* Set slot implemented. */
@@ -163,8 +192,14 @@ static void check_device_present(device_t dev)
    /* No device present. */
    if (!(pci_read_config32(dev, SLCTL_SLSTS) & PDS)) {
    	printk(BIOS_DEBUG, "No PCIe device present.\n");
-		reg_script_run_on_dev(dev, no_dev_behind_port);
-		dev->enabled = 0;
+		if (is_first_port(dev)) {
+			if (all_ports_no_dev_present(dev)) {
+				reg_script_run_on_dev(dev, no_dev_behind_port);
+				dev->enabled = 0;
+			}
+		} else {
+			dev->enabled = 0;
+		}
    } else if(!dev->enabled) {
    	/* Port is disabled, but device present. Disable link. */
    	pci_write_config32(dev, LCTL,