baytrail: HDA function disable workaround
Parts of the audio path are common between the HDA and LPE.
However, those parts are power-controlled by the D-state of
the HDA device. Therefore, one cannot put the HDA into D3Hot
because those audio paths will be shutdown.
BUG=chrome-os-partner:22871
BRANCH=None
TEST=Built and booted through depthcharge. Disabling HDA still
causes a shutdown when performing warm reset, however I
was able to verify the magic sequence was being performed.
Change-Id: I3b01356d85a4b7b902bd896b8eb9e7bc509fcc42
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/175491
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/4926
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
diff --git a/src/soc/intel/baytrail/southcluster.c b/src/soc/intel/baytrail/southcluster.c
index 42349fa..c71ab7e 100644
--- a/src/soc/intel/baytrail/southcluster.c
+++ b/src/soc/intel/baytrail/southcluster.c
@@ -238,10 +238,37 @@
pci_write_config8(dev, offset + 4, reg8);
}
+/* Parts of the audio subsystem are powered by the HDA device. Therefore, one
+ * cannot put HDA into D3Hot. Instead perform this workaround to make some of
+ * the audio paths work for LPE audio. */
+static void hda_work_around(device_t dev)
+{
+ unsigned long gctl = TEMP_BASE_ADDRESS + 0x8;
+
+ /* Need to set magic register 0x43 to 0xd7 in config space. */
+ pci_write_config8(dev, 0x43, 0xd7);
+
+ /* Need to set bit 0 of GCTL to take the device out of reset. However,
+ * that requires setting up the 64-bit BAR. */
+ pci_write_config32(dev, PCI_BASE_ADDRESS_0, TEMP_BASE_ADDRESS);
+ pci_write_config32(dev, PCI_BASE_ADDRESS_1, 0);
+ pci_write_config8(dev, PCI_COMMAND, PCI_COMMAND_MEMORY);
+ write32(gctl, read32(gctl) | 0x1);
+ pci_write_config8(dev, PCI_COMMAND, 0);
+ pci_write_config32(dev, PCI_BASE_ADDRESS_0, 0);
+}
+
static int place_device_in_d3hot(device_t dev)
{
unsigned offset;
+ /* Parts of the HDA block are used for LPE audio as well.
+ * Therefore assume the HDA will never be put into D3Hot. */
+ if (dev->path.pci.devfn == PCI_DEVFN(HDA_DEV, HDA_FUNC)) {
+ hda_work_around(dev);
+ return 0;
+ }
+
offset = pci_find_capability(dev, PCI_CAP_ID_PM);
if (offset != 0) {