soc/intel/tgl,mb/google/volteer: Add API for Type-C aux bias pads

TGL boards using the Type-C subsystem for USB Type-C ports without a
retimer attached may require a DC bias on the aux lines for certain
modes to work. This patch adds native coreboot support for programming
the IOM to handle this DC bias via a simple devicetree
setting. Previously a UPD was required to tell the FSP which GPIOs were
used for the pullup and pulldown biases, but the API for this UPD was
effectively undocumented.

BUG=b:174116646
TEST=Verified on volteer2 that a Type-C flash drive is enumerated
succesfully on all ports. Verified all major power flows (boot, reboot,
powerdown and S0ix/suspend) still work as expected.

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: I70e36a41e760f4a435511c147cc5744a77dbccc0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51649
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/src/soc/intel/common/block/include/intelblocks/tcss.h b/src/soc/intel/common/block/include/intelblocks/tcss.h
index 68e279ca2a..29093d1664 100644
--- a/src/soc/intel/common/block/include/intelblocks/tcss.h
+++ b/src/soc/intel/common/block/include/intelblocks/tcss.h
@@ -3,6 +3,8 @@
 #ifndef _TCSS_H_
 #define _TCSS_H_
 
+#include <intelblocks/gpio.h>
+
 /* PMC IPC related offsets and commands */
 #define PMC_IPC_USBC_CMD_ID		0xA7
 #define PMC_IPC_USBC_SUBCMD_ID		0x0
@@ -136,7 +138,17 @@ struct tcss_port_map {
 	uint8_t usb3_port; /* USB3 Port Number */
 };
 
-void tcss_configure(void);
+struct typec_aux_bias_pads {
+	gpio_t pad_auxn_dc;
+	gpio_t pad_auxp_dc;
+};
+
+/*
+ * 1) Initialize TCSS muxes to disconnected state
+ * 2) Configure GPIO pads to provide DC Bias on AUX signals
+ * 3) Detect DP-over-Type-C alternate mode
+ */
+void tcss_configure(const struct typec_aux_bias_pads pads[MAX_TYPE_C_PORTS]);
 
 /*
  * Mainboard method to setup any mux config needed for TCSS display operations.