BB retimer: Refactor TBT retimer bits

For DFP, the following bits depend on the Discover Mode SOP
and SOP' response.
Bit 2: RE_TIMER_DRIVER
Bit 17: TBT_TYPE,
Bit 18: CABLE_TYPE,
Bit 20: TBT_ACTIVE_LINK_TRAINING
Bits 29-28: TBT_GEN_SUPPORT
Hence setting these bits accordingly in "retimer_set_state_dfp()"
function.
Ref: Burnside Bridge spec Table 13: Connection state register

BUG=b:152544514
BRANCH=None
TEST=Able to see Thunderbolt getting enumerated on the CPU console

Signed-off-by: Ayushee <ayushee.shah@intel.com>
Change-Id: I0172cd9c74ba37c0f3e87db55cbd58ebaeef5ebe
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2139281
Reviewed-by: Keith Short <keithshort@chromium.org>

1 files changed, 84 insertions, 53 deletions

diff --git a/driver/retimer/bb_retimer.c b/driver/retimer/bb_retimer.c
index 1314a4a0a8..45cbc8bf2a 100644
--- a/driver/retimer/bb_retimer.c
+++ b/driver/retimer/bb_retimer.c
@@ -114,9 +114,12 @@ static void bb_retimer_power_handle(const struct usb_mux *me, int on_off)
 }
 
 static void retimer_set_state_dfp(int port, mux_state_t mux_state,
-				  uint32_t *set_retimer_con,
-				  enum idh_ptype cable_type)
+				  uint32_t *set_retimer_con)
 {
+	union tbt_mode_resp_cable cable_resp;
+	union tbt_mode_resp_device dev_resp;
+	enum idh_ptype cable_type = get_usb_pd_cable_type(port);
+
 	if (mux_state & USB_PD_MUX_USB_ENABLED) {
 		/*
 		 * Bit 4: USB2_CONNECTION (ignored if BIT5=0).
@@ -143,6 +146,60 @@ static void retimer_set_state_dfp(int port, mux_state_t mux_state,
 	    (cable_type == IDH_PTYPE_ACABLE))
 		*set_retimer_con |= BB_RETIMER_ACTIVE_PASSIVE;
 
+	/* TODO: Bit 2: RE_TIMER_DRIVER for USB/DP/USB4 */
+
+	if (mux_state & USB_PD_MUX_TBT_COMPAT_ENABLED) {
+		cable_resp = get_cable_tbt_vdo(port);
+		dev_resp = get_dev_tbt_vdo(port);
+
+		/*
+		 * Bit 2: RE_TIMER_DRIVER
+		 * 0 - Re-driver
+		 * 1 - Re-timer
+		 *
+		 * If Alternate mode is Thunderbolt-Compat, RE_TIMER_DRIVER is
+		 * set according to Discover Mode SOP' response,
+		 * Bit 22: Retimer Type.
+		 */
+		if (cable_resp.retimer_type == USB_RETIMER)
+			*set_retimer_con |= BB_RETIMER_RE_TIMER_DRIVER;
+
+		/*
+		 * Bit 17: TBT_TYPE
+		 * 0 - Type-C to Type-C Cable
+		 * 1 - Type-C Legacy TBT Adapter
+		 */
+		if (dev_resp.tbt_adapter == TBT_ADAPTER_TBT2_LEGACY)
+			*set_retimer_con |= BB_RETIMER_TBT_TYPE;
+
+		/*
+		 * Bit 18: CABLE_TYPE
+		 * 0 - Electrical cable
+		 * 1 - Optical cable
+		 */
+		if (cable_resp.tbt_cable == TBT_CABLE_OPTICAL)
+			*set_retimer_con |= BB_RETIMER_TBT_CABLE_TYPE;
+
+		/*
+		 * Bit 20: TBT_ACTIVE_LINK_TRAINING
+		 * 0 - Active with bi-directional LSRX communication
+		 * 1 - Active with uni-directional LSRX communication
+		 * Set to "0" when passive cable plug
+		 */
+		if (cable_type == IDH_PTYPE_ACABLE &&
+		    cable_resp.lsrx_comm == UNIDIR_LSRX_COMM)
+			*set_retimer_con |= BB_RETIMER_TBT_ACTIVE_LINK_TRAINING;
+
+		/*
+		 * Bits 29-28: TBT_GEN_SUPPORT
+		 * 00b - 3rd generation TBT (10.3125 and 20.625Gb/s)
+		 * 01b - 4th generation TBT (10.00005Gb/s, 10.3125Gb/s,
+		 *                           20.0625Gb/s, 20.000Gb/s)
+		 * 10..11b - Reserved
+		 */
+		*set_retimer_con |= BB_RETIMER_TBT_CABLE_GENERATION(
+				       cable_resp.tbt_rounded);
+	}
 }
 
 static void retimer_set_state_ufp(mux_state_t mux_state,
@@ -165,13 +222,36 @@ static void retimer_set_state_ufp(mux_state_t mux_state,
 		 */
 		*set_retimer_con |= BB_RETIMER_USB_DATA_ROLE;
 	}
+
+	 /*
+	  * Bit 17: TBT_TYPE
+	  * 0 - Type-C to Type-C Cable
+	  * 1 - Type-C Legacy TBT Adapter
+	  * For UFP, TBT_TYPE = 0
+	  */
+
 	/*
 	 * TODO: b/157163664: Add the following bits:
 	 *
+	 * Bit 2: RE_TIMER_DRIVER:
+	 * Set according to b20:19 of enter USB.
+	 *
+	 * Bit 18: CABLE_TYPE:
+	 * For Thunderbolt-compat mode, set according to bit 21 of enter mode.
+	 * For USB/DP/USB4, set according to bits 20:19 of enter mode.
+	 *
+	 * Bit 20: TBT_ACTIVE_LINK_TRAINING:
+	 * For Thunderbolt-compat mode, set according to bit 23 of enter mode.
+	 * For USB, set to 0.
+	 *
 	 * Bit 22: ACTIVE/PASSIVE
 	 * For USB4, set according to bits 20:19 of enter USB SOP.
 	 * For thubderbolt-compat mode, set according to bit 24 of enter mode
 	 * sop.
+	 *
+	 * Bits 29-28: TBT_GEN_SUPPORT
+	 * For Thunderbolt-compat mode, set according to bits 20:19 of enter
+	 * mode.
 	 */
 }
 
@@ -184,8 +264,6 @@ static int retimer_set_state(const struct usb_mux *me, mux_state_t mux_state)
 	uint8_t dp_pin_mode;
 	int port = me->usb_port;
 	union tbt_mode_resp_cable cable_resp;
-	union tbt_mode_resp_device dev_resp;
-	enum idh_ptype cable_type = get_usb_pd_cable_type(port);
 
 	/*
 	 * Bit 0: DATA_CONNECTION_PRESENT
@@ -258,61 +336,15 @@ static int retimer_set_state(const struct usb_mux *me, mux_state_t mux_state)
 	if (mux_state & (USB_PD_MUX_TBT_COMPAT_ENABLED |
 			 USB_PD_MUX_USB4_ENABLED)) {
 		cable_resp = get_cable_tbt_vdo(port);
-		dev_resp = get_dev_tbt_vdo(port);
-
-		/*
-		 * Bit 2: RE_TIMER_DRIVER
-		 * 0 - Re-driver
-		 * 1 - Re-timer
-		 */
-		if (cable_resp.retimer_type == USB_RETIMER)
-			set_retimer_con |= BB_RETIMER_RE_TIMER_DRIVER;
 
 		/*
 		 * Bit 16: TBT_CONNECTION
 		 * 0 - TBT not configured
 		 * 1 - TBT configured
 		 */
-		if (mux_state & USB_PD_MUX_TBT_COMPAT_ENABLED) {
+		if (mux_state & USB_PD_MUX_TBT_COMPAT_ENABLED)
 			set_retimer_con |= BB_RETIMER_TBT_CONNECTION;
 
-			/*
-			 * Bit 17: TBT_TYPE
-			 * 0 - Type-C to Type-C Cable
-			 * 1 - Type-C Legacy TBT Adapter
-			 */
-			if (dev_resp.tbt_adapter == TBT_ADAPTER_TBT2_LEGACY)
-				set_retimer_con |= BB_RETIMER_TBT_TYPE;
-
-			/*
-			 * Bits 29-28: TBT_GEN_SUPPORT
-			 * 00b - 3rd generation TBT (10.3125 and 20.625Gb/s)
-			 * 01b - 4th generation TBT (10.00005Gb/s, 10.3125Gb/s,
-			 *                           20.0625Gb/s, 20.000Gb/s)
-			 * 10..11b - Reserved
-			 */
-			set_retimer_con |= BB_RETIMER_TBT_CABLE_GENERATION(
-					       cable_resp.tbt_rounded);
-		}
-
-		/*
-		 * Bit 18: CABLE_TYPE
-		 * 0 - Electrical cable
-		 * 1 - Optical cable
-		 */
-		if (cable_resp.tbt_cable == TBT_CABLE_OPTICAL)
-			set_retimer_con |= BB_RETIMER_TBT_CABLE_TYPE;
-
-		/*
-		 * Bit 20: TBT_ACTIVE_LINK_TRAINING
-		 * 0 - Active with bi-directional LSRX communication
-		 * 1 - Active with uni-directional LSRX communication
-		 * Set to "0" when passive cable plug
-		 */
-		if (cable_type == IDH_PTYPE_ACABLE &&
-		    cable_resp.lsrx_comm == UNIDIR_LSRX_COMM)
-			set_retimer_con |= BB_RETIMER_TBT_ACTIVE_LINK_TRAINING;
-
 		/*
 		 * Bit 23: USB4 Connection
 		 * 0 - USB4 not configured
@@ -334,8 +366,7 @@ static int retimer_set_state(const struct usb_mux *me, mux_state_t mux_state)
 	}
 
 	if (pd_get_data_role(port) == PD_ROLE_DFP)
-		retimer_set_state_dfp(port, mux_state, &set_retimer_con,
-				      cable_type);
+		retimer_set_state_dfp(port, mux_state, &set_retimer_con);
 	else
 		retimer_set_state_ufp(mux_state, &set_retimer_con);