anx7447: Add proper mux setting for DP alt mode and DTS mode (CCD)

This patch must be with removing the external 100k pull up/down
resistors on the Aux P/Aux N lines which avoids the 3.3V DC bias
voltage adds 0.8V pulse of aux channel to turn on TCPC internal
P-MOSFET that causes the signal effect on CCD communication.

BUG=b:124410548
BRANCH=None
TEST=Connect external monitor,usb device or CCD cable to type-c port0
Each type-c device should work normally.

Signed-off-by: Xin Ji <xji@analogixsemi.com>
Signed-off-by: Jack Lai <jack.lai@intel.com>
Signed-off-by: Scott Collyer <scollyer@google.com>
Reviewed-by: Jett Rink <jettrink@chromium.org>
Reviewed-by: Zhuohao Lee <zhuohao@chromium.org>
Commit-Queue: Zhuohao Lee <zhuohao@chromium.org>
Tested-by: Zhuohao Lee <zhuohao@chromium.org>

Change-Id: Ic920c83232163292c3d6dbfce1b23a8e3a1c6b6e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1680664
Tested-by: Scott Collyer <scollyer@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Commit-Queue: Scott Collyer <scollyer@chromium.org>

3 files changed, 79 insertions, 2 deletions

diff --git a/driver/tcpm/anx7447.c b/driver/tcpm/anx7447.c
index d8c3cece6f..ebefe785cc 100644
--- a/driver/tcpm/anx7447.c
+++ b/driver/tcpm/anx7447.c
@@ -361,6 +361,15 @@ static int anx7447_init(int port)
 	reg |= ANX7447_REG_R_VCONN_PWR_PRT_INRUSH_TIME_2430US;
 	rv = tcpc_write(port, ANX7447_REG_ANALOG_CTRL_10, reg);
 
+#ifdef CONFIG_USB_PD_TCPM_MUX
+	/*
+	 * Run mux_set() here for considering CCD(Case-Closed Debugging) case
+	 * If this TCPC is not also the MUX then don't initialize to NONE
+	 */
+	if (!(usb_muxes[port].flags & USB_MUX_FLAG_NOT_TCPC))
+		rv |= anx7447_mux_set(port, TYPEC_MUX_NONE);
+#endif /* CONFIG_USB_PD_TCPM_MUX */
+
 	return rv;
 }
 
@@ -497,6 +506,41 @@ static int anx7447_mux_init(int port)
 	return anx7447_mux_set(port, TYPEC_MUX_NONE);
 }
 
+#ifdef CONFIG_USB_PD_TCPM_ANX7447_AUX_PU_PD
+static void anx7447_mux_safemode(int port, int on_off)
+{
+	int reg;
+
+	mux_read(port, ANX7447_REG_ANALOG_CTRL_9, &reg);
+
+	if (on_off)
+		reg |= ANX7447_REG_SAFE_MODE;
+	else
+		reg &= ~(ANX7447_REG_SAFE_MODE);
+
+	mux_write(port, ANX7447_REG_ANALOG_CTRL_9, reg);
+	CPRINTS("C%d set mux to safemode %s, reg = 0x%x",
+		port, (on_off) ? "on" : "off", reg);
+}
+
+static inline void anx7447_configure_aux_src(int port, int on_off)
+{
+	int reg;
+
+	mux_read(port, ANX7447_REG_ANALOG_CTRL_9, &reg);
+
+	if (on_off)
+		reg |= ANX7447_REG_R_AUX_RES_PULL_SRC;
+	else
+		reg &= ~(ANX7447_REG_R_AUX_RES_PULL_SRC);
+
+	mux_write(port, ANX7447_REG_ANALOG_CTRL_9, reg);
+
+	CPRINTS("C%d set aux_src to %s, reg = 0x%x",
+		port, (on_off) ? "on" : "off", reg);
+}
+#endif
+
 /*
  * Set mux.
  *
@@ -515,8 +559,8 @@ static int anx7447_mux_set(int port, mux_state_t mux_state)
 
 	cc_direction = mux_state & MUX_POLARITY_INVERTED;
 	mux_type = mux_state & TYPEC_MUX_DOCK;
-	CPRINTS("mux_state = 0x%x, mux_type = 0x%x", mux_state, mux_type);
-
+	CPRINTS("C%d mux_state = 0x%x, mux_type = 0x%x",
+		port, mux_state, mux_type);
 	if (cc_direction == 0) {
 		/* cc1 connection */
 		if (mux_type == TYPEC_MUX_DOCK) {
@@ -550,12 +594,32 @@ static int anx7447_mux_set(int port, mux_state_t mux_state)
 			sw_sel = 0x10;
 		}
 	}
+
+	/*
+	 * Once need to configure the Mux, should set the mux to safe mode
+	 * first. After the  mux configured, should set mux to normal mode.
+	 */
+#ifdef CONFIG_USB_PD_TCPM_ANX7447_AUX_PU_PD
+	anx7447_mux_safemode(port, 1);
+#endif
 	rv = mux_write(port, ANX7447_REG_TCPC_SWITCH_0, sw_sel);
 	rv |= mux_write(port, ANX7447_REG_TCPC_SWITCH_1, sw_sel);
 	rv |= mux_write(port, ANX7447_REG_TCPC_AUX_SWITCH, aux_sw);
 
 	mux[port].state = mux_state;
 
+#ifdef CONFIG_USB_PD_TCPM_ANX7447_AUX_PU_PD
+	/*
+	 * DP and Dock mode: after configured the Mux, change the Mux to
+	 * normal mode, otherwise: keep safe mode.
+	 */
+	if (mux_type != TYPEC_MUX_NONE) {
+		anx7447_configure_aux_src(port, 1);
+		anx7447_mux_safemode(port, 0);
+	} else
+		anx7447_configure_aux_src(port, 0);
+#endif
+
 	return rv;
 }
 
diff --git a/driver/tcpm/anx7447.h b/driver/tcpm/anx7447.h
index f4827180da..4da300884c 100644
--- a/driver/tcpm/anx7447.h
+++ b/driver/tcpm/anx7447.h
@@ -49,6 +49,10 @@
 #define ANX7447_REG_R_VCONN_PWR_PRT_INRUSH_TIME_1210US	0x30
 #define ANX7447_REG_R_VCONN_PWR_PRT_INRUSH_TIME_2430US	0x38
 
+#define ANX7447_REG_ANALOG_CTRL_9	0xA9
+#define ANX7447_REG_SAFE_MODE		0x80
+#define ANX7447_REG_R_AUX_RES_PULL_SRC	0x20
+
 /*
  * This section of defines are only required to support the config option
  * CONFIG_USB_PD_TCPM_ANX7447_OCM_ERASE_COMMAND.
diff --git a/include/config.h b/include/config.h
index 81de017ae3..93d2b8401d 100644
--- a/include/config.h
+++ b/include/config.h
@@ -3781,6 +3781,15 @@
 #undef CONFIG_USB_PD_TCPM_ANX7447_OCM_ERASE_COMMAND
 
 /*
+ * Use this config option to enable and internal pullup resistor on the AUX_N
+ * and internal pulldown resistor on the AUX_P line. Only use this config
+ * option if there are no external pu/pd resistors on these signals. This
+ * configuration should be used to avoid noise issues on the DDI1_AUX_N &
+ * DDI1_AUX_P signals (b/122873171)
+ */
+#undef CONFIG_USB_PD_TCPM_ANX7447_AUX_PU_PD
+
+/*
  * Use this option if the TCPC port controller supports the optional register
  * 18h CONFIG_STANDARD_OUTPUT to steer the high-speed muxes.
  */