tcpm: Call usb_mux board_init on exit from low power mode

PS8751 does not restore all register contents when resuming
from low power mode. This change makes tcpm call board_init
when it stops auto-toggling so that register contents can be
restored.

BUG=b:35585399
BRACH=none
TEST=On Snappy, the board_init funciton is called every time a device
is plugged in and register contents are restored.

Change-Id: I50c51334f43c02e3c4d8453e1e966bf6eb3ce769
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/454139
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

8 files changed, 38 insertions, 13 deletions

diff --git a/board/reef/board.c b/board/reef/board.c
index c0ba7c3667..c39a038aa4 100644
--- a/board/reef/board.c
+++ b/board/reef/board.c
@@ -279,6 +279,14 @@ const enum gpio_signal hibernate_wake_pins[] = {
 
 const int hibernate_wake_pins_used = ARRAY_SIZE(hibernate_wake_pins);
 
+static int ps8751_tune_mux(const struct usb_mux *mux)
+{
+	/* 0x98 sets lower EQ of DP port (4.5db) */
+	i2c_write8(NPCX_I2C_PORT0_1, 0x16, PS8751_REG_MUX_DP_EQ_CONFIGURATION,
+		   0x98);
+	return EC_SUCCESS;
+}
+
 struct usb_mux usb_muxes[CONFIG_USB_PD_PORT_COUNT] = {
 	{
 		.port_addr = USB_PD_PORT_ANX74XX,  /* don't care / unused */
@@ -289,6 +297,7 @@ struct usb_mux usb_muxes[CONFIG_USB_PD_PORT_COUNT] = {
 		.port_addr = USB_PD_PORT_PS8751,
 		.driver = &tcpci_tcpm_usb_mux_driver,
 		.hpd_update = &ps8751_tcpc_update_hpd_status,
+		.board_init = &ps8751_tune_mux,
 	}
 };
 
@@ -375,10 +384,6 @@ void board_tcpc_init(void)
 
 		mux->hpd_update(port, 0, 0);
 	}
-
-	/* 0x98 sets lower EQ of DP port (4.5db) */
-	i2c_write8(NPCX_I2C_PORT0_1, 0x16, PS8751_REG_MUX_DP_EQ_Configuration,
-		   0x98);
 }
 DECLARE_HOOK(HOOK_INIT, board_tcpc_init, HOOK_PRIO_INIT_I2C+1);
 
diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c
index 84c4ba9acd..1447dccc71 100644
--- a/common/usb_pd_protocol.c
+++ b/common/usb_pd_protocol.c
@@ -2954,6 +2954,13 @@ defined(CONFIG_CASE_CLOSED_DEBUG_EXTERNAL)
 				/* Anything else, keep toggling */
 				next_state = PD_STATE_DRP_AUTO_TOGGLE;
 
+			if (next_state != PD_STATE_DRP_AUTO_TOGGLE) {
+				tcpm_set_drp_toggle(port, 0);
+#ifdef CONFIG_USB_PD_TCPC_LOW_POWER
+				CPRINTS("TCPC p%d Exit Low Power Mode", port);
+#endif
+			}
+
 			if (next_state == PD_STATE_SNK_DISCONNECTED) {
 				tcpm_set_cc(port, TYPEC_CC_RD);
 				pd[port].power_role = PD_ROLE_SINK;
@@ -2963,7 +2970,7 @@ defined(CONFIG_CASE_CLOSED_DEBUG_EXTERNAL)
 				pd[port].power_role = PD_ROLE_SOURCE;
 				timeout = 2*MSEC;
 			} else {
-				tcpm_set_drp_toggle(port);
+				tcpm_set_drp_toggle(port, 1);
 				pd[port].flags |= PD_FLAGS_TCPC_DRP_TOGGLE;
 				timeout = -1;
 #ifdef CONFIG_USB_PD_TCPC_LOW_POWER
diff --git a/driver/tcpm/anx74xx.c b/driver/tcpm/anx74xx.c
index e3d7d081e7..128890a8dd 100644
--- a/driver/tcpm/anx74xx.c
+++ b/driver/tcpm/anx74xx.c
@@ -632,8 +632,11 @@ void anx74xx_handle_power_mode(int port, int mode)
 	}
 }
 
-static int anx74xx_tcpc_drp_toggle(int port)
+static int anx74xx_tcpc_drp_toggle(int port, int enable)
 {
+	if (!enable)
+		/* TODO: Switch to normal mode here (Issue 702277) */
+		return EC_SUCCESS;
 	anx74xx_handle_power_mode(port, ANX74XX_STANDBY_MODE);
 	return EC_SUCCESS;
 }
diff --git a/driver/tcpm/ps8751.h b/driver/tcpm/ps8751.h
index 0b91572c34..9dd922208a 100644
--- a/driver/tcpm/ps8751.h
+++ b/driver/tcpm/ps8751.h
@@ -18,7 +18,7 @@
 #define PS8751_REG_CTRL_1       0xD0
 #define PS8751_REG_CTRL_1_HPD   (1 << 0)
 #define PS8751_REG_CTRL_1_IRQ   (1 << 1)
-#define PS8751_REG_MUX_DP_EQ_Configuration	0xD3
+#define PS8751_REG_MUX_DP_EQ_CONFIGURATION	0xD3
 #define PS8751_REG_MUX_USB_C2SS_EQ		0xe7
 #define PS8751_REG_MUX_USB_C2SS_HS_THRESHOLD	0xe8
 
diff --git a/driver/tcpm/tcpci.c b/driver/tcpm/tcpci.c
index cbbed9c05e..8da8bdd532 100644
--- a/driver/tcpm/tcpci.c
+++ b/driver/tcpm/tcpci.c
@@ -127,10 +127,18 @@ int tcpci_tcpm_set_cc(int port, int pull)
 }
 
 #ifdef CONFIG_USB_PD_DUAL_ROLE_AUTO_TOGGLE
-static int tcpci_tcpc_drp_toggle(int port)
+static int tcpci_tcpc_drp_toggle(int port, int enable)
 {
 	int rv;
 
+	if (!enable) {
+#ifdef CONFIG_USB_PD_TCPC_LOW_POWER
+		struct usb_mux *mux = &usb_muxes[port];
+		if (mux->board_init)
+			return mux->board_init(mux);
+#endif
+		return EC_SUCCESS;
+	}
 	/* Set auto drp toggle */
 	rv = set_role_ctrl(port, 1, TYPEC_RP_USB, TYPEC_CC_OPEN);
 
@@ -507,7 +515,7 @@ const struct tcpm_drv tcpci_tcpm_drv = {
 	.tcpc_discharge_vbus	= &tcpci_tcpc_discharge_vbus,
 #endif
 #ifdef CONFIG_USB_PD_DUAL_ROLE_AUTO_TOGGLE
-	.drp_toggle	= &tcpci_tcpc_drp_toggle,
+	.drp_toggle		= &tcpci_tcpc_drp_toggle,
 #endif
 	.get_chip_info		= &tcpci_get_chip_info,
 };
diff --git a/driver/tcpm/tcpm.h b/driver/tcpm/tcpm.h
index 797a8c0dad..71af9361f9 100644
--- a/driver/tcpm/tcpm.h
+++ b/driver/tcpm/tcpm.h
@@ -143,9 +143,9 @@ static inline int tcpm_auto_toggle_supported(int port)
 	return !!tcpc_config[port].drv->drp_toggle;
 }
 
-static inline int tcpm_set_drp_toggle(int port)
+static inline int tcpm_set_drp_toggle(int port, int enable)
 {
-	return tcpc_config[port].drv->drp_toggle(port);
+	return tcpc_config[port].drv->drp_toggle(port, enable);
 }
 #endif
 
diff --git a/include/usb_mux.h b/include/usb_mux.h
index c9bd76ba21..5e1fb6945a 100644
--- a/include/usb_mux.h
+++ b/include/usb_mux.h
@@ -71,7 +71,8 @@ struct usb_mux {
 
 	/**
 	 * Board specific initialization for USB mux that is
-	 * called after mux->driver->init() function.
+	 * called after mux->driver->init() function and every time the port
+	 * leaves auto-toggle state.
 	 *
 	 * @param mux USB mux to tune
 	 * @return EC_SUCCESS on success, non-zero error code on failure.
diff --git a/include/usb_pd_tcpm.h b/include/usb_pd_tcpm.h
index c8526239d1..fe5d6232e6 100644
--- a/include/usb_pd_tcpm.h
+++ b/include/usb_pd_tcpm.h
@@ -192,10 +192,11 @@ struct tcpm_drv {
 	 * Enable TCPC auto DRP toggling.
 	 *
 	 * @param port Type-C port number
+	 * @param enable 1: Enable 0: Disable
 	 *
 	 * @return EC_SUCCESS or error
 	 */
-	int (*drp_toggle)(int port);
+	int (*drp_toggle)(int port, int enable);
 #endif
 
 	/**