usbc: add enter_low_power_mode for retimer mux

BUG=b:139428185
BRANCH=none
TEST=verify mode is set correctly when switching devices

Change-Id: I3e40e0321cb1026180b7edc0bfe99439c13acafb
Signed-off-by: Denis Brockus <dbrockus@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1922062

3 files changed, 62 insertions, 6 deletions

diff --git a/driver/retimer/pi3dpx1207.c b/driver/retimer/pi3dpx1207.c
index f1f1e19b54..8d57dcb6ef 100644
--- a/driver/retimer/pi3dpx1207.c
+++ b/driver/retimer/pi3dpx1207.c
@@ -18,6 +18,9 @@
 /* Stack space is limited, so put the buffer somewhere else */
 static uint8_t buf[PI3DPX1207_NUM_REGISTERS];
 
+/**
+ * Local utility functions
+ */
 static int pi3dpx1207_i2c_write(int i2c_port,
 				uint16_t addr_flags,
 				uint8_t offset,
@@ -60,6 +63,32 @@ static int pi3dpx1207_i2c_write(int i2c_port,
 	return rv;
 }
 
+static void pi3dpx1207_shutoff_power(int port)
+{
+	const int gpio_enable		= usb_retimers[port].gpio_enable;
+	const int gpio_dp_enable	= usb_retimers[port].gpio_dp_enable;
+
+	gpio_or_ioex_set_level(gpio_enable, 0);
+	gpio_or_ioex_set_level(gpio_dp_enable, 0);
+}
+
+/**
+ * Driver interface code
+ */
+static int pi3dpx1207_init(int port)
+{
+	const int gpio_enable		= usb_retimers[port].gpio_enable;
+
+	gpio_or_ioex_set_level(gpio_enable, 1);
+	return EC_SUCCESS;
+}
+
+static int pi3dpx1207_enter_low_power_mode(int port)
+{
+	pi3dpx1207_shutoff_power(port);
+	return EC_SUCCESS;
+}
+
 static int pi3dpx1207_set_mux(int port, mux_state_t mux_state)
 {
 	int rv = EC_SUCCESS;
@@ -98,8 +127,7 @@ static int pi3dpx1207_set_mux(int port, mux_state_t mux_state)
 	}
 	/* Nothing enabled, power down the retimer */
 	else {
-		gpio_or_ioex_set_level(gpio_enable, 0);
-		gpio_or_ioex_set_level(gpio_dp_enable, 0);
+		pi3dpx1207_shutoff_power(port);
 		return EC_SUCCESS;
 	}
 
@@ -111,5 +139,7 @@ static int pi3dpx1207_set_mux(int port, mux_state_t mux_state)
 }
 
 const struct usb_retimer_driver pi3dpx1207_usb_retimer = {
+	.init = pi3dpx1207_init,
 	.set = pi3dpx1207_set_mux,
+	.enter_low_power_mode = pi3dpx1207_enter_low_power_mode,
 };
diff --git a/driver/usb_mux/usb_mux.c b/driver/usb_mux/usb_mux.c
index be150c8741..0a33aef948 100644
--- a/driver/usb_mux/usb_mux.c
+++ b/driver/usb_mux/usb_mux.c
@@ -41,10 +41,24 @@ static void enter_low_power_mode(int port)
 	/* Apply any low power customization if present */
 	if (mux->driver->enter_low_power_mode) {
 		res = mux->driver->enter_low_power_mode(port);
+		if (res) {
+			CPRINTS("Err: %s mux port(%d): %d",
+				__func__, port, res);
+			return;
+		}
+	}
 
-		if (res)
-			CPRINTS("Err: enter_low_power_mode mux port(%d): %d",
-				port, res);
+	if (IS_ENABLED(CONFIG_USBC_MUX_RETIMER)) {
+		const struct usb_retimer *retimer = &usb_retimers[port];
+
+		if (retimer->driver && retimer->driver->enter_low_power_mode) {
+			res = retimer->driver->enter_low_power_mode(port);
+			if (res) {
+				CPRINTS("Err: %s retimer port(%d): %d",
+					__func__, port, res);
+				return;
+			}
+		}
 	}
 }
 
@@ -121,7 +135,10 @@ void usb_mux_set(int port, enum typec_mux mux_mode,
 	exit_low_power_mode(port);
 
 	/* Configure superspeed lanes */
-	mux_state = polarity ? mux_mode | MUX_POLARITY_INVERTED : mux_mode;
+	mux_state = ((mux_mode != TYPEC_MUX_NONE) && polarity)
+			? mux_mode | MUX_POLARITY_INVERTED
+			: mux_mode;
+
 	res = mux->driver->set(port, mux_state);
 	if (res) {
 		CPRINTS("Err: set mux port(%d): %d", port, res);
diff --git a/include/usb_mux.h b/include/usb_mux.h
index 126e7da4fa..0a5a19a338 100644
--- a/include/usb_mux.h
+++ b/include/usb_mux.h
@@ -156,6 +156,15 @@ struct usb_retimer_driver {
 	int (*init)(int port);
 
 	/**
+	 * Put USB retimer in low power mode. This is called when the MUX
+	 * is put into low power mode).
+	 *
+	 * @param port usb port of redriver (not port_addr)
+	 * @return EC_SUCCESS on success, non-zero error code on failure.
+	 */
+	int (*enter_low_power_mode)(int port);
+
+	/**
 	 * Set USB retimer state.
 	 *
 	 * @param port usb port of retimer (not port_addr)