thunderbolt: Add CL1 support for USB4 and Titan Ridge routers

In this patch we add support for a second low power state of the link: CL1.
Low power states (called collectively CLx) are used to reduce
transmitter and receiver power when a high-speed lane is idle.
We enable it, if both sides of the link support it,
and only for the first hop router (i.e. the first device that connected
to the host router). This is needed for better thermal management.

Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

1 files changed, 46 insertions, 43 deletions

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index e584077b2f4f..244f8cd38b25 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -3133,10 +3133,12 @@ void tb_switch_suspend(struct tb_switch *sw, bool runtime)
 	/*
 	 * Actually only needed for Titan Ridge but for simplicity can be
 	 * done for USB4 device too as CLx is re-enabled at resume.
+	 * CL0s and CL1 are enabled and supported together.
 	 */
-	if (tb_switch_is_clx_enabled(sw)) {
-		if (tb_switch_disable_clx(sw, TB_CL0S))
-			tb_sw_warn(sw, "failed to disable CLx on upstream port\n");
+	if (tb_switch_is_clx_enabled(sw, TB_CL1)) {
+		if (tb_switch_disable_clx(sw, TB_CL1))
+			tb_sw_warn(sw, "failed to disable %s on upstream port\n",
+				   tb_switch_clx_name(TB_CL1));
 	}
 
 	err = tb_plug_events_active(sw, false);
@@ -3428,13 +3430,12 @@ static bool tb_port_clx_supported(struct tb_port *port, enum tb_clx clx)
 	}
 
 	switch (clx) {
-	case TB_CL0S:
-		/* CL0s support requires also CL1 support */
+	case TB_CL1:
+		/* CL0s and CL1 are enabled and supported together */
 		mask = LANE_ADP_CS_0_CL0S_SUPPORT | LANE_ADP_CS_0_CL1_SUPPORT;
 		break;
 
-	/* For now we support only CL0s. Not CL1, CL2 */
-	case TB_CL1:
+	/* For now we support only CL0s and CL1. Not CL2 */
 	case TB_CL2:
 	default:
 		return false;
@@ -3448,18 +3449,18 @@ static bool tb_port_clx_supported(struct tb_port *port, enum tb_clx clx)
 	return !!(val & mask);
 }
 
-static inline bool tb_port_cl0s_supported(struct tb_port *port)
-{
-	return tb_port_clx_supported(port, TB_CL0S);
-}
-
-static int __tb_port_cl0s_set(struct tb_port *port, bool enable)
+static int __tb_port_clx_set(struct tb_port *port, enum tb_clx clx, bool enable)
 {
 	u32 phy, mask;
 	int ret;
 
-	/* To enable CL0s also required to enable CL1 */
-	mask = LANE_ADP_CS_1_CL0S_ENABLE | LANE_ADP_CS_1_CL1_ENABLE;
+	/* CL0s and CL1 are enabled and supported together */
+	if (clx == TB_CL1)
+		mask = LANE_ADP_CS_1_CL0S_ENABLE | LANE_ADP_CS_1_CL1_ENABLE;
+	else
+		/* For now we support only CL0s and CL1. Not CL2 */
+		return -EOPNOTSUPP;
+
 	ret = tb_port_read(port, &phy, TB_CFG_PORT,
 			   port->cap_phy + LANE_ADP_CS_1, 1);
 	if (ret)
@@ -3474,20 +3475,20 @@ static int __tb_port_cl0s_set(struct tb_port *port, bool enable)
 			     port->cap_phy + LANE_ADP_CS_1, 1);
 }
 
-static int tb_port_cl0s_disable(struct tb_port *port)
+static int tb_port_clx_disable(struct tb_port *port, enum tb_clx clx)
 {
-	return __tb_port_cl0s_set(port, false);
+	return __tb_port_clx_set(port, clx, false);
 }
 
-static int tb_port_cl0s_enable(struct tb_port *port)
+static int tb_port_clx_enable(struct tb_port *port, enum tb_clx clx)
 {
-	return __tb_port_cl0s_set(port, true);
+	return __tb_port_clx_set(port, clx, true);
 }
 
-static int tb_switch_enable_cl0s(struct tb_switch *sw)
+static int __tb_switch_enable_clx(struct tb_switch *sw, enum tb_clx clx)
 {
 	struct tb_switch *parent = tb_switch_parent(sw);
-	bool up_cl0s_support, down_cl0s_support;
+	bool up_clx_support, down_clx_support;
 	struct tb_port *up, *down;
 	int ret;
 
@@ -3512,37 +3513,37 @@ static int tb_switch_enable_cl0s(struct tb_switch *sw)
 	up = tb_upstream_port(sw);
 	down = tb_port_at(tb_route(sw), parent);
 
-	up_cl0s_support = tb_port_cl0s_supported(up);
-	down_cl0s_support = tb_port_cl0s_supported(down);
+	up_clx_support = tb_port_clx_supported(up, clx);
+	down_clx_support = tb_port_clx_supported(down, clx);
 
-	tb_port_dbg(up, "CL0s %ssupported\n",
-		    up_cl0s_support ? "" : "not ");
-	tb_port_dbg(down, "CL0s %ssupported\n",
-		    down_cl0s_support ? "" : "not ");
+	tb_port_dbg(up, "%s %ssupported\n", tb_switch_clx_name(clx),
+		    up_clx_support ? "" : "not ");
+	tb_port_dbg(down, "%s %ssupported\n", tb_switch_clx_name(clx),
+		    down_clx_support ? "" : "not ");
 
-	if (!up_cl0s_support || !down_cl0s_support)
+	if (!up_clx_support || !down_clx_support)
 		return -EOPNOTSUPP;
 
-	ret = tb_port_cl0s_enable(up);
+	ret = tb_port_clx_enable(up, clx);
 	if (ret)
 		return ret;
 
-	ret = tb_port_cl0s_enable(down);
+	ret = tb_port_clx_enable(down, clx);
 	if (ret) {
-		tb_port_cl0s_disable(up);
+		tb_port_clx_disable(up, clx);
 		return ret;
 	}
 
 	ret = tb_switch_mask_clx_objections(sw);
 	if (ret) {
-		tb_port_cl0s_disable(up);
-		tb_port_cl0s_disable(down);
+		tb_port_clx_disable(up, clx);
+		tb_port_clx_disable(down, clx);
 		return ret;
 	}
 
-	sw->clx = TB_CL0S;
+	sw->clx = clx;
 
-	tb_port_dbg(up, "CL0s enabled\n");
+	tb_port_dbg(up, "%s enabled\n", tb_switch_clx_name(clx));
 	return 0;
 }
 
@@ -3575,15 +3576,16 @@ int tb_switch_enable_clx(struct tb_switch *sw, enum tb_clx clx)
 		return 0;
 
 	switch (clx) {
-	case TB_CL0S:
-		return tb_switch_enable_cl0s(sw);
+	case TB_CL1:
+		/* CL0s and CL1 are enabled and supported together */
+		return __tb_switch_enable_clx(sw, clx);
 
 	default:
 		return -EOPNOTSUPP;
 	}
 }
 
-static int tb_switch_disable_cl0s(struct tb_switch *sw)
+static int __tb_switch_disable_clx(struct tb_switch *sw, enum tb_clx clx)
 {
 	struct tb_switch *parent = tb_switch_parent(sw);
 	struct tb_port *up, *down;
@@ -3605,17 +3607,17 @@ static int tb_switch_disable_cl0s(struct tb_switch *sw)
 
 	up = tb_upstream_port(sw);
 	down = tb_port_at(tb_route(sw), parent);
-	ret = tb_port_cl0s_disable(up);
+	ret = tb_port_clx_disable(up, clx);
 	if (ret)
 		return ret;
 
-	ret = tb_port_cl0s_disable(down);
+	ret = tb_port_clx_disable(down, clx);
 	if (ret)
 		return ret;
 
 	sw->clx = TB_CLX_DISABLE;
 
-	tb_port_dbg(up, "CL0s disabled\n");
+	tb_port_dbg(up, "%s disabled\n", tb_switch_clx_name(clx));
 	return 0;
 }
 
@@ -3632,8 +3634,9 @@ int tb_switch_disable_clx(struct tb_switch *sw, enum tb_clx clx)
 		return 0;
 
 	switch (clx) {
-	case TB_CL0S:
-		return tb_switch_disable_cl0s(sw);
+	case TB_CL1:
+		/* CL0s and CL1 are enabled and supported together */
+		return __tb_switch_disable_clx(sw, clx);
 
 	default:
 		return -EOPNOTSUPP;