[PATCH 3/4] thunderbolt: Add helpers to check if CL states are enabled on port

[Mika Westerberg <mika.westerberg@linux.intel.com>]

We will need these when enabling lane margining support.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/thunderbolt/switch.c | 23 +++++++++++++++++++++++
 drivers/thunderbolt/tb.h     |  7 +++++++
 2 files changed, 30 insertions(+)

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index deefc92c7c60..6b90bacb622e 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -1335,6 +1335,29 @@ static int tb_port_clx_enable(struct tb_port *port, enum tb_clx clx)
 	return __tb_port_clx_set(port, clx, true);
 }
 
+/**
+ * tb_port_is_clx_enabled() - Is given CL state enabled
+ * @port: USB4 port to check
+ * @clx: CL state to check
+ *
+ * Returns true if given CL state is enabled for @port.
+ */
+bool tb_port_is_clx_enabled(struct tb_port *port, enum tb_clx clx)
+{
+	u32 phy, mask = LANE_ADP_CS_1_CL0S_ENABLE | LANE_ADP_CS_1_CL1_ENABLE;
+	int ret;
+
+	if (!tb_port_clx_supported(port, clx))
+		return false;
+
+	ret = tb_port_read(port, &phy, TB_CFG_PORT,
+			   port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return false;
+
+	return (phy & mask) == mask;
+}
+
 static int tb_port_start_lane_initialization(struct tb_port *port)
 {
 	int ret;
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 8291cabd2e92..2154b59c39ec 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -1035,6 +1035,13 @@ void tb_port_lane_bonding_disable(struct tb_port *port);
 int tb_port_wait_for_link_width(struct tb_port *port, int width,
 				int timeout_msec);
 int tb_port_update_credits(struct tb_port *port);
+bool tb_port_is_clx_enabled(struct tb_port *port, enum tb_clx clx);
+
+static inline bool tb_port_are_clx_enabled(struct tb_port *port)
+{
+	return tb_port_is_clx_enabled(port, TB_CL1) ||
+	       tb_port_is_clx_enabled(port, TB_CL2);
+}
 
 int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec);
 int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap);
-- 
2.35.1