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, 24 insertions, 22 deletions

diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 4602c69913fa..3882b6eb9f51 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -13,6 +13,7 @@
 #include <linux/pci.h>
 #include <linux/thunderbolt.h>
 #include <linux/uuid.h>
+#include <linux/bitfield.h>
 
 #include "tb_regs.h"
 #include "ctl.h"
@@ -111,7 +112,7 @@ struct tb_switch_tmu {
 
 enum tb_clx {
 	TB_CLX_DISABLE,
-	TB_CL0S,
+	/* CL0s and CL1 are enabled and supported together */
 	TB_CL1,
 	TB_CL2,
 };
@@ -934,45 +935,46 @@ void tb_switch_tmu_configure(struct tb_switch *sw,
 			     enum tb_switch_tmu_rate rate,
 			     bool unidirectional);
 /**
- * tb_switch_tmu_hifi_is_enabled() - Checks if the specified TMU mode is enabled
+ * tb_switch_tmu_is_enabled() - Checks if the specified TMU mode is enabled
  * @sw: Router whose TMU mode to check
  * @unidirectional: If uni-directional (bi-directional otherwise)
  *
  * Return true if hardware TMU configuration matches the one passed in
- * as parameter. That is HiFi and either uni-directional or bi-directional.
+ * as parameter. That is HiFi/Normal and either uni-directional or bi-directional.
  */
-static inline bool tb_switch_tmu_hifi_is_enabled(const struct tb_switch *sw,
-						 bool unidirectional)
+static inline bool tb_switch_tmu_is_enabled(const struct tb_switch *sw,
+					    bool unidirectional)
 {
-	return sw->tmu.rate == TB_SWITCH_TMU_RATE_HIFI &&
+	return sw->tmu.rate == sw->tmu.rate_request &&
 	       sw->tmu.unidirectional == unidirectional;
 }
 
+static inline const char *tb_switch_clx_name(enum tb_clx clx)
+{
+	switch (clx) {
+	/* CL0s and CL1 are enabled and supported together */
+	case TB_CL1:
+		return "CL0s/CL1";
+	default:
+		return "unknown";
+	}
+}
+
 int tb_switch_enable_clx(struct tb_switch *sw, enum tb_clx clx);
 int tb_switch_disable_clx(struct tb_switch *sw, enum tb_clx clx);
 
 /**
  * tb_switch_is_clx_enabled() - Checks if the CLx is enabled
- * @sw: Router to check the CLx state for
- *
- * Checks if the CLx is enabled on the router upstream link.
- * Not applicable for a host router.
- */
-static inline bool tb_switch_is_clx_enabled(const struct tb_switch *sw)
-{
-	return sw->clx != TB_CLX_DISABLE;
-}
-
-/**
- * tb_switch_is_cl0s_enabled() - Checks if the CL0s is enabled
- * @sw: Router to check for the CL0s
+ * @sw: Router to check for the CLx
+ * @clx: The CLx state to check for
  *
- * Checks if the CL0s is enabled on the router upstream link.
+ * Checks if the specified CLx is enabled on the router upstream link.
  * Not applicable for a host router.
  */
-static inline bool tb_switch_is_cl0s_enabled(const struct tb_switch *sw)
+static inline bool tb_switch_is_clx_enabled(const struct tb_switch *sw,
+					    enum tb_clx clx)
 {
-	return sw->clx == TB_CL0S;
+	return sw->clx == clx;
 }
 
 /**