thunderbolt: Check valid TMU configuration in tb_switch_tmu_configure()

Instead of at enable time we can do this already in
tb_switch_tmu_configure().
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/tb.c

@@ -282,9 +282,11 @@ static int tb_enable_tmu(struct tb_switch *sw)
 	 * highest accuracy.
 	 */
 	if (tb_switch_is_clx_enabled(sw, TB_CL1))
-		tb_switch_tmu_configure(sw, TB_SWITCH_TMU_RATE_NORMAL, true);
+		ret = tb_switch_tmu_configure(sw, TB_SWITCH_TMU_RATE_NORMAL, true);
 	else
-		tb_switch_tmu_configure(sw, TB_SWITCH_TMU_RATE_HIFI, false);
+		ret = tb_switch_tmu_configure(sw, TB_SWITCH_TMU_RATE_HIFI, false);
+	if (ret)
+		return ret;
 
 	/* If it is already enabled in correct mode, don't touch it */
 	if (tb_switch_tmu_is_enabled(sw))

drivers/thunderbolt/tb.h

@@ -987,9 +987,8 @@ int tb_switch_tmu_init(struct tb_switch *sw);
 int tb_switch_tmu_post_time(struct tb_switch *sw);
 int tb_switch_tmu_disable(struct tb_switch *sw);
 int tb_switch_tmu_enable(struct tb_switch *sw);
-void tb_switch_tmu_configure(struct tb_switch *sw,
-			     enum tb_switch_tmu_rate rate,
-			     bool unidirectional);
+int tb_switch_tmu_configure(struct tb_switch *sw, enum tb_switch_tmu_rate rate,
+			    bool unidirectional);
 /**
  * tb_switch_tmu_is_enabled() - Checks if the specified TMU mode is enabled
  * @sw: Router whose TMU mode to check

drivers/thunderbolt/tmu.c

@@ -648,9 +648,6 @@ int tb_switch_tmu_enable(struct tb_switch *sw)
 	bool unidirectional = sw->tmu.unidirectional_request;
 	int ret;
 
-	if (unidirectional && !sw->tmu.has_ucap)
-		return -EOPNOTSUPP;
-
 	/*
 	 * No need to enable TMU on devices that don't support CLx since on
 	 * these devices e.g. Alpine Ridge and earlier, the TMU mode HiFi
@@ -724,10 +721,16 @@ int tb_switch_tmu_enable(struct tb_switch *sw)
  *
  * Selects the rate of the TMU and directionality (uni-directional or
  * bi-directional). Must be called before tb_switch_tmu_enable().
+ *
+ * Returns %0 in success and negative errno otherwise.
  */
-void tb_switch_tmu_configure(struct tb_switch *sw,
-			     enum tb_switch_tmu_rate rate, bool unidirectional)
+int tb_switch_tmu_configure(struct tb_switch *sw, enum tb_switch_tmu_rate rate,
+			    bool unidirectional)
 {
+	if (unidirectional && !sw->tmu.has_ucap)
+		return -EINVAL;
+
 	sw->tmu.unidirectional_request = unidirectional;
 	sw->tmu.rate_request = rate;
+	return 0;
 }