[PATCH 1/2] drm/dp: add drm_dp_phy_name() for getting DP PHY name

[Jani Nikula <jani.nikula@intel.com>]

Add a helper for getting the DP PHY name. In the interest of caller
simplicity and to avoid allocations and passing in of buffers, duplicate
the const strings to return. It's a minor penalty to pay for simplicity
in all the call sites.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 21 +++++++++++++++++++++
 include/drm/drm_dp_helper.h     |  2 ++
 2 files changed, 23 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index ada0a1ff262d..2c36fad88781 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -314,6 +314,27 @@ void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
 }
 EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
 
+const char *drm_dp_phy_name(enum drm_dp_phy dp_phy)
+{
+	static const char * const phy_names[] = {
+		[DP_PHY_DPRX] = "DPRX",
+		[DP_PHY_LTTPR1] = "LTTPR 1",
+		[DP_PHY_LTTPR2] = "LTTPR 2",
+		[DP_PHY_LTTPR3] = "LTTPR 3",
+		[DP_PHY_LTTPR4] = "LTTPR 4",
+		[DP_PHY_LTTPR5] = "LTTPR 5",
+		[DP_PHY_LTTPR6] = "LTTPR 6",
+		[DP_PHY_LTTPR7] = "LTTPR 7",
+		[DP_PHY_LTTPR8] = "LTTPR 8",
+	};
+
+	if (dp_phy < 0 || dp_phy >= ARRAY_SIZE(phy_names))
+		return "<INVALID DP PHY>";
+
+	return phy_names[dp_phy];
+}
+EXPORT_SYMBOL(drm_dp_phy_name);
+
 void drm_dp_lttpr_link_train_clock_recovery_delay(void)
 {
 	usleep_range(100, 200);
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index afdf7f4183f9..39a249d99a51 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -2132,6 +2132,8 @@ bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
 				const struct drm_dp_desc *desc);
 int drm_dp_read_sink_count(struct drm_dp_aux *aux);
 
+const char *drm_dp_phy_name(enum drm_dp_phy dp_phy);
+
 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
 				  u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
-- 
2.30.2