Re: [PATCH 07/14] drm: bridge: icn6211: Add DSI lane count DT property parsing

Marek Vasut <marex@xxxxxxx> · Wed, 16 Feb 2022 21:24:36 +0100

On 2/3/22 13:13, Maxime Ripard wrote:
On Fri, Jan 14, 2022 at 04:48:31AM +0100, Marek Vasut wrote:
The driver currently hard-codes DSI lane count to two, however the chip
is capable of operating in 1..4 DSI lanes mode. Parse 'data-lanes' DT
property and program the result into DSI_CTRL register.

Signed-off-by: Marek Vasut <marex@xxxxxxx>
Cc: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
Cc: Robert Foss <robert.foss@xxxxxxxxxx>
Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
To: dri-devel@xxxxxxxxxxxxxxxxxxxxx
---
  drivers/gpu/drm/bridge/chipone-icn6211.c | 35 ++++++++++++++++++++----
  1 file changed, 29 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c
index 3ad082c1d2bfd..400a566026ab4 100644
--- a/drivers/gpu/drm/bridge/chipone-icn6211.c
+++ b/drivers/gpu/drm/bridge/chipone-icn6211.c
@@ -135,10 +135,12 @@ struct chipone {
  	struct device *dev;
  	struct drm_bridge bridge;
  	struct drm_bridge *panel_bridge;
+	struct device_node *host_node;
  	struct gpio_desc *enable_gpio;
  	struct regulator *vdd1;
  	struct regulator *vdd2;
  	struct regulator *vdd3;
+	int dsi_lanes;
  };
  
  static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge)
@@ -235,6 +237,11 @@ static void chipone_atomic_enable(struct drm_bridge *bridge,
  	/* dsi specific sequence */
  	ICN6211_DSI(icn, SYNC_EVENT_DLY, 0x80);
  	ICN6211_DSI(icn, HFP_MIN, hfp & 0xff);
+
+	/* DSI data lane count */
+	ICN6211_DSI(icn, DSI_CTRL,
+		    DSI_CTRL_UNKNOWN | DSI_CTRL_DSI_LANES(icn->dsi_lanes - 1));
+
  	ICN6211_DSI(icn, MIPI_PD_CK_LANE, 0xa0);
  	ICN6211_DSI(icn, PLL_CTRL(12), 0xff);
  
@@ -354,6 +361,8 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = {
  static int chipone_parse_dt(struct chipone *icn)
  {
  	struct device *dev = icn->dev;
+	struct drm_bridge *panel_bridge;
+	struct device_node *endpoint;
  	struct drm_panel *panel;
  	int ret;
  
@@ -390,13 +399,26 @@ static int chipone_parse_dt(struct chipone *icn)
  		return PTR_ERR(icn->enable_gpio);
  	}
  
-	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
-	if (ret)
+	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
+	icn->dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
+	icn->host_node = of_graph_get_remote_port_parent(endpoint);
+	of_node_put(endpoint);
+
+	if (icn->dsi_lanes < 0 || icn->dsi_lanes > 4)
+		return -EINVAL;
+	if (!icn->host_node)
+		return -ENODEV;
+
+	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, &panel_bridge);
+	if (ret < 0)
  		return ret;
+	if (panel) {
+		panel_bridge = devm_drm_panel_bridge_add(dev, panel);
+		if (IS_ERR(panel_bridge))
+			return PTR_ERR(panel_bridge);
+	}

-	icn->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
-	if (IS_ERR(icn->panel_bridge))
-		return PTR_ERR(icn->panel_bridge);
+	icn->panel_bridge = panel_bridge;

It looks like you're doing more than what you said in the commit log
here? There's at least a change on the error condition for
drm_of_find_panel_or_bridge, some reworking of the drm_panel_bridge_add
call, plus the data-lanes property parsing you were mentioning.

All those should be separate patches

Actually, I think I can drop this panel_bridge hunk too, which leaves 
only the lane count in this patch.






