drm: bridge: icn6211: Add DSI lane count DT property parsing

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@denx.de>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
To: dri-devel@lists.freedesktop.org
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407185617.179573-2-marex@denx.de

diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c
index 6ce0633d4c08947417e692f07302d29b4565e77b..47dea657a752bb5e1bc5ea621c26ef5881ecaa49 100644 (file)
--- a/drivers/gpu/drm/bridge/chipone-icn6211.c
+++ b/drivers/gpu/drm/bridge/chipone-icn6211.c
@@ -395,6 +395,11 @@ static void chipone_atomic_enable(struct drm_bridge *bridge,
        /* dsi specific sequence */
        chipone_writeb(icn, SYNC_EVENT_DLY, 0x80);
        chipone_writeb(icn, HFP_MIN, hfp & 0xff);
+
+       /* DSI data lane count */
+       chipone_writeb(icn, DSI_CTRL,
+                      DSI_CTRL_UNKNOWN | DSI_CTRL_DSI_LANES(icn->dsi->lanes - 1));
+
        chipone_writeb(icn, MIPI_PD_CK_LANE, 0xa0);
        chipone_writeb(icn, PLL_CTRL(12), 0xff);
        chipone_writeb(icn, MIPI_PN_SWAP, 0x00);
@@ -480,9 +485,23 @@ static void chipone_mode_set(struct drm_bridge *bridge,
 static int chipone_dsi_attach(struct chipone *icn)
 {
        struct mipi_dsi_device *dsi = icn->dsi;
-       int ret;
+       struct device *dev = icn->dev;
+       struct device_node *endpoint;
+       int dsi_lanes, ret;
+
+       endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
+       dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
+       of_node_put(endpoint);
+
+       /*
+        * If the 'data-lanes' property does not exist in DT or is invalid,
+        * default to previously hard-coded behavior, which was 4 data lanes.
+        */
+       if (dsi_lanes >= 1 && dsi_lanes <= 4)
+               icn->dsi->lanes = dsi_lanes;
+       else
+               icn->dsi->lanes = 4;
 
-       dsi->lanes = 4;
        dsi->format = MIPI_DSI_FMT_RGB888;
        dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
                          MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET;