drm/bridge: ti-sn65dsi86: fetch bpc using drm_atomic_state

Rather than reading the pdata->connector directly, fetch the connector
using drm_atomic_state. This allows us to make pdata->connector optional
(and thus supporting DRM_BRIDGE_ATTACH_NO_CONNECTOR).
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Steev Klimaszewski <steev@kali.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220711092117.360797-2-dmitry.baryshkov@linaro.org

drivers/gpu/drm/bridge/ti-sn65dsi86.c

@@ -779,9 +779,9 @@ static void ti_sn_bridge_set_dsi_rate(struct ti_sn65dsi86 *pdata)
 	regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
 }
 
-static unsigned int ti_sn_bridge_get_bpp(struct ti_sn65dsi86 *pdata)
+static unsigned int ti_sn_bridge_get_bpp(struct drm_connector *connector)
 {
-	if (pdata->connector->display_info.bpc <= 6)
+	if (connector->display_info.bpc <= 6)
 		return 18;
 	else
 		return 24;
@@ -796,7 +796,7 @@ static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
 	0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
 };
 
-static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata)
+static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata, unsigned int bpp)
 {
 	unsigned int bit_rate_khz, dp_rate_mhz;
 	unsigned int i;
@@ -804,7 +804,7 @@ static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata)
 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
 
 	/* Calculate minimum bit rate based on our pixel clock. */
-	bit_rate_khz = mode->clock * ti_sn_bridge_get_bpp(pdata);
+	bit_rate_khz = mode->clock * bpp;
 
 	/* Calculate minimum DP data rate, taking 80% as per DP spec */
 	dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM,
@@ -1016,12 +1016,21 @@ static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
 				       struct drm_bridge_state *old_bridge_state)
 {
 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
+	struct drm_connector *connector;
 	const char *last_err_str = "No supported DP rate";
 	unsigned int valid_rates;
 	int dp_rate_idx;
 	unsigned int val;
 	int ret = -EINVAL;
 	int max_dp_lanes;
+	unsigned int bpp;
+
+	connector = drm_atomic_get_new_connector_for_encoder(old_bridge_state->base.state,
+							     bridge->encoder);
+	if (!connector) {
+		dev_err_ratelimited(pdata->dev, "Could not get the connector\n");
+		return;
+	}
 
 	max_dp_lanes = ti_sn_get_max_lanes(pdata);
 	pdata->dp_lanes = min(pdata->dp_lanes, max_dp_lanes);
@@ -1047,8 +1056,9 @@ static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
 	drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
 			   DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
 
+	bpp = ti_sn_bridge_get_bpp(connector);
 	/* Set the DP output format (18 bpp or 24 bpp) */
-	val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
+	val = bpp == 18 ? BPP_18_RGB : 0;
 	regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
 
 	/* DP lane config */
@@ -1059,7 +1069,7 @@ static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
 	valid_rates = ti_sn_bridge_read_valid_rates(pdata);
 
 	/* Train until we run out of rates */
-	for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata);
+	for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata, bpp);
 	     dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
 	     dp_rate_idx++) {
 		if (!(valid_rates & BIT(dp_rate_idx)))