drm/gma500: Make oaktrail lvds use ddc adapter from drm_connector

We're moving all uses of ddc_bus to drm_connector where they belong.
The initialization of the gma_i2c_chan for Oaktrail is a bit backwards
so it required improvements. Also cleanup the error handling in
oaktrail_lvds_init(). Since this is the last user of
gma_encoder->ddc_bus we can remove it.
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220601092311.22648-8-patrik.r.jakobsson@gmail.com

drivers/gpu/drm/gma500/oaktrail_lvds.c

@@ -293,12 +293,14 @@ void oaktrail_lvds_init(struct drm_device *dev,
 {
 	struct gma_encoder *gma_encoder;
 	struct gma_connector *gma_connector;
+	struct gma_i2c_chan *ddc_bus;
 	struct drm_connector *connector;
 	struct drm_encoder *encoder;
 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 	struct edid *edid;
 	struct i2c_adapter *i2c_adap;
 	struct drm_display_mode *scan;	/* *modes, *bios_mode; */
+	int ret;
 
 	gma_encoder = kzalloc(sizeof(struct gma_encoder), GFP_KERNEL);
 	if (!gma_encoder)
@@ -306,16 +308,20 @@ void oaktrail_lvds_init(struct drm_device *dev,
 
 	gma_connector = kzalloc(sizeof(struct gma_connector), GFP_KERNEL);
 	if (!gma_connector)
-		goto failed_connector;
+		goto err_free_encoder;
 
 	connector = &gma_connector->base;
 	encoder = &gma_encoder->base;
 	dev_priv->is_lvds_on = true;
-	drm_connector_init(dev, connector,
-			   &psb_intel_lvds_connector_funcs,
-			   DRM_MODE_CONNECTOR_LVDS);
+	ret = drm_connector_init(dev, connector,
+				 &psb_intel_lvds_connector_funcs,
+				 DRM_MODE_CONNECTOR_LVDS);
+	if (ret)
+		goto err_free_connector;
 
-	drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_LVDS);
+	ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_LVDS);
+	if (ret)
+		goto err_connector_cleanup;
 
 	gma_connector_attach_encoder(gma_connector, gma_encoder);
 	gma_encoder->type = INTEL_OUTPUT_LVDS;
@@ -353,16 +359,26 @@ void oaktrail_lvds_init(struct drm_device *dev,
 
 	edid = NULL;
 	mutex_lock(&dev->mode_config.mutex);
+
 	i2c_adap = i2c_get_adapter(dev_priv->ops->i2c_bus);
 	if (i2c_adap)
 		edid = drm_get_edid(connector, i2c_adap);
+
 	if (edid == NULL && dev_priv->lpc_gpio_base) {
-		oaktrail_lvds_i2c_init(encoder);
-		if (gma_encoder->ddc_bus != NULL) {
-			i2c_adap = &gma_encoder->ddc_bus->base;
+		ddc_bus = oaktrail_lvds_i2c_init(dev);
+		if (!IS_ERR(ddc_bus)) {
+			i2c_adap = &ddc_bus->base;
 			edid = drm_get_edid(connector, i2c_adap);
 		}
 	}
+
+	/*
+	 * Due to the logic in probing for i2c buses above we do not know the
+	 * i2c_adap until now. Hence we cannot use drm_connector_init_with_ddc()
+	 * but must instead set connector->ddc manually here.
+	 */
+	connector->ddc = i2c_adap;
+
 	/*
 	 * Attempt to get the fixed panel mode from DDC.  Assume that the
 	 * preferred mode is the right one.
@@ -395,7 +411,7 @@ void oaktrail_lvds_init(struct drm_device *dev,
 	/* If we still don't have a mode after all that, give up. */
 	if (!mode_dev->panel_fixed_mode) {
 		dev_err(dev->dev, "Found no modes on the lvds, ignoring the LVDS\n");
-		goto failed_find;
+		goto err_unlock;
 	}
 
 out:
@@ -403,21 +419,15 @@ void oaktrail_lvds_init(struct drm_device *dev,
 
 	return;
 
-failed_find:
+err_unlock:
 	mutex_unlock(&dev->mode_config.mutex);
-
-	dev_dbg(dev->dev, "No LVDS modes found, disabling.\n");
-	if (gma_encoder->ddc_bus) {
-		gma_i2c_destroy(gma_encoder->ddc_bus);
-		gma_encoder->ddc_bus = NULL;
-	}
-
-/* failed_ddc: */
-
+	gma_i2c_destroy(to_gma_i2c_chan(connector->ddc));
 	drm_encoder_cleanup(encoder);
+err_connector_cleanup:
 	drm_connector_cleanup(connector);
+err_free_connector:
 	kfree(gma_connector);
-failed_connector:
+err_free_encoder:
 	kfree(gma_encoder);
 }
 

drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c

@@ -129,16 +129,15 @@ static void set_data(void *data, int state_high)
 	}
 }
 
-void oaktrail_lvds_i2c_init(struct drm_encoder *encoder)
+struct gma_i2c_chan *oaktrail_lvds_i2c_init(struct drm_device *dev)
 {
-	struct drm_device *dev = encoder->dev;
-	struct gma_encoder *gma_encoder = to_gma_encoder(encoder);
 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 	struct gma_i2c_chan *chan;
+	int ret;
 
 	chan = kzalloc(sizeof(struct gma_i2c_chan), GFP_KERNEL);
 	if (!chan)
-		return;
+		return ERR_PTR(-ENOMEM);
 
 	chan->drm_dev = dev;
 	chan->reg = dev_priv->lpc_gpio_base;
@@ -160,10 +159,11 @@ void oaktrail_lvds_i2c_init(struct drm_encoder *encoder)
 	set_clock(chan, 1);
 	udelay(50);
 
-	if (i2c_bit_add_bus(&chan->base)) {
+	ret = i2c_bit_add_bus(&chan->base);
+	if (ret < 0) {
 		kfree(chan);
-		return;
+		return ERR_PTR(ret);
 	}
 
-	gma_encoder->ddc_bus = chan;
+	return chan;
 }

drivers/gpu/drm/gma500/psb_intel_drv.h

@@ -105,7 +105,6 @@ struct gma_encoder {
 	/* FIXME: Either make SDVO and LVDS store it's i2c here or give CDV it's
 	   own set of output privates */
 	struct gma_i2c_chan *i2c_bus;
-	struct gma_i2c_chan *ddc_bus;
 };
 
 struct gma_connector {
@@ -200,7 +199,7 @@ extern void oaktrail_lvds_init(struct drm_device *dev,
 extern void oaktrail_wait_for_INTR_PKT_SENT(struct drm_device *dev);
 extern void oaktrail_dsi_init(struct drm_device *dev,
 			   struct psb_intel_mode_device *mode_dev);
-extern void oaktrail_lvds_i2c_init(struct drm_encoder *encoder);
+struct gma_i2c_chan *oaktrail_lvds_i2c_init(struct drm_device *dev);
 extern void mid_dsi_init(struct drm_device *dev,
 		    struct psb_intel_mode_device *mode_dev, int dsi_num);