drm/bridge: imx8*-ldb: convert to devm_drm_bridge_alloc() API

This is the new API for allocating DRM bridges.

These two drivers are tangled together by the ldb_add_bridge_helper(), so
they are converted at once.

They also have a similar design, each embedding an array of channels in
their main struct, and each channel embeds a drm_bridge. This prevents
dynamic, refcount-based deallocation of the bridges.

To make the new, dynamic bridge allocation possible:

 * change the array of channels into an array of channel pointers
 * allocate each channel using devm_drm_bridge_alloc()
 * adapt ldb_add_bridge_helper() to not set the funcs pointer
   (now done by devm_drm_bridge_alloc())
 * adapt the code wherever using the channels

Signed-off-by: Luca Ceresoli <[email protected]>
Acked-by: Liu Ying <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20250424-drm-bridge-convert-to-alloc-api-v2-31-8f91a404d86b@bootlin.com
Signed-off-by: Louis Chauvet <[email protected]>

Author: lucaceresoli

drivers/gpu/drm/bridge/imx/imx-ldb-helper.c

@@ -190,8 +190,7 @@ int ldb_find_next_bridge_helper(struct ldb *ldb)
 }
 EXPORT_SYMBOL_GPL(ldb_find_next_bridge_helper);
 
-void ldb_add_bridge_helper(struct ldb *ldb,
-			   const struct drm_bridge_funcs *bridge_funcs)
+void ldb_add_bridge_helper(struct ldb *ldb)
 {
 	struct ldb_channel *ldb_ch;
 	int i;
@@ -203,7 +202,6 @@ void ldb_add_bridge_helper(struct ldb *ldb,
 			continue;
 
 		ldb_ch->bridge.driver_private = ldb_ch;
-		ldb_ch->bridge.funcs = bridge_funcs;
 		ldb_ch->bridge.of_node = ldb_ch->np;
 
 		drm_bridge_add(&ldb_ch->bridge);

drivers/gpu/drm/bridge/imx/imx-ldb-helper.h

@@ -88,8 +88,7 @@ int ldb_init_helper(struct ldb *ldb);
 
 int ldb_find_next_bridge_helper(struct ldb *ldb);
 
-void ldb_add_bridge_helper(struct ldb *ldb,
-			   const struct drm_bridge_funcs *bridge_funcs);
+void ldb_add_bridge_helper(struct ldb *ldb);
 
 void ldb_remove_bridge_helper(struct ldb *ldb);
 

drivers/gpu/drm/bridge/imx/imx8qm-ldb.c

@@ -47,7 +47,7 @@ struct imx8qm_ldb_channel {
 struct imx8qm_ldb {
 	struct ldb base;
 	struct device *dev;
-	struct imx8qm_ldb_channel channel[MAX_LDB_CHAN_NUM];
+	struct imx8qm_ldb_channel *channel[MAX_LDB_CHAN_NUM];
 	struct clk *clk_pixel;
 	struct clk *clk_bypass;
 	int active_chno;
@@ -107,7 +107,7 @@ static int imx8qm_ldb_bridge_atomic_check(struct drm_bridge *bridge,
 
 	if (is_split) {
 		imx8qm_ldb_ch =
-			&imx8qm_ldb->channel[imx8qm_ldb->active_chno ^ 1];
+			imx8qm_ldb->channel[imx8qm_ldb->active_chno ^ 1];
 		imx8qm_ldb_set_phy_cfg(imx8qm_ldb, di_clk, is_split, true,
 				       phy_cfg);
 		ret = phy_validate(imx8qm_ldb_ch->phy, PHY_MODE_LVDS, 0, &opts);
@@ -158,7 +158,7 @@ imx8qm_ldb_bridge_mode_set(struct drm_bridge *bridge,
 
 	if (is_split) {
 		imx8qm_ldb_ch =
-			&imx8qm_ldb->channel[imx8qm_ldb->active_chno ^ 1];
+			imx8qm_ldb->channel[imx8qm_ldb->active_chno ^ 1];
 		imx8qm_ldb_set_phy_cfg(imx8qm_ldb, di_clk, is_split, true,
 				       phy_cfg);
 		ret = phy_configure(imx8qm_ldb_ch->phy, &opts);
@@ -226,13 +226,13 @@ static void imx8qm_ldb_bridge_atomic_enable(struct drm_bridge *bridge,
 	}
 
 	if (is_split) {
-		ret = phy_power_on(imx8qm_ldb->channel[0].phy);
+		ret = phy_power_on(imx8qm_ldb->channel[0]->phy);
 		if (ret)
 			DRM_DEV_ERROR(dev,
 				      "failed to power on channel0 PHY: %d\n",
 				      ret);
 
-		ret = phy_power_on(imx8qm_ldb->channel[1].phy);
+		ret = phy_power_on(imx8qm_ldb->channel[1]->phy);
 		if (ret)
 			DRM_DEV_ERROR(dev,
 				      "failed to power on channel1 PHY: %d\n",
@@ -261,12 +261,12 @@ static void imx8qm_ldb_bridge_atomic_disable(struct drm_bridge *bridge,
 	ldb_bridge_disable_helper(bridge);
 
 	if (is_split) {
-		ret = phy_power_off(imx8qm_ldb->channel[0].phy);
+		ret = phy_power_off(imx8qm_ldb->channel[0]->phy);
 		if (ret)
 			DRM_DEV_ERROR(dev,
 				      "failed to power off channel0 PHY: %d\n",
 				      ret);
-		ret = phy_power_off(imx8qm_ldb->channel[1].phy);
+		ret = phy_power_off(imx8qm_ldb->channel[1]->phy);
 		if (ret)
 			DRM_DEV_ERROR(dev,
 				      "failed to power off channel1 PHY: %d\n",
@@ -412,7 +412,7 @@ static int imx8qm_ldb_get_phy(struct imx8qm_ldb *imx8qm_ldb)
 	int i, ret;
 
 	for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
-		imx8qm_ldb_ch = &imx8qm_ldb->channel[i];
+		imx8qm_ldb_ch = imx8qm_ldb->channel[i];
 		ldb_ch = &imx8qm_ldb_ch->base;
 
 		if (!ldb_ch->is_available)
@@ -448,6 +448,14 @@ static int imx8qm_ldb_probe(struct platform_device *pdev)
 	if (!imx8qm_ldb)
 		return -ENOMEM;
 
+	for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
+		imx8qm_ldb->channel[i] =
+			devm_drm_bridge_alloc(dev, struct imx8qm_ldb_channel, base.bridge,
+					      &imx8qm_ldb_bridge_funcs);
+		if (IS_ERR(imx8qm_ldb->channel[i]))
+			return PTR_ERR(imx8qm_ldb->channel[i]);
+	}
+
 	imx8qm_ldb->clk_pixel = devm_clk_get(dev, "pixel");
 	if (IS_ERR(imx8qm_ldb->clk_pixel)) {
 		ret = PTR_ERR(imx8qm_ldb->clk_pixel);
@@ -473,7 +481,7 @@ static int imx8qm_ldb_probe(struct platform_device *pdev)
 	ldb->ctrl_reg = 0xe0;
 
 	for (i = 0; i < MAX_LDB_CHAN_NUM; i++)
-		ldb->channel[i] = &imx8qm_ldb->channel[i].base;
+		ldb->channel[i] = &imx8qm_ldb->channel[i]->base;
 
 	ret = ldb_init_helper(ldb);
 	if (ret)
@@ -499,12 +507,12 @@ static int imx8qm_ldb_probe(struct platform_device *pdev)
 		}
 
 		imx8qm_ldb->active_chno = 0;
-		imx8qm_ldb_ch = &imx8qm_ldb->channel[0];
+		imx8qm_ldb_ch = imx8qm_ldb->channel[0];
 		ldb_ch = &imx8qm_ldb_ch->base;
 		ldb_ch->link_type = pixel_order;
 	} else {
 		for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
-			imx8qm_ldb_ch = &imx8qm_ldb->channel[i];
+			imx8qm_ldb_ch = imx8qm_ldb->channel[i];
 			ldb_ch = &imx8qm_ldb_ch->base;
 
 			if (ldb_ch->is_available) {
@@ -525,7 +533,7 @@ static int imx8qm_ldb_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, imx8qm_ldb);
 	pm_runtime_enable(dev);
 
-	ldb_add_bridge_helper(ldb, &imx8qm_ldb_bridge_funcs);
+	ldb_add_bridge_helper(ldb);
 
 	return ret;
 }

drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c

@@ -44,7 +44,7 @@ struct imx8qxp_ldb_channel {
 struct imx8qxp_ldb {
 	struct ldb base;
 	struct device *dev;
-	struct imx8qxp_ldb_channel channel[MAX_LDB_CHAN_NUM];
+	struct imx8qxp_ldb_channel *channel[MAX_LDB_CHAN_NUM];
 	struct clk *clk_pixel;
 	struct clk *clk_bypass;
 	struct drm_bridge *companion;
@@ -410,7 +410,7 @@ static const struct drm_bridge_funcs imx8qxp_ldb_bridge_funcs = {
 static int imx8qxp_ldb_set_di_id(struct imx8qxp_ldb *imx8qxp_ldb)
 {
 	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
-			 &imx8qxp_ldb->channel[imx8qxp_ldb->active_chno];
+			 imx8qxp_ldb->channel[imx8qxp_ldb->active_chno];
 	struct ldb_channel *ldb_ch = &imx8qxp_ldb_ch->base;
 	struct device_node *ep, *remote;
 	struct device *dev = imx8qxp_ldb->dev;
@@ -456,7 +456,7 @@ imx8qxp_ldb_check_chno_and_dual_link(struct ldb_channel *ldb_ch, int link)
 static int imx8qxp_ldb_parse_dt_companion(struct imx8qxp_ldb *imx8qxp_ldb)
 {
 	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
-			 &imx8qxp_ldb->channel[imx8qxp_ldb->active_chno];
+			 imx8qxp_ldb->channel[imx8qxp_ldb->active_chno];
 	struct ldb_channel *ldb_ch = &imx8qxp_ldb_ch->base;
 	struct ldb_channel *companion_ldb_ch;
 	struct device_node *companion;
@@ -586,6 +586,14 @@ static int imx8qxp_ldb_probe(struct platform_device *pdev)
 	if (!imx8qxp_ldb)
 		return -ENOMEM;
 
+	for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
+		imx8qxp_ldb->channel[i] =
+			devm_drm_bridge_alloc(dev, struct imx8qxp_ldb_channel, base.bridge,
+					      &imx8qxp_ldb_bridge_funcs);
+		if (IS_ERR(imx8qxp_ldb->channel[i]))
+			return PTR_ERR(imx8qxp_ldb->channel[i]);
+	}
+
 	imx8qxp_ldb->clk_pixel = devm_clk_get(dev, "pixel");
 	if (IS_ERR(imx8qxp_ldb->clk_pixel)) {
 		ret = PTR_ERR(imx8qxp_ldb->clk_pixel);
@@ -611,7 +619,7 @@ static int imx8qxp_ldb_probe(struct platform_device *pdev)
 	ldb->ctrl_reg = 0xe0;
 
 	for (i = 0; i < MAX_LDB_CHAN_NUM; i++)
-		ldb->channel[i] = &imx8qxp_ldb->channel[i].base;
+		ldb->channel[i] = &imx8qxp_ldb->channel[i]->base;
 
 	ret = ldb_init_helper(ldb);
 	if (ret)
@@ -627,7 +635,7 @@ static int imx8qxp_ldb_probe(struct platform_device *pdev)
 	}
 
 	for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
-		imx8qxp_ldb_ch = &imx8qxp_ldb->channel[i];
+		imx8qxp_ldb_ch = imx8qxp_ldb->channel[i];
 		ldb_ch = &imx8qxp_ldb_ch->base;
 
 		if (ldb_ch->is_available) {
@@ -660,7 +668,7 @@ static int imx8qxp_ldb_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, imx8qxp_ldb);
 	pm_runtime_enable(dev);
 
-	ldb_add_bridge_helper(ldb, &imx8qxp_ldb_bridge_funcs);
+	ldb_add_bridge_helper(ldb);
 
 	return 0;
 }