[PATCH v3] drm/bridge: fsl-ldb: Parse register offsets from DT

[Marek Vasut <marek.vasut@mailbox.org>]

The DT bindings for this bridge describe register offsets for the LDB,
parse the register offsets from DT instead of hard-coding them in the
driver. No functional change.

The LDB was always meant to parse the 'reg' offsets out of the DT, it
only went somewhat wrong in the process and we ended up with hard-coded
reg<->compatible mapping. It was never intended to be that way, so fix
it.

Signed-off-by: Marek Vasut <marek.vasut@mailbox.org>
---
Cc: Abel Vesa <abelvesa@kernel.org>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Liu Ying <victor.liu@nxp.com>
Cc: Luca Ceresoli <luca.ceresoli@bootlin.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: devicetree@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: imx@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-clk@vger.kernel.org
---
V2: - Switch to of_property_read_reg()
    - Parse single-register LDB variants from DT too
V3: - Update commit message
    - Drop "likely" from the comment
---
 drivers/gpu/drm/bridge/fsl-ldb.c | 58 ++++++++++++++++++++------------
 1 file changed, 36 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/bridge/fsl-ldb.c b/drivers/gpu/drm/bridge/fsl-ldb.c
index 5c3cf37200bce..aa352c70b9ab2 100644
--- a/drivers/gpu/drm/bridge/fsl-ldb.c
+++ b/drivers/gpu/drm/bridge/fsl-ldb.c
@@ -8,6 +8,7 @@
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/of_graph.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
@@ -61,24 +62,13 @@ enum fsl_ldb_devtype {
 };
 
 struct fsl_ldb_devdata {
-	u32 ldb_ctrl;
-	u32 lvds_ctrl;
 	bool lvds_en_bit;
-	bool single_ctrl_reg;
 };
 
 static const struct fsl_ldb_devdata fsl_ldb_devdata[] = {
-	[IMX6SX_LDB] = {
-		.ldb_ctrl = 0x18,
-		.single_ctrl_reg = true,
-	},
-	[IMX8MP_LDB] = {
-		.ldb_ctrl = 0x5c,
-		.lvds_ctrl = 0x128,
-	},
+	[IMX6SX_LDB] = { },
+	[IMX8MP_LDB] = { },
 	[IMX93_LDB] = {
-		.ldb_ctrl = 0x20,
-		.lvds_ctrl = 0x24,
 		.lvds_en_bit = true,
 	},
 };
@@ -90,8 +80,11 @@ struct fsl_ldb {
 	struct clk *clk;
 	struct regmap *regmap;
 	const struct fsl_ldb_devdata *devdata;
+	u64 ldb_ctrl;
+	u64 lvds_ctrl;
 	bool ch0_enabled;
 	bool ch1_enabled;
+	bool single_ctrl_reg;
 };
 
 static bool fsl_ldb_is_dual(const struct fsl_ldb *fsl_ldb)
@@ -204,15 +197,15 @@ static void fsl_ldb_atomic_enable(struct drm_bridge *bridge,
 		reg |=	(fsl_ldb->ch0_enabled ? LDB_CTRL_DI0_VSYNC_POLARITY : 0) |
 			(fsl_ldb->ch1_enabled ? LDB_CTRL_DI1_VSYNC_POLARITY : 0);
 
-	regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->ldb_ctrl, reg);
+	regmap_write(fsl_ldb->regmap, fsl_ldb->ldb_ctrl, reg);
 
-	if (fsl_ldb->devdata->single_ctrl_reg)
+	if (fsl_ldb->single_ctrl_reg)
 		return;
 
 	/* Program LVDS_CTRL */
 	reg = LVDS_CTRL_CC_ADJ(2) | LVDS_CTRL_PRE_EMPH_EN |
 	      LVDS_CTRL_PRE_EMPH_ADJ(3) | LVDS_CTRL_VBG_EN;
-	regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->lvds_ctrl, reg);
+	regmap_write(fsl_ldb->regmap, fsl_ldb->lvds_ctrl, reg);
 
 	/* Wait for VBG to stabilize. */
 	usleep_range(15, 20);
@@ -220,7 +213,7 @@ static void fsl_ldb_atomic_enable(struct drm_bridge *bridge,
 	reg |=	(fsl_ldb->ch0_enabled ? LVDS_CTRL_CH0_EN : 0) |
 		(fsl_ldb->ch1_enabled ? LVDS_CTRL_CH1_EN : 0);
 
-	regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->lvds_ctrl, reg);
+	regmap_write(fsl_ldb->regmap, fsl_ldb->lvds_ctrl, reg);
 }
 
 static void fsl_ldb_atomic_disable(struct drm_bridge *bridge,
@@ -231,12 +224,12 @@ static void fsl_ldb_atomic_disable(struct drm_bridge *bridge,
 	/* Stop channel(s). */
 	if (fsl_ldb->devdata->lvds_en_bit)
 		/* Set LVDS_CTRL_LVDS_EN bit to disable. */
-		regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->lvds_ctrl,
+		regmap_write(fsl_ldb->regmap, fsl_ldb->lvds_ctrl,
 			     LVDS_CTRL_LVDS_EN);
 	else
-		if (!fsl_ldb->devdata->single_ctrl_reg)
-			regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->lvds_ctrl, 0);
-	regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->ldb_ctrl, 0);
+		if (!fsl_ldb->single_ctrl_reg)
+			regmap_write(fsl_ldb->regmap, fsl_ldb->lvds_ctrl, 0);
+	regmap_write(fsl_ldb->regmap, fsl_ldb->ldb_ctrl, 0);
 
 	clk_disable_unprepare(fsl_ldb->clk);
 }
@@ -296,7 +289,7 @@ static int fsl_ldb_probe(struct platform_device *pdev)
 	struct device_node *remote1, *remote2;
 	struct drm_panel *panel;
 	struct fsl_ldb *fsl_ldb;
-	int dual_link;
+	int dual_link, idx, ret;
 
 	fsl_ldb = devm_drm_bridge_alloc(dev, struct fsl_ldb, bridge, &funcs);
 	if (IS_ERR(fsl_ldb))
@@ -309,6 +302,27 @@ static int fsl_ldb_probe(struct platform_device *pdev)
 	fsl_ldb->dev = &pdev->dev;
 	fsl_ldb->bridge.of_node = dev->of_node;
 
+	/* No "reg-names" property means single-register LDB */
+	idx = of_property_match_string(dev->of_node, "reg-names", "ldb");
+	if (idx < 0) {
+		fsl_ldb->single_ctrl_reg = true;
+		idx = 0;
+	}
+
+	ret = of_property_read_reg(dev->of_node, idx, &fsl_ldb->ldb_ctrl, NULL);
+	if (ret)
+		return ret;
+
+	if (!fsl_ldb->single_ctrl_reg) {
+		idx = of_property_match_string(dev->of_node, "reg-names", "lvds");
+		if (idx < 0)
+			return idx;
+
+		ret = of_property_read_reg(dev->of_node, idx, &fsl_ldb->lvds_ctrl, NULL);
+		if (ret)
+			return ret;
+	}
+
 	fsl_ldb->clk = devm_clk_get(dev, "ldb");
 	if (IS_ERR(fsl_ldb->clk))
 		return PTR_ERR(fsl_ldb->clk);
-- 
2.51.0