drm/bridge: fsl-ldb: Add i.MX93 LDB support

Same to i.MX8mp LDB, i.MX93 LDB is controlled by mediamix blk-ctrl
through LDB_CTRL and LVDS_CTRL registers.  i.MX93 LDB supports only
one LVDS channel(channel 0) and it's LVDS_CTRL register bit1 is used
as LVDS_EN instead of CH1_EN.  Add i.MX93 LDB support in the existing
i.MX8mp LDB bridge driver by adding i.MX93 LDB compatible string and
device data(to reflect different register offsets and LVDS_CTRL register
bit1 definition).
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230123021449.969243-3-victor.liu@nxp.com

drivers/gpu/drm/bridge/fsl-ldb.c

@@ -18,7 +18,6 @@
 #include <drm/drm_of.h>
 #include <drm/drm_panel.h>
 
-#define LDB_CTRL				0x5c
 #define LDB_CTRL_CH0_ENABLE			BIT(0)
 #define LDB_CTRL_CH0_DI_SELECT			BIT(1)
 #define LDB_CTRL_CH1_ENABLE			BIT(2)
@@ -35,9 +34,13 @@
 #define LDB_CTRL_ASYNC_FIFO_ENABLE		BIT(24)
 #define LDB_CTRL_ASYNC_FIFO_THRESHOLD_MASK	GENMASK(27, 25)
 
-#define LVDS_CTRL				0x128
 #define LVDS_CTRL_CH0_EN			BIT(0)
 #define LVDS_CTRL_CH1_EN			BIT(1)
+/*
+ * LVDS_CTRL_LVDS_EN bit is poorly named in i.MX93 reference manual.
+ * Clear it to enable LVDS and set it to disable LVDS.
+ */
+#define LVDS_CTRL_LVDS_EN			BIT(1)
 #define LVDS_CTRL_VBG_EN			BIT(2)
 #define LVDS_CTRL_HS_EN				BIT(3)
 #define LVDS_CTRL_PRE_EMPH_EN			BIT(4)
@@ -52,6 +55,29 @@
 #define LVDS_CTRL_VBG_ADJ(n)			(((n) & 0x7) << 17)
 #define LVDS_CTRL_VBG_ADJ_MASK			GENMASK(19, 17)
 
+enum fsl_ldb_devtype {
+	IMX8MP_LDB,
+	IMX93_LDB,
+};
+
+struct fsl_ldb_devdata {
+	u32 ldb_ctrl;
+	u32 lvds_ctrl;
+	bool lvds_en_bit;
+};
+
+static const struct fsl_ldb_devdata fsl_ldb_devdata[] = {
+	[IMX8MP_LDB] = {
+		.ldb_ctrl = 0x5c,
+		.lvds_ctrl = 0x128,
+	},
+	[IMX93_LDB] = {
+		.ldb_ctrl = 0x20,
+		.lvds_ctrl = 0x24,
+		.lvds_en_bit = true,
+	},
+};
+
 struct fsl_ldb {
 	struct device *dev;
 	struct drm_bridge bridge;
@@ -59,6 +85,7 @@ struct fsl_ldb {
 	struct clk *clk;
 	struct regmap *regmap;
 	bool lvds_dual_link;
+	const struct fsl_ldb_devdata *devdata;
 };
 
 static inline struct fsl_ldb *to_fsl_ldb(struct drm_bridge *bridge)
@@ -173,12 +200,12 @@ static void fsl_ldb_atomic_enable(struct drm_bridge *bridge,
 			reg |= LDB_CTRL_DI1_VSYNC_POLARITY;
 	}
 
-	regmap_write(fsl_ldb->regmap, LDB_CTRL, reg);
+	regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->ldb_ctrl, reg);
 
 	/* 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, LVDS_CTRL, reg);
+	regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->lvds_ctrl, reg);
 
 	/* Wait for VBG to stabilize. */
 	usleep_range(15, 20);
@@ -187,7 +214,7 @@ static void fsl_ldb_atomic_enable(struct drm_bridge *bridge,
 	if (fsl_ldb->lvds_dual_link)
 		reg |= LVDS_CTRL_CH1_EN;
 
-	regmap_write(fsl_ldb->regmap, LVDS_CTRL, reg);
+	regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->lvds_ctrl, reg);
 }
 
 static void fsl_ldb_atomic_disable(struct drm_bridge *bridge,
@@ -195,9 +222,14 @@ static void fsl_ldb_atomic_disable(struct drm_bridge *bridge,
 {
 	struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge);
 
-	/* Stop both channels. */
-	regmap_write(fsl_ldb->regmap, LVDS_CTRL, 0);
-	regmap_write(fsl_ldb->regmap, LDB_CTRL, 0);
+	/* 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,
+			     LVDS_CTRL_LVDS_EN);
+	else
+		regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->lvds_ctrl, 0);
+	regmap_write(fsl_ldb->regmap, fsl_ldb->devdata->ldb_ctrl, 0);
 
 	clk_disable_unprepare(fsl_ldb->clk);
 }
@@ -263,6 +295,10 @@ static int fsl_ldb_probe(struct platform_device *pdev)
 	if (!fsl_ldb)
 		return -ENOMEM;
 
+	fsl_ldb->devdata = of_device_get_match_data(dev);
+	if (!fsl_ldb->devdata)
+		return -EINVAL;
+
 	fsl_ldb->dev = &pdev->dev;
 	fsl_ldb->bridge.funcs = &funcs;
 	fsl_ldb->bridge.of_node = dev->of_node;
@@ -321,7 +357,10 @@ static int fsl_ldb_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id fsl_ldb_match[] = {
-	{ .compatible = "fsl,imx8mp-ldb", },
+	{ .compatible = "fsl,imx8mp-ldb",
+	  .data = &fsl_ldb_devdata[IMX8MP_LDB], },
+	{ .compatible = "fsl,imx93-ldb",
+	  .data = &fsl_ldb_devdata[IMX93_LDB], },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, fsl_ldb_match);