1 files changed, 406 insertions, 0 deletions
diff --git a/drivers/gpu/drm/bridge/fsl-ldb.c b/drivers/gpu/drm/bridge/fsl-ldb.c
new file mode 100644
index 000000000..0e4bac7dd
--- /dev/null
+++ b/drivers/gpu/drm/bridge/fsl-ldb.c
@@ -0,0 +1,406 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2022 Marek Vasut <marex@denx.de>
+ */
+
+#include <linux/clk.h>
+#include <linux/media-bus-format.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+
+#define LDB_CTRL_CH0_ENABLE			BIT(0)
+#define LDB_CTRL_CH0_DI_SELECT			BIT(1)
+#define LDB_CTRL_CH1_ENABLE			BIT(2)
+#define LDB_CTRL_CH1_DI_SELECT			BIT(3)
+#define LDB_CTRL_SPLIT_MODE			BIT(4)
+#define LDB_CTRL_CH0_DATA_WIDTH			BIT(5)
+#define LDB_CTRL_CH0_BIT_MAPPING		BIT(6)
+#define LDB_CTRL_CH1_DATA_WIDTH			BIT(7)
+#define LDB_CTRL_CH1_BIT_MAPPING		BIT(8)
+#define LDB_CTRL_DI0_VSYNC_POLARITY		BIT(9)
+#define LDB_CTRL_DI1_VSYNC_POLARITY		BIT(10)
+#define LDB_CTRL_REG_CH0_FIFO_RESET		BIT(11)
+#define LDB_CTRL_REG_CH1_FIFO_RESET		BIT(12)
+#define LDB_CTRL_ASYNC_FIFO_ENABLE		BIT(24)
+#define LDB_CTRL_ASYNC_FIFO_THRESHOLD_MASK	GENMASK(27, 25)
+
+#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)
+#define LVDS_CTRL_PRE_EMPH_ADJ(n)		(((n) & 0x7) << 5)
+#define LVDS_CTRL_PRE_EMPH_ADJ_MASK		GENMASK(7, 5)
+#define LVDS_CTRL_CM_ADJ(n)			(((n) & 0x7) << 8)
+#define LVDS_CTRL_CM_ADJ_MASK			GENMASK(10, 8)
+#define LVDS_CTRL_CC_ADJ(n)			(((n) & 0x7) << 11)
+#define LVDS_CTRL_CC_ADJ_MASK			GENMASK(13, 11)
+#define LVDS_CTRL_SLEW_ADJ(n)			(((n) & 0x7) << 14)
+#define LVDS_CTRL_SLEW_ADJ_MASK			GENMASK(16, 14)
+#define LVDS_CTRL_VBG_ADJ(n)			(((n) & 0x7) << 17)
+#define LVDS_CTRL_VBG_ADJ_MASK			GENMASK(19, 17)
+
+enum fsl_ldb_devtype {
+	IMX6SX_LDB,
+	IMX8MP_LDB,
+	IMX93_LDB,
+};
+
+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,
+	},
+	[IMX93_LDB] = {
+		.ldb_ctrl = 0x20,
+		.lvds_ctrl = 0x24,
+		.lvds_en_bit = true,
+	},
+};
+
+struct fsl_ldb {
+	struct device *dev;
+	struct drm_bridge bridge;
+	struct drm_bridge *panel_bridge;
+	struct clk *clk;
+	struct regmap *regmap;
+	const struct fsl_ldb_devdata *devdata;
+	bool ch0_enabled;
+	bool ch1_enabled;
+};
+
+static bool fsl_ldb_is_dual(const struct fsl_ldb *fsl_ldb)
+{
+	return (fsl_ldb->ch0_enabled && fsl_ldb->ch1_enabled);
+}
+
+static inline struct fsl_ldb *to_fsl_ldb(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct fsl_ldb, bridge);
+}
+
+static unsigned long fsl_ldb_link_frequency(struct fsl_ldb *fsl_ldb, int clock)
+{
+	if (fsl_ldb_is_dual(fsl_ldb))
+		return clock * 3500;
+	else
+		return clock * 7000;
+}
+
+static int fsl_ldb_attach(struct drm_bridge *bridge,
+			  enum drm_bridge_attach_flags flags)
+{
+	struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge);
+
+	return drm_bridge_attach(bridge->encoder, fsl_ldb->panel_bridge,
+				 bridge, flags);
+}
+
+static void fsl_ldb_atomic_enable(struct drm_bridge *bridge,
+				  struct drm_bridge_state *old_bridge_state)
+{
+	struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge);
+	struct drm_atomic_state *state = old_bridge_state->base.state;
+	const struct drm_bridge_state *bridge_state;
+	const struct drm_crtc_state *crtc_state;
+	const struct drm_display_mode *mode;
+	struct drm_connector *connector;
+	struct drm_crtc *crtc;
+	unsigned long configured_link_freq;
+	unsigned long requested_link_freq;
+	bool lvds_format_24bpp;
+	bool lvds_format_jeida;
+	u32 reg;
+
+	/* Get the LVDS format from the bridge state. */
+	bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
+
+	switch (bridge_state->output_bus_cfg.format) {
+	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
+		lvds_format_24bpp = false;
+		lvds_format_jeida = true;
+		break;
+	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
+		lvds_format_24bpp = true;
+		lvds_format_jeida = true;
+		break;
+	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
+		lvds_format_24bpp = true;
+		lvds_format_jeida = false;
+		break;
+	default:
+		/*
+		 * Some bridges still don't set the correct LVDS bus pixel
+		 * format, use SPWG24 default format until those are fixed.
+		 */
+		lvds_format_24bpp = true;
+		lvds_format_jeida = false;
+		dev_warn(fsl_ldb->dev,
+			 "Unsupported LVDS bus format 0x%04x, please check output bridge driver. Falling back to SPWG24.\n",
+			 bridge_state->output_bus_cfg.format);
+		break;
+	}
+
+	/*
+	 * Retrieve the CRTC adjusted mode. This requires a little dance to go
+	 * from the bridge to the encoder, to the connector and to the CRTC.
+	 */
+	connector = drm_atomic_get_new_connector_for_encoder(state,
+							     bridge->encoder);
+	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
+	crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+	mode = &crtc_state->adjusted_mode;
+
+	requested_link_freq = fsl_ldb_link_frequency(fsl_ldb, mode->clock);
+	clk_set_rate(fsl_ldb->clk, requested_link_freq);
+
+	configured_link_freq = clk_get_rate(fsl_ldb->clk);
+	if (configured_link_freq != requested_link_freq)
+		dev_warn(fsl_ldb->dev, "Configured LDB clock (%lu Hz) does not match requested LVDS clock: %lu Hz\n",
+			 configured_link_freq,
+			 requested_link_freq);
+
+	clk_prepare_enable(fsl_ldb->clk);
+
+	/* Program LDB_CTRL */
+	reg =	(fsl_ldb->ch0_enabled ? LDB_CTRL_CH0_ENABLE : 0) |
+		(fsl_ldb->ch1_enabled ? LDB_CTRL_CH1_ENABLE : 0) |
+		(fsl_ldb_is_dual(fsl_ldb) ? LDB_CTRL_SPLIT_MODE : 0);
+
+	if (lvds_format_24bpp)
+		reg |=	(fsl_ldb->ch0_enabled ? LDB_CTRL_CH0_DATA_WIDTH : 0) |
+			(fsl_ldb->ch1_enabled ? LDB_CTRL_CH1_DATA_WIDTH : 0);
+
+	if (lvds_format_jeida)
+		reg |=	(fsl_ldb->ch0_enabled ? LDB_CTRL_CH0_BIT_MAPPING : 0) |
+			(fsl_ldb->ch1_enabled ? LDB_CTRL_CH1_BIT_MAPPING : 0);
+
+	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
+		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);
+
+	if (fsl_ldb->devdata->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);
+
+	/* Wait for VBG to stabilize. */
+	usleep_range(15, 20);
+
+	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);
+}
+
+static void fsl_ldb_atomic_disable(struct drm_bridge *bridge,
+				   struct drm_bridge_state *old_bridge_state)
+{
+	struct fsl_ldb *fsl_ldb = to_fsl_ldb(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,
+			     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);
+
+	clk_disable_unprepare(fsl_ldb->clk);
+}
+
+#define MAX_INPUT_SEL_FORMATS 1
+static u32 *
+fsl_ldb_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+				  struct drm_bridge_state *bridge_state,
+				  struct drm_crtc_state *crtc_state,
+				  struct drm_connector_state *conn_state,
+				  u32 output_fmt,
+				  unsigned int *num_input_fmts)
+{
+	u32 *input_fmts;
+
+	*num_input_fmts = 0;
+
+	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
+			     GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+
+	input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
+	*num_input_fmts = MAX_INPUT_SEL_FORMATS;
+
+	return input_fmts;
+}
+
+static enum drm_mode_status
+fsl_ldb_mode_valid(struct drm_bridge *bridge,
+		   const struct drm_display_info *info,
+		   const struct drm_display_mode *mode)
+{
+	struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge);
+
+	if (mode->clock > (fsl_ldb_is_dual(fsl_ldb) ? 160000 : 80000))
+		return MODE_CLOCK_HIGH;
+
+	return MODE_OK;
+}
+
+static const struct drm_bridge_funcs funcs = {
+	.attach = fsl_ldb_attach,
+	.atomic_enable = fsl_ldb_atomic_enable,
+	.atomic_disable = fsl_ldb_atomic_disable,
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_get_input_bus_fmts = fsl_ldb_atomic_get_input_bus_fmts,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.mode_valid = fsl_ldb_mode_valid,
+};
+
+static int fsl_ldb_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *panel_node;
+	struct device_node *remote1, *remote2;
+	struct drm_panel *panel;
+	struct fsl_ldb *fsl_ldb;
+	int dual_link;
+
+	fsl_ldb = devm_kzalloc(dev, sizeof(*fsl_ldb), GFP_KERNEL);
+	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;
+
+	fsl_ldb->clk = devm_clk_get(dev, "ldb");
+	if (IS_ERR(fsl_ldb->clk))
+		return PTR_ERR(fsl_ldb->clk);
+
+	fsl_ldb->regmap = syscon_node_to_regmap(dev->of_node->parent);
+	if (IS_ERR(fsl_ldb->regmap))
+		return PTR_ERR(fsl_ldb->regmap);
+
+	/* Locate the remote ports and the panel node */
+	remote1 = of_graph_get_remote_node(dev->of_node, 1, 0);
+	remote2 = of_graph_get_remote_node(dev->of_node, 2, 0);
+	fsl_ldb->ch0_enabled = (remote1 != NULL);
+	fsl_ldb->ch1_enabled = (remote2 != NULL);
+	panel_node = of_node_get(remote1 ? remote1 : remote2);
+	of_node_put(remote1);
+	of_node_put(remote2);
+
+	if (!fsl_ldb->ch0_enabled && !fsl_ldb->ch1_enabled) {
+		of_node_put(panel_node);
+		return dev_err_probe(dev, -ENXIO, "No panel node found");
+	}
+
+	dev_dbg(dev, "Using %s\n",
+		fsl_ldb_is_dual(fsl_ldb) ? "dual-link mode" :
+		fsl_ldb->ch0_enabled ? "channel 0" : "channel 1");
+
+	panel = of_drm_find_panel(panel_node);
+	of_node_put(panel_node);
+	if (IS_ERR(panel))
+		return PTR_ERR(panel);
+
+	fsl_ldb->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
+	if (IS_ERR(fsl_ldb->panel_bridge))
+		return PTR_ERR(fsl_ldb->panel_bridge);
+
+
+	if (fsl_ldb_is_dual(fsl_ldb)) {
+		struct device_node *port1, *port2;
+
+		port1 = of_graph_get_port_by_id(dev->of_node, 1);
+		port2 = of_graph_get_port_by_id(dev->of_node, 2);
+		dual_link = drm_of_lvds_get_dual_link_pixel_order(port1, port2);
+		of_node_put(port1);
+		of_node_put(port2);
+
+		if (dual_link < 0)
+			return dev_err_probe(dev, dual_link,
+					     "Error getting dual link configuration\n");
+
+		/* Only DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS is supported */
+		if (dual_link == DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS) {
+			dev_err(dev, "LVDS channel pixel swap not supported.\n");
+			return -EINVAL;
+		}
+	}
+
+	platform_set_drvdata(pdev, fsl_ldb);
+
+	drm_bridge_add(&fsl_ldb->bridge);
+
+	return 0;
+}
+
+static void fsl_ldb_remove(struct platform_device *pdev)
+{
+	struct fsl_ldb *fsl_ldb = platform_get_drvdata(pdev);
+
+	drm_bridge_remove(&fsl_ldb->bridge);
+}
+
+static const struct of_device_id fsl_ldb_match[] = {
+	{ .compatible = "fsl,imx6sx-ldb",
+	  .data = &fsl_ldb_devdata[IMX6SX_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);
+
+static struct platform_driver fsl_ldb_driver = {
+	.probe	= fsl_ldb_probe,
+	.remove_new = fsl_ldb_remove,
+	.driver		= {
+		.name		= "fsl-ldb",
+		.of_match_table	= fsl_ldb_match,
+	},
+};
+module_platform_driver(fsl_ldb_driver);
+
+MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
+MODULE_DESCRIPTION("Freescale i.MX8MP LDB");
+MODULE_LICENSE("GPL");