1 files changed, 598 insertions, 0 deletions

diff --git a/drivers/gpu/drm/tidss/tidss_oldi.c b/drivers/gpu/drm/tidss/tidss_oldi.c
new file mode 100644
index 000000000000..8f25159d0666
--- /dev/null
+++ b/drivers/gpu/drm/tidss/tidss_oldi.c
@@ -0,0 +1,598 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2025 - Texas Instruments Incorporated
+ *
+ * Aradhya Bhatia <a-bhatia1@ti.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/mfd/syscon.h>
+#include <linux/media-bus-format.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_of.h>
+
+#include "tidss_dispc.h"
+#include "tidss_dispc_regs.h"
+#include "tidss_oldi.h"
+
+struct tidss_oldi {
+	struct tidss_device	*tidss;
+	struct device		*dev;
+
+	struct drm_bridge	bridge;
+	struct drm_bridge	*next_bridge;
+
+	enum tidss_oldi_link_type link_type;
+	const struct oldi_bus_format *bus_format;
+	u32 oldi_instance;
+	int companion_instance;	/* -1 when OLDI TX operates in Single-Link */
+	u32 parent_vp;
+
+	struct clk *serial;
+	struct regmap *io_ctrl;
+};
+
+struct oldi_bus_format {
+	u32 bus_fmt;
+	u32 data_width;
+	enum oldi_mode_reg_val oldi_mode_reg_val;
+	u32 input_bus_fmt;
+};
+
+static const struct oldi_bus_format oldi_bus_formats[] = {
+	{ MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,	18, SPWG_18,	MEDIA_BUS_FMT_RGB666_1X18 },
+	{ MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,	24, SPWG_24,	MEDIA_BUS_FMT_RGB888_1X24 },
+	{ MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA,	24, JEIDA_24,	MEDIA_BUS_FMT_RGB888_1X24 },
+};
+
+#define OLDI_IDLE_CLK_HZ	25000000 /*25 MHz */
+
+static inline struct tidss_oldi *
+drm_bridge_to_tidss_oldi(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct tidss_oldi, bridge);
+}
+
+static int tidss_oldi_bridge_attach(struct drm_bridge *bridge,
+				    struct drm_encoder *encoder,
+				    enum drm_bridge_attach_flags flags)
+{
+	struct tidss_oldi *oldi = drm_bridge_to_tidss_oldi(bridge);
+
+	if (!oldi->next_bridge) {
+		dev_err(oldi->dev,
+			"%s: OLDI%u Failure attach next bridge\n",
+			__func__, oldi->oldi_instance);
+		return -ENODEV;
+	}
+
+	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
+		dev_err(oldi->dev,
+			"%s: OLDI%u DRM_BRIDGE_ATTACH_NO_CONNECTOR is mandatory.\n",
+			__func__, oldi->oldi_instance);
+		return -EINVAL;
+	}
+
+	return drm_bridge_attach(encoder, oldi->next_bridge, bridge, flags);
+}
+
+static int
+tidss_oldi_set_serial_clk(struct tidss_oldi *oldi, unsigned long rate)
+{
+	unsigned long new_rate;
+	int ret;
+
+	ret = clk_set_rate(oldi->serial, rate);
+	if (ret) {
+		dev_err(oldi->dev,
+			"OLDI%u: failed to set serial clk rate to %lu Hz\n",
+			 oldi->oldi_instance, rate);
+		return ret;
+	}
+
+	new_rate = clk_get_rate(oldi->serial);
+
+	if (dispc_pclk_diff(rate, new_rate) > 5)
+		dev_warn(oldi->dev,
+			 "OLDI%u Clock rate %lu differs over 5%% from requested %lu\n",
+			 oldi->oldi_instance, new_rate, rate);
+
+	dev_dbg(oldi->dev, "OLDI%u: new rate %lu Hz (requested %lu Hz)\n",
+		oldi->oldi_instance, clk_get_rate(oldi->serial), rate);
+
+	return 0;
+}
+
+static void tidss_oldi_tx_power(struct tidss_oldi *oldi, bool enable)
+{
+	u32 mask;
+
+	/*
+	 * The power control bits are Active Low, and remain powered off by
+	 * default. That is, the bits are set to 1. To power on the OLDI TXes,
+	 * the bits must be cleared to 0. Since there are cases where not all
+	 * OLDI TXes are being used, the power logic selectively powers them
+	 * on.
+	 * Setting the variable 'val' to particular bit masks, makes sure that
+	 * the undesired OLDI TXes remain powered off.
+	 */
+
+	if (enable) {
+		switch (oldi->link_type) {
+		case OLDI_MODE_SINGLE_LINK:
+			/* Power-on only the required OLDI TX's IO*/
+			mask = OLDI_PWRDOWN_TX(oldi->oldi_instance) | OLDI_PWRDN_BG;
+			break;
+		case OLDI_MODE_CLONE_SINGLE_LINK:
+		case OLDI_MODE_DUAL_LINK:
+			/* Power-on both the OLDI TXes' IOs */
+			mask = OLDI_PWRDOWN_TX(oldi->oldi_instance) |
+			       OLDI_PWRDOWN_TX(oldi->companion_instance) |
+			       OLDI_PWRDN_BG;
+			break;
+		default:
+			/*
+			 * This code execution should never reach here as any
+			 * OLDI with an unsupported OLDI mode would never get
+			 * registered in the first place.
+			 * However, power-off the OLDI in concern just in case.
+			 */
+			mask = OLDI_PWRDOWN_TX(oldi->oldi_instance);
+			enable = false;
+			break;
+		}
+	} else {
+		switch (oldi->link_type) {
+		case OLDI_MODE_CLONE_SINGLE_LINK:
+		case OLDI_MODE_DUAL_LINK:
+			mask = OLDI_PWRDOWN_TX(oldi->oldi_instance) |
+			       OLDI_PWRDOWN_TX(oldi->companion_instance) |
+			       OLDI_PWRDN_BG;
+			break;
+		case OLDI_MODE_SINGLE_LINK:
+		default:
+			mask = OLDI_PWRDOWN_TX(oldi->oldi_instance);
+			break;
+		}
+	}
+
+	regmap_update_bits(oldi->io_ctrl, OLDI_PD_CTRL, mask, enable ? 0 : mask);
+}
+
+static int tidss_oldi_config(struct tidss_oldi *oldi)
+{
+	const struct oldi_bus_format *bus_fmt = NULL;
+	u32 oldi_cfg = 0;
+	int ret;
+
+	bus_fmt = oldi->bus_format;
+
+	/*
+	 * MASTERSLAVE and SRC bits of OLDI Config are always set to 0.
+	 */
+
+	if (bus_fmt->data_width == 24)
+		oldi_cfg |= OLDI_MSB;
+	else if (bus_fmt->data_width != 18)
+		dev_warn(oldi->dev,
+			 "OLDI%u: DSS port width %d not supported\n",
+			 oldi->oldi_instance, bus_fmt->data_width);
+
+	oldi_cfg |= OLDI_DEPOL;
+
+	oldi_cfg = (oldi_cfg & (~OLDI_MAP)) | (bus_fmt->oldi_mode_reg_val << 1);
+
+	oldi_cfg |= OLDI_SOFTRST;
+
+	oldi_cfg |= OLDI_ENABLE;
+
+	switch (oldi->link_type) {
+	case OLDI_MODE_SINGLE_LINK:
+		/* All configuration is done for this mode.  */
+		break;
+
+	case OLDI_MODE_CLONE_SINGLE_LINK:
+		oldi_cfg |= OLDI_CLONE_MODE;
+		break;
+
+	case OLDI_MODE_DUAL_LINK:
+		/* data-mapping field also indicates dual-link mode */
+		oldi_cfg |= BIT(3);
+		oldi_cfg |= OLDI_DUALMODESYNC;
+		break;
+
+	default:
+		dev_err(oldi->dev, "OLDI%u: Unsupported mode.\n",
+			oldi->oldi_instance);
+		return -EINVAL;
+	}
+
+	ret = tidss_configure_oldi(oldi->tidss, oldi->parent_vp, oldi_cfg);
+	if (ret == -ETIMEDOUT)
+		dev_warn(oldi->dev, "OLDI%u: timeout waiting for OLDI reset done.\n",
+			 oldi->oldi_instance);
+
+	return ret;
+}
+
+static void tidss_oldi_atomic_pre_enable(struct drm_bridge *bridge,
+					 struct drm_atomic_state *state)
+{
+	struct tidss_oldi *oldi = drm_bridge_to_tidss_oldi(bridge);
+	struct drm_connector *connector;
+	struct drm_connector_state *conn_state;
+	struct drm_crtc_state *crtc_state;
+	struct drm_display_mode *mode;
+
+	if (oldi->link_type == OLDI_MODE_SECONDARY_CLONE_SINGLE_LINK)
+		return;
+
+	connector = drm_atomic_get_new_connector_for_encoder(state,
+							     bridge->encoder);
+	if (WARN_ON(!connector))
+		return;
+
+	conn_state = drm_atomic_get_new_connector_state(state, connector);
+	if (WARN_ON(!conn_state))
+		return;
+
+	crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);
+	if (WARN_ON(!crtc_state))
+		return;
+
+	mode = &crtc_state->adjusted_mode;
+
+	/* Configure the OLDI params*/
+	tidss_oldi_config(oldi);
+
+	/* Set the OLDI serial clock (7 times the pixel clock) */
+	tidss_oldi_set_serial_clk(oldi, mode->clock * 7 * 1000);
+
+	/* Enable OLDI IO power */
+	tidss_oldi_tx_power(oldi, true);
+}
+
+static void tidss_oldi_atomic_post_disable(struct drm_bridge *bridge,
+					   struct drm_atomic_state *state)
+{
+	struct tidss_oldi *oldi = drm_bridge_to_tidss_oldi(bridge);
+
+	if (oldi->link_type == OLDI_MODE_SECONDARY_CLONE_SINGLE_LINK)
+		return;
+
+	/* Disable OLDI IO power */
+	tidss_oldi_tx_power(oldi, false);
+
+	/* Set the OLDI serial clock to IDLE Frequency */
+	tidss_oldi_set_serial_clk(oldi, OLDI_IDLE_CLK_HZ);
+
+	/* Clear OLDI Config */
+	tidss_disable_oldi(oldi->tidss, oldi->parent_vp);
+}
+
+#define MAX_INPUT_SEL_FORMATS	1
+
+static u32 *tidss_oldi_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)
+{
+	struct tidss_oldi *oldi = drm_bridge_to_tidss_oldi(bridge);
+	u32 *input_fmts;
+	int i;
+
+	*num_input_fmts = 0;
+
+	for (i = 0; i < ARRAY_SIZE(oldi_bus_formats); i++)
+		if (oldi_bus_formats[i].bus_fmt == output_fmt)
+			break;
+
+	if (i == ARRAY_SIZE(oldi_bus_formats))
+		return NULL;
+
+	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
+			     GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+
+	*num_input_fmts = 1;
+	input_fmts[0] = oldi_bus_formats[i].input_bus_fmt;
+	oldi->bus_format = &oldi_bus_formats[i];
+
+	return input_fmts;
+}
+
+static const struct drm_bridge_funcs tidss_oldi_bridge_funcs = {
+	.attach	= tidss_oldi_bridge_attach,
+	.atomic_pre_enable = tidss_oldi_atomic_pre_enable,
+	.atomic_post_disable = tidss_oldi_atomic_post_disable,
+	.atomic_get_input_bus_fmts = tidss_oldi_atomic_get_input_bus_fmts,
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+};
+
+static int get_oldi_mode(struct device_node *oldi_tx, int *companion_instance)
+{
+	struct device_node *companion;
+	struct device_node *port0, *port1;
+	u32 companion_reg;
+	bool secondary_oldi = false;
+	int pixel_order;
+
+	/*
+	 * Find if the OLDI is paired with another OLDI for combined OLDI
+	 * operation (dual-link or clone).
+	 */
+	companion = of_parse_phandle(oldi_tx, "ti,companion-oldi", 0);
+	if (!companion)
+		/*
+		 * The OLDI TX does not have a companion, nor is it a
+		 * secondary OLDI. It will operate independently.
+		 */
+		return OLDI_MODE_SINGLE_LINK;
+
+	if (of_property_read_u32(companion, "reg", &companion_reg))
+		return OLDI_MODE_UNSUPPORTED;
+
+	if (companion_reg > (TIDSS_MAX_OLDI_TXES - 1))
+		/* Invalid companion OLDI reg value. */
+		return OLDI_MODE_UNSUPPORTED;
+
+	*companion_instance = (int)companion_reg;
+
+	if (of_property_read_bool(oldi_tx, "ti,secondary-oldi"))
+		secondary_oldi = true;
+
+	/*
+	 * We need to work out if the sink is expecting us to function in
+	 * dual-link mode. We do this by looking at the DT port nodes, the
+	 * OLDI TX ports are connected to. If they are marked as expecting
+	 * even pixels and odd pixels, then we need to enable dual-link.
+	 */
+	port0 = of_graph_get_port_by_id(oldi_tx, 1);
+	port1 = of_graph_get_port_by_id(companion, 1);
+	pixel_order = drm_of_lvds_get_dual_link_pixel_order(port0, port1);
+	of_node_put(port0);
+	of_node_put(port1);
+	of_node_put(companion);
+
+	switch (pixel_order) {
+	case -EINVAL:
+		/*
+		 * The dual-link properties were not found in at least
+		 * one of the sink nodes. Since 2 OLDI ports are present
+		 * in the DT, it can be safely assumed that the required
+		 * configuration is Clone Mode.
+		 */
+		return (secondary_oldi ? OLDI_MODE_SECONDARY_CLONE_SINGLE_LINK :
+					 OLDI_MODE_CLONE_SINGLE_LINK);
+
+	case DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS:
+		/*
+		 * Primary OLDI can only support "ODD" pixels. So, from its
+		 * perspective, the pixel order has to be ODD-EVEN.
+		 */
+		return (secondary_oldi ? OLDI_MODE_UNSUPPORTED :
+					 OLDI_MODE_DUAL_LINK);
+
+	case DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS:
+		/*
+		 * Secondary OLDI can only support "EVEN" pixels. So, from its
+		 * perspective, the pixel order has to be EVEN-ODD.
+		 */
+		return (secondary_oldi ? OLDI_MODE_SECONDARY_DUAL_LINK :
+					 OLDI_MODE_UNSUPPORTED);
+
+	default:
+		return OLDI_MODE_UNSUPPORTED;
+	}
+}
+
+static int get_parent_dss_vp(struct device_node *oldi_tx, u32 *parent_vp)
+{
+	struct device_node *ep, *dss_port;
+	int ret;
+
+	ep = of_graph_get_endpoint_by_regs(oldi_tx, OLDI_INPUT_PORT, -1);
+	if (ep) {
+		dss_port = of_graph_get_remote_port(ep);
+		if (!dss_port) {
+			ret = -ENODEV;
+			goto err_return_ep_port;
+		}
+
+		ret = of_property_read_u32(dss_port, "reg", parent_vp);
+
+		of_node_put(dss_port);
+err_return_ep_port:
+		of_node_put(ep);
+		return ret;
+	}
+
+	return -ENODEV;
+}
+
+static const struct drm_bridge_timings default_tidss_oldi_timings = {
+	.input_bus_flags = DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
+			 | DRM_BUS_FLAG_DE_HIGH,
+};
+
+void tidss_oldi_deinit(struct tidss_device *tidss)
+{
+	for (int i = 0; i < tidss->num_oldis; i++) {
+		if (tidss->oldis[i]) {
+			drm_bridge_remove(&tidss->oldis[i]->bridge);
+			tidss->oldis[i] = NULL;
+		}
+	}
+}
+
+int tidss_oldi_init(struct tidss_device *tidss)
+{
+	struct tidss_oldi *oldi;
+	struct device_node *child;
+	struct drm_bridge *bridge;
+	u32 parent_vp, oldi_instance;
+	int companion_instance = -1;
+	enum tidss_oldi_link_type link_type = OLDI_MODE_UNSUPPORTED;
+	struct device_node *oldi_parent;
+	int ret = 0;
+
+	tidss->num_oldis = 0;
+
+	oldi_parent = of_get_child_by_name(tidss->dev->of_node, "oldi-transmitters");
+	if (!oldi_parent)
+		/* Return gracefully */
+		return 0;
+
+	for_each_available_child_of_node(oldi_parent, child) {
+		ret = get_parent_dss_vp(child, &parent_vp);
+		if (ret) {
+			if (ret == -ENODEV) {
+				/*
+				 * ENODEV means that this particular OLDI node
+				 * is not connected with the DSS, which is not
+				 * a harmful case. There could be another OLDI
+				 * which may still be connected.
+				 * Continue to search for that.
+				 */
+				ret = 0;
+				continue;
+			}
+			goto err_put_node;
+		}
+
+		ret = of_property_read_u32(child, "reg", &oldi_instance);
+		if (ret)
+			goto err_put_node;
+
+		/*
+		 * Now that it's confirmed that OLDI is connected with DSS,
+		 * let's continue getting the OLDI sinks ahead and other OLDI
+		 * properties.
+		 */
+		bridge = devm_drm_of_get_bridge(tidss->dev, child,
+						OLDI_OUTPUT_PORT, 0);
+		if (IS_ERR(bridge)) {
+			/*
+			 * Either there was no OLDI sink in the devicetree, or
+			 * the OLDI sink has not been added yet. In any case,
+			 * return.
+			 * We don't want to have an OLDI node connected to DSS
+			 * but not to any sink.
+			 */
+			ret = dev_err_probe(tidss->dev, PTR_ERR(bridge),
+					    "no panel/bridge for OLDI%u.\n",
+					    oldi_instance);
+			goto err_put_node;
+		}
+
+		link_type = get_oldi_mode(child, &companion_instance);
+		if (link_type == OLDI_MODE_UNSUPPORTED) {
+			ret = dev_err_probe(tidss->dev, -EINVAL,
+					    "OLDI%u: Unsupported OLDI connection.\n",
+					    oldi_instance);
+			goto err_put_node;
+		} else if ((link_type == OLDI_MODE_SECONDARY_CLONE_SINGLE_LINK) ||
+			   (link_type == OLDI_MODE_CLONE_SINGLE_LINK)) {
+			/*
+			 * The OLDI driver cannot support OLDI clone mode
+			 * properly at present.
+			 * The clone mode requires 2 working encoder-bridge
+			 * pipelines, generating from the same crtc. The DRM
+			 * framework does not support this at present. If
+			 * there were to be, say, 2 OLDI sink bridges each
+			 * connected to an OLDI TXes, they couldn't both be
+			 * supported simultaneously.
+			 * This driver still has some code pertaining to OLDI
+			 * clone mode configuration in DSS hardware for future,
+			 * when there is a better infrastructure in the DRM
+			 * framework to support 2 encoder-bridge pipelines
+			 * simultaneously.
+			 * Till that time, this driver shall error out if it
+			 * detects a clone mode configuration.
+			 */
+			ret = dev_err_probe(tidss->dev, -EOPNOTSUPP,
+					    "The OLDI driver does not support Clone Mode at present.\n");
+			goto err_put_node;
+		} else if (link_type == OLDI_MODE_SECONDARY_DUAL_LINK) {
+			/*
+			 * This is the secondary OLDI node, which serves as a
+			 * companion to the primary OLDI, when it is configured
+			 * for the dual-link mode. Since the primary OLDI will
+			 * be a part of bridge chain, no need to put this one
+			 * too. Continue onto the next OLDI node.
+			 */
+			continue;
+		}
+
+		oldi = devm_drm_bridge_alloc(tidss->dev, struct tidss_oldi, bridge,
+					     &tidss_oldi_bridge_funcs);
+		if (IS_ERR(oldi)) {
+			ret = PTR_ERR(oldi);
+			goto err_put_node;
+		}
+
+		oldi->parent_vp = parent_vp;
+		oldi->oldi_instance = oldi_instance;
+		oldi->companion_instance = companion_instance;
+		oldi->link_type = link_type;
+		oldi->dev = tidss->dev;
+		oldi->next_bridge = bridge;
+
+		/*
+		 * Only the primary OLDI needs to reference the io-ctrl system
+		 * registers, and the serial clock.
+		 * We don't require a check for secondary OLDI in dual-link mode
+		 * because the driver will not create a drm_bridge instance.
+		 * But the driver will need to create a drm_bridge instance,
+		 * for secondary OLDI in clone mode (once it is supported).
+		 */
+		if (link_type != OLDI_MODE_SECONDARY_CLONE_SINGLE_LINK) {
+			oldi->io_ctrl = syscon_regmap_lookup_by_phandle(child,
+									"ti,oldi-io-ctrl");
+			if (IS_ERR(oldi->io_ctrl)) {
+				ret = dev_err_probe(oldi->dev, PTR_ERR(oldi->io_ctrl),
+						    "OLDI%u: syscon_regmap_lookup_by_phandle failed.\n",
+						    oldi_instance);
+				goto err_put_node;
+			}
+
+			oldi->serial = of_clk_get_by_name(child, "serial");
+			if (IS_ERR(oldi->serial)) {
+				ret = dev_err_probe(oldi->dev, PTR_ERR(oldi->serial),
+						    "OLDI%u: Failed to get serial clock.\n",
+						    oldi_instance);
+				goto err_put_node;
+			}
+		}
+
+		/* Register the bridge. */
+		oldi->bridge.of_node = child;
+		oldi->bridge.driver_private = oldi;
+		oldi->bridge.timings = &default_tidss_oldi_timings;
+
+		tidss->oldis[tidss->num_oldis++] = oldi;
+		oldi->tidss = tidss;
+
+		drm_bridge_add(&oldi->bridge);
+	}
+
+	of_node_put(child);
+	of_node_put(oldi_parent);
+
+	return 0;
+
+err_put_node:
+	of_node_put(child);
+	of_node_put(oldi_parent);
+	return ret;
+}