1/*
  2 * Copyright (C) 2015 Texas Instruments
  3 * Author: Jyri Sarha <jsarha@ti.com>
  4 *
  5 * This program is free software; you can redistribute it and/or modify it
  6 * under the terms of the GNU General Public License version 2 as published by
  7 * the Free Software Foundation.
  8 *
  9 */
 10
 11#include <linux/component.h>
 12#include <linux/of_graph.h>
 13
 14#include "tilcdc_drv.h"
 15#include "tilcdc_external.h"
 16
 17static const struct tilcdc_panel_info panel_info_tda998x = {
 18		.ac_bias                = 255,
 19		.ac_bias_intrpt         = 0,
 20		.dma_burst_sz           = 16,
 21		.bpp                    = 16,
 22		.fdd                    = 0x80,
 23		.tft_alt_mode           = 0,
 24		.invert_pxl_clk		= 1,
 25		.sync_edge              = 1,
 26		.sync_ctrl              = 1,
 27		.raster_order           = 0,
 28};
 29
 30static int tilcdc_external_mode_valid(struct drm_connector *connector,
 31				      struct drm_display_mode *mode)
 32{
 33	struct tilcdc_drm_private *priv = connector->dev->dev_private;
 34	int ret, i;
 35
 36	ret = tilcdc_crtc_mode_valid(priv->crtc, mode);
 37	if (ret != MODE_OK)
 38		return ret;
 39
 40	for (i = 0; i < priv->num_connectors &&
 41		     priv->connectors[i] != connector; i++)
 42		;
 43
 44	BUG_ON(priv->connectors[i] != connector);
 45	BUG_ON(!priv->connector_funcs[i]);
 46
 47	/* If the connector has its own mode_valid call it. */
 48	if (!IS_ERR(priv->connector_funcs[i]) &&
 49	    priv->connector_funcs[i]->mode_valid)
 50		return priv->connector_funcs[i]->mode_valid(connector, mode);
 51
 52	return MODE_OK;
 53}
 54
 55static int tilcdc_add_external_encoder(struct drm_device *dev, int *bpp,
 56				       struct drm_connector *connector)
 57{
 58	struct tilcdc_drm_private *priv = dev->dev_private;
 59	struct drm_connector_helper_funcs *connector_funcs;
 60
 61	priv->connectors[priv->num_connectors] = connector;
 62	priv->encoders[priv->num_encoders++] = connector->encoder;
 63
 64	/* Only tda998x is supported at the moment. */
 65	tilcdc_crtc_set_simulate_vesa_sync(priv->crtc, true);
 66	tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_tda998x);
 67	*bpp = panel_info_tda998x.bpp;
 68
 69	connector_funcs = devm_kzalloc(dev->dev, sizeof(*connector_funcs),
 70				       GFP_KERNEL);
 71	if (!connector_funcs)
 72		return -ENOMEM;
 73
 74	/* connector->helper_private contains always struct
 75	 * connector_helper_funcs pointer. For tilcdc crtc to have a
 76	 * say if a specific mode is Ok, we need to install our own
 77	 * helper functions. In our helper functions we copy
 78	 * everything else but use our own mode_valid() (above).
 79	 */
 80	if (connector->helper_private) {
 81		priv->connector_funcs[priv->num_connectors] =
 82			connector->helper_private;
 83		*connector_funcs = *priv->connector_funcs[priv->num_connectors];
 84	} else {
 85		priv->connector_funcs[priv->num_connectors] = ERR_PTR(-ENOENT);
 86	}
 87	connector_funcs->mode_valid = tilcdc_external_mode_valid;
 88	drm_connector_helper_add(connector, connector_funcs);
 89	priv->num_connectors++;
 90
 91	dev_dbg(dev->dev, "External encoder '%s' connected\n",
 92		connector->encoder->name);
 93
 94	return 0;
 95}
 96
 97int tilcdc_add_external_encoders(struct drm_device *dev, int *bpp)
 98{
 99	struct tilcdc_drm_private *priv = dev->dev_private;
100	struct drm_connector *connector;
101	int num_internal_connectors = priv->num_connectors;
102
103	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
104		bool found = false;
105		int i, ret;
106
107		for (i = 0; i < num_internal_connectors; i++)
108			if (connector == priv->connectors[i])
109				found = true;
110		if (!found) {
111			ret = tilcdc_add_external_encoder(dev, bpp, connector);
112			if (ret)
113				return ret;
114		}
115	}
116	return 0;
117}
118
119void tilcdc_remove_external_encoders(struct drm_device *dev)
120{
121	struct tilcdc_drm_private *priv = dev->dev_private;
122	int i;
123
124	/* Restore the original helper functions, if any. */
125	for (i = 0; i < priv->num_connectors; i++)
126		if (IS_ERR(priv->connector_funcs[i]))
127			drm_connector_helper_add(priv->connectors[i], NULL);
128		else if (priv->connector_funcs[i])
129			drm_connector_helper_add(priv->connectors[i],
130						 priv->connector_funcs[i]);
131}
132
133static int dev_match_of(struct device *dev, void *data)
134{
135	return dev->of_node == data;
136}
137
138int tilcdc_get_external_components(struct device *dev,
139				   struct component_match **match)
140{
141	struct device_node *ep = NULL;
142	int count = 0;
143
144	while ((ep = of_graph_get_next_endpoint(dev->of_node, ep))) {
145		struct device_node *node;
146
147		node = of_graph_get_remote_port_parent(ep);
148		if (!node && !of_device_is_available(node)) {
149			of_node_put(node);
150			continue;
151		}
152
153		dev_dbg(dev, "Subdevice node '%s' found\n", node->name);
154		if (match)
155			component_match_add(dev, match, dev_match_of, node);
156		of_node_put(node);
157		count++;
158	}
159
160	if (count > 1) {
161		dev_err(dev, "Only one external encoder is supported\n");
162		return -EINVAL;
163	}
164
165	return count;
166}