kernel/drivers/gpu/drm/tilcdc/tilcdc_external.c

   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
  17 static 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
  30 static 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
  55 static 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
  97 int 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
 119 void 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
 133 static int dev_match_of(struct device *dev, void *data)
 134 {
 135         return dev->of_node == data;
 136 }
 137
 138 int 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 }