drivers/gpu/drm/omapdrm/displays/connector-dvi.c

   1 /*
   2  * Generic DVI Connector driver
   3  *
   4  * Copyright (C) 2013 Texas Instruments
   5  * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  */
  11
  12 #include <linux/i2c.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/slab.h>
  16
  17 #include <drm/drm_edid.h>
  18
  19 #include "../dss/omapdss.h"
  20
  21 static const struct videomode dvic_default_vm = {
  22         .hactive        = 640,
  23         .vactive        = 480,
  24
  25         .pixelclock     = 23500000,
  26
  27         .hfront_porch   = 48,
  28         .hsync_len      = 32,
  29         .hback_porch    = 80,
  30
  31         .vfront_porch   = 3,
  32         .vsync_len      = 4,
  33         .vback_porch    = 7,
  34
  35         .flags          = DISPLAY_FLAGS_HSYNC_HIGH | DISPLAY_FLAGS_VSYNC_HIGH |
  36                           DISPLAY_FLAGS_SYNC_NEGEDGE | DISPLAY_FLAGS_DE_HIGH |
  37                           DISPLAY_FLAGS_PIXDATA_POSEDGE,
  38 };
  39
  40 struct panel_drv_data {
  41         struct omap_dss_device dssdev;
  42         struct omap_dss_device *in;
  43
  44         struct videomode vm;
  45
  46         struct i2c_adapter *i2c_adapter;
  47 };
  48
  49 #define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
  50
  51 static int dvic_connect(struct omap_dss_device *dssdev)
  52 {
  53         struct panel_drv_data *ddata = to_panel_data(dssdev);
  54         struct omap_dss_device *in = ddata->in;
  55         int r;
  56
  57         if (omapdss_device_is_connected(dssdev))
  58                 return 0;
  59
  60         r = in->ops.dvi->connect(in, dssdev);
  61         if (r)
  62                 return r;
  63
  64         return 0;
  65 }
  66
  67 static void dvic_disconnect(struct omap_dss_device *dssdev)
  68 {
  69         struct panel_drv_data *ddata = to_panel_data(dssdev);
  70         struct omap_dss_device *in = ddata->in;
  71
  72         if (!omapdss_device_is_connected(dssdev))
  73                 return;
  74
  75         in->ops.dvi->disconnect(in, dssdev);
  76 }
  77
  78 static int dvic_enable(struct omap_dss_device *dssdev)
  79 {
  80         struct panel_drv_data *ddata = to_panel_data(dssdev);
  81         struct omap_dss_device *in = ddata->in;
  82         int r;
  83
  84         if (!omapdss_device_is_connected(dssdev))
  85                 return -ENODEV;
  86
  87         if (omapdss_device_is_enabled(dssdev))
  88                 return 0;
  89
  90         in->ops.dvi->set_timings(in, &ddata->vm);
  91
  92         r = in->ops.dvi->enable(in);
  93         if (r)
  94                 return r;
  95
  96         dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
  97
  98         return 0;
  99 }
 100
 101 static void dvic_disable(struct omap_dss_device *dssdev)
 102 {
 103         struct panel_drv_data *ddata = to_panel_data(dssdev);
 104         struct omap_dss_device *in = ddata->in;
 105
 106         if (!omapdss_device_is_enabled(dssdev))
 107                 return;
 108
 109         in->ops.dvi->disable(in);
 110
 111         dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
 112 }
 113
 114 static void dvic_set_timings(struct omap_dss_device *dssdev,
 115                              struct videomode *vm)
 116 {
 117         struct panel_drv_data *ddata = to_panel_data(dssdev);
 118         struct omap_dss_device *in = ddata->in;
 119
 120         ddata->vm = *vm;
 121         dssdev->panel.vm = *vm;
 122
 123         in->ops.dvi->set_timings(in, vm);
 124 }
 125
 126 static void dvic_get_timings(struct omap_dss_device *dssdev,
 127                              struct videomode *vm)
 128 {
 129         struct panel_drv_data *ddata = to_panel_data(dssdev);
 130
 131         *vm = ddata->vm;
 132 }
 133
 134 static int dvic_check_timings(struct omap_dss_device *dssdev,
 135                               struct videomode *vm)
 136 {
 137         struct panel_drv_data *ddata = to_panel_data(dssdev);
 138         struct omap_dss_device *in = ddata->in;
 139
 140         return in->ops.dvi->check_timings(in, vm);
 141 }
 142
 143 static int dvic_ddc_read(struct i2c_adapter *adapter,
 144                 unsigned char *buf, u16 count, u8 offset)
 145 {
 146         int r, retries;
 147
 148         for (retries = 3; retries > 0; retries--) {
 149                 struct i2c_msg msgs[] = {
 150                         {
 151                                 .addr   = DDC_ADDR,
 152                                 .flags  = 0,
 153                                 .len    = 1,
 154                                 .buf    = &offset,
 155                         }, {
 156                                 .addr   = DDC_ADDR,
 157                                 .flags  = I2C_M_RD,
 158                                 .len    = count,
 159                                 .buf    = buf,
 160                         }
 161                 };
 162
 163                 r = i2c_transfer(adapter, msgs, 2);
 164                 if (r == 2)
 165                         return 0;
 166
 167                 if (r != -EAGAIN)
 168                         break;
 169         }
 170
 171         return r < 0 ? r : -EIO;
 172 }
 173
 174 static int dvic_read_edid(struct omap_dss_device *dssdev,
 175                 u8 *edid, int len)
 176 {
 177         struct panel_drv_data *ddata = to_panel_data(dssdev);
 178         int r, l, bytes_read;
 179
 180         if (!ddata->i2c_adapter)
 181                 return -ENODEV;
 182
 183         l = min(EDID_LENGTH, len);
 184         r = dvic_ddc_read(ddata->i2c_adapter, edid, l, 0);
 185         if (r)
 186                 return r;
 187
 188         bytes_read = l;
 189
 190         /* if there are extensions, read second block */
 191         if (len > EDID_LENGTH && edid[0x7e] > 0) {
 192                 l = min(EDID_LENGTH, len - EDID_LENGTH);
 193
 194                 r = dvic_ddc_read(ddata->i2c_adapter, edid + EDID_LENGTH,
 195                                 l, EDID_LENGTH);
 196                 if (r)
 197                         return r;
 198
 199                 bytes_read += l;
 200         }
 201
 202         return bytes_read;
 203 }
 204
 205 static bool dvic_detect(struct omap_dss_device *dssdev)
 206 {
 207         struct panel_drv_data *ddata = to_panel_data(dssdev);
 208         unsigned char out;
 209         int r;
 210
 211         if (!ddata->i2c_adapter)
 212                 return true;
 213
 214         r = dvic_ddc_read(ddata->i2c_adapter, &out, 1, 0);
 215
 216         return r == 0;
 217 }
 218
 219 static struct omap_dss_driver dvic_driver = {
 220         .connect        = dvic_connect,
 221         .disconnect     = dvic_disconnect,
 222
 223         .enable         = dvic_enable,
 224         .disable        = dvic_disable,
 225
 226         .set_timings    = dvic_set_timings,
 227         .get_timings    = dvic_get_timings,
 228         .check_timings  = dvic_check_timings,
 229
 230         .read_edid      = dvic_read_edid,
 231         .detect         = dvic_detect,
 232 };
 233
 234 static int dvic_probe_of(struct platform_device *pdev)
 235 {
 236         struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 237         struct device_node *node = pdev->dev.of_node;
 238         struct omap_dss_device *in;
 239         struct device_node *adapter_node;
 240         struct i2c_adapter *adapter;
 241
 242         in = omapdss_of_find_source_for_first_ep(node);
 243         if (IS_ERR(in)) {
 244                 dev_err(&pdev->dev, "failed to find video source\n");
 245                 return PTR_ERR(in);
 246         }
 247
 248         ddata->in = in;
 249
 250         adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
 251         if (adapter_node) {
 252                 adapter = of_get_i2c_adapter_by_node(adapter_node);
 253                 of_node_put(adapter_node);
 254                 if (adapter == NULL) {
 255                         dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
 256                         omap_dss_put_device(ddata->in);
 257                         return -EPROBE_DEFER;
 258                 }
 259
 260                 ddata->i2c_adapter = adapter;
 261         }
 262
 263         return 0;
 264 }
 265
 266 static int dvic_probe(struct platform_device *pdev)
 267 {
 268         struct panel_drv_data *ddata;
 269         struct omap_dss_device *dssdev;
 270         int r;
 271
 272         ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
 273         if (!ddata)
 274                 return -ENOMEM;
 275
 276         platform_set_drvdata(pdev, ddata);
 277
 278         if (!pdev->dev.of_node)
 279                 return -ENODEV;
 280
 281         r = dvic_probe_of(pdev);
 282         if (r)
 283                 return r;
 284
 285         ddata->vm = dvic_default_vm;
 286
 287         dssdev = &ddata->dssdev;
 288         dssdev->driver = &dvic_driver;
 289         dssdev->dev = &pdev->dev;
 290         dssdev->type = OMAP_DISPLAY_TYPE_DVI;
 291         dssdev->owner = THIS_MODULE;
 292         dssdev->panel.vm = dvic_default_vm;
 293
 294         r = omapdss_register_display(dssdev);
 295         if (r) {
 296                 dev_err(&pdev->dev, "Failed to register panel\n");
 297                 goto err_reg;
 298         }
 299
 300         return 0;
 301
 302 err_reg:
 303         omap_dss_put_device(ddata->in);
 304
 305         i2c_put_adapter(ddata->i2c_adapter);
 306
 307         return r;
 308 }
 309
 310 static int __exit dvic_remove(struct platform_device *pdev)
 311 {
 312         struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 313         struct omap_dss_device *dssdev = &ddata->dssdev;
 314         struct omap_dss_device *in = ddata->in;
 315
 316         omapdss_unregister_display(&ddata->dssdev);
 317
 318         dvic_disable(dssdev);
 319         dvic_disconnect(dssdev);
 320
 321         omap_dss_put_device(in);
 322
 323         i2c_put_adapter(ddata->i2c_adapter);
 324
 325         return 0;
 326 }
 327
 328 static const struct of_device_id dvic_of_match[] = {
 329         { .compatible = "omapdss,dvi-connector", },
 330         {},
 331 };
 332
 333 MODULE_DEVICE_TABLE(of, dvic_of_match);
 334
 335 static struct platform_driver dvi_connector_driver = {
 336         .probe  = dvic_probe,
 337         .remove = __exit_p(dvic_remove),
 338         .driver = {
 339                 .name   = "connector-dvi",
 340                 .of_match_table = dvic_of_match,
 341                 .suppress_bind_attrs = true,
 342         },
 343 };
 344
 345 module_platform_driver(dvi_connector_driver);
 346
 347 MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
 348 MODULE_DESCRIPTION("Generic DVI Connector driver");
 349 MODULE_LICENSE("GPL");