linux/drivers/gpu/drm/omapdrm/displays/connector-dvi.c
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   1/*
   2 * Generic DVI Connector driver
   3 *
   4 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
   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/gpio/consumer.h>
  13#include <linux/i2c.h>
  14#include <linux/module.h>
  15#include <linux/platform_device.h>
  16#include <linux/slab.h>
  17
  18#include <drm/drm_edid.h>
  19
  20#include "../dss/omapdss.h"
  21
  22static const struct videomode dvic_default_vm = {
  23        .hactive        = 640,
  24        .vactive        = 480,
  25
  26        .pixelclock     = 23500000,
  27
  28        .hfront_porch   = 48,
  29        .hsync_len      = 32,
  30        .hback_porch    = 80,
  31
  32        .vfront_porch   = 3,
  33        .vsync_len      = 4,
  34        .vback_porch    = 7,
  35
  36        .flags          = DISPLAY_FLAGS_HSYNC_HIGH | DISPLAY_FLAGS_VSYNC_HIGH |
  37                          DISPLAY_FLAGS_SYNC_NEGEDGE | DISPLAY_FLAGS_DE_HIGH |
  38                          DISPLAY_FLAGS_PIXDATA_POSEDGE,
  39};
  40
  41struct panel_drv_data {
  42        struct omap_dss_device dssdev;
  43        struct omap_dss_device *in;
  44
  45        struct videomode vm;
  46
  47        struct i2c_adapter *i2c_adapter;
  48
  49        struct gpio_desc *hpd_gpio;
  50
  51        void (*hpd_cb)(void *cb_data, enum drm_connector_status status);
  52        void *hpd_cb_data;
  53        bool hpd_enabled;
  54        /* mutex for hpd fields above */
  55        struct mutex hpd_lock;
  56};
  57
  58#define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
  59
  60static int dvic_connect(struct omap_dss_device *dssdev)
  61{
  62        struct panel_drv_data *ddata = to_panel_data(dssdev);
  63        struct omap_dss_device *in;
  64        int r;
  65
  66        if (omapdss_device_is_connected(dssdev))
  67                return 0;
  68
  69        in = omapdss_of_find_source_for_first_ep(dssdev->dev->of_node);
  70        if (IS_ERR(in)) {
  71                dev_err(dssdev->dev, "failed to find video source\n");
  72                return PTR_ERR(in);
  73        }
  74
  75        r = in->ops.dvi->connect(in, dssdev);
  76        if (r) {
  77                omap_dss_put_device(in);
  78                return r;
  79        }
  80
  81        ddata->in = in;
  82        return 0;
  83}
  84
  85static void dvic_disconnect(struct omap_dss_device *dssdev)
  86{
  87        struct panel_drv_data *ddata = to_panel_data(dssdev);
  88        struct omap_dss_device *in = ddata->in;
  89
  90        if (!omapdss_device_is_connected(dssdev))
  91                return;
  92
  93        in->ops.dvi->disconnect(in, dssdev);
  94
  95        omap_dss_put_device(in);
  96        ddata->in = NULL;
  97}
  98
  99static int dvic_enable(struct omap_dss_device *dssdev)
 100{
 101        struct panel_drv_data *ddata = to_panel_data(dssdev);
 102        struct omap_dss_device *in = ddata->in;
 103        int r;
 104
 105        if (!omapdss_device_is_connected(dssdev))
 106                return -ENODEV;
 107
 108        if (omapdss_device_is_enabled(dssdev))
 109                return 0;
 110
 111        in->ops.dvi->set_timings(in, &ddata->vm);
 112
 113        r = in->ops.dvi->enable(in);
 114        if (r)
 115                return r;
 116
 117        dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
 118
 119        return 0;
 120}
 121
 122static void dvic_disable(struct omap_dss_device *dssdev)
 123{
 124        struct panel_drv_data *ddata = to_panel_data(dssdev);
 125        struct omap_dss_device *in = ddata->in;
 126
 127        if (!omapdss_device_is_enabled(dssdev))
 128                return;
 129
 130        in->ops.dvi->disable(in);
 131
 132        dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
 133}
 134
 135static void dvic_set_timings(struct omap_dss_device *dssdev,
 136                             struct videomode *vm)
 137{
 138        struct panel_drv_data *ddata = to_panel_data(dssdev);
 139        struct omap_dss_device *in = ddata->in;
 140
 141        ddata->vm = *vm;
 142        dssdev->panel.vm = *vm;
 143
 144        in->ops.dvi->set_timings(in, vm);
 145}
 146
 147static void dvic_get_timings(struct omap_dss_device *dssdev,
 148                             struct videomode *vm)
 149{
 150        struct panel_drv_data *ddata = to_panel_data(dssdev);
 151
 152        *vm = ddata->vm;
 153}
 154
 155static int dvic_check_timings(struct omap_dss_device *dssdev,
 156                              struct videomode *vm)
 157{
 158        struct panel_drv_data *ddata = to_panel_data(dssdev);
 159        struct omap_dss_device *in = ddata->in;
 160
 161        return in->ops.dvi->check_timings(in, vm);
 162}
 163
 164static int dvic_ddc_read(struct i2c_adapter *adapter,
 165                unsigned char *buf, u16 count, u8 offset)
 166{
 167        int r, retries;
 168
 169        for (retries = 3; retries > 0; retries--) {
 170                struct i2c_msg msgs[] = {
 171                        {
 172                                .addr   = DDC_ADDR,
 173                                .flags  = 0,
 174                                .len    = 1,
 175                                .buf    = &offset,
 176                        }, {
 177                                .addr   = DDC_ADDR,
 178                                .flags  = I2C_M_RD,
 179                                .len    = count,
 180                                .buf    = buf,
 181                        }
 182                };
 183
 184                r = i2c_transfer(adapter, msgs, 2);
 185                if (r == 2)
 186                        return 0;
 187
 188                if (r != -EAGAIN)
 189                        break;
 190        }
 191
 192        return r < 0 ? r : -EIO;
 193}
 194
 195static int dvic_read_edid(struct omap_dss_device *dssdev,
 196                u8 *edid, int len)
 197{
 198        struct panel_drv_data *ddata = to_panel_data(dssdev);
 199        int r, l, bytes_read;
 200
 201        if (ddata->hpd_gpio && !gpiod_get_value_cansleep(ddata->hpd_gpio))
 202                return -ENODEV;
 203
 204        if (!ddata->i2c_adapter)
 205                return -ENODEV;
 206
 207        l = min(EDID_LENGTH, len);
 208        r = dvic_ddc_read(ddata->i2c_adapter, edid, l, 0);
 209        if (r)
 210                return r;
 211
 212        bytes_read = l;
 213
 214        /* if there are extensions, read second block */
 215        if (len > EDID_LENGTH && edid[0x7e] > 0) {
 216                l = min(EDID_LENGTH, len - EDID_LENGTH);
 217
 218                r = dvic_ddc_read(ddata->i2c_adapter, edid + EDID_LENGTH,
 219                                l, EDID_LENGTH);
 220                if (r)
 221                        return r;
 222
 223                bytes_read += l;
 224        }
 225
 226        return bytes_read;
 227}
 228
 229static bool dvic_detect(struct omap_dss_device *dssdev)
 230{
 231        struct panel_drv_data *ddata = to_panel_data(dssdev);
 232        unsigned char out;
 233        int r;
 234
 235        if (ddata->hpd_gpio)
 236                return gpiod_get_value_cansleep(ddata->hpd_gpio);
 237
 238        if (!ddata->i2c_adapter)
 239                return true;
 240
 241        r = dvic_ddc_read(ddata->i2c_adapter, &out, 1, 0);
 242
 243        return r == 0;
 244}
 245
 246static int dvic_register_hpd_cb(struct omap_dss_device *dssdev,
 247                                 void (*cb)(void *cb_data,
 248                                            enum drm_connector_status status),
 249                                 void *cb_data)
 250{
 251        struct panel_drv_data *ddata = to_panel_data(dssdev);
 252
 253        if (!ddata->hpd_gpio)
 254                return -ENOTSUPP;
 255
 256        mutex_lock(&ddata->hpd_lock);
 257        ddata->hpd_cb = cb;
 258        ddata->hpd_cb_data = cb_data;
 259        mutex_unlock(&ddata->hpd_lock);
 260        return 0;
 261}
 262
 263static void dvic_unregister_hpd_cb(struct omap_dss_device *dssdev)
 264{
 265        struct panel_drv_data *ddata = to_panel_data(dssdev);
 266
 267        if (!ddata->hpd_gpio)
 268                return;
 269
 270        mutex_lock(&ddata->hpd_lock);
 271        ddata->hpd_cb = NULL;
 272        ddata->hpd_cb_data = NULL;
 273        mutex_unlock(&ddata->hpd_lock);
 274}
 275
 276static void dvic_enable_hpd(struct omap_dss_device *dssdev)
 277{
 278        struct panel_drv_data *ddata = to_panel_data(dssdev);
 279
 280        if (!ddata->hpd_gpio)
 281                return;
 282
 283        mutex_lock(&ddata->hpd_lock);
 284        ddata->hpd_enabled = true;
 285        mutex_unlock(&ddata->hpd_lock);
 286}
 287
 288static void dvic_disable_hpd(struct omap_dss_device *dssdev)
 289{
 290        struct panel_drv_data *ddata = to_panel_data(dssdev);
 291
 292        if (!ddata->hpd_gpio)
 293                return;
 294
 295        mutex_lock(&ddata->hpd_lock);
 296        ddata->hpd_enabled = false;
 297        mutex_unlock(&ddata->hpd_lock);
 298}
 299
 300static struct omap_dss_driver dvic_driver = {
 301        .connect        = dvic_connect,
 302        .disconnect     = dvic_disconnect,
 303
 304        .enable         = dvic_enable,
 305        .disable        = dvic_disable,
 306
 307        .set_timings    = dvic_set_timings,
 308        .get_timings    = dvic_get_timings,
 309        .check_timings  = dvic_check_timings,
 310
 311        .read_edid      = dvic_read_edid,
 312        .detect         = dvic_detect,
 313
 314        .register_hpd_cb        = dvic_register_hpd_cb,
 315        .unregister_hpd_cb      = dvic_unregister_hpd_cb,
 316        .enable_hpd             = dvic_enable_hpd,
 317        .disable_hpd            = dvic_disable_hpd,
 318};
 319
 320static irqreturn_t dvic_hpd_isr(int irq, void *data)
 321{
 322        struct panel_drv_data *ddata = data;
 323
 324        mutex_lock(&ddata->hpd_lock);
 325        if (ddata->hpd_enabled && ddata->hpd_cb) {
 326                enum drm_connector_status status;
 327
 328                if (dvic_detect(&ddata->dssdev))
 329                        status = connector_status_connected;
 330                else
 331                        status = connector_status_disconnected;
 332
 333                ddata->hpd_cb(ddata->hpd_cb_data, status);
 334        }
 335        mutex_unlock(&ddata->hpd_lock);
 336
 337        return IRQ_HANDLED;
 338}
 339
 340static int dvic_probe_of(struct platform_device *pdev)
 341{
 342        struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 343        struct device_node *node = pdev->dev.of_node;
 344        struct device_node *adapter_node;
 345        struct i2c_adapter *adapter;
 346        struct gpio_desc *gpio;
 347        int r;
 348
 349        gpio = devm_gpiod_get_optional(&pdev->dev, "hpd", GPIOD_IN);
 350        if (IS_ERR(gpio)) {
 351                dev_err(&pdev->dev, "failed to parse HPD gpio\n");
 352                return PTR_ERR(gpio);
 353        }
 354
 355        ddata->hpd_gpio = gpio;
 356
 357        mutex_init(&ddata->hpd_lock);
 358
 359        if (ddata->hpd_gpio) {
 360                r = devm_request_threaded_irq(&pdev->dev,
 361                        gpiod_to_irq(ddata->hpd_gpio), NULL, dvic_hpd_isr,
 362                        IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 363                        "DVI HPD", ddata);
 364                if (r)
 365                        return r;
 366        }
 367
 368        adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
 369        if (adapter_node) {
 370                adapter = of_get_i2c_adapter_by_node(adapter_node);
 371                of_node_put(adapter_node);
 372                if (adapter == NULL) {
 373                        dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
 374                        return -EPROBE_DEFER;
 375                }
 376
 377                ddata->i2c_adapter = adapter;
 378        }
 379
 380        return 0;
 381}
 382
 383static int dvic_probe(struct platform_device *pdev)
 384{
 385        struct panel_drv_data *ddata;
 386        struct omap_dss_device *dssdev;
 387        int r;
 388
 389        ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
 390        if (!ddata)
 391                return -ENOMEM;
 392
 393        platform_set_drvdata(pdev, ddata);
 394
 395        r = dvic_probe_of(pdev);
 396        if (r)
 397                return r;
 398
 399        ddata->vm = dvic_default_vm;
 400
 401        dssdev = &ddata->dssdev;
 402        dssdev->driver = &dvic_driver;
 403        dssdev->dev = &pdev->dev;
 404        dssdev->type = OMAP_DISPLAY_TYPE_DVI;
 405        dssdev->owner = THIS_MODULE;
 406        dssdev->panel.vm = dvic_default_vm;
 407
 408        r = omapdss_register_display(dssdev);
 409        if (r) {
 410                dev_err(&pdev->dev, "Failed to register panel\n");
 411                goto err_reg;
 412        }
 413
 414        return 0;
 415
 416err_reg:
 417        i2c_put_adapter(ddata->i2c_adapter);
 418        mutex_destroy(&ddata->hpd_lock);
 419
 420        return r;
 421}
 422
 423static int __exit dvic_remove(struct platform_device *pdev)
 424{
 425        struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 426        struct omap_dss_device *dssdev = &ddata->dssdev;
 427
 428        omapdss_unregister_display(&ddata->dssdev);
 429
 430        dvic_disable(dssdev);
 431        dvic_disconnect(dssdev);
 432
 433        i2c_put_adapter(ddata->i2c_adapter);
 434
 435        mutex_destroy(&ddata->hpd_lock);
 436
 437        return 0;
 438}
 439
 440static const struct of_device_id dvic_of_match[] = {
 441        { .compatible = "omapdss,dvi-connector", },
 442        {},
 443};
 444
 445MODULE_DEVICE_TABLE(of, dvic_of_match);
 446
 447static struct platform_driver dvi_connector_driver = {
 448        .probe  = dvic_probe,
 449        .remove = __exit_p(dvic_remove),
 450        .driver = {
 451                .name   = "connector-dvi",
 452                .of_match_table = dvic_of_match,
 453                .suppress_bind_attrs = true,
 454        },
 455};
 456
 457module_platform_driver(dvi_connector_driver);
 458
 459MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
 460MODULE_DESCRIPTION("Generic DVI Connector driver");
 461MODULE_LICENSE("GPL");
 462