linux/drivers/gpu/drm/bridge/parade-ps8622.c
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   1/*
   2 * Parade PS8622 eDP/LVDS bridge driver
   3 *
   4 * Copyright (C) 2014 Google, Inc.
   5 *
   6 * This software is licensed under the terms of the GNU General Public
   7 * License version 2, as published by the Free Software Foundation, and
   8 * may be copied, distributed, and modified under those terms.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 */
  15
  16#include <linux/backlight.h>
  17#include <linux/delay.h>
  18#include <linux/err.h>
  19#include <linux/gpio.h>
  20#include <linux/gpio/consumer.h>
  21#include <linux/i2c.h>
  22#include <linux/module.h>
  23#include <linux/of.h>
  24#include <linux/of_device.h>
  25#include <linux/pm.h>
  26#include <linux/regulator/consumer.h>
  27#include <drm/drm_atomic_helper.h>
  28#include <drm/drm_crtc.h>
  29#include <drm/drm_crtc_helper.h>
  30#include <drm/drm_of.h>
  31#include <drm/drm_panel.h>
  32#include <drm/drmP.h>
  33
  34/* Brightness scale on the Parade chip */
  35#define PS8622_MAX_BRIGHTNESS 0xff
  36
  37/* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
  38#define PS8622_POWER_RISE_T1_MIN_US 10
  39#define PS8622_POWER_RISE_T1_MAX_US 10000
  40#define PS8622_RST_HIGH_T2_MIN_US 3000
  41#define PS8622_RST_HIGH_T2_MAX_US 30000
  42#define PS8622_PWMO_END_T12_MS 200
  43#define PS8622_POWER_FALL_T16_MAX_US 10000
  44#define PS8622_POWER_OFF_T17_MS 500
  45
  46#if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
  47        (PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
  48#error "T2.min + T1.max must be less than T2.max + T1.min"
  49#endif
  50
  51struct ps8622_bridge {
  52        struct drm_connector connector;
  53        struct i2c_client *client;
  54        struct drm_bridge bridge;
  55        struct drm_panel *panel;
  56        struct regulator *v12;
  57        struct backlight_device *bl;
  58
  59        struct gpio_desc *gpio_slp;
  60        struct gpio_desc *gpio_rst;
  61
  62        u32 max_lane_count;
  63        u32 lane_count;
  64
  65        bool enabled;
  66};
  67
  68static inline struct ps8622_bridge *
  69                bridge_to_ps8622(struct drm_bridge *bridge)
  70{
  71        return container_of(bridge, struct ps8622_bridge, bridge);
  72}
  73
  74static inline struct ps8622_bridge *
  75                connector_to_ps8622(struct drm_connector *connector)
  76{
  77        return container_of(connector, struct ps8622_bridge, connector);
  78}
  79
  80static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
  81{
  82        int ret;
  83        struct i2c_adapter *adap = client->adapter;
  84        struct i2c_msg msg;
  85        u8 data[] = {reg, val};
  86
  87        msg.addr = client->addr + page;
  88        msg.flags = 0;
  89        msg.len = sizeof(data);
  90        msg.buf = data;
  91
  92        ret = i2c_transfer(adap, &msg, 1);
  93        if (ret != 1)
  94                pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
  95                        client->addr + page, reg, val, ret);
  96        return !(ret == 1);
  97}
  98
  99static int ps8622_send_config(struct ps8622_bridge *ps8622)
 100{
 101        struct i2c_client *cl = ps8622->client;
 102        int err = 0;
 103
 104        /* HPD low */
 105        err = ps8622_set(cl, 0x02, 0xa1, 0x01);
 106        if (err)
 107                goto error;
 108
 109        /* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
 110        err = ps8622_set(cl, 0x04, 0x14, 0x01);
 111        if (err)
 112                goto error;
 113
 114        /* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
 115        err = ps8622_set(cl, 0x04, 0xe3, 0x20);
 116        if (err)
 117                goto error;
 118
 119        /* [7] RCO SS enable */
 120        err = ps8622_set(cl, 0x04, 0xe2, 0x80);
 121        if (err)
 122                goto error;
 123
 124        /* RPHY Setting
 125         * [3:2] CDR tune wait cycle before measure for fine tune
 126         * b00: 1us b01: 0.5us b10:2us, b11: 4us
 127         */
 128        err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
 129        if (err)
 130                goto error;
 131
 132        /* [3] RFD always on */
 133        err = ps8622_set(cl, 0x04, 0x89, 0x08);
 134        if (err)
 135                goto error;
 136
 137        /* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
 138        err = ps8622_set(cl, 0x04, 0x71, 0x2d);
 139        if (err)
 140                goto error;
 141
 142        /* 2.7G CDR settings: NOF=40LSB for HBR CDR  setting */
 143        err = ps8622_set(cl, 0x04, 0x7d, 0x07);
 144        if (err)
 145                goto error;
 146
 147        /* [1:0] Fmin=+4bands */
 148        err = ps8622_set(cl, 0x04, 0x7b, 0x00);
 149        if (err)
 150                goto error;
 151
 152        /* [7:5] DCO_FTRNG=+-40% */
 153        err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
 154        if (err)
 155                goto error;
 156
 157        /* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
 158        err = ps8622_set(cl, 0x04, 0xc0, 0x12);
 159        if (err)
 160                goto error;
 161
 162        /* Gitune=-37% */
 163        err = ps8622_set(cl, 0x04, 0xc1, 0x92);
 164        if (err)
 165                goto error;
 166
 167        /* Fbstep=100% */
 168        err = ps8622_set(cl, 0x04, 0xc2, 0x1c);
 169        if (err)
 170                goto error;
 171
 172        /* [7] LOS signal disable */
 173        err = ps8622_set(cl, 0x04, 0x32, 0x80);
 174        if (err)
 175                goto error;
 176
 177        /* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */
 178        err = ps8622_set(cl, 0x04, 0x00, 0xb0);
 179        if (err)
 180                goto error;
 181
 182        /* [7:6] Right-bar GPIO output strength is 8mA */
 183        err = ps8622_set(cl, 0x04, 0x15, 0x40);
 184        if (err)
 185                goto error;
 186
 187        /* EQ Training State Machine Setting, RCO calibration start */
 188        err = ps8622_set(cl, 0x04, 0x54, 0x10);
 189        if (err)
 190                goto error;
 191
 192        /* Logic, needs more than 10 I2C command */
 193        /* [4:0] MAX_LANE_COUNT set to max supported lanes */
 194        err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count);
 195        if (err)
 196                goto error;
 197
 198        /* [4:0] LANE_COUNT_SET set to chosen lane count */
 199        err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count);
 200        if (err)
 201                goto error;
 202
 203        err = ps8622_set(cl, 0x00, 0x52, 0x20);
 204        if (err)
 205                goto error;
 206
 207        /* HPD CP toggle enable */
 208        err = ps8622_set(cl, 0x00, 0xf1, 0x03);
 209        if (err)
 210                goto error;
 211
 212        err = ps8622_set(cl, 0x00, 0x62, 0x41);
 213        if (err)
 214                goto error;
 215
 216        /* Counter number, add 1ms counter delay */
 217        err = ps8622_set(cl, 0x00, 0xf6, 0x01);
 218        if (err)
 219                goto error;
 220
 221        /* [6]PWM function control by DPCD0040f[7], default is PWM block */
 222        err = ps8622_set(cl, 0x00, 0x77, 0x06);
 223        if (err)
 224                goto error;
 225
 226        /* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */
 227        err = ps8622_set(cl, 0x00, 0x4c, 0x04);
 228        if (err)
 229                goto error;
 230
 231        /* DPCD00400='h00, Parade OUI ='h001cf8 */
 232        err = ps8622_set(cl, 0x01, 0xc0, 0x00);
 233        if (err)
 234                goto error;
 235
 236        /* DPCD00401='h1c */
 237        err = ps8622_set(cl, 0x01, 0xc1, 0x1c);
 238        if (err)
 239                goto error;
 240
 241        /* DPCD00402='hf8 */
 242        err = ps8622_set(cl, 0x01, 0xc2, 0xf8);
 243        if (err)
 244                goto error;
 245
 246        /* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */
 247        err = ps8622_set(cl, 0x01, 0xc3, 0x44);
 248        if (err)
 249                goto error;
 250
 251        /* DPCD404 */
 252        err = ps8622_set(cl, 0x01, 0xc4, 0x32);
 253        if (err)
 254                goto error;
 255
 256        /* DPCD405 */
 257        err = ps8622_set(cl, 0x01, 0xc5, 0x53);
 258        if (err)
 259                goto error;
 260
 261        /* DPCD406 */
 262        err = ps8622_set(cl, 0x01, 0xc6, 0x4c);
 263        if (err)
 264                goto error;
 265
 266        /* DPCD407 */
 267        err = ps8622_set(cl, 0x01, 0xc7, 0x56);
 268        if (err)
 269                goto error;
 270
 271        /* DPCD408 */
 272        err = ps8622_set(cl, 0x01, 0xc8, 0x35);
 273        if (err)
 274                goto error;
 275
 276        /* DPCD40A, Initial Code major revision '01' */
 277        err = ps8622_set(cl, 0x01, 0xca, 0x01);
 278        if (err)
 279                goto error;
 280
 281        /* DPCD40B, Initial Code minor revision '05' */
 282        err = ps8622_set(cl, 0x01, 0xcb, 0x05);
 283        if (err)
 284                goto error;
 285
 286
 287        if (ps8622->bl) {
 288                /* DPCD720, internal PWM */
 289                err = ps8622_set(cl, 0x01, 0xa5, 0xa0);
 290                if (err)
 291                        goto error;
 292
 293                /* FFh for 100% brightness, 0h for 0% brightness */
 294                err = ps8622_set(cl, 0x01, 0xa7,
 295                                ps8622->bl->props.brightness);
 296                if (err)
 297                        goto error;
 298        } else {
 299                /* DPCD720, external PWM */
 300                err = ps8622_set(cl, 0x01, 0xa5, 0x80);
 301                if (err)
 302                        goto error;
 303        }
 304
 305        /* Set LVDS output as 6bit-VESA mapping, single LVDS channel */
 306        err = ps8622_set(cl, 0x01, 0xcc, 0x13);
 307        if (err)
 308                goto error;
 309
 310        /* Enable SSC set by register */
 311        err = ps8622_set(cl, 0x02, 0xb1, 0x20);
 312        if (err)
 313                goto error;
 314
 315        /* Set SSC enabled and +/-1% central spreading */
 316        err = ps8622_set(cl, 0x04, 0x10, 0x16);
 317        if (err)
 318                goto error;
 319
 320        /* Logic end */
 321        /* MPU Clock source: LC => RCO */
 322        err = ps8622_set(cl, 0x04, 0x59, 0x60);
 323        if (err)
 324                goto error;
 325
 326        /* LC -> RCO */
 327        err = ps8622_set(cl, 0x04, 0x54, 0x14);
 328        if (err)
 329                goto error;
 330
 331        /* HPD high */
 332        err = ps8622_set(cl, 0x02, 0xa1, 0x91);
 333
 334error:
 335        return err ? -EIO : 0;
 336}
 337
 338static int ps8622_backlight_update(struct backlight_device *bl)
 339{
 340        struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
 341        int ret, brightness = bl->props.brightness;
 342
 343        if (bl->props.power != FB_BLANK_UNBLANK ||
 344            bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
 345                brightness = 0;
 346
 347        if (!ps8622->enabled)
 348                return -EINVAL;
 349
 350        ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);
 351
 352        return ret;
 353}
 354
 355static const struct backlight_ops ps8622_backlight_ops = {
 356        .update_status  = ps8622_backlight_update,
 357};
 358
 359static void ps8622_pre_enable(struct drm_bridge *bridge)
 360{
 361        struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
 362        int ret;
 363
 364        if (ps8622->enabled)
 365                return;
 366
 367        gpiod_set_value(ps8622->gpio_rst, 0);
 368
 369        if (ps8622->v12) {
 370                ret = regulator_enable(ps8622->v12);
 371                if (ret)
 372                        DRM_ERROR("fails to enable ps8622->v12");
 373        }
 374
 375        if (drm_panel_prepare(ps8622->panel)) {
 376                DRM_ERROR("failed to prepare panel\n");
 377                return;
 378        }
 379
 380        gpiod_set_value(ps8622->gpio_slp, 1);
 381
 382        /*
 383         * T1 is the range of time that it takes for the power to rise after we
 384         * enable the lcd/ps8622 fet. T2 is the range of time in which the
 385         * data sheet specifies we should deassert the reset pin.
 386         *
 387         * If it takes T1.max for the power to rise, we need to wait atleast
 388         * T2.min before deasserting the reset pin. If it takes T1.min for the
 389         * power to rise, we need to wait at most T2.max before deasserting the
 390         * reset pin.
 391         */
 392        usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
 393                     PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);
 394
 395        gpiod_set_value(ps8622->gpio_rst, 1);
 396
 397        /* wait 20ms after RST high */
 398        usleep_range(20000, 30000);
 399
 400        ret = ps8622_send_config(ps8622);
 401        if (ret) {
 402                DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
 403                return;
 404        }
 405
 406        ps8622->enabled = true;
 407}
 408
 409static void ps8622_enable(struct drm_bridge *bridge)
 410{
 411        struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
 412
 413        if (drm_panel_enable(ps8622->panel)) {
 414                DRM_ERROR("failed to enable panel\n");
 415                return;
 416        }
 417}
 418
 419static void ps8622_disable(struct drm_bridge *bridge)
 420{
 421        struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
 422
 423        if (drm_panel_disable(ps8622->panel)) {
 424                DRM_ERROR("failed to disable panel\n");
 425                return;
 426        }
 427        msleep(PS8622_PWMO_END_T12_MS);
 428}
 429
 430static void ps8622_post_disable(struct drm_bridge *bridge)
 431{
 432        struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
 433
 434        if (!ps8622->enabled)
 435                return;
 436
 437        ps8622->enabled = false;
 438
 439        /*
 440         * This doesn't matter if the regulators are turned off, but something
 441         * else might keep them on. In that case, we want to assert the slp gpio
 442         * to lower power.
 443         */
 444        gpiod_set_value(ps8622->gpio_slp, 0);
 445
 446        if (drm_panel_unprepare(ps8622->panel)) {
 447                DRM_ERROR("failed to unprepare panel\n");
 448                return;
 449        }
 450
 451        if (ps8622->v12)
 452                regulator_disable(ps8622->v12);
 453
 454        /*
 455         * Sleep for at least the amount of time that it takes the power rail to
 456         * fall to prevent asserting the rst gpio from doing anything.
 457         */
 458        usleep_range(PS8622_POWER_FALL_T16_MAX_US,
 459                     2 * PS8622_POWER_FALL_T16_MAX_US);
 460        gpiod_set_value(ps8622->gpio_rst, 0);
 461
 462        msleep(PS8622_POWER_OFF_T17_MS);
 463}
 464
 465static int ps8622_get_modes(struct drm_connector *connector)
 466{
 467        struct ps8622_bridge *ps8622;
 468
 469        ps8622 = connector_to_ps8622(connector);
 470
 471        return drm_panel_get_modes(ps8622->panel);
 472}
 473
 474static const struct drm_connector_helper_funcs ps8622_connector_helper_funcs = {
 475        .get_modes = ps8622_get_modes,
 476};
 477
 478static const struct drm_connector_funcs ps8622_connector_funcs = {
 479        .fill_modes = drm_helper_probe_single_connector_modes,
 480        .destroy = drm_connector_cleanup,
 481        .reset = drm_atomic_helper_connector_reset,
 482        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 483        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 484};
 485
 486static int ps8622_attach(struct drm_bridge *bridge)
 487{
 488        struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
 489        int ret;
 490
 491        if (!bridge->encoder) {
 492                DRM_ERROR("Parent encoder object not found");
 493                return -ENODEV;
 494        }
 495
 496        ps8622->connector.polled = DRM_CONNECTOR_POLL_HPD;
 497        ret = drm_connector_init(bridge->dev, &ps8622->connector,
 498                        &ps8622_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
 499        if (ret) {
 500                DRM_ERROR("Failed to initialize connector with drm\n");
 501                return ret;
 502        }
 503        drm_connector_helper_add(&ps8622->connector,
 504                                        &ps8622_connector_helper_funcs);
 505        drm_connector_register(&ps8622->connector);
 506        drm_connector_attach_encoder(&ps8622->connector,
 507                                                        bridge->encoder);
 508
 509        if (ps8622->panel)
 510                drm_panel_attach(ps8622->panel, &ps8622->connector);
 511
 512        drm_helper_hpd_irq_event(ps8622->connector.dev);
 513
 514        return ret;
 515}
 516
 517static const struct drm_bridge_funcs ps8622_bridge_funcs = {
 518        .pre_enable = ps8622_pre_enable,
 519        .enable = ps8622_enable,
 520        .disable = ps8622_disable,
 521        .post_disable = ps8622_post_disable,
 522        .attach = ps8622_attach,
 523};
 524
 525static const struct of_device_id ps8622_devices[] = {
 526        {.compatible = "parade,ps8622",},
 527        {.compatible = "parade,ps8625",},
 528        {}
 529};
 530MODULE_DEVICE_TABLE(of, ps8622_devices);
 531
 532static int ps8622_probe(struct i2c_client *client,
 533                                        const struct i2c_device_id *id)
 534{
 535        struct device *dev = &client->dev;
 536        struct ps8622_bridge *ps8622;
 537        int ret;
 538
 539        ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL);
 540        if (!ps8622)
 541                return -ENOMEM;
 542
 543        ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &ps8622->panel, NULL);
 544        if (ret)
 545                return ret;
 546
 547        ps8622->client = client;
 548
 549        ps8622->v12 = devm_regulator_get(dev, "vdd12");
 550        if (IS_ERR(ps8622->v12)) {
 551                dev_info(dev, "no 1.2v regulator found for PS8622\n");
 552                ps8622->v12 = NULL;
 553        }
 554
 555        ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH);
 556        if (IS_ERR(ps8622->gpio_slp)) {
 557                ret = PTR_ERR(ps8622->gpio_slp);
 558                dev_err(dev, "cannot get gpio_slp %d\n", ret);
 559                return ret;
 560        }
 561
 562        /*
 563         * Assert the reset pin high to avoid the bridge being
 564         * initialized prematurely
 565         */
 566        ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 567        if (IS_ERR(ps8622->gpio_rst)) {
 568                ret = PTR_ERR(ps8622->gpio_rst);
 569                dev_err(dev, "cannot get gpio_rst %d\n", ret);
 570                return ret;
 571        }
 572
 573        ps8622->max_lane_count = id->driver_data;
 574
 575        if (of_property_read_u32(dev->of_node, "lane-count",
 576                                                &ps8622->lane_count)) {
 577                ps8622->lane_count = ps8622->max_lane_count;
 578        } else if (ps8622->lane_count > ps8622->max_lane_count) {
 579                dev_info(dev, "lane-count property is too high,"
 580                                                "using max_lane_count\n");
 581                ps8622->lane_count = ps8622->max_lane_count;
 582        }
 583
 584        if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) {
 585                ps8622->bl = backlight_device_register("ps8622-backlight",
 586                                dev, ps8622, &ps8622_backlight_ops,
 587                                NULL);
 588                if (IS_ERR(ps8622->bl)) {
 589                        DRM_ERROR("failed to register backlight\n");
 590                        ret = PTR_ERR(ps8622->bl);
 591                        ps8622->bl = NULL;
 592                        return ret;
 593                }
 594                ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS;
 595                ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS;
 596        }
 597
 598        ps8622->bridge.funcs = &ps8622_bridge_funcs;
 599        ps8622->bridge.of_node = dev->of_node;
 600        drm_bridge_add(&ps8622->bridge);
 601
 602        i2c_set_clientdata(client, ps8622);
 603
 604        return 0;
 605}
 606
 607static int ps8622_remove(struct i2c_client *client)
 608{
 609        struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);
 610
 611        backlight_device_unregister(ps8622->bl);
 612        drm_bridge_remove(&ps8622->bridge);
 613
 614        return 0;
 615}
 616
 617static const struct i2c_device_id ps8622_i2c_table[] = {
 618        /* Device type, max_lane_count */
 619        {"ps8622", 1},
 620        {"ps8625", 2},
 621        {},
 622};
 623MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);
 624
 625static struct i2c_driver ps8622_driver = {
 626        .id_table       = ps8622_i2c_table,
 627        .probe          = ps8622_probe,
 628        .remove         = ps8622_remove,
 629        .driver         = {
 630                .name   = "ps8622",
 631                .of_match_table = ps8622_devices,
 632        },
 633};
 634module_i2c_driver(ps8622_driver);
 635
 636MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>");
 637MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
 638MODULE_LICENSE("GPL v2");
 639