linux/drivers/gpu/drm/bridge/ti-sn65dsi86.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2018, The Linux Foundation. All rights reserved.
   4 * datasheet: https://www.ti.com/lit/ds/symlink/sn65dsi86.pdf
   5 */
   6
   7#include <linux/bits.h>
   8#include <linux/clk.h>
   9#include <linux/debugfs.h>
  10#include <linux/gpio/consumer.h>
  11#include <linux/gpio/driver.h>
  12#include <linux/i2c.h>
  13#include <linux/iopoll.h>
  14#include <linux/module.h>
  15#include <linux/of_graph.h>
  16#include <linux/pm_runtime.h>
  17#include <linux/regmap.h>
  18#include <linux/regulator/consumer.h>
  19
  20#include <drm/drm_atomic.h>
  21#include <drm/drm_atomic_helper.h>
  22#include <drm/drm_bridge.h>
  23#include <drm/drm_dp_helper.h>
  24#include <drm/drm_mipi_dsi.h>
  25#include <drm/drm_of.h>
  26#include <drm/drm_panel.h>
  27#include <drm/drm_print.h>
  28#include <drm/drm_probe_helper.h>
  29
  30#define SN_DEVICE_REV_REG                       0x08
  31#define SN_DPPLL_SRC_REG                        0x0A
  32#define  DPPLL_CLK_SRC_DSICLK                   BIT(0)
  33#define  REFCLK_FREQ_MASK                       GENMASK(3, 1)
  34#define  REFCLK_FREQ(x)                         ((x) << 1)
  35#define  DPPLL_SRC_DP_PLL_LOCK                  BIT(7)
  36#define SN_PLL_ENABLE_REG                       0x0D
  37#define SN_DSI_LANES_REG                        0x10
  38#define  CHA_DSI_LANES_MASK                     GENMASK(4, 3)
  39#define  CHA_DSI_LANES(x)                       ((x) << 3)
  40#define SN_DSIA_CLK_FREQ_REG                    0x12
  41#define SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG       0x20
  42#define SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG    0x24
  43#define SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG        0x2C
  44#define SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG       0x2D
  45#define  CHA_HSYNC_POLARITY                     BIT(7)
  46#define SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG        0x30
  47#define SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG       0x31
  48#define  CHA_VSYNC_POLARITY                     BIT(7)
  49#define SN_CHA_HORIZONTAL_BACK_PORCH_REG        0x34
  50#define SN_CHA_VERTICAL_BACK_PORCH_REG          0x36
  51#define SN_CHA_HORIZONTAL_FRONT_PORCH_REG       0x38
  52#define SN_CHA_VERTICAL_FRONT_PORCH_REG         0x3A
  53#define SN_LN_ASSIGN_REG                        0x59
  54#define  LN_ASSIGN_WIDTH                        2
  55#define SN_ENH_FRAME_REG                        0x5A
  56#define  VSTREAM_ENABLE                         BIT(3)
  57#define  LN_POLRS_OFFSET                        4
  58#define  LN_POLRS_MASK                          0xf0
  59#define SN_DATA_FORMAT_REG                      0x5B
  60#define  BPP_18_RGB                             BIT(0)
  61#define SN_HPD_DISABLE_REG                      0x5C
  62#define  HPD_DISABLE                            BIT(0)
  63#define SN_GPIO_IO_REG                          0x5E
  64#define  SN_GPIO_INPUT_SHIFT                    4
  65#define  SN_GPIO_OUTPUT_SHIFT                   0
  66#define SN_GPIO_CTRL_REG                        0x5F
  67#define  SN_GPIO_MUX_INPUT                      0
  68#define  SN_GPIO_MUX_OUTPUT                     1
  69#define  SN_GPIO_MUX_SPECIAL                    2
  70#define  SN_GPIO_MUX_MASK                       0x3
  71#define SN_AUX_WDATA_REG(x)                     (0x64 + (x))
  72#define SN_AUX_ADDR_19_16_REG                   0x74
  73#define SN_AUX_ADDR_15_8_REG                    0x75
  74#define SN_AUX_ADDR_7_0_REG                     0x76
  75#define SN_AUX_LENGTH_REG                       0x77
  76#define SN_AUX_CMD_REG                          0x78
  77#define  AUX_CMD_SEND                           BIT(0)
  78#define  AUX_CMD_REQ(x)                         ((x) << 4)
  79#define SN_AUX_RDATA_REG(x)                     (0x79 + (x))
  80#define SN_SSC_CONFIG_REG                       0x93
  81#define  DP_NUM_LANES_MASK                      GENMASK(5, 4)
  82#define  DP_NUM_LANES(x)                        ((x) << 4)
  83#define SN_DATARATE_CONFIG_REG                  0x94
  84#define  DP_DATARATE_MASK                       GENMASK(7, 5)
  85#define  DP_DATARATE(x)                         ((x) << 5)
  86#define SN_ML_TX_MODE_REG                       0x96
  87#define  ML_TX_MAIN_LINK_OFF                    0
  88#define  ML_TX_NORMAL_MODE                      BIT(0)
  89#define SN_AUX_CMD_STATUS_REG                   0xF4
  90#define  AUX_IRQ_STATUS_AUX_RPLY_TOUT           BIT(3)
  91#define  AUX_IRQ_STATUS_AUX_SHORT               BIT(5)
  92#define  AUX_IRQ_STATUS_NAT_I2C_FAIL            BIT(6)
  93
  94#define MIN_DSI_CLK_FREQ_MHZ    40
  95
  96/* fudge factor required to account for 8b/10b encoding */
  97#define DP_CLK_FUDGE_NUM        10
  98#define DP_CLK_FUDGE_DEN        8
  99
 100/* Matches DP_AUX_MAX_PAYLOAD_BYTES (for now) */
 101#define SN_AUX_MAX_PAYLOAD_BYTES        16
 102
 103#define SN_REGULATOR_SUPPLY_NUM         4
 104
 105#define SN_MAX_DP_LANES                 4
 106#define SN_NUM_GPIOS                    4
 107#define SN_GPIO_PHYSICAL_OFFSET         1
 108
 109/**
 110 * struct ti_sn_bridge - Platform data for ti-sn65dsi86 driver.
 111 * @dev:          Pointer to our device.
 112 * @regmap:       Regmap for accessing i2c.
 113 * @aux:          Our aux channel.
 114 * @bridge:       Our bridge.
 115 * @connector:    Our connector.
 116 * @debugfs:      Used for managing our debugfs.
 117 * @host_node:    Remote DSI node.
 118 * @dsi:          Our MIPI DSI source.
 119 * @refclk:       Our reference clock.
 120 * @panel:        Our panel.
 121 * @enable_gpio:  The GPIO we toggle to enable the bridge.
 122 * @supplies:     Data for bulk enabling/disabling our regulators.
 123 * @dp_lanes:     Count of dp_lanes we're using.
 124 * @ln_assign:    Value to program to the LN_ASSIGN register.
 125 * @ln_polrs:     Value for the 4-bit LN_POLRS field of SN_ENH_FRAME_REG.
 126 *
 127 * @gchip:        If we expose our GPIOs, this is used.
 128 * @gchip_output: A cache of whether we've set GPIOs to output.  This
 129 *                serves double-duty of keeping track of the direction and
 130 *                also keeping track of whether we've incremented the
 131 *                pm_runtime reference count for this pin, which we do
 132 *                whenever a pin is configured as an output.  This is a
 133 *                bitmap so we can do atomic ops on it without an extra
 134 *                lock so concurrent users of our 4 GPIOs don't stomp on
 135 *                each other's read-modify-write.
 136 */
 137struct ti_sn_bridge {
 138        struct device                   *dev;
 139        struct regmap                   *regmap;
 140        struct drm_dp_aux               aux;
 141        struct drm_bridge               bridge;
 142        struct drm_connector            connector;
 143        struct dentry                   *debugfs;
 144        struct device_node              *host_node;
 145        struct mipi_dsi_device          *dsi;
 146        struct clk                      *refclk;
 147        struct drm_panel                *panel;
 148        struct gpio_desc                *enable_gpio;
 149        struct regulator_bulk_data      supplies[SN_REGULATOR_SUPPLY_NUM];
 150        int                             dp_lanes;
 151        u8                              ln_assign;
 152        u8                              ln_polrs;
 153
 154#if defined(CONFIG_OF_GPIO)
 155        struct gpio_chip                gchip;
 156        DECLARE_BITMAP(gchip_output, SN_NUM_GPIOS);
 157#endif
 158};
 159
 160static const struct regmap_range ti_sn_bridge_volatile_ranges[] = {
 161        { .range_min = 0, .range_max = 0xFF },
 162};
 163
 164static const struct regmap_access_table ti_sn_bridge_volatile_table = {
 165        .yes_ranges = ti_sn_bridge_volatile_ranges,
 166        .n_yes_ranges = ARRAY_SIZE(ti_sn_bridge_volatile_ranges),
 167};
 168
 169static const struct regmap_config ti_sn_bridge_regmap_config = {
 170        .reg_bits = 8,
 171        .val_bits = 8,
 172        .volatile_table = &ti_sn_bridge_volatile_table,
 173        .cache_type = REGCACHE_NONE,
 174};
 175
 176static void ti_sn_bridge_write_u16(struct ti_sn_bridge *pdata,
 177                                   unsigned int reg, u16 val)
 178{
 179        regmap_write(pdata->regmap, reg, val & 0xFF);
 180        regmap_write(pdata->regmap, reg + 1, val >> 8);
 181}
 182
 183static int __maybe_unused ti_sn_bridge_resume(struct device *dev)
 184{
 185        struct ti_sn_bridge *pdata = dev_get_drvdata(dev);
 186        int ret;
 187
 188        ret = regulator_bulk_enable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
 189        if (ret) {
 190                DRM_ERROR("failed to enable supplies %d\n", ret);
 191                return ret;
 192        }
 193
 194        gpiod_set_value(pdata->enable_gpio, 1);
 195
 196        return ret;
 197}
 198
 199static int __maybe_unused ti_sn_bridge_suspend(struct device *dev)
 200{
 201        struct ti_sn_bridge *pdata = dev_get_drvdata(dev);
 202        int ret;
 203
 204        gpiod_set_value(pdata->enable_gpio, 0);
 205
 206        ret = regulator_bulk_disable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
 207        if (ret)
 208                DRM_ERROR("failed to disable supplies %d\n", ret);
 209
 210        return ret;
 211}
 212
 213static const struct dev_pm_ops ti_sn_bridge_pm_ops = {
 214        SET_RUNTIME_PM_OPS(ti_sn_bridge_suspend, ti_sn_bridge_resume, NULL)
 215        SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 216                                pm_runtime_force_resume)
 217};
 218
 219static int status_show(struct seq_file *s, void *data)
 220{
 221        struct ti_sn_bridge *pdata = s->private;
 222        unsigned int reg, val;
 223
 224        seq_puts(s, "STATUS REGISTERS:\n");
 225
 226        pm_runtime_get_sync(pdata->dev);
 227
 228        /* IRQ Status Registers, see Table 31 in datasheet */
 229        for (reg = 0xf0; reg <= 0xf8; reg++) {
 230                regmap_read(pdata->regmap, reg, &val);
 231                seq_printf(s, "[0x%02x] = 0x%08x\n", reg, val);
 232        }
 233
 234        pm_runtime_put(pdata->dev);
 235
 236        return 0;
 237}
 238
 239DEFINE_SHOW_ATTRIBUTE(status);
 240
 241static void ti_sn_debugfs_init(struct ti_sn_bridge *pdata)
 242{
 243        pdata->debugfs = debugfs_create_dir(dev_name(pdata->dev), NULL);
 244
 245        debugfs_create_file("status", 0600, pdata->debugfs, pdata,
 246                        &status_fops);
 247}
 248
 249static void ti_sn_debugfs_remove(struct ti_sn_bridge *pdata)
 250{
 251        debugfs_remove_recursive(pdata->debugfs);
 252        pdata->debugfs = NULL;
 253}
 254
 255/* Connector funcs */
 256static struct ti_sn_bridge *
 257connector_to_ti_sn_bridge(struct drm_connector *connector)
 258{
 259        return container_of(connector, struct ti_sn_bridge, connector);
 260}
 261
 262static int ti_sn_bridge_connector_get_modes(struct drm_connector *connector)
 263{
 264        struct ti_sn_bridge *pdata = connector_to_ti_sn_bridge(connector);
 265
 266        return drm_panel_get_modes(pdata->panel, connector);
 267}
 268
 269static enum drm_mode_status
 270ti_sn_bridge_connector_mode_valid(struct drm_connector *connector,
 271                                  struct drm_display_mode *mode)
 272{
 273        /* maximum supported resolution is 4K at 60 fps */
 274        if (mode->clock > 594000)
 275                return MODE_CLOCK_HIGH;
 276
 277        return MODE_OK;
 278}
 279
 280static struct drm_connector_helper_funcs ti_sn_bridge_connector_helper_funcs = {
 281        .get_modes = ti_sn_bridge_connector_get_modes,
 282        .mode_valid = ti_sn_bridge_connector_mode_valid,
 283};
 284
 285static enum drm_connector_status
 286ti_sn_bridge_connector_detect(struct drm_connector *connector, bool force)
 287{
 288        /**
 289         * TODO: Currently if drm_panel is present, then always
 290         * return the status as connected. Need to add support to detect
 291         * device state for hot pluggable scenarios.
 292         */
 293        return connector_status_connected;
 294}
 295
 296static const struct drm_connector_funcs ti_sn_bridge_connector_funcs = {
 297        .fill_modes = drm_helper_probe_single_connector_modes,
 298        .detect = ti_sn_bridge_connector_detect,
 299        .destroy = drm_connector_cleanup,
 300        .reset = drm_atomic_helper_connector_reset,
 301        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 302        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 303};
 304
 305static struct ti_sn_bridge *bridge_to_ti_sn_bridge(struct drm_bridge *bridge)
 306{
 307        return container_of(bridge, struct ti_sn_bridge, bridge);
 308}
 309
 310static int ti_sn_bridge_parse_regulators(struct ti_sn_bridge *pdata)
 311{
 312        unsigned int i;
 313        const char * const ti_sn_bridge_supply_names[] = {
 314                "vcca", "vcc", "vccio", "vpll",
 315        };
 316
 317        for (i = 0; i < SN_REGULATOR_SUPPLY_NUM; i++)
 318                pdata->supplies[i].supply = ti_sn_bridge_supply_names[i];
 319
 320        return devm_regulator_bulk_get(pdata->dev, SN_REGULATOR_SUPPLY_NUM,
 321                                       pdata->supplies);
 322}
 323
 324static int ti_sn_bridge_attach(struct drm_bridge *bridge,
 325                               enum drm_bridge_attach_flags flags)
 326{
 327        int ret, val;
 328        struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
 329        struct mipi_dsi_host *host;
 330        struct mipi_dsi_device *dsi;
 331        const struct mipi_dsi_device_info info = { .type = "ti_sn_bridge",
 332                                                   .channel = 0,
 333                                                   .node = NULL,
 334                                                 };
 335
 336        if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
 337                DRM_ERROR("Fix bridge driver to make connector optional!");
 338                return -EINVAL;
 339        }
 340
 341        ret = drm_connector_init(bridge->dev, &pdata->connector,
 342                                 &ti_sn_bridge_connector_funcs,
 343                                 DRM_MODE_CONNECTOR_eDP);
 344        if (ret) {
 345                DRM_ERROR("Failed to initialize connector with drm\n");
 346                return ret;
 347        }
 348
 349        drm_connector_helper_add(&pdata->connector,
 350                                 &ti_sn_bridge_connector_helper_funcs);
 351        drm_connector_attach_encoder(&pdata->connector, bridge->encoder);
 352
 353        /*
 354         * TODO: ideally finding host resource and dsi dev registration needs
 355         * to be done in bridge probe. But some existing DSI host drivers will
 356         * wait for any of the drm_bridge/drm_panel to get added to the global
 357         * bridge/panel list, before completing their probe. So if we do the
 358         * dsi dev registration part in bridge probe, before populating in
 359         * the global bridge list, then it will cause deadlock as dsi host probe
 360         * will never complete, neither our bridge probe. So keeping it here
 361         * will satisfy most of the existing host drivers. Once the host driver
 362         * is fixed we can move the below code to bridge probe safely.
 363         */
 364        host = of_find_mipi_dsi_host_by_node(pdata->host_node);
 365        if (!host) {
 366                DRM_ERROR("failed to find dsi host\n");
 367                ret = -ENODEV;
 368                goto err_dsi_host;
 369        }
 370
 371        dsi = mipi_dsi_device_register_full(host, &info);
 372        if (IS_ERR(dsi)) {
 373                DRM_ERROR("failed to create dsi device\n");
 374                ret = PTR_ERR(dsi);
 375                goto err_dsi_host;
 376        }
 377
 378        /* TODO: setting to 4 MIPI lanes always for now */
 379        dsi->lanes = 4;
 380        dsi->format = MIPI_DSI_FMT_RGB888;
 381        dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
 382
 383        /* check if continuous dsi clock is required or not */
 384        pm_runtime_get_sync(pdata->dev);
 385        regmap_read(pdata->regmap, SN_DPPLL_SRC_REG, &val);
 386        pm_runtime_put(pdata->dev);
 387        if (!(val & DPPLL_CLK_SRC_DSICLK))
 388                dsi->mode_flags |= MIPI_DSI_CLOCK_NON_CONTINUOUS;
 389
 390        ret = mipi_dsi_attach(dsi);
 391        if (ret < 0) {
 392                DRM_ERROR("failed to attach dsi to host\n");
 393                goto err_dsi_attach;
 394        }
 395        pdata->dsi = dsi;
 396
 397        return 0;
 398
 399err_dsi_attach:
 400        mipi_dsi_device_unregister(dsi);
 401err_dsi_host:
 402        drm_connector_cleanup(&pdata->connector);
 403        return ret;
 404}
 405
 406static void ti_sn_bridge_disable(struct drm_bridge *bridge)
 407{
 408        struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
 409
 410        drm_panel_disable(pdata->panel);
 411
 412        /* disable video stream */
 413        regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE, 0);
 414        /* semi auto link training mode OFF */
 415        regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0);
 416        /* disable DP PLL */
 417        regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
 418
 419        drm_panel_unprepare(pdata->panel);
 420}
 421
 422static u32 ti_sn_bridge_get_dsi_freq(struct ti_sn_bridge *pdata)
 423{
 424        u32 bit_rate_khz, clk_freq_khz;
 425        struct drm_display_mode *mode =
 426                &pdata->bridge.encoder->crtc->state->adjusted_mode;
 427
 428        bit_rate_khz = mode->clock *
 429                        mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
 430        clk_freq_khz = bit_rate_khz / (pdata->dsi->lanes * 2);
 431
 432        return clk_freq_khz;
 433}
 434
 435/* clk frequencies supported by bridge in Hz in case derived from REFCLK pin */
 436static const u32 ti_sn_bridge_refclk_lut[] = {
 437        12000000,
 438        19200000,
 439        26000000,
 440        27000000,
 441        38400000,
 442};
 443
 444/* clk frequencies supported by bridge in Hz in case derived from DACP/N pin */
 445static const u32 ti_sn_bridge_dsiclk_lut[] = {
 446        468000000,
 447        384000000,
 448        416000000,
 449        486000000,
 450        460800000,
 451};
 452
 453static void ti_sn_bridge_set_refclk_freq(struct ti_sn_bridge *pdata)
 454{
 455        int i;
 456        u32 refclk_rate;
 457        const u32 *refclk_lut;
 458        size_t refclk_lut_size;
 459
 460        if (pdata->refclk) {
 461                refclk_rate = clk_get_rate(pdata->refclk);
 462                refclk_lut = ti_sn_bridge_refclk_lut;
 463                refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_refclk_lut);
 464                clk_prepare_enable(pdata->refclk);
 465        } else {
 466                refclk_rate = ti_sn_bridge_get_dsi_freq(pdata) * 1000;
 467                refclk_lut = ti_sn_bridge_dsiclk_lut;
 468                refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_dsiclk_lut);
 469        }
 470
 471        /* for i equals to refclk_lut_size means default frequency */
 472        for (i = 0; i < refclk_lut_size; i++)
 473                if (refclk_lut[i] == refclk_rate)
 474                        break;
 475
 476        regmap_update_bits(pdata->regmap, SN_DPPLL_SRC_REG, REFCLK_FREQ_MASK,
 477                           REFCLK_FREQ(i));
 478}
 479
 480static void ti_sn_bridge_set_dsi_rate(struct ti_sn_bridge *pdata)
 481{
 482        unsigned int bit_rate_mhz, clk_freq_mhz;
 483        unsigned int val;
 484        struct drm_display_mode *mode =
 485                &pdata->bridge.encoder->crtc->state->adjusted_mode;
 486
 487        /* set DSIA clk frequency */
 488        bit_rate_mhz = (mode->clock / 1000) *
 489                        mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
 490        clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
 491
 492        /* for each increment in val, frequency increases by 5MHz */
 493        val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
 494                (((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);
 495        regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
 496}
 497
 498static unsigned int ti_sn_bridge_get_bpp(struct ti_sn_bridge *pdata)
 499{
 500        if (pdata->connector.display_info.bpc <= 6)
 501                return 18;
 502        else
 503                return 24;
 504}
 505
 506/*
 507 * LUT index corresponds to register value and
 508 * LUT values corresponds to dp data rate supported
 509 * by the bridge in Mbps unit.
 510 */
 511static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
 512        0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
 513};
 514
 515static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn_bridge *pdata)
 516{
 517        unsigned int bit_rate_khz, dp_rate_mhz;
 518        unsigned int i;
 519        struct drm_display_mode *mode =
 520                &pdata->bridge.encoder->crtc->state->adjusted_mode;
 521
 522        /* Calculate minimum bit rate based on our pixel clock. */
 523        bit_rate_khz = mode->clock * ti_sn_bridge_get_bpp(pdata);
 524
 525        /* Calculate minimum DP data rate, taking 80% as per DP spec */
 526        dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM,
 527                                   1000 * pdata->dp_lanes * DP_CLK_FUDGE_DEN);
 528
 529        for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++)
 530                if (ti_sn_bridge_dp_rate_lut[i] >= dp_rate_mhz)
 531                        break;
 532
 533        return i;
 534}
 535
 536static void ti_sn_bridge_read_valid_rates(struct ti_sn_bridge *pdata,
 537                                          bool rate_valid[])
 538{
 539        unsigned int rate_per_200khz;
 540        unsigned int rate_mhz;
 541        u8 dpcd_val;
 542        int ret;
 543        int i, j;
 544
 545        ret = drm_dp_dpcd_readb(&pdata->aux, DP_EDP_DPCD_REV, &dpcd_val);
 546        if (ret != 1) {
 547                DRM_DEV_ERROR(pdata->dev,
 548                              "Can't read eDP rev (%d), assuming 1.1\n", ret);
 549                dpcd_val = DP_EDP_11;
 550        }
 551
 552        if (dpcd_val >= DP_EDP_14) {
 553                /* eDP 1.4 devices must provide a custom table */
 554                __le16 sink_rates[DP_MAX_SUPPORTED_RATES];
 555
 556                ret = drm_dp_dpcd_read(&pdata->aux, DP_SUPPORTED_LINK_RATES,
 557                                       sink_rates, sizeof(sink_rates));
 558
 559                if (ret != sizeof(sink_rates)) {
 560                        DRM_DEV_ERROR(pdata->dev,
 561                                "Can't read supported rate table (%d)\n", ret);
 562
 563                        /* By zeroing we'll fall back to DP_MAX_LINK_RATE. */
 564                        memset(sink_rates, 0, sizeof(sink_rates));
 565                }
 566
 567                for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
 568                        rate_per_200khz = le16_to_cpu(sink_rates[i]);
 569
 570                        if (!rate_per_200khz)
 571                                break;
 572
 573                        rate_mhz = rate_per_200khz * 200 / 1000;
 574                        for (j = 0;
 575                             j < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
 576                             j++) {
 577                                if (ti_sn_bridge_dp_rate_lut[j] == rate_mhz)
 578                                        rate_valid[j] = true;
 579                        }
 580                }
 581
 582                for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); i++) {
 583                        if (rate_valid[i])
 584                                return;
 585                }
 586                DRM_DEV_ERROR(pdata->dev,
 587                              "No matching eDP rates in table; falling back\n");
 588        }
 589
 590        /* On older versions best we can do is use DP_MAX_LINK_RATE */
 591        ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &dpcd_val);
 592        if (ret != 1) {
 593                DRM_DEV_ERROR(pdata->dev,
 594                              "Can't read max rate (%d); assuming 5.4 GHz\n",
 595                              ret);
 596                dpcd_val = DP_LINK_BW_5_4;
 597        }
 598
 599        switch (dpcd_val) {
 600        default:
 601                DRM_DEV_ERROR(pdata->dev,
 602                              "Unexpected max rate (%#x); assuming 5.4 GHz\n",
 603                              (int)dpcd_val);
 604                fallthrough;
 605        case DP_LINK_BW_5_4:
 606                rate_valid[7] = 1;
 607                fallthrough;
 608        case DP_LINK_BW_2_7:
 609                rate_valid[4] = 1;
 610                fallthrough;
 611        case DP_LINK_BW_1_62:
 612                rate_valid[1] = 1;
 613                break;
 614        }
 615}
 616
 617static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata)
 618{
 619        struct drm_display_mode *mode =
 620                &pdata->bridge.encoder->crtc->state->adjusted_mode;
 621        u8 hsync_polarity = 0, vsync_polarity = 0;
 622
 623        if (mode->flags & DRM_MODE_FLAG_PHSYNC)
 624                hsync_polarity = CHA_HSYNC_POLARITY;
 625        if (mode->flags & DRM_MODE_FLAG_PVSYNC)
 626                vsync_polarity = CHA_VSYNC_POLARITY;
 627
 628        ti_sn_bridge_write_u16(pdata, SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG,
 629                               mode->hdisplay);
 630        ti_sn_bridge_write_u16(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG,
 631                               mode->vdisplay);
 632        regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG,
 633                     (mode->hsync_end - mode->hsync_start) & 0xFF);
 634        regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG,
 635                     (((mode->hsync_end - mode->hsync_start) >> 8) & 0x7F) |
 636                     hsync_polarity);
 637        regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG,
 638                     (mode->vsync_end - mode->vsync_start) & 0xFF);
 639        regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG,
 640                     (((mode->vsync_end - mode->vsync_start) >> 8) & 0x7F) |
 641                     vsync_polarity);
 642
 643        regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_BACK_PORCH_REG,
 644                     (mode->htotal - mode->hsync_end) & 0xFF);
 645        regmap_write(pdata->regmap, SN_CHA_VERTICAL_BACK_PORCH_REG,
 646                     (mode->vtotal - mode->vsync_end) & 0xFF);
 647
 648        regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_FRONT_PORCH_REG,
 649                     (mode->hsync_start - mode->hdisplay) & 0xFF);
 650        regmap_write(pdata->regmap, SN_CHA_VERTICAL_FRONT_PORCH_REG,
 651                     (mode->vsync_start - mode->vdisplay) & 0xFF);
 652
 653        usleep_range(10000, 10500); /* 10ms delay recommended by spec */
 654}
 655
 656static unsigned int ti_sn_get_max_lanes(struct ti_sn_bridge *pdata)
 657{
 658        u8 data;
 659        int ret;
 660
 661        ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LANE_COUNT, &data);
 662        if (ret != 1) {
 663                DRM_DEV_ERROR(pdata->dev,
 664                              "Can't read lane count (%d); assuming 4\n", ret);
 665                return 4;
 666        }
 667
 668        return data & DP_LANE_COUNT_MASK;
 669}
 670
 671static int ti_sn_link_training(struct ti_sn_bridge *pdata, int dp_rate_idx,
 672                               const char **last_err_str)
 673{
 674        unsigned int val;
 675        int ret;
 676
 677        /* set dp clk frequency value */
 678        regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
 679                           DP_DATARATE_MASK, DP_DATARATE(dp_rate_idx));
 680
 681        /* enable DP PLL */
 682        regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
 683
 684        ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
 685                                       val & DPPLL_SRC_DP_PLL_LOCK, 1000,
 686                                       50 * 1000);
 687        if (ret) {
 688                *last_err_str = "DP_PLL_LOCK polling failed";
 689                goto exit;
 690        }
 691
 692        /* Semi auto link training mode */
 693        regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
 694        ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
 695                                       val == ML_TX_MAIN_LINK_OFF ||
 696                                       val == ML_TX_NORMAL_MODE, 1000,
 697                                       500 * 1000);
 698        if (ret) {
 699                *last_err_str = "Training complete polling failed";
 700        } else if (val == ML_TX_MAIN_LINK_OFF) {
 701                *last_err_str = "Link training failed, link is off";
 702                ret = -EIO;
 703        }
 704
 705exit:
 706        /* Disable the PLL if we failed */
 707        if (ret)
 708                regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
 709
 710        return ret;
 711}
 712
 713static void ti_sn_bridge_enable(struct drm_bridge *bridge)
 714{
 715        struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
 716        bool rate_valid[ARRAY_SIZE(ti_sn_bridge_dp_rate_lut)] = { };
 717        const char *last_err_str = "No supported DP rate";
 718        int dp_rate_idx;
 719        unsigned int val;
 720        int ret = -EINVAL;
 721        int max_dp_lanes;
 722
 723        max_dp_lanes = ti_sn_get_max_lanes(pdata);
 724        pdata->dp_lanes = min(pdata->dp_lanes, max_dp_lanes);
 725
 726        /* DSI_A lane config */
 727        val = CHA_DSI_LANES(SN_MAX_DP_LANES - pdata->dsi->lanes);
 728        regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
 729                           CHA_DSI_LANES_MASK, val);
 730
 731        regmap_write(pdata->regmap, SN_LN_ASSIGN_REG, pdata->ln_assign);
 732        regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, LN_POLRS_MASK,
 733                           pdata->ln_polrs << LN_POLRS_OFFSET);
 734
 735        /* set dsi clk frequency value */
 736        ti_sn_bridge_set_dsi_rate(pdata);
 737
 738        /**
 739         * The SN65DSI86 only supports ASSR Display Authentication method and
 740         * this method is enabled by default. An eDP panel must support this
 741         * authentication method. We need to enable this method in the eDP panel
 742         * at DisplayPort address 0x0010A prior to link training.
 743         */
 744        drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
 745                           DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
 746
 747        /* Set the DP output format (18 bpp or 24 bpp) */
 748        val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
 749        regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
 750
 751        /* DP lane config */
 752        val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
 753        regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
 754                           val);
 755
 756        ti_sn_bridge_read_valid_rates(pdata, rate_valid);
 757
 758        /* Train until we run out of rates */
 759        for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata);
 760             dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
 761             dp_rate_idx++) {
 762                if (!rate_valid[dp_rate_idx])
 763                        continue;
 764
 765                ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str);
 766                if (!ret)
 767                        break;
 768        }
 769        if (ret) {
 770                DRM_DEV_ERROR(pdata->dev, "%s (%d)\n", last_err_str, ret);
 771                return;
 772        }
 773
 774        /* config video parameters */
 775        ti_sn_bridge_set_video_timings(pdata);
 776
 777        /* enable video stream */
 778        regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE,
 779                           VSTREAM_ENABLE);
 780
 781        drm_panel_enable(pdata->panel);
 782}
 783
 784static void ti_sn_bridge_pre_enable(struct drm_bridge *bridge)
 785{
 786        struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
 787
 788        pm_runtime_get_sync(pdata->dev);
 789
 790        /* configure bridge ref_clk */
 791        ti_sn_bridge_set_refclk_freq(pdata);
 792
 793        /*
 794         * HPD on this bridge chip is a bit useless.  This is an eDP bridge
 795         * so the HPD is an internal signal that's only there to signal that
 796         * the panel is done powering up.  ...but the bridge chip debounces
 797         * this signal by between 100 ms and 400 ms (depending on process,
 798         * voltage, and temperate--I measured it at about 200 ms).  One
 799         * particular panel asserted HPD 84 ms after it was powered on meaning
 800         * that we saw HPD 284 ms after power on.  ...but the same panel said
 801         * that instead of looking at HPD you could just hardcode a delay of
 802         * 200 ms.  We'll assume that the panel driver will have the hardcoded
 803         * delay in its prepare and always disable HPD.
 804         *
 805         * If HPD somehow makes sense on some future panel we'll have to
 806         * change this to be conditional on someone specifying that HPD should
 807         * be used.
 808         */
 809        regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE,
 810                           HPD_DISABLE);
 811
 812        drm_panel_prepare(pdata->panel);
 813}
 814
 815static void ti_sn_bridge_post_disable(struct drm_bridge *bridge)
 816{
 817        struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
 818
 819        if (pdata->refclk)
 820                clk_disable_unprepare(pdata->refclk);
 821
 822        pm_runtime_put_sync(pdata->dev);
 823}
 824
 825static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
 826        .attach = ti_sn_bridge_attach,
 827        .pre_enable = ti_sn_bridge_pre_enable,
 828        .enable = ti_sn_bridge_enable,
 829        .disable = ti_sn_bridge_disable,
 830        .post_disable = ti_sn_bridge_post_disable,
 831};
 832
 833static struct ti_sn_bridge *aux_to_ti_sn_bridge(struct drm_dp_aux *aux)
 834{
 835        return container_of(aux, struct ti_sn_bridge, aux);
 836}
 837
 838static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux,
 839                                  struct drm_dp_aux_msg *msg)
 840{
 841        struct ti_sn_bridge *pdata = aux_to_ti_sn_bridge(aux);
 842        u32 request = msg->request & ~DP_AUX_I2C_MOT;
 843        u32 request_val = AUX_CMD_REQ(msg->request);
 844        u8 *buf = (u8 *)msg->buffer;
 845        unsigned int val;
 846        int ret, i;
 847
 848        if (msg->size > SN_AUX_MAX_PAYLOAD_BYTES)
 849                return -EINVAL;
 850
 851        switch (request) {
 852        case DP_AUX_NATIVE_WRITE:
 853        case DP_AUX_I2C_WRITE:
 854        case DP_AUX_NATIVE_READ:
 855        case DP_AUX_I2C_READ:
 856                regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val);
 857                break;
 858        default:
 859                return -EINVAL;
 860        }
 861
 862        regmap_write(pdata->regmap, SN_AUX_ADDR_19_16_REG,
 863                     (msg->address >> 16) & 0xF);
 864        regmap_write(pdata->regmap, SN_AUX_ADDR_15_8_REG,
 865                     (msg->address >> 8) & 0xFF);
 866        regmap_write(pdata->regmap, SN_AUX_ADDR_7_0_REG, msg->address & 0xFF);
 867
 868        regmap_write(pdata->regmap, SN_AUX_LENGTH_REG, msg->size);
 869
 870        if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE) {
 871                for (i = 0; i < msg->size; i++)
 872                        regmap_write(pdata->regmap, SN_AUX_WDATA_REG(i),
 873                                     buf[i]);
 874        }
 875
 876        /* Clear old status bits before start so we don't get confused */
 877        regmap_write(pdata->regmap, SN_AUX_CMD_STATUS_REG,
 878                     AUX_IRQ_STATUS_NAT_I2C_FAIL |
 879                     AUX_IRQ_STATUS_AUX_RPLY_TOUT |
 880                     AUX_IRQ_STATUS_AUX_SHORT);
 881
 882        regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val | AUX_CMD_SEND);
 883
 884        ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val,
 885                                       !(val & AUX_CMD_SEND), 200,
 886                                       50 * 1000);
 887        if (ret)
 888                return ret;
 889
 890        ret = regmap_read(pdata->regmap, SN_AUX_CMD_STATUS_REG, &val);
 891        if (ret)
 892                return ret;
 893        else if ((val & AUX_IRQ_STATUS_NAT_I2C_FAIL)
 894                 || (val & AUX_IRQ_STATUS_AUX_RPLY_TOUT)
 895                 || (val & AUX_IRQ_STATUS_AUX_SHORT))
 896                return -ENXIO;
 897
 898        if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE)
 899                return msg->size;
 900
 901        for (i = 0; i < msg->size; i++) {
 902                unsigned int val;
 903                ret = regmap_read(pdata->regmap, SN_AUX_RDATA_REG(i),
 904                                  &val);
 905                if (ret)
 906                        return ret;
 907
 908                WARN_ON(val & ~0xFF);
 909                buf[i] = (u8)(val & 0xFF);
 910        }
 911
 912        return msg->size;
 913}
 914
 915static int ti_sn_bridge_parse_dsi_host(struct ti_sn_bridge *pdata)
 916{
 917        struct device_node *np = pdata->dev->of_node;
 918
 919        pdata->host_node = of_graph_get_remote_node(np, 0, 0);
 920
 921        if (!pdata->host_node) {
 922                DRM_ERROR("remote dsi host node not found\n");
 923                return -ENODEV;
 924        }
 925
 926        return 0;
 927}
 928
 929#if defined(CONFIG_OF_GPIO)
 930
 931static int tn_sn_bridge_of_xlate(struct gpio_chip *chip,
 932                                 const struct of_phandle_args *gpiospec,
 933                                 u32 *flags)
 934{
 935        if (WARN_ON(gpiospec->args_count < chip->of_gpio_n_cells))
 936                return -EINVAL;
 937
 938        if (gpiospec->args[0] > chip->ngpio || gpiospec->args[0] < 1)
 939                return -EINVAL;
 940
 941        if (flags)
 942                *flags = gpiospec->args[1];
 943
 944        return gpiospec->args[0] - SN_GPIO_PHYSICAL_OFFSET;
 945}
 946
 947static int ti_sn_bridge_gpio_get_direction(struct gpio_chip *chip,
 948                                           unsigned int offset)
 949{
 950        struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
 951
 952        /*
 953         * We already have to keep track of the direction because we use
 954         * that to figure out whether we've powered the device.  We can
 955         * just return that rather than (maybe) powering up the device
 956         * to ask its direction.
 957         */
 958        return test_bit(offset, pdata->gchip_output) ?
 959                GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
 960}
 961
 962static int ti_sn_bridge_gpio_get(struct gpio_chip *chip, unsigned int offset)
 963{
 964        struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
 965        unsigned int val;
 966        int ret;
 967
 968        /*
 969         * When the pin is an input we don't forcibly keep the bridge
 970         * powered--we just power it on to read the pin.  NOTE: part of
 971         * the reason this works is that the bridge defaults (when
 972         * powered back on) to all 4 GPIOs being configured as GPIO input.
 973         * Also note that if something else is keeping the chip powered the
 974         * pm_runtime functions are lightweight increments of a refcount.
 975         */
 976        pm_runtime_get_sync(pdata->dev);
 977        ret = regmap_read(pdata->regmap, SN_GPIO_IO_REG, &val);
 978        pm_runtime_put(pdata->dev);
 979
 980        if (ret)
 981                return ret;
 982
 983        return !!(val & BIT(SN_GPIO_INPUT_SHIFT + offset));
 984}
 985
 986static void ti_sn_bridge_gpio_set(struct gpio_chip *chip, unsigned int offset,
 987                                  int val)
 988{
 989        struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
 990        int ret;
 991
 992        if (!test_bit(offset, pdata->gchip_output)) {
 993                dev_err(pdata->dev, "Ignoring GPIO set while input\n");
 994                return;
 995        }
 996
 997        val &= 1;
 998        ret = regmap_update_bits(pdata->regmap, SN_GPIO_IO_REG,
 999                                 BIT(SN_GPIO_OUTPUT_SHIFT + offset),
1000                                 val << (SN_GPIO_OUTPUT_SHIFT + offset));
1001        if (ret)
1002                dev_warn(pdata->dev,
1003                         "Failed to set bridge GPIO %u: %d\n", offset, ret);
1004}
1005
1006static int ti_sn_bridge_gpio_direction_input(struct gpio_chip *chip,
1007                                             unsigned int offset)
1008{
1009        struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
1010        int shift = offset * 2;
1011        int ret;
1012
1013        if (!test_and_clear_bit(offset, pdata->gchip_output))
1014                return 0;
1015
1016        ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1017                                 SN_GPIO_MUX_MASK << shift,
1018                                 SN_GPIO_MUX_INPUT << shift);
1019        if (ret) {
1020                set_bit(offset, pdata->gchip_output);
1021                return ret;
1022        }
1023
1024        /*
1025         * NOTE: if nobody else is powering the device this may fully power
1026         * it off and when it comes back it will have lost all state, but
1027         * that's OK because the default is input and we're now an input.
1028         */
1029        pm_runtime_put(pdata->dev);
1030
1031        return 0;
1032}
1033
1034static int ti_sn_bridge_gpio_direction_output(struct gpio_chip *chip,
1035                                              unsigned int offset, int val)
1036{
1037        struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
1038        int shift = offset * 2;
1039        int ret;
1040
1041        if (test_and_set_bit(offset, pdata->gchip_output))
1042                return 0;
1043
1044        pm_runtime_get_sync(pdata->dev);
1045
1046        /* Set value first to avoid glitching */
1047        ti_sn_bridge_gpio_set(chip, offset, val);
1048
1049        /* Set direction */
1050        ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1051                                 SN_GPIO_MUX_MASK << shift,
1052                                 SN_GPIO_MUX_OUTPUT << shift);
1053        if (ret) {
1054                clear_bit(offset, pdata->gchip_output);
1055                pm_runtime_put(pdata->dev);
1056        }
1057
1058        return ret;
1059}
1060
1061static void ti_sn_bridge_gpio_free(struct gpio_chip *chip, unsigned int offset)
1062{
1063        /* We won't keep pm_runtime if we're input, so switch there on free */
1064        ti_sn_bridge_gpio_direction_input(chip, offset);
1065}
1066
1067static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = {
1068        "GPIO1", "GPIO2", "GPIO3", "GPIO4"
1069};
1070
1071static int ti_sn_setup_gpio_controller(struct ti_sn_bridge *pdata)
1072{
1073        int ret;
1074
1075        /* Only init if someone is going to use us as a GPIO controller */
1076        if (!of_property_read_bool(pdata->dev->of_node, "gpio-controller"))
1077                return 0;
1078
1079        pdata->gchip.label = dev_name(pdata->dev);
1080        pdata->gchip.parent = pdata->dev;
1081        pdata->gchip.owner = THIS_MODULE;
1082        pdata->gchip.of_xlate = tn_sn_bridge_of_xlate;
1083        pdata->gchip.of_gpio_n_cells = 2;
1084        pdata->gchip.free = ti_sn_bridge_gpio_free;
1085        pdata->gchip.get_direction = ti_sn_bridge_gpio_get_direction;
1086        pdata->gchip.direction_input = ti_sn_bridge_gpio_direction_input;
1087        pdata->gchip.direction_output = ti_sn_bridge_gpio_direction_output;
1088        pdata->gchip.get = ti_sn_bridge_gpio_get;
1089        pdata->gchip.set = ti_sn_bridge_gpio_set;
1090        pdata->gchip.can_sleep = true;
1091        pdata->gchip.names = ti_sn_bridge_gpio_names;
1092        pdata->gchip.ngpio = SN_NUM_GPIOS;
1093        pdata->gchip.base = -1;
1094        ret = devm_gpiochip_add_data(pdata->dev, &pdata->gchip, pdata);
1095        if (ret)
1096                dev_err(pdata->dev, "can't add gpio chip\n");
1097
1098        return ret;
1099}
1100
1101#else
1102
1103static inline int ti_sn_setup_gpio_controller(struct ti_sn_bridge *pdata)
1104{
1105        return 0;
1106}
1107
1108#endif
1109
1110static void ti_sn_bridge_parse_lanes(struct ti_sn_bridge *pdata,
1111                                     struct device_node *np)
1112{
1113        u32 lane_assignments[SN_MAX_DP_LANES] = { 0, 1, 2, 3 };
1114        u32 lane_polarities[SN_MAX_DP_LANES] = { };
1115        struct device_node *endpoint;
1116        u8 ln_assign = 0;
1117        u8 ln_polrs = 0;
1118        int dp_lanes;
1119        int i;
1120
1121        /*
1122         * Read config from the device tree about lane remapping and lane
1123         * polarities.  These are optional and we assume identity map and
1124         * normal polarity if nothing is specified.  It's OK to specify just
1125         * data-lanes but not lane-polarities but not vice versa.
1126         *
1127         * Error checking is light (we just make sure we don't crash or
1128         * buffer overrun) and we assume dts is well formed and specifying
1129         * mappings that the hardware supports.
1130         */
1131        endpoint = of_graph_get_endpoint_by_regs(np, 1, -1);
1132        dp_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
1133        if (dp_lanes > 0 && dp_lanes <= SN_MAX_DP_LANES) {
1134                of_property_read_u32_array(endpoint, "data-lanes",
1135                                           lane_assignments, dp_lanes);
1136                of_property_read_u32_array(endpoint, "lane-polarities",
1137                                           lane_polarities, dp_lanes);
1138        } else {
1139                dp_lanes = SN_MAX_DP_LANES;
1140        }
1141        of_node_put(endpoint);
1142
1143        /*
1144         * Convert into register format.  Loop over all lanes even if
1145         * data-lanes had fewer elements so that we nicely initialize
1146         * the LN_ASSIGN register.
1147         */
1148        for (i = SN_MAX_DP_LANES - 1; i >= 0; i--) {
1149                ln_assign = ln_assign << LN_ASSIGN_WIDTH | lane_assignments[i];
1150                ln_polrs = ln_polrs << 1 | lane_polarities[i];
1151        }
1152
1153        /* Stash in our struct for when we power on */
1154        pdata->dp_lanes = dp_lanes;
1155        pdata->ln_assign = ln_assign;
1156        pdata->ln_polrs = ln_polrs;
1157}
1158
1159static int ti_sn_bridge_probe(struct i2c_client *client,
1160                              const struct i2c_device_id *id)
1161{
1162        struct ti_sn_bridge *pdata;
1163        int ret;
1164
1165        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1166                DRM_ERROR("device doesn't support I2C\n");
1167                return -ENODEV;
1168        }
1169
1170        pdata = devm_kzalloc(&client->dev, sizeof(struct ti_sn_bridge),
1171                             GFP_KERNEL);
1172        if (!pdata)
1173                return -ENOMEM;
1174
1175        pdata->regmap = devm_regmap_init_i2c(client,
1176                                             &ti_sn_bridge_regmap_config);
1177        if (IS_ERR(pdata->regmap)) {
1178                DRM_ERROR("regmap i2c init failed\n");
1179                return PTR_ERR(pdata->regmap);
1180        }
1181
1182        pdata->dev = &client->dev;
1183
1184        ret = drm_of_find_panel_or_bridge(pdata->dev->of_node, 1, 0,
1185                                          &pdata->panel, NULL);
1186        if (ret) {
1187                DRM_ERROR("could not find any panel node\n");
1188                return ret;
1189        }
1190
1191        dev_set_drvdata(&client->dev, pdata);
1192
1193        pdata->enable_gpio = devm_gpiod_get(pdata->dev, "enable",
1194                                            GPIOD_OUT_LOW);
1195        if (IS_ERR(pdata->enable_gpio)) {
1196                DRM_ERROR("failed to get enable gpio from DT\n");
1197                ret = PTR_ERR(pdata->enable_gpio);
1198                return ret;
1199        }
1200
1201        ti_sn_bridge_parse_lanes(pdata, client->dev.of_node);
1202
1203        ret = ti_sn_bridge_parse_regulators(pdata);
1204        if (ret) {
1205                DRM_ERROR("failed to parse regulators\n");
1206                return ret;
1207        }
1208
1209        pdata->refclk = devm_clk_get(pdata->dev, "refclk");
1210        if (IS_ERR(pdata->refclk)) {
1211                ret = PTR_ERR(pdata->refclk);
1212                if (ret == -EPROBE_DEFER)
1213                        return ret;
1214                DRM_DEBUG_KMS("refclk not found\n");
1215                pdata->refclk = NULL;
1216        }
1217
1218        ret = ti_sn_bridge_parse_dsi_host(pdata);
1219        if (ret)
1220                return ret;
1221
1222        pm_runtime_enable(pdata->dev);
1223
1224        ret = ti_sn_setup_gpio_controller(pdata);
1225        if (ret) {
1226                pm_runtime_disable(pdata->dev);
1227                return ret;
1228        }
1229
1230        i2c_set_clientdata(client, pdata);
1231
1232        pdata->aux.name = "ti-sn65dsi86-aux";
1233        pdata->aux.dev = pdata->dev;
1234        pdata->aux.transfer = ti_sn_aux_transfer;
1235        drm_dp_aux_register(&pdata->aux);
1236
1237        pdata->bridge.funcs = &ti_sn_bridge_funcs;
1238        pdata->bridge.of_node = client->dev.of_node;
1239
1240        drm_bridge_add(&pdata->bridge);
1241
1242        ti_sn_debugfs_init(pdata);
1243
1244        return 0;
1245}
1246
1247static int ti_sn_bridge_remove(struct i2c_client *client)
1248{
1249        struct ti_sn_bridge *pdata = i2c_get_clientdata(client);
1250
1251        if (!pdata)
1252                return -EINVAL;
1253
1254        ti_sn_debugfs_remove(pdata);
1255
1256        of_node_put(pdata->host_node);
1257
1258        pm_runtime_disable(pdata->dev);
1259
1260        if (pdata->dsi) {
1261                mipi_dsi_detach(pdata->dsi);
1262                mipi_dsi_device_unregister(pdata->dsi);
1263        }
1264
1265        drm_bridge_remove(&pdata->bridge);
1266
1267        return 0;
1268}
1269
1270static struct i2c_device_id ti_sn_bridge_id[] = {
1271        { "ti,sn65dsi86", 0},
1272        {},
1273};
1274MODULE_DEVICE_TABLE(i2c, ti_sn_bridge_id);
1275
1276static const struct of_device_id ti_sn_bridge_match_table[] = {
1277        {.compatible = "ti,sn65dsi86"},
1278        {},
1279};
1280MODULE_DEVICE_TABLE(of, ti_sn_bridge_match_table);
1281
1282static struct i2c_driver ti_sn_bridge_driver = {
1283        .driver = {
1284                .name = "ti_sn65dsi86",
1285                .of_match_table = ti_sn_bridge_match_table,
1286                .pm = &ti_sn_bridge_pm_ops,
1287        },
1288        .probe = ti_sn_bridge_probe,
1289        .remove = ti_sn_bridge_remove,
1290        .id_table = ti_sn_bridge_id,
1291};
1292module_i2c_driver(ti_sn_bridge_driver);
1293
1294MODULE_AUTHOR("Sandeep Panda <spanda@codeaurora.org>");
1295MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
1296MODULE_LICENSE("GPL v2");
1297