drivers/gpu/drm/rockchip/rockchip_lvds.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
   4  * Author:
   5  *      Mark Yao <mark.yao@rock-chips.com>
   6  *      Sandy Huang <hjc@rock-chips.com>
   7  */
   8
   9 #include <drm/drmP.h>
  10 #include <drm/drm_atomic_helper.h>
  11 #include <drm/drm_dp_helper.h>
  12 #include <drm/drm_panel.h>
  13 #include <drm/drm_of.h>
  14 #include <drm/drm_probe_helper.h>
  15
  16 #include <linux/component.h>
  17 #include <linux/clk.h>
  18 #include <linux/mfd/syscon.h>
  19 #include <linux/of_graph.h>
  20 #include <linux/pinctrl/devinfo.h>
  21 #include <linux/pm_runtime.h>
  22 #include <linux/regmap.h>
  23 #include <linux/reset.h>
  24
  25 #include "rockchip_drm_drv.h"
  26 #include "rockchip_drm_vop.h"
  27 #include "rockchip_lvds.h"
  28
  29 #define DISPLAY_OUTPUT_RGB              0
  30 #define DISPLAY_OUTPUT_LVDS             1
  31 #define DISPLAY_OUTPUT_DUAL_LVDS        2
  32
  33 #define connector_to_lvds(c) \
  34                 container_of(c, struct rockchip_lvds, connector)
  35
  36 #define encoder_to_lvds(c) \
  37                 container_of(c, struct rockchip_lvds, encoder)
  38
  39 /**
  40  * rockchip_lvds_soc_data - rockchip lvds Soc private data
  41  * @ch1_offset: lvds channel 1 registe offset
  42  * grf_soc_con6: general registe offset for LVDS contrl
  43  * grf_soc_con7: general registe offset for LVDS contrl
  44  * has_vop_sel: to indicate whether need to choose from different VOP.
  45  */
  46 struct rockchip_lvds_soc_data {
  47         u32 ch1_offset;
  48         int grf_soc_con6;
  49         int grf_soc_con7;
  50         bool has_vop_sel;
  51 };
  52
  53 struct rockchip_lvds {
  54         struct device *dev;
  55         void __iomem *regs;
  56         struct regmap *grf;
  57         struct clk *pclk;
  58         const struct rockchip_lvds_soc_data *soc_data;
  59         int output; /* rgb lvds or dual lvds output */
  60         int format; /* vesa or jeida format */
  61         struct drm_device *drm_dev;
  62         struct drm_panel *panel;
  63         struct drm_bridge *bridge;
  64         struct drm_connector connector;
  65         struct drm_encoder encoder;
  66         struct dev_pin_info *pins;
  67 };
  68
  69 static inline void lvds_writel(struct rockchip_lvds *lvds, u32 offset, u32 val)
  70 {
  71         writel_relaxed(val, lvds->regs + offset);
  72         if (lvds->output == DISPLAY_OUTPUT_LVDS)
  73                 return;
  74         writel_relaxed(val, lvds->regs + offset + lvds->soc_data->ch1_offset);
  75 }
  76
  77 static inline int lvds_name_to_format(const char *s)
  78 {
  79         if (strncmp(s, "jeida-18", 8) == 0)
  80                 return LVDS_JEIDA_18;
  81         else if (strncmp(s, "jeida-24", 8) == 0)
  82                 return LVDS_JEIDA_24;
  83         else if (strncmp(s, "vesa-24", 7) == 0)
  84                 return LVDS_VESA_24;
  85
  86         return -EINVAL;
  87 }
  88
  89 static inline int lvds_name_to_output(const char *s)
  90 {
  91         if (strncmp(s, "rgb", 3) == 0)
  92                 return DISPLAY_OUTPUT_RGB;
  93         else if (strncmp(s, "lvds", 4) == 0)
  94                 return DISPLAY_OUTPUT_LVDS;
  95         else if (strncmp(s, "duallvds", 8) == 0)
  96                 return DISPLAY_OUTPUT_DUAL_LVDS;
  97
  98         return -EINVAL;
  99 }
 100
 101 static int rockchip_lvds_poweron(struct rockchip_lvds *lvds)
 102 {
 103         int ret;
 104         u32 val;
 105
 106         ret = clk_enable(lvds->pclk);
 107         if (ret < 0) {
 108                 DRM_DEV_ERROR(lvds->dev, "failed to enable lvds pclk %d\n", ret);
 109                 return ret;
 110         }
 111         ret = pm_runtime_get_sync(lvds->dev);
 112         if (ret < 0) {
 113                 DRM_DEV_ERROR(lvds->dev, "failed to get pm runtime: %d\n", ret);
 114                 clk_disable(lvds->pclk);
 115                 return ret;
 116         }
 117         val = RK3288_LVDS_CH0_REG0_LANE4_EN | RK3288_LVDS_CH0_REG0_LANE3_EN |
 118                 RK3288_LVDS_CH0_REG0_LANE2_EN | RK3288_LVDS_CH0_REG0_LANE1_EN |
 119                 RK3288_LVDS_CH0_REG0_LANE0_EN;
 120         if (lvds->output == DISPLAY_OUTPUT_RGB) {
 121                 val |= RK3288_LVDS_CH0_REG0_TTL_EN |
 122                         RK3288_LVDS_CH0_REG0_LANECK_EN;
 123                 lvds_writel(lvds, RK3288_LVDS_CH0_REG0, val);
 124                 lvds_writel(lvds, RK3288_LVDS_CH0_REG2,
 125                             RK3288_LVDS_PLL_FBDIV_REG2(0x46));
 126                 lvds_writel(lvds, RK3288_LVDS_CH0_REG4,
 127                             RK3288_LVDS_CH0_REG4_LANECK_TTL_MODE |
 128                             RK3288_LVDS_CH0_REG4_LANE4_TTL_MODE |
 129                             RK3288_LVDS_CH0_REG4_LANE3_TTL_MODE |
 130                             RK3288_LVDS_CH0_REG4_LANE2_TTL_MODE |
 131                             RK3288_LVDS_CH0_REG4_LANE1_TTL_MODE |
 132                             RK3288_LVDS_CH0_REG4_LANE0_TTL_MODE);
 133                 lvds_writel(lvds, RK3288_LVDS_CH0_REG5,
 134                             RK3288_LVDS_CH0_REG5_LANECK_TTL_DATA |
 135                             RK3288_LVDS_CH0_REG5_LANE4_TTL_DATA |
 136                             RK3288_LVDS_CH0_REG5_LANE3_TTL_DATA |
 137                             RK3288_LVDS_CH0_REG5_LANE2_TTL_DATA |
 138                             RK3288_LVDS_CH0_REG5_LANE1_TTL_DATA |
 139                             RK3288_LVDS_CH0_REG5_LANE0_TTL_DATA);
 140         } else {
 141                 val |= RK3288_LVDS_CH0_REG0_LVDS_EN |
 142                             RK3288_LVDS_CH0_REG0_LANECK_EN;
 143                 lvds_writel(lvds, RK3288_LVDS_CH0_REG0, val);
 144                 lvds_writel(lvds, RK3288_LVDS_CH0_REG1,
 145                             RK3288_LVDS_CH0_REG1_LANECK_BIAS |
 146                             RK3288_LVDS_CH0_REG1_LANE4_BIAS |
 147                             RK3288_LVDS_CH0_REG1_LANE3_BIAS |
 148                             RK3288_LVDS_CH0_REG1_LANE2_BIAS |
 149                             RK3288_LVDS_CH0_REG1_LANE1_BIAS |
 150                             RK3288_LVDS_CH0_REG1_LANE0_BIAS);
 151                 lvds_writel(lvds, RK3288_LVDS_CH0_REG2,
 152                             RK3288_LVDS_CH0_REG2_RESERVE_ON |
 153                             RK3288_LVDS_CH0_REG2_LANECK_LVDS_MODE |
 154                             RK3288_LVDS_CH0_REG2_LANE4_LVDS_MODE |
 155                             RK3288_LVDS_CH0_REG2_LANE3_LVDS_MODE |
 156                             RK3288_LVDS_CH0_REG2_LANE2_LVDS_MODE |
 157                             RK3288_LVDS_CH0_REG2_LANE1_LVDS_MODE |
 158                             RK3288_LVDS_CH0_REG2_LANE0_LVDS_MODE |
 159                             RK3288_LVDS_PLL_FBDIV_REG2(0x46));
 160                 lvds_writel(lvds, RK3288_LVDS_CH0_REG4, 0x00);
 161                 lvds_writel(lvds, RK3288_LVDS_CH0_REG5, 0x00);
 162         }
 163         lvds_writel(lvds, RK3288_LVDS_CH0_REG3, RK3288_LVDS_PLL_FBDIV_REG3(0x46));
 164         lvds_writel(lvds, RK3288_LVDS_CH0_REGD, RK3288_LVDS_PLL_PREDIV_REGD(0x0a));
 165         lvds_writel(lvds, RK3288_LVDS_CH0_REG20, RK3288_LVDS_CH0_REG20_LSB);
 166
 167         lvds_writel(lvds, RK3288_LVDS_CFG_REGC, RK3288_LVDS_CFG_REGC_PLL_ENABLE);
 168         lvds_writel(lvds, RK3288_LVDS_CFG_REG21, RK3288_LVDS_CFG_REG21_TX_ENABLE);
 169
 170         return 0;
 171 }
 172
 173 static void rockchip_lvds_poweroff(struct rockchip_lvds *lvds)
 174 {
 175         int ret;
 176         u32 val;
 177
 178         lvds_writel(lvds, RK3288_LVDS_CFG_REG21, RK3288_LVDS_CFG_REG21_TX_ENABLE);
 179         lvds_writel(lvds, RK3288_LVDS_CFG_REGC, RK3288_LVDS_CFG_REGC_PLL_ENABLE);
 180         val = LVDS_DUAL | LVDS_TTL_EN | LVDS_CH0_EN | LVDS_CH1_EN | LVDS_PWRDN;
 181         val |= val << 16;
 182         ret = regmap_write(lvds->grf, lvds->soc_data->grf_soc_con7, val);
 183         if (ret != 0)
 184                 DRM_DEV_ERROR(lvds->dev, "Could not write to GRF: %d\n", ret);
 185
 186         pm_runtime_put(lvds->dev);
 187         clk_disable(lvds->pclk);
 188 }
 189
 190 static const struct drm_connector_funcs rockchip_lvds_connector_funcs = {
 191         .fill_modes = drm_helper_probe_single_connector_modes,
 192         .destroy = drm_connector_cleanup,
 193         .reset = drm_atomic_helper_connector_reset,
 194         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 195         .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 196 };
 197
 198 static int rockchip_lvds_connector_get_modes(struct drm_connector *connector)
 199 {
 200         struct rockchip_lvds *lvds = connector_to_lvds(connector);
 201         struct drm_panel *panel = lvds->panel;
 202
 203         return drm_panel_get_modes(panel);
 204 }
 205
 206 static const
 207 struct drm_connector_helper_funcs rockchip_lvds_connector_helper_funcs = {
 208         .get_modes = rockchip_lvds_connector_get_modes,
 209 };
 210
 211 static void rockchip_lvds_grf_config(struct drm_encoder *encoder,
 212                                      struct drm_display_mode *mode)
 213 {
 214         struct rockchip_lvds *lvds = encoder_to_lvds(encoder);
 215         u8 pin_hsync = (mode->flags & DRM_MODE_FLAG_PHSYNC) ? 1 : 0;
 216         u8 pin_dclk = (mode->flags & DRM_MODE_FLAG_PCSYNC) ? 1 : 0;
 217         u32 val;
 218         int ret;
 219
 220         /* iomux to LCD data/sync mode */
 221         if (lvds->output == DISPLAY_OUTPUT_RGB)
 222                 if (lvds->pins && !IS_ERR(lvds->pins->default_state))
 223                         pinctrl_select_state(lvds->pins->p,
 224                                              lvds->pins->default_state);
 225         val = lvds->format | LVDS_CH0_EN;
 226         if (lvds->output == DISPLAY_OUTPUT_RGB)
 227                 val |= LVDS_TTL_EN | LVDS_CH1_EN;
 228         else if (lvds->output == DISPLAY_OUTPUT_DUAL_LVDS)
 229                 val |= LVDS_DUAL | LVDS_CH1_EN;
 230
 231         if ((mode->htotal - mode->hsync_start) & 0x01)
 232                 val |= LVDS_START_PHASE_RST_1;
 233
 234         val |= (pin_dclk << 8) | (pin_hsync << 9);
 235         val |= (0xffff << 16);
 236         ret = regmap_write(lvds->grf, lvds->soc_data->grf_soc_con7, val);
 237         if (ret != 0) {
 238                 DRM_DEV_ERROR(lvds->dev, "Could not write to GRF: %d\n", ret);
 239                 return;
 240         }
 241 }
 242
 243 static int rockchip_lvds_set_vop_source(struct rockchip_lvds *lvds,
 244                                         struct drm_encoder *encoder)
 245 {
 246         u32 val;
 247         int ret;
 248
 249         if (!lvds->soc_data->has_vop_sel)
 250                 return 0;
 251
 252         ret = drm_of_encoder_active_endpoint_id(lvds->dev->of_node, encoder);
 253         if (ret < 0)
 254                 return ret;
 255
 256         val = RK3288_LVDS_SOC_CON6_SEL_VOP_LIT << 16;
 257         if (ret)
 258                 val |= RK3288_LVDS_SOC_CON6_SEL_VOP_LIT;
 259
 260         ret = regmap_write(lvds->grf, lvds->soc_data->grf_soc_con6, val);
 261         if (ret < 0)
 262                 return ret;
 263
 264         return 0;
 265 }
 266
 267 static int
 268 rockchip_lvds_encoder_atomic_check(struct drm_encoder *encoder,
 269                                    struct drm_crtc_state *crtc_state,
 270                                    struct drm_connector_state *conn_state)
 271 {
 272         struct rockchip_crtc_state *s = to_rockchip_crtc_state(crtc_state);
 273
 274         s->output_mode = ROCKCHIP_OUT_MODE_P888;
 275         s->output_type = DRM_MODE_CONNECTOR_LVDS;
 276
 277         return 0;
 278 }
 279
 280 static void rockchip_lvds_encoder_enable(struct drm_encoder *encoder)
 281 {
 282         struct rockchip_lvds *lvds = encoder_to_lvds(encoder);
 283         struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
 284         int ret;
 285
 286         drm_panel_prepare(lvds->panel);
 287         ret = rockchip_lvds_poweron(lvds);
 288         if (ret < 0) {
 289                 DRM_DEV_ERROR(lvds->dev, "failed to power on lvds: %d\n", ret);
 290                 drm_panel_unprepare(lvds->panel);
 291         }
 292         rockchip_lvds_grf_config(encoder, mode);
 293         rockchip_lvds_set_vop_source(lvds, encoder);
 294         drm_panel_enable(lvds->panel);
 295 }
 296
 297 static void rockchip_lvds_encoder_disable(struct drm_encoder *encoder)
 298 {
 299         struct rockchip_lvds *lvds = encoder_to_lvds(encoder);
 300
 301         drm_panel_disable(lvds->panel);
 302         rockchip_lvds_poweroff(lvds);
 303         drm_panel_unprepare(lvds->panel);
 304 }
 305
 306 static const
 307 struct drm_encoder_helper_funcs rockchip_lvds_encoder_helper_funcs = {
 308         .enable = rockchip_lvds_encoder_enable,
 309         .disable = rockchip_lvds_encoder_disable,
 310         .atomic_check = rockchip_lvds_encoder_atomic_check,
 311 };
 312
 313 static const struct drm_encoder_funcs rockchip_lvds_encoder_funcs = {
 314         .destroy = drm_encoder_cleanup,
 315 };
 316
 317 static const struct rockchip_lvds_soc_data rk3288_lvds_data = {
 318         .ch1_offset = 0x100,
 319         .grf_soc_con6 = 0x025c,
 320         .grf_soc_con7 = 0x0260,
 321         .has_vop_sel = true,
 322 };
 323
 324 static const struct of_device_id rockchip_lvds_dt_ids[] = {
 325         {
 326                 .compatible = "rockchip,rk3288-lvds",
 327                 .data = &rk3288_lvds_data
 328         },
 329         {}
 330 };
 331 MODULE_DEVICE_TABLE(of, rockchip_lvds_dt_ids);
 332
 333 static int rockchip_lvds_bind(struct device *dev, struct device *master,
 334                               void *data)
 335 {
 336         struct rockchip_lvds *lvds = dev_get_drvdata(dev);
 337         struct drm_device *drm_dev = data;
 338         struct drm_encoder *encoder;
 339         struct drm_connector *connector;
 340         struct device_node *remote = NULL;
 341         struct device_node  *port, *endpoint;
 342         int ret = 0, child_count = 0;
 343         const char *name;
 344         u32 endpoint_id;
 345
 346         lvds->drm_dev = drm_dev;
 347         port = of_graph_get_port_by_id(dev->of_node, 1);
 348         if (!port) {
 349                 DRM_DEV_ERROR(dev,
 350                               "can't found port point, please init lvds panel port!\n");
 351                 return -EINVAL;
 352         }
 353         for_each_child_of_node(port, endpoint) {
 354                 child_count++;
 355                 of_property_read_u32(endpoint, "reg", &endpoint_id);
 356                 ret = drm_of_find_panel_or_bridge(dev->of_node, 1, endpoint_id,
 357                                                   &lvds->panel, &lvds->bridge);
 358                 if (!ret) {
 359                         of_node_put(endpoint);
 360                         break;
 361                 }
 362         }
 363         if (!child_count) {
 364                 DRM_DEV_ERROR(dev, "lvds port does not have any children\n");
 365                 ret = -EINVAL;
 366                 goto err_put_port;
 367         } else if (ret) {
 368                 DRM_DEV_ERROR(dev, "failed to find panel and bridge node\n");
 369                 ret = -EPROBE_DEFER;
 370                 goto err_put_port;
 371         }
 372         if (lvds->panel)
 373                 remote = lvds->panel->dev->of_node;
 374         else
 375                 remote = lvds->bridge->of_node;
 376         if (of_property_read_string(dev->of_node, "rockchip,output", &name))
 377                 /* default set it as output rgb */
 378                 lvds->output = DISPLAY_OUTPUT_RGB;
 379         else
 380                 lvds->output = lvds_name_to_output(name);
 381
 382         if (lvds->output < 0) {
 383                 DRM_DEV_ERROR(dev, "invalid output type [%s]\n", name);
 384                 ret = lvds->output;
 385                 goto err_put_remote;
 386         }
 387
 388         if (of_property_read_string(remote, "data-mapping", &name))
 389                 /* default set it as format vesa 18 */
 390                 lvds->format = LVDS_VESA_18;
 391         else
 392                 lvds->format = lvds_name_to_format(name);
 393
 394         if (lvds->format < 0) {
 395                 DRM_DEV_ERROR(dev, "invalid data-mapping format [%s]\n", name);
 396                 ret = lvds->format;
 397                 goto err_put_remote;
 398         }
 399
 400         encoder = &lvds->encoder;
 401         encoder->possible_crtcs = drm_of_find_possible_crtcs(drm_dev,
 402                                                              dev->of_node);
 403
 404         ret = drm_encoder_init(drm_dev, encoder, &rockchip_lvds_encoder_funcs,
 405                                DRM_MODE_ENCODER_LVDS, NULL);
 406         if (ret < 0) {
 407                 DRM_DEV_ERROR(drm_dev->dev,
 408                               "failed to initialize encoder: %d\n", ret);
 409                 goto err_put_remote;
 410         }
 411
 412         drm_encoder_helper_add(encoder, &rockchip_lvds_encoder_helper_funcs);
 413
 414         if (lvds->panel) {
 415                 connector = &lvds->connector;
 416                 connector->dpms = DRM_MODE_DPMS_OFF;
 417                 ret = drm_connector_init(drm_dev, connector,
 418                                          &rockchip_lvds_connector_funcs,
 419                                          DRM_MODE_CONNECTOR_LVDS);
 420                 if (ret < 0) {
 421                         DRM_DEV_ERROR(drm_dev->dev,
 422                                       "failed to initialize connector: %d\n", ret);
 423                         goto err_free_encoder;
 424                 }
 425
 426                 drm_connector_helper_add(connector,
 427                                          &rockchip_lvds_connector_helper_funcs);
 428
 429                 ret = drm_connector_attach_encoder(connector, encoder);
 430                 if (ret < 0) {
 431                         DRM_DEV_ERROR(drm_dev->dev,
 432                                       "failed to attach encoder: %d\n", ret);
 433                         goto err_free_connector;
 434                 }
 435
 436                 ret = drm_panel_attach(lvds->panel, connector);
 437                 if (ret < 0) {
 438                         DRM_DEV_ERROR(drm_dev->dev,
 439                                       "failed to attach panel: %d\n", ret);
 440                         goto err_free_connector;
 441                 }
 442         } else {
 443                 ret = drm_bridge_attach(encoder, lvds->bridge, NULL);
 444                 if (ret) {
 445                         DRM_DEV_ERROR(drm_dev->dev,
 446                                       "failed to attach bridge: %d\n", ret);
 447                         goto err_free_encoder;
 448                 }
 449         }
 450
 451         pm_runtime_enable(dev);
 452         of_node_put(remote);
 453         of_node_put(port);
 454
 455         return 0;
 456
 457 err_free_connector:
 458         drm_connector_cleanup(connector);
 459 err_free_encoder:
 460         drm_encoder_cleanup(encoder);
 461 err_put_remote:
 462         of_node_put(remote);
 463 err_put_port:
 464         of_node_put(port);
 465
 466         return ret;
 467 }
 468
 469 static void rockchip_lvds_unbind(struct device *dev, struct device *master,
 470                                 void *data)
 471 {
 472         struct rockchip_lvds *lvds = dev_get_drvdata(dev);
 473
 474         rockchip_lvds_encoder_disable(&lvds->encoder);
 475         if (lvds->panel)
 476                 drm_panel_detach(lvds->panel);
 477         pm_runtime_disable(dev);
 478         drm_connector_cleanup(&lvds->connector);
 479         drm_encoder_cleanup(&lvds->encoder);
 480 }
 481
 482 static const struct component_ops rockchip_lvds_component_ops = {
 483         .bind = rockchip_lvds_bind,
 484         .unbind = rockchip_lvds_unbind,
 485 };
 486
 487 static int rockchip_lvds_probe(struct platform_device *pdev)
 488 {
 489         struct device *dev = &pdev->dev;
 490         struct rockchip_lvds *lvds;
 491         const struct of_device_id *match;
 492         struct resource *res;
 493         int ret;
 494
 495         if (!dev->of_node)
 496                 return -ENODEV;
 497
 498         lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
 499         if (!lvds)
 500                 return -ENOMEM;
 501
 502         lvds->dev = dev;
 503         match = of_match_node(rockchip_lvds_dt_ids, dev->of_node);
 504         if (!match)
 505                 return -ENODEV;
 506         lvds->soc_data = match->data;
 507
 508         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 509         lvds->regs = devm_ioremap_resource(&pdev->dev, res);
 510         if (IS_ERR(lvds->regs))
 511                 return PTR_ERR(lvds->regs);
 512
 513         lvds->pclk = devm_clk_get(&pdev->dev, "pclk_lvds");
 514         if (IS_ERR(lvds->pclk)) {
 515                 DRM_DEV_ERROR(dev, "could not get pclk_lvds\n");
 516                 return PTR_ERR(lvds->pclk);
 517         }
 518
 519         lvds->pins = devm_kzalloc(lvds->dev, sizeof(*lvds->pins),
 520                                   GFP_KERNEL);
 521         if (!lvds->pins)
 522                 return -ENOMEM;
 523
 524         lvds->pins->p = devm_pinctrl_get(lvds->dev);
 525         if (IS_ERR(lvds->pins->p)) {
 526                 DRM_DEV_ERROR(dev, "no pinctrl handle\n");
 527                 devm_kfree(lvds->dev, lvds->pins);
 528                 lvds->pins = NULL;
 529         } else {
 530                 lvds->pins->default_state =
 531                         pinctrl_lookup_state(lvds->pins->p, "lcdc");
 532                 if (IS_ERR(lvds->pins->default_state)) {
 533                         DRM_DEV_ERROR(dev, "no default pinctrl state\n");
 534                         devm_kfree(lvds->dev, lvds->pins);
 535                         lvds->pins = NULL;
 536                 }
 537         }
 538
 539         lvds->grf = syscon_regmap_lookup_by_phandle(dev->of_node,
 540                                                     "rockchip,grf");
 541         if (IS_ERR(lvds->grf)) {
 542                 DRM_DEV_ERROR(dev, "missing rockchip,grf property\n");
 543                 return PTR_ERR(lvds->grf);
 544         }
 545
 546         dev_set_drvdata(dev, lvds);
 547
 548         ret = clk_prepare(lvds->pclk);
 549         if (ret < 0) {
 550                 DRM_DEV_ERROR(dev, "failed to prepare pclk_lvds\n");
 551                 return ret;
 552         }
 553         ret = component_add(&pdev->dev, &rockchip_lvds_component_ops);
 554         if (ret < 0) {
 555                 DRM_DEV_ERROR(dev, "failed to add component\n");
 556                 clk_unprepare(lvds->pclk);
 557         }
 558
 559         return ret;
 560 }
 561
 562 static int rockchip_lvds_remove(struct platform_device *pdev)
 563 {
 564         struct rockchip_lvds *lvds = dev_get_drvdata(&pdev->dev);
 565
 566         component_del(&pdev->dev, &rockchip_lvds_component_ops);
 567         clk_unprepare(lvds->pclk);
 568
 569         return 0;
 570 }
 571
 572 struct platform_driver rockchip_lvds_driver = {
 573         .probe = rockchip_lvds_probe,
 574         .remove = rockchip_lvds_remove,
 575         .driver = {
 576                    .name = "rockchip-lvds",
 577                    .of_match_table = of_match_ptr(rockchip_lvds_dt_ids),
 578         },
 579 };