drivers/gpu/drm/imx/lcdc/imx-lcdc.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 // SPDX-FileCopyrightText: 2020 Marian Cichy <[email protected]>
   3
   4 #include <drm/drm_bridge.h>
   5 #include <drm/drm_bridge_connector.h>
   6 #include <drm/drm_client_setup.h>
   7 #include <drm/drm_damage_helper.h>
   8 #include <drm/drm_drv.h>
   9 #include <drm/drm_fbdev_dma.h>
  10 #include <drm/drm_fb_dma_helper.h>
  11 #include <drm/drm_fourcc.h>
  12 #include <drm/drm_framebuffer.h>
  13 #include <drm/drm_gem_atomic_helper.h>
  14 #include <drm/drm_gem_dma_helper.h>
  15 #include <drm/drm_gem_framebuffer_helper.h>
  16 #include <drm/drm_of.h>
  17 #include <drm/drm_probe_helper.h>
  18 #include <drm/drm_simple_kms_helper.h>
  19 #include <drm/drm_vblank.h>
  20 #include <linux/bitfield.h>
  21 #include <linux/clk.h>
  22 #include <linux/dma-mapping.h>
  23 #include <linux/mod_devicetable.h>
  24 #include <linux/module.h>
  25 #include <linux/platform_device.h>
  26
  27 #define IMX21LCDC_LSSAR         0x0000 /* LCDC Screen Start Address Register */
  28 #define IMX21LCDC_LSR           0x0004 /* LCDC Size Register */
  29 #define IMX21LCDC_LVPWR         0x0008 /* LCDC Virtual Page Width Register */
  30 #define IMX21LCDC_LCPR          0x000C /* LCDC Cursor Position Register */
  31 #define IMX21LCDC_LCWHB         0x0010 /* LCDC Cursor Width Height and Blink Register*/
  32 #define IMX21LCDC_LCCMR         0x0014 /* LCDC Color Cursor Mapping Register */
  33 #define IMX21LCDC_LPCR          0x0018 /* LCDC Panel Configuration Register */
  34 #define IMX21LCDC_LHCR          0x001C /* LCDC Horizontal Configuration Register */
  35 #define IMX21LCDC_LVCR          0x0020 /* LCDC Vertical Configuration Register */
  36 #define IMX21LCDC_LPOR          0x0024 /* LCDC Panning Offset Register */
  37 #define IMX21LCDC_LSCR          0x0028 /* LCDC Sharp Configuration Register */
  38 #define IMX21LCDC_LPCCR         0x002C /* LCDC PWM Contrast Control Register */
  39 #define IMX21LCDC_LDCR          0x0030 /* LCDC DMA Control Register */
  40 #define IMX21LCDC_LRMCR         0x0034 /* LCDC Refresh Mode Control Register */
  41 #define IMX21LCDC_LICR          0x0038 /* LCDC Interrupt Configuration Register */
  42 #define IMX21LCDC_LIER          0x003C /* LCDC Interrupt Enable Register */
  43 #define IMX21LCDC_LISR          0x0040 /* LCDC Interrupt Status Register */
  44 #define IMX21LCDC_LGWSAR        0x0050 /* LCDC Graphic Window Start Address Register */
  45 #define IMX21LCDC_LGWSR         0x0054 /* LCDC Graph Window Size Register */
  46 #define IMX21LCDC_LGWVPWR       0x0058 /* LCDC Graphic Window Virtual Page Width Register */
  47 #define IMX21LCDC_LGWPOR        0x005C /* LCDC Graphic Window Panning Offset Register */
  48 #define IMX21LCDC_LGWPR         0x0060 /* LCDC Graphic Window Position Register */
  49 #define IMX21LCDC_LGWCR         0x0064 /* LCDC Graphic Window Control Register */
  50 #define IMX21LCDC_LGWDCR        0x0068 /* LCDC Graphic Window DMA Control Register */
  51 #define IMX21LCDC_LAUSCR        0x0080 /* LCDC AUS Mode Control Register */
  52 #define IMX21LCDC_LAUSCCR       0x0084 /* LCDC AUS Mode Cursor Control Register */
  53 #define IMX21LCDC_BGLUT         0x0800 /* Background Lookup Table */
  54 #define IMX21LCDC_GWLUT         0x0C00 /* Graphic Window Lookup Table */
  55
  56 #define IMX21LCDC_LCPR_CC0 BIT(30) /* Cursor Control Bit 0 */
  57 #define IMX21LCDC_LCPR_CC1 BIT(31) /* Cursor Control Bit 1 */
  58
  59 /* Values HSYNC, VSYNC and Framesize Register */
  60 #define IMX21LCDC_LHCR_HWIDTH           GENMASK(31, 26)
  61 #define IMX21LCDC_LHCR_HFPORCH          GENMASK(15, 8)          /* H_WAIT_1 in the i.MX25 Reference manual */
  62 #define IMX21LCDC_LHCR_HBPORCH          GENMASK(7, 0)           /* H_WAIT_2 in the i.MX25 Reference manual */
  63
  64 #define IMX21LCDC_LVCR_VWIDTH           GENMASK(31, 26)
  65 #define IMX21LCDC_LVCR_VFPORCH          GENMASK(15, 8)          /* V_WAIT_1 in the i.MX25 Reference manual */
  66 #define IMX21LCDC_LVCR_VBPORCH          GENMASK(7, 0)           /* V_WAIT_2 in the i.MX25 Reference manual */
  67
  68 #define IMX21LCDC_LSR_XMAX              GENMASK(25, 20)
  69 #define IMX21LCDC_LSR_YMAX              GENMASK(9, 0)
  70
  71 /* Values for LPCR Register */
  72 #define IMX21LCDC_LPCR_PCD              GENMASK(5, 0)
  73 #define IMX21LCDC_LPCR_SHARP            BIT(6)
  74 #define IMX21LCDC_LPCR_SCLKSEL          BIT(7)
  75 #define IMX21LCDC_LPCR_ACD              GENMASK(14, 8)
  76 #define IMX21LCDC_LPCR_ACDSEL           BIT(15)
  77 #define IMX21LCDC_LPCR_REV_VS           BIT(16)
  78 #define IMX21LCDC_LPCR_SWAP_SEL         BIT(17)
  79 #define IMX21LCDC_LPCR_END_SEL          BIT(18)
  80 #define IMX21LCDC_LPCR_SCLKIDLE         BIT(19)
  81 #define IMX21LCDC_LPCR_OEPOL            BIT(20)
  82 #define IMX21LCDC_LPCR_CLKPOL           BIT(21)
  83 #define IMX21LCDC_LPCR_LPPOL            BIT(22)
  84 #define IMX21LCDC_LPCR_FLMPOL           BIT(23)
  85 #define IMX21LCDC_LPCR_PIXPOL           BIT(24)
  86 #define IMX21LCDC_LPCR_BPIX             GENMASK(27, 25)
  87 #define IMX21LCDC_LPCR_PBSIZ            GENMASK(29, 28)
  88 #define IMX21LCDC_LPCR_COLOR            BIT(30)
  89 #define IMX21LCDC_LPCR_TFT              BIT(31)
  90
  91 #define INTR_EOF BIT(1) /* VBLANK Interrupt Bit */
  92
  93 #define BPP_RGB565      0x05
  94 #define BPP_XRGB8888    0x07
  95
  96 #define LCDC_MIN_XRES 64
  97 #define LCDC_MIN_YRES 64
  98
  99 #define LCDC_MAX_XRES 1024
 100 #define LCDC_MAX_YRES 1024
 101
 102 struct imx_lcdc {
 103         struct drm_device drm;
 104         struct drm_simple_display_pipe pipe;
 105         struct drm_connector *connector;
 106         void __iomem *base;
 107
 108         struct clk *clk_ipg;
 109         struct clk *clk_ahb;
 110         struct clk *clk_per;
 111 };
 112
 113 static const u32 imx_lcdc_formats[] = {
 114         DRM_FORMAT_RGB565, DRM_FORMAT_XRGB8888,
 115 };
 116
 117 static inline struct imx_lcdc *imx_lcdc_from_drmdev(struct drm_device *drm)
 118 {
 119         return container_of(drm, struct imx_lcdc, drm);
 120 }
 121
 122 static unsigned int imx_lcdc_get_format(unsigned int drm_format)
 123 {
 124         switch (drm_format) {
 125         default:
 126                 DRM_WARN("Format not supported - fallback to XRGB8888\n");
 127                 fallthrough;
 128
 129         case DRM_FORMAT_XRGB8888:
 130                 return BPP_XRGB8888;
 131
 132         case DRM_FORMAT_RGB565:
 133                 return BPP_RGB565;
 134         }
 135 }
 136
 137 static void imx_lcdc_update_hw_registers(struct drm_simple_display_pipe *pipe,
 138                                          struct drm_plane_state *old_state,
 139                                          bool mode_set)
 140 {
 141         struct drm_crtc *crtc = &pipe->crtc;
 142         struct drm_plane_state *new_state = pipe->plane.state;
 143         struct drm_framebuffer *fb = new_state->fb;
 144         struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(pipe->crtc.dev);
 145         u32 lpcr, lvcr, lhcr;
 146         u32 framesize;
 147         dma_addr_t addr;
 148
 149         addr = drm_fb_dma_get_gem_addr(fb, new_state, 0);
 150         /* The LSSAR register specifies the LCD screen start address (SSA). */
 151         writel(addr, lcdc->base + IMX21LCDC_LSSAR);
 152
 153         if (!mode_set)
 154                 return;
 155
 156         /* Disable PER clock to make register write possible */
 157         if (old_state && old_state->crtc && old_state->crtc->enabled)
 158                 clk_disable_unprepare(lcdc->clk_per);
 159
 160         /* Framesize */
 161         framesize = FIELD_PREP(IMX21LCDC_LSR_XMAX, crtc->mode.hdisplay >> 4) |
 162                 FIELD_PREP(IMX21LCDC_LSR_YMAX, crtc->mode.vdisplay);
 163         writel(framesize, lcdc->base + IMX21LCDC_LSR);
 164
 165         /* HSYNC */
 166         lhcr = FIELD_PREP(IMX21LCDC_LHCR_HFPORCH, crtc->mode.hsync_start - crtc->mode.hdisplay - 1) |
 167                 FIELD_PREP(IMX21LCDC_LHCR_HWIDTH, crtc->mode.hsync_end - crtc->mode.hsync_start - 1) |
 168                 FIELD_PREP(IMX21LCDC_LHCR_HBPORCH, crtc->mode.htotal - crtc->mode.hsync_end - 3);
 169         writel(lhcr, lcdc->base + IMX21LCDC_LHCR);
 170
 171         /* VSYNC */
 172         lvcr = FIELD_PREP(IMX21LCDC_LVCR_VFPORCH, crtc->mode.vsync_start - crtc->mode.vdisplay) |
 173                 FIELD_PREP(IMX21LCDC_LVCR_VWIDTH, crtc->mode.vsync_end - crtc->mode.vsync_start) |
 174                 FIELD_PREP(IMX21LCDC_LVCR_VBPORCH, crtc->mode.vtotal - crtc->mode.vsync_end);
 175         writel(lvcr, lcdc->base + IMX21LCDC_LVCR);
 176
 177         lpcr = readl(lcdc->base + IMX21LCDC_LPCR);
 178         lpcr &= ~IMX21LCDC_LPCR_BPIX;
 179         lpcr |= FIELD_PREP(IMX21LCDC_LPCR_BPIX, imx_lcdc_get_format(fb->format->format));
 180         writel(lpcr, lcdc->base + IMX21LCDC_LPCR);
 181
 182         /* Virtual Page Width */
 183         writel(new_state->fb->pitches[0] / 4, lcdc->base + IMX21LCDC_LVPWR);
 184
 185         /* Enable PER clock */
 186         if (new_state->crtc->enabled)
 187                 clk_prepare_enable(lcdc->clk_per);
 188 }
 189
 190 static void imx_lcdc_pipe_enable(struct drm_simple_display_pipe *pipe,
 191                                  struct drm_crtc_state *crtc_state,
 192                                  struct drm_plane_state *plane_state)
 193 {
 194         int ret;
 195         int clk_div;
 196         int bpp;
 197         struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(pipe->crtc.dev);
 198         struct drm_display_mode *mode = &pipe->crtc.mode;
 199         struct drm_display_info *disp_info = &lcdc->connector->display_info;
 200         const int hsync_pol = (mode->flags & DRM_MODE_FLAG_PHSYNC) ? 0 : 1;
 201         const int vsync_pol = (mode->flags & DRM_MODE_FLAG_PVSYNC) ? 0 : 1;
 202         const int data_enable_pol =
 203                 (disp_info->bus_flags & DRM_BUS_FLAG_DE_HIGH) ? 0 : 1;
 204         const int clk_pol =
 205                 (disp_info->bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE) ? 0 : 1;
 206
 207         clk_div = DIV_ROUND_CLOSEST_ULL(clk_get_rate(lcdc->clk_per),
 208                                         mode->clock * 1000);
 209         bpp = imx_lcdc_get_format(plane_state->fb->format->format);
 210
 211         writel(FIELD_PREP(IMX21LCDC_LPCR_PCD, clk_div - 1) |
 212                FIELD_PREP(IMX21LCDC_LPCR_LPPOL, hsync_pol) |
 213                FIELD_PREP(IMX21LCDC_LPCR_FLMPOL, vsync_pol) |
 214                FIELD_PREP(IMX21LCDC_LPCR_OEPOL, data_enable_pol) |
 215                FIELD_PREP(IMX21LCDC_LPCR_TFT, 1) |
 216                FIELD_PREP(IMX21LCDC_LPCR_COLOR, 1) |
 217                FIELD_PREP(IMX21LCDC_LPCR_PBSIZ, 3) |
 218                FIELD_PREP(IMX21LCDC_LPCR_BPIX, bpp) |
 219                FIELD_PREP(IMX21LCDC_LPCR_SCLKSEL, 1) |
 220                FIELD_PREP(IMX21LCDC_LPCR_PIXPOL, 0) |
 221                FIELD_PREP(IMX21LCDC_LPCR_CLKPOL, clk_pol),
 222                lcdc->base + IMX21LCDC_LPCR);
 223
 224         /* 0px panning offset */
 225         writel(0x00000000, lcdc->base + IMX21LCDC_LPOR);
 226
 227         /* disable hardware cursor */
 228         writel(readl(lcdc->base + IMX21LCDC_LCPR) & ~(IMX21LCDC_LCPR_CC0 | IMX21LCDC_LCPR_CC1),
 229                lcdc->base + IMX21LCDC_LCPR);
 230
 231         ret = clk_prepare_enable(lcdc->clk_ipg);
 232         if (ret) {
 233                 dev_err(pipe->crtc.dev->dev, "Cannot enable ipg clock: %pe\n", ERR_PTR(ret));
 234                 return;
 235         }
 236         ret = clk_prepare_enable(lcdc->clk_ahb);
 237         if (ret) {
 238                 dev_err(pipe->crtc.dev->dev, "Cannot enable ahb clock: %pe\n", ERR_PTR(ret));
 239
 240                 clk_disable_unprepare(lcdc->clk_ipg);
 241
 242                 return;
 243         }
 244
 245         imx_lcdc_update_hw_registers(pipe, NULL, true);
 246
 247         /* Enable VBLANK Interrupt */
 248         writel(INTR_EOF, lcdc->base + IMX21LCDC_LIER);
 249 }
 250
 251 static void imx_lcdc_pipe_disable(struct drm_simple_display_pipe *pipe)
 252 {
 253         struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(pipe->crtc.dev);
 254         struct drm_crtc *crtc = &lcdc->pipe.crtc;
 255         struct drm_pending_vblank_event *event;
 256
 257         clk_disable_unprepare(lcdc->clk_ahb);
 258         clk_disable_unprepare(lcdc->clk_ipg);
 259
 260         if (pipe->crtc.enabled)
 261                 clk_disable_unprepare(lcdc->clk_per);
 262
 263         spin_lock_irq(&lcdc->drm.event_lock);
 264         event = crtc->state->event;
 265         if (event) {
 266                 crtc->state->event = NULL;
 267                 drm_crtc_send_vblank_event(crtc, event);
 268         }
 269         spin_unlock_irq(&lcdc->drm.event_lock);
 270
 271         /* Disable VBLANK Interrupt */
 272         writel(0, lcdc->base + IMX21LCDC_LIER);
 273 }
 274
 275 static int imx_lcdc_pipe_check(struct drm_simple_display_pipe *pipe,
 276                                struct drm_plane_state *plane_state,
 277                                struct drm_crtc_state *crtc_state)
 278 {
 279         const struct drm_display_mode *mode = &crtc_state->mode;
 280         const struct drm_display_mode *old_mode = &pipe->crtc.state->mode;
 281
 282         if (mode->hdisplay < LCDC_MIN_XRES || mode->hdisplay > LCDC_MAX_XRES ||
 283             mode->vdisplay < LCDC_MIN_YRES || mode->vdisplay > LCDC_MAX_YRES ||
 284             mode->hdisplay % 0x10) { /* must be multiple of 16 */
 285                 drm_err(pipe->crtc.dev, "unsupported display mode (%u x %u)\n",
 286                         mode->hdisplay, mode->vdisplay);
 287                 return -EINVAL;
 288         }
 289
 290         crtc_state->mode_changed =
 291                 old_mode->hdisplay != mode->hdisplay ||
 292                 old_mode->vdisplay != mode->vdisplay;
 293
 294         return 0;
 295 }
 296
 297 static void imx_lcdc_pipe_update(struct drm_simple_display_pipe *pipe,
 298                                  struct drm_plane_state *old_state)
 299 {
 300         struct drm_crtc *crtc = &pipe->crtc;
 301         struct drm_pending_vblank_event *event = crtc->state->event;
 302         struct drm_plane_state *new_state = pipe->plane.state;
 303         struct drm_framebuffer *fb = new_state->fb;
 304         struct drm_framebuffer *old_fb = old_state->fb;
 305         struct drm_crtc *old_crtc = old_state->crtc;
 306         bool mode_changed = false;
 307
 308         if (old_fb && old_fb->format != fb->format)
 309                 mode_changed = true;
 310         else if (old_crtc != crtc)
 311                 mode_changed = true;
 312
 313         imx_lcdc_update_hw_registers(pipe, old_state, mode_changed);
 314
 315         if (event) {
 316                 crtc->state->event = NULL;
 317
 318                 spin_lock_irq(&crtc->dev->event_lock);
 319
 320                 if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
 321                         drm_crtc_arm_vblank_event(crtc, event);
 322                 else
 323                         drm_crtc_send_vblank_event(crtc, event);
 324
 325                 spin_unlock_irq(&crtc->dev->event_lock);
 326         }
 327 }
 328
 329 static const struct drm_simple_display_pipe_funcs imx_lcdc_pipe_funcs = {
 330         .enable = imx_lcdc_pipe_enable,
 331         .disable = imx_lcdc_pipe_disable,
 332         .check = imx_lcdc_pipe_check,
 333         .update = imx_lcdc_pipe_update,
 334 };
 335
 336 static const struct drm_mode_config_funcs imx_lcdc_mode_config_funcs = {
 337         .fb_create = drm_gem_fb_create_with_dirty,
 338         .atomic_check = drm_atomic_helper_check,
 339         .atomic_commit = drm_atomic_helper_commit,
 340 };
 341
 342 static const struct drm_mode_config_helper_funcs imx_lcdc_mode_config_helpers = {
 343         .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
 344 };
 345
 346 DEFINE_DRM_GEM_DMA_FOPS(imx_lcdc_drm_fops);
 347
 348 static struct drm_driver imx_lcdc_drm_driver = {
 349         .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
 350         .fops = &imx_lcdc_drm_fops,
 351         DRM_GEM_DMA_DRIVER_OPS_VMAP,
 352         DRM_FBDEV_DMA_DRIVER_OPS,
 353         .name = "imx-lcdc",
 354         .desc = "i.MX LCDC driver",
 355         .date = "20200716",
 356 };
 357
 358 static const struct of_device_id imx_lcdc_of_dev_id[] = {
 359         {
 360                 .compatible = "fsl,imx21-lcdc",
 361         },
 362         {
 363                 .compatible = "fsl,imx25-lcdc",
 364         },
 365         { /* sentinel */ }
 366 };
 367 MODULE_DEVICE_TABLE(of, imx_lcdc_of_dev_id);
 368
 369 static irqreturn_t imx_lcdc_irq_handler(int irq, void *arg)
 370 {
 371         struct imx_lcdc *lcdc = arg;
 372         struct drm_crtc *crtc = &lcdc->pipe.crtc;
 373         unsigned int status;
 374
 375         status = readl(lcdc->base + IMX21LCDC_LISR);
 376
 377         if (status & INTR_EOF) {
 378                 drm_crtc_handle_vblank(crtc);
 379                 return IRQ_HANDLED;
 380         }
 381
 382         return IRQ_NONE;
 383 }
 384
 385 static int imx_lcdc_probe(struct platform_device *pdev)
 386 {
 387         struct imx_lcdc *lcdc;
 388         struct drm_device *drm;
 389         struct drm_bridge *bridge;
 390         int irq;
 391         int ret;
 392         struct device *dev = &pdev->dev;
 393
 394         lcdc = devm_drm_dev_alloc(dev, &imx_lcdc_drm_driver,
 395                                   struct imx_lcdc, drm);
 396         if (IS_ERR(lcdc))
 397                 return PTR_ERR(lcdc);
 398
 399         drm = &lcdc->drm;
 400
 401         lcdc->base = devm_platform_ioremap_resource(pdev, 0);
 402         if (IS_ERR(lcdc->base))
 403                 return dev_err_probe(dev, PTR_ERR(lcdc->base), "Cannot get IO memory\n");
 404
 405         bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
 406         if (IS_ERR(bridge))
 407                 return dev_err_probe(dev, PTR_ERR(bridge), "Failed to find bridge\n");
 408
 409         /* Get Clocks */
 410         lcdc->clk_ipg = devm_clk_get(dev, "ipg");
 411         if (IS_ERR(lcdc->clk_ipg))
 412                 return dev_err_probe(dev, PTR_ERR(lcdc->clk_ipg), "Failed to get %s clk\n", "ipg");
 413
 414         lcdc->clk_ahb = devm_clk_get(dev, "ahb");
 415         if (IS_ERR(lcdc->clk_ahb))
 416                 return dev_err_probe(dev, PTR_ERR(lcdc->clk_ahb), "Failed to get %s clk\n", "ahb");
 417
 418         lcdc->clk_per = devm_clk_get(dev, "per");
 419         if (IS_ERR(lcdc->clk_per))
 420                 return dev_err_probe(dev, PTR_ERR(lcdc->clk_per), "Failed to get %s clk\n", "per");
 421
 422         ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32));
 423         if (ret)
 424                 return dev_err_probe(dev, ret, "Cannot set DMA Mask\n");
 425
 426         /* Modeset init */
 427         ret = drmm_mode_config_init(drm);
 428         if (ret)
 429                 return dev_err_probe(dev, ret, "Cannot initialize mode configuration structure\n");
 430
 431         /* CRTC, Plane, Encoder */
 432         ret = drm_simple_display_pipe_init(drm, &lcdc->pipe,
 433                                            &imx_lcdc_pipe_funcs,
 434                                            imx_lcdc_formats,
 435                                            ARRAY_SIZE(imx_lcdc_formats), NULL, NULL);
 436         if (ret < 0)
 437                 return dev_err_probe(drm->dev, ret, "Cannot setup simple display pipe\n");
 438
 439         ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
 440         if (ret < 0)
 441                 return dev_err_probe(drm->dev, ret, "Failed to initialize vblank\n");
 442
 443         ret = drm_bridge_attach(&lcdc->pipe.encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 444         if (ret)
 445                 return dev_err_probe(drm->dev, ret, "Cannot attach bridge\n");
 446
 447         lcdc->connector = drm_bridge_connector_init(drm, &lcdc->pipe.encoder);
 448         if (IS_ERR(lcdc->connector))
 449                 return dev_err_probe(drm->dev, PTR_ERR(lcdc->connector), "Cannot init bridge connector\n");
 450
 451         drm_connector_attach_encoder(lcdc->connector, &lcdc->pipe.encoder);
 452
 453         /*
 454          * The LCDC controller does not have an enable bit. The
 455          * controller starts directly when the clocks are enabled.
 456          * If the clocks are enabled when the controller is not yet
 457          * programmed with proper register values (enabled at the
 458          * bootloader, for example) then it just goes into some undefined
 459          * state.
 460          * To avoid this issue, let's enable and disable LCDC IPG,
 461          * PER and AHB clock so that we force some kind of 'reset'
 462          * to the LCDC block.
 463          */
 464
 465         ret = clk_prepare_enable(lcdc->clk_ipg);
 466         if (ret)
 467                 return dev_err_probe(dev, ret, "Cannot enable ipg clock\n");
 468         clk_disable_unprepare(lcdc->clk_ipg);
 469
 470         ret = clk_prepare_enable(lcdc->clk_per);
 471         if (ret)
 472                 return dev_err_probe(dev, ret, "Cannot enable per clock\n");
 473         clk_disable_unprepare(lcdc->clk_per);
 474
 475         ret = clk_prepare_enable(lcdc->clk_ahb);
 476         if (ret)
 477                 return dev_err_probe(dev, ret, "Cannot enable ahb clock\n");
 478         clk_disable_unprepare(lcdc->clk_ahb);
 479
 480         drm->mode_config.min_width = LCDC_MIN_XRES;
 481         drm->mode_config.max_width = LCDC_MAX_XRES;
 482         drm->mode_config.min_height = LCDC_MIN_YRES;
 483         drm->mode_config.max_height = LCDC_MAX_YRES;
 484         drm->mode_config.preferred_depth = 16;
 485         drm->mode_config.funcs = &imx_lcdc_mode_config_funcs;
 486         drm->mode_config.helper_private = &imx_lcdc_mode_config_helpers;
 487
 488         drm_mode_config_reset(drm);
 489
 490         irq = platform_get_irq(pdev, 0);
 491         if (irq < 0) {
 492                 ret = irq;
 493                 return ret;
 494         }
 495
 496         ret = devm_request_irq(dev, irq, imx_lcdc_irq_handler, 0, "imx-lcdc", lcdc);
 497         if (ret < 0)
 498                 return dev_err_probe(drm->dev, ret, "Failed to install IRQ handler\n");
 499
 500         platform_set_drvdata(pdev, drm);
 501
 502         ret = drm_dev_register(&lcdc->drm, 0);
 503         if (ret)
 504                 return dev_err_probe(dev, ret, "Cannot register device\n");
 505
 506         drm_client_setup(drm, NULL);
 507
 508         return 0;
 509 }
 510
 511 static void imx_lcdc_remove(struct platform_device *pdev)
 512 {
 513         struct drm_device *drm = platform_get_drvdata(pdev);
 514
 515         drm_dev_unregister(drm);
 516         drm_atomic_helper_shutdown(drm);
 517 }
 518
 519 static void imx_lcdc_shutdown(struct platform_device *pdev)
 520 {
 521         drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
 522 }
 523
 524 static struct platform_driver imx_lcdc_driver = {
 525         .driver = {
 526                 .name = "imx-lcdc",
 527                 .of_match_table = imx_lcdc_of_dev_id,
 528         },
 529         .probe = imx_lcdc_probe,
 530         .remove_new = imx_lcdc_remove,
 531         .shutdown = imx_lcdc_shutdown,
 532 };
 533 module_platform_driver(imx_lcdc_driver);
 534
 535 MODULE_AUTHOR("Marian Cichy <[email protected]>");
 536 MODULE_DESCRIPTION("Freescale i.MX LCDC driver");
 537 MODULE_LICENSE("GPL");