drivers/gpu/drm/tinydrm/st7586.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * DRM driver for Sitronix ST7586 panels
   4  *
   5  * Copyright 2017 David Lechner <david@lechnology.com>
   6  */
   7
   8 #include <linux/delay.h>
   9 #include <linux/dma-buf.h>
  10 #include <linux/gpio/consumer.h>
  11 #include <linux/module.h>
  12 #include <linux/property.h>
  13 #include <linux/spi/spi.h>
  14 #include <video/mipi_display.h>
  15
  16 #include <drm/drm_atomic_helper.h>
  17 #include <drm/drm_damage_helper.h>
  18 #include <drm/drm_drv.h>
  19 #include <drm/drm_fb_cma_helper.h>
  20 #include <drm/drm_fb_helper.h>
  21 #include <drm/drm_format_helper.h>
  22 #include <drm/drm_gem_cma_helper.h>
  23 #include <drm/drm_gem_framebuffer_helper.h>
  24 #include <drm/drm_rect.h>
  25 #include <drm/drm_vblank.h>
  26 #include <drm/tinydrm/mipi-dbi.h>
  27 #include <drm/tinydrm/tinydrm-helpers.h>
  28
  29 /* controller-specific commands */
  30 #define ST7586_DISP_MODE_GRAY   0x38
  31 #define ST7586_DISP_MODE_MONO   0x39
  32 #define ST7586_ENABLE_DDRAM     0x3a
  33 #define ST7586_SET_DISP_DUTY    0xb0
  34 #define ST7586_SET_PART_DISP    0xb4
  35 #define ST7586_SET_NLINE_INV    0xb5
  36 #define ST7586_SET_VOP          0xc0
  37 #define ST7586_SET_BIAS_SYSTEM  0xc3
  38 #define ST7586_SET_BOOST_LEVEL  0xc4
  39 #define ST7586_SET_VOP_OFFSET   0xc7
  40 #define ST7586_ENABLE_ANALOG    0xd0
  41 #define ST7586_AUTO_READ_CTRL   0xd7
  42 #define ST7586_OTP_RW_CTRL      0xe0
  43 #define ST7586_OTP_CTRL_OUT     0xe1
  44 #define ST7586_OTP_READ         0xe3
  45
  46 #define ST7586_DISP_CTRL_MX     BIT(6)
  47 #define ST7586_DISP_CTRL_MY     BIT(7)
  48
  49 /*
  50  * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
  51  * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
  52  * pixel using only 2 bits.
  53  *
  54  * |  D7  |  D6  |  D5  ||      |      || 2bpp |
  55  * | (D4) | (D3) | (D2) ||  D1  |  D0  || GRAY |
  56  * +------+------+------++------+------++------+
  57  * |  1   |  1   |  1   ||  1   |  1   || 0  0 | black
  58  * |  1   |  0   |  0   ||  1   |  0   || 0  1 | dark gray
  59  * |  0   |  1   |  0   ||  0   |  1   || 1  0 | light gray
  60  * |  0   |  0   |  0   ||  0   |  0   || 1  1 | white
  61  */
  62
  63 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
  64
  65 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
  66                                        struct drm_framebuffer *fb,
  67                                        struct drm_rect *clip)
  68 {
  69         size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
  70         unsigned int x, y;
  71         u8 *src, *buf, val;
  72
  73         buf = kmalloc(len, GFP_KERNEL);
  74         if (!buf)
  75                 return;
  76
  77         drm_fb_xrgb8888_to_gray8(buf, vaddr, fb, clip);
  78         src = buf;
  79
  80         for (y = clip->y1; y < clip->y2; y++) {
  81                 for (x = clip->x1; x < clip->x2; x += 3) {
  82                         val = st7586_lookup[*src++ >> 6] << 5;
  83                         val |= st7586_lookup[*src++ >> 6] << 2;
  84                         val |= st7586_lookup[*src++ >> 6] >> 1;
  85                         *dst++ = val;
  86                 }
  87         }
  88
  89         kfree(buf);
  90 }
  91
  92 static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb,
  93                            struct drm_rect *clip)
  94 {
  95         struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
  96         struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
  97         void *src = cma_obj->vaddr;
  98         int ret = 0;
  99
 100         if (import_attach) {
 101                 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
 102                                                DMA_FROM_DEVICE);
 103                 if (ret)
 104                         return ret;
 105         }
 106
 107         st7586_xrgb8888_to_gray332(dst, src, fb, clip);
 108
 109         if (import_attach)
 110                 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
 111                                              DMA_FROM_DEVICE);
 112
 113         return ret;
 114 }
 115
 116 static void st7586_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
 117 {
 118         struct mipi_dbi *mipi = drm_to_mipi_dbi(fb->dev);
 119         int start, end, idx, ret = 0;
 120
 121         if (!mipi->enabled)
 122                 return;
 123
 124         if (!drm_dev_enter(fb->dev, &idx))
 125                 return;
 126
 127         /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
 128         rect->x1 = rounddown(rect->x1, 3);
 129         rect->x2 = roundup(rect->x2, 3);
 130
 131         DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
 132
 133         ret = st7586_buf_copy(mipi->tx_buf, fb, rect);
 134         if (ret)
 135                 goto err_msg;
 136
 137         /* Pixels are packed 3 per byte */
 138         start = rect->x1 / 3;
 139         end = rect->x2 / 3;
 140
 141         mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
 142                          (start >> 8) & 0xFF, start & 0xFF,
 143                          (end >> 8) & 0xFF, (end - 1) & 0xFF);
 144         mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS,
 145                          (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,
 146                          (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);
 147
 148         ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
 149                                    (u8 *)mipi->tx_buf,
 150                                    (end - start) * (rect->y2 - rect->y1));
 151 err_msg:
 152         if (ret)
 153                 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
 154
 155         drm_dev_exit(idx);
 156 }
 157
 158 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,
 159                                struct drm_plane_state *old_state)
 160 {
 161         struct drm_plane_state *state = pipe->plane.state;
 162         struct drm_crtc *crtc = &pipe->crtc;
 163         struct drm_rect rect;
 164
 165         if (drm_atomic_helper_damage_merged(old_state, state, &rect))
 166                 st7586_fb_dirty(state->fb, &rect);
 167
 168         if (crtc->state->event) {
 169                 spin_lock_irq(&crtc->dev->event_lock);
 170                 drm_crtc_send_vblank_event(crtc, crtc->state->event);
 171                 spin_unlock_irq(&crtc->dev->event_lock);
 172                 crtc->state->event = NULL;
 173         }
 174 }
 175
 176 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
 177                                struct drm_crtc_state *crtc_state,
 178                                struct drm_plane_state *plane_state)
 179 {
 180         struct mipi_dbi *mipi = drm_to_mipi_dbi(pipe->crtc.dev);
 181         struct drm_framebuffer *fb = plane_state->fb;
 182         struct drm_rect rect = {
 183                 .x1 = 0,
 184                 .x2 = fb->width,
 185                 .y1 = 0,
 186                 .y2 = fb->height,
 187         };
 188         int idx, ret;
 189         u8 addr_mode;
 190
 191         if (!drm_dev_enter(pipe->crtc.dev, &idx))
 192                 return;
 193
 194         DRM_DEBUG_KMS("\n");
 195
 196         ret = mipi_dbi_poweron_reset(mipi);
 197         if (ret)
 198                 goto out_exit;
 199
 200         mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
 201         mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
 202
 203         msleep(10);
 204
 205         mipi_dbi_command(mipi, ST7586_OTP_READ);
 206
 207         msleep(20);
 208
 209         mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
 210         mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
 211         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
 212
 213         msleep(50);
 214
 215         mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
 216         mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
 217         mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
 218         mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
 219         mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
 220         mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
 221         mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
 222         mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
 223
 224         switch (mipi->rotation) {
 225         default:
 226                 addr_mode = 0x00;
 227                 break;
 228         case 90:
 229                 addr_mode = ST7586_DISP_CTRL_MY;
 230                 break;
 231         case 180:
 232                 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
 233                 break;
 234         case 270:
 235                 addr_mode = ST7586_DISP_CTRL_MX;
 236                 break;
 237         }
 238         mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
 239
 240         mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
 241         mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
 242         mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
 243         mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
 244
 245         msleep(100);
 246
 247         mipi->enabled = true;
 248         st7586_fb_dirty(fb, &rect);
 249
 250         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
 251 out_exit:
 252         drm_dev_exit(idx);
 253 }
 254
 255 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
 256 {
 257         struct mipi_dbi *mipi = drm_to_mipi_dbi(pipe->crtc.dev);
 258
 259         /*
 260          * This callback is not protected by drm_dev_enter/exit since we want to
 261          * turn off the display on regular driver unload. It's highly unlikely
 262          * that the underlying SPI controller is gone should this be called after
 263          * unplug.
 264          */
 265
 266         DRM_DEBUG_KMS("\n");
 267
 268         if (!mipi->enabled)
 269                 return;
 270
 271         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
 272         mipi->enabled = false;
 273 }
 274
 275 static const u32 st7586_formats[] = {
 276         DRM_FORMAT_XRGB8888,
 277 };
 278
 279 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
 280         .enable         = st7586_pipe_enable,
 281         .disable        = st7586_pipe_disable,
 282         .update         = st7586_pipe_update,
 283         .prepare_fb     = drm_gem_fb_simple_display_pipe_prepare_fb,
 284 };
 285
 286 static const struct drm_mode_config_funcs st7586_mode_config_funcs = {
 287         .fb_create = drm_gem_fb_create_with_dirty,
 288         .atomic_check = drm_atomic_helper_check,
 289         .atomic_commit = drm_atomic_helper_commit,
 290 };
 291
 292 static const struct drm_display_mode st7586_mode = {
 293         DRM_SIMPLE_MODE(178, 128, 37, 27),
 294 };
 295
 296 DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
 297
 298 static struct drm_driver st7586_driver = {
 299         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
 300                                   DRIVER_ATOMIC,
 301         .fops                   = &st7586_fops,
 302         .release                = mipi_dbi_release,
 303         DRM_GEM_CMA_VMAP_DRIVER_OPS,
 304         .debugfs_init           = mipi_dbi_debugfs_init,
 305         .name                   = "st7586",
 306         .desc                   = "Sitronix ST7586",
 307         .date                   = "20170801",
 308         .major                  = 1,
 309         .minor                  = 0,
 310 };
 311
 312 static const struct of_device_id st7586_of_match[] = {
 313         { .compatible = "lego,ev3-lcd" },
 314         {},
 315 };
 316 MODULE_DEVICE_TABLE(of, st7586_of_match);
 317
 318 static const struct spi_device_id st7586_id[] = {
 319         { "ev3-lcd", 0 },
 320         { },
 321 };
 322 MODULE_DEVICE_TABLE(spi, st7586_id);
 323
 324 static int st7586_probe(struct spi_device *spi)
 325 {
 326         struct device *dev = &spi->dev;
 327         struct drm_device *drm;
 328         struct mipi_dbi *mipi;
 329         struct gpio_desc *a0;
 330         u32 rotation = 0;
 331         size_t bufsize;
 332         int ret;
 333
 334         mipi = kzalloc(sizeof(*mipi), GFP_KERNEL);
 335         if (!mipi)
 336                 return -ENOMEM;
 337
 338         drm = &mipi->drm;
 339         ret = devm_drm_dev_init(dev, drm, &st7586_driver);
 340         if (ret) {
 341                 kfree(mipi);
 342                 return ret;
 343         }
 344
 345         drm_mode_config_init(drm);
 346         drm->mode_config.preferred_depth = 32;
 347         drm->mode_config.funcs = &st7586_mode_config_funcs;
 348
 349         mutex_init(&mipi->cmdlock);
 350
 351         bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay;
 352         mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
 353         if (!mipi->tx_buf)
 354                 return -ENOMEM;
 355
 356         mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 357         if (IS_ERR(mipi->reset)) {
 358                 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
 359                 return PTR_ERR(mipi->reset);
 360         }
 361
 362         a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
 363         if (IS_ERR(a0)) {
 364                 DRM_DEV_ERROR(dev, "Failed to get gpio 'a0'\n");
 365                 return PTR_ERR(a0);
 366         }
 367
 368         device_property_read_u32(dev, "rotation", &rotation);
 369         mipi->rotation = rotation;
 370
 371         ret = mipi_dbi_spi_init(spi, mipi, a0);
 372         if (ret)
 373                 return ret;
 374
 375         /* Cannot read from this controller via SPI */
 376         mipi->read_commands = NULL;
 377
 378         /*
 379          * we are using 8-bit data, so we are not actually swapping anything,
 380          * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
 381          * right thing and not use 16-bit transfers (which results in swapped
 382          * bytes on little-endian systems and causes out of order data to be
 383          * sent to the display).
 384          */
 385         mipi->swap_bytes = true;
 386
 387         ret = tinydrm_display_pipe_init(drm, &mipi->pipe, &st7586_pipe_funcs,
 388                                         DRM_MODE_CONNECTOR_VIRTUAL,
 389                                         st7586_formats, ARRAY_SIZE(st7586_formats),
 390                                         &st7586_mode, rotation);
 391         if (ret)
 392                 return ret;
 393
 394         drm_plane_enable_fb_damage_clips(&mipi->pipe.plane);
 395
 396         drm_mode_config_reset(drm);
 397
 398         ret = drm_dev_register(drm, 0);
 399         if (ret)
 400                 return ret;
 401
 402         spi_set_drvdata(spi, drm);
 403
 404         DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
 405                       drm->mode_config.preferred_depth, rotation);
 406
 407         drm_fbdev_generic_setup(drm, 0);
 408
 409         return 0;
 410 }
 411
 412 static int st7586_remove(struct spi_device *spi)
 413 {
 414         struct drm_device *drm = spi_get_drvdata(spi);
 415
 416         drm_dev_unplug(drm);
 417         drm_atomic_helper_shutdown(drm);
 418
 419         return 0;
 420 }
 421
 422 static void st7586_shutdown(struct spi_device *spi)
 423 {
 424         drm_atomic_helper_shutdown(spi_get_drvdata(spi));
 425 }
 426
 427 static struct spi_driver st7586_spi_driver = {
 428         .driver = {
 429                 .name = "st7586",
 430                 .owner = THIS_MODULE,
 431                 .of_match_table = st7586_of_match,
 432         },
 433         .id_table = st7586_id,
 434         .probe = st7586_probe,
 435         .remove = st7586_remove,
 436         .shutdown = st7586_shutdown,
 437 };
 438 module_spi_driver(st7586_spi_driver);
 439
 440 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
 441 MODULE_AUTHOR("David Lechner <david@lechnology.com>");
 442 MODULE_LICENSE("GPL");