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