drivers/gpu/drm/tinydrm/st7586.c

   1 /*
   2  * DRM driver for Sitronix ST7586 panels
   3  *
   4  * Copyright 2017 David Lechner <david@lechnology.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/delay.h>
  13 #include <linux/dma-buf.h>
  14 #include <linux/gpio/consumer.h>
  15 #include <linux/module.h>
  16 #include <linux/property.h>
  17 #include <linux/spi/spi.h>
  18 #include <video/mipi_display.h>
  19
  20 #include <drm/drm_damage_helper.h>
  21 #include <drm/drm_drv.h>
  22 #include <drm/drm_fb_cma_helper.h>
  23 #include <drm/drm_gem_cma_helper.h>
  24 #include <drm/drm_gem_framebuffer_helper.h>
  25 #include <drm/drm_rect.h>
  26 #include <drm/drm_vblank.h>
  27 #include <drm/tinydrm/mipi-dbi.h>
  28 #include <drm/tinydrm/tinydrm-helpers.h>
  29
  30 /* controller-specific commands */
  31 #define ST7586_DISP_MODE_GRAY   0x38
  32 #define ST7586_DISP_MODE_MONO   0x39
  33 #define ST7586_ENABLE_DDRAM     0x3a
  34 #define ST7586_SET_DISP_DUTY    0xb0
  35 #define ST7586_SET_PART_DISP    0xb4
  36 #define ST7586_SET_NLINE_INV    0xb5
  37 #define ST7586_SET_VOP          0xc0
  38 #define ST7586_SET_BIAS_SYSTEM  0xc3
  39 #define ST7586_SET_BOOST_LEVEL  0xc4
  40 #define ST7586_SET_VOP_OFFSET   0xc7
  41 #define ST7586_ENABLE_ANALOG    0xd0
  42 #define ST7586_AUTO_READ_CTRL   0xd7
  43 #define ST7586_OTP_RW_CTRL      0xe0
  44 #define ST7586_OTP_CTRL_OUT     0xe1
  45 #define ST7586_OTP_READ         0xe3
  46
  47 #define ST7586_DISP_CTRL_MX     BIT(6)
  48 #define ST7586_DISP_CTRL_MY     BIT(7)
  49
  50 /*
  51  * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
  52  * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
  53  * pixel using only 2 bits.
  54  *
  55  * |  D7  |  D6  |  D5  ||      |      || 2bpp |
  56  * | (D4) | (D3) | (D2) ||  D1  |  D0  || GRAY |
  57  * +------+------+------++------+------++------+
  58  * |  1   |  1   |  1   ||  1   |  1   || 0  0 | black
  59  * |  1   |  0   |  0   ||  1   |  0   || 0  1 | dark gray
  60  * |  0   |  1   |  0   ||  0   |  1   || 1  0 | light gray
  61  * |  0   |  0   |  0   ||  0   |  0   || 1  1 | white
  62  */
  63
  64 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
  65
  66 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
  67                                        struct drm_framebuffer *fb,
  68                                        struct drm_rect *clip)
  69 {
  70         size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
  71         unsigned int x, y;
  72         u8 *src, *buf, val;
  73
  74         buf = kmalloc(len, GFP_KERNEL);
  75         if (!buf)
  76                 return;
  77
  78         tinydrm_xrgb8888_to_gray8(buf, vaddr, fb, clip);
  79         src = buf;
  80
  81         for (y = clip->y1; y < clip->y2; y++) {
  82                 for (x = clip->x1; x < clip->x2; x += 3) {
  83                         val = st7586_lookup[*src++ >> 6] << 5;
  84                         val |= st7586_lookup[*src++ >> 6] << 2;
  85                         val |= st7586_lookup[*src++ >> 6] >> 1;
  86                         *dst++ = val;
  87                 }
  88         }
  89
  90         kfree(buf);
  91 }
  92
  93 static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb,
  94                            struct drm_rect *clip)
  95 {
  96         struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
  97         struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
  98         void *src = cma_obj->vaddr;
  99         int ret = 0;
 100
 101         if (import_attach) {
 102                 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
 103                                                DMA_FROM_DEVICE);
 104                 if (ret)
 105                         return ret;
 106         }
 107
 108         st7586_xrgb8888_to_gray332(dst, src, fb, clip);
 109
 110         if (import_attach)
 111                 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
 112                                              DMA_FROM_DEVICE);
 113
 114         return ret;
 115 }
 116
 117 static void st7586_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
 118 {
 119         struct tinydrm_device *tdev = fb->dev->dev_private;
 120         struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
 121         int start, end;
 122         int ret = 0;
 123
 124         if (!mipi->enabled)
 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
 156 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,
 157                                struct drm_plane_state *old_state)
 158 {
 159         struct drm_plane_state *state = pipe->plane.state;
 160         struct drm_crtc *crtc = &pipe->crtc;
 161         struct drm_rect rect;
 162
 163         if (drm_atomic_helper_damage_merged(old_state, state, &rect))
 164                 st7586_fb_dirty(state->fb, &rect);
 165
 166         if (crtc->state->event) {
 167                 spin_lock_irq(&crtc->dev->event_lock);
 168                 drm_crtc_send_vblank_event(crtc, crtc->state->event);
 169                 spin_unlock_irq(&crtc->dev->event_lock);
 170                 crtc->state->event = NULL;
 171         }
 172 }
 173
 174 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
 175                                struct drm_crtc_state *crtc_state,
 176                                struct drm_plane_state *plane_state)
 177 {
 178         struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
 179         struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
 180         struct drm_framebuffer *fb = plane_state->fb;
 181         struct drm_rect rect = {
 182                 .x1 = 0,
 183                 .x2 = fb->width,
 184                 .y1 = 0,
 185                 .y2 = fb->height,
 186         };
 187         int ret;
 188         u8 addr_mode;
 189
 190         DRM_DEBUG_KMS("\n");
 191
 192         ret = mipi_dbi_poweron_reset(mipi);
 193         if (ret)
 194                 return;
 195
 196         mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
 197         mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
 198
 199         msleep(10);
 200
 201         mipi_dbi_command(mipi, ST7586_OTP_READ);
 202
 203         msleep(20);
 204
 205         mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
 206         mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
 207         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
 208
 209         msleep(50);
 210
 211         mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
 212         mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
 213         mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
 214         mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
 215         mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
 216         mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
 217         mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
 218         mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
 219
 220         switch (mipi->rotation) {
 221         default:
 222                 addr_mode = 0x00;
 223                 break;
 224         case 90:
 225                 addr_mode = ST7586_DISP_CTRL_MY;
 226                 break;
 227         case 180:
 228                 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
 229                 break;
 230         case 270:
 231                 addr_mode = ST7586_DISP_CTRL_MX;
 232                 break;
 233         }
 234         mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
 235
 236         mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
 237         mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
 238         mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
 239         mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
 240
 241         msleep(100);
 242
 243         mipi->enabled = true;
 244         st7586_fb_dirty(fb, &rect);
 245
 246         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
 247 }
 248
 249 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
 250 {
 251         struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
 252         struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
 253
 254         DRM_DEBUG_KMS("\n");
 255
 256         if (!mipi->enabled)
 257                 return;
 258
 259         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
 260         mipi->enabled = false;
 261 }
 262
 263 static const u32 st7586_formats[] = {
 264         DRM_FORMAT_XRGB8888,
 265 };
 266
 267 static int st7586_init(struct device *dev, struct mipi_dbi *mipi,
 268                 const struct drm_simple_display_pipe_funcs *pipe_funcs,
 269                 struct drm_driver *driver, const struct drm_display_mode *mode,
 270                 unsigned int rotation)
 271 {
 272         size_t bufsize = (mode->vdisplay + 2) / 3 * mode->hdisplay;
 273         struct tinydrm_device *tdev = &mipi->tinydrm;
 274         int ret;
 275
 276         mutex_init(&mipi->cmdlock);
 277
 278         mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
 279         if (!mipi->tx_buf)
 280                 return -ENOMEM;
 281
 282         ret = devm_tinydrm_init(dev, tdev, driver);
 283         if (ret)
 284                 return ret;
 285
 286         ret = tinydrm_display_pipe_init(tdev, pipe_funcs,
 287                                         DRM_MODE_CONNECTOR_VIRTUAL,
 288                                         st7586_formats,
 289                                         ARRAY_SIZE(st7586_formats),
 290                                         mode, rotation);
 291         if (ret)
 292                 return ret;
 293
 294         drm_plane_enable_fb_damage_clips(&tdev->pipe.plane);
 295
 296         tdev->drm->mode_config.preferred_depth = 32;
 297         mipi->rotation = rotation;
 298
 299         drm_mode_config_reset(tdev->drm);
 300
 301         DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
 302                       tdev->drm->mode_config.preferred_depth, rotation);
 303
 304         return 0;
 305 }
 306
 307 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
 308         .enable         = st7586_pipe_enable,
 309         .disable        = st7586_pipe_disable,
 310         .update         = st7586_pipe_update,
 311         .prepare_fb     = drm_gem_fb_simple_display_pipe_prepare_fb,
 312 };
 313
 314 static const struct drm_display_mode st7586_mode = {
 315         TINYDRM_MODE(178, 128, 37, 27),
 316 };
 317
 318 DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
 319
 320 static struct drm_driver st7586_driver = {
 321         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
 322                                   DRIVER_ATOMIC,
 323         .fops                   = &st7586_fops,
 324         DRM_GEM_CMA_VMAP_DRIVER_OPS,
 325         .debugfs_init           = mipi_dbi_debugfs_init,
 326         .name                   = "st7586",
 327         .desc                   = "Sitronix ST7586",
 328         .date                   = "20170801",
 329         .major                  = 1,
 330         .minor                  = 0,
 331 };
 332
 333 static const struct of_device_id st7586_of_match[] = {
 334         { .compatible = "lego,ev3-lcd" },
 335         {},
 336 };
 337 MODULE_DEVICE_TABLE(of, st7586_of_match);
 338
 339 static const struct spi_device_id st7586_id[] = {
 340         { "ev3-lcd", 0 },
 341         { },
 342 };
 343 MODULE_DEVICE_TABLE(spi, st7586_id);
 344
 345 static int st7586_probe(struct spi_device *spi)
 346 {
 347         struct device *dev = &spi->dev;
 348         struct mipi_dbi *mipi;
 349         struct gpio_desc *a0;
 350         u32 rotation = 0;
 351         int ret;
 352
 353         mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
 354         if (!mipi)
 355                 return -ENOMEM;
 356
 357         mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 358         if (IS_ERR(mipi->reset)) {
 359                 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
 360                 return PTR_ERR(mipi->reset);
 361         }
 362
 363         a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
 364         if (IS_ERR(a0)) {
 365                 DRM_DEV_ERROR(dev, "Failed to get gpio 'a0'\n");
 366                 return PTR_ERR(a0);
 367         }
 368
 369         device_property_read_u32(dev, "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 = st7586_init(&spi->dev, mipi, &st7586_pipe_funcs, &st7586_driver,
 388                           &st7586_mode, rotation);
 389         if (ret)
 390                 return ret;
 391
 392         spi_set_drvdata(spi, mipi);
 393
 394         return devm_tinydrm_register(&mipi->tinydrm);
 395 }
 396
 397 static void st7586_shutdown(struct spi_device *spi)
 398 {
 399         struct mipi_dbi *mipi = spi_get_drvdata(spi);
 400
 401         tinydrm_shutdown(&mipi->tinydrm);
 402 }
 403
 404 static struct spi_driver st7586_spi_driver = {
 405         .driver = {
 406                 .name = "st7586",
 407                 .owner = THIS_MODULE,
 408                 .of_match_table = st7586_of_match,
 409         },
 410         .id_table = st7586_id,
 411         .probe = st7586_probe,
 412         .shutdown = st7586_shutdown,
 413 };
 414 module_spi_driver(st7586_spi_driver);
 415
 416 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
 417 MODULE_AUTHOR("David Lechner <david@lechnology.com>");
 418 MODULE_LICENSE("GPL");