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_fb_helper.h>
  21 #include <drm/drm_gem_framebuffer_helper.h>
  22 #include <drm/tinydrm/mipi-dbi.h>
  23 #include <drm/tinydrm/tinydrm-helpers.h>
  24
  25 /* controller-specific commands */
  26 #define ST7586_DISP_MODE_GRAY   0x38
  27 #define ST7586_DISP_MODE_MONO   0x39
  28 #define ST7586_ENABLE_DDRAM     0x3a
  29 #define ST7586_SET_DISP_DUTY    0xb0
  30 #define ST7586_SET_PART_DISP    0xb4
  31 #define ST7586_SET_NLINE_INV    0xb5
  32 #define ST7586_SET_VOP          0xc0
  33 #define ST7586_SET_BIAS_SYSTEM  0xc3
  34 #define ST7586_SET_BOOST_LEVEL  0xc4
  35 #define ST7586_SET_VOP_OFFSET   0xc7
  36 #define ST7586_ENABLE_ANALOG    0xd0
  37 #define ST7586_AUTO_READ_CTRL   0xd7
  38 #define ST7586_OTP_RW_CTRL      0xe0
  39 #define ST7586_OTP_CTRL_OUT     0xe1
  40 #define ST7586_OTP_READ         0xe3
  41
  42 #define ST7586_DISP_CTRL_MX     BIT(6)
  43 #define ST7586_DISP_CTRL_MY     BIT(7)
  44
  45 /*
  46  * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
  47  * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
  48  * pixel using only 2 bits.
  49  *
  50  * |  D7  |  D6  |  D5  ||      |      || 2bpp |
  51  * | (D4) | (D3) | (D2) ||  D1  |  D0  || GRAY |
  52  * +------+------+------++------+------++------+
  53  * |  1   |  1   |  1   ||  1   |  1   || 0  0 | black
  54  * |  1   |  0   |  0   ||  1   |  0   || 0  1 | dark gray
  55  * |  0   |  1   |  0   ||  0   |  1   || 1  0 | light gray
  56  * |  0   |  0   |  0   ||  0   |  0   || 1  1 | white
  57  */
  58
  59 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
  60
  61 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
  62                                        struct drm_framebuffer *fb,
  63                                        struct drm_clip_rect *clip)
  64 {
  65         size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
  66         unsigned int x, y;
  67         u8 *src, *buf, val;
  68
  69         buf = kmalloc(len, GFP_KERNEL);
  70         if (!buf)
  71                 return;
  72
  73         tinydrm_xrgb8888_to_gray8(buf, vaddr, fb, clip);
  74         src = buf;
  75
  76         for (y = clip->y1; y < clip->y2; y++) {
  77                 for (x = clip->x1; x < clip->x2; x += 3) {
  78                         val = st7586_lookup[*src++ >> 6] << 5;
  79                         val |= st7586_lookup[*src++ >> 6] << 2;
  80                         val |= st7586_lookup[*src++ >> 6] >> 1;
  81                         *dst++ = val;
  82                 }
  83         }
  84
  85         kfree(buf);
  86 }
  87
  88 static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb,
  89                            struct drm_clip_rect *clip)
  90 {
  91         struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
  92         struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
  93         void *src = cma_obj->vaddr;
  94         int ret = 0;
  95
  96         if (import_attach) {
  97                 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
  98                                                DMA_FROM_DEVICE);
  99                 if (ret)
 100                         return ret;
 101         }
 102
 103         st7586_xrgb8888_to_gray332(dst, src, fb, clip);
 104
 105         if (import_attach)
 106                 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
 107                                              DMA_FROM_DEVICE);
 108
 109         return ret;
 110 }
 111
 112 static int st7586_fb_dirty(struct drm_framebuffer *fb,
 113                            struct drm_file *file_priv, unsigned int flags,
 114                            unsigned int color, struct drm_clip_rect *clips,
 115                            unsigned int num_clips)
 116 {
 117         struct tinydrm_device *tdev = fb->dev->dev_private;
 118         struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
 119         struct drm_clip_rect clip;
 120         int start, end;
 121         int ret = 0;
 122
 123         mutex_lock(&tdev->dirty_lock);
 124
 125         if (!mipi->enabled)
 126                 goto out_unlock;
 127
 128         /* fbdev can flush even when we're not interested */
 129         if (tdev->pipe.plane.fb != fb)
 130                 goto out_unlock;
 131
 132         tinydrm_merge_clips(&clip, clips, num_clips, flags, fb->width,
 133                             fb->height);
 134
 135         /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
 136         clip.x1 = rounddown(clip.x1, 3);
 137         clip.x2 = roundup(clip.x2, 3);
 138
 139         DRM_DEBUG("Flushing [FB:%d] x1=%u, x2=%u, y1=%u, y2=%u\n", fb->base.id,
 140                   clip.x1, clip.x2, clip.y1, clip.y2);
 141
 142         ret = st7586_buf_copy(mipi->tx_buf, fb, &clip);
 143         if (ret)
 144                 goto out_unlock;
 145
 146         /* Pixels are packed 3 per byte */
 147         start = clip.x1 / 3;
 148         end = clip.x2 / 3;
 149
 150         mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
 151                          (start >> 8) & 0xFF, start & 0xFF,
 152                          (end >> 8) & 0xFF, (end - 1) & 0xFF);
 153         mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS,
 154                          (clip.y1 >> 8) & 0xFF, clip.y1 & 0xFF,
 155                          (clip.y2 >> 8) & 0xFF, (clip.y2 - 1) & 0xFF);
 156
 157         ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
 158                                    (u8 *)mipi->tx_buf,
 159                                    (end - start) * (clip.y2 - clip.y1));
 160
 161 out_unlock:
 162         mutex_unlock(&tdev->dirty_lock);
 163
 164         if (ret)
 165                 dev_err_once(fb->dev->dev, "Failed to update display %d\n",
 166                              ret);
 167
 168         return ret;
 169 }
 170
 171 static const struct drm_framebuffer_funcs st7586_fb_funcs = {
 172         .destroy        = drm_gem_fb_destroy,
 173         .create_handle  = drm_gem_fb_create_handle,
 174         .dirty          = st7586_fb_dirty,
 175 };
 176
 177 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
 178                                struct drm_crtc_state *crtc_state)
 179 {
 180         struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
 181         struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
 182         struct drm_framebuffer *fb = pipe->plane.fb;
 183         struct device *dev = tdev->drm->dev;
 184         int ret;
 185         u8 addr_mode;
 186
 187         DRM_DEBUG_KMS("\n");
 188
 189         mipi_dbi_hw_reset(mipi);
 190         ret = mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
 191         if (ret) {
 192                 DRM_DEV_ERROR(dev, "Error sending command %d\n", ret);
 193                 return;
 194         }
 195
 196         mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
 197
 198         msleep(10);
 199
 200         mipi_dbi_command(mipi, ST7586_OTP_READ);
 201
 202         msleep(20);
 203
 204         mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
 205         mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
 206         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
 207
 208         msleep(50);
 209
 210         mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
 211         mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
 212         mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
 213         mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
 214         mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
 215         mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
 216         mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
 217         mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
 218
 219         switch (mipi->rotation) {
 220         default:
 221                 addr_mode = 0x00;
 222                 break;
 223         case 90:
 224                 addr_mode = ST7586_DISP_CTRL_MY;
 225                 break;
 226         case 180:
 227                 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
 228                 break;
 229         case 270:
 230                 addr_mode = ST7586_DISP_CTRL_MX;
 231                 break;
 232         }
 233         mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
 234
 235         mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
 236         mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
 237         mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
 238         mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
 239
 240         msleep(100);
 241
 242         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
 243
 244         mipi->enabled = true;
 245
 246         if (fb)
 247                 fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0);
 248 }
 249
 250 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
 251 {
 252         struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
 253         struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
 254
 255         DRM_DEBUG_KMS("\n");
 256
 257         if (!mipi->enabled)
 258                 return;
 259
 260         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
 261         mipi->enabled = false;
 262 }
 263
 264 static const u32 st7586_formats[] = {
 265         DRM_FORMAT_XRGB8888,
 266 };
 267
 268 static int st7586_init(struct device *dev, struct mipi_dbi *mipi,
 269                 const struct drm_simple_display_pipe_funcs *pipe_funcs,
 270                 struct drm_driver *driver, const struct drm_display_mode *mode,
 271                 unsigned int rotation)
 272 {
 273         size_t bufsize = (mode->vdisplay + 2) / 3 * mode->hdisplay;
 274         struct tinydrm_device *tdev = &mipi->tinydrm;
 275         int ret;
 276
 277         mutex_init(&mipi->cmdlock);
 278
 279         mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
 280         if (!mipi->tx_buf)
 281                 return -ENOMEM;
 282
 283         ret = devm_tinydrm_init(dev, tdev, &st7586_fb_funcs, driver);
 284         if (ret)
 285                 return ret;
 286
 287         ret = tinydrm_display_pipe_init(tdev, pipe_funcs,
 288                                         DRM_MODE_CONNECTOR_VIRTUAL,
 289                                         st7586_formats,
 290                                         ARRAY_SIZE(st7586_formats),
 291                                         mode, rotation);
 292         if (ret)
 293                 return ret;
 294
 295         tdev->drm->mode_config.preferred_depth = 32;
 296         mipi->rotation = rotation;
 297
 298         drm_mode_config_reset(tdev->drm);
 299
 300         DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
 301                       tdev->drm->mode_config.preferred_depth, rotation);
 302
 303         return 0;
 304 }
 305
 306 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
 307         .enable         = st7586_pipe_enable,
 308         .disable        = st7586_pipe_disable,
 309         .update         = tinydrm_display_pipe_update,
 310         .prepare_fb     = tinydrm_display_pipe_prepare_fb,
 311 };
 312
 313 static const struct drm_display_mode st7586_mode = {
 314         TINYDRM_MODE(178, 128, 37, 27),
 315 };
 316
 317 DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
 318
 319 static struct drm_driver st7586_driver = {
 320         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
 321                                   DRIVER_ATOMIC,
 322         .fops                   = &st7586_fops,
 323         TINYDRM_GEM_DRIVER_OPS,
 324         .lastclose              = drm_fb_helper_lastclose,
 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");