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         if (!mipi->enabled)
 124                 return 0;
 125
 126         tinydrm_merge_clips(&clip, clips, num_clips, flags, fb->width,
 127                             fb->height);
 128
 129         /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
 130         clip.x1 = rounddown(clip.x1, 3);
 131         clip.x2 = roundup(clip.x2, 3);
 132
 133         DRM_DEBUG("Flushing [FB:%d] x1=%u, x2=%u, y1=%u, y2=%u\n", fb->base.id,
 134                   clip.x1, clip.x2, clip.y1, clip.y2);
 135
 136         ret = st7586_buf_copy(mipi->tx_buf, fb, &clip);
 137         if (ret)
 138                 return ret;
 139
 140         /* Pixels are packed 3 per byte */
 141         start = clip.x1 / 3;
 142         end = clip.x2 / 3;
 143
 144         mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
 145                          (start >> 8) & 0xFF, start & 0xFF,
 146                          (end >> 8) & 0xFF, (end - 1) & 0xFF);
 147         mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS,
 148                          (clip.y1 >> 8) & 0xFF, clip.y1 & 0xFF,
 149                          (clip.y2 >> 8) & 0xFF, (clip.y2 - 1) & 0xFF);
 150
 151         ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
 152                                    (u8 *)mipi->tx_buf,
 153                                    (end - start) * (clip.y2 - clip.y1));
 154
 155         return ret;
 156 }
 157
 158 static const struct drm_framebuffer_funcs st7586_fb_funcs = {
 159         .destroy        = drm_gem_fb_destroy,
 160         .create_handle  = drm_gem_fb_create_handle,
 161         .dirty          = tinydrm_fb_dirty,
 162 };
 163
 164 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
 165                                struct drm_crtc_state *crtc_state,
 166                                struct drm_plane_state *plane_state)
 167 {
 168         struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
 169         struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
 170         int ret;
 171         u8 addr_mode;
 172
 173         DRM_DEBUG_KMS("\n");
 174
 175         ret = mipi_dbi_poweron_reset(mipi);
 176         if (ret)
 177                 return;
 178
 179         mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
 180         mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
 181
 182         msleep(10);
 183
 184         mipi_dbi_command(mipi, ST7586_OTP_READ);
 185
 186         msleep(20);
 187
 188         mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
 189         mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
 190         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
 191
 192         msleep(50);
 193
 194         mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
 195         mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
 196         mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
 197         mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
 198         mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
 199         mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
 200         mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
 201         mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
 202
 203         switch (mipi->rotation) {
 204         default:
 205                 addr_mode = 0x00;
 206                 break;
 207         case 90:
 208                 addr_mode = ST7586_DISP_CTRL_MY;
 209                 break;
 210         case 180:
 211                 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
 212                 break;
 213         case 270:
 214                 addr_mode = ST7586_DISP_CTRL_MX;
 215                 break;
 216         }
 217         mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
 218
 219         mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
 220         mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
 221         mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
 222         mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
 223
 224         msleep(100);
 225
 226         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
 227
 228         mipi_dbi_enable_flush(mipi, crtc_state, plane_state);
 229 }
 230
 231 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
 232 {
 233         struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
 234         struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
 235
 236         DRM_DEBUG_KMS("\n");
 237
 238         if (!mipi->enabled)
 239                 return;
 240
 241         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
 242         mipi->enabled = false;
 243 }
 244
 245 static const u32 st7586_formats[] = {
 246         DRM_FORMAT_XRGB8888,
 247 };
 248
 249 static int st7586_init(struct device *dev, struct mipi_dbi *mipi,
 250                 const struct drm_simple_display_pipe_funcs *pipe_funcs,
 251                 struct drm_driver *driver, const struct drm_display_mode *mode,
 252                 unsigned int rotation)
 253 {
 254         size_t bufsize = (mode->vdisplay + 2) / 3 * mode->hdisplay;
 255         struct tinydrm_device *tdev = &mipi->tinydrm;
 256         int ret;
 257
 258         mutex_init(&mipi->cmdlock);
 259
 260         mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
 261         if (!mipi->tx_buf)
 262                 return -ENOMEM;
 263
 264         ret = devm_tinydrm_init(dev, tdev, &st7586_fb_funcs, driver);
 265         if (ret)
 266                 return ret;
 267
 268         tdev->fb_dirty = st7586_fb_dirty;
 269
 270         ret = tinydrm_display_pipe_init(tdev, pipe_funcs,
 271                                         DRM_MODE_CONNECTOR_VIRTUAL,
 272                                         st7586_formats,
 273                                         ARRAY_SIZE(st7586_formats),
 274                                         mode, rotation);
 275         if (ret)
 276                 return ret;
 277
 278         tdev->drm->mode_config.preferred_depth = 32;
 279         mipi->rotation = rotation;
 280
 281         drm_mode_config_reset(tdev->drm);
 282
 283         DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
 284                       tdev->drm->mode_config.preferred_depth, rotation);
 285
 286         return 0;
 287 }
 288
 289 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
 290         .enable         = st7586_pipe_enable,
 291         .disable        = st7586_pipe_disable,
 292         .update         = tinydrm_display_pipe_update,
 293         .prepare_fb     = drm_gem_fb_simple_display_pipe_prepare_fb,
 294 };
 295
 296 static const struct drm_display_mode st7586_mode = {
 297         TINYDRM_MODE(178, 128, 37, 27),
 298 };
 299
 300 DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
 301
 302 static struct drm_driver st7586_driver = {
 303         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
 304                                   DRIVER_ATOMIC,
 305         .fops                   = &st7586_fops,
 306         TINYDRM_GEM_DRIVER_OPS,
 307         .lastclose              = drm_fb_helper_lastclose,
 308         .debugfs_init           = mipi_dbi_debugfs_init,
 309         .name                   = "st7586",
 310         .desc                   = "Sitronix ST7586",
 311         .date                   = "20170801",
 312         .major                  = 1,
 313         .minor                  = 0,
 314 };
 315
 316 static const struct of_device_id st7586_of_match[] = {
 317         { .compatible = "lego,ev3-lcd" },
 318         {},
 319 };
 320 MODULE_DEVICE_TABLE(of, st7586_of_match);
 321
 322 static const struct spi_device_id st7586_id[] = {
 323         { "ev3-lcd", 0 },
 324         { },
 325 };
 326 MODULE_DEVICE_TABLE(spi, st7586_id);
 327
 328 static int st7586_probe(struct spi_device *spi)
 329 {
 330         struct device *dev = &spi->dev;
 331         struct mipi_dbi *mipi;
 332         struct gpio_desc *a0;
 333         u32 rotation = 0;
 334         int ret;
 335
 336         mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
 337         if (!mipi)
 338                 return -ENOMEM;
 339
 340         mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 341         if (IS_ERR(mipi->reset)) {
 342                 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
 343                 return PTR_ERR(mipi->reset);
 344         }
 345
 346         a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
 347         if (IS_ERR(a0)) {
 348                 DRM_DEV_ERROR(dev, "Failed to get gpio 'a0'\n");
 349                 return PTR_ERR(a0);
 350         }
 351
 352         device_property_read_u32(dev, "rotation", &rotation);
 353
 354         ret = mipi_dbi_spi_init(spi, mipi, a0);
 355         if (ret)
 356                 return ret;
 357
 358         /* Cannot read from this controller via SPI */
 359         mipi->read_commands = NULL;
 360
 361         /*
 362          * we are using 8-bit data, so we are not actually swapping anything,
 363          * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
 364          * right thing and not use 16-bit transfers (which results in swapped
 365          * bytes on little-endian systems and causes out of order data to be
 366          * sent to the display).
 367          */
 368         mipi->swap_bytes = true;
 369
 370         ret = st7586_init(&spi->dev, mipi, &st7586_pipe_funcs, &st7586_driver,
 371                           &st7586_mode, rotation);
 372         if (ret)
 373                 return ret;
 374
 375         spi_set_drvdata(spi, mipi);
 376
 377         return devm_tinydrm_register(&mipi->tinydrm);
 378 }
 379
 380 static void st7586_shutdown(struct spi_device *spi)
 381 {
 382         struct mipi_dbi *mipi = spi_get_drvdata(spi);
 383
 384         tinydrm_shutdown(&mipi->tinydrm);
 385 }
 386
 387 static struct spi_driver st7586_spi_driver = {
 388         .driver = {
 389                 .name = "st7586",
 390                 .owner = THIS_MODULE,
 391                 .of_match_table = st7586_of_match,
 392         },
 393         .id_table = st7586_id,
 394         .probe = st7586_probe,
 395         .shutdown = st7586_shutdown,
 396 };
 397 module_spi_driver(st7586_spi_driver);
 398
 399 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
 400 MODULE_AUTHOR("David Lechner <david@lechnology.com>");
 401 MODULE_LICENSE("GPL");