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_atomic_helper.h>
  21 #include <drm/drm_damage_helper.h>
  22 #include <drm/drm_drv.h>
  23 #include <drm/drm_fb_cma_helper.h>
  24 #include <drm/drm_fb_helper.h>
  25 #include <drm/drm_gem_cma_helper.h>
  26 #include <drm/drm_gem_framebuffer_helper.h>
  27 #include <drm/drm_rect.h>
  28 #include <drm/drm_vblank.h>
  29 #include <drm/tinydrm/mipi-dbi.h>
  30 #include <drm/tinydrm/tinydrm-helpers.h>
  31
  32 /* controller-specific commands */
  33 #define ST7586_DISP_MODE_GRAY   0x38
  34 #define ST7586_DISP_MODE_MONO   0x39
  35 #define ST7586_ENABLE_DDRAM     0x3a
  36 #define ST7586_SET_DISP_DUTY    0xb0
  37 #define ST7586_SET_PART_DISP    0xb4
  38 #define ST7586_SET_NLINE_INV    0xb5
  39 #define ST7586_SET_VOP          0xc0
  40 #define ST7586_SET_BIAS_SYSTEM  0xc3
  41 #define ST7586_SET_BOOST_LEVEL  0xc4
  42 #define ST7586_SET_VOP_OFFSET   0xc7
  43 #define ST7586_ENABLE_ANALOG    0xd0
  44 #define ST7586_AUTO_READ_CTRL   0xd7
  45 #define ST7586_OTP_RW_CTRL      0xe0
  46 #define ST7586_OTP_CTRL_OUT     0xe1
  47 #define ST7586_OTP_READ         0xe3
  48
  49 #define ST7586_DISP_CTRL_MX     BIT(6)
  50 #define ST7586_DISP_CTRL_MY     BIT(7)
  51
  52 /*
  53  * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
  54  * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
  55  * pixel using only 2 bits.
  56  *
  57  * |  D7  |  D6  |  D5  ||      |      || 2bpp |
  58  * | (D4) | (D3) | (D2) ||  D1  |  D0  || GRAY |
  59  * +------+------+------++------+------++------+
  60  * |  1   |  1   |  1   ||  1   |  1   || 0  0 | black
  61  * |  1   |  0   |  0   ||  1   |  0   || 0  1 | dark gray
  62  * |  0   |  1   |  0   ||  0   |  1   || 1  0 | light gray
  63  * |  0   |  0   |  0   ||  0   |  0   || 1  1 | white
  64  */
  65
  66 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
  67
  68 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
  69                                        struct drm_framebuffer *fb,
  70                                        struct drm_rect *clip)
  71 {
  72         size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
  73         unsigned int x, y;
  74         u8 *src, *buf, val;
  75
  76         buf = kmalloc(len, GFP_KERNEL);
  77         if (!buf)
  78                 return;
  79
  80         tinydrm_xrgb8888_to_gray8(buf, vaddr, fb, clip);
  81         src = buf;
  82
  83         for (y = clip->y1; y < clip->y2; y++) {
  84                 for (x = clip->x1; x < clip->x2; x += 3) {
  85                         val = st7586_lookup[*src++ >> 6] << 5;
  86                         val |= st7586_lookup[*src++ >> 6] << 2;
  87                         val |= st7586_lookup[*src++ >> 6] >> 1;
  88                         *dst++ = val;
  89                 }
  90         }
  91
  92         kfree(buf);
  93 }
  94
  95 static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb,
  96                            struct drm_rect *clip)
  97 {
  98         struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
  99         struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
 100         void *src = cma_obj->vaddr;
 101         int ret = 0;
 102
 103         if (import_attach) {
 104                 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
 105                                                DMA_FROM_DEVICE);
 106                 if (ret)
 107                         return ret;
 108         }
 109
 110         st7586_xrgb8888_to_gray332(dst, src, fb, clip);
 111
 112         if (import_attach)
 113                 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
 114                                              DMA_FROM_DEVICE);
 115
 116         return ret;
 117 }
 118
 119 static void st7586_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
 120 {
 121         struct mipi_dbi *mipi = drm_to_mipi_dbi(fb->dev);
 122         int start, end, idx, ret = 0;
 123
 124         if (!mipi->enabled)
 125                 return;
 126
 127         if (!drm_dev_enter(fb->dev, &idx))
 128                 return;
 129
 130         /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
 131         rect->x1 = rounddown(rect->x1, 3);
 132         rect->x2 = roundup(rect->x2, 3);
 133
 134         DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
 135
 136         ret = st7586_buf_copy(mipi->tx_buf, fb, rect);
 137         if (ret)
 138                 goto err_msg;
 139
 140         /* Pixels are packed 3 per byte */
 141         start = rect->x1 / 3;
 142         end = rect->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                          (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,
 149                          (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);
 150
 151         ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
 152                                    (u8 *)mipi->tx_buf,
 153                                    (end - start) * (rect->y2 - rect->y1));
 154 err_msg:
 155         if (ret)
 156                 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
 157
 158         drm_dev_exit(idx);
 159 }
 160
 161 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,
 162                                struct drm_plane_state *old_state)
 163 {
 164         struct drm_plane_state *state = pipe->plane.state;
 165         struct drm_crtc *crtc = &pipe->crtc;
 166         struct drm_rect rect;
 167
 168         if (drm_atomic_helper_damage_merged(old_state, state, &rect))
 169                 st7586_fb_dirty(state->fb, &rect);
 170
 171         if (crtc->state->event) {
 172                 spin_lock_irq(&crtc->dev->event_lock);
 173                 drm_crtc_send_vblank_event(crtc, crtc->state->event);
 174                 spin_unlock_irq(&crtc->dev->event_lock);
 175                 crtc->state->event = NULL;
 176         }
 177 }
 178
 179 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
 180                                struct drm_crtc_state *crtc_state,
 181                                struct drm_plane_state *plane_state)
 182 {
 183         struct mipi_dbi *mipi = drm_to_mipi_dbi(pipe->crtc.dev);
 184         struct drm_framebuffer *fb = plane_state->fb;
 185         struct drm_rect rect = {
 186                 .x1 = 0,
 187                 .x2 = fb->width,
 188                 .y1 = 0,
 189                 .y2 = fb->height,
 190         };
 191         int idx, ret;
 192         u8 addr_mode;
 193
 194         if (!drm_dev_enter(pipe->crtc.dev, &idx))
 195                 return;
 196
 197         DRM_DEBUG_KMS("\n");
 198
 199         ret = mipi_dbi_poweron_reset(mipi);
 200         if (ret)
 201                 goto out_exit;
 202
 203         mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
 204         mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
 205
 206         msleep(10);
 207
 208         mipi_dbi_command(mipi, ST7586_OTP_READ);
 209
 210         msleep(20);
 211
 212         mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
 213         mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
 214         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
 215
 216         msleep(50);
 217
 218         mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
 219         mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
 220         mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
 221         mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
 222         mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
 223         mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
 224         mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
 225         mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
 226
 227         switch (mipi->rotation) {
 228         default:
 229                 addr_mode = 0x00;
 230                 break;
 231         case 90:
 232                 addr_mode = ST7586_DISP_CTRL_MY;
 233                 break;
 234         case 180:
 235                 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
 236                 break;
 237         case 270:
 238                 addr_mode = ST7586_DISP_CTRL_MX;
 239                 break;
 240         }
 241         mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
 242
 243         mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
 244         mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
 245         mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
 246         mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
 247
 248         msleep(100);
 249
 250         mipi->enabled = true;
 251         st7586_fb_dirty(fb, &rect);
 252
 253         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
 254 out_exit:
 255         drm_dev_exit(idx);
 256 }
 257
 258 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
 259 {
 260         struct mipi_dbi *mipi = drm_to_mipi_dbi(pipe->crtc.dev);
 261
 262         /*
 263          * This callback is not protected by drm_dev_enter/exit since we want to
 264          * turn off the display on regular driver unload. It's highly unlikely
 265          * that the underlying SPI controller is gone should this be called after
 266          * unplug.
 267          */
 268
 269         DRM_DEBUG_KMS("\n");
 270
 271         if (!mipi->enabled)
 272                 return;
 273
 274         mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
 275         mipi->enabled = false;
 276 }
 277
 278 static const u32 st7586_formats[] = {
 279         DRM_FORMAT_XRGB8888,
 280 };
 281
 282 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
 283         .enable         = st7586_pipe_enable,
 284         .disable        = st7586_pipe_disable,
 285         .update         = st7586_pipe_update,
 286         .prepare_fb     = drm_gem_fb_simple_display_pipe_prepare_fb,
 287 };
 288
 289 static const struct drm_mode_config_funcs st7586_mode_config_funcs = {
 290         .fb_create = drm_gem_fb_create_with_dirty,
 291         .atomic_check = drm_atomic_helper_check,
 292         .atomic_commit = drm_atomic_helper_commit,
 293 };
 294
 295 static const struct drm_display_mode st7586_mode = {
 296         DRM_SIMPLE_MODE(178, 128, 37, 27),
 297 };
 298
 299 DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
 300
 301 static struct drm_driver st7586_driver = {
 302         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
 303                                   DRIVER_ATOMIC,
 304         .fops                   = &st7586_fops,
 305         .release                = mipi_dbi_release,
 306         DRM_GEM_CMA_VMAP_DRIVER_OPS,
 307         .debugfs_init           = mipi_dbi_debugfs_init,
 308         .name                   = "st7586",
 309         .desc                   = "Sitronix ST7586",
 310         .date                   = "20170801",
 311         .major                  = 1,
 312         .minor                  = 0,
 313 };
 314
 315 static const struct of_device_id st7586_of_match[] = {
 316         { .compatible = "lego,ev3-lcd" },
 317         {},
 318 };
 319 MODULE_DEVICE_TABLE(of, st7586_of_match);
 320
 321 static const struct spi_device_id st7586_id[] = {
 322         { "ev3-lcd", 0 },
 323         { },
 324 };
 325 MODULE_DEVICE_TABLE(spi, st7586_id);
 326
 327 static int st7586_probe(struct spi_device *spi)
 328 {
 329         struct device *dev = &spi->dev;
 330         struct drm_device *drm;
 331         struct mipi_dbi *mipi;
 332         struct gpio_desc *a0;
 333         u32 rotation = 0;
 334         size_t bufsize;
 335         int ret;
 336
 337         mipi = kzalloc(sizeof(*mipi), GFP_KERNEL);
 338         if (!mipi)
 339                 return -ENOMEM;
 340
 341         drm = &mipi->drm;
 342         ret = devm_drm_dev_init(dev, drm, &st7586_driver);
 343         if (ret) {
 344                 kfree(mipi);
 345                 return ret;
 346         }
 347
 348         drm_mode_config_init(drm);
 349         drm->mode_config.preferred_depth = 32;
 350         drm->mode_config.funcs = &st7586_mode_config_funcs;
 351
 352         mutex_init(&mipi->cmdlock);
 353
 354         bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay;
 355         mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
 356         if (!mipi->tx_buf)
 357                 return -ENOMEM;
 358
 359         mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 360         if (IS_ERR(mipi->reset)) {
 361                 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
 362                 return PTR_ERR(mipi->reset);
 363         }
 364
 365         a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
 366         if (IS_ERR(a0)) {
 367                 DRM_DEV_ERROR(dev, "Failed to get gpio 'a0'\n");
 368                 return PTR_ERR(a0);
 369         }
 370
 371         device_property_read_u32(dev, "rotation", &rotation);
 372         mipi->rotation = rotation;
 373
 374         ret = mipi_dbi_spi_init(spi, mipi, a0);
 375         if (ret)
 376                 return ret;
 377
 378         /* Cannot read from this controller via SPI */
 379         mipi->read_commands = NULL;
 380
 381         /*
 382          * we are using 8-bit data, so we are not actually swapping anything,
 383          * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
 384          * right thing and not use 16-bit transfers (which results in swapped
 385          * bytes on little-endian systems and causes out of order data to be
 386          * sent to the display).
 387          */
 388         mipi->swap_bytes = true;
 389
 390         ret = tinydrm_display_pipe_init(drm, &mipi->pipe, &st7586_pipe_funcs,
 391                                         DRM_MODE_CONNECTOR_VIRTUAL,
 392                                         st7586_formats, ARRAY_SIZE(st7586_formats),
 393                                         &st7586_mode, rotation);
 394         if (ret)
 395                 return ret;
 396
 397         drm_plane_enable_fb_damage_clips(&mipi->pipe.plane);
 398
 399         drm_mode_config_reset(drm);
 400
 401         ret = drm_dev_register(drm, 0);
 402         if (ret)
 403                 return ret;
 404
 405         spi_set_drvdata(spi, drm);
 406
 407         DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
 408                       drm->mode_config.preferred_depth, rotation);
 409
 410         drm_fbdev_generic_setup(drm, 32);
 411
 412         return 0;
 413 }
 414
 415 static int st7586_remove(struct spi_device *spi)
 416 {
 417         struct drm_device *drm = spi_get_drvdata(spi);
 418
 419         drm_dev_unplug(drm);
 420         drm_atomic_helper_shutdown(drm);
 421
 422         return 0;
 423 }
 424
 425 static void st7586_shutdown(struct spi_device *spi)
 426 {
 427         drm_atomic_helper_shutdown(spi_get_drvdata(spi));
 428 }
 429
 430 static struct spi_driver st7586_spi_driver = {
 431         .driver = {
 432                 .name = "st7586",
 433                 .owner = THIS_MODULE,
 434                 .of_match_table = st7586_of_match,
 435         },
 436         .id_table = st7586_id,
 437         .probe = st7586_probe,
 438         .remove = st7586_remove,
 439         .shutdown = st7586_shutdown,
 440 };
 441 module_spi_driver(st7586_spi_driver);
 442
 443 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
 444 MODULE_AUTHOR("David Lechner <david@lechnology.com>");
 445 MODULE_LICENSE("GPL");