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 <[email protected]>
   6  */
   7
   8 #include <linux/delay.h>
   9 #include <linux/gpio/consumer.h>
  10 #include <linux/module.h>
  11 #include <linux/property.h>
  12 #include <linux/spi/spi.h>
  13 #include <video/mipi_display.h>
  14
  15 #include <drm/drm_atomic_helper.h>
  16 #include <drm/drm_damage_helper.h>
  17 #include <drm/drm_drv.h>
  18 #include <drm/drm_fb_dma_helper.h>
  19 #include <drm/drm_fbdev_generic.h>
  20 #include <drm/drm_format_helper.h>
  21 #include <drm/drm_framebuffer.h>
  22 #include <drm/drm_gem_atomic_helper.h>
  23 #include <drm/drm_gem_dma_helper.h>
  24 #include <drm/drm_gem_framebuffer_helper.h>
  25 #include <drm/drm_managed.h>
  26 #include <drm/drm_mipi_dbi.h>
  27 #include <drm/drm_rect.h>
  28
  29 /* controller-specific commands */
  30 #define ST7586_DISP_MODE_GRAY   0x38
  31 #define ST7586_DISP_MODE_MONO   0x39
  32 #define ST7586_ENABLE_DDRAM     0x3a
  33 #define ST7586_SET_DISP_DUTY    0xb0
  34 #define ST7586_SET_PART_DISP    0xb4
  35 #define ST7586_SET_NLINE_INV    0xb5
  36 #define ST7586_SET_VOP          0xc0
  37 #define ST7586_SET_BIAS_SYSTEM  0xc3
  38 #define ST7586_SET_BOOST_LEVEL  0xc4
  39 #define ST7586_SET_VOP_OFFSET   0xc7
  40 #define ST7586_ENABLE_ANALOG    0xd0
  41 #define ST7586_AUTO_READ_CTRL   0xd7
  42 #define ST7586_OTP_RW_CTRL      0xe0
  43 #define ST7586_OTP_CTRL_OUT     0xe1
  44 #define ST7586_OTP_READ         0xe3
  45
  46 #define ST7586_DISP_CTRL_MX     BIT(6)
  47 #define ST7586_DISP_CTRL_MY     BIT(7)
  48
  49 /*
  50  * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
  51  * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
  52  * pixel using only 2 bits.
  53  *
  54  * |  D7  |  D6  |  D5  ||      |      || 2bpp |
  55  * | (D4) | (D3) | (D2) ||  D1  |  D0  || GRAY |
  56  * +------+------+------++------+------++------+
  57  * |  1   |  1   |  1   ||  1   |  1   || 0  0 | black
  58  * |  1   |  0   |  0   ||  1   |  0   || 0  1 | dark gray
  59  * |  0   |  1   |  0   ||  0   |  1   || 1  0 | light gray
  60  * |  0   |  0   |  0   ||  0   |  0   || 1  1 | white
  61  */
  62
  63 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
  64
  65 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
  66                                        struct drm_framebuffer *fb,
  67                                        struct drm_rect *clip)
  68 {
  69         size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
  70         unsigned int x, y;
  71         u8 *src, *buf, val;
  72         struct iosys_map dst_map, vmap;
  73
  74         buf = kmalloc(len, GFP_KERNEL);
  75         if (!buf)
  76                 return;
  77
  78         iosys_map_set_vaddr(&dst_map, buf);
  79         iosys_map_set_vaddr(&vmap, vaddr);
  80         drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, 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 iosys_map *src, struct drm_framebuffer *fb,
  96                            struct drm_rect *clip)
  97 {
  98         int ret;
  99
 100         ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
 101         if (ret)
 102                 return ret;
 103
 104         st7586_xrgb8888_to_gray332(dst, src->vaddr, fb, clip);
 105
 106         drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 107
 108         return 0;
 109 }
 110
 111 static void st7586_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,
 112                             struct drm_rect *rect)
 113 {
 114         struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
 115         struct mipi_dbi *dbi = &dbidev->dbi;
 116         int start, end, ret = 0;
 117
 118         /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
 119         rect->x1 = rounddown(rect->x1, 3);
 120         rect->x2 = roundup(rect->x2, 3);
 121
 122         DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
 123
 124         ret = st7586_buf_copy(dbidev->tx_buf, src, fb, rect);
 125         if (ret)
 126                 goto err_msg;
 127
 128         /* Pixels are packed 3 per byte */
 129         start = rect->x1 / 3;
 130         end = rect->x2 / 3;
 131
 132         mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,
 133                          (start >> 8) & 0xFF, start & 0xFF,
 134                          (end >> 8) & 0xFF, (end - 1) & 0xFF);
 135         mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS,
 136                          (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,
 137                          (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);
 138
 139         ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START,
 140                                    (u8 *)dbidev->tx_buf,
 141                                    (end - start) * (rect->y2 - rect->y1));
 142 err_msg:
 143         if (ret)
 144                 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
 145 }
 146
 147 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,
 148                                struct drm_plane_state *old_state)
 149 {
 150         struct drm_plane_state *state = pipe->plane.state;
 151         struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
 152         struct drm_framebuffer *fb = state->fb;
 153         struct drm_rect rect;
 154         int idx;
 155
 156         if (!pipe->crtc.state->active)
 157                 return;
 158
 159         if (!drm_dev_enter(fb->dev, &idx))
 160                 return;
 161
 162         if (drm_atomic_helper_damage_merged(old_state, state, &rect))
 163                 st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect);
 164
 165         drm_dev_exit(idx);
 166 }
 167
 168 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
 169                                struct drm_crtc_state *crtc_state,
 170                                struct drm_plane_state *plane_state)
 171 {
 172         struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
 173         struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
 174         struct drm_framebuffer *fb = plane_state->fb;
 175         struct mipi_dbi *dbi = &dbidev->dbi;
 176         struct drm_rect rect = {
 177                 .x1 = 0,
 178                 .x2 = fb->width,
 179                 .y1 = 0,
 180                 .y2 = fb->height,
 181         };
 182         int idx, ret;
 183         u8 addr_mode;
 184
 185         if (!drm_dev_enter(pipe->crtc.dev, &idx))
 186                 return;
 187
 188         DRM_DEBUG_KMS("\n");
 189
 190         ret = mipi_dbi_poweron_reset(dbidev);
 191         if (ret)
 192                 goto out_exit;
 193
 194         mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f);
 195         mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00);
 196
 197         msleep(10);
 198
 199         mipi_dbi_command(dbi, ST7586_OTP_READ);
 200
 201         msleep(20);
 202
 203         mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT);
 204         mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
 205         mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
 206
 207         msleep(50);
 208
 209         mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00);
 210         mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00);
 211         mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02);
 212         mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04);
 213         mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d);
 214         mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00);
 215         mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY);
 216         mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02);
 217
 218         switch (dbidev->rotation) {
 219         default:
 220                 addr_mode = 0x00;
 221                 break;
 222         case 90:
 223                 addr_mode = ST7586_DISP_CTRL_MY;
 224                 break;
 225         case 180:
 226                 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
 227                 break;
 228         case 270:
 229                 addr_mode = ST7586_DISP_CTRL_MX;
 230                 break;
 231         }
 232         mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
 233
 234         mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f);
 235         mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0);
 236         mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77);
 237         mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
 238
 239         msleep(100);
 240
 241         st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect);
 242
 243         mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
 244 out_exit:
 245         drm_dev_exit(idx);
 246 }
 247
 248 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
 249 {
 250         struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
 251
 252         /*
 253          * This callback is not protected by drm_dev_enter/exit since we want to
 254          * turn off the display on regular driver unload. It's highly unlikely
 255          * that the underlying SPI controller is gone should this be called after
 256          * unplug.
 257          */
 258
 259         DRM_DEBUG_KMS("\n");
 260
 261         mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF);
 262 }
 263
 264 static const u32 st7586_formats[] = {
 265         DRM_FORMAT_XRGB8888,
 266 };
 267
 268 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
 269         .mode_valid     = mipi_dbi_pipe_mode_valid,
 270         .enable         = st7586_pipe_enable,
 271         .disable        = st7586_pipe_disable,
 272         .update         = st7586_pipe_update,
 273         .begin_fb_access = mipi_dbi_pipe_begin_fb_access,
 274         .end_fb_access  = mipi_dbi_pipe_end_fb_access,
 275         .reset_plane    = mipi_dbi_pipe_reset_plane,
 276         .duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,
 277         .destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,
 278 };
 279
 280 static const struct drm_display_mode st7586_mode = {
 281         DRM_SIMPLE_MODE(178, 128, 37, 27),
 282 };
 283
 284 DEFINE_DRM_GEM_DMA_FOPS(st7586_fops);
 285
 286 static const struct drm_driver st7586_driver = {
 287         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
 288         .fops                   = &st7586_fops,
 289         DRM_GEM_DMA_DRIVER_OPS_VMAP,
 290         .debugfs_init           = mipi_dbi_debugfs_init,
 291         .name                   = "st7586",
 292         .desc                   = "Sitronix ST7586",
 293         .date                   = "20170801",
 294         .major                  = 1,
 295         .minor                  = 0,
 296 };
 297
 298 static const struct of_device_id st7586_of_match[] = {
 299         { .compatible = "lego,ev3-lcd" },
 300         {},
 301 };
 302 MODULE_DEVICE_TABLE(of, st7586_of_match);
 303
 304 static const struct spi_device_id st7586_id[] = {
 305         { "ev3-lcd", 0 },
 306         { },
 307 };
 308 MODULE_DEVICE_TABLE(spi, st7586_id);
 309
 310 static int st7586_probe(struct spi_device *spi)
 311 {
 312         struct device *dev = &spi->dev;
 313         struct mipi_dbi_dev *dbidev;
 314         struct drm_device *drm;
 315         struct mipi_dbi *dbi;
 316         struct gpio_desc *a0;
 317         u32 rotation = 0;
 318         size_t bufsize;
 319         int ret;
 320
 321         dbidev = devm_drm_dev_alloc(dev, &st7586_driver,
 322                                     struct mipi_dbi_dev, drm);
 323         if (IS_ERR(dbidev))
 324                 return PTR_ERR(dbidev);
 325
 326         dbi = &dbidev->dbi;
 327         drm = &dbidev->drm;
 328
 329         bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay;
 330
 331         dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 332         if (IS_ERR(dbi->reset))
 333                 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
 334
 335         a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
 336         if (IS_ERR(a0))
 337                 return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n");
 338
 339         device_property_read_u32(dev, "rotation", &rotation);
 340
 341         ret = mipi_dbi_spi_init(spi, dbi, a0);
 342         if (ret)
 343                 return ret;
 344
 345         /* Cannot read from this controller via SPI */
 346         dbi->read_commands = NULL;
 347
 348         ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs,
 349                                              st7586_formats, ARRAY_SIZE(st7586_formats),
 350                                              &st7586_mode, rotation, bufsize);
 351         if (ret)
 352                 return ret;
 353
 354         /*
 355          * we are using 8-bit data, so we are not actually swapping anything,
 356          * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
 357          * right thing and not use 16-bit transfers (which results in swapped
 358          * bytes on little-endian systems and causes out of order data to be
 359          * sent to the display).
 360          */
 361         dbi->swap_bytes = true;
 362
 363         drm_mode_config_reset(drm);
 364
 365         ret = drm_dev_register(drm, 0);
 366         if (ret)
 367                 return ret;
 368
 369         spi_set_drvdata(spi, drm);
 370
 371         drm_fbdev_generic_setup(drm, 0);
 372
 373         return 0;
 374 }
 375
 376 static void st7586_remove(struct spi_device *spi)
 377 {
 378         struct drm_device *drm = spi_get_drvdata(spi);
 379
 380         drm_dev_unplug(drm);
 381         drm_atomic_helper_shutdown(drm);
 382 }
 383
 384 static void st7586_shutdown(struct spi_device *spi)
 385 {
 386         drm_atomic_helper_shutdown(spi_get_drvdata(spi));
 387 }
 388
 389 static struct spi_driver st7586_spi_driver = {
 390         .driver = {
 391                 .name = "st7586",
 392                 .owner = THIS_MODULE,
 393                 .of_match_table = st7586_of_match,
 394         },
 395         .id_table = st7586_id,
 396         .probe = st7586_probe,
 397         .remove = st7586_remove,
 398         .shutdown = st7586_shutdown,
 399 };
 400 module_spi_driver(st7586_spi_driver);
 401
 402 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
 403 MODULE_AUTHOR("David Lechner <[email protected]>");
 404 MODULE_LICENSE("GPL");