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/clients/drm_client_setup.h>
  16 #include <drm/drm_atomic_helper.h>
  17 #include <drm/drm_damage_helper.h>
  18 #include <drm/drm_drv.h>
  19 #include <drm/drm_fb_dma_helper.h>
  20 #include <drm/drm_fbdev_dma.h>
  21 #include <drm/drm_format_helper.h>
  22 #include <drm/drm_framebuffer.h>
  23 #include <drm/drm_gem_atomic_helper.h>
  24 #include <drm/drm_gem_dma_helper.h>
  25 #include <drm/drm_gem_framebuffer_helper.h>
  26 #include <drm/drm_managed.h>
  27 #include <drm/drm_mipi_dbi.h>
  28 #include <drm/drm_rect.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                                        struct drm_format_conv_state *fmtcnv_state)
  70 {
  71         size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
  72         unsigned int x, y;
  73         u8 *src, *buf, val;
  74         struct iosys_map dst_map, vmap;
  75
  76         buf = kmalloc(len, GFP_KERNEL);
  77         if (!buf)
  78                 return;
  79
  80         iosys_map_set_vaddr(&dst_map, buf);
  81         iosys_map_set_vaddr(&vmap, vaddr);
  82         drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, fb, clip, fmtcnv_state);
  83         src = buf;
  84
  85         for (y = clip->y1; y < clip->y2; y++) {
  86                 for (x = clip->x1; x < clip->x2; x += 3) {
  87                         val = st7586_lookup[*src++ >> 6] << 5;
  88                         val |= st7586_lookup[*src++ >> 6] << 2;
  89                         val |= st7586_lookup[*src++ >> 6] >> 1;
  90                         *dst++ = val;
  91                 }
  92         }
  93
  94         kfree(buf);
  95 }
  96
  97 static int st7586_buf_copy(void *dst, struct iosys_map *src, struct drm_framebuffer *fb,
  98                            struct drm_rect *clip, struct drm_format_conv_state *fmtcnv_state)
  99 {
 100         int ret;
 101
 102         ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
 103         if (ret)
 104                 return ret;
 105
 106         st7586_xrgb8888_to_gray332(dst, src->vaddr, fb, clip, fmtcnv_state);
 107
 108         drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 109
 110         return 0;
 111 }
 112
 113 static void st7586_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,
 114                             struct drm_rect *rect, struct drm_format_conv_state *fmtcnv_state)
 115 {
 116         struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
 117         struct mipi_dbi *dbi = &dbidev->dbi;
 118         int start, end, ret = 0;
 119
 120         /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
 121         rect->x1 = rounddown(rect->x1, 3);
 122         rect->x2 = roundup(rect->x2, 3);
 123
 124         DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
 125
 126         ret = st7586_buf_copy(dbidev->tx_buf, src, fb, rect, fmtcnv_state);
 127         if (ret)
 128                 goto err_msg;
 129
 130         /* Pixels are packed 3 per byte */
 131         start = rect->x1 / 3;
 132         end = rect->x2 / 3;
 133
 134         mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,
 135                          (start >> 8) & 0xFF, start & 0xFF,
 136                          (end >> 8) & 0xFF, (end - 1) & 0xFF);
 137         mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS,
 138                          (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,
 139                          (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);
 140
 141         ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START,
 142                                    (u8 *)dbidev->tx_buf,
 143                                    (end - start) * (rect->y2 - rect->y1));
 144 err_msg:
 145         if (ret)
 146                 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
 147 }
 148
 149 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,
 150                                struct drm_plane_state *old_state)
 151 {
 152         struct drm_plane_state *state = pipe->plane.state;
 153         struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
 154         struct drm_framebuffer *fb = state->fb;
 155         struct drm_rect rect;
 156         int idx;
 157
 158         if (!pipe->crtc.state->active)
 159                 return;
 160
 161         if (!drm_dev_enter(fb->dev, &idx))
 162                 return;
 163
 164         if (drm_atomic_helper_damage_merged(old_state, state, &rect))
 165                 st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
 166                                 &shadow_plane_state->fmtcnv_state);
 167
 168         drm_dev_exit(idx);
 169 }
 170
 171 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
 172                                struct drm_crtc_state *crtc_state,
 173                                struct drm_plane_state *plane_state)
 174 {
 175         struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
 176         struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
 177         struct drm_framebuffer *fb = plane_state->fb;
 178         struct mipi_dbi *dbi = &dbidev->dbi;
 179         struct drm_rect rect = {
 180                 .x1 = 0,
 181                 .x2 = fb->width,
 182                 .y1 = 0,
 183                 .y2 = fb->height,
 184         };
 185         int idx, ret;
 186         u8 addr_mode;
 187
 188         if (!drm_dev_enter(pipe->crtc.dev, &idx))
 189                 return;
 190
 191         DRM_DEBUG_KMS("\n");
 192
 193         ret = mipi_dbi_poweron_reset(dbidev);
 194         if (ret)
 195                 goto out_exit;
 196
 197         mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f);
 198         mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00);
 199
 200         msleep(10);
 201
 202         mipi_dbi_command(dbi, ST7586_OTP_READ);
 203
 204         msleep(20);
 205
 206         mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT);
 207         mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
 208         mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
 209
 210         msleep(50);
 211
 212         mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00);
 213         mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00);
 214         mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02);
 215         mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04);
 216         mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d);
 217         mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00);
 218         mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY);
 219         mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02);
 220
 221         switch (dbidev->rotation) {
 222         default:
 223                 addr_mode = 0x00;
 224                 break;
 225         case 90:
 226                 addr_mode = ST7586_DISP_CTRL_MY;
 227                 break;
 228         case 180:
 229                 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
 230                 break;
 231         case 270:
 232                 addr_mode = ST7586_DISP_CTRL_MX;
 233                 break;
 234         }
 235         mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
 236
 237         mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f);
 238         mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0);
 239         mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77);
 240         mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
 241
 242         msleep(100);
 243
 244         st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
 245                         &shadow_plane_state->fmtcnv_state);
 246
 247         mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
 248 out_exit:
 249         drm_dev_exit(idx);
 250 }
 251
 252 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
 253 {
 254         struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
 255
 256         /*
 257          * This callback is not protected by drm_dev_enter/exit since we want to
 258          * turn off the display on regular driver unload. It's highly unlikely
 259          * that the underlying SPI controller is gone should this be called after
 260          * unplug.
 261          */
 262
 263         DRM_DEBUG_KMS("\n");
 264
 265         mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF);
 266 }
 267
 268 static const u32 st7586_formats[] = {
 269         DRM_FORMAT_XRGB8888,
 270 };
 271
 272 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
 273         .mode_valid     = mipi_dbi_pipe_mode_valid,
 274         .enable         = st7586_pipe_enable,
 275         .disable        = st7586_pipe_disable,
 276         .update         = st7586_pipe_update,
 277         .begin_fb_access = mipi_dbi_pipe_begin_fb_access,
 278         .end_fb_access  = mipi_dbi_pipe_end_fb_access,
 279         .reset_plane    = mipi_dbi_pipe_reset_plane,
 280         .duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,
 281         .destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,
 282 };
 283
 284 static const struct drm_display_mode st7586_mode = {
 285         DRM_SIMPLE_MODE(178, 128, 37, 27),
 286 };
 287
 288 DEFINE_DRM_GEM_DMA_FOPS(st7586_fops);
 289
 290 static const struct drm_driver st7586_driver = {
 291         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
 292         .fops                   = &st7586_fops,
 293         DRM_GEM_DMA_DRIVER_OPS_VMAP,
 294         DRM_FBDEV_DMA_DRIVER_OPS,
 295         .debugfs_init           = mipi_dbi_debugfs_init,
 296         .name                   = "st7586",
 297         .desc                   = "Sitronix ST7586",
 298         .major                  = 1,
 299         .minor                  = 0,
 300 };
 301
 302 static const struct of_device_id st7586_of_match[] = {
 303         { .compatible = "lego,ev3-lcd" },
 304         {},
 305 };
 306 MODULE_DEVICE_TABLE(of, st7586_of_match);
 307
 308 static const struct spi_device_id st7586_id[] = {
 309         { "ev3-lcd", 0 },
 310         { },
 311 };
 312 MODULE_DEVICE_TABLE(spi, st7586_id);
 313
 314 static int st7586_probe(struct spi_device *spi)
 315 {
 316         struct device *dev = &spi->dev;
 317         struct mipi_dbi_dev *dbidev;
 318         struct drm_device *drm;
 319         struct mipi_dbi *dbi;
 320         struct gpio_desc *a0;
 321         u32 rotation = 0;
 322         size_t bufsize;
 323         int ret;
 324
 325         dbidev = devm_drm_dev_alloc(dev, &st7586_driver,
 326                                     struct mipi_dbi_dev, drm);
 327         if (IS_ERR(dbidev))
 328                 return PTR_ERR(dbidev);
 329
 330         dbi = &dbidev->dbi;
 331         drm = &dbidev->drm;
 332
 333         bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay;
 334
 335         dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 336         if (IS_ERR(dbi->reset))
 337                 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
 338
 339         a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
 340         if (IS_ERR(a0))
 341                 return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n");
 342
 343         device_property_read_u32(dev, "rotation", &rotation);
 344
 345         ret = mipi_dbi_spi_init(spi, dbi, a0);
 346         if (ret)
 347                 return ret;
 348
 349         /* Cannot read from this controller via SPI */
 350         dbi->read_commands = NULL;
 351
 352         ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs,
 353                                              st7586_formats, ARRAY_SIZE(st7586_formats),
 354                                              &st7586_mode, rotation, bufsize);
 355         if (ret)
 356                 return ret;
 357
 358         /*
 359          * we are using 8-bit data, so we are not actually swapping anything,
 360          * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
 361          * right thing and not use 16-bit transfers (which results in swapped
 362          * bytes on little-endian systems and causes out of order data to be
 363          * sent to the display).
 364          */
 365         dbi->swap_bytes = true;
 366
 367         drm_mode_config_reset(drm);
 368
 369         ret = drm_dev_register(drm, 0);
 370         if (ret)
 371                 return ret;
 372
 373         spi_set_drvdata(spi, drm);
 374
 375         drm_client_setup(drm, NULL);
 376
 377         return 0;
 378 }
 379
 380 static void st7586_remove(struct spi_device *spi)
 381 {
 382         struct drm_device *drm = spi_get_drvdata(spi);
 383
 384         drm_dev_unplug(drm);
 385         drm_atomic_helper_shutdown(drm);
 386 }
 387
 388 static void st7586_shutdown(struct spi_device *spi)
 389 {
 390         drm_atomic_helper_shutdown(spi_get_drvdata(spi));
 391 }
 392
 393 static struct spi_driver st7586_spi_driver = {
 394         .driver = {
 395                 .name = "st7586",
 396                 .of_match_table = st7586_of_match,
 397         },
 398         .id_table = st7586_id,
 399         .probe = st7586_probe,
 400         .remove = st7586_remove,
 401         .shutdown = st7586_shutdown,
 402 };
 403 module_spi_driver(st7586_spi_driver);
 404
 405 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
 406 MODULE_AUTHOR("David Lechner <[email protected]>");
 407 MODULE_LICENSE("GPL");