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_dma.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                                        struct drm_format_conv_state *fmtcnv_state)
  69 {
  70         size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
  71         unsigned int x, y;
  72         u8 *src, *buf, val;
  73         struct iosys_map dst_map, vmap;
  74
  75         buf = kmalloc(len, GFP_KERNEL);
  76         if (!buf)
  77                 return;
  78
  79         iosys_map_set_vaddr(&dst_map, buf);
  80         iosys_map_set_vaddr(&vmap, vaddr);
  81         drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, fb, clip, fmtcnv_state);
  82         src = buf;
  83
  84         for (y = clip->y1; y < clip->y2; y++) {
  85                 for (x = clip->x1; x < clip->x2; x += 3) {
  86                         val = st7586_lookup[*src++ >> 6] << 5;
  87                         val |= st7586_lookup[*src++ >> 6] << 2;
  88                         val |= st7586_lookup[*src++ >> 6] >> 1;
  89                         *dst++ = val;
  90                 }
  91         }
  92
  93         kfree(buf);
  94 }
  95
  96 static int st7586_buf_copy(void *dst, struct iosys_map *src, struct drm_framebuffer *fb,
  97                            struct drm_rect *clip, struct drm_format_conv_state *fmtcnv_state)
  98 {
  99         int ret;
 100
 101         ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
 102         if (ret)
 103                 return ret;
 104
 105         st7586_xrgb8888_to_gray332(dst, src->vaddr, fb, clip, fmtcnv_state);
 106
 107         drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 108
 109         return 0;
 110 }
 111
 112 static void st7586_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,
 113                             struct drm_rect *rect, struct drm_format_conv_state *fmtcnv_state)
 114 {
 115         struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
 116         struct mipi_dbi *dbi = &dbidev->dbi;
 117         int start, end, ret = 0;
 118
 119         /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
 120         rect->x1 = rounddown(rect->x1, 3);
 121         rect->x2 = roundup(rect->x2, 3);
 122
 123         DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
 124
 125         ret = st7586_buf_copy(dbidev->tx_buf, src, fb, rect, fmtcnv_state);
 126         if (ret)
 127                 goto err_msg;
 128
 129         /* Pixels are packed 3 per byte */
 130         start = rect->x1 / 3;
 131         end = rect->x2 / 3;
 132
 133         mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,
 134                          (start >> 8) & 0xFF, start & 0xFF,
 135                          (end >> 8) & 0xFF, (end - 1) & 0xFF);
 136         mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS,
 137                          (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,
 138                          (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);
 139
 140         ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START,
 141                                    (u8 *)dbidev->tx_buf,
 142                                    (end - start) * (rect->y2 - rect->y1));
 143 err_msg:
 144         if (ret)
 145                 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
 146 }
 147
 148 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,
 149                                struct drm_plane_state *old_state)
 150 {
 151         struct drm_plane_state *state = pipe->plane.state;
 152         struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
 153         struct drm_framebuffer *fb = state->fb;
 154         struct drm_rect rect;
 155         int idx;
 156
 157         if (!pipe->crtc.state->active)
 158                 return;
 159
 160         if (!drm_dev_enter(fb->dev, &idx))
 161                 return;
 162
 163         if (drm_atomic_helper_damage_merged(old_state, state, &rect))
 164                 st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
 165                                 &shadow_plane_state->fmtcnv_state);
 166
 167         drm_dev_exit(idx);
 168 }
 169
 170 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
 171                                struct drm_crtc_state *crtc_state,
 172                                struct drm_plane_state *plane_state)
 173 {
 174         struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
 175         struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
 176         struct drm_framebuffer *fb = plane_state->fb;
 177         struct mipi_dbi *dbi = &dbidev->dbi;
 178         struct drm_rect rect = {
 179                 .x1 = 0,
 180                 .x2 = fb->width,
 181                 .y1 = 0,
 182                 .y2 = fb->height,
 183         };
 184         int idx, ret;
 185         u8 addr_mode;
 186
 187         if (!drm_dev_enter(pipe->crtc.dev, &idx))
 188                 return;
 189
 190         DRM_DEBUG_KMS("\n");
 191
 192         ret = mipi_dbi_poweron_reset(dbidev);
 193         if (ret)
 194                 goto out_exit;
 195
 196         mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f);
 197         mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00);
 198
 199         msleep(10);
 200
 201         mipi_dbi_command(dbi, ST7586_OTP_READ);
 202
 203         msleep(20);
 204
 205         mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT);
 206         mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
 207         mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
 208
 209         msleep(50);
 210
 211         mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00);
 212         mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00);
 213         mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02);
 214         mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04);
 215         mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d);
 216         mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00);
 217         mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY);
 218         mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02);
 219
 220         switch (dbidev->rotation) {
 221         default:
 222                 addr_mode = 0x00;
 223                 break;
 224         case 90:
 225                 addr_mode = ST7586_DISP_CTRL_MY;
 226                 break;
 227         case 180:
 228                 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
 229                 break;
 230         case 270:
 231                 addr_mode = ST7586_DISP_CTRL_MX;
 232                 break;
 233         }
 234         mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
 235
 236         mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f);
 237         mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0);
 238         mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77);
 239         mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
 240
 241         msleep(100);
 242
 243         st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
 244                         &shadow_plane_state->fmtcnv_state);
 245
 246         mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
 247 out_exit:
 248         drm_dev_exit(idx);
 249 }
 250
 251 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
 252 {
 253         struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
 254
 255         /*
 256          * This callback is not protected by drm_dev_enter/exit since we want to
 257          * turn off the display on regular driver unload. It's highly unlikely
 258          * that the underlying SPI controller is gone should this be called after
 259          * unplug.
 260          */
 261
 262         DRM_DEBUG_KMS("\n");
 263
 264         mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF);
 265 }
 266
 267 static const u32 st7586_formats[] = {
 268         DRM_FORMAT_XRGB8888,
 269 };
 270
 271 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
 272         .mode_valid     = mipi_dbi_pipe_mode_valid,
 273         .enable         = st7586_pipe_enable,
 274         .disable        = st7586_pipe_disable,
 275         .update         = st7586_pipe_update,
 276         .begin_fb_access = mipi_dbi_pipe_begin_fb_access,
 277         .end_fb_access  = mipi_dbi_pipe_end_fb_access,
 278         .reset_plane    = mipi_dbi_pipe_reset_plane,
 279         .duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,
 280         .destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,
 281 };
 282
 283 static const struct drm_display_mode st7586_mode = {
 284         DRM_SIMPLE_MODE(178, 128, 37, 27),
 285 };
 286
 287 DEFINE_DRM_GEM_DMA_FOPS(st7586_fops);
 288
 289 static const struct drm_driver st7586_driver = {
 290         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
 291         .fops                   = &st7586_fops,
 292         DRM_GEM_DMA_DRIVER_OPS_VMAP,
 293         .debugfs_init           = mipi_dbi_debugfs_init,
 294         .name                   = "st7586",
 295         .desc                   = "Sitronix ST7586",
 296         .date                   = "20170801",
 297         .major                  = 1,
 298         .minor                  = 0,
 299 };
 300
 301 static const struct of_device_id st7586_of_match[] = {
 302         { .compatible = "lego,ev3-lcd" },
 303         {},
 304 };
 305 MODULE_DEVICE_TABLE(of, st7586_of_match);
 306
 307 static const struct spi_device_id st7586_id[] = {
 308         { "ev3-lcd", 0 },
 309         { },
 310 };
 311 MODULE_DEVICE_TABLE(spi, st7586_id);
 312
 313 static int st7586_probe(struct spi_device *spi)
 314 {
 315         struct device *dev = &spi->dev;
 316         struct mipi_dbi_dev *dbidev;
 317         struct drm_device *drm;
 318         struct mipi_dbi *dbi;
 319         struct gpio_desc *a0;
 320         u32 rotation = 0;
 321         size_t bufsize;
 322         int ret;
 323
 324         dbidev = devm_drm_dev_alloc(dev, &st7586_driver,
 325                                     struct mipi_dbi_dev, drm);
 326         if (IS_ERR(dbidev))
 327                 return PTR_ERR(dbidev);
 328
 329         dbi = &dbidev->dbi;
 330         drm = &dbidev->drm;
 331
 332         bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay;
 333
 334         dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 335         if (IS_ERR(dbi->reset))
 336                 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
 337
 338         a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
 339         if (IS_ERR(a0))
 340                 return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n");
 341
 342         device_property_read_u32(dev, "rotation", &rotation);
 343
 344         ret = mipi_dbi_spi_init(spi, dbi, a0);
 345         if (ret)
 346                 return ret;
 347
 348         /* Cannot read from this controller via SPI */
 349         dbi->read_commands = NULL;
 350
 351         ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs,
 352                                              st7586_formats, ARRAY_SIZE(st7586_formats),
 353                                              &st7586_mode, rotation, bufsize);
 354         if (ret)
 355                 return ret;
 356
 357         /*
 358          * we are using 8-bit data, so we are not actually swapping anything,
 359          * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
 360          * right thing and not use 16-bit transfers (which results in swapped
 361          * bytes on little-endian systems and causes out of order data to be
 362          * sent to the display).
 363          */
 364         dbi->swap_bytes = true;
 365
 366         drm_mode_config_reset(drm);
 367
 368         ret = drm_dev_register(drm, 0);
 369         if (ret)
 370                 return ret;
 371
 372         spi_set_drvdata(spi, drm);
 373
 374         drm_fbdev_dma_setup(drm, 0);
 375
 376         return 0;
 377 }
 378
 379 static void st7586_remove(struct spi_device *spi)
 380 {
 381         struct drm_device *drm = spi_get_drvdata(spi);
 382
 383         drm_dev_unplug(drm);
 384         drm_atomic_helper_shutdown(drm);
 385 }
 386
 387 static void st7586_shutdown(struct spi_device *spi)
 388 {
 389         drm_atomic_helper_shutdown(spi_get_drvdata(spi));
 390 }
 391
 392 static struct spi_driver st7586_spi_driver = {
 393         .driver = {
 394                 .name = "st7586",
 395                 .of_match_table = st7586_of_match,
 396         },
 397         .id_table = st7586_id,
 398         .probe = st7586_probe,
 399         .remove = st7586_remove,
 400         .shutdown = st7586_shutdown,
 401 };
 402 module_spi_driver(st7586_spi_driver);
 403
 404 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
 405 MODULE_AUTHOR("David Lechner <[email protected]>");
 406 MODULE_LICENSE("GPL");