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