1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * DRM driver for Sitronix ST7586 panels 4 * 5 * Copyright 2017 David Lechner <david@lechnology.com> 6 */ 7 8 #include <linux/delay.h> 9 #include <linux/dma-buf.h> 10 #include <linux/gpio/consumer.h> 11 #include <linux/module.h> 12 #include <linux/property.h> 13 #include <linux/spi/spi.h> 14 #include <video/mipi_display.h> 15 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_cma_helper.h> 20 #include <drm/drm_fb_helper.h> 21 #include <drm/drm_format_helper.h> 22 #include <drm/drm_gem_cma_helper.h> 23 #include <drm/drm_gem_framebuffer_helper.h> 24 #include <drm/drm_mipi_dbi.h> 25 #include <drm/drm_rect.h> 26 #include <drm/drm_vblank.h> 27 28 /* controller-specific commands */ 29 #define ST7586_DISP_MODE_GRAY 0x38 30 #define ST7586_DISP_MODE_MONO 0x39 31 #define ST7586_ENABLE_DDRAM 0x3a 32 #define ST7586_SET_DISP_DUTY 0xb0 33 #define ST7586_SET_PART_DISP 0xb4 34 #define ST7586_SET_NLINE_INV 0xb5 35 #define ST7586_SET_VOP 0xc0 36 #define ST7586_SET_BIAS_SYSTEM 0xc3 37 #define ST7586_SET_BOOST_LEVEL 0xc4 38 #define ST7586_SET_VOP_OFFSET 0xc7 39 #define ST7586_ENABLE_ANALOG 0xd0 40 #define ST7586_AUTO_READ_CTRL 0xd7 41 #define ST7586_OTP_RW_CTRL 0xe0 42 #define ST7586_OTP_CTRL_OUT 0xe1 43 #define ST7586_OTP_READ 0xe3 44 45 #define ST7586_DISP_CTRL_MX BIT(6) 46 #define ST7586_DISP_CTRL_MY BIT(7) 47 48 /* 49 * The ST7586 controller has an unusual pixel format where 2bpp grayscale is 50 * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd 51 * pixel using only 2 bits. 52 * 53 * | D7 | D6 | D5 || | || 2bpp | 54 * | (D4) | (D3) | (D2) || D1 | D0 || GRAY | 55 * +------+------+------++------+------++------+ 56 * | 1 | 1 | 1 || 1 | 1 || 0 0 | black 57 * | 1 | 0 | 0 || 1 | 0 || 0 1 | dark gray 58 * | 0 | 1 | 0 || 0 | 1 || 1 0 | light gray 59 * | 0 | 0 | 0 || 0 | 0 || 1 1 | white 60 */ 61 62 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 }; 63 64 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr, 65 struct drm_framebuffer *fb, 66 struct drm_rect *clip) 67 { 68 size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1); 69 unsigned int x, y; 70 u8 *src, *buf, val; 71 72 buf = kmalloc(len, GFP_KERNEL); 73 if (!buf) 74 return; 75 76 drm_fb_xrgb8888_to_gray8(buf, vaddr, fb, clip); 77 src = buf; 78 79 for (y = clip->y1; y < clip->y2; y++) { 80 for (x = clip->x1; x < clip->x2; x += 3) { 81 val = st7586_lookup[*src++ >> 6] << 5; 82 val |= st7586_lookup[*src++ >> 6] << 2; 83 val |= st7586_lookup[*src++ >> 6] >> 1; 84 *dst++ = val; 85 } 86 } 87 88 kfree(buf); 89 } 90 91 static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb, 92 struct drm_rect *clip) 93 { 94 struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0); 95 struct dma_buf_attachment *import_attach = cma_obj->base.import_attach; 96 void *src = cma_obj->vaddr; 97 int ret = 0; 98 99 if (import_attach) { 100 ret = dma_buf_begin_cpu_access(import_attach->dmabuf, 101 DMA_FROM_DEVICE); 102 if (ret) 103 return ret; 104 } 105 106 st7586_xrgb8888_to_gray332(dst, src, fb, clip); 107 108 if (import_attach) 109 ret = dma_buf_end_cpu_access(import_attach->dmabuf, 110 DMA_FROM_DEVICE); 111 112 return ret; 113 } 114 115 static void st7586_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) 116 { 117 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev); 118 struct mipi_dbi *dbi = &dbidev->dbi; 119 int start, end, idx, ret = 0; 120 121 if (!dbidev->enabled) 122 return; 123 124 if (!drm_dev_enter(fb->dev, &idx)) 125 return; 126 127 /* 3 pixels per byte, so grow clip to nearest multiple of 3 */ 128 rect->x1 = rounddown(rect->x1, 3); 129 rect->x2 = roundup(rect->x2, 3); 130 131 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect)); 132 133 ret = st7586_buf_copy(dbidev->tx_buf, fb, rect); 134 if (ret) 135 goto err_msg; 136 137 /* Pixels are packed 3 per byte */ 138 start = rect->x1 / 3; 139 end = rect->x2 / 3; 140 141 mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS, 142 (start >> 8) & 0xFF, start & 0xFF, 143 (end >> 8) & 0xFF, (end - 1) & 0xFF); 144 mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS, 145 (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF, 146 (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF); 147 148 ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, 149 (u8 *)dbidev->tx_buf, 150 (end - start) * (rect->y2 - rect->y1)); 151 err_msg: 152 if (ret) 153 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret); 154 155 drm_dev_exit(idx); 156 } 157 158 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe, 159 struct drm_plane_state *old_state) 160 { 161 struct drm_plane_state *state = pipe->plane.state; 162 struct drm_crtc *crtc = &pipe->crtc; 163 struct drm_rect rect; 164 165 if (drm_atomic_helper_damage_merged(old_state, state, &rect)) 166 st7586_fb_dirty(state->fb, &rect); 167 168 if (crtc->state->event) { 169 spin_lock_irq(&crtc->dev->event_lock); 170 drm_crtc_send_vblank_event(crtc, crtc->state->event); 171 spin_unlock_irq(&crtc->dev->event_lock); 172 crtc->state->event = NULL; 173 } 174 } 175 176 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe, 177 struct drm_crtc_state *crtc_state, 178 struct drm_plane_state *plane_state) 179 { 180 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 181 struct drm_framebuffer *fb = plane_state->fb; 182 struct mipi_dbi *dbi = &dbidev->dbi; 183 struct drm_rect rect = { 184 .x1 = 0, 185 .x2 = fb->width, 186 .y1 = 0, 187 .y2 = fb->height, 188 }; 189 int idx, ret; 190 u8 addr_mode; 191 192 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 193 return; 194 195 DRM_DEBUG_KMS("\n"); 196 197 ret = mipi_dbi_poweron_reset(dbidev); 198 if (ret) 199 goto out_exit; 200 201 mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f); 202 mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00); 203 204 msleep(10); 205 206 mipi_dbi_command(dbi, ST7586_OTP_READ); 207 208 msleep(20); 209 210 mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT); 211 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE); 212 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF); 213 214 msleep(50); 215 216 mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00); 217 mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00); 218 mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02); 219 mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04); 220 mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d); 221 mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00); 222 mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY); 223 mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02); 224 225 switch (dbidev->rotation) { 226 default: 227 addr_mode = 0x00; 228 break; 229 case 90: 230 addr_mode = ST7586_DISP_CTRL_MY; 231 break; 232 case 180: 233 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY; 234 break; 235 case 270: 236 addr_mode = ST7586_DISP_CTRL_MX; 237 break; 238 } 239 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode); 240 241 mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f); 242 mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0); 243 mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77); 244 mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE); 245 246 msleep(100); 247 248 dbidev->enabled = true; 249 st7586_fb_dirty(fb, &rect); 250 251 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON); 252 out_exit: 253 drm_dev_exit(idx); 254 } 255 256 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe) 257 { 258 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 259 260 /* 261 * This callback is not protected by drm_dev_enter/exit since we want to 262 * turn off the display on regular driver unload. It's highly unlikely 263 * that the underlying SPI controller is gone should this be called after 264 * unplug. 265 */ 266 267 DRM_DEBUG_KMS("\n"); 268 269 if (!dbidev->enabled) 270 return; 271 272 mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF); 273 dbidev->enabled = false; 274 } 275 276 static const u32 st7586_formats[] = { 277 DRM_FORMAT_XRGB8888, 278 }; 279 280 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = { 281 .enable = st7586_pipe_enable, 282 .disable = st7586_pipe_disable, 283 .update = st7586_pipe_update, 284 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb, 285 }; 286 287 static const struct drm_display_mode st7586_mode = { 288 DRM_SIMPLE_MODE(178, 128, 37, 27), 289 }; 290 291 DEFINE_DRM_GEM_CMA_FOPS(st7586_fops); 292 293 static struct drm_driver st7586_driver = { 294 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 295 .fops = &st7586_fops, 296 .release = mipi_dbi_release, 297 DRM_GEM_CMA_VMAP_DRIVER_OPS, 298 .debugfs_init = mipi_dbi_debugfs_init, 299 .name = "st7586", 300 .desc = "Sitronix ST7586", 301 .date = "20170801", 302 .major = 1, 303 .minor = 0, 304 }; 305 306 static const struct of_device_id st7586_of_match[] = { 307 { .compatible = "lego,ev3-lcd" }, 308 {}, 309 }; 310 MODULE_DEVICE_TABLE(of, st7586_of_match); 311 312 static const struct spi_device_id st7586_id[] = { 313 { "ev3-lcd", 0 }, 314 { }, 315 }; 316 MODULE_DEVICE_TABLE(spi, st7586_id); 317 318 static int st7586_probe(struct spi_device *spi) 319 { 320 struct device *dev = &spi->dev; 321 struct mipi_dbi_dev *dbidev; 322 struct drm_device *drm; 323 struct mipi_dbi *dbi; 324 struct gpio_desc *a0; 325 u32 rotation = 0; 326 size_t bufsize; 327 int ret; 328 329 dbidev = kzalloc(sizeof(*dbidev), GFP_KERNEL); 330 if (!dbidev) 331 return -ENOMEM; 332 333 dbi = &dbidev->dbi; 334 drm = &dbidev->drm; 335 ret = devm_drm_dev_init(dev, drm, &st7586_driver); 336 if (ret) { 337 kfree(dbidev); 338 return ret; 339 } 340 341 drm_mode_config_init(drm); 342 343 bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay; 344 345 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 346 if (IS_ERR(dbi->reset)) { 347 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n"); 348 return PTR_ERR(dbi->reset); 349 } 350 351 a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW); 352 if (IS_ERR(a0)) { 353 DRM_DEV_ERROR(dev, "Failed to get gpio 'a0'\n"); 354 return PTR_ERR(a0); 355 } 356 357 device_property_read_u32(dev, "rotation", &rotation); 358 359 ret = mipi_dbi_spi_init(spi, dbi, a0); 360 if (ret) 361 return ret; 362 363 /* Cannot read from this controller via SPI */ 364 dbi->read_commands = NULL; 365 366 ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs, 367 st7586_formats, ARRAY_SIZE(st7586_formats), 368 &st7586_mode, rotation, bufsize); 369 if (ret) 370 return ret; 371 372 /* 373 * we are using 8-bit data, so we are not actually swapping anything, 374 * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the 375 * right thing and not use 16-bit transfers (which results in swapped 376 * bytes on little-endian systems and causes out of order data to be 377 * sent to the display). 378 */ 379 dbi->swap_bytes = true; 380 381 drm_mode_config_reset(drm); 382 383 ret = drm_dev_register(drm, 0); 384 if (ret) 385 return ret; 386 387 spi_set_drvdata(spi, drm); 388 389 drm_fbdev_generic_setup(drm, 0); 390 391 return 0; 392 } 393 394 static int st7586_remove(struct spi_device *spi) 395 { 396 struct drm_device *drm = spi_get_drvdata(spi); 397 398 drm_dev_unplug(drm); 399 drm_atomic_helper_shutdown(drm); 400 401 return 0; 402 } 403 404 static void st7586_shutdown(struct spi_device *spi) 405 { 406 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 407 } 408 409 static struct spi_driver st7586_spi_driver = { 410 .driver = { 411 .name = "st7586", 412 .owner = THIS_MODULE, 413 .of_match_table = st7586_of_match, 414 }, 415 .id_table = st7586_id, 416 .probe = st7586_probe, 417 .remove = st7586_remove, 418 .shutdown = st7586_shutdown, 419 }; 420 module_spi_driver(st7586_spi_driver); 421 422 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver"); 423 MODULE_AUTHOR("David Lechner <david@lechnology.com>"); 424 MODULE_LICENSE("GPL"); 425