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