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_managed.h> 25 #include <drm/drm_mipi_dbi.h> 26 #include <drm/drm_rect.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 (!drm_dev_enter(fb->dev, &idx)) 122 return; 123 124 /* 3 pixels per byte, so grow clip to nearest multiple of 3 */ 125 rect->x1 = rounddown(rect->x1, 3); 126 rect->x2 = roundup(rect->x2, 3); 127 128 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect)); 129 130 ret = st7586_buf_copy(dbidev->tx_buf, fb, rect); 131 if (ret) 132 goto err_msg; 133 134 /* Pixels are packed 3 per byte */ 135 start = rect->x1 / 3; 136 end = rect->x2 / 3; 137 138 mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS, 139 (start >> 8) & 0xFF, start & 0xFF, 140 (end >> 8) & 0xFF, (end - 1) & 0xFF); 141 mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS, 142 (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF, 143 (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF); 144 145 ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, 146 (u8 *)dbidev->tx_buf, 147 (end - start) * (rect->y2 - rect->y1)); 148 err_msg: 149 if (ret) 150 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret); 151 152 drm_dev_exit(idx); 153 } 154 155 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe, 156 struct drm_plane_state *old_state) 157 { 158 struct drm_plane_state *state = pipe->plane.state; 159 struct drm_rect rect; 160 161 if (!pipe->crtc.state->active) 162 return; 163 164 if (drm_atomic_helper_damage_merged(old_state, state, &rect)) 165 st7586_fb_dirty(state->fb, &rect); 166 } 167 168 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe, 169 struct drm_crtc_state *crtc_state, 170 struct drm_plane_state *plane_state) 171 { 172 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 173 struct drm_framebuffer *fb = plane_state->fb; 174 struct mipi_dbi *dbi = &dbidev->dbi; 175 struct drm_rect rect = { 176 .x1 = 0, 177 .x2 = fb->width, 178 .y1 = 0, 179 .y2 = fb->height, 180 }; 181 int idx, ret; 182 u8 addr_mode; 183 184 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 185 return; 186 187 DRM_DEBUG_KMS("\n"); 188 189 ret = mipi_dbi_poweron_reset(dbidev); 190 if (ret) 191 goto out_exit; 192 193 mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f); 194 mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00); 195 196 msleep(10); 197 198 mipi_dbi_command(dbi, ST7586_OTP_READ); 199 200 msleep(20); 201 202 mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT); 203 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE); 204 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF); 205 206 msleep(50); 207 208 mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00); 209 mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00); 210 mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02); 211 mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04); 212 mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d); 213 mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00); 214 mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY); 215 mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02); 216 217 switch (dbidev->rotation) { 218 default: 219 addr_mode = 0x00; 220 break; 221 case 90: 222 addr_mode = ST7586_DISP_CTRL_MY; 223 break; 224 case 180: 225 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY; 226 break; 227 case 270: 228 addr_mode = ST7586_DISP_CTRL_MX; 229 break; 230 } 231 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode); 232 233 mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f); 234 mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0); 235 mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77); 236 mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE); 237 238 msleep(100); 239 240 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 mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF); 261 } 262 263 static const u32 st7586_formats[] = { 264 DRM_FORMAT_XRGB8888, 265 }; 266 267 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = { 268 .enable = st7586_pipe_enable, 269 .disable = st7586_pipe_disable, 270 .update = st7586_pipe_update, 271 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb, 272 }; 273 274 static const struct drm_display_mode st7586_mode = { 275 DRM_SIMPLE_MODE(178, 128, 37, 27), 276 }; 277 278 DEFINE_DRM_GEM_CMA_FOPS(st7586_fops); 279 280 static const struct drm_driver st7586_driver = { 281 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 282 .fops = &st7586_fops, 283 DRM_GEM_CMA_DRIVER_OPS_VMAP, 284 .debugfs_init = mipi_dbi_debugfs_init, 285 .name = "st7586", 286 .desc = "Sitronix ST7586", 287 .date = "20170801", 288 .major = 1, 289 .minor = 0, 290 }; 291 292 static const struct of_device_id st7586_of_match[] = { 293 { .compatible = "lego,ev3-lcd" }, 294 {}, 295 }; 296 MODULE_DEVICE_TABLE(of, st7586_of_match); 297 298 static const struct spi_device_id st7586_id[] = { 299 { "ev3-lcd", 0 }, 300 { }, 301 }; 302 MODULE_DEVICE_TABLE(spi, st7586_id); 303 304 static int st7586_probe(struct spi_device *spi) 305 { 306 struct device *dev = &spi->dev; 307 struct mipi_dbi_dev *dbidev; 308 struct drm_device *drm; 309 struct mipi_dbi *dbi; 310 struct gpio_desc *a0; 311 u32 rotation = 0; 312 size_t bufsize; 313 int ret; 314 315 dbidev = devm_drm_dev_alloc(dev, &st7586_driver, 316 struct mipi_dbi_dev, drm); 317 if (IS_ERR(dbidev)) 318 return PTR_ERR(dbidev); 319 320 dbi = &dbidev->dbi; 321 drm = &dbidev->drm; 322 323 bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay; 324 325 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 326 if (IS_ERR(dbi->reset)) { 327 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n"); 328 return PTR_ERR(dbi->reset); 329 } 330 331 a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW); 332 if (IS_ERR(a0)) { 333 DRM_DEV_ERROR(dev, "Failed to get gpio 'a0'\n"); 334 return PTR_ERR(a0); 335 } 336 337 device_property_read_u32(dev, "rotation", &rotation); 338 339 ret = mipi_dbi_spi_init(spi, dbi, a0); 340 if (ret) 341 return ret; 342 343 /* Cannot read from this controller via SPI */ 344 dbi->read_commands = NULL; 345 346 ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs, 347 st7586_formats, ARRAY_SIZE(st7586_formats), 348 &st7586_mode, rotation, bufsize); 349 if (ret) 350 return ret; 351 352 /* 353 * we are using 8-bit data, so we are not actually swapping anything, 354 * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the 355 * right thing and not use 16-bit transfers (which results in swapped 356 * bytes on little-endian systems and causes out of order data to be 357 * sent to the display). 358 */ 359 dbi->swap_bytes = true; 360 361 drm_mode_config_reset(drm); 362 363 ret = drm_dev_register(drm, 0); 364 if (ret) 365 return ret; 366 367 spi_set_drvdata(spi, drm); 368 369 drm_fbdev_generic_setup(drm, 0); 370 371 return 0; 372 } 373 374 static int st7586_remove(struct spi_device *spi) 375 { 376 struct drm_device *drm = spi_get_drvdata(spi); 377 378 drm_dev_unplug(drm); 379 drm_atomic_helper_shutdown(drm); 380 381 return 0; 382 } 383 384 static void st7586_shutdown(struct spi_device *spi) 385 { 386 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 387 } 388 389 static struct spi_driver st7586_spi_driver = { 390 .driver = { 391 .name = "st7586", 392 .owner = THIS_MODULE, 393 .of_match_table = st7586_of_match, 394 }, 395 .id_table = st7586_id, 396 .probe = st7586_probe, 397 .remove = st7586_remove, 398 .shutdown = st7586_shutdown, 399 }; 400 module_spi_driver(st7586_spi_driver); 401 402 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver"); 403 MODULE_AUTHOR("David Lechner <david@lechnology.com>"); 404 MODULE_LICENSE("GPL"); 405