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/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 <david@lechnology.com>"); 406 MODULE_LICENSE("GPL"); 407