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_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 <david@lechnology.com>"); 395 MODULE_LICENSE("GPL"); 396