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_cma_helper.h> 19 #include <drm/drm_fb_helper.h> 20 #include <drm/drm_format_helper.h> 21 #include <drm/drm_gem_atomic_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 void *src = cma_obj->vaddr; 96 int ret = 0; 97 98 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE); 99 if (ret) 100 return ret; 101 102 st7586_xrgb8888_to_gray332(dst, src, fb, clip); 103 104 drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE); 105 106 return 0; 107 } 108 109 static void st7586_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) 110 { 111 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev); 112 struct mipi_dbi *dbi = &dbidev->dbi; 113 int start, end, idx, ret = 0; 114 115 if (!drm_dev_enter(fb->dev, &idx)) 116 return; 117 118 /* 3 pixels per byte, so grow clip to nearest multiple of 3 */ 119 rect->x1 = rounddown(rect->x1, 3); 120 rect->x2 = roundup(rect->x2, 3); 121 122 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect)); 123 124 ret = st7586_buf_copy(dbidev->tx_buf, fb, rect); 125 if (ret) 126 goto err_msg; 127 128 /* Pixels are packed 3 per byte */ 129 start = rect->x1 / 3; 130 end = rect->x2 / 3; 131 132 mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS, 133 (start >> 8) & 0xFF, start & 0xFF, 134 (end >> 8) & 0xFF, (end - 1) & 0xFF); 135 mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS, 136 (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF, 137 (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF); 138 139 ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, 140 (u8 *)dbidev->tx_buf, 141 (end - start) * (rect->y2 - rect->y1)); 142 err_msg: 143 if (ret) 144 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret); 145 146 drm_dev_exit(idx); 147 } 148 149 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe, 150 struct drm_plane_state *old_state) 151 { 152 struct drm_plane_state *state = pipe->plane.state; 153 struct drm_rect rect; 154 155 if (!pipe->crtc.state->active) 156 return; 157 158 if (drm_atomic_helper_damage_merged(old_state, state, &rect)) 159 st7586_fb_dirty(state->fb, &rect); 160 } 161 162 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe, 163 struct drm_crtc_state *crtc_state, 164 struct drm_plane_state *plane_state) 165 { 166 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 167 struct drm_framebuffer *fb = plane_state->fb; 168 struct mipi_dbi *dbi = &dbidev->dbi; 169 struct drm_rect rect = { 170 .x1 = 0, 171 .x2 = fb->width, 172 .y1 = 0, 173 .y2 = fb->height, 174 }; 175 int idx, ret; 176 u8 addr_mode; 177 178 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 179 return; 180 181 DRM_DEBUG_KMS("\n"); 182 183 ret = mipi_dbi_poweron_reset(dbidev); 184 if (ret) 185 goto out_exit; 186 187 mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f); 188 mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00); 189 190 msleep(10); 191 192 mipi_dbi_command(dbi, ST7586_OTP_READ); 193 194 msleep(20); 195 196 mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT); 197 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE); 198 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF); 199 200 msleep(50); 201 202 mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00); 203 mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00); 204 mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02); 205 mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04); 206 mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d); 207 mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00); 208 mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY); 209 mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02); 210 211 switch (dbidev->rotation) { 212 default: 213 addr_mode = 0x00; 214 break; 215 case 90: 216 addr_mode = ST7586_DISP_CTRL_MY; 217 break; 218 case 180: 219 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY; 220 break; 221 case 270: 222 addr_mode = ST7586_DISP_CTRL_MX; 223 break; 224 } 225 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode); 226 227 mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f); 228 mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0); 229 mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77); 230 mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE); 231 232 msleep(100); 233 234 st7586_fb_dirty(fb, &rect); 235 236 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON); 237 out_exit: 238 drm_dev_exit(idx); 239 } 240 241 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe) 242 { 243 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 244 245 /* 246 * This callback is not protected by drm_dev_enter/exit since we want to 247 * turn off the display on regular driver unload. It's highly unlikely 248 * that the underlying SPI controller is gone should this be called after 249 * unplug. 250 */ 251 252 DRM_DEBUG_KMS("\n"); 253 254 mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF); 255 } 256 257 static const u32 st7586_formats[] = { 258 DRM_FORMAT_XRGB8888, 259 }; 260 261 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = { 262 .enable = st7586_pipe_enable, 263 .disable = st7586_pipe_disable, 264 .update = st7586_pipe_update, 265 }; 266 267 static const struct drm_display_mode st7586_mode = { 268 DRM_SIMPLE_MODE(178, 128, 37, 27), 269 }; 270 271 DEFINE_DRM_GEM_CMA_FOPS(st7586_fops); 272 273 static const struct drm_driver st7586_driver = { 274 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 275 .fops = &st7586_fops, 276 DRM_GEM_CMA_DRIVER_OPS_VMAP, 277 .debugfs_init = mipi_dbi_debugfs_init, 278 .name = "st7586", 279 .desc = "Sitronix ST7586", 280 .date = "20170801", 281 .major = 1, 282 .minor = 0, 283 }; 284 285 static const struct of_device_id st7586_of_match[] = { 286 { .compatible = "lego,ev3-lcd" }, 287 {}, 288 }; 289 MODULE_DEVICE_TABLE(of, st7586_of_match); 290 291 static const struct spi_device_id st7586_id[] = { 292 { "ev3-lcd", 0 }, 293 { }, 294 }; 295 MODULE_DEVICE_TABLE(spi, st7586_id); 296 297 static int st7586_probe(struct spi_device *spi) 298 { 299 struct device *dev = &spi->dev; 300 struct mipi_dbi_dev *dbidev; 301 struct drm_device *drm; 302 struct mipi_dbi *dbi; 303 struct gpio_desc *a0; 304 u32 rotation = 0; 305 size_t bufsize; 306 int ret; 307 308 dbidev = devm_drm_dev_alloc(dev, &st7586_driver, 309 struct mipi_dbi_dev, drm); 310 if (IS_ERR(dbidev)) 311 return PTR_ERR(dbidev); 312 313 dbi = &dbidev->dbi; 314 drm = &dbidev->drm; 315 316 bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay; 317 318 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 319 if (IS_ERR(dbi->reset)) 320 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n"); 321 322 a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW); 323 if (IS_ERR(a0)) 324 return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n"); 325 326 device_property_read_u32(dev, "rotation", &rotation); 327 328 ret = mipi_dbi_spi_init(spi, dbi, a0); 329 if (ret) 330 return ret; 331 332 /* Cannot read from this controller via SPI */ 333 dbi->read_commands = NULL; 334 335 ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs, 336 st7586_formats, ARRAY_SIZE(st7586_formats), 337 &st7586_mode, rotation, bufsize); 338 if (ret) 339 return ret; 340 341 /* 342 * we are using 8-bit data, so we are not actually swapping anything, 343 * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the 344 * right thing and not use 16-bit transfers (which results in swapped 345 * bytes on little-endian systems and causes out of order data to be 346 * sent to the display). 347 */ 348 dbi->swap_bytes = true; 349 350 drm_mode_config_reset(drm); 351 352 ret = drm_dev_register(drm, 0); 353 if (ret) 354 return ret; 355 356 spi_set_drvdata(spi, drm); 357 358 drm_fbdev_generic_setup(drm, 0); 359 360 return 0; 361 } 362 363 static int st7586_remove(struct spi_device *spi) 364 { 365 struct drm_device *drm = spi_get_drvdata(spi); 366 367 drm_dev_unplug(drm); 368 drm_atomic_helper_shutdown(drm); 369 370 return 0; 371 } 372 373 static void st7586_shutdown(struct spi_device *spi) 374 { 375 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 376 } 377 378 static struct spi_driver st7586_spi_driver = { 379 .driver = { 380 .name = "st7586", 381 .owner = THIS_MODULE, 382 .of_match_table = st7586_of_match, 383 }, 384 .id_table = st7586_id, 385 .probe = st7586_probe, 386 .remove = st7586_remove, 387 .shutdown = st7586_shutdown, 388 }; 389 module_spi_driver(st7586_spi_driver); 390 391 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver"); 392 MODULE_AUTHOR("David Lechner <david@lechnology.com>"); 393 MODULE_LICENSE("GPL"); 394