1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Driver for the Solomon SSD1307 OLED controller 4 * 5 * Copyright 2012 Free Electrons 6 */ 7 8 #include <linux/backlight.h> 9 #include <linux/delay.h> 10 #include <linux/fb.h> 11 #include <linux/gpio/consumer.h> 12 #include <linux/i2c.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/of_device.h> 16 #include <linux/of_gpio.h> 17 #include <linux/pwm.h> 18 #include <linux/uaccess.h> 19 #include <linux/regulator/consumer.h> 20 21 #define SSD1307FB_DATA 0x40 22 #define SSD1307FB_COMMAND 0x80 23 24 #define SSD1307FB_SET_ADDRESS_MODE 0x20 25 #define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL (0x00) 26 #define SSD1307FB_SET_ADDRESS_MODE_VERTICAL (0x01) 27 #define SSD1307FB_SET_ADDRESS_MODE_PAGE (0x02) 28 #define SSD1307FB_SET_COL_RANGE 0x21 29 #define SSD1307FB_SET_PAGE_RANGE 0x22 30 #define SSD1307FB_CONTRAST 0x81 31 #define SSD1307FB_CHARGE_PUMP 0x8d 32 #define SSD1307FB_SEG_REMAP_ON 0xa1 33 #define SSD1307FB_DISPLAY_OFF 0xae 34 #define SSD1307FB_SET_MULTIPLEX_RATIO 0xa8 35 #define SSD1307FB_DISPLAY_ON 0xaf 36 #define SSD1307FB_START_PAGE_ADDRESS 0xb0 37 #define SSD1307FB_SET_DISPLAY_OFFSET 0xd3 38 #define SSD1307FB_SET_CLOCK_FREQ 0xd5 39 #define SSD1307FB_SET_PRECHARGE_PERIOD 0xd9 40 #define SSD1307FB_SET_COM_PINS_CONFIG 0xda 41 #define SSD1307FB_SET_VCOMH 0xdb 42 43 #define MAX_CONTRAST 255 44 45 #define REFRESHRATE 1 46 47 static u_int refreshrate = REFRESHRATE; 48 module_param(refreshrate, uint, 0); 49 50 struct ssd1307fb_par; 51 52 struct ssd1307fb_deviceinfo { 53 u32 default_vcomh; 54 u32 default_dclk_div; 55 u32 default_dclk_frq; 56 int need_pwm; 57 int need_chargepump; 58 }; 59 60 struct ssd1307fb_par { 61 u32 com_invdir; 62 u32 com_lrremap; 63 u32 com_offset; 64 u32 com_seq; 65 u32 contrast; 66 u32 dclk_div; 67 u32 dclk_frq; 68 const struct ssd1307fb_deviceinfo *device_info; 69 struct i2c_client *client; 70 u32 height; 71 struct fb_info *info; 72 u32 page_offset; 73 u32 prechargep1; 74 u32 prechargep2; 75 struct pwm_device *pwm; 76 u32 pwm_period; 77 struct gpio_desc *reset; 78 struct regulator *vbat_reg; 79 u32 seg_remap; 80 u32 vcomh; 81 u32 width; 82 }; 83 84 struct ssd1307fb_array { 85 u8 type; 86 u8 data[0]; 87 }; 88 89 static const struct fb_fix_screeninfo ssd1307fb_fix = { 90 .id = "Solomon SSD1307", 91 .type = FB_TYPE_PACKED_PIXELS, 92 .visual = FB_VISUAL_MONO10, 93 .xpanstep = 0, 94 .ypanstep = 0, 95 .ywrapstep = 0, 96 .accel = FB_ACCEL_NONE, 97 }; 98 99 static const struct fb_var_screeninfo ssd1307fb_var = { 100 .bits_per_pixel = 1, 101 }; 102 103 static struct ssd1307fb_array *ssd1307fb_alloc_array(u32 len, u8 type) 104 { 105 struct ssd1307fb_array *array; 106 107 array = kzalloc(sizeof(struct ssd1307fb_array) + len, GFP_KERNEL); 108 if (!array) 109 return NULL; 110 111 array->type = type; 112 113 return array; 114 } 115 116 static int ssd1307fb_write_array(struct i2c_client *client, 117 struct ssd1307fb_array *array, u32 len) 118 { 119 int ret; 120 121 len += sizeof(struct ssd1307fb_array); 122 123 ret = i2c_master_send(client, (u8 *)array, len); 124 if (ret != len) { 125 dev_err(&client->dev, "Couldn't send I2C command.\n"); 126 return ret; 127 } 128 129 return 0; 130 } 131 132 static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd) 133 { 134 struct ssd1307fb_array *array; 135 int ret; 136 137 array = ssd1307fb_alloc_array(1, SSD1307FB_COMMAND); 138 if (!array) 139 return -ENOMEM; 140 141 array->data[0] = cmd; 142 143 ret = ssd1307fb_write_array(client, array, 1); 144 kfree(array); 145 146 return ret; 147 } 148 149 static void ssd1307fb_update_display(struct ssd1307fb_par *par) 150 { 151 struct ssd1307fb_array *array; 152 u8 *vmem = par->info->screen_base; 153 int i, j, k; 154 155 array = ssd1307fb_alloc_array(par->width * par->height / 8, 156 SSD1307FB_DATA); 157 if (!array) 158 return; 159 160 /* 161 * The screen is divided in pages, each having a height of 8 162 * pixels, and the width of the screen. When sending a byte of 163 * data to the controller, it gives the 8 bits for the current 164 * column. I.e, the first byte are the 8 bits of the first 165 * column, then the 8 bits for the second column, etc. 166 * 167 * 168 * Representation of the screen, assuming it is 5 bits 169 * wide. Each letter-number combination is a bit that controls 170 * one pixel. 171 * 172 * A0 A1 A2 A3 A4 173 * B0 B1 B2 B3 B4 174 * C0 C1 C2 C3 C4 175 * D0 D1 D2 D3 D4 176 * E0 E1 E2 E3 E4 177 * F0 F1 F2 F3 F4 178 * G0 G1 G2 G3 G4 179 * H0 H1 H2 H3 H4 180 * 181 * If you want to update this screen, you need to send 5 bytes: 182 * (1) A0 B0 C0 D0 E0 F0 G0 H0 183 * (2) A1 B1 C1 D1 E1 F1 G1 H1 184 * (3) A2 B2 C2 D2 E2 F2 G2 H2 185 * (4) A3 B3 C3 D3 E3 F3 G3 H3 186 * (5) A4 B4 C4 D4 E4 F4 G4 H4 187 */ 188 189 for (i = 0; i < (par->height / 8); i++) { 190 for (j = 0; j < par->width; j++) { 191 u32 array_idx = i * par->width + j; 192 array->data[array_idx] = 0; 193 for (k = 0; k < 8; k++) { 194 u32 page_length = par->width * i; 195 u32 index = page_length + (par->width * k + j) / 8; 196 u8 byte = *(vmem + index); 197 u8 bit = byte & (1 << (j % 8)); 198 bit = bit >> (j % 8); 199 array->data[array_idx] |= bit << k; 200 } 201 } 202 } 203 204 ssd1307fb_write_array(par->client, array, par->width * par->height / 8); 205 kfree(array); 206 } 207 208 209 static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf, 210 size_t count, loff_t *ppos) 211 { 212 struct ssd1307fb_par *par = info->par; 213 unsigned long total_size; 214 unsigned long p = *ppos; 215 u8 __iomem *dst; 216 217 total_size = info->fix.smem_len; 218 219 if (p > total_size) 220 return -EINVAL; 221 222 if (count + p > total_size) 223 count = total_size - p; 224 225 if (!count) 226 return -EINVAL; 227 228 dst = (void __force *) (info->screen_base + p); 229 230 if (copy_from_user(dst, buf, count)) 231 return -EFAULT; 232 233 ssd1307fb_update_display(par); 234 235 *ppos += count; 236 237 return count; 238 } 239 240 static int ssd1307fb_blank(int blank_mode, struct fb_info *info) 241 { 242 struct ssd1307fb_par *par = info->par; 243 244 if (blank_mode != FB_BLANK_UNBLANK) 245 return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF); 246 else 247 return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON); 248 } 249 250 static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect) 251 { 252 struct ssd1307fb_par *par = info->par; 253 sys_fillrect(info, rect); 254 ssd1307fb_update_display(par); 255 } 256 257 static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area) 258 { 259 struct ssd1307fb_par *par = info->par; 260 sys_copyarea(info, area); 261 ssd1307fb_update_display(par); 262 } 263 264 static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image) 265 { 266 struct ssd1307fb_par *par = info->par; 267 sys_imageblit(info, image); 268 ssd1307fb_update_display(par); 269 } 270 271 static struct fb_ops ssd1307fb_ops = { 272 .owner = THIS_MODULE, 273 .fb_read = fb_sys_read, 274 .fb_write = ssd1307fb_write, 275 .fb_blank = ssd1307fb_blank, 276 .fb_fillrect = ssd1307fb_fillrect, 277 .fb_copyarea = ssd1307fb_copyarea, 278 .fb_imageblit = ssd1307fb_imageblit, 279 }; 280 281 static void ssd1307fb_deferred_io(struct fb_info *info, 282 struct list_head *pagelist) 283 { 284 ssd1307fb_update_display(info->par); 285 } 286 287 static int ssd1307fb_init(struct ssd1307fb_par *par) 288 { 289 int ret; 290 u32 precharge, dclk, com_invdir, compins; 291 struct pwm_args pargs; 292 293 if (par->device_info->need_pwm) { 294 par->pwm = pwm_get(&par->client->dev, NULL); 295 if (IS_ERR(par->pwm)) { 296 dev_err(&par->client->dev, "Could not get PWM from device tree!\n"); 297 return PTR_ERR(par->pwm); 298 } 299 300 /* 301 * FIXME: pwm_apply_args() should be removed when switching to 302 * the atomic PWM API. 303 */ 304 pwm_apply_args(par->pwm); 305 306 pwm_get_args(par->pwm, &pargs); 307 308 par->pwm_period = pargs.period; 309 /* Enable the PWM */ 310 pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period); 311 pwm_enable(par->pwm); 312 313 dev_dbg(&par->client->dev, "Using PWM%d with a %dns period.\n", 314 par->pwm->pwm, par->pwm_period); 315 }; 316 317 /* Set initial contrast */ 318 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST); 319 if (ret < 0) 320 return ret; 321 322 ret = ssd1307fb_write_cmd(par->client, par->contrast); 323 if (ret < 0) 324 return ret; 325 326 /* Set segment re-map */ 327 if (par->seg_remap) { 328 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON); 329 if (ret < 0) 330 return ret; 331 }; 332 333 /* Set COM direction */ 334 com_invdir = 0xc0 | (par->com_invdir & 0x1) << 3; 335 ret = ssd1307fb_write_cmd(par->client, com_invdir); 336 if (ret < 0) 337 return ret; 338 339 /* Set multiplex ratio value */ 340 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO); 341 if (ret < 0) 342 return ret; 343 344 ret = ssd1307fb_write_cmd(par->client, par->height - 1); 345 if (ret < 0) 346 return ret; 347 348 /* set display offset value */ 349 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET); 350 if (ret < 0) 351 return ret; 352 353 ret = ssd1307fb_write_cmd(par->client, par->com_offset); 354 if (ret < 0) 355 return ret; 356 357 /* Set clock frequency */ 358 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ); 359 if (ret < 0) 360 return ret; 361 362 dclk = ((par->dclk_div - 1) & 0xf) | (par->dclk_frq & 0xf) << 4; 363 ret = ssd1307fb_write_cmd(par->client, dclk); 364 if (ret < 0) 365 return ret; 366 367 /* Set precharge period in number of ticks from the internal clock */ 368 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD); 369 if (ret < 0) 370 return ret; 371 372 precharge = (par->prechargep1 & 0xf) | (par->prechargep2 & 0xf) << 4; 373 ret = ssd1307fb_write_cmd(par->client, precharge); 374 if (ret < 0) 375 return ret; 376 377 /* Set COM pins configuration */ 378 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG); 379 if (ret < 0) 380 return ret; 381 382 compins = 0x02 | !(par->com_seq & 0x1) << 4 383 | (par->com_lrremap & 0x1) << 5; 384 ret = ssd1307fb_write_cmd(par->client, compins); 385 if (ret < 0) 386 return ret; 387 388 /* Set VCOMH */ 389 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH); 390 if (ret < 0) 391 return ret; 392 393 ret = ssd1307fb_write_cmd(par->client, par->vcomh); 394 if (ret < 0) 395 return ret; 396 397 /* Turn on the DC-DC Charge Pump */ 398 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP); 399 if (ret < 0) 400 return ret; 401 402 ret = ssd1307fb_write_cmd(par->client, 403 BIT(4) | (par->device_info->need_chargepump ? BIT(2) : 0)); 404 if (ret < 0) 405 return ret; 406 407 /* Switch to horizontal addressing mode */ 408 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE); 409 if (ret < 0) 410 return ret; 411 412 ret = ssd1307fb_write_cmd(par->client, 413 SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL); 414 if (ret < 0) 415 return ret; 416 417 /* Set column range */ 418 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE); 419 if (ret < 0) 420 return ret; 421 422 ret = ssd1307fb_write_cmd(par->client, 0x0); 423 if (ret < 0) 424 return ret; 425 426 ret = ssd1307fb_write_cmd(par->client, par->width - 1); 427 if (ret < 0) 428 return ret; 429 430 /* Set page range */ 431 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE); 432 if (ret < 0) 433 return ret; 434 435 ret = ssd1307fb_write_cmd(par->client, 0x0); 436 if (ret < 0) 437 return ret; 438 439 ret = ssd1307fb_write_cmd(par->client, 440 par->page_offset + (par->height / 8) - 1); 441 if (ret < 0) 442 return ret; 443 444 /* Clear the screen */ 445 ssd1307fb_update_display(par); 446 447 /* Turn on the display */ 448 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON); 449 if (ret < 0) 450 return ret; 451 452 return 0; 453 } 454 455 static int ssd1307fb_update_bl(struct backlight_device *bdev) 456 { 457 struct ssd1307fb_par *par = bl_get_data(bdev); 458 int ret; 459 int brightness = bdev->props.brightness; 460 461 par->contrast = brightness; 462 463 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST); 464 if (ret < 0) 465 return ret; 466 ret = ssd1307fb_write_cmd(par->client, par->contrast); 467 if (ret < 0) 468 return ret; 469 return 0; 470 } 471 472 static int ssd1307fb_get_brightness(struct backlight_device *bdev) 473 { 474 struct ssd1307fb_par *par = bl_get_data(bdev); 475 476 return par->contrast; 477 } 478 479 static int ssd1307fb_check_fb(struct backlight_device *bdev, 480 struct fb_info *info) 481 { 482 return (info->bl_dev == bdev); 483 } 484 485 static const struct backlight_ops ssd1307fb_bl_ops = { 486 .options = BL_CORE_SUSPENDRESUME, 487 .update_status = ssd1307fb_update_bl, 488 .get_brightness = ssd1307fb_get_brightness, 489 .check_fb = ssd1307fb_check_fb, 490 }; 491 492 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1305_deviceinfo = { 493 .default_vcomh = 0x34, 494 .default_dclk_div = 1, 495 .default_dclk_frq = 7, 496 }; 497 498 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1306_deviceinfo = { 499 .default_vcomh = 0x20, 500 .default_dclk_div = 1, 501 .default_dclk_frq = 8, 502 .need_chargepump = 1, 503 }; 504 505 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1307_deviceinfo = { 506 .default_vcomh = 0x20, 507 .default_dclk_div = 2, 508 .default_dclk_frq = 12, 509 .need_pwm = 1, 510 }; 511 512 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1309_deviceinfo = { 513 .default_vcomh = 0x34, 514 .default_dclk_div = 1, 515 .default_dclk_frq = 10, 516 }; 517 518 static const struct of_device_id ssd1307fb_of_match[] = { 519 { 520 .compatible = "solomon,ssd1305fb-i2c", 521 .data = (void *)&ssd1307fb_ssd1305_deviceinfo, 522 }, 523 { 524 .compatible = "solomon,ssd1306fb-i2c", 525 .data = (void *)&ssd1307fb_ssd1306_deviceinfo, 526 }, 527 { 528 .compatible = "solomon,ssd1307fb-i2c", 529 .data = (void *)&ssd1307fb_ssd1307_deviceinfo, 530 }, 531 { 532 .compatible = "solomon,ssd1309fb-i2c", 533 .data = (void *)&ssd1307fb_ssd1309_deviceinfo, 534 }, 535 {}, 536 }; 537 MODULE_DEVICE_TABLE(of, ssd1307fb_of_match); 538 539 static int ssd1307fb_probe(struct i2c_client *client, 540 const struct i2c_device_id *id) 541 { 542 struct backlight_device *bl; 543 char bl_name[12]; 544 struct fb_info *info; 545 struct device_node *node = client->dev.of_node; 546 struct fb_deferred_io *ssd1307fb_defio; 547 u32 vmem_size; 548 struct ssd1307fb_par *par; 549 u8 *vmem; 550 int ret; 551 552 if (!node) { 553 dev_err(&client->dev, "No device tree data found!\n"); 554 return -EINVAL; 555 } 556 557 info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev); 558 if (!info) { 559 dev_err(&client->dev, "Couldn't allocate framebuffer.\n"); 560 return -ENOMEM; 561 } 562 563 par = info->par; 564 par->info = info; 565 par->client = client; 566 567 par->device_info = of_device_get_match_data(&client->dev); 568 569 par->reset = devm_gpiod_get_optional(&client->dev, "reset", 570 GPIOD_OUT_LOW); 571 if (IS_ERR(par->reset)) { 572 dev_err(&client->dev, "failed to get reset gpio: %ld\n", 573 PTR_ERR(par->reset)); 574 ret = PTR_ERR(par->reset); 575 goto fb_alloc_error; 576 } 577 578 par->vbat_reg = devm_regulator_get_optional(&client->dev, "vbat"); 579 if (IS_ERR(par->vbat_reg)) { 580 ret = PTR_ERR(par->vbat_reg); 581 if (ret == -ENODEV) { 582 par->vbat_reg = NULL; 583 } else { 584 dev_err(&client->dev, "failed to get VBAT regulator: %d\n", 585 ret); 586 goto fb_alloc_error; 587 } 588 } 589 590 if (of_property_read_u32(node, "solomon,width", &par->width)) 591 par->width = 96; 592 593 if (of_property_read_u32(node, "solomon,height", &par->height)) 594 par->height = 16; 595 596 if (of_property_read_u32(node, "solomon,page-offset", &par->page_offset)) 597 par->page_offset = 1; 598 599 if (of_property_read_u32(node, "solomon,com-offset", &par->com_offset)) 600 par->com_offset = 0; 601 602 if (of_property_read_u32(node, "solomon,prechargep1", &par->prechargep1)) 603 par->prechargep1 = 2; 604 605 if (of_property_read_u32(node, "solomon,prechargep2", &par->prechargep2)) 606 par->prechargep2 = 2; 607 608 par->seg_remap = !of_property_read_bool(node, "solomon,segment-no-remap"); 609 par->com_seq = of_property_read_bool(node, "solomon,com-seq"); 610 par->com_lrremap = of_property_read_bool(node, "solomon,com-lrremap"); 611 par->com_invdir = of_property_read_bool(node, "solomon,com-invdir"); 612 613 par->contrast = 127; 614 par->vcomh = par->device_info->default_vcomh; 615 616 /* Setup display timing */ 617 par->dclk_div = par->device_info->default_dclk_div; 618 par->dclk_frq = par->device_info->default_dclk_frq; 619 620 vmem_size = par->width * par->height / 8; 621 622 vmem = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 623 get_order(vmem_size)); 624 if (!vmem) { 625 dev_err(&client->dev, "Couldn't allocate graphical memory.\n"); 626 ret = -ENOMEM; 627 goto fb_alloc_error; 628 } 629 630 ssd1307fb_defio = devm_kzalloc(&client->dev, sizeof(*ssd1307fb_defio), 631 GFP_KERNEL); 632 if (!ssd1307fb_defio) { 633 dev_err(&client->dev, "Couldn't allocate deferred io.\n"); 634 ret = -ENOMEM; 635 goto fb_alloc_error; 636 } 637 638 ssd1307fb_defio->delay = HZ / refreshrate; 639 ssd1307fb_defio->deferred_io = ssd1307fb_deferred_io; 640 641 info->fbops = &ssd1307fb_ops; 642 info->fix = ssd1307fb_fix; 643 info->fix.line_length = par->width / 8; 644 info->fbdefio = ssd1307fb_defio; 645 646 info->var = ssd1307fb_var; 647 info->var.xres = par->width; 648 info->var.xres_virtual = par->width; 649 info->var.yres = par->height; 650 info->var.yres_virtual = par->height; 651 652 info->var.red.length = 1; 653 info->var.red.offset = 0; 654 info->var.green.length = 1; 655 info->var.green.offset = 0; 656 info->var.blue.length = 1; 657 info->var.blue.offset = 0; 658 659 info->screen_base = (u8 __force __iomem *)vmem; 660 info->fix.smem_start = __pa(vmem); 661 info->fix.smem_len = vmem_size; 662 663 fb_deferred_io_init(info); 664 665 i2c_set_clientdata(client, info); 666 667 if (par->reset) { 668 /* Reset the screen */ 669 gpiod_set_value_cansleep(par->reset, 1); 670 udelay(4); 671 gpiod_set_value_cansleep(par->reset, 0); 672 udelay(4); 673 } 674 675 if (par->vbat_reg) { 676 ret = regulator_enable(par->vbat_reg); 677 if (ret) { 678 dev_err(&client->dev, "failed to enable VBAT: %d\n", 679 ret); 680 goto reset_oled_error; 681 } 682 } 683 684 ret = ssd1307fb_init(par); 685 if (ret) 686 goto regulator_enable_error; 687 688 ret = register_framebuffer(info); 689 if (ret) { 690 dev_err(&client->dev, "Couldn't register the framebuffer\n"); 691 goto panel_init_error; 692 } 693 694 snprintf(bl_name, sizeof(bl_name), "ssd1307fb%d", info->node); 695 bl = backlight_device_register(bl_name, &client->dev, par, 696 &ssd1307fb_bl_ops, NULL); 697 if (IS_ERR(bl)) { 698 ret = PTR_ERR(bl); 699 dev_err(&client->dev, "unable to register backlight device: %d\n", 700 ret); 701 goto bl_init_error; 702 } 703 704 bl->props.brightness = par->contrast; 705 bl->props.max_brightness = MAX_CONTRAST; 706 info->bl_dev = bl; 707 708 dev_info(&client->dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size); 709 710 return 0; 711 712 bl_init_error: 713 unregister_framebuffer(info); 714 panel_init_error: 715 if (par->device_info->need_pwm) { 716 pwm_disable(par->pwm); 717 pwm_put(par->pwm); 718 }; 719 regulator_enable_error: 720 if (par->vbat_reg) 721 regulator_disable(par->vbat_reg); 722 reset_oled_error: 723 fb_deferred_io_cleanup(info); 724 fb_alloc_error: 725 framebuffer_release(info); 726 return ret; 727 } 728 729 static int ssd1307fb_remove(struct i2c_client *client) 730 { 731 struct fb_info *info = i2c_get_clientdata(client); 732 struct ssd1307fb_par *par = info->par; 733 734 ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF); 735 736 backlight_device_unregister(info->bl_dev); 737 738 unregister_framebuffer(info); 739 if (par->device_info->need_pwm) { 740 pwm_disable(par->pwm); 741 pwm_put(par->pwm); 742 }; 743 fb_deferred_io_cleanup(info); 744 __free_pages(__va(info->fix.smem_start), get_order(info->fix.smem_len)); 745 framebuffer_release(info); 746 747 return 0; 748 } 749 750 static const struct i2c_device_id ssd1307fb_i2c_id[] = { 751 { "ssd1305fb", 0 }, 752 { "ssd1306fb", 0 }, 753 { "ssd1307fb", 0 }, 754 { "ssd1309fb", 0 }, 755 { } 756 }; 757 MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id); 758 759 static struct i2c_driver ssd1307fb_driver = { 760 .probe = ssd1307fb_probe, 761 .remove = ssd1307fb_remove, 762 .id_table = ssd1307fb_i2c_id, 763 .driver = { 764 .name = "ssd1307fb", 765 .of_match_table = ssd1307fb_of_match, 766 }, 767 }; 768 769 module_i2c_driver(ssd1307fb_driver); 770 771 MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller"); 772 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>"); 773 MODULE_LICENSE("GPL"); 774