drivers/video/fbdev/ssd1307fb.c

   1 /*
   2  * Driver for the Solomon SSD1307 OLED controller
   3  *
   4  * Copyright 2012 Free Electrons
   5  *
   6  * Licensed under the GPLv2 or later.
   7  */
   8
   9 #include <linux/backlight.h>
  10 #include <linux/delay.h>
  11 #include <linux/fb.h>
  12 #include <linux/gpio/consumer.h>
  13 #include <linux/i2c.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/of_device.h>
  17 #include <linux/of_gpio.h>
  18 #include <linux/pwm.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/regulator/consumer.h>
  21
  22 #define SSD1307FB_DATA                  0x40
  23 #define SSD1307FB_COMMAND               0x80
  24
  25 #define SSD1307FB_SET_ADDRESS_MODE      0x20
  26 #define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL   (0x00)
  27 #define SSD1307FB_SET_ADDRESS_MODE_VERTICAL     (0x01)
  28 #define SSD1307FB_SET_ADDRESS_MODE_PAGE         (0x02)
  29 #define SSD1307FB_SET_COL_RANGE         0x21
  30 #define SSD1307FB_SET_PAGE_RANGE        0x22
  31 #define SSD1307FB_CONTRAST              0x81
  32 #define SSD1307FB_CHARGE_PUMP           0x8d
  33 #define SSD1307FB_SEG_REMAP_ON          0xa1
  34 #define SSD1307FB_DISPLAY_OFF           0xae
  35 #define SSD1307FB_SET_MULTIPLEX_RATIO   0xa8
  36 #define SSD1307FB_DISPLAY_ON            0xaf
  37 #define SSD1307FB_START_PAGE_ADDRESS    0xb0
  38 #define SSD1307FB_SET_DISPLAY_OFFSET    0xd3
  39 #define SSD1307FB_SET_CLOCK_FREQ        0xd5
  40 #define SSD1307FB_SET_PRECHARGE_PERIOD  0xd9
  41 #define SSD1307FB_SET_COM_PINS_CONFIG   0xda
  42 #define SSD1307FB_SET_VCOMH             0xdb
  43
  44 #define MAX_CONTRAST 255
  45
  46 #define REFRESHRATE 1
  47
  48 static u_int refreshrate = REFRESHRATE;
  49 module_param(refreshrate, uint, 0);
  50
  51 struct ssd1307fb_par;
  52
  53 struct ssd1307fb_deviceinfo {
  54         u32 default_vcomh;
  55         u32 default_dclk_div;
  56         u32 default_dclk_frq;
  57         int need_pwm;
  58         int need_chargepump;
  59 };
  60
  61 struct ssd1307fb_par {
  62         u32 com_invdir;
  63         u32 com_lrremap;
  64         u32 com_offset;
  65         u32 com_seq;
  66         u32 contrast;
  67         u32 dclk_div;
  68         u32 dclk_frq;
  69         const struct ssd1307fb_deviceinfo *device_info;
  70         struct i2c_client *client;
  71         u32 height;
  72         struct fb_info *info;
  73         u32 page_offset;
  74         u32 prechargep1;
  75         u32 prechargep2;
  76         struct pwm_device *pwm;
  77         u32 pwm_period;
  78         struct gpio_desc *reset;
  79         struct regulator *vbat_reg;
  80         u32 seg_remap;
  81         u32 vcomh;
  82         u32 width;
  83 };
  84
  85 struct ssd1307fb_array {
  86         u8      type;
  87         u8      data[0];
  88 };
  89
  90 static const struct fb_fix_screeninfo ssd1307fb_fix = {
  91         .id             = "Solomon SSD1307",
  92         .type           = FB_TYPE_PACKED_PIXELS,
  93         .visual         = FB_VISUAL_MONO10,
  94         .xpanstep       = 0,
  95         .ypanstep       = 0,
  96         .ywrapstep      = 0,
  97         .accel          = FB_ACCEL_NONE,
  98 };
  99
 100 static const struct fb_var_screeninfo ssd1307fb_var = {
 101         .bits_per_pixel = 1,
 102 };
 103
 104 static struct ssd1307fb_array *ssd1307fb_alloc_array(u32 len, u8 type)
 105 {
 106         struct ssd1307fb_array *array;
 107
 108         array = kzalloc(sizeof(struct ssd1307fb_array) + len, GFP_KERNEL);
 109         if (!array)
 110                 return NULL;
 111
 112         array->type = type;
 113
 114         return array;
 115 }
 116
 117 static int ssd1307fb_write_array(struct i2c_client *client,
 118                                  struct ssd1307fb_array *array, u32 len)
 119 {
 120         int ret;
 121
 122         len += sizeof(struct ssd1307fb_array);
 123
 124         ret = i2c_master_send(client, (u8 *)array, len);
 125         if (ret != len) {
 126                 dev_err(&client->dev, "Couldn't send I2C command.\n");
 127                 return ret;
 128         }
 129
 130         return 0;
 131 }
 132
 133 static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
 134 {
 135         struct ssd1307fb_array *array;
 136         int ret;
 137
 138         array = ssd1307fb_alloc_array(1, SSD1307FB_COMMAND);
 139         if (!array)
 140                 return -ENOMEM;
 141
 142         array->data[0] = cmd;
 143
 144         ret = ssd1307fb_write_array(client, array, 1);
 145         kfree(array);
 146
 147         return ret;
 148 }
 149
 150 static void ssd1307fb_update_display(struct ssd1307fb_par *par)
 151 {
 152         struct ssd1307fb_array *array;
 153         u8 *vmem = par->info->screen_base;
 154         int i, j, k;
 155
 156         array = ssd1307fb_alloc_array(par->width * par->height / 8,
 157                                       SSD1307FB_DATA);
 158         if (!array)
 159                 return;
 160
 161         /*
 162          * The screen is divided in pages, each having a height of 8
 163          * pixels, and the width of the screen. When sending a byte of
 164          * data to the controller, it gives the 8 bits for the current
 165          * column. I.e, the first byte are the 8 bits of the first
 166          * column, then the 8 bits for the second column, etc.
 167          *
 168          *
 169          * Representation of the screen, assuming it is 5 bits
 170          * wide. Each letter-number combination is a bit that controls
 171          * one pixel.
 172          *
 173          * A0 A1 A2 A3 A4
 174          * B0 B1 B2 B3 B4
 175          * C0 C1 C2 C3 C4
 176          * D0 D1 D2 D3 D4
 177          * E0 E1 E2 E3 E4
 178          * F0 F1 F2 F3 F4
 179          * G0 G1 G2 G3 G4
 180          * H0 H1 H2 H3 H4
 181          *
 182          * If you want to update this screen, you need to send 5 bytes:
 183          *  (1) A0 B0 C0 D0 E0 F0 G0 H0
 184          *  (2) A1 B1 C1 D1 E1 F1 G1 H1
 185          *  (3) A2 B2 C2 D2 E2 F2 G2 H2
 186          *  (4) A3 B3 C3 D3 E3 F3 G3 H3
 187          *  (5) A4 B4 C4 D4 E4 F4 G4 H4
 188          */
 189
 190         for (i = 0; i < (par->height / 8); i++) {
 191                 for (j = 0; j < par->width; j++) {
 192                         u32 array_idx = i * par->width + j;
 193                         array->data[array_idx] = 0;
 194                         for (k = 0; k < 8; k++) {
 195                                 u32 page_length = par->width * i;
 196                                 u32 index = page_length + (par->width * k + j) / 8;
 197                                 u8 byte = *(vmem + index);
 198                                 u8 bit = byte & (1 << (j % 8));
 199                                 bit = bit >> (j % 8);
 200                                 array->data[array_idx] |= bit << k;
 201                         }
 202                 }
 203         }
 204
 205         ssd1307fb_write_array(par->client, array, par->width * par->height / 8);
 206         kfree(array);
 207 }
 208
 209
 210 static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
 211                 size_t count, loff_t *ppos)
 212 {
 213         struct ssd1307fb_par *par = info->par;
 214         unsigned long total_size;
 215         unsigned long p = *ppos;
 216         u8 __iomem *dst;
 217
 218         total_size = info->fix.smem_len;
 219
 220         if (p > total_size)
 221                 return -EINVAL;
 222
 223         if (count + p > total_size)
 224                 count = total_size - p;
 225
 226         if (!count)
 227                 return -EINVAL;
 228
 229         dst = (void __force *) (info->screen_base + p);
 230
 231         if (copy_from_user(dst, buf, count))
 232                 return -EFAULT;
 233
 234         ssd1307fb_update_display(par);
 235
 236         *ppos += count;
 237
 238         return count;
 239 }
 240
 241 static int ssd1307fb_blank(int blank_mode, struct fb_info *info)
 242 {
 243         struct ssd1307fb_par *par = info->par;
 244
 245         if (blank_mode != FB_BLANK_UNBLANK)
 246                 return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);
 247         else
 248                 return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
 249 }
 250
 251 static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
 252 {
 253         struct ssd1307fb_par *par = info->par;
 254         sys_fillrect(info, rect);
 255         ssd1307fb_update_display(par);
 256 }
 257
 258 static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
 259 {
 260         struct ssd1307fb_par *par = info->par;
 261         sys_copyarea(info, area);
 262         ssd1307fb_update_display(par);
 263 }
 264
 265 static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image)
 266 {
 267         struct ssd1307fb_par *par = info->par;
 268         sys_imageblit(info, image);
 269         ssd1307fb_update_display(par);
 270 }
 271
 272 static struct fb_ops ssd1307fb_ops = {
 273         .owner          = THIS_MODULE,
 274         .fb_read        = fb_sys_read,
 275         .fb_write       = ssd1307fb_write,
 276         .fb_blank       = ssd1307fb_blank,
 277         .fb_fillrect    = ssd1307fb_fillrect,
 278         .fb_copyarea    = ssd1307fb_copyarea,
 279         .fb_imageblit   = ssd1307fb_imageblit,
 280 };
 281
 282 static void ssd1307fb_deferred_io(struct fb_info *info,
 283                                 struct list_head *pagelist)
 284 {
 285         ssd1307fb_update_display(info->par);
 286 }
 287
 288 static int ssd1307fb_init(struct ssd1307fb_par *par)
 289 {
 290         int ret;
 291         u32 precharge, dclk, com_invdir, compins;
 292         struct pwm_args pargs;
 293
 294         if (par->device_info->need_pwm) {
 295                 par->pwm = pwm_get(&par->client->dev, NULL);
 296                 if (IS_ERR(par->pwm)) {
 297                         dev_err(&par->client->dev, "Could not get PWM from device tree!\n");
 298                         return PTR_ERR(par->pwm);
 299                 }
 300
 301                 /*
 302                  * FIXME: pwm_apply_args() should be removed when switching to
 303                  * the atomic PWM API.
 304                  */
 305                 pwm_apply_args(par->pwm);
 306
 307                 pwm_get_args(par->pwm, &pargs);
 308
 309                 par->pwm_period = pargs.period;
 310                 /* Enable the PWM */
 311                 pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);
 312                 pwm_enable(par->pwm);
 313
 314                 dev_dbg(&par->client->dev, "Using PWM%d with a %dns period.\n",
 315                         par->pwm->pwm, par->pwm_period);
 316         };
 317
 318         /* Set initial contrast */
 319         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
 320         if (ret < 0)
 321                 return ret;
 322
 323         ret = ssd1307fb_write_cmd(par->client, par->contrast);
 324         if (ret < 0)
 325                 return ret;
 326
 327         /* Set segment re-map */
 328         if (par->seg_remap) {
 329                 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON);
 330                 if (ret < 0)
 331                         return ret;
 332         };
 333
 334         /* Set COM direction */
 335         com_invdir = 0xc0 | (par->com_invdir & 0x1) << 3;
 336         ret = ssd1307fb_write_cmd(par->client,  com_invdir);
 337         if (ret < 0)
 338                 return ret;
 339
 340         /* Set multiplex ratio value */
 341         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO);
 342         if (ret < 0)
 343                 return ret;
 344
 345         ret = ssd1307fb_write_cmd(par->client, par->height - 1);
 346         if (ret < 0)
 347                 return ret;
 348
 349         /* set display offset value */
 350         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET);
 351         if (ret < 0)
 352                 return ret;
 353
 354         ret = ssd1307fb_write_cmd(par->client, par->com_offset);
 355         if (ret < 0)
 356                 return ret;
 357
 358         /* Set clock frequency */
 359         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ);
 360         if (ret < 0)
 361                 return ret;
 362
 363         dclk = ((par->dclk_div - 1) & 0xf) | (par->dclk_frq & 0xf) << 4;
 364         ret = ssd1307fb_write_cmd(par->client, dclk);
 365         if (ret < 0)
 366                 return ret;
 367
 368         /* Set precharge period in number of ticks from the internal clock */
 369         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD);
 370         if (ret < 0)
 371                 return ret;
 372
 373         precharge = (par->prechargep1 & 0xf) | (par->prechargep2 & 0xf) << 4;
 374         ret = ssd1307fb_write_cmd(par->client, precharge);
 375         if (ret < 0)
 376                 return ret;
 377
 378         /* Set COM pins configuration */
 379         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG);
 380         if (ret < 0)
 381                 return ret;
 382
 383         compins = 0x02 | !(par->com_seq & 0x1) << 4
 384                                    | (par->com_lrremap & 0x1) << 5;
 385         ret = ssd1307fb_write_cmd(par->client, compins);
 386         if (ret < 0)
 387                 return ret;
 388
 389         /* Set VCOMH */
 390         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH);
 391         if (ret < 0)
 392                 return ret;
 393
 394         ret = ssd1307fb_write_cmd(par->client, par->vcomh);
 395         if (ret < 0)
 396                 return ret;
 397
 398         /* Turn on the DC-DC Charge Pump */
 399         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);
 400         if (ret < 0)
 401                 return ret;
 402
 403         ret = ssd1307fb_write_cmd(par->client,
 404                 BIT(4) | (par->device_info->need_chargepump ? BIT(2) : 0));
 405         if (ret < 0)
 406                 return ret;
 407
 408         /* Switch to horizontal addressing mode */
 409         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE);
 410         if (ret < 0)
 411                 return ret;
 412
 413         ret = ssd1307fb_write_cmd(par->client,
 414                                   SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
 415         if (ret < 0)
 416                 return ret;
 417
 418         /* Set column range */
 419         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
 420         if (ret < 0)
 421                 return ret;
 422
 423         ret = ssd1307fb_write_cmd(par->client, 0x0);
 424         if (ret < 0)
 425                 return ret;
 426
 427         ret = ssd1307fb_write_cmd(par->client, par->width - 1);
 428         if (ret < 0)
 429                 return ret;
 430
 431         /* Set page range */
 432         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
 433         if (ret < 0)
 434                 return ret;
 435
 436         ret = ssd1307fb_write_cmd(par->client, 0x0);
 437         if (ret < 0)
 438                 return ret;
 439
 440         ret = ssd1307fb_write_cmd(par->client,
 441                                   par->page_offset + (par->height / 8) - 1);
 442         if (ret < 0)
 443                 return ret;
 444
 445         /* Clear the screen */
 446         ssd1307fb_update_display(par);
 447
 448         /* Turn on the display */
 449         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
 450         if (ret < 0)
 451                 return ret;
 452
 453         return 0;
 454 }
 455
 456 static int ssd1307fb_update_bl(struct backlight_device *bdev)
 457 {
 458         struct ssd1307fb_par *par = bl_get_data(bdev);
 459         int ret;
 460         int brightness = bdev->props.brightness;
 461
 462         par->contrast = brightness;
 463
 464         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
 465         if (ret < 0)
 466                 return ret;
 467         ret = ssd1307fb_write_cmd(par->client, par->contrast);
 468         if (ret < 0)
 469                 return ret;
 470         return 0;
 471 }
 472
 473 static int ssd1307fb_get_brightness(struct backlight_device *bdev)
 474 {
 475         struct ssd1307fb_par *par = bl_get_data(bdev);
 476
 477         return par->contrast;
 478 }
 479
 480 static int ssd1307fb_check_fb(struct backlight_device *bdev,
 481                                    struct fb_info *info)
 482 {
 483         return (info->bl_dev == bdev);
 484 }
 485
 486 static const struct backlight_ops ssd1307fb_bl_ops = {
 487         .options        = BL_CORE_SUSPENDRESUME,
 488         .update_status  = ssd1307fb_update_bl,
 489         .get_brightness = ssd1307fb_get_brightness,
 490         .check_fb       = ssd1307fb_check_fb,
 491 };
 492
 493 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1305_deviceinfo = {
 494         .default_vcomh = 0x34,
 495         .default_dclk_div = 1,
 496         .default_dclk_frq = 7,
 497 };
 498
 499 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1306_deviceinfo = {
 500         .default_vcomh = 0x20,
 501         .default_dclk_div = 1,
 502         .default_dclk_frq = 8,
 503         .need_chargepump = 1,
 504 };
 505
 506 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1307_deviceinfo = {
 507         .default_vcomh = 0x20,
 508         .default_dclk_div = 2,
 509         .default_dclk_frq = 12,
 510         .need_pwm = 1,
 511 };
 512
 513 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1309_deviceinfo = {
 514         .default_vcomh = 0x34,
 515         .default_dclk_div = 1,
 516         .default_dclk_frq = 10,
 517 };
 518
 519 static const struct of_device_id ssd1307fb_of_match[] = {
 520         {
 521                 .compatible = "solomon,ssd1305fb-i2c",
 522                 .data = (void *)&ssd1307fb_ssd1305_deviceinfo,
 523         },
 524         {
 525                 .compatible = "solomon,ssd1306fb-i2c",
 526                 .data = (void *)&ssd1307fb_ssd1306_deviceinfo,
 527         },
 528         {
 529                 .compatible = "solomon,ssd1307fb-i2c",
 530                 .data = (void *)&ssd1307fb_ssd1307_deviceinfo,
 531         },
 532         {
 533                 .compatible = "solomon,ssd1309fb-i2c",
 534                 .data = (void *)&ssd1307fb_ssd1309_deviceinfo,
 535         },
 536         {},
 537 };
 538 MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);
 539
 540 static int ssd1307fb_probe(struct i2c_client *client,
 541                            const struct i2c_device_id *id)
 542 {
 543         struct backlight_device *bl;
 544         char bl_name[12];
 545         struct fb_info *info;
 546         struct device_node *node = client->dev.of_node;
 547         struct fb_deferred_io *ssd1307fb_defio;
 548         u32 vmem_size;
 549         struct ssd1307fb_par *par;
 550         u8 *vmem;
 551         int ret;
 552
 553         if (!node) {
 554                 dev_err(&client->dev, "No device tree data found!\n");
 555                 return -EINVAL;
 556         }
 557
 558         info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev);
 559         if (!info) {
 560                 dev_err(&client->dev, "Couldn't allocate framebuffer.\n");
 561                 return -ENOMEM;
 562         }
 563
 564         par = info->par;
 565         par->info = info;
 566         par->client = client;
 567
 568         par->device_info = of_device_get_match_data(&client->dev);
 569
 570         par->reset = devm_gpiod_get_optional(&client->dev, "reset",
 571                                              GPIOD_OUT_LOW);
 572         if (IS_ERR(par->reset)) {
 573                 dev_err(&client->dev, "failed to get reset gpio: %ld\n",
 574                         PTR_ERR(par->reset));
 575                 ret = PTR_ERR(par->reset);
 576                 goto fb_alloc_error;
 577         }
 578
 579         par->vbat_reg = devm_regulator_get_optional(&client->dev, "vbat");
 580         if (IS_ERR(par->vbat_reg)) {
 581                 ret = PTR_ERR(par->vbat_reg);
 582                 if (ret == -ENODEV) {
 583                         par->vbat_reg = NULL;
 584                 } else {
 585                         dev_err(&client->dev, "failed to get VBAT regulator: %d\n",
 586                                 ret);
 587                         goto fb_alloc_error;
 588                 }
 589         }
 590
 591         if (of_property_read_u32(node, "solomon,width", &par->width))
 592                 par->width = 96;
 593
 594         if (of_property_read_u32(node, "solomon,height", &par->height))
 595                 par->height = 16;
 596
 597         if (of_property_read_u32(node, "solomon,page-offset", &par->page_offset))
 598                 par->page_offset = 1;
 599
 600         if (of_property_read_u32(node, "solomon,com-offset", &par->com_offset))
 601                 par->com_offset = 0;
 602
 603         if (of_property_read_u32(node, "solomon,prechargep1", &par->prechargep1))
 604                 par->prechargep1 = 2;
 605
 606         if (of_property_read_u32(node, "solomon,prechargep2", &par->prechargep2))
 607                 par->prechargep2 = 2;
 608
 609         par->seg_remap = !of_property_read_bool(node, "solomon,segment-no-remap");
 610         par->com_seq = of_property_read_bool(node, "solomon,com-seq");
 611         par->com_lrremap = of_property_read_bool(node, "solomon,com-lrremap");
 612         par->com_invdir = of_property_read_bool(node, "solomon,com-invdir");
 613
 614         par->contrast = 127;
 615         par->vcomh = par->device_info->default_vcomh;
 616
 617         /* Setup display timing */
 618         par->dclk_div = par->device_info->default_dclk_div;
 619         par->dclk_frq = par->device_info->default_dclk_frq;
 620
 621         vmem_size = par->width * par->height / 8;
 622
 623         vmem = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
 624                                         get_order(vmem_size));
 625         if (!vmem) {
 626                 dev_err(&client->dev, "Couldn't allocate graphical memory.\n");
 627                 ret = -ENOMEM;
 628                 goto fb_alloc_error;
 629         }
 630
 631         ssd1307fb_defio = devm_kzalloc(&client->dev, sizeof(*ssd1307fb_defio),
 632                                        GFP_KERNEL);
 633         if (!ssd1307fb_defio) {
 634                 dev_err(&client->dev, "Couldn't allocate deferred io.\n");
 635                 ret = -ENOMEM;
 636                 goto fb_alloc_error;
 637         }
 638
 639         ssd1307fb_defio->delay = HZ / refreshrate;
 640         ssd1307fb_defio->deferred_io = ssd1307fb_deferred_io;
 641
 642         info->fbops = &ssd1307fb_ops;
 643         info->fix = ssd1307fb_fix;
 644         info->fix.line_length = par->width / 8;
 645         info->fbdefio = ssd1307fb_defio;
 646
 647         info->var = ssd1307fb_var;
 648         info->var.xres = par->width;
 649         info->var.xres_virtual = par->width;
 650         info->var.yres = par->height;
 651         info->var.yres_virtual = par->height;
 652
 653         info->var.red.length = 1;
 654         info->var.red.offset = 0;
 655         info->var.green.length = 1;
 656         info->var.green.offset = 0;
 657         info->var.blue.length = 1;
 658         info->var.blue.offset = 0;
 659
 660         info->screen_base = (u8 __force __iomem *)vmem;
 661         info->fix.smem_start = __pa(vmem);
 662         info->fix.smem_len = vmem_size;
 663
 664         fb_deferred_io_init(info);
 665
 666         i2c_set_clientdata(client, info);
 667
 668         if (par->reset) {
 669                 /* Reset the screen */
 670                 gpiod_set_value_cansleep(par->reset, 0);
 671                 udelay(4);
 672                 gpiod_set_value_cansleep(par->reset, 1);
 673                 udelay(4);
 674         }
 675
 676         if (par->vbat_reg) {
 677                 ret = regulator_enable(par->vbat_reg);
 678                 if (ret) {
 679                         dev_err(&client->dev, "failed to enable VBAT: %d\n",
 680                                 ret);
 681                         goto reset_oled_error;
 682                 }
 683         }
 684
 685         ret = ssd1307fb_init(par);
 686         if (ret)
 687                 goto regulator_enable_error;
 688
 689         ret = register_framebuffer(info);
 690         if (ret) {
 691                 dev_err(&client->dev, "Couldn't register the framebuffer\n");
 692                 goto panel_init_error;
 693         }
 694
 695         snprintf(bl_name, sizeof(bl_name), "ssd1307fb%d", info->node);
 696         bl = backlight_device_register(bl_name, &client->dev, par,
 697                                        &ssd1307fb_bl_ops, NULL);
 698         if (IS_ERR(bl)) {
 699                 ret = PTR_ERR(bl);
 700                 dev_err(&client->dev, "unable to register backlight device: %d\n",
 701                         ret);
 702                 goto bl_init_error;
 703         }
 704
 705         bl->props.brightness = par->contrast;
 706         bl->props.max_brightness = MAX_CONTRAST;
 707         info->bl_dev = bl;
 708
 709         dev_info(&client->dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);
 710
 711         return 0;
 712
 713 bl_init_error:
 714         unregister_framebuffer(info);
 715 panel_init_error:
 716         if (par->device_info->need_pwm) {
 717                 pwm_disable(par->pwm);
 718                 pwm_put(par->pwm);
 719         };
 720 regulator_enable_error:
 721         if (par->vbat_reg)
 722                 regulator_disable(par->vbat_reg);
 723 reset_oled_error:
 724         fb_deferred_io_cleanup(info);
 725 fb_alloc_error:
 726         framebuffer_release(info);
 727         return ret;
 728 }
 729
 730 static int ssd1307fb_remove(struct i2c_client *client)
 731 {
 732         struct fb_info *info = i2c_get_clientdata(client);
 733         struct ssd1307fb_par *par = info->par;
 734
 735         ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);
 736
 737         backlight_device_unregister(info->bl_dev);
 738
 739         unregister_framebuffer(info);
 740         if (par->device_info->need_pwm) {
 741                 pwm_disable(par->pwm);
 742                 pwm_put(par->pwm);
 743         };
 744         fb_deferred_io_cleanup(info);
 745         __free_pages(__va(info->fix.smem_start), get_order(info->fix.smem_len));
 746         framebuffer_release(info);
 747
 748         return 0;
 749 }
 750
 751 static const struct i2c_device_id ssd1307fb_i2c_id[] = {
 752         { "ssd1305fb", 0 },
 753         { "ssd1306fb", 0 },
 754         { "ssd1307fb", 0 },
 755         { "ssd1309fb", 0 },
 756         { }
 757 };
 758 MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);
 759
 760 static struct i2c_driver ssd1307fb_driver = {
 761         .probe = ssd1307fb_probe,
 762         .remove = ssd1307fb_remove,
 763         .id_table = ssd1307fb_i2c_id,
 764         .driver = {
 765                 .name = "ssd1307fb",
 766                 .of_match_table = ssd1307fb_of_match,
 767         },
 768 };
 769
 770 module_i2c_driver(ssd1307fb_driver);
 771
 772 MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller");
 773 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 774 MODULE_LICENSE("GPL");