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