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/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/i2c.h>
  12 #include <linux/fb.h>
  13 #include <linux/uaccess.h>
  14 #include <linux/of_device.h>
  15 #include <linux/of_gpio.h>
  16 #include <linux/pwm.h>
  17 #include <linux/delay.h>
  18
  19 #define SSD1307FB_DATA                  0x40
  20 #define SSD1307FB_COMMAND               0x80
  21
  22 #define SSD1307FB_SET_ADDRESS_MODE      0x20
  23 #define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL   (0x00)
  24 #define SSD1307FB_SET_ADDRESS_MODE_VERTICAL     (0x01)
  25 #define SSD1307FB_SET_ADDRESS_MODE_PAGE         (0x02)
  26 #define SSD1307FB_SET_COL_RANGE         0x21
  27 #define SSD1307FB_SET_PAGE_RANGE        0x22
  28 #define SSD1307FB_CONTRAST              0x81
  29 #define SSD1307FB_CHARGE_PUMP           0x8d
  30 #define SSD1307FB_SEG_REMAP_ON          0xa1
  31 #define SSD1307FB_DISPLAY_OFF           0xae
  32 #define SSD1307FB_SET_MULTIPLEX_RATIO   0xa8
  33 #define SSD1307FB_DISPLAY_ON            0xaf
  34 #define SSD1307FB_START_PAGE_ADDRESS    0xb0
  35 #define SSD1307FB_SET_DISPLAY_OFFSET    0xd3
  36 #define SSD1307FB_SET_CLOCK_FREQ        0xd5
  37 #define SSD1307FB_SET_PRECHARGE_PERIOD  0xd9
  38 #define SSD1307FB_SET_COM_PINS_CONFIG   0xda
  39 #define SSD1307FB_SET_VCOMH             0xdb
  40
  41 struct ssd1307fb_par;
  42
  43 struct ssd1307fb_ops {
  44         int (*init)(struct ssd1307fb_par *);
  45         int (*remove)(struct ssd1307fb_par *);
  46 };
  47
  48 struct ssd1307fb_par {
  49         struct i2c_client *client;
  50         u32 height;
  51         struct fb_info *info;
  52         struct ssd1307fb_ops *ops;
  53         u32 page_offset;
  54         struct pwm_device *pwm;
  55         u32 pwm_period;
  56         int reset;
  57         u32 width;
  58 };
  59
  60 struct ssd1307fb_array {
  61         u8      type;
  62         u8      data[0];
  63 };
  64
  65 static struct fb_fix_screeninfo ssd1307fb_fix = {
  66         .id             = "Solomon SSD1307",
  67         .type           = FB_TYPE_PACKED_PIXELS,
  68         .visual         = FB_VISUAL_MONO10,
  69         .xpanstep       = 0,
  70         .ypanstep       = 0,
  71         .ywrapstep      = 0,
  72         .accel          = FB_ACCEL_NONE,
  73 };
  74
  75 static struct fb_var_screeninfo ssd1307fb_var = {
  76         .bits_per_pixel = 1,
  77 };
  78
  79 static struct ssd1307fb_array *ssd1307fb_alloc_array(u32 len, u8 type)
  80 {
  81         struct ssd1307fb_array *array;
  82
  83         array = kzalloc(sizeof(struct ssd1307fb_array) + len, GFP_KERNEL);
  84         if (!array)
  85                 return NULL;
  86
  87         array->type = type;
  88
  89         return array;
  90 }
  91
  92 static int ssd1307fb_write_array(struct i2c_client *client,
  93                                  struct ssd1307fb_array *array, u32 len)
  94 {
  95         int ret;
  96
  97         len += sizeof(struct ssd1307fb_array);
  98
  99         ret = i2c_master_send(client, (u8 *)array, len);
 100         if (ret != len) {
 101                 dev_err(&client->dev, "Couldn't send I2C command.\n");
 102                 return ret;
 103         }
 104
 105         return 0;
 106 }
 107
 108 static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
 109 {
 110         struct ssd1307fb_array *array;
 111         int ret;
 112
 113         array = ssd1307fb_alloc_array(1, SSD1307FB_COMMAND);
 114         if (!array)
 115                 return -ENOMEM;
 116
 117         array->data[0] = cmd;
 118
 119         ret = ssd1307fb_write_array(client, array, 1);
 120         kfree(array);
 121
 122         return ret;
 123 }
 124
 125 static void ssd1307fb_update_display(struct ssd1307fb_par *par)
 126 {
 127         struct ssd1307fb_array *array;
 128         u8 *vmem = par->info->screen_base;
 129         int i, j, k;
 130
 131         array = ssd1307fb_alloc_array(par->width * par->height / 8,
 132                                       SSD1307FB_DATA);
 133         if (!array)
 134                 return;
 135
 136         /*
 137          * The screen is divided in pages, each having a height of 8
 138          * pixels, and the width of the screen. When sending a byte of
 139          * data to the controller, it gives the 8 bits for the current
 140          * column. I.e, the first byte are the 8 bits of the first
 141          * column, then the 8 bits for the second column, etc.
 142          *
 143          *
 144          * Representation of the screen, assuming it is 5 bits
 145          * wide. Each letter-number combination is a bit that controls
 146          * one pixel.
 147          *
 148          * A0 A1 A2 A3 A4
 149          * B0 B1 B2 B3 B4
 150          * C0 C1 C2 C3 C4
 151          * D0 D1 D2 D3 D4
 152          * E0 E1 E2 E3 E4
 153          * F0 F1 F2 F3 F4
 154          * G0 G1 G2 G3 G4
 155          * H0 H1 H2 H3 H4
 156          *
 157          * If you want to update this screen, you need to send 5 bytes:
 158          *  (1) A0 B0 C0 D0 E0 F0 G0 H0
 159          *  (2) A1 B1 C1 D1 E1 F1 G1 H1
 160          *  (3) A2 B2 C2 D2 E2 F2 G2 H2
 161          *  (4) A3 B3 C3 D3 E3 F3 G3 H3
 162          *  (5) A4 B4 C4 D4 E4 F4 G4 H4
 163          */
 164
 165         for (i = 0; i < (par->height / 8); i++) {
 166                 for (j = 0; j < par->width; j++) {
 167                         u32 array_idx = i * par->width + j;
 168                         array->data[array_idx] = 0;
 169                         for (k = 0; k < 8; k++) {
 170                                 u32 page_length = par->width * i;
 171                                 u32 index = page_length + (par->width * k + j) / 8;
 172                                 u8 byte = *(vmem + index);
 173                                 u8 bit = byte & (1 << (j % 8));
 174                                 bit = bit >> (j % 8);
 175                                 array->data[array_idx] |= bit << k;
 176                         }
 177                 }
 178         }
 179
 180         ssd1307fb_write_array(par->client, array, par->width * par->height / 8);
 181         kfree(array);
 182 }
 183
 184
 185 static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
 186                 size_t count, loff_t *ppos)
 187 {
 188         struct ssd1307fb_par *par = info->par;
 189         unsigned long total_size;
 190         unsigned long p = *ppos;
 191         u8 __iomem *dst;
 192
 193         total_size = info->fix.smem_len;
 194
 195         if (p > total_size)
 196                 return -EINVAL;
 197
 198         if (count + p > total_size)
 199                 count = total_size - p;
 200
 201         if (!count)
 202                 return -EINVAL;
 203
 204         dst = (void __force *) (info->screen_base + p);
 205
 206         if (copy_from_user(dst, buf, count))
 207                 return -EFAULT;
 208
 209         ssd1307fb_update_display(par);
 210
 211         *ppos += count;
 212
 213         return count;
 214 }
 215
 216 static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
 217 {
 218         struct ssd1307fb_par *par = info->par;
 219         sys_fillrect(info, rect);
 220         ssd1307fb_update_display(par);
 221 }
 222
 223 static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
 224 {
 225         struct ssd1307fb_par *par = info->par;
 226         sys_copyarea(info, area);
 227         ssd1307fb_update_display(par);
 228 }
 229
 230 static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image)
 231 {
 232         struct ssd1307fb_par *par = info->par;
 233         sys_imageblit(info, image);
 234         ssd1307fb_update_display(par);
 235 }
 236
 237 static struct fb_ops ssd1307fb_ops = {
 238         .owner          = THIS_MODULE,
 239         .fb_read        = fb_sys_read,
 240         .fb_write       = ssd1307fb_write,
 241         .fb_fillrect    = ssd1307fb_fillrect,
 242         .fb_copyarea    = ssd1307fb_copyarea,
 243         .fb_imageblit   = ssd1307fb_imageblit,
 244 };
 245
 246 static void ssd1307fb_deferred_io(struct fb_info *info,
 247                                 struct list_head *pagelist)
 248 {
 249         ssd1307fb_update_display(info->par);
 250 }
 251
 252 static struct fb_deferred_io ssd1307fb_defio = {
 253         .delay          = HZ,
 254         .deferred_io    = ssd1307fb_deferred_io,
 255 };
 256
 257 static int ssd1307fb_ssd1307_init(struct ssd1307fb_par *par)
 258 {
 259         int ret;
 260
 261         par->pwm = pwm_get(&par->client->dev, NULL);
 262         if (IS_ERR(par->pwm)) {
 263                 dev_err(&par->client->dev, "Could not get PWM from device tree!\n");
 264                 return PTR_ERR(par->pwm);
 265         }
 266
 267         par->pwm_period = pwm_get_period(par->pwm);
 268         /* Enable the PWM */
 269         pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);
 270         pwm_enable(par->pwm);
 271
 272         dev_dbg(&par->client->dev, "Using PWM%d with a %dns period.\n",
 273                 par->pwm->pwm, par->pwm_period);
 274
 275         /* Map column 127 of the OLED to segment 0 */
 276         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON);
 277         if (ret < 0)
 278                 return ret;
 279
 280         /* Turn on the display */
 281         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
 282         if (ret < 0)
 283                 return ret;
 284
 285         return 0;
 286 }
 287
 288 static int ssd1307fb_ssd1307_remove(struct ssd1307fb_par *par)
 289 {
 290         pwm_disable(par->pwm);
 291         pwm_put(par->pwm);
 292         return 0;
 293 }
 294
 295 static struct ssd1307fb_ops ssd1307fb_ssd1307_ops = {
 296         .init   = ssd1307fb_ssd1307_init,
 297         .remove = ssd1307fb_ssd1307_remove,
 298 };
 299
 300 static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par)
 301 {
 302         int ret;
 303
 304         /* Set initial contrast */
 305         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
 306         if (ret < 0)
 307                 return ret;
 308
 309         ret = ssd1307fb_write_cmd(par->client, 0x7f);
 310         if (ret < 0)
 311                 return ret;
 312
 313         /* Set COM direction */
 314         ret = ssd1307fb_write_cmd(par->client, 0xc8);
 315         if (ret < 0)
 316                 return ret;
 317
 318         /* Set segment re-map */
 319         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON);
 320         if (ret < 0)
 321                 return ret;
 322
 323         /* Set multiplex ratio value */
 324         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO);
 325         if (ret < 0)
 326                 return ret;
 327
 328         ret = ssd1307fb_write_cmd(par->client, par->height - 1);
 329         if (ret < 0)
 330                 return ret;
 331
 332         /* set display offset value */
 333         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET);
 334         if (ret < 0)
 335                 return ret;
 336
 337         ret = ssd1307fb_write_cmd(par->client, 0x20);
 338         if (ret < 0)
 339                 return ret;
 340
 341         /* Set clock frequency */
 342         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ);
 343         if (ret < 0)
 344                 return ret;
 345
 346         ret = ssd1307fb_write_cmd(par->client, 0xf0);
 347         if (ret < 0)
 348                 return ret;
 349
 350         /* Set precharge period in number of ticks from the internal clock */
 351         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD);
 352         if (ret < 0)
 353                 return ret;
 354
 355         ret = ssd1307fb_write_cmd(par->client, 0x22);
 356         if (ret < 0)
 357                 return ret;
 358
 359         /* Set COM pins configuration */
 360         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG);
 361         if (ret < 0)
 362                 return ret;
 363
 364         ret = ssd1307fb_write_cmd(par->client, 0x22);
 365         if (ret < 0)
 366                 return ret;
 367
 368         /* Set VCOMH */
 369         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH);
 370         if (ret < 0)
 371                 return ret;
 372
 373         ret = ssd1307fb_write_cmd(par->client, 0x49);
 374         if (ret < 0)
 375                 return ret;
 376
 377         /* Turn on the DC-DC Charge Pump */
 378         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);
 379         if (ret < 0)
 380                 return ret;
 381
 382         ret = ssd1307fb_write_cmd(par->client, 0x14);
 383         if (ret < 0)
 384                 return ret;
 385
 386         /* Switch to horizontal addressing mode */
 387         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE);
 388         if (ret < 0)
 389                 return ret;
 390
 391         ret = ssd1307fb_write_cmd(par->client,
 392                                   SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
 393         if (ret < 0)
 394                 return ret;
 395
 396         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
 397         if (ret < 0)
 398                 return ret;
 399
 400         ret = ssd1307fb_write_cmd(par->client, 0x0);
 401         if (ret < 0)
 402                 return ret;
 403
 404         ret = ssd1307fb_write_cmd(par->client, par->width - 1);
 405         if (ret < 0)
 406                 return ret;
 407
 408         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
 409         if (ret < 0)
 410                 return ret;
 411
 412         ret = ssd1307fb_write_cmd(par->client, 0x0);
 413         if (ret < 0)
 414                 return ret;
 415
 416         ret = ssd1307fb_write_cmd(par->client,
 417                                   par->page_offset + (par->height / 8) - 1);
 418         if (ret < 0)
 419                 return ret;
 420
 421         /* Turn on the display */
 422         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
 423         if (ret < 0)
 424                 return ret;
 425
 426         return 0;
 427 }
 428
 429 static struct ssd1307fb_ops ssd1307fb_ssd1306_ops = {
 430         .init   = ssd1307fb_ssd1306_init,
 431 };
 432
 433 static const struct of_device_id ssd1307fb_of_match[] = {
 434         {
 435                 .compatible = "solomon,ssd1306fb-i2c",
 436                 .data = (void *)&ssd1307fb_ssd1306_ops,
 437         },
 438         {
 439                 .compatible = "solomon,ssd1307fb-i2c",
 440                 .data = (void *)&ssd1307fb_ssd1307_ops,
 441         },
 442         {},
 443 };
 444 MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);
 445
 446 static int ssd1307fb_probe(struct i2c_client *client,
 447                            const struct i2c_device_id *id)
 448 {
 449         struct fb_info *info;
 450         struct device_node *node = client->dev.of_node;
 451         u32 vmem_size;
 452         struct ssd1307fb_par *par;
 453         u8 *vmem;
 454         int ret;
 455
 456         if (!node) {
 457                 dev_err(&client->dev, "No device tree data found!\n");
 458                 return -EINVAL;
 459         }
 460
 461         info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev);
 462         if (!info) {
 463                 dev_err(&client->dev, "Couldn't allocate framebuffer.\n");
 464                 return -ENOMEM;
 465         }
 466
 467         par = info->par;
 468         par->info = info;
 469         par->client = client;
 470
 471         par->ops = (struct ssd1307fb_ops *)of_match_device(ssd1307fb_of_match,
 472                                                            &client->dev)->data;
 473
 474         par->reset = of_get_named_gpio(client->dev.of_node,
 475                                          "reset-gpios", 0);
 476         if (!gpio_is_valid(par->reset)) {
 477                 ret = -EINVAL;
 478                 goto fb_alloc_error;
 479         }
 480
 481         if (of_property_read_u32(node, "solomon,width", &par->width))
 482                 par->width = 96;
 483
 484         if (of_property_read_u32(node, "solomon,height", &par->height))
 485                 par->height = 16;
 486
 487         if (of_property_read_u32(node, "solomon,page-offset", &par->page_offset))
 488                 par->page_offset = 1;
 489
 490         vmem_size = par->width * par->height / 8;
 491
 492         vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL);
 493         if (!vmem) {
 494                 dev_err(&client->dev, "Couldn't allocate graphical memory.\n");
 495                 ret = -ENOMEM;
 496                 goto fb_alloc_error;
 497         }
 498
 499         info->fbops = &ssd1307fb_ops;
 500         info->fix = ssd1307fb_fix;
 501         info->fix.line_length = par->width / 8;
 502         info->fbdefio = &ssd1307fb_defio;
 503
 504         info->var = ssd1307fb_var;
 505         info->var.xres = par->width;
 506         info->var.xres_virtual = par->width;
 507         info->var.yres = par->height;
 508         info->var.yres_virtual = par->height;
 509
 510         info->var.red.length = 1;
 511         info->var.red.offset = 0;
 512         info->var.green.length = 1;
 513         info->var.green.offset = 0;
 514         info->var.blue.length = 1;
 515         info->var.blue.offset = 0;
 516
 517         info->screen_base = (u8 __force __iomem *)vmem;
 518         info->fix.smem_start = (unsigned long)vmem;
 519         info->fix.smem_len = vmem_size;
 520
 521         fb_deferred_io_init(info);
 522
 523         ret = devm_gpio_request_one(&client->dev, par->reset,
 524                                     GPIOF_OUT_INIT_HIGH,
 525                                     "oled-reset");
 526         if (ret) {
 527                 dev_err(&client->dev,
 528                         "failed to request gpio %d: %d\n",
 529                         par->reset, ret);
 530                 goto reset_oled_error;
 531         }
 532
 533         i2c_set_clientdata(client, info);
 534
 535         /* Reset the screen */
 536         gpio_set_value(par->reset, 0);
 537         udelay(4);
 538         gpio_set_value(par->reset, 1);
 539         udelay(4);
 540
 541         if (par->ops->init) {
 542                 ret = par->ops->init(par);
 543                 if (ret)
 544                         goto reset_oled_error;
 545         }
 546
 547         ret = register_framebuffer(info);
 548         if (ret) {
 549                 dev_err(&client->dev, "Couldn't register the framebuffer\n");
 550                 goto panel_init_error;
 551         }
 552
 553         dev_info(&client->dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);
 554
 555         return 0;
 556
 557 panel_init_error:
 558         if (par->ops->remove)
 559                 par->ops->remove(par);
 560 reset_oled_error:
 561         fb_deferred_io_cleanup(info);
 562 fb_alloc_error:
 563         framebuffer_release(info);
 564         return ret;
 565 }
 566
 567 static int ssd1307fb_remove(struct i2c_client *client)
 568 {
 569         struct fb_info *info = i2c_get_clientdata(client);
 570         struct ssd1307fb_par *par = info->par;
 571
 572         unregister_framebuffer(info);
 573         if (par->ops->remove)
 574                 par->ops->remove(par);
 575         fb_deferred_io_cleanup(info);
 576         framebuffer_release(info);
 577
 578         return 0;
 579 }
 580
 581 static const struct i2c_device_id ssd1307fb_i2c_id[] = {
 582         { "ssd1306fb", 0 },
 583         { "ssd1307fb", 0 },
 584         { }
 585 };
 586 MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);
 587
 588 static struct i2c_driver ssd1307fb_driver = {
 589         .probe = ssd1307fb_probe,
 590         .remove = ssd1307fb_remove,
 591         .id_table = ssd1307fb_i2c_id,
 592         .driver = {
 593                 .name = "ssd1307fb",
 594                 .of_match_table = ssd1307fb_of_match,
 595                 .owner = THIS_MODULE,
 596         },
 597 };
 598
 599 module_i2c_driver(ssd1307fb_driver);
 600
 601 MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller");
 602 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 603 MODULE_LICENSE("GPL");