drivers/video/hecubafb.c

   1 /*
   2  * linux/drivers/video/hecubafb.c -- FB driver for Hecuba controller
   3  *
   4  * Copyright (C) 2006, Jaya Kumar
   5  * This work was sponsored by CIS(M) Sdn Bhd
   6  *
   7  * This file is subject to the terms and conditions of the GNU General Public
   8  * License. See the file COPYING in the main directory of this archive for
   9  * more details.
  10  *
  11  * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
  12  * This work was possible because of apollo display code from E-Ink's website
  13  * http://support.eink.com/community
  14  * All information used to write this code is from public material made
  15  * available by E-Ink on its support site. Some commands such as 0xA4
  16  * were found by looping through cmd=0x00 thru 0xFF and supplying random
  17  * values. There are other commands that the display is capable of,
  18  * beyond the 5 used here but they are more complex.
  19  *
  20  * This driver is written to be used with the Hecuba display controller
  21  * board, and tested with the EInk 800x600 display in 1 bit mode.
  22  * The interface between Hecuba and the host is TTL based GPIO. The
  23  * GPIO requirements are 8 writable data lines and 6 lines for control.
  24  * Only 4 of the controls are actually used here but 6 for future use.
  25  * The driver requires the IO addresses for data and control GPIO at
  26  * load time. It is also possible to use this display with a standard
  27  * PC parallel port.
  28  *
  29  * General notes:
  30  * - User must set hecubafb_enable=1 to enable it
  31  * - User must set dio_addr=0xIOADDR cio_addr=0xIOADDR c2io_addr=0xIOADDR
  32  *
  33  */
  34
  35 #include <linux/module.h>
  36 #include <linux/kernel.h>
  37 #include <linux/errno.h>
  38 #include <linux/string.h>
  39 #include <linux/mm.h>
  40 #include <linux/slab.h>
  41 #include <linux/vmalloc.h>
  42 #include <linux/delay.h>
  43 #include <linux/interrupt.h>
  44 #include <linux/fb.h>
  45 #include <linux/init.h>
  46 #include <linux/platform_device.h>
  47 #include <linux/list.h>
  48 #include <linux/uaccess.h>
  49
  50 /* Apollo controller specific defines */
  51 #define APOLLO_START_NEW_IMG    0xA0
  52 #define APOLLO_STOP_IMG_DATA    0xA1
  53 #define APOLLO_DISPLAY_IMG      0xA2
  54 #define APOLLO_ERASE_DISPLAY    0xA3
  55 #define APOLLO_INIT_DISPLAY     0xA4
  56
  57 /* Hecuba interface specific defines */
  58 /* WUP is inverted, CD is inverted, DS is inverted */
  59 #define HCB_NWUP_BIT    0x01
  60 #define HCB_NDS_BIT     0x02
  61 #define HCB_RW_BIT      0x04
  62 #define HCB_NCD_BIT     0x08
  63 #define HCB_ACK_BIT     0x80
  64
  65 /* Display specific information */
  66 #define DPY_W 600
  67 #define DPY_H 800
  68
  69 struct hecubafb_par {
  70         unsigned long dio_addr;
  71         unsigned long cio_addr;
  72         unsigned long c2io_addr;
  73         unsigned char ctl;
  74         struct fb_info *info;
  75         unsigned int irq;
  76 };
  77
  78 static struct fb_fix_screeninfo hecubafb_fix __devinitdata = {
  79         .id =           "hecubafb",
  80         .type =         FB_TYPE_PACKED_PIXELS,
  81         .visual =       FB_VISUAL_MONO01,
  82         .xpanstep =     0,
  83         .ypanstep =     0,
  84         .ywrapstep =    0,
  85         .accel =        FB_ACCEL_NONE,
  86 };
  87
  88 static struct fb_var_screeninfo hecubafb_var __devinitdata = {
  89         .xres           = DPY_W,
  90         .yres           = DPY_H,
  91         .xres_virtual   = DPY_W,
  92         .yres_virtual   = DPY_H,
  93         .bits_per_pixel = 1,
  94         .nonstd         = 1,
  95 };
  96
  97 static unsigned long dio_addr;
  98 static unsigned long cio_addr;
  99 static unsigned long c2io_addr;
 100 static unsigned long splashval;
 101 static unsigned int nosplash;
 102 static unsigned int hecubafb_enable;
 103 static unsigned int irq;
 104
 105 static DECLARE_WAIT_QUEUE_HEAD(hecubafb_waitq);
 106
 107 static void hcb_set_ctl(struct hecubafb_par *par)
 108 {
 109         outb(par->ctl, par->cio_addr);
 110 }
 111
 112 static unsigned char hcb_get_ctl(struct hecubafb_par *par)
 113 {
 114         return inb(par->c2io_addr);
 115 }
 116
 117 static void hcb_set_data(struct hecubafb_par *par, unsigned char value)
 118 {
 119         outb(value, par->dio_addr);
 120 }
 121
 122 static int __devinit apollo_init_control(struct hecubafb_par *par)
 123 {
 124         unsigned char ctl;
 125         /* for init, we want the following setup to be set:
 126         WUP = lo
 127         ACK = hi
 128         DS = hi
 129         RW = hi
 130         CD = lo
 131         */
 132
 133         /* write WUP to lo, DS to hi, RW to hi, CD to lo */
 134         par->ctl = HCB_NWUP_BIT | HCB_RW_BIT | HCB_NCD_BIT ;
 135         par->ctl &= ~HCB_NDS_BIT;
 136         hcb_set_ctl(par);
 137
 138         /* check ACK is not lo */
 139         ctl = hcb_get_ctl(par);
 140         if ((ctl & HCB_ACK_BIT)) {
 141                 printk(KERN_ERR "Fail because ACK is already low\n");
 142                 return -ENXIO;
 143         }
 144
 145         return 0;
 146 }
 147
 148 static void hcb_wait_for_ack(struct hecubafb_par *par)
 149 {
 150
 151         int timeout;
 152         unsigned char ctl;
 153
 154         timeout=500;
 155         do {
 156                 ctl = hcb_get_ctl(par);
 157                 if ((ctl & HCB_ACK_BIT))
 158                         return;
 159                 udelay(1);
 160         } while (timeout--);
 161         printk(KERN_ERR "timed out waiting for ack\n");
 162 }
 163
 164 static void hcb_wait_for_ack_clear(struct hecubafb_par *par)
 165 {
 166
 167         int timeout;
 168         unsigned char ctl;
 169
 170         timeout=500;
 171         do {
 172                 ctl = hcb_get_ctl(par);
 173                 if (!(ctl & HCB_ACK_BIT))
 174                         return;
 175                 udelay(1);
 176         } while (timeout--);
 177         printk(KERN_ERR "timed out waiting for clear\n");
 178 }
 179
 180 static void apollo_send_data(struct hecubafb_par *par, unsigned char data)
 181 {
 182         /* set data */
 183         hcb_set_data(par, data);
 184
 185         /* set DS low */
 186         par->ctl |= HCB_NDS_BIT;
 187         hcb_set_ctl(par);
 188
 189         hcb_wait_for_ack(par);
 190
 191         /* set DS hi */
 192         par->ctl &= ~(HCB_NDS_BIT);
 193         hcb_set_ctl(par);
 194
 195         hcb_wait_for_ack_clear(par);
 196 }
 197
 198 static void apollo_send_command(struct hecubafb_par *par, unsigned char data)
 199 {
 200         /* command so set CD to high */
 201         par->ctl &= ~(HCB_NCD_BIT);
 202         hcb_set_ctl(par);
 203
 204         /* actually strobe with command */
 205         apollo_send_data(par, data);
 206
 207         /* clear CD back to low */
 208         par->ctl |= (HCB_NCD_BIT);
 209         hcb_set_ctl(par);
 210 }
 211
 212 /* main hecubafb functions */
 213
 214 static void hecubafb_dpy_update(struct hecubafb_par *par)
 215 {
 216         int i;
 217         unsigned char *buf = (unsigned char __force *)par->info->screen_base;
 218
 219         apollo_send_command(par, 0xA0);
 220
 221         for (i=0; i < (DPY_W*DPY_H/8); i++) {
 222                 apollo_send_data(par, *(buf++));
 223         }
 224
 225         apollo_send_command(par, 0xA1);
 226         apollo_send_command(par, 0xA2);
 227 }
 228
 229 /* this is called back from the deferred io workqueue */
 230 static void hecubafb_dpy_deferred_io(struct fb_info *info,
 231                                 struct list_head *pagelist)
 232 {
 233         hecubafb_dpy_update(info->par);
 234 }
 235
 236 static void hecubafb_fillrect(struct fb_info *info,
 237                                    const struct fb_fillrect *rect)
 238 {
 239         struct hecubafb_par *par = info->par;
 240
 241         sys_fillrect(info, rect);
 242
 243         hecubafb_dpy_update(par);
 244 }
 245
 246 static void hecubafb_copyarea(struct fb_info *info,
 247                                    const struct fb_copyarea *area)
 248 {
 249         struct hecubafb_par *par = info->par;
 250
 251         sys_copyarea(info, area);
 252
 253         hecubafb_dpy_update(par);
 254 }
 255
 256 static void hecubafb_imageblit(struct fb_info *info,
 257                                 const struct fb_image *image)
 258 {
 259         struct hecubafb_par *par = info->par;
 260
 261         sys_imageblit(info, image);
 262
 263         hecubafb_dpy_update(par);
 264 }
 265
 266 /*
 267  * this is the slow path from userspace. they can seek and write to
 268  * the fb. it's inefficient to do anything less than a full screen draw
 269  */
 270 static ssize_t hecubafb_write(struct fb_info *info, const char __user *buf,
 271                                 size_t count, loff_t *ppos)
 272 {
 273         unsigned long p;
 274         int err=-EINVAL;
 275         struct hecubafb_par *par;
 276         unsigned int xres;
 277         unsigned int fbmemlength;
 278
 279         p = *ppos;
 280         par = info->par;
 281         xres = info->var.xres;
 282         fbmemlength = (xres * info->var.yres)/8;
 283
 284         if (p > fbmemlength)
 285                 return -ENOSPC;
 286
 287         err = 0;
 288         if ((count + p) > fbmemlength) {
 289                 count = fbmemlength - p;
 290                 err = -ENOSPC;
 291         }
 292
 293         if (count) {
 294                 char *base_addr;
 295
 296                 base_addr = (char __force *)info->screen_base;
 297                 count -= copy_from_user(base_addr + p, buf, count);
 298                 *ppos += count;
 299                 err = -EFAULT;
 300         }
 301
 302         hecubafb_dpy_update(par);
 303
 304         if (count)
 305                 return count;
 306
 307         return err;
 308 }
 309
 310 static struct fb_ops hecubafb_ops = {
 311         .owner          = THIS_MODULE,
 312         .fb_read        = fb_sys_read,
 313         .fb_write       = hecubafb_write,
 314         .fb_fillrect    = hecubafb_fillrect,
 315         .fb_copyarea    = hecubafb_copyarea,
 316         .fb_imageblit   = hecubafb_imageblit,
 317 };
 318
 319 static struct fb_deferred_io hecubafb_defio = {
 320         .delay          = HZ,
 321         .deferred_io    = hecubafb_dpy_deferred_io,
 322 };
 323
 324 static int __devinit hecubafb_probe(struct platform_device *dev)
 325 {
 326         struct fb_info *info;
 327         int retval = -ENOMEM;
 328         int videomemorysize;
 329         unsigned char *videomemory;
 330         struct hecubafb_par *par;
 331
 332         videomemorysize = (DPY_W*DPY_H)/8;
 333
 334         if (!(videomemory = vmalloc(videomemorysize)))
 335                 return retval;
 336
 337         memset(videomemory, 0, videomemorysize);
 338
 339         info = framebuffer_alloc(sizeof(struct hecubafb_par), &dev->dev);
 340         if (!info)
 341                 goto err;
 342
 343         info->screen_base = (char __iomem *) videomemory;
 344         info->fbops = &hecubafb_ops;
 345
 346         info->var = hecubafb_var;
 347         info->fix = hecubafb_fix;
 348         info->fix.smem_len = videomemorysize;
 349         par = info->par;
 350         par->info = info;
 351
 352         if (!dio_addr || !cio_addr || !c2io_addr) {
 353                 printk(KERN_WARNING "no IO addresses supplied\n");
 354                 goto err1;
 355         }
 356         par->dio_addr = dio_addr;
 357         par->cio_addr = cio_addr;
 358         par->c2io_addr = c2io_addr;
 359         info->flags = FBINFO_FLAG_DEFAULT;
 360
 361         info->fbdefio = &hecubafb_defio;
 362         fb_deferred_io_init(info);
 363
 364         retval = register_framebuffer(info);
 365         if (retval < 0)
 366                 goto err1;
 367         platform_set_drvdata(dev, info);
 368
 369         printk(KERN_INFO
 370                "fb%d: Hecuba frame buffer device, using %dK of video memory\n",
 371                info->node, videomemorysize >> 10);
 372
 373         /* this inits the dpy */
 374         apollo_init_control(par);
 375
 376         apollo_send_command(par, APOLLO_INIT_DISPLAY);
 377         apollo_send_data(par, 0x81);
 378
 379         /* have to wait while display resets */
 380         udelay(1000);
 381
 382         /* if we were told to splash the screen, we just clear it */
 383         if (!nosplash) {
 384                 apollo_send_command(par, APOLLO_ERASE_DISPLAY);
 385                 apollo_send_data(par, splashval);
 386         }
 387
 388         return 0;
 389 err1:
 390         framebuffer_release(info);
 391 err:
 392         vfree(videomemory);
 393         return retval;
 394 }
 395
 396 static int __devexit hecubafb_remove(struct platform_device *dev)
 397 {
 398         struct fb_info *info = platform_get_drvdata(dev);
 399
 400         if (info) {
 401                 fb_deferred_io_cleanup(info);
 402                 unregister_framebuffer(info);
 403                 vfree((void __force *)info->screen_base);
 404                 framebuffer_release(info);
 405         }
 406         return 0;
 407 }
 408
 409 static struct platform_driver hecubafb_driver = {
 410         .probe  = hecubafb_probe,
 411         .remove = hecubafb_remove,
 412         .driver = {
 413                 .name   = "hecubafb",
 414         },
 415 };
 416
 417 static struct platform_device *hecubafb_device;
 418
 419 static int __init hecubafb_init(void)
 420 {
 421         int ret;
 422
 423         if (!hecubafb_enable) {
 424                 printk(KERN_ERR "Use hecubafb_enable to enable the device\n");
 425                 return -ENXIO;
 426         }
 427
 428         ret = platform_driver_register(&hecubafb_driver);
 429         if (!ret) {
 430                 hecubafb_device = platform_device_alloc("hecubafb", 0);
 431                 if (hecubafb_device)
 432                         ret = platform_device_add(hecubafb_device);
 433                 else
 434                         ret = -ENOMEM;
 435
 436                 if (ret) {
 437                         platform_device_put(hecubafb_device);
 438                         platform_driver_unregister(&hecubafb_driver);
 439                 }
 440         }
 441         return ret;
 442
 443 }
 444
 445 static void __exit hecubafb_exit(void)
 446 {
 447         platform_device_unregister(hecubafb_device);
 448         platform_driver_unregister(&hecubafb_driver);
 449 }
 450
 451 module_param(nosplash, uint, 0);
 452 MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
 453 module_param(hecubafb_enable, uint, 0);
 454 MODULE_PARM_DESC(hecubafb_enable, "Enable communication with Hecuba board");
 455 module_param(dio_addr, ulong, 0);
 456 MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
 457 module_param(cio_addr, ulong, 0);
 458 MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
 459 module_param(c2io_addr, ulong, 0);
 460 MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
 461 module_param(splashval, ulong, 0);
 462 MODULE_PARM_DESC(splashval, "Splash pattern: 0x00 is black, 0x01 is white");
 463 module_param(irq, uint, 0);
 464 MODULE_PARM_DESC(irq, "IRQ for the Hecuba board");
 465
 466 module_init(hecubafb_init);
 467 module_exit(hecubafb_exit);
 468
 469 MODULE_DESCRIPTION("fbdev driver for Hecuba board");
 470 MODULE_AUTHOR("Jaya Kumar");
 471 MODULE_LICENSE("GPL");