drivers/video/hecubafb.c

   1 /*
   2  * linux/drivers/video/hecubafb.c -- FB driver for Hecuba/Apollo 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 architecture.
  21  * The actual display chip is called Apollo and the interface electronics
  22  * it needs is called Hecuba.
  23  *
  24  * It is intended to be architecture independent. A board specific driver
  25  * must be used to perform all the physical IO interactions. An example
  26  * is provided as n411.c
  27  *
  28  */
  29
  30 #include <linux/module.h>
  31 #include <linux/kernel.h>
  32 #include <linux/errno.h>
  33 #include <linux/string.h>
  34 #include <linux/mm.h>
  35 #include <linux/slab.h>
  36 #include <linux/vmalloc.h>
  37 #include <linux/delay.h>
  38 #include <linux/interrupt.h>
  39 #include <linux/fb.h>
  40 #include <linux/init.h>
  41 #include <linux/platform_device.h>
  42 #include <linux/list.h>
  43 #include <linux/uaccess.h>
  44
  45 #include <video/hecubafb.h>
  46
  47 /* Display specific information */
  48 #define DPY_W 600
  49 #define DPY_H 800
  50
  51 static struct fb_fix_screeninfo hecubafb_fix __devinitdata = {
  52         .id =           "hecubafb",
  53         .type =         FB_TYPE_PACKED_PIXELS,
  54         .visual =       FB_VISUAL_MONO01,
  55         .xpanstep =     0,
  56         .ypanstep =     0,
  57         .ywrapstep =    0,
  58         .line_length =  DPY_W,
  59         .accel =        FB_ACCEL_NONE,
  60 };
  61
  62 static struct fb_var_screeninfo hecubafb_var __devinitdata = {
  63         .xres           = DPY_W,
  64         .yres           = DPY_H,
  65         .xres_virtual   = DPY_W,
  66         .yres_virtual   = DPY_H,
  67         .bits_per_pixel = 1,
  68         .nonstd         = 1,
  69 };
  70
  71 /* main hecubafb functions */
  72
  73 static void apollo_send_data(struct hecubafb_par *par, unsigned char data)
  74 {
  75         /* set data */
  76         par->board->set_data(par, data);
  77
  78         /* set DS low */
  79         par->board->set_ctl(par, HCB_DS_BIT, 0);
  80
  81         /* wait for ack */
  82         par->board->wait_for_ack(par, 0);
  83
  84         /* set DS hi */
  85         par->board->set_ctl(par, HCB_DS_BIT, 1);
  86
  87         /* wait for ack to clear */
  88         par->board->wait_for_ack(par, 1);
  89 }
  90
  91 static void apollo_send_command(struct hecubafb_par *par, unsigned char data)
  92 {
  93         /* command so set CD to high */
  94         par->board->set_ctl(par, HCB_CD_BIT, 1);
  95
  96         /* actually strobe with command */
  97         apollo_send_data(par, data);
  98
  99         /* clear CD back to low */
 100         par->board->set_ctl(par, HCB_CD_BIT, 0);
 101 }
 102
 103 static void hecubafb_dpy_update(struct hecubafb_par *par)
 104 {
 105         int i;
 106         unsigned char *buf = (unsigned char __force *)par->info->screen_base;
 107
 108         apollo_send_command(par, APOLLO_START_NEW_IMG);
 109
 110         for (i=0; i < (DPY_W*DPY_H/8); i++) {
 111                 apollo_send_data(par, *(buf++));
 112         }
 113
 114         apollo_send_command(par, APOLLO_STOP_IMG_DATA);
 115         apollo_send_command(par, APOLLO_DISPLAY_IMG);
 116 }
 117
 118 /* this is called back from the deferred io workqueue */
 119 static void hecubafb_dpy_deferred_io(struct fb_info *info,
 120                                 struct list_head *pagelist)
 121 {
 122         hecubafb_dpy_update(info->par);
 123 }
 124
 125 static void hecubafb_fillrect(struct fb_info *info,
 126                                    const struct fb_fillrect *rect)
 127 {
 128         struct hecubafb_par *par = info->par;
 129
 130         sys_fillrect(info, rect);
 131
 132         hecubafb_dpy_update(par);
 133 }
 134
 135 static void hecubafb_copyarea(struct fb_info *info,
 136                                    const struct fb_copyarea *area)
 137 {
 138         struct hecubafb_par *par = info->par;
 139
 140         sys_copyarea(info, area);
 141
 142         hecubafb_dpy_update(par);
 143 }
 144
 145 static void hecubafb_imageblit(struct fb_info *info,
 146                                 const struct fb_image *image)
 147 {
 148         struct hecubafb_par *par = info->par;
 149
 150         sys_imageblit(info, image);
 151
 152         hecubafb_dpy_update(par);
 153 }
 154
 155 /*
 156  * this is the slow path from userspace. they can seek and write to
 157  * the fb. it's inefficient to do anything less than a full screen draw
 158  */
 159 static ssize_t hecubafb_write(struct fb_info *info, const char __user *buf,
 160                                 size_t count, loff_t *ppos)
 161 {
 162         struct hecubafb_par *par = info->par;
 163         unsigned long p = *ppos;
 164         void *dst;
 165         int err = 0;
 166         unsigned long total_size;
 167
 168         if (info->state != FBINFO_STATE_RUNNING)
 169                 return -EPERM;
 170
 171         total_size = info->fix.smem_len;
 172
 173         if (p > total_size)
 174                 return -EFBIG;
 175
 176         if (count > total_size) {
 177                 err = -EFBIG;
 178                 count = total_size;
 179         }
 180
 181         if (count + p > total_size) {
 182                 if (!err)
 183                         err = -ENOSPC;
 184
 185                 count = total_size - p;
 186         }
 187
 188         dst = (void __force *) (info->screen_base + p);
 189
 190         if (copy_from_user(dst, buf, count))
 191                 err = -EFAULT;
 192
 193         if  (!err)
 194                 *ppos += count;
 195
 196         hecubafb_dpy_update(par);
 197
 198         return (err) ? err : count;
 199 }
 200
 201 static struct fb_ops hecubafb_ops = {
 202         .owner          = THIS_MODULE,
 203         .fb_read        = fb_sys_read,
 204         .fb_write       = hecubafb_write,
 205         .fb_fillrect    = hecubafb_fillrect,
 206         .fb_copyarea    = hecubafb_copyarea,
 207         .fb_imageblit   = hecubafb_imageblit,
 208 };
 209
 210 static struct fb_deferred_io hecubafb_defio = {
 211         .delay          = HZ,
 212         .deferred_io    = hecubafb_dpy_deferred_io,
 213 };
 214
 215 static int __devinit hecubafb_probe(struct platform_device *dev)
 216 {
 217         struct fb_info *info;
 218         struct hecuba_board *board;
 219         int retval = -ENOMEM;
 220         int videomemorysize;
 221         unsigned char *videomemory;
 222         struct hecubafb_par *par;
 223
 224         /* pick up board specific routines */
 225         board = dev->dev.platform_data;
 226         if (!board)
 227                 return -EINVAL;
 228
 229         /* try to count device specific driver, if can't, platform recalls */
 230         if (!try_module_get(board->owner))
 231                 return -ENODEV;
 232
 233         videomemorysize = (DPY_W*DPY_H)/8;
 234
 235         if (!(videomemory = vmalloc(videomemorysize)))
 236                 return retval;
 237
 238         memset(videomemory, 0, videomemorysize);
 239
 240         info = framebuffer_alloc(sizeof(struct hecubafb_par), &dev->dev);
 241         if (!info)
 242                 goto err_fballoc;
 243
 244         info->screen_base = (char __force __iomem *)videomemory;
 245         info->fbops = &hecubafb_ops;
 246
 247         info->var = hecubafb_var;
 248         info->fix = hecubafb_fix;
 249         info->fix.smem_len = videomemorysize;
 250         par = info->par;
 251         par->info = info;
 252         par->board = board;
 253         par->send_command = apollo_send_command;
 254         par->send_data = apollo_send_data;
 255
 256         info->flags = FBINFO_FLAG_DEFAULT;
 257
 258         info->fbdefio = &hecubafb_defio;
 259         fb_deferred_io_init(info);
 260
 261         retval = register_framebuffer(info);
 262         if (retval < 0)
 263                 goto err_fbreg;
 264         platform_set_drvdata(dev, info);
 265
 266         printk(KERN_INFO
 267                "fb%d: Hecuba frame buffer device, using %dK of video memory\n",
 268                info->node, videomemorysize >> 10);
 269
 270         /* this inits the dpy */
 271         retval = par->board->init(par);
 272         if (retval < 0)
 273                 goto err_fbreg;
 274
 275         return 0;
 276 err_fbreg:
 277         framebuffer_release(info);
 278 err_fballoc:
 279         vfree(videomemory);
 280         module_put(board->owner);
 281         return retval;
 282 }
 283
 284 static int __devexit hecubafb_remove(struct platform_device *dev)
 285 {
 286         struct fb_info *info = platform_get_drvdata(dev);
 287
 288         if (info) {
 289                 struct hecubafb_par *par = info->par;
 290                 fb_deferred_io_cleanup(info);
 291                 unregister_framebuffer(info);
 292                 vfree((void __force *)info->screen_base);
 293                 if (par->board->remove)
 294                         par->board->remove(par);
 295                 module_put(par->board->owner);
 296                 framebuffer_release(info);
 297         }
 298         return 0;
 299 }
 300
 301 static struct platform_driver hecubafb_driver = {
 302         .probe  = hecubafb_probe,
 303         .remove = hecubafb_remove,
 304         .driver = {
 305                 .owner  = THIS_MODULE,
 306                 .name   = "hecubafb",
 307         },
 308 };
 309
 310 static int __init hecubafb_init(void)
 311 {
 312         return platform_driver_register(&hecubafb_driver);
 313 }
 314
 315 static void __exit hecubafb_exit(void)
 316 {
 317         platform_driver_unregister(&hecubafb_driver);
 318 }
 319
 320 module_init(hecubafb_init);
 321 module_exit(hecubafb_exit);
 322
 323 MODULE_DESCRIPTION("fbdev driver for Hecuba/Apollo controller");
 324 MODULE_AUTHOR("Jaya Kumar");
 325 MODULE_LICENSE("GPL");