drivers/video/fbdev/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/vmalloc.h>
  36 #include <linux/delay.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/fb.h>
  39 #include <linux/init.h>
  40 #include <linux/platform_device.h>
  41 #include <linux/list.h>
  42 #include <linux/uaccess.h>
  43
  44 #include <video/hecubafb.h>
  45
  46 /* Display specific information */
  47 #define DPY_W 600
  48 #define DPY_H 800
  49
  50 static const struct fb_fix_screeninfo hecubafb_fix = {
  51         .id =           "hecubafb",
  52         .type =         FB_TYPE_PACKED_PIXELS,
  53         .visual =       FB_VISUAL_MONO01,
  54         .xpanstep =     0,
  55         .ypanstep =     0,
  56         .ywrapstep =    0,
  57         .line_length =  DPY_W,
  58         .accel =        FB_ACCEL_NONE,
  59 };
  60
  61 static const struct fb_var_screeninfo hecubafb_var = {
  62         .xres           = DPY_W,
  63         .yres           = DPY_H,
  64         .xres_virtual   = DPY_W,
  65         .yres_virtual   = DPY_H,
  66         .bits_per_pixel = 1,
  67         .nonstd         = 1,
  68 };
  69
  70 /* main hecubafb functions */
  71
  72 static void apollo_send_data(struct hecubafb_par *par, unsigned char data)
  73 {
  74         /* set data */
  75         par->board->set_data(par, data);
  76
  77         /* set DS low */
  78         par->board->set_ctl(par, HCB_DS_BIT, 0);
  79
  80         /* wait for ack */
  81         par->board->wait_for_ack(par, 0);
  82
  83         /* set DS hi */
  84         par->board->set_ctl(par, HCB_DS_BIT, 1);
  85
  86         /* wait for ack to clear */
  87         par->board->wait_for_ack(par, 1);
  88 }
  89
  90 static void apollo_send_command(struct hecubafb_par *par, unsigned char data)
  91 {
  92         /* command so set CD to high */
  93         par->board->set_ctl(par, HCB_CD_BIT, 1);
  94
  95         /* actually strobe with command */
  96         apollo_send_data(par, data);
  97
  98         /* clear CD back to low */
  99         par->board->set_ctl(par, HCB_CD_BIT, 0);
 100 }
 101
 102 static void hecubafb_dpy_update(struct hecubafb_par *par)
 103 {
 104         int i;
 105         unsigned char *buf = par->info->screen_buffer;
 106
 107         apollo_send_command(par, APOLLO_START_NEW_IMG);
 108
 109         for (i=0; i < (DPY_W*DPY_H/8); i++) {
 110                 apollo_send_data(par, *(buf++));
 111         }
 112
 113         apollo_send_command(par, APOLLO_STOP_IMG_DATA);
 114         apollo_send_command(par, APOLLO_DISPLAY_IMG);
 115 }
 116
 117 /* this is called back from the deferred io workqueue */
 118 static void hecubafb_dpy_deferred_io(struct fb_info *info, struct list_head *pagereflist)
 119 {
 120         hecubafb_dpy_update(info->par);
 121 }
 122
 123 static void hecubafb_defio_damage_range(struct fb_info *info, off_t off, size_t len)
 124 {
 125         struct hecubafb_par *par = info->par;
 126
 127         hecubafb_dpy_update(par);
 128 }
 129
 130 static void hecubafb_defio_damage_area(struct fb_info *info, u32 x, u32 y,
 131                                        u32 width, u32 height)
 132 {
 133         struct hecubafb_par *par = info->par;
 134
 135         hecubafb_dpy_update(par);
 136 }
 137
 138 FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(hecubafb,
 139                                    hecubafb_defio_damage_range,
 140                                    hecubafb_defio_damage_area)
 141
 142 static const struct fb_ops hecubafb_ops = {
 143         .owner  = THIS_MODULE,
 144         FB_DEFAULT_DEFERRED_OPS(hecubafb),
 145 };
 146
 147 static struct fb_deferred_io hecubafb_defio = {
 148         .delay          = HZ,
 149         .deferred_io    = hecubafb_dpy_deferred_io,
 150 };
 151
 152 static int hecubafb_probe(struct platform_device *dev)
 153 {
 154         struct fb_info *info;
 155         struct hecuba_board *board;
 156         int retval = -ENOMEM;
 157         int videomemorysize;
 158         unsigned char *videomemory;
 159         struct hecubafb_par *par;
 160
 161         /* pick up board specific routines */
 162         board = dev->dev.platform_data;
 163         if (!board)
 164                 return -EINVAL;
 165
 166         /* try to count device specific driver, if can't, platform recalls */
 167         if (!try_module_get(board->owner))
 168                 return -ENODEV;
 169
 170         videomemorysize = (DPY_W*DPY_H)/8;
 171
 172         videomemory = vzalloc(videomemorysize);
 173         if (!videomemory)
 174                 goto err_videomem_alloc;
 175
 176         info = framebuffer_alloc(sizeof(struct hecubafb_par), &dev->dev);
 177         if (!info)
 178                 goto err_fballoc;
 179
 180         info->screen_buffer = videomemory;
 181         info->fbops = &hecubafb_ops;
 182
 183         info->var = hecubafb_var;
 184         info->fix = hecubafb_fix;
 185         info->fix.smem_len = videomemorysize;
 186         par = info->par;
 187         par->info = info;
 188         par->board = board;
 189         par->send_command = apollo_send_command;
 190         par->send_data = apollo_send_data;
 191
 192         info->flags = FBINFO_VIRTFB;
 193
 194         info->fbdefio = &hecubafb_defio;
 195         fb_deferred_io_init(info);
 196
 197         retval = register_framebuffer(info);
 198         if (retval < 0)
 199                 goto err_fbreg;
 200         platform_set_drvdata(dev, info);
 201
 202         fb_info(info, "Hecuba frame buffer device, using %dK of video memory\n",
 203                 videomemorysize >> 10);
 204
 205         /* this inits the dpy */
 206         retval = par->board->init(par);
 207         if (retval < 0)
 208                 goto err_fbreg;
 209
 210         return 0;
 211 err_fbreg:
 212         framebuffer_release(info);
 213 err_fballoc:
 214         vfree(videomemory);
 215 err_videomem_alloc:
 216         module_put(board->owner);
 217         return retval;
 218 }
 219
 220 static void hecubafb_remove(struct platform_device *dev)
 221 {
 222         struct fb_info *info = platform_get_drvdata(dev);
 223
 224         if (info) {
 225                 struct hecubafb_par *par = info->par;
 226                 fb_deferred_io_cleanup(info);
 227                 unregister_framebuffer(info);
 228                 vfree(info->screen_buffer);
 229                 if (par->board->remove)
 230                         par->board->remove(par);
 231                 module_put(par->board->owner);
 232                 framebuffer_release(info);
 233         }
 234 }
 235
 236 static struct platform_driver hecubafb_driver = {
 237         .probe  = hecubafb_probe,
 238         .remove = hecubafb_remove,
 239         .driver = {
 240                 .name   = "hecubafb",
 241         },
 242 };
 243 module_platform_driver(hecubafb_driver);
 244
 245 MODULE_DESCRIPTION("fbdev driver for Hecuba/Apollo controller");
 246 MODULE_AUTHOR("Jaya Kumar");
 247 MODULE_LICENSE("GPL");