hecubafb.c
/*
* linux/drivers/video/hecubafb.c -- FB driver for Hecuba/Apollo controller
*
* Copyright (C) 2006, Jaya Kumar
* This work was sponsored by CIS(M) Sdn Bhd
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive for
* more details.
*
* Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
* This work was possible because of apollo display code from E-Ink's website
* http://support.eink.com/community
* All information used to write this code is from public material made
* available by E-Ink on its support site. Some commands such as 0xA4
* were found by looping through cmd=0x00 thru 0xFF and supplying random
* values. There are other commands that the display is capable of,
* beyond the 5 used here but they are more complex.
*
* This driver is written to be used with the Hecuba display architecture.
* The actual display chip is called Apollo and the interface electronics
* it needs is called Hecuba.
*
* It is intended to be architecture independent. A board specific driver
* must be used to perform all the physical IO interactions. An example
* is provided as n411.c
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/list.h>
#include <linux/uaccess.h>
#include <video/hecubafb.h>
/* Display specific information */
#define DPY_W 600
#define DPY_H 800
static struct fb_fix_screeninfo hecubafb_fix __devinitdata = {
.id = "hecubafb",
.type = FB_TYPE_PACKED_PIXELS,
.visual = FB_VISUAL_MONO01,
.xpanstep = 0,
.ypanstep = 0,
.ywrapstep = 0,
.line_length = DPY_W,
.accel = FB_ACCEL_NONE,
};
static struct fb_var_screeninfo hecubafb_var __devinitdata = {
.xres = DPY_W,
.yres = DPY_H,
.xres_virtual = DPY_W,
.yres_virtual = DPY_H,
.bits_per_pixel = 1,
.nonstd = 1,
};
/* main hecubafb functions */
static void apollo_send_data(struct hecubafb_par *par, unsigned char data)
{
/* set data */
par->board->set_data(par, data);
/* set DS low */
par->board->set_ctl(par, HCB_DS_BIT, 0);
/* wait for ack */
par->board->wait_for_ack(par, 0);
/* set DS hi */
par->board->set_ctl(par, HCB_DS_BIT, 1);
/* wait for ack to clear */
par->board->wait_for_ack(par, 1);
}
static void apollo_send_command(struct hecubafb_par *par, unsigned char data)
{
/* command so set CD to high */
par->board->set_ctl(par, HCB_CD_BIT, 1);
/* actually strobe with command */
apollo_send_data(par, data);
/* clear CD back to low */
par->board->set_ctl(par, HCB_CD_BIT, 0);
}
static void hecubafb_dpy_update(struct hecubafb_par *par)
{
int i;
unsigned char *buf = (unsigned char __force *)par->info->screen_base;
apollo_send_command(par, APOLLO_START_NEW_IMG);
for (i=0; i < (DPY_W*DPY_H/8); i++) {
apollo_send_data(par, *(buf++));
}
apollo_send_command(par, APOLLO_STOP_IMG_DATA);
apollo_send_command(par, APOLLO_DISPLAY_IMG);
}
/* this is called back from the deferred io workqueue */
static void hecubafb_dpy_deferred_io(struct fb_info *info,
struct list_head *pagelist)
{
hecubafb_dpy_update(info->par);
}
static void hecubafb_fillrect(struct fb_info *info,
const struct fb_fillrect *rect)
{
struct hecubafb_par *par = info->par;
sys_fillrect(info, rect);
hecubafb_dpy_update(par);
}
static void hecubafb_copyarea(struct fb_info *info,
const struct fb_copyarea *area)
{
struct hecubafb_par *par = info->par;
sys_copyarea(info, area);
hecubafb_dpy_update(par);
}
static void hecubafb_imageblit(struct fb_info *info,
const struct fb_image *image)
{
struct hecubafb_par *par = info->par;
sys_imageblit(info, image);
hecubafb_dpy_update(par);
}
/*
* this is the slow path from userspace. they can seek and write to
* the fb. it's inefficient to do anything less than a full screen draw
*/
static ssize_t hecubafb_write(struct fb_info *info, const char __user *buf,
size_t count, loff_t *ppos)
{
struct hecubafb_par *par = info->par;
unsigned long p = *ppos;
void *dst;
int err = 0;
unsigned long total_size;
if (info->state != FBINFO_STATE_RUNNING)
return -EPERM;
total_size = info->fix.smem_len;
if (p > total_size)
return -EFBIG;
if (count > total_size) {
err = -EFBIG;
count = total_size;
}
if (count + p > total_size) {
if (!err)
err = -ENOSPC;
count = total_size - p;
}
dst = (void __force *) (info->screen_base + p);
if (copy_from_user(dst, buf, count))
err = -EFAULT;
if (!err)
*ppos += count;
hecubafb_dpy_update(par);
return (err) ? err : count;
}
static struct fb_ops hecubafb_ops = {
.owner = THIS_MODULE,
.fb_read = fb_sys_read,
.fb_write = hecubafb_write,
.fb_fillrect = hecubafb_fillrect,
.fb_copyarea = hecubafb_copyarea,
.fb_imageblit = hecubafb_imageblit,
};
static struct fb_deferred_io hecubafb_defio = {
.delay = HZ,
.deferred_io = hecubafb_dpy_deferred_io,
};
static int __devinit hecubafb_probe(struct platform_device *dev)
{
struct fb_info *info;
struct hecuba_board *board;
int retval = -ENOMEM;
int videomemorysize;
unsigned char *videomemory;
struct hecubafb_par *par;
/* pick up board specific routines */
board = dev->dev.platform_data;
if (!board)
return -EINVAL;
/* try to count device specific driver, if can't, platform recalls */
if (!try_module_get(board->owner))
return -ENODEV;
videomemorysize = (DPY_W*DPY_H)/8;
videomemory = vzalloc(videomemorysize);
if (!videomemory)
goto err_videomem_alloc;
info = framebuffer_alloc(sizeof(struct hecubafb_par), &dev->dev);
if (!info)
goto err_fballoc;
info->screen_base = (char __force __iomem *)videomemory;
info->fbops = &hecubafb_ops;
info->var = hecubafb_var;
info->fix = hecubafb_fix;
info->fix.smem_len = videomemorysize;
par = info->par;
par->info = info;
par->board = board;
par->send_command = apollo_send_command;
par->send_data = apollo_send_data;
info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
info->fbdefio = &hecubafb_defio;
fb_deferred_io_init(info);
retval = register_framebuffer(info);
if (retval < 0)
goto err_fbreg;
platform_set_drvdata(dev, info);
printk(KERN_INFO
"fb%d: Hecuba frame buffer device, using %dK of video memory\n",
info->node, videomemorysize >> 10);
/* this inits the dpy */
retval = par->board->init(par);
if (retval < 0)
goto err_fbreg;
return 0;
err_fbreg:
framebuffer_release(info);
err_fballoc:
vfree(videomemory);
err_videomem_alloc:
module_put(board->owner);
return retval;
}
static int __devexit hecubafb_remove(struct platform_device *dev)
{
struct fb_info *info = platform_get_drvdata(dev);
if (info) {
struct hecubafb_par *par = info->par;
fb_deferred_io_cleanup(info);
unregister_framebuffer(info);
vfree((void __force *)info->screen_base);
if (par->board->remove)
par->board->remove(par);
module_put(par->board->owner);
framebuffer_release(info);
}
return 0;
}
static struct platform_driver hecubafb_driver = {
.probe = hecubafb_probe,
.remove = __devexit_p(hecubafb_remove),
.driver = {
.owner = THIS_MODULE,
.name = "hecubafb",
},
};
static int __init hecubafb_init(void)
{
return platform_driver_register(&hecubafb_driver);
}
static void __exit hecubafb_exit(void)
{
platform_driver_unregister(&hecubafb_driver);
}
module_init(hecubafb_init);
module_exit(hecubafb_exit);
MODULE_DESCRIPTION("fbdev driver for Hecuba/Apollo controller");
MODULE_AUTHOR("Jaya Kumar");
MODULE_LICENSE("GPL");