blob: 935830fea7b62f3eb47564b38917e67545c1febb [file] [log] [blame]
* linux/drivers/video/n411.c -- Platform device for N411 EPD kit
* Copyright (C) 2008, Jaya Kumar
* 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 driver is written to be used with the Hecuba display controller
* board, and tested with the EInk 800x600 display in 1 bit mode.
* The interface between Hecuba and the host is TTL based GPIO. The
* GPIO requirements are 8 writable data lines and 6 lines for control.
* Only 4 of the controls are actually used here but 6 for future use.
* The driver requires the IO addresses for data and control GPIO at
* load time. It is also possible to use this display with a standard
* PC parallel port.
* General notes:
* - User must set dio_addr=0xIOADDR cio_addr=0xIOADDR c2io_addr=0xIOADDR
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.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 <linux/irq.h>
#include <video/hecubafb.h>
static unsigned long dio_addr;
static unsigned long cio_addr;
static unsigned long c2io_addr;
static unsigned long splashval;
static unsigned int nosplash;
static unsigned char ctl;
static void n411_set_ctl(struct hecubafb_par *par, unsigned char bit, unsigned
char state)
switch (bit) {
case HCB_CD_BIT:
if (state)
ctl &= ~(HCB_CD_BIT);
ctl |= HCB_CD_BIT;
case HCB_DS_BIT:
if (state)
ctl &= ~(HCB_DS_BIT);
ctl |= HCB_DS_BIT;
outb(ctl, cio_addr);
static unsigned char n411_get_ctl(struct hecubafb_par *par)
return inb(c2io_addr);
static void n411_set_data(struct hecubafb_par *par, unsigned char value)
outb(value, dio_addr);
static void n411_wait_for_ack(struct hecubafb_par *par, int clear)
int timeout;
unsigned char tmp;
timeout = 500;
do {
tmp = n411_get_ctl(par);
if ((tmp & HCB_ACK_BIT) && (!clear))
else if (!(tmp & HCB_ACK_BIT) && (clear))
} while (timeout--);
printk(KERN_ERR "timed out waiting for ack\n");
static int n411_init_control(struct hecubafb_par *par)
unsigned char tmp;
/* for init, we want the following setup to be set:
WUP = lo
ACK = hi
DS = hi
RW = hi
CD = lo
/* write WUP to lo, DS to hi, RW to hi, CD to lo */
n411_set_ctl(par, HCB_DS_BIT, 1);
/* check ACK is not lo */
tmp = n411_get_ctl(par);
if (tmp & HCB_ACK_BIT) {
printk(KERN_ERR "Fail because ACK is already low\n");
return -ENXIO;
return 0;
static int n411_init_board(struct hecubafb_par *par)
int retval;
retval = n411_init_control(par);
if (retval)
return retval;
par->send_command(par, APOLLO_INIT_DISPLAY);
par->send_data(par, 0x81);
/* have to wait while display resets */
/* if we were told to splash the screen, we just clear it */
if (!nosplash) {
par->send_command(par, APOLLO_ERASE_DISPLAY);
par->send_data(par, splashval);
return 0;
static struct hecuba_board n411_board = {
.owner = THIS_MODULE,
.init = n411_init_board,
.set_ctl = n411_set_ctl,
.set_data = n411_set_data,
.wait_for_ack = n411_wait_for_ack,
static struct platform_device *n411_device;
static int __init n411_init(void)
int ret;
if (!dio_addr || !cio_addr || !c2io_addr) {
printk(KERN_WARNING "no IO addresses supplied\n");
return -EINVAL;
/* request our platform independent driver */
n411_device = platform_device_alloc("hecubafb", -1);
if (!n411_device)
return -ENOMEM;
platform_device_add_data(n411_device, &n411_board, sizeof(n411_board));
/* this _add binds hecubafb to n411. hecubafb refcounts n411 */
ret = platform_device_add(n411_device);
if (ret)
return ret;
static void __exit n411_exit(void)
module_param(nosplash, uint, 0);
MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
module_param(dio_addr, ulong, 0);
MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
module_param(cio_addr, ulong, 0);
MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
module_param(c2io_addr, ulong, 0);
MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
module_param(splashval, ulong, 0);
MODULE_PARM_DESC(splashval, "Splash pattern: 0x00 is black, 0x01 is white");
MODULE_DESCRIPTION("board driver for n411 hecuba/apollo epd kit");
MODULE_AUTHOR("Jaya Kumar");