209 lines · c
1/*2 * linux/drivers/video/n411.c -- Platform device for N411 EPD kit3 *4 * Copyright (C) 2008, Jaya Kumar5 *6 * This file is subject to the terms and conditions of the GNU General Public7 * License. See the file COPYING in the main directory of this archive for8 * more details.9 *10 * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.11 *12 * This driver is written to be used with the Hecuba display controller13 * board, and tested with the EInk 800x600 display in 1 bit mode.14 * The interface between Hecuba and the host is TTL based GPIO. The15 * GPIO requirements are 8 writable data lines and 6 lines for control.16 * Only 4 of the controls are actually used here but 6 for future use.17 * The driver requires the IO addresses for data and control GPIO at18 * load time. It is also possible to use this display with a standard19 * PC parallel port.20 *21 * General notes:22 * - User must set dio_addr=0xIOADDR cio_addr=0xIOADDR c2io_addr=0xIOADDR23 *24 */25 26#include <linux/module.h>27#include <linux/kernel.h>28#include <linux/errno.h>29#include <linux/string.h>30#include <linux/delay.h>31#include <linux/interrupt.h>32#include <linux/fb.h>33#include <linux/init.h>34#include <linux/platform_device.h>35#include <linux/list.h>36#include <linux/uaccess.h>37#include <linux/irq.h>38 39#include <video/hecubafb.h>40 41static unsigned long dio_addr;42static unsigned long cio_addr;43static unsigned long c2io_addr;44static unsigned long splashval;45static unsigned int nosplash;46static unsigned char ctl;47 48static void n411_set_ctl(struct hecubafb_par *par, unsigned char bit, unsigned49 char state)50{51 switch (bit) {52 case HCB_CD_BIT:53 if (state)54 ctl &= ~(HCB_CD_BIT);55 else56 ctl |= HCB_CD_BIT;57 break;58 case HCB_DS_BIT:59 if (state)60 ctl &= ~(HCB_DS_BIT);61 else62 ctl |= HCB_DS_BIT;63 break;64 }65 outb(ctl, cio_addr);66}67 68static unsigned char n411_get_ctl(struct hecubafb_par *par)69{70 return inb(c2io_addr);71}72 73static void n411_set_data(struct hecubafb_par *par, unsigned char value)74{75 outb(value, dio_addr);76}77 78static void n411_wait_for_ack(struct hecubafb_par *par, int clear)79{80 int timeout;81 unsigned char tmp;82 83 timeout = 500;84 do {85 tmp = n411_get_ctl(par);86 if ((tmp & HCB_ACK_BIT) && (!clear))87 return;88 else if (!(tmp & HCB_ACK_BIT) && (clear))89 return;90 udelay(1);91 } while (timeout--);92 printk(KERN_ERR "timed out waiting for ack\n");93}94 95static int n411_init_control(struct hecubafb_par *par)96{97 unsigned char tmp;98 /* for init, we want the following setup to be set:99 WUP = lo100 ACK = hi101 DS = hi102 RW = hi103 CD = lo104 */105 106 /* write WUP to lo, DS to hi, RW to hi, CD to lo */107 ctl = HCB_WUP_BIT | HCB_RW_BIT | HCB_CD_BIT ;108 n411_set_ctl(par, HCB_DS_BIT, 1);109 110 /* check ACK is not lo */111 tmp = n411_get_ctl(par);112 if (tmp & HCB_ACK_BIT) {113 printk(KERN_ERR "Fail because ACK is already low\n");114 return -ENXIO;115 }116 117 return 0;118}119 120 121static int n411_init_board(struct hecubafb_par *par)122{123 int retval;124 125 retval = n411_init_control(par);126 if (retval)127 return retval;128 129 par->send_command(par, APOLLO_INIT_DISPLAY);130 par->send_data(par, 0x81);131 132 /* have to wait while display resets */133 udelay(1000);134 135 /* if we were told to splash the screen, we just clear it */136 if (!nosplash) {137 par->send_command(par, APOLLO_ERASE_DISPLAY);138 par->send_data(par, splashval);139 }140 141 return 0;142}143 144static struct hecuba_board n411_board = {145 .owner = THIS_MODULE,146 .init = n411_init_board,147 .set_ctl = n411_set_ctl,148 .set_data = n411_set_data,149 .wait_for_ack = n411_wait_for_ack,150};151 152static struct platform_device *n411_device;153static int __init n411_init(void)154{155 int ret;156 if (!dio_addr || !cio_addr || !c2io_addr) {157 printk(KERN_WARNING "no IO addresses supplied\n");158 return -EINVAL;159 }160 161 /* request our platform independent driver */162 request_module("hecubafb");163 164 n411_device = platform_device_alloc("hecubafb", -1);165 if (!n411_device)166 return -ENOMEM;167 168 ret = platform_device_add_data(n411_device, &n411_board,169 sizeof(n411_board));170 if (ret)171 goto put_plat_device;172 173 /* this _add binds hecubafb to n411. hecubafb refcounts n411 */174 ret = platform_device_add(n411_device);175 176 if (ret)177 goto put_plat_device;178 179 return 0;180 181put_plat_device:182 platform_device_put(n411_device);183 return ret;184}185 186static void __exit n411_exit(void)187{188 platform_device_unregister(n411_device);189}190 191module_init(n411_init);192module_exit(n411_exit);193 194module_param(nosplash, uint, 0);195MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");196module_param_hw(dio_addr, ulong, ioport, 0);197MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");198module_param_hw(cio_addr, ulong, ioport, 0);199MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");200module_param_hw(c2io_addr, ulong, ioport, 0);201MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");202module_param(splashval, ulong, 0);203MODULE_PARM_DESC(splashval, "Splash pattern: 0x00 is black, 0x01 is white");204 205MODULE_DESCRIPTION("board driver for n411 hecuba/apollo epd kit");206MODULE_AUTHOR("Jaya Kumar");207MODULE_LICENSE("GPL");208 209