summaryrefslogtreecommitdiff
path: root/drivers/video/n411.c
blob: 935830fea7b62f3eb47564b38917e67545c1febb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
/*
 * 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);
		else
			ctl |= HCB_CD_BIT;
		break;
	case HCB_DS_BIT:
		if (state)
			ctl &= ~(HCB_DS_BIT);
		else
			ctl |= HCB_DS_BIT;
		break;
	}
	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))
			return;
		else if (!(tmp & HCB_ACK_BIT) && (clear))
			return;
		udelay(1);
	} 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 */
	ctl = HCB_WUP_BIT | HCB_RW_BIT | HCB_CD_BIT ;
	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 */
	udelay(1000);

	/* 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 */
	request_module("hecubafb");

	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)
		platform_device_put(n411_device);

	return ret;

}

static void __exit n411_exit(void)
{
	platform_device_unregister(n411_device);
}

module_init(n411_init);
module_exit(n411_exit);

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");
MODULE_LICENSE("GPL");