1 /*
2 * linux/drivers/video/n411.c -- Platform device for N411 EPD kit
3 *
4 * Copyright (C) 2008, Jaya Kumar
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file COPYING in the main directory of this archive for
8 * 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 controller
13 * board, and tested with the EInk 800x600 display in 1 bit mode.
14 * The interface between Hecuba and the host is TTL based GPIO. The
15 * 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 at
18 * load time. It is also possible to use this display with a standard
19 * PC parallel port.
20 *
21 * General notes:
22 * - User must set dio_addr=0xIOADDR cio_addr=0xIOADDR c2io_addr=0xIOADDR
23 *
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
41 static unsigned long dio_addr;
42 static unsigned long cio_addr;
43 static unsigned long c2io_addr;
44 static unsigned long splashval;
45 static unsigned int nosplash;
46 static unsigned char ctl;
47
n411_set_ctl(struct hecubafb_par * par,unsigned char bit,unsigned char state)48 static void n411_set_ctl(struct hecubafb_par *par, unsigned char bit, unsigned
49 char state)
50 {
51 switch (bit) {
52 case HCB_CD_BIT:
53 if (state)
54 ctl &= ~(HCB_CD_BIT);
55 else
56 ctl |= HCB_CD_BIT;
57 break;
58 case HCB_DS_BIT:
59 if (state)
60 ctl &= ~(HCB_DS_BIT);
61 else
62 ctl |= HCB_DS_BIT;
63 break;
64 }
65 outb(ctl, cio_addr);
66 }
67
n411_get_ctl(struct hecubafb_par * par)68 static unsigned char n411_get_ctl(struct hecubafb_par *par)
69 {
70 return inb(c2io_addr);
71 }
72
n411_set_data(struct hecubafb_par * par,unsigned char value)73 static void n411_set_data(struct hecubafb_par *par, unsigned char value)
74 {
75 outb(value, dio_addr);
76 }
77
n411_wait_for_ack(struct hecubafb_par * par,int clear)78 static 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
n411_init_control(struct hecubafb_par * par)95 static 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 = lo
100 ACK = hi
101 DS = hi
102 RW = hi
103 CD = lo
104 */
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
n411_init_board(struct hecubafb_par * par)121 static 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
144 static 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
152 static struct platform_device *n411_device;
n411_init(void)153 static 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
181 put_plat_device:
182 platform_device_put(n411_device);
183 return ret;
184 }
185
n411_exit(void)186 static void __exit n411_exit(void)
187 {
188 platform_device_unregister(n411_device);
189 }
190
191 module_init(n411_init);
192 module_exit(n411_exit);
193
194 module_param(nosplash, uint, 0);
195 MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
196 module_param_hw(dio_addr, ulong, ioport, 0);
197 MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
198 module_param_hw(cio_addr, ulong, ioport, 0);
199 MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
200 module_param_hw(c2io_addr, ulong, ioport, 0);
201 MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
202 module_param(splashval, ulong, 0);
203 MODULE_PARM_DESC(splashval, "Splash pattern: 0x00 is black, 0x01 is white");
204
205 MODULE_DESCRIPTION("board driver for n411 hecuba/apollo epd kit");
206 MODULE_AUTHOR("Jaya Kumar");
207 MODULE_LICENSE("GPL");
208
209