1f7018c21STomi Valkeinen /*
2f7018c21STomi Valkeinen * linux/drivers/video/n411.c -- Platform device for N411 EPD kit
3f7018c21STomi Valkeinen *
4f7018c21STomi Valkeinen * Copyright (C) 2008, Jaya Kumar
5f7018c21STomi Valkeinen *
6f7018c21STomi Valkeinen * This file is subject to the terms and conditions of the GNU General Public
7f7018c21STomi Valkeinen * License. See the file COPYING in the main directory of this archive for
8f7018c21STomi Valkeinen * more details.
9f7018c21STomi Valkeinen *
10f7018c21STomi Valkeinen * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
11f7018c21STomi Valkeinen *
12f7018c21STomi Valkeinen * This driver is written to be used with the Hecuba display controller
13f7018c21STomi Valkeinen * board, and tested with the EInk 800x600 display in 1 bit mode.
14f7018c21STomi Valkeinen * The interface between Hecuba and the host is TTL based GPIO. The
15f7018c21STomi Valkeinen * GPIO requirements are 8 writable data lines and 6 lines for control.
16f7018c21STomi Valkeinen * Only 4 of the controls are actually used here but 6 for future use.
17f7018c21STomi Valkeinen * The driver requires the IO addresses for data and control GPIO at
18f7018c21STomi Valkeinen * load time. It is also possible to use this display with a standard
19f7018c21STomi Valkeinen * PC parallel port.
20f7018c21STomi Valkeinen *
21f7018c21STomi Valkeinen * General notes:
22f7018c21STomi Valkeinen * - User must set dio_addr=0xIOADDR cio_addr=0xIOADDR c2io_addr=0xIOADDR
23f7018c21STomi Valkeinen *
24f7018c21STomi Valkeinen */
25f7018c21STomi Valkeinen
26f7018c21STomi Valkeinen #include <linux/module.h>
27f7018c21STomi Valkeinen #include <linux/kernel.h>
28f7018c21STomi Valkeinen #include <linux/errno.h>
29f7018c21STomi Valkeinen #include <linux/string.h>
30f7018c21STomi Valkeinen #include <linux/delay.h>
31f7018c21STomi Valkeinen #include <linux/interrupt.h>
32f7018c21STomi Valkeinen #include <linux/fb.h>
33f7018c21STomi Valkeinen #include <linux/init.h>
34f7018c21STomi Valkeinen #include <linux/platform_device.h>
35f7018c21STomi Valkeinen #include <linux/list.h>
36f7018c21STomi Valkeinen #include <linux/uaccess.h>
37f7018c21STomi Valkeinen #include <linux/irq.h>
38f7018c21STomi Valkeinen
39f7018c21STomi Valkeinen #include <video/hecubafb.h>
40f7018c21STomi Valkeinen
41f7018c21STomi Valkeinen static unsigned long dio_addr;
42f7018c21STomi Valkeinen static unsigned long cio_addr;
43f7018c21STomi Valkeinen static unsigned long c2io_addr;
44f7018c21STomi Valkeinen static unsigned long splashval;
45f7018c21STomi Valkeinen static unsigned int nosplash;
46f7018c21STomi Valkeinen static unsigned char ctl;
47f7018c21STomi Valkeinen
n411_set_ctl(struct hecubafb_par * par,unsigned char bit,unsigned char state)48f7018c21STomi Valkeinen static void n411_set_ctl(struct hecubafb_par *par, unsigned char bit, unsigned
49f7018c21STomi Valkeinen char state)
50f7018c21STomi Valkeinen {
51f7018c21STomi Valkeinen switch (bit) {
52f7018c21STomi Valkeinen case HCB_CD_BIT:
53f7018c21STomi Valkeinen if (state)
54f7018c21STomi Valkeinen ctl &= ~(HCB_CD_BIT);
55f7018c21STomi Valkeinen else
56f7018c21STomi Valkeinen ctl |= HCB_CD_BIT;
57f7018c21STomi Valkeinen break;
58f7018c21STomi Valkeinen case HCB_DS_BIT:
59f7018c21STomi Valkeinen if (state)
60f7018c21STomi Valkeinen ctl &= ~(HCB_DS_BIT);
61f7018c21STomi Valkeinen else
62f7018c21STomi Valkeinen ctl |= HCB_DS_BIT;
63f7018c21STomi Valkeinen break;
64f7018c21STomi Valkeinen }
65f7018c21STomi Valkeinen outb(ctl, cio_addr);
66f7018c21STomi Valkeinen }
67f7018c21STomi Valkeinen
n411_get_ctl(struct hecubafb_par * par)68f7018c21STomi Valkeinen static unsigned char n411_get_ctl(struct hecubafb_par *par)
69f7018c21STomi Valkeinen {
70f7018c21STomi Valkeinen return inb(c2io_addr);
71f7018c21STomi Valkeinen }
72f7018c21STomi Valkeinen
n411_set_data(struct hecubafb_par * par,unsigned char value)73f7018c21STomi Valkeinen static void n411_set_data(struct hecubafb_par *par, unsigned char value)
74f7018c21STomi Valkeinen {
75f7018c21STomi Valkeinen outb(value, dio_addr);
76f7018c21STomi Valkeinen }
77f7018c21STomi Valkeinen
n411_wait_for_ack(struct hecubafb_par * par,int clear)78f7018c21STomi Valkeinen static void n411_wait_for_ack(struct hecubafb_par *par, int clear)
79f7018c21STomi Valkeinen {
80f7018c21STomi Valkeinen int timeout;
81f7018c21STomi Valkeinen unsigned char tmp;
82f7018c21STomi Valkeinen
83f7018c21STomi Valkeinen timeout = 500;
84f7018c21STomi Valkeinen do {
85f7018c21STomi Valkeinen tmp = n411_get_ctl(par);
86f7018c21STomi Valkeinen if ((tmp & HCB_ACK_BIT) && (!clear))
87f7018c21STomi Valkeinen return;
88f7018c21STomi Valkeinen else if (!(tmp & HCB_ACK_BIT) && (clear))
89f7018c21STomi Valkeinen return;
90f7018c21STomi Valkeinen udelay(1);
91f7018c21STomi Valkeinen } while (timeout--);
92f7018c21STomi Valkeinen printk(KERN_ERR "timed out waiting for ack\n");
93f7018c21STomi Valkeinen }
94f7018c21STomi Valkeinen
n411_init_control(struct hecubafb_par * par)95f7018c21STomi Valkeinen static int n411_init_control(struct hecubafb_par *par)
96f7018c21STomi Valkeinen {
97f7018c21STomi Valkeinen unsigned char tmp;
98f7018c21STomi Valkeinen /* for init, we want the following setup to be set:
99f7018c21STomi Valkeinen WUP = lo
100f7018c21STomi Valkeinen ACK = hi
101f7018c21STomi Valkeinen DS = hi
102f7018c21STomi Valkeinen RW = hi
103f7018c21STomi Valkeinen CD = lo
104f7018c21STomi Valkeinen */
105f7018c21STomi Valkeinen
106f7018c21STomi Valkeinen /* write WUP to lo, DS to hi, RW to hi, CD to lo */
107f7018c21STomi Valkeinen ctl = HCB_WUP_BIT | HCB_RW_BIT | HCB_CD_BIT ;
108f7018c21STomi Valkeinen n411_set_ctl(par, HCB_DS_BIT, 1);
109f7018c21STomi Valkeinen
110f7018c21STomi Valkeinen /* check ACK is not lo */
111f7018c21STomi Valkeinen tmp = n411_get_ctl(par);
112f7018c21STomi Valkeinen if (tmp & HCB_ACK_BIT) {
113f7018c21STomi Valkeinen printk(KERN_ERR "Fail because ACK is already low\n");
114f7018c21STomi Valkeinen return -ENXIO;
115f7018c21STomi Valkeinen }
116f7018c21STomi Valkeinen
117f7018c21STomi Valkeinen return 0;
118f7018c21STomi Valkeinen }
119f7018c21STomi Valkeinen
120f7018c21STomi Valkeinen
n411_init_board(struct hecubafb_par * par)121f7018c21STomi Valkeinen static int n411_init_board(struct hecubafb_par *par)
122f7018c21STomi Valkeinen {
123f7018c21STomi Valkeinen int retval;
124f7018c21STomi Valkeinen
125f7018c21STomi Valkeinen retval = n411_init_control(par);
126f7018c21STomi Valkeinen if (retval)
127f7018c21STomi Valkeinen return retval;
128f7018c21STomi Valkeinen
129f7018c21STomi Valkeinen par->send_command(par, APOLLO_INIT_DISPLAY);
130f7018c21STomi Valkeinen par->send_data(par, 0x81);
131f7018c21STomi Valkeinen
132f7018c21STomi Valkeinen /* have to wait while display resets */
133f7018c21STomi Valkeinen udelay(1000);
134f7018c21STomi Valkeinen
135f7018c21STomi Valkeinen /* if we were told to splash the screen, we just clear it */
136f7018c21STomi Valkeinen if (!nosplash) {
137f7018c21STomi Valkeinen par->send_command(par, APOLLO_ERASE_DISPLAY);
138f7018c21STomi Valkeinen par->send_data(par, splashval);
139f7018c21STomi Valkeinen }
140f7018c21STomi Valkeinen
141f7018c21STomi Valkeinen return 0;
142f7018c21STomi Valkeinen }
143f7018c21STomi Valkeinen
144f7018c21STomi Valkeinen static struct hecuba_board n411_board = {
145f7018c21STomi Valkeinen .owner = THIS_MODULE,
146f7018c21STomi Valkeinen .init = n411_init_board,
147f7018c21STomi Valkeinen .set_ctl = n411_set_ctl,
148f7018c21STomi Valkeinen .set_data = n411_set_data,
149f7018c21STomi Valkeinen .wait_for_ack = n411_wait_for_ack,
150f7018c21STomi Valkeinen };
151f7018c21STomi Valkeinen
152f7018c21STomi Valkeinen static struct platform_device *n411_device;
n411_init(void)153f7018c21STomi Valkeinen static int __init n411_init(void)
154f7018c21STomi Valkeinen {
155f7018c21STomi Valkeinen int ret;
156f7018c21STomi Valkeinen if (!dio_addr || !cio_addr || !c2io_addr) {
157f7018c21STomi Valkeinen printk(KERN_WARNING "no IO addresses supplied\n");
158f7018c21STomi Valkeinen return -EINVAL;
159f7018c21STomi Valkeinen }
160f7018c21STomi Valkeinen
161f7018c21STomi Valkeinen /* request our platform independent driver */
162f7018c21STomi Valkeinen request_module("hecubafb");
163f7018c21STomi Valkeinen
164f7018c21STomi Valkeinen n411_device = platform_device_alloc("hecubafb", -1);
165f7018c21STomi Valkeinen if (!n411_device)
166f7018c21STomi Valkeinen return -ENOMEM;
167f7018c21STomi Valkeinen
1687fdfc702SSudip Mukherjee ret = platform_device_add_data(n411_device, &n411_board,
1697fdfc702SSudip Mukherjee sizeof(n411_board));
1707fdfc702SSudip Mukherjee if (ret)
1717fdfc702SSudip Mukherjee goto put_plat_device;
172f7018c21STomi Valkeinen
173f7018c21STomi Valkeinen /* this _add binds hecubafb to n411. hecubafb refcounts n411 */
174f7018c21STomi Valkeinen ret = platform_device_add(n411_device);
175f7018c21STomi Valkeinen
176f7018c21STomi Valkeinen if (ret)
1777fdfc702SSudip Mukherjee goto put_plat_device;
1787fdfc702SSudip Mukherjee
1797fdfc702SSudip Mukherjee return 0;
1807fdfc702SSudip Mukherjee
1817fdfc702SSudip Mukherjee put_plat_device:
182f7018c21STomi Valkeinen platform_device_put(n411_device);
183f7018c21STomi Valkeinen return ret;
184f7018c21STomi Valkeinen }
185f7018c21STomi Valkeinen
n411_exit(void)186f7018c21STomi Valkeinen static void __exit n411_exit(void)
187f7018c21STomi Valkeinen {
188f7018c21STomi Valkeinen platform_device_unregister(n411_device);
189f7018c21STomi Valkeinen }
190f7018c21STomi Valkeinen
191f7018c21STomi Valkeinen module_init(n411_init);
192f7018c21STomi Valkeinen module_exit(n411_exit);
193f7018c21STomi Valkeinen
194f7018c21STomi Valkeinen module_param(nosplash, uint, 0);
195f7018c21STomi Valkeinen MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
196*c729203dSDavid Howells module_param_hw(dio_addr, ulong, ioport, 0);
197f7018c21STomi Valkeinen MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
198*c729203dSDavid Howells module_param_hw(cio_addr, ulong, ioport, 0);
199f7018c21STomi Valkeinen MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
200*c729203dSDavid Howells module_param_hw(c2io_addr, ulong, ioport, 0);
201f7018c21STomi Valkeinen MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
202f7018c21STomi Valkeinen module_param(splashval, ulong, 0);
203f7018c21STomi Valkeinen MODULE_PARM_DESC(splashval, "Splash pattern: 0x00 is black, 0x01 is white");
204f7018c21STomi Valkeinen
205f7018c21STomi Valkeinen MODULE_DESCRIPTION("board driver for n411 hecuba/apollo epd kit");
206f7018c21STomi Valkeinen MODULE_AUTHOR("Jaya Kumar");
207f7018c21STomi Valkeinen MODULE_LICENSE("GPL");
208f7018c21STomi Valkeinen
209