summaryrefslogtreecommitdiff
path: root/drivers/video/hecubafb.c
blob: dc12e2d5489e35450ef7a73827739c1b7c21ea4e (plain)
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
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
/*
 * linux/drivers/video/hecubafb.c -- FB driver for Hecuba controller
 *
 * Copyright (C) 2006, Jaya Kumar
 * This work was sponsored by CIS(M) Sdn Bhd
 *
 * 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 work was possible because of apollo display code from E-Ink's website
 * http://support.eink.com/community
 * All information used to write this code is from public material made
 * available by E-Ink on its support site. Some commands such as 0xA4
 * were found by looping through cmd=0x00 thru 0xFF and supplying random
 * values. There are other commands that the display is capable of,
 * beyond the 5 used here but they are more complex.
 *
 * 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 hecubafb_enable=1 to enable it
 * - 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/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.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 <asm/uaccess.h>

/* Apollo controller specific defines */
#define APOLLO_START_NEW_IMG	0xA0
#define APOLLO_STOP_IMG_DATA	0xA1
#define APOLLO_DISPLAY_IMG	0xA2
#define APOLLO_ERASE_DISPLAY	0xA3
#define APOLLO_INIT_DISPLAY	0xA4

/* Hecuba interface specific defines */
/* WUP is inverted, CD is inverted, DS is inverted */
#define HCB_NWUP_BIT	0x01
#define HCB_NDS_BIT 	0x02
#define HCB_RW_BIT 	0x04
#define HCB_NCD_BIT 	0x08
#define HCB_ACK_BIT 	0x80

/* Display specific information */
#define DPY_W 600
#define DPY_H 800

struct hecubafb_par {
	unsigned long dio_addr;
	unsigned long cio_addr;
	unsigned long c2io_addr;
	unsigned char ctl;
	struct fb_info *info;
	unsigned int irq;
};

static struct fb_fix_screeninfo hecubafb_fix __devinitdata = {
	.id =		"hecubafb",
	.type =		FB_TYPE_PACKED_PIXELS,
	.visual =	FB_VISUAL_MONO01,
	.xpanstep =	0,
	.ypanstep =	0,
	.ywrapstep =	0,
	.accel =	FB_ACCEL_NONE,
};

static struct fb_var_screeninfo hecubafb_var __devinitdata = {
	.xres		= DPY_W,
	.yres		= DPY_H,
	.xres_virtual	= DPY_W,
	.yres_virtual	= DPY_H,
	.bits_per_pixel	= 1,
	.nonstd		= 1,
};

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 int hecubafb_enable;
static unsigned int irq;

static DECLARE_WAIT_QUEUE_HEAD(hecubafb_waitq);

static void hcb_set_ctl(struct hecubafb_par *par)
{
	outb(par->ctl, par->cio_addr);
}

static unsigned char hcb_get_ctl(struct hecubafb_par *par)
{
	return inb(par->c2io_addr);
}

static void hcb_set_data(struct hecubafb_par *par, unsigned char value)
{
	outb(value, par->dio_addr);
}

static int __devinit apollo_init_control(struct hecubafb_par *par)
{
	unsigned char ctl;
	/* 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 */
	par->ctl = HCB_NWUP_BIT | HCB_RW_BIT | HCB_NCD_BIT ;
	par->ctl &= ~HCB_NDS_BIT;
	hcb_set_ctl(par);

	/* check ACK is not lo */
	ctl = hcb_get_ctl(par);
	if ((ctl & HCB_ACK_BIT)) {
		printk(KERN_ERR "Fail because ACK is already low\n");
		return -ENXIO;
	}

	return 0;
}

static void hcb_wait_for_ack(struct hecubafb_par *par)
{

	int timeout;
	unsigned char ctl;

	timeout=500;
	do {
		ctl = hcb_get_ctl(par);
		if ((ctl & HCB_ACK_BIT))
			return;
		udelay(1);
	} while (timeout--);
	printk(KERN_ERR "timed out waiting for ack\n");
}

static void hcb_wait_for_ack_clear(struct hecubafb_par *par)
{

	int timeout;
	unsigned char ctl;

	timeout=500;
	do {
		ctl = hcb_get_ctl(par);
		if (!(ctl & HCB_ACK_BIT))
			return;
		udelay(1);
	} while (timeout--);
	printk(KERN_ERR "timed out waiting for clear\n");
}

static void apollo_send_data(struct hecubafb_par *par, unsigned char data)
{
	/* set data */
	hcb_set_data(par, data);

	/* set DS low */
	par->ctl |= HCB_NDS_BIT;
	hcb_set_ctl(par);

	hcb_wait_for_ack(par);

	/* set DS hi */
	par->ctl &= ~(HCB_NDS_BIT);
	hcb_set_ctl(par);

	hcb_wait_for_ack_clear(par);
}

static void apollo_send_command(struct hecubafb_par *par, unsigned char data)
{
	/* command so set CD to high */
	par->ctl &= ~(HCB_NCD_BIT);
	hcb_set_ctl(par);

	/* actually strobe with command */
	apollo_send_data(par, data);

	/* clear CD back to low */
	par->ctl |= (HCB_NCD_BIT);
	hcb_set_ctl(par);
}

/* main hecubafb functions */

static void hecubafb_dpy_update(struct hecubafb_par *par)
{
	int i;
	unsigned char *buf = (unsigned char __force *)par->info->screen_base;

	apollo_send_command(par, 0xA0);

	for (i=0; i < (DPY_W*DPY_H/8); i++) {
		apollo_send_data(par, *(buf++));
	}

	apollo_send_command(par, 0xA1);
	apollo_send_command(par, 0xA2);
}

/* this is called back from the deferred io workqueue */
static void hecubafb_dpy_deferred_io(struct fb_info *info,
				struct list_head *pagelist)
{
	hecubafb_dpy_update(info->par);
}

static void hecubafb_fillrect(struct fb_info *info,
				   const struct fb_fillrect *rect)
{
	struct hecubafb_par *par = info->par;

	cfb_fillrect(info, rect);

	hecubafb_dpy_update(par);
}

static void hecubafb_copyarea(struct fb_info *info,
				   const struct fb_copyarea *area)
{
	struct hecubafb_par *par = info->par;

	cfb_copyarea(info, area);

	hecubafb_dpy_update(par);
}

static void hecubafb_imageblit(struct fb_info *info,
				const struct fb_image *image)
{
	struct hecubafb_par *par = info->par;

	cfb_imageblit(info, image);

	hecubafb_dpy_update(par);
}

/*
 * this is the slow path from userspace. they can seek and write to
 * the fb. it's inefficient to do anything less than a full screen draw
 */
static ssize_t hecubafb_write(struct file *file, const char __user *buf,
				size_t count, loff_t *ppos)
{
	struct inode *inode;
	int fbidx;
	struct fb_info *info;
	unsigned long p;
	int err=-EINVAL;
	struct hecubafb_par *par;
	unsigned int xres;
	unsigned int fbmemlength;

	p = *ppos;
	inode = file->f_dentry->d_inode;
	fbidx = iminor(inode);
	info = registered_fb[fbidx];

	if (!info || !info->screen_base)
		return -ENODEV;

	par = info->par;
	xres = info->var.xres;
	fbmemlength = (xres * info->var.yres)/8;

	if (p > fbmemlength)
		return -ENOSPC;

	err = 0;
	if ((count + p) > fbmemlength) {
		count = fbmemlength - p;
		err = -ENOSPC;
	}

	if (count) {
		char *base_addr;

		base_addr = (char __force *)info->screen_base;
		count -= copy_from_user(base_addr + p, buf, count);
		*ppos += count;
		err = -EFAULT;
	}

	hecubafb_dpy_update(par);

	if (count)
		return count;

	return err;
}

static struct fb_ops hecubafb_ops = {
	.owner		= THIS_MODULE,
	.fb_write	= hecubafb_write,
	.fb_fillrect	= hecubafb_fillrect,
	.fb_copyarea	= hecubafb_copyarea,
	.fb_imageblit	= hecubafb_imageblit,
};

static struct fb_deferred_io hecubafb_defio = {
	.delay		= HZ,
	.deferred_io	= hecubafb_dpy_deferred_io,
};

static int __devinit hecubafb_probe(struct platform_device *dev)
{
	struct fb_info *info;
	int retval = -ENOMEM;
	int videomemorysize;
	unsigned char *videomemory;
	struct hecubafb_par *par;

	videomemorysize = (DPY_W*DPY_H)/8;

	if (!(videomemory = vmalloc(videomemorysize)))
		return retval;

	memset(videomemory, 0, videomemorysize);

	info = framebuffer_alloc(sizeof(struct hecubafb_par), &dev->dev);
	if (!info)
		goto err;

	info->screen_base = (char __iomem *) videomemory;
	info->fbops = &hecubafb_ops;

	info->var = hecubafb_var;
	info->fix = hecubafb_fix;
	info->fix.smem_len = videomemorysize;
	par = info->par;
	par->info = info;

	if (!dio_addr || !cio_addr || !c2io_addr) {
		printk(KERN_WARNING "no IO addresses supplied\n");
		goto err1;
	}
	par->dio_addr = dio_addr;
	par->cio_addr = cio_addr;
	par->c2io_addr = c2io_addr;
	info->flags = FBINFO_FLAG_DEFAULT;

	info->fbdefio = &hecubafb_defio;
	fb_deferred_io_init(info);

	retval = register_framebuffer(info);
	if (retval < 0)
		goto err1;
	platform_set_drvdata(dev, info);

	printk(KERN_INFO
	       "fb%d: Hecuba frame buffer device, using %dK of video memory\n",
	       info->node, videomemorysize >> 10);

	/* this inits the dpy */
	apollo_init_control(par);

	apollo_send_command(par, APOLLO_INIT_DISPLAY);
	apollo_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) {
		apollo_send_command(par, APOLLO_ERASE_DISPLAY);
		apollo_send_data(par, splashval);
	}

	return 0;
err1:
	framebuffer_release(info);
err:
	vfree(videomemory);
	return retval;
}

static int __devexit hecubafb_remove(struct platform_device *dev)
{
	struct fb_info *info = platform_get_drvdata(dev);

	if (info) {
		fb_deferred_io_cleanup(info);
		unregister_framebuffer(info);
		vfree((void __force *)info->screen_base);
		framebuffer_release(info);
	}
	return 0;
}

static struct platform_driver hecubafb_driver = {
	.probe	= hecubafb_probe,
	.remove = hecubafb_remove,
	.driver	= {
		.name	= "hecubafb",
	},
};

static struct platform_device *hecubafb_device;

static int __init hecubafb_init(void)
{
	int ret;

	if (!hecubafb_enable) {
		printk(KERN_ERR "Use hecubafb_enable to enable the device\n");
		return -ENXIO;
	}

	ret = platform_driver_register(&hecubafb_driver);
	if (!ret) {
		hecubafb_device = platform_device_alloc("hecubafb", 0);
		if (hecubafb_device)
			ret = platform_device_add(hecubafb_device);
		else
			ret = -ENOMEM;

		if (ret) {
			platform_device_put(hecubafb_device);
			platform_driver_unregister(&hecubafb_driver);
		}
	}
	return ret;

}

static void __exit hecubafb_exit(void)
{
	platform_device_unregister(hecubafb_device);
	platform_driver_unregister(&hecubafb_driver);
}

module_param(nosplash, uint, 0);
MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
module_param(hecubafb_enable, uint, 0);
MODULE_PARM_DESC(hecubafb_enable, "Enable communication with Hecuba board");
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_param(irq, uint, 0);
MODULE_PARM_DESC(irq, "IRQ for the Hecuba board");

module_init(hecubafb_init);
module_exit(hecubafb_exit);

MODULE_DESCRIPTION("fbdev driver for Hecuba board");
MODULE_AUTHOR("Jaya Kumar");
MODULE_LICENSE("GPL");