summaryrefslogtreecommitdiffstats
path: root/drivers/video/hecubafb.c
blob: f64120ec91921cc3817e4839f3706a1671ef5b0a (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
/*
 * linux/drivers/video/hecubafb.c -- FB driver for Hecuba/Apollo 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 architecture.
 * The actual display chip is called Apollo and the interface electronics
 * it needs is called Hecuba.
 *
 * It is intended to be architecture independent. A board specific driver
 * must be used to perform all the physical IO interactions. An example
 * is provided as n411.c
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.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 <linux/uaccess.h>

#include <video/hecubafb.h>

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

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

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

/* main hecubafb functions */

static void apollo_send_data(struct hecubafb_par *par, unsigned char data)
{
	/* set data */
	par->board->set_data(par, data);

	/* set DS low */
	par->board->set_ctl(par, HCB_DS_BIT, 0);

	/* wait for ack */
	par->board->wait_for_ack(par, 0);

	/* set DS hi */
	par->board->set_ctl(par, HCB_DS_BIT, 1);

	/* wait for ack to clear */
	par->board->wait_for_ack(par, 1);
}

static void apollo_send_command(struct hecubafb_par *par, unsigned char data)
{
	/* command so set CD to high */
	par->board->set_ctl(par, HCB_CD_BIT, 1);

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

	/* clear CD back to low */
	par->board->set_ctl(par, HCB_CD_BIT, 0);
}

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, APOLLO_START_NEW_IMG);

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

	apollo_send_command(par, APOLLO_STOP_IMG_DATA);
	apollo_send_command(par, APOLLO_DISPLAY_IMG);
}

/* 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;

	sys_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;

	sys_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;

	sys_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 fb_info *info, const char __user *buf,
				size_t count, loff_t *ppos)
{
	struct hecubafb_par *par = info->par;
	unsigned long p = *ppos;
	void *dst;
	int err = 0;
	unsigned long total_size;

	if (info->state != FBINFO_STATE_RUNNING)
		return -EPERM;

	total_size = info->fix.smem_len;

	if (p > total_size)
		return -EFBIG;

	if (count > total_size) {
		err = -EFBIG;
		count = total_size;
	}

	if (count + p > total_size) {
		if (!err)
			err = -ENOSPC;

		count = total_size - p;
	}

	dst = (void __force *) (info->screen_base + p);

	if (copy_from_user(dst, buf, count))
		err = -EFAULT;

	if  (!err)
		*ppos += count;

	hecubafb_dpy_update(par);

	return (err) ? err : count;
}

static struct fb_ops hecubafb_ops = {
	.owner		= THIS_MODULE,
	.fb_read        = fb_sys_read,
	.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 hecubafb_probe(struct platform_device *dev)
{
	struct fb_info *info;
	struct hecuba_board *board;
	int retval = -ENOMEM;
	int videomemorysize;
	unsigned char *videomemory;
	struct hecubafb_par *par;

	/* pick up board specific routines */
	board = dev->dev.platform_data;
	if (!board)
		return -EINVAL;

	/* try to count device specific driver, if can't, platform recalls */
	if (!try_module_get(board->owner))
		return -ENODEV;

	videomemorysize = (DPY_W*DPY_H)/8;

	videomemory = vzalloc(videomemorysize);
	if (!videomemory)
		goto err_videomem_alloc;

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

	info->screen_base = (char __force __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;
	par->board = board;
	par->send_command = apollo_send_command;
	par->send_data = apollo_send_data;

	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;

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

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

	fb_info(info, "Hecuba frame buffer device, using %dK of video memory\n",
		videomemorysize >> 10);

	/* this inits the dpy */
	retval = par->board->init(par);
	if (retval < 0)
		goto err_fbreg;

	return 0;
err_fbreg:
	framebuffer_release(info);
err_fballoc:
	vfree(videomemory);
err_videomem_alloc:
	module_put(board->owner);
	return retval;
}

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

	if (info) {
		struct hecubafb_par *par = info->par;
		fb_deferred_io_cleanup(info);
		unregister_framebuffer(info);
		vfree((void __force *)info->screen_base);
		if (par->board->remove)
			par->board->remove(par);
		module_put(par->board->owner);
		framebuffer_release(info);
	}
	return 0;
}

static struct platform_driver hecubafb_driver = {
	.probe	= hecubafb_probe,
	.remove = hecubafb_remove,
	.driver	= {
		.owner	= THIS_MODULE,
		.name	= "hecubafb",
	},
};
module_platform_driver(hecubafb_driver);

MODULE_DESCRIPTION("fbdev driver for Hecuba/Apollo controller");
MODULE_AUTHOR("Jaya Kumar");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud