summaryrefslogtreecommitdiffstats
path: root/drivers/video/fbdev/cobalt_lcdfb.c
blob: 0ef633e278a1b782ed9a903eb5d0f0848d3d7953 (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
/*
 *  Cobalt/SEAD3 LCD frame buffer driver.
 *
 *  Copyright (C) 2008  Yoichi Yuasa <yuasa@linux-mips.org>
 *  Copyright (C) 2012  MIPS Technologies, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/sched/signal.h>

/*
 * Cursor position address
 * \X  0    1    2  ...  14   15
 * Y+----+----+----+---+----+----+
 * 0|0x00|0x01|0x02|...|0x0e|0x0f|
 *  +----+----+----+---+----+----+
 * 1|0x40|0x41|0x42|...|0x4e|0x4f|
 *  +----+----+----+---+----+----+
 */
#define LCD_DATA_REG_OFFSET	0x10
#define LCD_XRES_MAX		16
#define LCD_YRES_MAX		2
#define LCD_CHARS_MAX		32

#define LCD_CLEAR		0x01
#define LCD_CURSOR_MOVE_HOME	0x02
#define LCD_RESET		0x06
#define LCD_OFF			0x08
#define LCD_CURSOR_OFF		0x0c
#define LCD_CURSOR_BLINK_OFF	0x0e
#define LCD_CURSOR_ON		0x0f
#define LCD_ON			LCD_CURSOR_ON
#define LCD_CURSOR_MOVE_LEFT	0x10
#define LCD_CURSOR_MOVE_RIGHT	0x14
#define LCD_DISPLAY_LEFT	0x18
#define LCD_DISPLAY_RIGHT	0x1c
#define LCD_PRERESET		0x3f	/* execute 4 times continuously */
#define LCD_BUSY		0x80

#define LCD_GRAPHIC_MODE	0x40
#define LCD_TEXT_MODE		0x80
#define LCD_CUR_POS_MASK	0x7f

#define LCD_CUR_POS(x)		((x) & LCD_CUR_POS_MASK)
#define LCD_TEXT_POS(x)		((x) | LCD_TEXT_MODE)

static inline void lcd_write_control(struct fb_info *info, u8 control)
{
	writel((u32)control << 24, info->screen_base);
}

static inline u8 lcd_read_control(struct fb_info *info)
{
	return readl(info->screen_base) >> 24;
}

static inline void lcd_write_data(struct fb_info *info, u8 data)
{
	writel((u32)data << 24, info->screen_base + LCD_DATA_REG_OFFSET);
}

static inline u8 lcd_read_data(struct fb_info *info)
{
	return readl(info->screen_base + LCD_DATA_REG_OFFSET) >> 24;
}

static int lcd_busy_wait(struct fb_info *info)
{
	u8 val = 0;
	int timeout = 10, retval = 0;

	do {
		val = lcd_read_control(info);
		val &= LCD_BUSY;
		if (val != LCD_BUSY)
			break;

		if (msleep_interruptible(1))
			return -EINTR;

		timeout--;
	} while (timeout);

	if (val == LCD_BUSY)
		retval = -EBUSY;

	return retval;
}

static void lcd_clear(struct fb_info *info)
{
	int i;

	for (i = 0; i < 4; i++) {
		udelay(150);

		lcd_write_control(info, LCD_PRERESET);
	}

	udelay(150);

	lcd_write_control(info, LCD_CLEAR);

	udelay(150);

	lcd_write_control(info, LCD_RESET);
}

static const struct fb_fix_screeninfo cobalt_lcdfb_fix = {
	.id		= "cobalt-lcd",
	.type		= FB_TYPE_TEXT,
	.type_aux	= FB_AUX_TEXT_MDA,
	.visual		= FB_VISUAL_MONO01,
	.line_length	= LCD_XRES_MAX,
	.accel		= FB_ACCEL_NONE,
};

static ssize_t cobalt_lcdfb_read(struct fb_info *info, char __user *buf,
				 size_t count, loff_t *ppos)
{
	char src[LCD_CHARS_MAX];
	unsigned long pos;
	int len, retval = 0;

	pos = *ppos;
	if (pos >= LCD_CHARS_MAX || count == 0)
		return 0;

	if (count > LCD_CHARS_MAX)
		count = LCD_CHARS_MAX;

	if (pos + count > LCD_CHARS_MAX)
		count = LCD_CHARS_MAX - pos;

	for (len = 0; len < count; len++) {
		retval = lcd_busy_wait(info);
		if (retval < 0)
			break;

		lcd_write_control(info, LCD_TEXT_POS(pos));

		retval = lcd_busy_wait(info);
		if (retval < 0)
			break;

		src[len] = lcd_read_data(info);
		if (pos == 0x0f)
			pos = 0x40;
		else
			pos++;
	}

	if (retval < 0 && signal_pending(current))
		return -ERESTARTSYS;

	if (copy_to_user(buf, src, len))
		return -EFAULT;

	*ppos += len;

	return len;
}

static ssize_t cobalt_lcdfb_write(struct fb_info *info, const char __user *buf,
				  size_t count, loff_t *ppos)
{
	char dst[LCD_CHARS_MAX];
	unsigned long pos;
	int len, retval = 0;

	pos = *ppos;
	if (pos >= LCD_CHARS_MAX || count == 0)
		return 0;

	if (count > LCD_CHARS_MAX)
		count = LCD_CHARS_MAX;

	if (pos + count > LCD_CHARS_MAX)
		count = LCD_CHARS_MAX - pos;

	if (copy_from_user(dst, buf, count))
		return -EFAULT;

	for (len = 0; len < count; len++) {
		retval = lcd_busy_wait(info);
		if (retval < 0)
			break;

		lcd_write_control(info, LCD_TEXT_POS(pos));

		retval = lcd_busy_wait(info);
		if (retval < 0)
			break;

		lcd_write_data(info, dst[len]);
		if (pos == 0x0f)
			pos = 0x40;
		else
			pos++;
	}

	if (retval < 0 && signal_pending(current))
		return -ERESTARTSYS;

	*ppos += len;

	return len;
}

static int cobalt_lcdfb_blank(int blank_mode, struct fb_info *info)
{
	int retval;

	retval = lcd_busy_wait(info);
	if (retval < 0)
		return retval;

	switch (blank_mode) {
	case FB_BLANK_UNBLANK:
		lcd_write_control(info, LCD_ON);
		break;
	default:
		lcd_write_control(info, LCD_OFF);
		break;
	}

	return 0;
}

static int cobalt_lcdfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
{
	u32 x, y;
	int retval;

	switch (cursor->set) {
	case FB_CUR_SETPOS:
		x = cursor->image.dx;
		y = cursor->image.dy;
		if (x >= LCD_XRES_MAX || y >= LCD_YRES_MAX)
			return -EINVAL;

		retval = lcd_busy_wait(info);
		if (retval < 0)
			return retval;

		lcd_write_control(info,
				  LCD_TEXT_POS(info->fix.line_length * y + x));
		break;
	default:
		return -EINVAL;
	}

	retval = lcd_busy_wait(info);
	if (retval < 0)
		return retval;

	if (cursor->enable)
		lcd_write_control(info, LCD_CURSOR_ON);
	else
		lcd_write_control(info, LCD_CURSOR_OFF);

	return 0;
}

static struct fb_ops cobalt_lcd_fbops = {
	.owner		= THIS_MODULE,
	.fb_read	= cobalt_lcdfb_read,
	.fb_write	= cobalt_lcdfb_write,
	.fb_blank	= cobalt_lcdfb_blank,
	.fb_cursor	= cobalt_lcdfb_cursor,
};

static int cobalt_lcdfb_probe(struct platform_device *dev)
{
	struct fb_info *info;
	struct resource *res;
	int retval;

	info = framebuffer_alloc(0, &dev->dev);
	if (!info)
		return -ENOMEM;

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res) {
		framebuffer_release(info);
		return -EBUSY;
	}

	info->screen_size = resource_size(res);
	info->screen_base = devm_ioremap(&dev->dev, res->start,
					 info->screen_size);
	if (!info->screen_base) {
		framebuffer_release(info);
		return -ENOMEM;
	}

	info->fbops = &cobalt_lcd_fbops;
	info->fix = cobalt_lcdfb_fix;
	info->fix.smem_start = res->start;
	info->fix.smem_len = info->screen_size;
	info->pseudo_palette = NULL;
	info->par = NULL;
	info->flags = FBINFO_DEFAULT;

	retval = register_framebuffer(info);
	if (retval < 0) {
		framebuffer_release(info);
		return retval;
	}

	platform_set_drvdata(dev, info);

	lcd_clear(info);

	fb_info(info, "Cobalt server LCD frame buffer device\n");

	return 0;
}

static int cobalt_lcdfb_remove(struct platform_device *dev)
{
	struct fb_info *info;

	info = platform_get_drvdata(dev);
	if (info) {
		unregister_framebuffer(info);
		framebuffer_release(info);
	}

	return 0;
}

static struct platform_driver cobalt_lcdfb_driver = {
	.probe	= cobalt_lcdfb_probe,
	.remove	= cobalt_lcdfb_remove,
	.driver	= {
		.name	= "cobalt-lcd",
	},
};
module_platform_driver(cobalt_lcdfb_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Yoichi Yuasa");
MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver");