tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Cobalt server LCD frame buffer driver.
3 *
4 * Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20#include <linux/delay.h>
21#include <linux/fb.h>
22#include <linux/init.h>
23#include <linux/io.h>
24#include <linux/ioport.h>
25#include <linux/uaccess.h>
26#include <linux/platform_device.h>
27#include <linux/module.h>
28
29/*
30 * Cursor position address
31 * \X 0 1 2 ... 14 15
32 * Y+----+----+----+---+----+----+
33 * 0|0x00|0x01|0x02|...|0x0e|0x0f|
34 * +----+----+----+---+----+----+
35 * 1|0x40|0x41|0x42|...|0x4e|0x4f|
36 * +----+----+----+---+----+----+
37 */
38#define LCD_DATA_REG_OFFSET 0x10
39#define LCD_XRES_MAX 16
40#define LCD_YRES_MAX 2
41#define LCD_CHARS_MAX 32
42
43#define LCD_CLEAR 0x01
44#define LCD_CURSOR_MOVE_HOME 0x02
45#define LCD_RESET 0x06
46#define LCD_OFF 0x08
47#define LCD_CURSOR_OFF 0x0c
48#define LCD_CURSOR_BLINK_OFF 0x0e
49#define LCD_CURSOR_ON 0x0f
50#define LCD_ON LCD_CURSOR_ON
51#define LCD_CURSOR_MOVE_LEFT 0x10
52#define LCD_CURSOR_MOVE_RIGHT 0x14
53#define LCD_DISPLAY_LEFT 0x18
54#define LCD_DISPLAY_RIGHT 0x1c
55#define LCD_PRERESET 0x3f /* execute 4 times continuously */
56#define LCD_BUSY 0x80
57
58#define LCD_GRAPHIC_MODE 0x40
59#define LCD_TEXT_MODE 0x80
60#define LCD_CUR_POS_MASK 0x7f
61
62#define LCD_CUR_POS(x) ((x) & LCD_CUR_POS_MASK)
63#define LCD_TEXT_POS(x) ((x) | LCD_TEXT_MODE)
64
65static inline void lcd_write_control(struct fb_info *info, u8 control)
66{
67 writel((u32)control << 24, info->screen_base);
68}
69
70static inline u8 lcd_read_control(struct fb_info *info)
71{
72 return readl(info->screen_base) >> 24;
73}
74
75static inline void lcd_write_data(struct fb_info *info, u8 data)
76{
77 writel((u32)data << 24, info->screen_base + LCD_DATA_REG_OFFSET);
78}
79
80static inline u8 lcd_read_data(struct fb_info *info)
81{
82 return readl(info->screen_base + LCD_DATA_REG_OFFSET) >> 24;
83}
84
85static int lcd_busy_wait(struct fb_info *info)
86{
87 u8 val = 0;
88 int timeout = 10, retval = 0;
89
90 do {
91 val = lcd_read_control(info);
92 val &= LCD_BUSY;
93 if (val != LCD_BUSY)
94 break;
95
96 if (msleep_interruptible(1))
97 return -EINTR;
98
99 timeout--;
100 } while (timeout);
101
102 if (val == LCD_BUSY)
103 retval = -EBUSY;
104
105 return retval;
106}
107
108static void lcd_clear(struct fb_info *info)
109{
110 int i;
111
112 for (i = 0; i < 4; i++) {
113 udelay(150);
114
115 lcd_write_control(info, LCD_PRERESET);
116 }
117
118 udelay(150);
119
120 lcd_write_control(info, LCD_CLEAR);
121
122 udelay(150);
123
124 lcd_write_control(info, LCD_RESET);
125}
126
127static struct fb_fix_screeninfo cobalt_lcdfb_fix __devinitdata = {
128 .id = "cobalt-lcd",
129 .type = FB_TYPE_TEXT,
130 .type_aux = FB_AUX_TEXT_MDA,
131 .visual = FB_VISUAL_MONO01,
132 .line_length = LCD_XRES_MAX,
133 .accel = FB_ACCEL_NONE,
134};
135
136static ssize_t cobalt_lcdfb_read(struct fb_info *info, char __user *buf,
137 size_t count, loff_t *ppos)
138{
139 char src[LCD_CHARS_MAX];
140 unsigned long pos;
141 int len, retval = 0;
142
143 pos = *ppos;
144 if (pos >= LCD_CHARS_MAX || count == 0)
145 return 0;
146
147 if (count > LCD_CHARS_MAX)
148 count = LCD_CHARS_MAX;
149
150 if (pos + count > LCD_CHARS_MAX)
151 count = LCD_CHARS_MAX - pos;
152
153 for (len = 0; len < count; len++) {
154 retval = lcd_busy_wait(info);
155 if (retval < 0)
156 break;
157
158 lcd_write_control(info, LCD_TEXT_POS(pos));
159
160 retval = lcd_busy_wait(info);
161 if (retval < 0)
162 break;
163
164 src[len] = lcd_read_data(info);
165 if (pos == 0x0f)
166 pos = 0x40;
167 else
168 pos++;
169 }
170
171 if (retval < 0 && signal_pending(current))
172 return -ERESTARTSYS;
173
174 if (copy_to_user(buf, src, len))
175 return -EFAULT;
176
177 *ppos += len;
178
179 return len;
180}
181
182static ssize_t cobalt_lcdfb_write(struct fb_info *info, const char __user *buf,
183 size_t count, loff_t *ppos)
184{
185 char dst[LCD_CHARS_MAX];
186 unsigned long pos;
187 int len, retval = 0;
188
189 pos = *ppos;
190 if (pos >= LCD_CHARS_MAX || count == 0)
191 return 0;
192
193 if (count > LCD_CHARS_MAX)
194 count = LCD_CHARS_MAX;
195
196 if (pos + count > LCD_CHARS_MAX)
197 count = LCD_CHARS_MAX - pos;
198
199 if (copy_from_user(dst, buf, count))
200 return -EFAULT;
201
202 for (len = 0; len < count; len++) {
203 retval = lcd_busy_wait(info);
204 if (retval < 0)
205 break;
206
207 lcd_write_control(info, LCD_TEXT_POS(pos));
208
209 retval = lcd_busy_wait(info);
210 if (retval < 0)
211 break;
212
213 lcd_write_data(info, dst[len]);
214 if (pos == 0x0f)
215 pos = 0x40;
216 else
217 pos++;
218 }
219
220 if (retval < 0 && signal_pending(current))
221 return -ERESTARTSYS;
222
223 *ppos += len;
224
225 return len;
226}
227
228static int cobalt_lcdfb_blank(int blank_mode, struct fb_info *info)
229{
230 int retval;
231
232 retval = lcd_busy_wait(info);
233 if (retval < 0)
234 return retval;
235
236 switch (blank_mode) {
237 case FB_BLANK_UNBLANK:
238 lcd_write_control(info, LCD_ON);
239 break;
240 default:
241 lcd_write_control(info, LCD_OFF);
242 break;
243 }
244
245 return 0;
246}
247
248static int cobalt_lcdfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
249{
250 u32 x, y;
251 int retval;
252
253 switch (cursor->set) {
254 case FB_CUR_SETPOS:
255 x = cursor->image.dx;
256 y = cursor->image.dy;
257 if (x >= LCD_XRES_MAX || y >= LCD_YRES_MAX)
258 return -EINVAL;
259
260 retval = lcd_busy_wait(info);
261 if (retval < 0)
262 return retval;
263
264 lcd_write_control(info,
265 LCD_TEXT_POS(info->fix.line_length * y + x));
266 break;
267 default:
268 return -EINVAL;
269 }
270
271 retval = lcd_busy_wait(info);
272 if (retval < 0)
273 return retval;
274
275 if (cursor->enable)
276 lcd_write_control(info, LCD_CURSOR_ON);
277 else
278 lcd_write_control(info, LCD_CURSOR_OFF);
279
280 return 0;
281}
282
283static struct fb_ops cobalt_lcd_fbops = {
284 .owner = THIS_MODULE,
285 .fb_read = cobalt_lcdfb_read,
286 .fb_write = cobalt_lcdfb_write,
287 .fb_blank = cobalt_lcdfb_blank,
288 .fb_cursor = cobalt_lcdfb_cursor,
289};
290
291static int __devinit cobalt_lcdfb_probe(struct platform_device *dev)
292{
293 struct fb_info *info;
294 struct resource *res;
295 int retval;
296
297 info = framebuffer_alloc(0, &dev->dev);
298 if (!info)
299 return -ENOMEM;
300
301 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
302 if (!res) {
303 framebuffer_release(info);
304 return -EBUSY;
305 }
306
307 info->screen_size = resource_size(res);
308 info->screen_base = ioremap(res->start, info->screen_size);
309 info->fbops = &cobalt_lcd_fbops;
310 info->fix = cobalt_lcdfb_fix;
311 info->fix.smem_start = res->start;
312 info->fix.smem_len = info->screen_size;
313 info->pseudo_palette = NULL;
314 info->par = NULL;
315 info->flags = FBINFO_DEFAULT;
316
317 retval = register_framebuffer(info);
318 if (retval < 0) {
319 iounmap(info->screen_base);
320 framebuffer_release(info);
321 return retval;
322 }
323
324 platform_set_drvdata(dev, info);
325
326 lcd_clear(info);
327
328 printk(KERN_INFO "fb%d: Cobalt server LCD frame buffer device\n",
329 info->node);
330
331 return 0;
332}
333
334static int __devexit cobalt_lcdfb_remove(struct platform_device *dev)
335{
336 struct fb_info *info;
337
338 info = platform_get_drvdata(dev);
339 if (info) {
340 iounmap(info->screen_base);
341 unregister_framebuffer(info);
342 framebuffer_release(info);
343 }
344
345 return 0;
346}
347
348static struct platform_driver cobalt_lcdfb_driver = {
349 .probe = cobalt_lcdfb_probe,
350 .remove = __devexit_p(cobalt_lcdfb_remove),
351 .driver = {
352 .name = "cobalt-lcd",
353 .owner = THIS_MODULE,
354 },
355};
356
357static int __init cobalt_lcdfb_init(void)
358{
359 return platform_driver_register(&cobalt_lcdfb_driver);
360}
361
362static void __exit cobalt_lcdfb_exit(void)
363{
364 platform_driver_unregister(&cobalt_lcdfb_driver);
365}
366
367module_init(cobalt_lcdfb_init);
368module_exit(cobalt_lcdfb_exit);
369
370MODULE_LICENSE("GPL v2");
371MODULE_AUTHOR("Yoichi Yuasa");
372MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver");