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
28/*
29 * Cursor position address
30 * \X 0 1 2 ... 14 15
31 * Y+----+----+----+---+----+----+
32 * 0|0x00|0x01|0x02|...|0x0e|0x0f|
33 * +----+----+----+---+----+----+
34 * 1|0x40|0x41|0x42|...|0x4e|0x4f|
35 * +----+----+----+---+----+----+
36 */
37#define LCD_DATA_REG_OFFSET 0x10
38#define LCD_XRES_MAX 16
39#define LCD_YRES_MAX 2
40#define LCD_CHARS_MAX 32
41
42#define LCD_CLEAR 0x01
43#define LCD_CURSOR_MOVE_HOME 0x02
44#define LCD_RESET 0x06
45#define LCD_OFF 0x08
46#define LCD_CURSOR_OFF 0x0c
47#define LCD_CURSOR_BLINK_OFF 0x0e
48#define LCD_CURSOR_ON 0x0f
49#define LCD_ON LCD_CURSOR_ON
50#define LCD_CURSOR_MOVE_LEFT 0x10
51#define LCD_CURSOR_MOVE_RIGHT 0x14
52#define LCD_DISPLAY_LEFT 0x18
53#define LCD_DISPLAY_RIGHT 0x1c
54#define LCD_PRERESET 0x3f /* execute 4 times continuously */
55#define LCD_BUSY 0x80
56
57#define LCD_GRAPHIC_MODE 0x40
58#define LCD_TEXT_MODE 0x80
59#define LCD_CUR_POS_MASK 0x7f
60
61#define LCD_CUR_POS(x) ((x) & LCD_CUR_POS_MASK)
62#define LCD_TEXT_POS(x) ((x) | LCD_TEXT_MODE)
63
64static inline void lcd_write_control(struct fb_info *info, u8 control)
65{
66 writel((u32)control << 24, info->screen_base);
67}
68
69static inline u8 lcd_read_control(struct fb_info *info)
70{
71 return readl(info->screen_base) >> 24;
72}
73
74static inline void lcd_write_data(struct fb_info *info, u8 data)
75{
76 writel((u32)data << 24, info->screen_base + LCD_DATA_REG_OFFSET);
77}
78
79static inline u8 lcd_read_data(struct fb_info *info)
80{
81 return readl(info->screen_base + LCD_DATA_REG_OFFSET) >> 24;
82}
83
84static int lcd_busy_wait(struct fb_info *info)
85{
86 u8 val = 0;
87 int timeout = 10, retval = 0;
88
89 do {
90 val = lcd_read_control(info);
91 val &= LCD_BUSY;
92 if (val != LCD_BUSY)
93 break;
94
95 if (msleep_interruptible(1))
96 return -EINTR;
97
98 timeout--;
99 } while (timeout);
100
101 if (val == LCD_BUSY)
102 retval = -EBUSY;
103
104 return retval;
105}
106
107static void lcd_clear(struct fb_info *info)
108{
109 int i;
110
111 for (i = 0; i < 4; i++) {
112 udelay(150);
113
114 lcd_write_control(info, LCD_PRERESET);
115 }
116
117 udelay(150);
118
119 lcd_write_control(info, LCD_CLEAR);
120
121 udelay(150);
122
123 lcd_write_control(info, LCD_RESET);
124}
125
126static struct fb_fix_screeninfo cobalt_lcdfb_fix __devinitdata = {
127 .id = "cobalt-lcd",
128 .type = FB_TYPE_TEXT,
129 .type_aux = FB_AUX_TEXT_MDA,
130 .visual = FB_VISUAL_MONO01,
131 .line_length = LCD_XRES_MAX,
132 .accel = FB_ACCEL_NONE,
133};
134
135static ssize_t cobalt_lcdfb_read(struct fb_info *info, char __user *buf,
136 size_t count, loff_t *ppos)
137{
138 char src[LCD_CHARS_MAX];
139 unsigned long pos;
140 int len, retval = 0;
141
142 pos = *ppos;
143 if (pos >= LCD_CHARS_MAX || count == 0)
144 return 0;
145
146 if (count > LCD_CHARS_MAX)
147 count = LCD_CHARS_MAX;
148
149 if (pos + count > LCD_CHARS_MAX)
150 count = LCD_CHARS_MAX - pos;
151
152 for (len = 0; len < count; len++) {
153 retval = lcd_busy_wait(info);
154 if (retval < 0)
155 break;
156
157 lcd_write_control(info, LCD_TEXT_POS(pos));
158
159 retval = lcd_busy_wait(info);
160 if (retval < 0)
161 break;
162
163 src[len] = lcd_read_data(info);
164 if (pos == 0x0f)
165 pos = 0x40;
166 else
167 pos++;
168 }
169
170 if (retval < 0 && signal_pending(current))
171 return -ERESTARTSYS;
172
173 if (copy_to_user(buf, src, len))
174 return -EFAULT;
175
176 *ppos += len;
177
178 return len;
179}
180
181static ssize_t cobalt_lcdfb_write(struct fb_info *info, const char __user *buf,
182 size_t count, loff_t *ppos)
183{
184 char dst[LCD_CHARS_MAX];
185 unsigned long pos;
186 int len, retval = 0;
187
188 pos = *ppos;
189 if (pos >= LCD_CHARS_MAX || count == 0)
190 return 0;
191
192 if (count > LCD_CHARS_MAX)
193 count = LCD_CHARS_MAX;
194
195 if (pos + count > LCD_CHARS_MAX)
196 count = LCD_CHARS_MAX - pos;
197
198 if (copy_from_user(dst, buf, count))
199 return -EFAULT;
200
201 for (len = 0; len < count; len++) {
202 retval = lcd_busy_wait(info);
203 if (retval < 0)
204 break;
205
206 lcd_write_control(info, LCD_TEXT_POS(pos));
207
208 retval = lcd_busy_wait(info);
209 if (retval < 0)
210 break;
211
212 lcd_write_data(info, dst[len]);
213 if (pos == 0x0f)
214 pos = 0x40;
215 else
216 pos++;
217 }
218
219 if (retval < 0 && signal_pending(current))
220 return -ERESTARTSYS;
221
222 *ppos += len;
223
224 return len;
225}
226
227static int cobalt_lcdfb_blank(int blank_mode, struct fb_info *info)
228{
229 int retval;
230
231 retval = lcd_busy_wait(info);
232 if (retval < 0)
233 return retval;
234
235 switch (blank_mode) {
236 case FB_BLANK_UNBLANK:
237 lcd_write_control(info, LCD_ON);
238 break;
239 default:
240 lcd_write_control(info, LCD_OFF);
241 break;
242 }
243
244 return 0;
245}
246
247static int cobalt_lcdfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
248{
249 u32 x, y;
250 int retval;
251
252 switch (cursor->set) {
253 case FB_CUR_SETPOS:
254 x = cursor->image.dx;
255 y = cursor->image.dy;
256 if (x >= LCD_XRES_MAX || y >= LCD_YRES_MAX)
257 return -EINVAL;
258
259 retval = lcd_busy_wait(info);
260 if (retval < 0)
261 return retval;
262
263 lcd_write_control(info,
264 LCD_TEXT_POS(info->fix.line_length * y + x));
265 break;
266 default:
267 return -EINVAL;
268 }
269
270 retval = lcd_busy_wait(info);
271 if (retval < 0)
272 return retval;
273
274 if (cursor->enable)
275 lcd_write_control(info, LCD_CURSOR_ON);
276 else
277 lcd_write_control(info, LCD_CURSOR_OFF);
278
279 return 0;
280}
281
282static struct fb_ops cobalt_lcd_fbops = {
283 .owner = THIS_MODULE,
284 .fb_read = cobalt_lcdfb_read,
285 .fb_write = cobalt_lcdfb_write,
286 .fb_blank = cobalt_lcdfb_blank,
287 .fb_cursor = cobalt_lcdfb_cursor,
288};
289
290static int __devinit cobalt_lcdfb_probe(struct platform_device *dev)
291{
292 struct fb_info *info;
293 struct resource *res;
294 int retval;
295
296 info = framebuffer_alloc(0, &dev->dev);
297 if (!info)
298 return -ENOMEM;
299
300 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
301 if (!res) {
302 framebuffer_release(info);
303 return -EBUSY;
304 }
305
306 info->screen_size = res->end - res->start + 1;
307 info->screen_base = ioremap(res->start, info->screen_size);
308 info->fbops = &cobalt_lcd_fbops;
309 info->fix = cobalt_lcdfb_fix;
310 info->fix.smem_start = res->start;
311 info->fix.smem_len = info->screen_size;
312 info->pseudo_palette = NULL;
313 info->par = NULL;
314 info->flags = FBINFO_DEFAULT;
315
316 retval = register_framebuffer(info);
317 if (retval < 0) {
318 iounmap(info->screen_base);
319 framebuffer_release(info);
320 return retval;
321 }
322
323 platform_set_drvdata(dev, info);
324
325 lcd_clear(info);
326
327 printk(KERN_INFO "fb%d: Cobalt server LCD frame buffer device\n",
328 info->node);
329
330 return 0;
331}
332
333static int __devexit cobalt_lcdfb_remove(struct platform_device *dev)
334{
335 struct fb_info *info;
336
337 info = platform_get_drvdata(dev);
338 if (info) {
339 iounmap(info->screen_base);
340 unregister_framebuffer(info);
341 framebuffer_release(info);
342 }
343
344 return 0;
345}
346
347static struct platform_driver cobalt_lcdfb_driver = {
348 .probe = cobalt_lcdfb_probe,
349 .remove = __devexit_p(cobalt_lcdfb_remove),
350 .driver = {
351 .name = "cobalt-lcd",
352 .owner = THIS_MODULE,
353 },
354};
355
356static int __init cobalt_lcdfb_init(void)
357{
358 return platform_driver_register(&cobalt_lcdfb_driver);
359}
360
361static void __exit cobalt_lcdfb_exit(void)
362{
363 platform_driver_unregister(&cobalt_lcdfb_driver);
364}
365
366module_init(cobalt_lcdfb_init);
367module_exit(cobalt_lcdfb_exit);
368
369MODULE_LICENSE("GPL v2");
370MODULE_AUTHOR("Yoichi Yuasa");
371MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver");