2 * Cobalt server LCD frame buffer driver.
4 * Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org>
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.
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.
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
20 #include <linux/delay.h>
22 #include <linux/init.h>
24 #include <linux/ioport.h>
25 #include <linux/uaccess.h>
26 #include <linux/platform_device.h>
27 #include <linux/module.h>
30 * Cursor position address
32 * Y+----+----+----+---+----+----+
33 * 0|0x00|0x01|0x02|...|0x0e|0x0f|
34 * +----+----+----+---+----+----+
35 * 1|0x40|0x41|0x42|...|0x4e|0x4f|
36 * +----+----+----+---+----+----+
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
43 #define LCD_CLEAR 0x01
44 #define LCD_CURSOR_MOVE_HOME 0x02
45 #define LCD_RESET 0x06
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 */
58 #define LCD_GRAPHIC_MODE 0x40
59 #define LCD_TEXT_MODE 0x80
60 #define LCD_CUR_POS_MASK 0x7f
62 #define LCD_CUR_POS(x) ((x) & LCD_CUR_POS_MASK)
63 #define LCD_TEXT_POS(x) ((x) | LCD_TEXT_MODE)
65 static inline void lcd_write_control(struct fb_info *info, u8 control)
67 writel((u32)control << 24, info->screen_base);
70 static inline u8 lcd_read_control(struct fb_info *info)
72 return readl(info->screen_base) >> 24;
75 static inline void lcd_write_data(struct fb_info *info, u8 data)
77 writel((u32)data << 24, info->screen_base + LCD_DATA_REG_OFFSET);
80 static inline u8 lcd_read_data(struct fb_info *info)
82 return readl(info->screen_base + LCD_DATA_REG_OFFSET) >> 24;
85 static int lcd_busy_wait(struct fb_info *info)
88 int timeout = 10, retval = 0;
91 val = lcd_read_control(info);
96 if (msleep_interruptible(1))
108 static void lcd_clear(struct fb_info *info)
112 for (i = 0; i < 4; i++) {
115 lcd_write_control(info, LCD_PRERESET);
120 lcd_write_control(info, LCD_CLEAR);
124 lcd_write_control(info, LCD_RESET);
127 static struct fb_fix_screeninfo cobalt_lcdfb_fix __devinitdata = {
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,
136 static ssize_t cobalt_lcdfb_read(struct fb_info *info, char __user *buf,
137 size_t count, loff_t *ppos)
139 char src[LCD_CHARS_MAX];
144 if (pos >= LCD_CHARS_MAX || count == 0)
147 if (count > LCD_CHARS_MAX)
148 count = LCD_CHARS_MAX;
150 if (pos + count > LCD_CHARS_MAX)
151 count = LCD_CHARS_MAX - pos;
153 for (len = 0; len < count; len++) {
154 retval = lcd_busy_wait(info);
158 lcd_write_control(info, LCD_TEXT_POS(pos));
160 retval = lcd_busy_wait(info);
164 src[len] = lcd_read_data(info);
171 if (retval < 0 && signal_pending(current))
174 if (copy_to_user(buf, src, len))
182 static ssize_t cobalt_lcdfb_write(struct fb_info *info, const char __user *buf,
183 size_t count, loff_t *ppos)
185 char dst[LCD_CHARS_MAX];
190 if (pos >= LCD_CHARS_MAX || count == 0)
193 if (count > LCD_CHARS_MAX)
194 count = LCD_CHARS_MAX;
196 if (pos + count > LCD_CHARS_MAX)
197 count = LCD_CHARS_MAX - pos;
199 if (copy_from_user(dst, buf, count))
202 for (len = 0; len < count; len++) {
203 retval = lcd_busy_wait(info);
207 lcd_write_control(info, LCD_TEXT_POS(pos));
209 retval = lcd_busy_wait(info);
213 lcd_write_data(info, dst[len]);
220 if (retval < 0 && signal_pending(current))
228 static int cobalt_lcdfb_blank(int blank_mode, struct fb_info *info)
232 retval = lcd_busy_wait(info);
236 switch (blank_mode) {
237 case FB_BLANK_UNBLANK:
238 lcd_write_control(info, LCD_ON);
241 lcd_write_control(info, LCD_OFF);
248 static int cobalt_lcdfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
253 switch (cursor->set) {
255 x = cursor->image.dx;
256 y = cursor->image.dy;
257 if (x >= LCD_XRES_MAX || y >= LCD_YRES_MAX)
260 retval = lcd_busy_wait(info);
264 lcd_write_control(info,
265 LCD_TEXT_POS(info->fix.line_length * y + x));
271 retval = lcd_busy_wait(info);
276 lcd_write_control(info, LCD_CURSOR_ON);
278 lcd_write_control(info, LCD_CURSOR_OFF);
283 static 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,
291 static int __devinit cobalt_lcdfb_probe(struct platform_device *dev)
293 struct fb_info *info;
294 struct resource *res;
297 info = framebuffer_alloc(0, &dev->dev);
301 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
303 framebuffer_release(info);
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;
315 info->flags = FBINFO_DEFAULT;
317 retval = register_framebuffer(info);
319 iounmap(info->screen_base);
320 framebuffer_release(info);
324 platform_set_drvdata(dev, info);
328 printk(KERN_INFO "fb%d: Cobalt server LCD frame buffer device\n",
334 static int __devexit cobalt_lcdfb_remove(struct platform_device *dev)
336 struct fb_info *info;
338 info = platform_get_drvdata(dev);
340 iounmap(info->screen_base);
341 unregister_framebuffer(info);
342 framebuffer_release(info);
348 static struct platform_driver cobalt_lcdfb_driver = {
349 .probe = cobalt_lcdfb_probe,
350 .remove = __devexit_p(cobalt_lcdfb_remove),
352 .name = "cobalt-lcd",
353 .owner = THIS_MODULE,
357 static int __init cobalt_lcdfb_init(void)
359 return platform_driver_register(&cobalt_lcdfb_driver);
362 static void __exit cobalt_lcdfb_exit(void)
364 platform_driver_unregister(&cobalt_lcdfb_driver);
367 module_init(cobalt_lcdfb_init);
368 module_exit(cobalt_lcdfb_exit);
370 MODULE_LICENSE("GPL v2");
371 MODULE_AUTHOR("Yoichi Yuasa");
372 MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver");