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8#include <linux/delay.h>
9#include <linux/fb.h>
10#include <linux/init.h>
11#include <linux/io.h>
12#include <linux/ioport.h>
13#include <linux/uaccess.h>
14#include <linux/platform_device.h>
15#include <linux/module.h>
16#include <linux/sched/signal.h>
17
18
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21
22
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24
25
26
27#define LCD_DATA_REG_OFFSET 0x10
28#define LCD_XRES_MAX 16
29#define LCD_YRES_MAX 2
30#define LCD_CHARS_MAX 32
31
32#define LCD_CLEAR 0x01
33#define LCD_CURSOR_MOVE_HOME 0x02
34#define LCD_RESET 0x06
35#define LCD_OFF 0x08
36#define LCD_CURSOR_OFF 0x0c
37#define LCD_CURSOR_BLINK_OFF 0x0e
38#define LCD_CURSOR_ON 0x0f
39#define LCD_ON LCD_CURSOR_ON
40#define LCD_CURSOR_MOVE_LEFT 0x10
41#define LCD_CURSOR_MOVE_RIGHT 0x14
42#define LCD_DISPLAY_LEFT 0x18
43#define LCD_DISPLAY_RIGHT 0x1c
44#define LCD_PRERESET 0x3f
45#define LCD_BUSY 0x80
46
47#define LCD_GRAPHIC_MODE 0x40
48#define LCD_TEXT_MODE 0x80
49#define LCD_CUR_POS_MASK 0x7f
50
51#define LCD_CUR_POS(x) ((x) & LCD_CUR_POS_MASK)
52#define LCD_TEXT_POS(x) ((x) | LCD_TEXT_MODE)
53
54static inline void lcd_write_control(struct fb_info *info, u8 control)
55{
56 writel((u32)control << 24, info->screen_base);
57}
58
59static inline u8 lcd_read_control(struct fb_info *info)
60{
61 return readl(info->screen_base) >> 24;
62}
63
64static inline void lcd_write_data(struct fb_info *info, u8 data)
65{
66 writel((u32)data << 24, info->screen_base + LCD_DATA_REG_OFFSET);
67}
68
69static inline u8 lcd_read_data(struct fb_info *info)
70{
71 return readl(info->screen_base + LCD_DATA_REG_OFFSET) >> 24;
72}
73
74static int lcd_busy_wait(struct fb_info *info)
75{
76 u8 val = 0;
77 int timeout = 10, retval = 0;
78
79 do {
80 val = lcd_read_control(info);
81 val &= LCD_BUSY;
82 if (val != LCD_BUSY)
83 break;
84
85 if (msleep_interruptible(1))
86 return -EINTR;
87
88 timeout--;
89 } while (timeout);
90
91 if (val == LCD_BUSY)
92 retval = -EBUSY;
93
94 return retval;
95}
96
97static void lcd_clear(struct fb_info *info)
98{
99 int i;
100
101 for (i = 0; i < 4; i++) {
102 udelay(150);
103
104 lcd_write_control(info, LCD_PRERESET);
105 }
106
107 udelay(150);
108
109 lcd_write_control(info, LCD_CLEAR);
110
111 udelay(150);
112
113 lcd_write_control(info, LCD_RESET);
114}
115
116static const struct fb_fix_screeninfo cobalt_lcdfb_fix = {
117 .id = "cobalt-lcd",
118 .type = FB_TYPE_TEXT,
119 .type_aux = FB_AUX_TEXT_MDA,
120 .visual = FB_VISUAL_MONO01,
121 .line_length = LCD_XRES_MAX,
122 .accel = FB_ACCEL_NONE,
123};
124
125static ssize_t cobalt_lcdfb_read(struct fb_info *info, char __user *buf,
126 size_t count, loff_t *ppos)
127{
128 char src[LCD_CHARS_MAX];
129 unsigned long pos;
130 int len, retval = 0;
131
132 pos = *ppos;
133 if (pos >= LCD_CHARS_MAX || count == 0)
134 return 0;
135
136 if (count > LCD_CHARS_MAX)
137 count = LCD_CHARS_MAX;
138
139 if (pos + count > LCD_CHARS_MAX)
140 count = LCD_CHARS_MAX - pos;
141
142 for (len = 0; len < count; len++) {
143 retval = lcd_busy_wait(info);
144 if (retval < 0)
145 break;
146
147 lcd_write_control(info, LCD_TEXT_POS(pos));
148
149 retval = lcd_busy_wait(info);
150 if (retval < 0)
151 break;
152
153 src[len] = lcd_read_data(info);
154 if (pos == 0x0f)
155 pos = 0x40;
156 else
157 pos++;
158 }
159
160 if (retval < 0 && signal_pending(current))
161 return -ERESTARTSYS;
162
163 if (copy_to_user(buf, src, len))
164 return -EFAULT;
165
166 *ppos += len;
167
168 return len;
169}
170
171static ssize_t cobalt_lcdfb_write(struct fb_info *info, const char __user *buf,
172 size_t count, loff_t *ppos)
173{
174 char dst[LCD_CHARS_MAX];
175 unsigned long pos;
176 int len, retval = 0;
177
178 pos = *ppos;
179 if (pos >= LCD_CHARS_MAX || count == 0)
180 return 0;
181
182 if (count > LCD_CHARS_MAX)
183 count = LCD_CHARS_MAX;
184
185 if (pos + count > LCD_CHARS_MAX)
186 count = LCD_CHARS_MAX - pos;
187
188 if (copy_from_user(dst, buf, count))
189 return -EFAULT;
190
191 for (len = 0; len < count; len++) {
192 retval = lcd_busy_wait(info);
193 if (retval < 0)
194 break;
195
196 lcd_write_control(info, LCD_TEXT_POS(pos));
197
198 retval = lcd_busy_wait(info);
199 if (retval < 0)
200 break;
201
202 lcd_write_data(info, dst[len]);
203 if (pos == 0x0f)
204 pos = 0x40;
205 else
206 pos++;
207 }
208
209 if (retval < 0 && signal_pending(current))
210 return -ERESTARTSYS;
211
212 *ppos += len;
213
214 return len;
215}
216
217static int cobalt_lcdfb_blank(int blank_mode, struct fb_info *info)
218{
219 int retval;
220
221 retval = lcd_busy_wait(info);
222 if (retval < 0)
223 return retval;
224
225 switch (blank_mode) {
226 case FB_BLANK_UNBLANK:
227 lcd_write_control(info, LCD_ON);
228 break;
229 default:
230 lcd_write_control(info, LCD_OFF);
231 break;
232 }
233
234 return 0;
235}
236
237static int cobalt_lcdfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
238{
239 u32 x, y;
240 int retval;
241
242 switch (cursor->set) {
243 case FB_CUR_SETPOS:
244 x = cursor->image.dx;
245 y = cursor->image.dy;
246 if (x >= LCD_XRES_MAX || y >= LCD_YRES_MAX)
247 return -EINVAL;
248
249 retval = lcd_busy_wait(info);
250 if (retval < 0)
251 return retval;
252
253 lcd_write_control(info,
254 LCD_TEXT_POS(info->fix.line_length * y + x));
255 break;
256 default:
257 return -EINVAL;
258 }
259
260 retval = lcd_busy_wait(info);
261 if (retval < 0)
262 return retval;
263
264 if (cursor->enable)
265 lcd_write_control(info, LCD_CURSOR_ON);
266 else
267 lcd_write_control(info, LCD_CURSOR_OFF);
268
269 return 0;
270}
271
272static struct fb_ops cobalt_lcd_fbops = {
273 .owner = THIS_MODULE,
274 .fb_read = cobalt_lcdfb_read,
275 .fb_write = cobalt_lcdfb_write,
276 .fb_blank = cobalt_lcdfb_blank,
277 .fb_cursor = cobalt_lcdfb_cursor,
278};
279
280static int cobalt_lcdfb_probe(struct platform_device *dev)
281{
282 struct fb_info *info;
283 struct resource *res;
284 int retval;
285
286 info = framebuffer_alloc(0, &dev->dev);
287 if (!info)
288 return -ENOMEM;
289
290 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
291 if (!res) {
292 framebuffer_release(info);
293 return -EBUSY;
294 }
295
296 info->screen_size = resource_size(res);
297 info->screen_base = devm_ioremap(&dev->dev, res->start,
298 info->screen_size);
299 if (!info->screen_base) {
300 framebuffer_release(info);
301 return -ENOMEM;
302 }
303
304 info->fbops = &cobalt_lcd_fbops;
305 info->fix = cobalt_lcdfb_fix;
306 info->fix.smem_start = res->start;
307 info->fix.smem_len = info->screen_size;
308 info->pseudo_palette = NULL;
309 info->par = NULL;
310 info->flags = FBINFO_DEFAULT;
311
312 retval = register_framebuffer(info);
313 if (retval < 0) {
314 framebuffer_release(info);
315 return retval;
316 }
317
318 platform_set_drvdata(dev, info);
319
320 lcd_clear(info);
321
322 fb_info(info, "Cobalt server LCD frame buffer device\n");
323
324 return 0;
325}
326
327static int cobalt_lcdfb_remove(struct platform_device *dev)
328{
329 struct fb_info *info;
330
331 info = platform_get_drvdata(dev);
332 if (info) {
333 unregister_framebuffer(info);
334 framebuffer_release(info);
335 }
336
337 return 0;
338}
339
340static struct platform_driver cobalt_lcdfb_driver = {
341 .probe = cobalt_lcdfb_probe,
342 .remove = cobalt_lcdfb_remove,
343 .driver = {
344 .name = "cobalt-lcd",
345 },
346};
347module_platform_driver(cobalt_lcdfb_driver);
348
349MODULE_LICENSE("GPL v2");
350MODULE_AUTHOR("Yoichi Yuasa");
351MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver");
352
