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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / hid / hid-picolcd_fb.c
bloba549c42e8c9025bc55f052260b4e62a3b262962b
1 // SPDX-License-Identifier: GPL-2.0-only
2 /***************************************************************************
3 * Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org> *
4 * *
5 * Based on Logitech G13 driver (v0.4) *
6 * Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu> *
7 * *
8 ***************************************************************************/
9
10 #include <linux/hid.h>
11 #include <linux/vmalloc.h>
12
13 #include <linux/fb.h>
14 #include <linux/module.h>
15
16 #include "hid-picolcd.h"
17
18 /* Framebuffer
19 *
20 * The PicoLCD use a Topway LCD module of 256x64 pixel
21 * This display area is tiled over 4 controllers with 8 tiles
22 * each. Each tile has 8x64 pixel, each data byte representing
23 * a 1-bit wide vertical line of the tile.
24 *
25 * The display can be updated at a tile granularity.
26 *
27 * Chip 1 Chip 2 Chip 3 Chip 4
28 * +----------------+----------------+----------------+----------------+
29 * | Tile 1 | Tile 1 | Tile 1 | Tile 1 |
30 * +----------------+----------------+----------------+----------------+
31 * | Tile 2 | Tile 2 | Tile 2 | Tile 2 |
32 * +----------------+----------------+----------------+----------------+
33 * ...
34 * +----------------+----------------+----------------+----------------+
35 * | Tile 8 | Tile 8 | Tile 8 | Tile 8 |
36 * +----------------+----------------+----------------+----------------+
37 */
38 #define PICOLCDFB_NAME "picolcdfb"
39 #define PICOLCDFB_WIDTH (256)
40 #define PICOLCDFB_HEIGHT (64)
41 #define PICOLCDFB_SIZE (PICOLCDFB_WIDTH * PICOLCDFB_HEIGHT / 8)
42
43 #define PICOLCDFB_UPDATE_RATE_LIMIT 10
44 #define PICOLCDFB_UPDATE_RATE_DEFAULT 2
45
46 /* Framebuffer visual structures */
47 static const struct fb_fix_screeninfo picolcdfb_fix = {
48 .id = PICOLCDFB_NAME,
49 .type = FB_TYPE_PACKED_PIXELS,
50 .visual = FB_VISUAL_MONO01,
51 .xpanstep = 0,
52 .ypanstep = 0,
53 .ywrapstep = 0,
54 .line_length = PICOLCDFB_WIDTH / 8,
55 .accel = FB_ACCEL_NONE,
56 };
57
58 static const struct fb_var_screeninfo picolcdfb_var = {
59 .xres = PICOLCDFB_WIDTH,
60 .yres = PICOLCDFB_HEIGHT,
61 .xres_virtual = PICOLCDFB_WIDTH,
62 .yres_virtual = PICOLCDFB_HEIGHT,
63 .width = 103,
64 .height = 26,
65 .bits_per_pixel = 1,
66 .grayscale = 1,
67 .red = {
68 .offset = 0,
69 .length = 1,
70 .msb_right = 0,
71 },
72 .green = {
73 .offset = 0,
74 .length = 1,
75 .msb_right = 0,
76 },
77 .blue = {
78 .offset = 0,
79 .length = 1,
80 .msb_right = 0,
81 },
82 .transp = {
83 .offset = 0,
84 .length = 0,
85 .msb_right = 0,
86 },
87 };
88
89 /* Send a given tile to PicoLCD */
90 static int picolcd_fb_send_tile(struct picolcd_data *data, u8 *vbitmap,
91 int chip, int tile)
92 {
93 struct hid_report *report1, *report2;
94 unsigned long flags;
95 u8 *tdata;
96 int i;
97
98 report1 = picolcd_out_report(REPORT_LCD_CMD_DATA, data->hdev);
99 if (!report1 || report1->maxfield != 1)
100 return -ENODEV;
101 report2 = picolcd_out_report(REPORT_LCD_DATA, data->hdev);
102 if (!report2 || report2->maxfield != 1)
103 return -ENODEV;
104
105 spin_lock_irqsave(&data->lock, flags);
106 if ((data->status & PICOLCD_FAILED)) {
107 spin_unlock_irqrestore(&data->lock, flags);
108 return -ENODEV;
109 }
110 hid_set_field(report1->field[0], 0, chip << 2);
111 hid_set_field(report1->field[0], 1, 0x02);
112 hid_set_field(report1->field[0], 2, 0x00);
113 hid_set_field(report1->field[0], 3, 0x00);
114 hid_set_field(report1->field[0], 4, 0xb8 | tile);
115 hid_set_field(report1->field[0], 5, 0x00);
116 hid_set_field(report1->field[0], 6, 0x00);
117 hid_set_field(report1->field[0], 7, 0x40);
118 hid_set_field(report1->field[0], 8, 0x00);
119 hid_set_field(report1->field[0], 9, 0x00);
120 hid_set_field(report1->field[0], 10, 32);
121
122 hid_set_field(report2->field[0], 0, (chip << 2) | 0x01);
123 hid_set_field(report2->field[0], 1, 0x00);
124 hid_set_field(report2->field[0], 2, 0x00);
125 hid_set_field(report2->field[0], 3, 32);
126
127 tdata = vbitmap + (tile * 4 + chip) * 64;
128 for (i = 0; i < 64; i++)
129 if (i < 32)
130 hid_set_field(report1->field[0], 11 + i, tdata[i]);
131 else
132 hid_set_field(report2->field[0], 4 + i - 32, tdata[i]);
133
134 hid_hw_request(data->hdev, report1, HID_REQ_SET_REPORT);
135 hid_hw_request(data->hdev, report2, HID_REQ_SET_REPORT);
136 spin_unlock_irqrestore(&data->lock, flags);
137 return 0;
138 }
139
140 /* Translate a single tile*/
141 static int picolcd_fb_update_tile(u8 *vbitmap, const u8 *bitmap, int bpp,
142 int chip, int tile)
143 {
144 int i, b, changed = 0;
145 u8 tdata[64];
146 u8 *vdata = vbitmap + (tile * 4 + chip) * 64;
147
148 if (bpp == 1) {
149 for (b = 7; b >= 0; b--) {
150 const u8 *bdata = bitmap + tile * 256 + chip * 8 + b * 32;
151 for (i = 0; i < 64; i++) {
152 tdata[i] <<= 1;
153 tdata[i] |= (bdata[i/8] >> (i % 8)) & 0x01;
154 }
155 }
156 } else if (bpp == 8) {
157 for (b = 7; b >= 0; b--) {
158 const u8 *bdata = bitmap + (tile * 256 + chip * 8 + b * 32) * 8;
159 for (i = 0; i < 64; i++) {
160 tdata[i] <<= 1;
161 tdata[i] |= (bdata[i] & 0x80) ? 0x01 : 0x00;
162 }
163 }
164 } else {
165 /* Oops, we should never get here! */
166 WARN_ON(1);
167 return 0;
168 }
169
170 for (i = 0; i < 64; i++)
171 if (tdata[i] != vdata[i]) {
172 changed = 1;
173 vdata[i] = tdata[i];
174 }
175 return changed;
176 }
177
178 void picolcd_fb_refresh(struct picolcd_data *data)
179 {
180 if (data->fb_info)
181 schedule_delayed_work(&data->fb_info->deferred_work, 0);
182 }
183
184 /* Reconfigure LCD display */
185 int picolcd_fb_reset(struct picolcd_data *data, int clear)
186 {
187 struct hid_report *report = picolcd_out_report(REPORT_LCD_CMD, data->hdev);
188 struct picolcd_fb_data *fbdata = data->fb_info->par;
189 int i, j;
190 unsigned long flags;
191 static const u8 mapcmd[8] = { 0x00, 0x02, 0x00, 0x64, 0x3f, 0x00, 0x64, 0xc0 };
192
193 if (!report || report->maxfield != 1)
194 return -ENODEV;
195
196 spin_lock_irqsave(&data->lock, flags);
197 for (i = 0; i < 4; i++) {
198 for (j = 0; j < report->field[0]->maxusage; j++)
199 if (j == 0)
200 hid_set_field(report->field[0], j, i << 2);
201 else if (j < sizeof(mapcmd))
202 hid_set_field(report->field[0], j, mapcmd[j]);
203 else
204 hid_set_field(report->field[0], j, 0);
205 hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
206 }
207 spin_unlock_irqrestore(&data->lock, flags);
208
209 if (clear) {
210 memset(fbdata->vbitmap, 0, PICOLCDFB_SIZE);
211 memset(fbdata->bitmap, 0, PICOLCDFB_SIZE*fbdata->bpp);
212 }
213 fbdata->force = 1;
214
215 /* schedule first output of framebuffer */
216 if (fbdata->ready)
217 schedule_delayed_work(&data->fb_info->deferred_work, 0);
218 else
219 fbdata->ready = 1;
220
221 return 0;
222 }
223
224 /* Update fb_vbitmap from the screen_base and send changed tiles to device */
225 static void picolcd_fb_update(struct fb_info *info)
226 {
227 int chip, tile, n;
228 unsigned long flags;
229 struct picolcd_fb_data *fbdata = info->par;
230 struct picolcd_data *data;
231
232 mutex_lock(&info->lock);
233
234 spin_lock_irqsave(&fbdata->lock, flags);
235 if (!fbdata->ready && fbdata->picolcd)
236 picolcd_fb_reset(fbdata->picolcd, 0);
237 spin_unlock_irqrestore(&fbdata->lock, flags);
238
239 /*
240 * Translate the framebuffer into the format needed by the PicoLCD.
241 * See display layout above.
242 * Do this one tile after the other and push those tiles that changed.
243 *
244 * Wait for our IO to complete as otherwise we might flood the queue!
245 */
246 n = 0;
247 for (chip = 0; chip < 4; chip++)
248 for (tile = 0; tile < 8; tile++) {
249 if (!fbdata->force && !picolcd_fb_update_tile(
250 fbdata->vbitmap, fbdata->bitmap,
251 fbdata->bpp, chip, tile))
252 continue;
253 n += 2;
254 if (n >= HID_OUTPUT_FIFO_SIZE / 2) {
255 spin_lock_irqsave(&fbdata->lock, flags);
256 data = fbdata->picolcd;
257 spin_unlock_irqrestore(&fbdata->lock, flags);
258 mutex_unlock(&info->lock);
259 if (!data)
260 return;
261 hid_hw_wait(data->hdev);
262 mutex_lock(&info->lock);
263 n = 0;
264 }
265 spin_lock_irqsave(&fbdata->lock, flags);
266 data = fbdata->picolcd;
267 spin_unlock_irqrestore(&fbdata->lock, flags);
268 if (!data || picolcd_fb_send_tile(data,
269 fbdata->vbitmap, chip, tile))
270 goto out;
271 }
272 fbdata->force = false;
273 if (n) {
274 spin_lock_irqsave(&fbdata->lock, flags);
275 data = fbdata->picolcd;
276 spin_unlock_irqrestore(&fbdata->lock, flags);
277 mutex_unlock(&info->lock);
278 if (data)
279 hid_hw_wait(data->hdev);
280 return;
281 }
282 out:
283 mutex_unlock(&info->lock);
284 }
285
286 /* Stub to call the system default and update the image on the picoLCD */
287 static void picolcd_fb_fillrect(struct fb_info *info,
288 const struct fb_fillrect *rect)
289 {
290 if (!info->par)
291 return;
292 sys_fillrect(info, rect);
293
294 schedule_delayed_work(&info->deferred_work, 0);
295 }
296
297 /* Stub to call the system default and update the image on the picoLCD */
298 static void picolcd_fb_copyarea(struct fb_info *info,
299 const struct fb_copyarea *area)
300 {
301 if (!info->par)
302 return;
303 sys_copyarea(info, area);
304
305 schedule_delayed_work(&info->deferred_work, 0);
306 }
307
308 /* Stub to call the system default and update the image on the picoLCD */
309 static void picolcd_fb_imageblit(struct fb_info *info, const struct fb_image *image)
310 {
311 if (!info->par)
312 return;
313 sys_imageblit(info, image);
314
315 schedule_delayed_work(&info->deferred_work, 0);
316 }
317
318 /*
319 * this is the slow path from userspace. they can seek and write to
320 * the fb. it's inefficient to do anything less than a full screen draw
321 */
322 static ssize_t picolcd_fb_write(struct fb_info *info, const char __user *buf,
323 size_t count, loff_t *ppos)
324 {
325 ssize_t ret;
326 if (!info->par)
327 return -ENODEV;
328 ret = fb_sys_write(info, buf, count, ppos);
329 if (ret >= 0)
330 schedule_delayed_work(&info->deferred_work, 0);
331 return ret;
332 }
333
334 static int picolcd_fb_blank(int blank, struct fb_info *info)
335 {
336 /* We let fb notification do this for us via lcd/backlight device */
337 return 0;
338 }
339
340 static void picolcd_fb_destroy(struct fb_info *info)
341 {
342 struct picolcd_fb_data *fbdata = info->par;
343
344 /* make sure no work is deferred */
345 fb_deferred_io_cleanup(info);
346
347 /* No thridparty should ever unregister our framebuffer! */
348 WARN_ON(fbdata->picolcd != NULL);
349
350 vfree((u8 *)info->fix.smem_start);
351 framebuffer_release(info);
352 }
353
354 static int picolcd_fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
355 {
356 __u32 bpp = var->bits_per_pixel;
357 __u32 activate = var->activate;
358
359 /* only allow 1/8 bit depth (8-bit is grayscale) */
360 *var = picolcdfb_var;
361 var->activate = activate;
362 if (bpp >= 8) {
363 var->bits_per_pixel = 8;
364 var->red.length = 8;
365 var->green.length = 8;
366 var->blue.length = 8;
367 } else {
368 var->bits_per_pixel = 1;
369 var->red.length = 1;
370 var->green.length = 1;
371 var->blue.length = 1;
372 }
373 return 0;
374 }
375
376 static int picolcd_set_par(struct fb_info *info)
377 {
378 struct picolcd_fb_data *fbdata = info->par;
379 u8 *tmp_fb, *o_fb;
380 if (info->var.bits_per_pixel == fbdata->bpp)
381 return 0;
382 /* switch between 1/8 bit depths */
383 if (info->var.bits_per_pixel != 1 && info->var.bits_per_pixel != 8)
384 return -EINVAL;
385
386 o_fb = fbdata->bitmap;
387 tmp_fb = kmalloc_array(PICOLCDFB_SIZE, info->var.bits_per_pixel,
388 GFP_KERNEL);
389 if (!tmp_fb)
390 return -ENOMEM;
391
392 /* translate FB content to new bits-per-pixel */
393 if (info->var.bits_per_pixel == 1) {
394 int i, b;
395 for (i = 0; i < PICOLCDFB_SIZE; i++) {
396 u8 p = 0;
397 for (b = 0; b < 8; b++) {
398 p <<= 1;
399 p |= o_fb[i*8+b] ? 0x01 : 0x00;
400 }
401 tmp_fb[i] = p;
402 }
403 memcpy(o_fb, tmp_fb, PICOLCDFB_SIZE);
404 info->fix.visual = FB_VISUAL_MONO01;
405 info->fix.line_length = PICOLCDFB_WIDTH / 8;
406 } else {
407 int i;
408 memcpy(tmp_fb, o_fb, PICOLCDFB_SIZE);
409 for (i = 0; i < PICOLCDFB_SIZE * 8; i++)
410 o_fb[i] = tmp_fb[i/8] & (0x01 << (7 - i % 8)) ? 0xff : 0x00;
411 info->fix.visual = FB_VISUAL_DIRECTCOLOR;
412 info->fix.line_length = PICOLCDFB_WIDTH;
413 }
414
415 kfree(tmp_fb);
416 fbdata->bpp = info->var.bits_per_pixel;
417 return 0;
418 }
419
420 static const struct fb_ops picolcdfb_ops = {
421 .owner = THIS_MODULE,
422 .fb_destroy = picolcd_fb_destroy,
423 .fb_read = fb_sys_read,
424 .fb_write = picolcd_fb_write,
425 .fb_blank = picolcd_fb_blank,
426 .fb_fillrect = picolcd_fb_fillrect,
427 .fb_copyarea = picolcd_fb_copyarea,
428 .fb_imageblit = picolcd_fb_imageblit,
429 .fb_check_var = picolcd_fb_check_var,
430 .fb_set_par = picolcd_set_par,
431 };
432
433
434 /* Callback from deferred IO workqueue */
435 static void picolcd_fb_deferred_io(struct fb_info *info, struct list_head *pagelist)
436 {
437 picolcd_fb_update(info);
438 }
439
440 static const struct fb_deferred_io picolcd_fb_defio = {
441 .delay = HZ / PICOLCDFB_UPDATE_RATE_DEFAULT,
442 .deferred_io = picolcd_fb_deferred_io,
443 };
444
445
446 /*
447 * The "fb_update_rate" sysfs attribute
448 */
449 static ssize_t picolcd_fb_update_rate_show(struct device *dev,
450 struct device_attribute *attr, char *buf)
451 {
452 struct picolcd_data *data = dev_get_drvdata(dev);
453 struct picolcd_fb_data *fbdata = data->fb_info->par;
454 unsigned i, fb_update_rate = fbdata->update_rate;
455 size_t ret = 0;
456
457 for (i = 1; i <= PICOLCDFB_UPDATE_RATE_LIMIT; i++)
458 if (ret >= PAGE_SIZE)
459 break;
460 else if (i == fb_update_rate)
461 ret += snprintf(buf+ret, PAGE_SIZE-ret, "[%u] ", i);
462 else
463 ret += snprintf(buf+ret, PAGE_SIZE-ret, "%u ", i);
464 if (ret > 0)
465 buf[min(ret, (size_t)PAGE_SIZE)-1] = '\n';
466 return ret;
467 }
468
469 static ssize_t picolcd_fb_update_rate_store(struct device *dev,
470 struct device_attribute *attr, const char *buf, size_t count)
471 {
472 struct picolcd_data *data = dev_get_drvdata(dev);
473 struct picolcd_fb_data *fbdata = data->fb_info->par;
474 int i;
475 unsigned u;
476
477 if (count < 1 || count > 10)
478 return -EINVAL;
479
480 i = sscanf(buf, "%u", &u);
481 if (i != 1)
482 return -EINVAL;
483
484 if (u > PICOLCDFB_UPDATE_RATE_LIMIT)
485 return -ERANGE;
486 else if (u == 0)
487 u = PICOLCDFB_UPDATE_RATE_DEFAULT;
488
489 fbdata->update_rate = u;
490 data->fb_info->fbdefio->delay = HZ / fbdata->update_rate;
491 return count;
492 }
493
494 static DEVICE_ATTR(fb_update_rate, 0664, picolcd_fb_update_rate_show,
495 picolcd_fb_update_rate_store);
496
497 /* initialize Framebuffer device */
498 int picolcd_init_framebuffer(struct picolcd_data *data)
499 {
500 struct device *dev = &data->hdev->dev;
501 struct fb_info *info = NULL;
502 struct picolcd_fb_data *fbdata = NULL;
503 int i, error = -ENOMEM;
504 u32 *palette;
505
506 /* The extra memory is:
507 * - 256*u32 for pseudo_palette
508 * - struct fb_deferred_io
509 */
510 info = framebuffer_alloc(256 * sizeof(u32) +
511 sizeof(struct fb_deferred_io) +
512 sizeof(struct picolcd_fb_data) +
513 PICOLCDFB_SIZE, dev);
514 if (!info)
515 goto err_nomem;
516
517 info->fbdefio = info->par;
518 *info->fbdefio = picolcd_fb_defio;
519 info->par += sizeof(struct fb_deferred_io);
520 palette = info->par;
521 info->par += 256 * sizeof(u32);
522 for (i = 0; i < 256; i++)
523 palette[i] = i > 0 && i < 16 ? 0xff : 0;
524 info->pseudo_palette = palette;
525 info->fbops = &picolcdfb_ops;
526 info->var = picolcdfb_var;
527 info->fix = picolcdfb_fix;
528 info->fix.smem_len = PICOLCDFB_SIZE*8;
529 info->flags = FBINFO_FLAG_DEFAULT;
530
531 fbdata = info->par;
532 spin_lock_init(&fbdata->lock);
533 fbdata->picolcd = data;
534 fbdata->update_rate = PICOLCDFB_UPDATE_RATE_DEFAULT;
535 fbdata->bpp = picolcdfb_var.bits_per_pixel;
536 fbdata->force = 1;
537 fbdata->vbitmap = info->par + sizeof(struct picolcd_fb_data);
538 fbdata->bitmap = vmalloc(PICOLCDFB_SIZE*8);
539 if (fbdata->bitmap == NULL) {
540 dev_err(dev, "can't get a free page for framebuffer\n");
541 goto err_nomem;
542 }
543 info->screen_base = (char __force __iomem *)fbdata->bitmap;
544 info->fix.smem_start = (unsigned long)fbdata->bitmap;
545 memset(fbdata->vbitmap, 0xff, PICOLCDFB_SIZE);
546 data->fb_info = info;
547
548 error = picolcd_fb_reset(data, 1);
549 if (error) {
550 dev_err(dev, "failed to configure display\n");
551 goto err_cleanup;
552 }
553
554 error = device_create_file(dev, &dev_attr_fb_update_rate);
555 if (error) {
556 dev_err(dev, "failed to create sysfs attributes\n");
557 goto err_cleanup;
558 }
559
560 fb_deferred_io_init(info);
561 error = register_framebuffer(info);
562 if (error) {
563 dev_err(dev, "failed to register framebuffer\n");
564 goto err_sysfs;
565 }
566 return 0;
567
568 err_sysfs:
569 device_remove_file(dev, &dev_attr_fb_update_rate);
570 fb_deferred_io_cleanup(info);
571 err_cleanup:
572 data->fb_info = NULL;
573
574 err_nomem:
575 if (fbdata)
576 vfree(fbdata->bitmap);
577 framebuffer_release(info);
578 return error;
579 }
580
581 void picolcd_exit_framebuffer(struct picolcd_data *data)
582 {
583 struct fb_info *info = data->fb_info;
584 struct picolcd_fb_data *fbdata;
585 unsigned long flags;
586
587 if (!info)
588 return;
589
590 device_remove_file(&data->hdev->dev, &dev_attr_fb_update_rate);
591 fbdata = info->par;
592
593 /* disconnect framebuffer from HID dev */
594 spin_lock_irqsave(&fbdata->lock, flags);
595 fbdata->picolcd = NULL;
596 spin_unlock_irqrestore(&fbdata->lock, flags);
597
598 /* make sure there is no running update - thus that fbdata->picolcd
599 * once obtained under lock is guaranteed not to get free() under
600 * the feet of the deferred work */
601 flush_delayed_work(&info->deferred_work);
602
603 data->fb_info = NULL;
604 unregister_framebuffer(info);
605 }
Linux with added FPC-III support