summaryrefslogtreecommitdiffstats
path: root/drivers/video/fbdev/simplefb.c
blob: 61f799a515dc797e36aaa3f203f76153f59d802e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
/*
 * Simplest possible simple frame-buffer driver, as a platform device
 *
 * Copyright (c) 2013, Stephen Warren
 *
 * Based on q40fb.c, which was:
 * Copyright (C) 2001 Richard Zidlicky <rz@linux-m68k.org>
 *
 * Also based on offb.c, which was:
 * Copyright (C) 1997 Geert Uytterhoeven
 * Copyright (C) 1996 Paul Mackerras
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/errno.h>
#include <linux/fb.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_data/simplefb.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/parser.h>
#include <linux/regulator/consumer.h>

static const struct fb_fix_screeninfo simplefb_fix = {
	.id		= "simple",
	.type		= FB_TYPE_PACKED_PIXELS,
	.visual		= FB_VISUAL_TRUECOLOR,
	.accel		= FB_ACCEL_NONE,
};

static const struct fb_var_screeninfo simplefb_var = {
	.height		= -1,
	.width		= -1,
	.activate	= FB_ACTIVATE_NOW,
	.vmode		= FB_VMODE_NONINTERLACED,
};

#define PSEUDO_PALETTE_SIZE 16

static int simplefb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
			      u_int transp, struct fb_info *info)
{
	u32 *pal = info->pseudo_palette;
	u32 cr = red >> (16 - info->var.red.length);
	u32 cg = green >> (16 - info->var.green.length);
	u32 cb = blue >> (16 - info->var.blue.length);
	u32 value;

	if (regno >= PSEUDO_PALETTE_SIZE)
		return -EINVAL;

	value = (cr << info->var.red.offset) |
		(cg << info->var.green.offset) |
		(cb << info->var.blue.offset);
	if (info->var.transp.length > 0) {
		u32 mask = (1 << info->var.transp.length) - 1;
		mask <<= info->var.transp.offset;
		value |= mask;
	}
	pal[regno] = value;

	return 0;
}

struct simplefb_par;
static void simplefb_clocks_destroy(struct simplefb_par *par);
static void simplefb_regulators_destroy(struct simplefb_par *par);

static void simplefb_destroy(struct fb_info *info)
{
	simplefb_regulators_destroy(info->par);
	simplefb_clocks_destroy(info->par);
	if (info->screen_base)
		iounmap(info->screen_base);
}

static struct fb_ops simplefb_ops = {
	.owner		= THIS_MODULE,
	.fb_destroy	= simplefb_destroy,
	.fb_setcolreg	= simplefb_setcolreg,
	.fb_fillrect	= cfb_fillrect,
	.fb_copyarea	= cfb_copyarea,
	.fb_imageblit	= cfb_imageblit,
};

static struct simplefb_format simplefb_formats[] = SIMPLEFB_FORMATS;

struct simplefb_params {
	u32 width;
	u32 height;
	u32 stride;
	struct simplefb_format *format;
};

static int simplefb_parse_dt(struct platform_device *pdev,
			   struct simplefb_params *params)
{
	struct device_node *np = pdev->dev.of_node;
	int ret;
	const char *format;
	int i;

	ret = of_property_read_u32(np, "width", &params->width);
	if (ret) {
		dev_err(&pdev->dev, "Can't parse width property\n");
		return ret;
	}

	ret = of_property_read_u32(np, "height", &params->height);
	if (ret) {
		dev_err(&pdev->dev, "Can't parse height property\n");
		return ret;
	}

	ret = of_property_read_u32(np, "stride", &params->stride);
	if (ret) {
		dev_err(&pdev->dev, "Can't parse stride property\n");
		return ret;
	}

	ret = of_property_read_string(np, "format", &format);
	if (ret) {
		dev_err(&pdev->dev, "Can't parse format property\n");
		return ret;
	}
	params->format = NULL;
	for (i = 0; i < ARRAY_SIZE(simplefb_formats); i++) {
		if (strcmp(format, simplefb_formats[i].name))
			continue;
		params->format = &simplefb_formats[i];
		break;
	}
	if (!params->format) {
		dev_err(&pdev->dev, "Invalid format value\n");
		return -EINVAL;
	}

	return 0;
}

static int simplefb_parse_pd(struct platform_device *pdev,
			     struct simplefb_params *params)
{
	struct simplefb_platform_data *pd = dev_get_platdata(&pdev->dev);
	int i;

	params->width = pd->width;
	params->height = pd->height;
	params->stride = pd->stride;

	params->format = NULL;
	for (i = 0; i < ARRAY_SIZE(simplefb_formats); i++) {
		if (strcmp(pd->format, simplefb_formats[i].name))
			continue;

		params->format = &simplefb_formats[i];
		break;
	}

	if (!params->format) {
		dev_err(&pdev->dev, "Invalid format value\n");
		return -EINVAL;
	}

	return 0;
}

struct simplefb_par {
	u32 palette[PSEUDO_PALETTE_SIZE];
#if defined CONFIG_OF && defined CONFIG_COMMON_CLK
	unsigned int clk_count;
	struct clk **clks;
#endif
#if defined CONFIG_OF && defined CONFIG_REGULATOR
	u32 regulator_count;
	struct regulator **regulators;
#endif
};

#if defined CONFIG_OF && defined CONFIG_COMMON_CLK
/*
 * Clock handling code.
 *
 * Here we handle the clocks property of our "simple-framebuffer" dt node.
 * This is necessary so that we can make sure that any clocks needed by
 * the display engine that the bootloader set up for us (and for which it
 * provided a simplefb dt node), stay up, for the life of the simplefb
 * driver.
 *
 * When the driver unloads, we cleanly disable, and then release the clocks.
 *
 * We only complain about errors here, no action is taken as the most likely
 * error can only happen due to a mismatch between the bootloader which set
 * up simplefb, and the clock definitions in the device tree. Chances are
 * that there are no adverse effects, and if there are, a clean teardown of
 * the fb probe will not help us much either. So just complain and carry on,
 * and hope that the user actually gets a working fb at the end of things.
 */
static int simplefb_clocks_init(struct simplefb_par *par,
				struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct clk *clock;
	int i, ret;

	if (dev_get_platdata(&pdev->dev) || !np)
		return 0;

	par->clk_count = of_clk_get_parent_count(np);
	if (!par->clk_count)
		return 0;

	par->clks = kcalloc(par->clk_count, sizeof(struct clk *), GFP_KERNEL);
	if (!par->clks)
		return -ENOMEM;

	for (i = 0; i < par->clk_count; i++) {
		clock = of_clk_get(np, i);
		if (IS_ERR(clock)) {
			if (PTR_ERR(clock) == -EPROBE_DEFER) {
				while (--i >= 0) {
					if (par->clks[i])
						clk_put(par->clks[i]);
				}
				kfree(par->clks);
				return -EPROBE_DEFER;
			}
			dev_err(&pdev->dev, "%s: clock %d not found: %ld\n",
				__func__, i, PTR_ERR(clock));
			continue;
		}
		par->clks[i] = clock;
	}

	for (i = 0; i < par->clk_count; i++) {
		if (par->clks[i]) {
			ret = clk_prepare_enable(par->clks[i]);
			if (ret) {
				dev_err(&pdev->dev,
					"%s: failed to enable clock %d: %d\n",
					__func__, i, ret);
				clk_put(par->clks[i]);
				par->clks[i] = NULL;
			}
		}
	}

	return 0;
}

static void simplefb_clocks_destroy(struct simplefb_par *par)
{
	int i;

	if (!par->clks)
		return;

	for (i = 0; i < par->clk_count; i++) {
		if (par->clks[i]) {
			clk_disable_unprepare(par->clks[i]);
			clk_put(par->clks[i]);
		}
	}

	kfree(par->clks);
}
#else
static int simplefb_clocks_init(struct simplefb_par *par,
	struct platform_device *pdev) { return 0; }
static void simplefb_clocks_destroy(struct simplefb_par *par) { }
#endif

#if defined CONFIG_OF && defined CONFIG_REGULATOR

#define SUPPLY_SUFFIX "-supply"

/*
 * Regulator handling code.
 *
 * Here we handle the num-supplies and vin*-supply properties of our
 * "simple-framebuffer" dt node. This is necessary so that we can make sure
 * that any regulators needed by the display hardware that the bootloader
 * set up for us (and for which it provided a simplefb dt node), stay up,
 * for the life of the simplefb driver.
 *
 * When the driver unloads, we cleanly disable, and then release the
 * regulators.
 *
 * We only complain about errors here, no action is taken as the most likely
 * error can only happen due to a mismatch between the bootloader which set
 * up simplefb, and the regulator definitions in the device tree. Chances are
 * that there are no adverse effects, and if there are, a clean teardown of
 * the fb probe will not help us much either. So just complain and carry on,
 * and hope that the user actually gets a working fb at the end of things.
 */
static int simplefb_regulators_init(struct simplefb_par *par,
	struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct property *prop;
	struct regulator *regulator;
	const char *p;
	int count = 0, i = 0, ret;

	if (dev_get_platdata(&pdev->dev) || !np)
		return 0;

	/* Count the number of regulator supplies */
	for_each_property_of_node(np, prop) {
		p = strstr(prop->name, SUPPLY_SUFFIX);
		if (p && p != prop->name)
			count++;
	}

	if (!count)
		return 0;

	par->regulators = devm_kcalloc(&pdev->dev, count,
				       sizeof(struct regulator *), GFP_KERNEL);
	if (!par->regulators)
		return -ENOMEM;

	/* Get all the regulators */
	for_each_property_of_node(np, prop) {
		char name[32]; /* 32 is max size of property name */

		p = strstr(prop->name, SUPPLY_SUFFIX);
		if (!p || p == prop->name)
			continue;

		strlcpy(name, prop->name,
			strlen(prop->name) - strlen(SUPPLY_SUFFIX) + 1);
		regulator = devm_regulator_get_optional(&pdev->dev, name);
		if (IS_ERR(regulator)) {
			if (PTR_ERR(regulator) == -EPROBE_DEFER)
				return -EPROBE_DEFER;
			dev_err(&pdev->dev, "regulator %s not found: %ld\n",
				name, PTR_ERR(regulator));
			continue;
		}
		par->regulators[i++] = regulator;
	}
	par->regulator_count = i;

	/* Enable all the regulators */
	for (i = 0; i < par->regulator_count; i++) {
		ret = regulator_enable(par->regulators[i]);
		if (ret) {
			dev_err(&pdev->dev,
				"failed to enable regulator %d: %d\n",
				i, ret);
			devm_regulator_put(par->regulators[i]);
			par->regulators[i] = NULL;
		}
	}

	return 0;
}

static void simplefb_regulators_destroy(struct simplefb_par *par)
{
	int i;

	if (!par->regulators)
		return;

	for (i = 0; i < par->regulator_count; i++)
		if (par->regulators[i])
			regulator_disable(par->regulators[i]);
}
#else
static int simplefb_regulators_init(struct simplefb_par *par,
	struct platform_device *pdev) { return 0; }
static void simplefb_regulators_destroy(struct simplefb_par *par) { }
#endif

static int simplefb_probe(struct platform_device *pdev)
{
	int ret;
	struct simplefb_params params;
	struct fb_info *info;
	struct simplefb_par *par;
	struct resource *mem;

	if (fb_get_options("simplefb", NULL))
		return -ENODEV;

	ret = -ENODEV;
	if (dev_get_platdata(&pdev->dev))
		ret = simplefb_parse_pd(pdev, &params);
	else if (pdev->dev.of_node)
		ret = simplefb_parse_dt(pdev, &params);

	if (ret)
		return ret;

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!mem) {
		dev_err(&pdev->dev, "No memory resource\n");
		return -EINVAL;
	}

	info = framebuffer_alloc(sizeof(struct simplefb_par), &pdev->dev);
	if (!info)
		return -ENOMEM;
	platform_set_drvdata(pdev, info);

	par = info->par;

	info->fix = simplefb_fix;
	info->fix.smem_start = mem->start;
	info->fix.smem_len = resource_size(mem);
	info->fix.line_length = params.stride;

	info->var = simplefb_var;
	info->var.xres = params.width;
	info->var.yres = params.height;
	info->var.xres_virtual = params.width;
	info->var.yres_virtual = params.height;
	info->var.bits_per_pixel = params.format->bits_per_pixel;
	info->var.red = params.format->red;
	info->var.green = params.format->green;
	info->var.blue = params.format->blue;
	info->var.transp = params.format->transp;

	info->apertures = alloc_apertures(1);
	if (!info->apertures) {
		ret = -ENOMEM;
		goto error_fb_release;
	}
	info->apertures->ranges[0].base = info->fix.smem_start;
	info->apertures->ranges[0].size = info->fix.smem_len;

	info->fbops = &simplefb_ops;
	info->flags = FBINFO_DEFAULT | FBINFO_MISC_FIRMWARE;
	info->screen_base = ioremap_wc(info->fix.smem_start,
				       info->fix.smem_len);
	if (!info->screen_base) {
		ret = -ENOMEM;
		goto error_fb_release;
	}
	info->pseudo_palette = par->palette;

	ret = simplefb_clocks_init(par, pdev);
	if (ret < 0)
		goto error_unmap;

	ret = simplefb_regulators_init(par, pdev);
	if (ret < 0)
		goto error_clocks;

	dev_info(&pdev->dev, "framebuffer at 0x%lx, 0x%x bytes, mapped to 0x%p\n",
			     info->fix.smem_start, info->fix.smem_len,
			     info->screen_base);
	dev_info(&pdev->dev, "format=%s, mode=%dx%dx%d, linelength=%d\n",
			     params.format->name,
			     info->var.xres, info->var.yres,
			     info->var.bits_per_pixel, info->fix.line_length);

	ret = register_framebuffer(info);
	if (ret < 0) {
		dev_err(&pdev->dev, "Unable to register simplefb: %d\n", ret);
		goto error_regulators;
	}

	dev_info(&pdev->dev, "fb%d: simplefb registered!\n", info->node);

	return 0;

error_regulators:
	simplefb_regulators_destroy(par);
error_clocks:
	simplefb_clocks_destroy(par);
error_unmap:
	iounmap(info->screen_base);
error_fb_release:
	framebuffer_release(info);
	return ret;
}

static int simplefb_remove(struct platform_device *pdev)
{
	struct fb_info *info = platform_get_drvdata(pdev);

	unregister_framebuffer(info);
	framebuffer_release(info);

	return 0;
}

static const struct of_device_id simplefb_of_match[] = {
	{ .compatible = "simple-framebuffer", },
	{ },
};
MODULE_DEVICE_TABLE(of, simplefb_of_match);

static struct platform_driver simplefb_driver = {
	.driver = {
		.name = "simple-framebuffer",
		.of_match_table = simplefb_of_match,
	},
	.probe = simplefb_probe,
	.remove = simplefb_remove,
};

static int __init simplefb_init(void)
{
	int ret;
	struct device_node *np;

	ret = platform_driver_register(&simplefb_driver);
	if (ret)
		return ret;

	if (IS_ENABLED(CONFIG_OF_ADDRESS) && of_chosen) {
		for_each_child_of_node(of_chosen, np) {
			if (of_device_is_compatible(np, "simple-framebuffer"))
				of_platform_device_create(np, NULL, NULL);
		}
	}

	return 0;
}

fs_initcall(simplefb_init);

MODULE_AUTHOR("Stephen Warren <swarren@wwwdotorg.org>");
MODULE_DESCRIPTION("Simple framebuffer driver");
MODULE_LICENSE("GPL v2");