xref: /linux/drivers/gpu/drm/sysfb/simpledrm.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/aperture.h>
4 #include <linux/clk.h>
5 #include <linux/of_clk.h>
6 #include <linux/minmax.h>
7 #include <linux/of_reserved_mem.h>
8 #include <linux/platform_data/simplefb.h>
9 #include <linux/platform_device.h>
10 #include <linux/pm_domain.h>
11 #include <linux/regulator/consumer.h>
12 
13 #include <drm/clients/drm_client_setup.h>
14 #include <drm/drm_atomic.h>
15 #include <drm/drm_atomic_state_helper.h>
16 #include <drm/drm_connector.h>
17 #include <drm/drm_damage_helper.h>
18 #include <drm/drm_device.h>
19 #include <drm/drm_drv.h>
20 #include <drm/drm_fbdev_shmem.h>
21 #include <drm/drm_framebuffer.h>
22 #include <drm/drm_gem_atomic_helper.h>
23 #include <drm/drm_gem_framebuffer_helper.h>
24 #include <drm/drm_gem_shmem_helper.h>
25 #include <drm/drm_managed.h>
26 #include <drm/drm_modeset_helper_vtables.h>
27 #include <drm/drm_probe_helper.h>
28 
29 #include "drm_sysfb_helper.h"
30 
31 #define DRIVER_NAME	"simpledrm"
32 #define DRIVER_DESC	"DRM driver for simple-framebuffer platform devices"
33 #define DRIVER_MAJOR	1
34 #define DRIVER_MINOR	0
35 
36 /*
37  * Helpers for simplefb
38  */
39 
40 static int
41 simplefb_get_validated_int(struct drm_device *dev, const char *name,
42 			   uint32_t value)
43 {
44 	return drm_sysfb_get_validated_int(dev, name, value, INT_MAX);
45 }
46 
47 static int
48 simplefb_get_validated_int0(struct drm_device *dev, const char *name,
49 			    uint32_t value)
50 {
51 	return drm_sysfb_get_validated_int0(dev, name, value, INT_MAX);
52 }
53 
54 static const struct drm_format_info *
55 simplefb_get_validated_format(struct drm_device *dev, const char *format_name)
56 {
57 	static const struct simplefb_format formats[] = SIMPLEFB_FORMATS;
58 	const struct simplefb_format *fmt = formats;
59 	const struct simplefb_format *end = fmt + ARRAY_SIZE(formats);
60 	const struct drm_format_info *info;
61 
62 	if (!format_name) {
63 		drm_err(dev, "simplefb: missing framebuffer format\n");
64 		return ERR_PTR(-EINVAL);
65 	}
66 
67 	while (fmt < end) {
68 		if (!strcmp(format_name, fmt->name)) {
69 			info = drm_format_info(fmt->fourcc);
70 			if (!info)
71 				return ERR_PTR(-EINVAL);
72 			return info;
73 		}
74 		++fmt;
75 	}
76 
77 	drm_err(dev, "simplefb: unknown framebuffer format %s\n",
78 		format_name);
79 
80 	return ERR_PTR(-EINVAL);
81 }
82 
83 static int
84 simplefb_get_width_pd(struct drm_device *dev,
85 		      const struct simplefb_platform_data *pd)
86 {
87 	return simplefb_get_validated_int0(dev, "width", pd->width);
88 }
89 
90 static int
91 simplefb_get_height_pd(struct drm_device *dev,
92 		       const struct simplefb_platform_data *pd)
93 {
94 	return simplefb_get_validated_int0(dev, "height", pd->height);
95 }
96 
97 static int
98 simplefb_get_stride_pd(struct drm_device *dev,
99 		       const struct simplefb_platform_data *pd)
100 {
101 	return simplefb_get_validated_int(dev, "stride", pd->stride);
102 }
103 
104 static const struct drm_format_info *
105 simplefb_get_format_pd(struct drm_device *dev,
106 		       const struct simplefb_platform_data *pd)
107 {
108 	return simplefb_get_validated_format(dev, pd->format);
109 }
110 
111 static int
112 simplefb_read_u32_of(struct drm_device *dev, struct device_node *of_node,
113 		     const char *name, u32 *value)
114 {
115 	int ret = of_property_read_u32(of_node, name, value);
116 
117 	if (ret)
118 		drm_err(dev, "simplefb: cannot parse framebuffer %s: error %d\n",
119 			name, ret);
120 	return ret;
121 }
122 
123 static int
124 simplefb_read_string_of(struct drm_device *dev, struct device_node *of_node,
125 			const char *name, const char **value)
126 {
127 	int ret = of_property_read_string(of_node, name, value);
128 
129 	if (ret)
130 		drm_err(dev, "simplefb: cannot parse framebuffer %s: error %d\n",
131 			name, ret);
132 	return ret;
133 }
134 
135 static int
136 simplefb_get_width_of(struct drm_device *dev, struct device_node *of_node)
137 {
138 	u32 width;
139 	int ret = simplefb_read_u32_of(dev, of_node, "width", &width);
140 
141 	if (ret)
142 		return ret;
143 	return simplefb_get_validated_int0(dev, "width", width);
144 }
145 
146 static int
147 simplefb_get_height_of(struct drm_device *dev, struct device_node *of_node)
148 {
149 	u32 height;
150 	int ret = simplefb_read_u32_of(dev, of_node, "height", &height);
151 
152 	if (ret)
153 		return ret;
154 	return simplefb_get_validated_int0(dev, "height", height);
155 }
156 
157 static int
158 simplefb_get_stride_of(struct drm_device *dev, struct device_node *of_node)
159 {
160 	u32 stride;
161 	int ret = simplefb_read_u32_of(dev, of_node, "stride", &stride);
162 
163 	if (ret)
164 		return ret;
165 	return simplefb_get_validated_int(dev, "stride", stride);
166 }
167 
168 static const struct drm_format_info *
169 simplefb_get_format_of(struct drm_device *dev, struct device_node *of_node)
170 {
171 	const char *format;
172 	int ret = simplefb_read_string_of(dev, of_node, "format", &format);
173 
174 	if (ret)
175 		return ERR_PTR(ret);
176 	return simplefb_get_validated_format(dev, format);
177 }
178 
179 static struct resource *
180 simplefb_get_memory_of(struct drm_device *dev, struct device_node *of_node)
181 {
182 	struct resource r, *res;
183 	int err;
184 
185 	err = of_reserved_mem_region_to_resource(of_node, 0, &r);
186 	if (err)
187 		return NULL;
188 
189 	res = devm_kmemdup(dev->dev, &r, sizeof(r), GFP_KERNEL);
190 	if (!res)
191 		return ERR_PTR(-ENOMEM);
192 
193 	if (of_property_present(of_node, "reg"))
194 		drm_warn(dev, "preferring \"memory-region\" over \"reg\" property\n");
195 
196 	return res;
197 }
198 
199 /*
200  * Simple Framebuffer device
201  */
202 
203 struct simpledrm_device {
204 	struct drm_sysfb_device sysfb;
205 
206 	/* clocks */
207 #if defined CONFIG_OF && defined CONFIG_COMMON_CLK
208 	unsigned int clk_count;
209 	struct clk **clks;
210 #endif
211 	/* regulators */
212 #if defined CONFIG_OF && defined CONFIG_REGULATOR
213 	unsigned int regulator_count;
214 	struct regulator **regulators;
215 #endif
216 	/* power-domains */
217 #if defined CONFIG_OF && defined CONFIG_PM_GENERIC_DOMAINS
218 	int pwr_dom_count;
219 	struct device **pwr_dom_devs;
220 	struct device_link **pwr_dom_links;
221 #endif
222 
223 	/* modesetting */
224 	u32 formats[DRM_SYSFB_PLANE_NFORMATS(1)];
225 	struct drm_plane primary_plane;
226 	struct drm_crtc crtc;
227 	struct drm_encoder encoder;
228 	struct drm_connector connector;
229 };
230 
231 /*
232  * Hardware
233  */
234 
235 #if defined CONFIG_OF && defined CONFIG_COMMON_CLK
236 /*
237  * Clock handling code.
238  *
239  * Here we handle the clocks property of our "simple-framebuffer" dt node.
240  * This is necessary so that we can make sure that any clocks needed by
241  * the display engine that the bootloader set up for us (and for which it
242  * provided a simplefb dt node), stay up, for the life of the simplefb
243  * driver.
244  *
245  * When the driver unloads, we cleanly disable, and then release the clocks.
246  *
247  * We only complain about errors here, no action is taken as the most likely
248  * error can only happen due to a mismatch between the bootloader which set
249  * up simplefb, and the clock definitions in the device tree. Chances are
250  * that there are no adverse effects, and if there are, a clean teardown of
251  * the fb probe will not help us much either. So just complain and carry on,
252  * and hope that the user actually gets a working fb at the end of things.
253  */
254 
255 static void simpledrm_device_release_clocks(void *res)
256 {
257 	struct simpledrm_device *sdev = res;
258 	unsigned int i;
259 
260 	for (i = 0; i < sdev->clk_count; ++i) {
261 		if (sdev->clks[i]) {
262 			clk_disable_unprepare(sdev->clks[i]);
263 			clk_put(sdev->clks[i]);
264 		}
265 	}
266 }
267 
268 static int simpledrm_device_init_clocks(struct simpledrm_device *sdev)
269 {
270 	struct drm_device *dev = &sdev->sysfb.dev;
271 	struct platform_device *pdev = to_platform_device(dev->dev);
272 	struct device_node *of_node = pdev->dev.of_node;
273 	struct clk *clock;
274 	unsigned int i;
275 	int ret;
276 
277 	if (dev_get_platdata(&pdev->dev) || !of_node)
278 		return 0;
279 
280 	sdev->clk_count = of_clk_get_parent_count(of_node);
281 	if (!sdev->clk_count)
282 		return 0;
283 
284 	sdev->clks = drmm_kzalloc(dev, sdev->clk_count * sizeof(sdev->clks[0]),
285 				  GFP_KERNEL);
286 	if (!sdev->clks)
287 		return -ENOMEM;
288 
289 	for (i = 0; i < sdev->clk_count; ++i) {
290 		clock = of_clk_get(of_node, i);
291 		if (IS_ERR(clock)) {
292 			ret = PTR_ERR(clock);
293 			if (ret == -EPROBE_DEFER)
294 				goto err;
295 			drm_err(dev, "clock %u not found: %d\n", i, ret);
296 			continue;
297 		}
298 		ret = clk_prepare_enable(clock);
299 		if (ret) {
300 			drm_err(dev, "failed to enable clock %u: %d\n",
301 				i, ret);
302 			clk_put(clock);
303 			continue;
304 		}
305 		sdev->clks[i] = clock;
306 	}
307 
308 	return devm_add_action_or_reset(&pdev->dev,
309 					simpledrm_device_release_clocks,
310 					sdev);
311 
312 err:
313 	while (i) {
314 		--i;
315 		if (sdev->clks[i]) {
316 			clk_disable_unprepare(sdev->clks[i]);
317 			clk_put(sdev->clks[i]);
318 		}
319 	}
320 	return ret;
321 }
322 #else
323 static int simpledrm_device_init_clocks(struct simpledrm_device *sdev)
324 {
325 	return 0;
326 }
327 #endif
328 
329 #if defined CONFIG_OF && defined CONFIG_REGULATOR
330 
331 #define SUPPLY_SUFFIX "-supply"
332 
333 /*
334  * Regulator handling code.
335  *
336  * Here we handle the num-supplies and vin*-supply properties of our
337  * "simple-framebuffer" dt node. This is necessary so that we can make sure
338  * that any regulators needed by the display hardware that the bootloader
339  * set up for us (and for which it provided a simplefb dt node), stay up,
340  * for the life of the simplefb driver.
341  *
342  * When the driver unloads, we cleanly disable, and then release the
343  * regulators.
344  *
345  * We only complain about errors here, no action is taken as the most likely
346  * error can only happen due to a mismatch between the bootloader which set
347  * up simplefb, and the regulator definitions in the device tree. Chances are
348  * that there are no adverse effects, and if there are, a clean teardown of
349  * the fb probe will not help us much either. So just complain and carry on,
350  * and hope that the user actually gets a working fb at the end of things.
351  */
352 
353 static void simpledrm_device_release_regulators(void *res)
354 {
355 	struct simpledrm_device *sdev = res;
356 	unsigned int i;
357 
358 	for (i = 0; i < sdev->regulator_count; ++i) {
359 		if (sdev->regulators[i]) {
360 			regulator_disable(sdev->regulators[i]);
361 			regulator_put(sdev->regulators[i]);
362 		}
363 	}
364 }
365 
366 static int simpledrm_device_init_regulators(struct simpledrm_device *sdev)
367 {
368 	struct drm_device *dev = &sdev->sysfb.dev;
369 	struct platform_device *pdev = to_platform_device(dev->dev);
370 	struct device_node *of_node = pdev->dev.of_node;
371 	struct property *prop;
372 	struct regulator *regulator;
373 	const char *p;
374 	unsigned int count = 0, i = 0;
375 	int ret;
376 
377 	if (dev_get_platdata(&pdev->dev) || !of_node)
378 		return 0;
379 
380 	/* Count the number of regulator supplies */
381 	for_each_property_of_node(of_node, prop) {
382 		p = strstr(prop->name, SUPPLY_SUFFIX);
383 		if (p && p != prop->name)
384 			++count;
385 	}
386 
387 	if (!count)
388 		return 0;
389 
390 	sdev->regulators = drmm_kzalloc(dev,
391 					count * sizeof(sdev->regulators[0]),
392 					GFP_KERNEL);
393 	if (!sdev->regulators)
394 		return -ENOMEM;
395 
396 	for_each_property_of_node(of_node, prop) {
397 		char name[32]; /* 32 is max size of property name */
398 		size_t len;
399 
400 		p = strstr(prop->name, SUPPLY_SUFFIX);
401 		if (!p || p == prop->name)
402 			continue;
403 		len = strlen(prop->name) - strlen(SUPPLY_SUFFIX) + 1;
404 		strscpy(name, prop->name, min(sizeof(name), len));
405 
406 		regulator = regulator_get_optional(&pdev->dev, name);
407 		if (IS_ERR(regulator)) {
408 			ret = PTR_ERR(regulator);
409 			if (ret == -EPROBE_DEFER)
410 				goto err;
411 			drm_err(dev, "regulator %s not found: %d\n",
412 				name, ret);
413 			continue;
414 		}
415 
416 		ret = regulator_enable(regulator);
417 		if (ret) {
418 			drm_err(dev, "failed to enable regulator %u: %d\n",
419 				i, ret);
420 			regulator_put(regulator);
421 			continue;
422 		}
423 
424 		sdev->regulators[i++] = regulator;
425 	}
426 	sdev->regulator_count = i;
427 
428 	return devm_add_action_or_reset(&pdev->dev,
429 					simpledrm_device_release_regulators,
430 					sdev);
431 
432 err:
433 	while (i) {
434 		--i;
435 		if (sdev->regulators[i]) {
436 			regulator_disable(sdev->regulators[i]);
437 			regulator_put(sdev->regulators[i]);
438 		}
439 	}
440 	return ret;
441 }
442 #else
443 static int simpledrm_device_init_regulators(struct simpledrm_device *sdev)
444 {
445 	return 0;
446 }
447 #endif
448 
449 #if defined CONFIG_OF && defined CONFIG_PM_GENERIC_DOMAINS
450 /*
451  * Generic power domain handling code.
452  *
453  * Here we handle the power-domains properties of our "simple-framebuffer"
454  * dt node. This is only necessary if there is more than one power-domain.
455  * A single power-domains is handled automatically by the driver core. Multiple
456  * power-domains have to be handled by drivers since the driver core can't know
457  * the correct power sequencing. Power sequencing is not an issue for simpledrm
458  * since the bootloader has put the power domains already in the correct state.
459  * simpledrm has only to ensure they remain active for its lifetime.
460  *
461  * When the driver unloads, we detach from the power-domains.
462  *
463  * We only complain about errors here, no action is taken as the most likely
464  * error can only happen due to a mismatch between the bootloader which set
465  * up the "simple-framebuffer" dt node, and the PM domain providers in the
466  * device tree. Chances are that there are no adverse effects, and if there are,
467  * a clean teardown of the fb probe will not help us much either. So just
468  * complain and carry on, and hope that the user actually gets a working fb at
469  * the end of things.
470  */
471 static void simpledrm_device_detach_genpd(void *res)
472 {
473 	int i;
474 	struct simpledrm_device *sdev = res;
475 
476 	if (sdev->pwr_dom_count <= 1)
477 		return;
478 
479 	for (i = sdev->pwr_dom_count - 1; i >= 0; i--) {
480 		if (sdev->pwr_dom_links[i])
481 			device_link_del(sdev->pwr_dom_links[i]);
482 		if (!IS_ERR_OR_NULL(sdev->pwr_dom_devs[i]))
483 			dev_pm_domain_detach(sdev->pwr_dom_devs[i], true);
484 	}
485 }
486 
487 static int simpledrm_device_attach_genpd(struct simpledrm_device *sdev)
488 {
489 	struct device *dev = sdev->sysfb.dev.dev;
490 	int i;
491 
492 	sdev->pwr_dom_count = of_count_phandle_with_args(dev->of_node, "power-domains",
493 							 "#power-domain-cells");
494 	/*
495 	 * Single power-domain devices are handled by driver core nothing to do
496 	 * here. The same for device nodes without "power-domains" property.
497 	 */
498 	if (sdev->pwr_dom_count <= 1)
499 		return 0;
500 
501 	sdev->pwr_dom_devs = devm_kcalloc(dev, sdev->pwr_dom_count,
502 					       sizeof(*sdev->pwr_dom_devs),
503 					       GFP_KERNEL);
504 	if (!sdev->pwr_dom_devs)
505 		return -ENOMEM;
506 
507 	sdev->pwr_dom_links = devm_kcalloc(dev, sdev->pwr_dom_count,
508 						sizeof(*sdev->pwr_dom_links),
509 						GFP_KERNEL);
510 	if (!sdev->pwr_dom_links)
511 		return -ENOMEM;
512 
513 	for (i = 0; i < sdev->pwr_dom_count; i++) {
514 		sdev->pwr_dom_devs[i] = dev_pm_domain_attach_by_id(dev, i);
515 		if (IS_ERR(sdev->pwr_dom_devs[i])) {
516 			int ret = PTR_ERR(sdev->pwr_dom_devs[i]);
517 			if (ret == -EPROBE_DEFER) {
518 				simpledrm_device_detach_genpd(sdev);
519 				return ret;
520 			}
521 			drm_warn(&sdev->sysfb.dev,
522 				 "pm_domain_attach_by_id(%u) failed: %d\n", i, ret);
523 			continue;
524 		}
525 
526 		sdev->pwr_dom_links[i] = device_link_add(dev,
527 							 sdev->pwr_dom_devs[i],
528 							 DL_FLAG_STATELESS |
529 							 DL_FLAG_PM_RUNTIME |
530 							 DL_FLAG_RPM_ACTIVE);
531 		if (!sdev->pwr_dom_links[i])
532 			drm_warn(&sdev->sysfb.dev, "failed to link power-domain %d\n", i);
533 	}
534 
535 	return devm_add_action_or_reset(dev, simpledrm_device_detach_genpd, sdev);
536 }
537 #else
538 static int simpledrm_device_attach_genpd(struct simpledrm_device *sdev)
539 {
540 	return 0;
541 }
542 #endif
543 
544 /*
545  * Modesetting
546  */
547 
548 static const u64 simpledrm_primary_plane_format_modifiers[] = {
549 	DRM_SYSFB_PLANE_FORMAT_MODIFIERS,
550 };
551 
552 static const struct drm_plane_helper_funcs simpledrm_primary_plane_helper_funcs = {
553 	DRM_SYSFB_PLANE_HELPER_FUNCS,
554 };
555 
556 static const struct drm_plane_funcs simpledrm_primary_plane_funcs = {
557 	DRM_SYSFB_PLANE_FUNCS,
558 	.destroy = drm_plane_cleanup,
559 };
560 
561 static const struct drm_crtc_helper_funcs simpledrm_crtc_helper_funcs = {
562 	DRM_SYSFB_CRTC_HELPER_FUNCS,
563 };
564 
565 static const struct drm_crtc_funcs simpledrm_crtc_funcs = {
566 	DRM_SYSFB_CRTC_FUNCS,
567 	.destroy = drm_crtc_cleanup,
568 };
569 
570 static const struct drm_encoder_funcs simpledrm_encoder_funcs = {
571 	.destroy = drm_encoder_cleanup,
572 };
573 
574 static const struct drm_connector_helper_funcs simpledrm_connector_helper_funcs = {
575 	DRM_SYSFB_CONNECTOR_HELPER_FUNCS,
576 };
577 
578 static const struct drm_connector_funcs simpledrm_connector_funcs = {
579 	DRM_SYSFB_CONNECTOR_FUNCS,
580 	.destroy = drm_connector_cleanup,
581 };
582 
583 static const struct drm_mode_config_funcs simpledrm_mode_config_funcs = {
584 	DRM_SYSFB_MODE_CONFIG_FUNCS,
585 };
586 
587 /*
588  * Init / Cleanup
589  */
590 
591 static struct simpledrm_device *simpledrm_device_create(struct drm_driver *drv,
592 							struct platform_device *pdev)
593 {
594 	const struct simplefb_platform_data *pd = dev_get_platdata(&pdev->dev);
595 	struct device_node *of_node = pdev->dev.of_node;
596 	struct simpledrm_device *sdev;
597 	struct drm_sysfb_device *sysfb;
598 	struct drm_device *dev;
599 	int width, height, stride;
600 	int width_mm = 0, height_mm = 0;
601 	struct device_node *panel_node;
602 	const struct drm_format_info *format;
603 	struct resource *res, *mem = NULL;
604 	struct drm_plane *primary_plane;
605 	struct drm_crtc *crtc;
606 	struct drm_encoder *encoder;
607 	struct drm_connector *connector;
608 	unsigned long max_width, max_height;
609 	size_t nformats;
610 	int ret;
611 
612 	sdev = devm_drm_dev_alloc(&pdev->dev, drv, struct simpledrm_device, sysfb.dev);
613 	if (IS_ERR(sdev))
614 		return ERR_CAST(sdev);
615 	sysfb = &sdev->sysfb;
616 	dev = &sysfb->dev;
617 	platform_set_drvdata(pdev, sdev);
618 
619 	/*
620 	 * Hardware settings
621 	 */
622 
623 	ret = simpledrm_device_init_clocks(sdev);
624 	if (ret)
625 		return ERR_PTR(ret);
626 	ret = simpledrm_device_init_regulators(sdev);
627 	if (ret)
628 		return ERR_PTR(ret);
629 	ret = simpledrm_device_attach_genpd(sdev);
630 	if (ret)
631 		return ERR_PTR(ret);
632 
633 	if (pd) {
634 		width = simplefb_get_width_pd(dev, pd);
635 		if (width < 0)
636 			return ERR_PTR(width);
637 		height = simplefb_get_height_pd(dev, pd);
638 		if (height < 0)
639 			return ERR_PTR(height);
640 		stride = simplefb_get_stride_pd(dev, pd);
641 		if (stride < 0)
642 			return ERR_PTR(stride);
643 		format = simplefb_get_format_pd(dev, pd);
644 		if (IS_ERR(format))
645 			return ERR_CAST(format);
646 	} else if (of_node) {
647 		width = simplefb_get_width_of(dev, of_node);
648 		if (width < 0)
649 			return ERR_PTR(width);
650 		height = simplefb_get_height_of(dev, of_node);
651 		if (height < 0)
652 			return ERR_PTR(height);
653 		stride = simplefb_get_stride_of(dev, of_node);
654 		if (stride < 0)
655 			return ERR_PTR(stride);
656 		format = simplefb_get_format_of(dev, of_node);
657 		if (IS_ERR(format))
658 			return ERR_CAST(format);
659 		mem = simplefb_get_memory_of(dev, of_node);
660 		if (IS_ERR(mem))
661 			return ERR_CAST(mem);
662 		panel_node = of_parse_phandle(of_node, "panel", 0);
663 		if (panel_node) {
664 			simplefb_read_u32_of(dev, panel_node, "width-mm", &width_mm);
665 			simplefb_read_u32_of(dev, panel_node, "height-mm", &height_mm);
666 			of_node_put(panel_node);
667 		}
668 	} else {
669 		drm_err(dev, "no simplefb configuration found\n");
670 		return ERR_PTR(-ENODEV);
671 	}
672 	if (!stride) {
673 		stride = drm_format_info_min_pitch(format, 0, width);
674 		if (drm_WARN_ON(dev, !stride))
675 			return ERR_PTR(-EINVAL);
676 	}
677 
678 	sysfb->fb_mode = drm_sysfb_mode(width, height, width_mm, height_mm);
679 	sysfb->fb_format = format;
680 	sysfb->fb_pitch = stride;
681 
682 	drm_dbg(dev, "display mode={" DRM_MODE_FMT "}\n", DRM_MODE_ARG(&sysfb->fb_mode));
683 	drm_dbg(dev, "framebuffer format=%p4cc, size=%dx%d, stride=%d byte\n",
684 		&format->format, width, height, stride);
685 
686 	/*
687 	 * Memory management
688 	 */
689 
690 	if (mem) {
691 		void *screen_base;
692 
693 		ret = devm_aperture_acquire_for_platform_device(pdev, mem->start,
694 								resource_size(mem));
695 		if (ret) {
696 			drm_err(dev, "could not acquire memory range %pr: %d\n", mem, ret);
697 			return ERR_PTR(ret);
698 		}
699 
700 		drm_dbg(dev, "using system memory framebuffer at %pr\n", mem);
701 
702 		screen_base = devm_memremap(dev->dev, mem->start, resource_size(mem), MEMREMAP_WC);
703 		if (IS_ERR(screen_base))
704 			return screen_base;
705 
706 		iosys_map_set_vaddr(&sysfb->fb_addr, screen_base);
707 	} else {
708 		void __iomem *screen_base;
709 
710 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
711 		if (!res)
712 			return ERR_PTR(-EINVAL);
713 
714 		ret = devm_aperture_acquire_for_platform_device(pdev, res->start,
715 								resource_size(res));
716 		if (ret) {
717 			drm_err(dev, "could not acquire memory range %pr: %d\n", res, ret);
718 			return ERR_PTR(ret);
719 		}
720 
721 		drm_dbg(dev, "using I/O memory framebuffer at %pr\n", res);
722 
723 		mem = devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
724 					      drv->name);
725 		if (!mem) {
726 			/*
727 			 * We cannot make this fatal. Sometimes this comes from magic
728 			 * spaces our resource handlers simply don't know about. Use
729 			 * the I/O-memory resource as-is and try to map that instead.
730 			 */
731 			drm_warn(dev, "could not acquire memory region %pr\n", res);
732 			mem = res;
733 		}
734 
735 		screen_base = devm_ioremap_wc(&pdev->dev, mem->start, resource_size(mem));
736 		if (!screen_base)
737 			return ERR_PTR(-ENOMEM);
738 
739 		iosys_map_set_vaddr_iomem(&sysfb->fb_addr, screen_base);
740 	}
741 
742 	/*
743 	 * Modesetting
744 	 */
745 
746 	ret = drmm_mode_config_init(dev);
747 	if (ret)
748 		return ERR_PTR(ret);
749 
750 	max_width = max_t(unsigned long, width, DRM_SHADOW_PLANE_MAX_WIDTH);
751 	max_height = max_t(unsigned long, height, DRM_SHADOW_PLANE_MAX_HEIGHT);
752 
753 	dev->mode_config.min_width = width;
754 	dev->mode_config.max_width = max_width;
755 	dev->mode_config.min_height = height;
756 	dev->mode_config.max_height = max_height;
757 	dev->mode_config.preferred_depth = format->depth;
758 	dev->mode_config.funcs = &simpledrm_mode_config_funcs;
759 
760 	/* Primary plane */
761 
762 	nformats = drm_sysfb_build_fourcc_list(dev, &format->format, 1,
763 					       sdev->formats, ARRAY_SIZE(sdev->formats));
764 
765 	primary_plane = &sdev->primary_plane;
766 	ret = drm_universal_plane_init(dev, primary_plane, 0, &simpledrm_primary_plane_funcs,
767 				       sdev->formats, nformats,
768 				       simpledrm_primary_plane_format_modifiers,
769 				       DRM_PLANE_TYPE_PRIMARY, NULL);
770 	if (ret)
771 		return ERR_PTR(ret);
772 	drm_plane_helper_add(primary_plane, &simpledrm_primary_plane_helper_funcs);
773 	drm_plane_enable_fb_damage_clips(primary_plane);
774 
775 	/* CRTC */
776 
777 	crtc = &sdev->crtc;
778 	ret = drm_crtc_init_with_planes(dev, crtc, primary_plane, NULL,
779 					&simpledrm_crtc_funcs, NULL);
780 	if (ret)
781 		return ERR_PTR(ret);
782 	drm_crtc_helper_add(crtc, &simpledrm_crtc_helper_funcs);
783 
784 	/* Encoder */
785 
786 	encoder = &sdev->encoder;
787 	ret = drm_encoder_init(dev, encoder, &simpledrm_encoder_funcs,
788 			       DRM_MODE_ENCODER_NONE, NULL);
789 	if (ret)
790 		return ERR_PTR(ret);
791 	encoder->possible_crtcs = drm_crtc_mask(crtc);
792 
793 	/* Connector */
794 
795 	connector = &sdev->connector;
796 	ret = drm_connector_init(dev, connector, &simpledrm_connector_funcs,
797 				 DRM_MODE_CONNECTOR_Unknown);
798 	if (ret)
799 		return ERR_PTR(ret);
800 	drm_connector_helper_add(connector, &simpledrm_connector_helper_funcs);
801 	drm_connector_set_panel_orientation_with_quirk(connector,
802 						       DRM_MODE_PANEL_ORIENTATION_UNKNOWN,
803 						       width, height);
804 
805 	ret = drm_connector_attach_encoder(connector, encoder);
806 	if (ret)
807 		return ERR_PTR(ret);
808 
809 	drm_mode_config_reset(dev);
810 
811 	return sdev;
812 }
813 
814 /*
815  * DRM driver
816  */
817 
818 DEFINE_DRM_GEM_FOPS(simpledrm_fops);
819 
820 static struct drm_driver simpledrm_driver = {
821 	DRM_GEM_SHMEM_DRIVER_OPS,
822 	DRM_FBDEV_SHMEM_DRIVER_OPS,
823 	.name			= DRIVER_NAME,
824 	.desc			= DRIVER_DESC,
825 	.major			= DRIVER_MAJOR,
826 	.minor			= DRIVER_MINOR,
827 	.driver_features	= DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
828 	.fops			= &simpledrm_fops,
829 };
830 
831 /*
832  * Platform driver
833  */
834 
835 static int simpledrm_probe(struct platform_device *pdev)
836 {
837 	struct simpledrm_device *sdev;
838 	struct drm_sysfb_device *sysfb;
839 	struct drm_device *dev;
840 	int ret;
841 
842 	sdev = simpledrm_device_create(&simpledrm_driver, pdev);
843 	if (IS_ERR(sdev))
844 		return PTR_ERR(sdev);
845 	sysfb = &sdev->sysfb;
846 	dev = &sysfb->dev;
847 
848 	ret = drm_dev_register(dev, 0);
849 	if (ret)
850 		return ret;
851 
852 	drm_client_setup(dev, sdev->sysfb.fb_format);
853 
854 	return 0;
855 }
856 
857 static void simpledrm_remove(struct platform_device *pdev)
858 {
859 	struct simpledrm_device *sdev = platform_get_drvdata(pdev);
860 	struct drm_device *dev = &sdev->sysfb.dev;
861 
862 	drm_dev_unplug(dev);
863 }
864 
865 static const struct of_device_id simpledrm_of_match_table[] = {
866 	{ .compatible = "simple-framebuffer", },
867 	{ },
868 };
869 MODULE_DEVICE_TABLE(of, simpledrm_of_match_table);
870 
871 static struct platform_driver simpledrm_platform_driver = {
872 	.driver = {
873 		.name = "simple-framebuffer", /* connect to sysfb */
874 		.of_match_table = simpledrm_of_match_table,
875 	},
876 	.probe = simpledrm_probe,
877 	.remove = simpledrm_remove,
878 };
879 
880 module_platform_driver(simpledrm_platform_driver);
881 
882 MODULE_DESCRIPTION(DRIVER_DESC);
883 MODULE_LICENSE("GPL v2");
884