xref: /linux/drivers/gpu/drm/tiny/ofdrm.c (revision 6c7353836a91b1479e6b81791cdc163fb04b4834)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/of_address.h>
4 #include <linux/pci.h>
5 #include <linux/platform_device.h>
6 
7 #include <drm/drm_aperture.h>
8 #include <drm/drm_atomic.h>
9 #include <drm/drm_atomic_state_helper.h>
10 #include <drm/drm_connector.h>
11 #include <drm/drm_damage_helper.h>
12 #include <drm/drm_device.h>
13 #include <drm/drm_drv.h>
14 #include <drm/drm_fbdev_generic.h>
15 #include <drm/drm_format_helper.h>
16 #include <drm/drm_framebuffer.h>
17 #include <drm/drm_gem_atomic_helper.h>
18 #include <drm/drm_gem_framebuffer_helper.h>
19 #include <drm/drm_gem_shmem_helper.h>
20 #include <drm/drm_managed.h>
21 #include <drm/drm_modeset_helper_vtables.h>
22 #include <drm/drm_probe_helper.h>
23 #include <drm/drm_simple_kms_helper.h>
24 
25 #define DRIVER_NAME	"ofdrm"
26 #define DRIVER_DESC	"DRM driver for OF platform devices"
27 #define DRIVER_DATE	"20220501"
28 #define DRIVER_MAJOR	1
29 #define DRIVER_MINOR	0
30 
31 #define PCI_VENDOR_ID_ATI_R520	0x7100
32 #define PCI_VENDOR_ID_ATI_R600	0x9400
33 
34 #define OFDRM_GAMMA_LUT_SIZE	256
35 
36 /* Definitions used by the Avivo palette  */
37 #define AVIVO_DC_LUT_RW_SELECT                  0x6480
38 #define AVIVO_DC_LUT_RW_MODE                    0x6484
39 #define AVIVO_DC_LUT_RW_INDEX                   0x6488
40 #define AVIVO_DC_LUT_SEQ_COLOR                  0x648c
41 #define AVIVO_DC_LUT_PWL_DATA                   0x6490
42 #define AVIVO_DC_LUT_30_COLOR                   0x6494
43 #define AVIVO_DC_LUT_READ_PIPE_SELECT           0x6498
44 #define AVIVO_DC_LUT_WRITE_EN_MASK              0x649c
45 #define AVIVO_DC_LUT_AUTOFILL                   0x64a0
46 #define AVIVO_DC_LUTA_CONTROL                   0x64c0
47 #define AVIVO_DC_LUTA_BLACK_OFFSET_BLUE         0x64c4
48 #define AVIVO_DC_LUTA_BLACK_OFFSET_GREEN        0x64c8
49 #define AVIVO_DC_LUTA_BLACK_OFFSET_RED          0x64cc
50 #define AVIVO_DC_LUTA_WHITE_OFFSET_BLUE         0x64d0
51 #define AVIVO_DC_LUTA_WHITE_OFFSET_GREEN        0x64d4
52 #define AVIVO_DC_LUTA_WHITE_OFFSET_RED          0x64d8
53 #define AVIVO_DC_LUTB_CONTROL                   0x6cc0
54 #define AVIVO_DC_LUTB_BLACK_OFFSET_BLUE         0x6cc4
55 #define AVIVO_DC_LUTB_BLACK_OFFSET_GREEN        0x6cc8
56 #define AVIVO_DC_LUTB_BLACK_OFFSET_RED          0x6ccc
57 #define AVIVO_DC_LUTB_WHITE_OFFSET_BLUE         0x6cd0
58 #define AVIVO_DC_LUTB_WHITE_OFFSET_GREEN        0x6cd4
59 #define AVIVO_DC_LUTB_WHITE_OFFSET_RED          0x6cd8
60 
61 enum ofdrm_model {
62 	OFDRM_MODEL_UNKNOWN,
63 	OFDRM_MODEL_MACH64, /* ATI Mach64 */
64 	OFDRM_MODEL_RAGE128, /* ATI Rage128 */
65 	OFDRM_MODEL_RAGE_M3A, /* ATI Rage Mobility M3 Head A */
66 	OFDRM_MODEL_RAGE_M3B, /* ATI Rage Mobility M3 Head B */
67 	OFDRM_MODEL_RADEON, /* ATI Radeon */
68 	OFDRM_MODEL_GXT2000, /* IBM GXT2000 */
69 	OFDRM_MODEL_AVIVO, /* ATI R5xx */
70 	OFDRM_MODEL_QEMU, /* QEMU VGA */
71 };
72 
73 /*
74  * Helpers for display nodes
75  */
76 
77 static int display_get_validated_int(struct drm_device *dev, const char *name, uint32_t value)
78 {
79 	if (value > INT_MAX) {
80 		drm_err(dev, "invalid framebuffer %s of %u\n", name, value);
81 		return -EINVAL;
82 	}
83 	return (int)value;
84 }
85 
86 static int display_get_validated_int0(struct drm_device *dev, const char *name, uint32_t value)
87 {
88 	if (!value) {
89 		drm_err(dev, "invalid framebuffer %s of %u\n", name, value);
90 		return -EINVAL;
91 	}
92 	return display_get_validated_int(dev, name, value);
93 }
94 
95 static const struct drm_format_info *display_get_validated_format(struct drm_device *dev,
96 								  u32 depth, bool big_endian)
97 {
98 	const struct drm_format_info *info;
99 	u32 format;
100 
101 	switch (depth) {
102 	case 8:
103 		format = drm_mode_legacy_fb_format(8, 8);
104 		break;
105 	case 15:
106 	case 16:
107 		format = drm_mode_legacy_fb_format(16, depth);
108 		break;
109 	case 32:
110 		format = drm_mode_legacy_fb_format(32, 24);
111 		break;
112 	default:
113 		drm_err(dev, "unsupported framebuffer depth %u\n", depth);
114 		return ERR_PTR(-EINVAL);
115 	}
116 
117 	/*
118 	 * DRM formats assume little-endian byte order. Update the format
119 	 * if the scanout buffer uses big-endian ordering.
120 	 */
121 	if (big_endian) {
122 		switch (format) {
123 		case DRM_FORMAT_XRGB8888:
124 			format = DRM_FORMAT_BGRX8888;
125 			break;
126 		case DRM_FORMAT_ARGB8888:
127 			format = DRM_FORMAT_BGRA8888;
128 			break;
129 		case DRM_FORMAT_RGB565:
130 			format = DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN;
131 			break;
132 		case DRM_FORMAT_XRGB1555:
133 			format = DRM_FORMAT_XRGB1555 | DRM_FORMAT_BIG_ENDIAN;
134 			break;
135 		default:
136 			break;
137 		}
138 	}
139 
140 	info = drm_format_info(format);
141 	if (!info) {
142 		drm_err(dev, "cannot find framebuffer format for depth %u\n", depth);
143 		return ERR_PTR(-EINVAL);
144 	}
145 
146 	return info;
147 }
148 
149 static int display_read_u32_of(struct drm_device *dev, struct device_node *of_node,
150 			       const char *name, u32 *value)
151 {
152 	int ret = of_property_read_u32(of_node, name, value);
153 
154 	if (ret)
155 		drm_err(dev, "cannot parse framebuffer %s: error %d\n", name, ret);
156 	return ret;
157 }
158 
159 static bool display_get_big_endian_of(struct drm_device *dev, struct device_node *of_node)
160 {
161 	bool big_endian;
162 
163 #ifdef __BIG_ENDIAN
164 	big_endian = !of_property_read_bool(of_node, "little-endian");
165 #else
166 	big_endian = of_property_read_bool(of_node, "big-endian");
167 #endif
168 
169 	return big_endian;
170 }
171 
172 static int display_get_width_of(struct drm_device *dev, struct device_node *of_node)
173 {
174 	u32 width;
175 	int ret = display_read_u32_of(dev, of_node, "width", &width);
176 
177 	if (ret)
178 		return ret;
179 	return display_get_validated_int0(dev, "width", width);
180 }
181 
182 static int display_get_height_of(struct drm_device *dev, struct device_node *of_node)
183 {
184 	u32 height;
185 	int ret = display_read_u32_of(dev, of_node, "height", &height);
186 
187 	if (ret)
188 		return ret;
189 	return display_get_validated_int0(dev, "height", height);
190 }
191 
192 static int display_get_depth_of(struct drm_device *dev, struct device_node *of_node)
193 {
194 	u32 depth;
195 	int ret = display_read_u32_of(dev, of_node, "depth", &depth);
196 
197 	if (ret)
198 		return ret;
199 	return display_get_validated_int0(dev, "depth", depth);
200 }
201 
202 static int display_get_linebytes_of(struct drm_device *dev, struct device_node *of_node)
203 {
204 	u32 linebytes;
205 	int ret = display_read_u32_of(dev, of_node, "linebytes", &linebytes);
206 
207 	if (ret)
208 		return ret;
209 	return display_get_validated_int(dev, "linebytes", linebytes);
210 }
211 
212 static u64 display_get_address_of(struct drm_device *dev, struct device_node *of_node)
213 {
214 	u32 address;
215 	int ret;
216 
217 	/*
218 	 * Not all devices provide an address property, it's not
219 	 * a bug if this fails. The driver will try to find the
220 	 * framebuffer base address from the device's memory regions.
221 	 */
222 	ret = of_property_read_u32(of_node, "address", &address);
223 	if (ret)
224 		return OF_BAD_ADDR;
225 
226 	return address;
227 }
228 
229 static bool is_avivo(u32 vendor, u32 device)
230 {
231 	/* This will match most R5xx */
232 	return (vendor == PCI_VENDOR_ID_ATI) &&
233 	       ((device >= PCI_VENDOR_ID_ATI_R520 && device < 0x7800) ||
234 		(PCI_VENDOR_ID_ATI_R600 >= 0x9400));
235 }
236 
237 static enum ofdrm_model display_get_model_of(struct drm_device *dev, struct device_node *of_node)
238 {
239 	enum ofdrm_model model = OFDRM_MODEL_UNKNOWN;
240 
241 	if (of_node_name_prefix(of_node, "ATY,Rage128")) {
242 		model = OFDRM_MODEL_RAGE128;
243 	} else if (of_node_name_prefix(of_node, "ATY,RageM3pA") ||
244 		   of_node_name_prefix(of_node, "ATY,RageM3p12A")) {
245 		model = OFDRM_MODEL_RAGE_M3A;
246 	} else if (of_node_name_prefix(of_node, "ATY,RageM3pB")) {
247 		model = OFDRM_MODEL_RAGE_M3B;
248 	} else if (of_node_name_prefix(of_node, "ATY,Rage6")) {
249 		model = OFDRM_MODEL_RADEON;
250 	} else if (of_node_name_prefix(of_node, "ATY,")) {
251 		return OFDRM_MODEL_MACH64;
252 	} else if (of_device_is_compatible(of_node, "pci1014,b7") ||
253 		   of_device_is_compatible(of_node, "pci1014,21c")) {
254 		model = OFDRM_MODEL_GXT2000;
255 	} else if (of_node_name_prefix(of_node, "vga,Display-")) {
256 		struct device_node *of_parent;
257 		const __be32 *vendor_p, *device_p;
258 
259 		/* Look for AVIVO initialized by SLOF */
260 		of_parent = of_get_parent(of_node);
261 		vendor_p = of_get_property(of_parent, "vendor-id", NULL);
262 		device_p = of_get_property(of_parent, "device-id", NULL);
263 		if (vendor_p && device_p) {
264 			u32 vendor = be32_to_cpup(vendor_p);
265 			u32 device = be32_to_cpup(device_p);
266 
267 			if (is_avivo(vendor, device))
268 				model = OFDRM_MODEL_AVIVO;
269 		}
270 		of_node_put(of_parent);
271 	} else if (of_device_is_compatible(of_node, "qemu,std-vga")) {
272 		model = OFDRM_MODEL_QEMU;
273 	}
274 
275 	return model;
276 }
277 
278 /*
279  * Open Firmware display device
280  */
281 
282 struct ofdrm_device;
283 
284 struct ofdrm_device_funcs {
285 	void __iomem *(*cmap_ioremap)(struct ofdrm_device *odev,
286 				      struct device_node *of_node,
287 				      u64 fb_bas);
288 	void (*cmap_write)(struct ofdrm_device *odev, unsigned char index,
289 			   unsigned char r, unsigned char g, unsigned char b);
290 };
291 
292 struct ofdrm_device {
293 	struct drm_device dev;
294 	struct platform_device *pdev;
295 
296 	const struct ofdrm_device_funcs *funcs;
297 
298 	/* firmware-buffer settings */
299 	struct iosys_map screen_base;
300 	struct drm_display_mode mode;
301 	const struct drm_format_info *format;
302 	unsigned int pitch;
303 
304 	/* colormap */
305 	void __iomem *cmap_base;
306 
307 	/* modesetting */
308 	uint32_t formats[8];
309 	struct drm_plane primary_plane;
310 	struct drm_crtc crtc;
311 	struct drm_encoder encoder;
312 	struct drm_connector connector;
313 };
314 
315 static struct ofdrm_device *ofdrm_device_of_dev(struct drm_device *dev)
316 {
317 	return container_of(dev, struct ofdrm_device, dev);
318 }
319 
320 /*
321  * Hardware
322  */
323 
324 #if defined(CONFIG_PCI)
325 static struct pci_dev *display_get_pci_dev_of(struct drm_device *dev, struct device_node *of_node)
326 {
327 	const __be32 *vendor_p, *device_p;
328 	u32 vendor, device;
329 	struct pci_dev *pcidev;
330 
331 	vendor_p = of_get_property(of_node, "vendor-id", NULL);
332 	if (!vendor_p)
333 		return ERR_PTR(-ENODEV);
334 	vendor = be32_to_cpup(vendor_p);
335 
336 	device_p = of_get_property(of_node, "device-id", NULL);
337 	if (!device_p)
338 		return ERR_PTR(-ENODEV);
339 	device = be32_to_cpup(device_p);
340 
341 	pcidev = pci_get_device(vendor, device, NULL);
342 	if (!pcidev)
343 		return ERR_PTR(-ENODEV);
344 
345 	return pcidev;
346 }
347 
348 static void ofdrm_pci_release(void *data)
349 {
350 	struct pci_dev *pcidev = data;
351 
352 	pci_disable_device(pcidev);
353 }
354 
355 static int ofdrm_device_init_pci(struct ofdrm_device *odev)
356 {
357 	struct drm_device *dev = &odev->dev;
358 	struct platform_device *pdev = to_platform_device(dev->dev);
359 	struct device_node *of_node = pdev->dev.of_node;
360 	struct pci_dev *pcidev;
361 	int ret;
362 
363 	/*
364 	 * Never use pcim_ or other managed helpers on the returned PCI
365 	 * device. Otherwise, probing the native driver will fail for
366 	 * resource conflicts. PCI-device management has to be tied to
367 	 * the lifetime of the platform device until the native driver
368 	 * takes over.
369 	 */
370 	pcidev = display_get_pci_dev_of(dev, of_node);
371 	if (IS_ERR(pcidev))
372 		return 0; /* no PCI device found; ignore the error */
373 
374 	ret = pci_enable_device(pcidev);
375 	if (ret) {
376 		drm_err(dev, "pci_enable_device(%s) failed: %d\n",
377 			dev_name(&pcidev->dev), ret);
378 		return ret;
379 	}
380 	ret = devm_add_action_or_reset(&pdev->dev, ofdrm_pci_release, pcidev);
381 	if (ret)
382 		return ret;
383 
384 	return 0;
385 }
386 #else
387 static int ofdrm_device_init_pci(struct ofdrm_device *odev)
388 {
389 	return 0;
390 }
391 #endif
392 
393 /*
394  *  OF display settings
395  */
396 
397 static struct resource *ofdrm_find_fb_resource(struct ofdrm_device *odev,
398 					       struct resource *fb_res)
399 {
400 	struct platform_device *pdev = to_platform_device(odev->dev.dev);
401 	struct resource *res, *max_res = NULL;
402 	u32 i;
403 
404 	for (i = 0; pdev->num_resources; ++i) {
405 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
406 		if (!res)
407 			break; /* all resources processed */
408 		if (resource_size(res) < resource_size(fb_res))
409 			continue; /* resource too small */
410 		if (fb_res->start && resource_contains(res, fb_res))
411 			return res; /* resource contains framebuffer */
412 		if (!max_res || resource_size(res) > resource_size(max_res))
413 			max_res = res; /* store largest resource as fallback */
414 	}
415 
416 	return max_res;
417 }
418 
419 /*
420  * Colormap / Palette
421  */
422 
423 static void __iomem *get_cmap_address_of(struct ofdrm_device *odev, struct device_node *of_node,
424 					 int bar_no, unsigned long offset, unsigned long size)
425 {
426 	struct drm_device *dev = &odev->dev;
427 	const __be32 *addr_p;
428 	u64 max_size, address;
429 	unsigned int flags;
430 	void __iomem *mem;
431 
432 	addr_p = of_get_pci_address(of_node, bar_no, &max_size, &flags);
433 	if (!addr_p)
434 		addr_p = of_get_address(of_node, bar_no, &max_size, &flags);
435 	if (!addr_p)
436 		return IOMEM_ERR_PTR(-ENODEV);
437 
438 	if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
439 		return IOMEM_ERR_PTR(-ENODEV);
440 
441 	if ((offset + size) >= max_size)
442 		return IOMEM_ERR_PTR(-ENODEV);
443 
444 	address = of_translate_address(of_node, addr_p);
445 	if (address == OF_BAD_ADDR)
446 		return IOMEM_ERR_PTR(-ENODEV);
447 
448 	mem = devm_ioremap(dev->dev, address + offset, size);
449 	if (!mem)
450 		return IOMEM_ERR_PTR(-ENOMEM);
451 
452 	return mem;
453 }
454 
455 static void __iomem *ofdrm_mach64_cmap_ioremap(struct ofdrm_device *odev,
456 					       struct device_node *of_node,
457 					       u64 fb_base)
458 {
459 	struct drm_device *dev = &odev->dev;
460 	u64 address;
461 	void __iomem *cmap_base;
462 
463 	address = fb_base & 0xff000000ul;
464 	address += 0x7ff000;
465 
466 	cmap_base = devm_ioremap(dev->dev, address, 0x1000);
467 	if (!cmap_base)
468 		return IOMEM_ERR_PTR(-ENOMEM);
469 
470 	return cmap_base;
471 }
472 
473 static void ofdrm_mach64_cmap_write(struct ofdrm_device *odev, unsigned char index,
474 				    unsigned char r, unsigned char g, unsigned char b)
475 {
476 	void __iomem *addr = odev->cmap_base + 0xcc0;
477 	void __iomem *data = odev->cmap_base + 0xcc0 + 1;
478 
479 	writeb(index, addr);
480 	writeb(r, data);
481 	writeb(g, data);
482 	writeb(b, data);
483 }
484 
485 static void __iomem *ofdrm_rage128_cmap_ioremap(struct ofdrm_device *odev,
486 						struct device_node *of_node,
487 						u64 fb_base)
488 {
489 	return get_cmap_address_of(odev, of_node, 2, 0, 0x1fff);
490 }
491 
492 static void ofdrm_rage128_cmap_write(struct ofdrm_device *odev, unsigned char index,
493 				     unsigned char r, unsigned char g, unsigned char b)
494 {
495 	void __iomem *addr = odev->cmap_base + 0xb0;
496 	void __iomem *data = odev->cmap_base + 0xb4;
497 	u32 color = (r << 16) | (g << 8) | b;
498 
499 	writeb(index, addr);
500 	writel(color, data);
501 }
502 
503 static void __iomem *ofdrm_rage_m3a_cmap_ioremap(struct ofdrm_device *odev,
504 						 struct device_node *of_node,
505 						 u64 fb_base)
506 {
507 	return get_cmap_address_of(odev, of_node, 2, 0, 0x1fff);
508 }
509 
510 static void ofdrm_rage_m3a_cmap_write(struct ofdrm_device *odev, unsigned char index,
511 				      unsigned char r, unsigned char g, unsigned char b)
512 {
513 	void __iomem *dac_ctl = odev->cmap_base + 0x58;
514 	void __iomem *addr = odev->cmap_base + 0xb0;
515 	void __iomem *data = odev->cmap_base + 0xb4;
516 	u32 color = (r << 16) | (g << 8) | b;
517 	u32 val;
518 
519 	/* Clear PALETTE_ACCESS_CNTL in DAC_CNTL */
520 	val = readl(dac_ctl);
521 	val &= ~0x20;
522 	writel(val, dac_ctl);
523 
524 	/* Set color at palette index */
525 	writeb(index, addr);
526 	writel(color, data);
527 }
528 
529 static void __iomem *ofdrm_rage_m3b_cmap_ioremap(struct ofdrm_device *odev,
530 						 struct device_node *of_node,
531 						 u64 fb_base)
532 {
533 	return get_cmap_address_of(odev, of_node, 2, 0, 0x1fff);
534 }
535 
536 static void ofdrm_rage_m3b_cmap_write(struct ofdrm_device *odev, unsigned char index,
537 				      unsigned char r, unsigned char g, unsigned char b)
538 {
539 	void __iomem *dac_ctl = odev->cmap_base + 0x58;
540 	void __iomem *addr = odev->cmap_base + 0xb0;
541 	void __iomem *data = odev->cmap_base + 0xb4;
542 	u32 color = (r << 16) | (g << 8) | b;
543 	u32 val;
544 
545 	/* Set PALETTE_ACCESS_CNTL in DAC_CNTL */
546 	val = readl(dac_ctl);
547 	val |= 0x20;
548 	writel(val, dac_ctl);
549 
550 	/* Set color at palette index */
551 	writeb(index, addr);
552 	writel(color, data);
553 }
554 
555 static void __iomem *ofdrm_radeon_cmap_ioremap(struct ofdrm_device *odev,
556 					       struct device_node *of_node,
557 					       u64 fb_base)
558 {
559 	return get_cmap_address_of(odev, of_node, 1, 0, 0x1fff);
560 }
561 
562 static void __iomem *ofdrm_gxt2000_cmap_ioremap(struct ofdrm_device *odev,
563 						struct device_node *of_node,
564 						u64 fb_base)
565 {
566 	return get_cmap_address_of(odev, of_node, 0, 0x6000, 0x1000);
567 }
568 
569 static void ofdrm_gxt2000_cmap_write(struct ofdrm_device *odev, unsigned char index,
570 				     unsigned char r, unsigned char g, unsigned char b)
571 {
572 	void __iomem *data = ((unsigned int __iomem *)odev->cmap_base) + index;
573 	u32 color = (r << 16) | (g << 8) | b;
574 
575 	writel(color, data);
576 }
577 
578 static void __iomem *ofdrm_avivo_cmap_ioremap(struct ofdrm_device *odev,
579 					      struct device_node *of_node,
580 					      u64 fb_base)
581 {
582 	struct device_node *of_parent;
583 	void __iomem *cmap_base;
584 
585 	of_parent = of_get_parent(of_node);
586 	cmap_base = get_cmap_address_of(odev, of_parent, 0, 0, 0x10000);
587 	of_node_put(of_parent);
588 
589 	return cmap_base;
590 }
591 
592 static void ofdrm_avivo_cmap_write(struct ofdrm_device *odev, unsigned char index,
593 				   unsigned char r, unsigned char g, unsigned char b)
594 {
595 	void __iomem *lutsel = odev->cmap_base + AVIVO_DC_LUT_RW_SELECT;
596 	void __iomem *addr = odev->cmap_base + AVIVO_DC_LUT_RW_INDEX;
597 	void __iomem *data = odev->cmap_base + AVIVO_DC_LUT_30_COLOR;
598 	u32 color = (r << 22) | (g << 12) | (b << 2);
599 
600 	/* Write to both LUTs for now */
601 
602 	writel(1, lutsel);
603 	writeb(index, addr);
604 	writel(color, data);
605 
606 	writel(0, lutsel);
607 	writeb(index, addr);
608 	writel(color, data);
609 }
610 
611 static void __iomem *ofdrm_qemu_cmap_ioremap(struct ofdrm_device *odev,
612 					     struct device_node *of_node,
613 					     u64 fb_base)
614 {
615 	static const __be32 io_of_addr[3] = {
616 		cpu_to_be32(0x01000000),
617 		cpu_to_be32(0x00),
618 		cpu_to_be32(0x00),
619 	};
620 
621 	struct drm_device *dev = &odev->dev;
622 	u64 address;
623 	void __iomem *cmap_base;
624 
625 	address = of_translate_address(of_node, io_of_addr);
626 	if (address == OF_BAD_ADDR)
627 		return IOMEM_ERR_PTR(-ENODEV);
628 
629 	cmap_base = devm_ioremap(dev->dev, address + 0x3c8, 2);
630 	if (!cmap_base)
631 		return IOMEM_ERR_PTR(-ENOMEM);
632 
633 	return cmap_base;
634 }
635 
636 static void ofdrm_qemu_cmap_write(struct ofdrm_device *odev, unsigned char index,
637 				  unsigned char r, unsigned char g, unsigned char b)
638 {
639 	void __iomem *addr = odev->cmap_base;
640 	void __iomem *data = odev->cmap_base + 1;
641 
642 	writeb(index, addr);
643 	writeb(r, data);
644 	writeb(g, data);
645 	writeb(b, data);
646 }
647 
648 static void ofdrm_device_set_gamma_linear(struct ofdrm_device *odev,
649 					  const struct drm_format_info *format)
650 {
651 	struct drm_device *dev = &odev->dev;
652 	int i;
653 
654 	switch (format->format) {
655 	case DRM_FORMAT_RGB565:
656 	case DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN:
657 		/* Use better interpolation, to take 32 values from 0 to 255 */
658 		for (i = 0; i < OFDRM_GAMMA_LUT_SIZE / 8; i++) {
659 			unsigned char r = i * 8 + i / 4;
660 			unsigned char g = i * 4 + i / 16;
661 			unsigned char b = i * 8 + i / 4;
662 
663 			odev->funcs->cmap_write(odev, i, r, g, b);
664 		}
665 		/* Green has one more bit, so add padding with 0 for red and blue. */
666 		for (i = OFDRM_GAMMA_LUT_SIZE / 8; i < OFDRM_GAMMA_LUT_SIZE / 4; i++) {
667 			unsigned char r = 0;
668 			unsigned char g = i * 4 + i / 16;
669 			unsigned char b = 0;
670 
671 			odev->funcs->cmap_write(odev, i, r, g, b);
672 		}
673 		break;
674 	case DRM_FORMAT_XRGB8888:
675 	case DRM_FORMAT_BGRX8888:
676 		for (i = 0; i < OFDRM_GAMMA_LUT_SIZE; i++)
677 			odev->funcs->cmap_write(odev, i, i, i, i);
678 		break;
679 	default:
680 		drm_warn_once(dev, "Unsupported format %p4cc for gamma correction\n",
681 			      &format->format);
682 		break;
683 	}
684 }
685 
686 static void ofdrm_device_set_gamma(struct ofdrm_device *odev,
687 				   const struct drm_format_info *format,
688 				   struct drm_color_lut *lut)
689 {
690 	struct drm_device *dev = &odev->dev;
691 	int i;
692 
693 	switch (format->format) {
694 	case DRM_FORMAT_RGB565:
695 	case DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN:
696 		/* Use better interpolation, to take 32 values from lut[0] to lut[255] */
697 		for (i = 0; i < OFDRM_GAMMA_LUT_SIZE / 8; i++) {
698 			unsigned char r = lut[i * 8 + i / 4].red >> 8;
699 			unsigned char g = lut[i * 4 + i / 16].green >> 8;
700 			unsigned char b = lut[i * 8 + i / 4].blue >> 8;
701 
702 			odev->funcs->cmap_write(odev, i, r, g, b);
703 		}
704 		/* Green has one more bit, so add padding with 0 for red and blue. */
705 		for (i = OFDRM_GAMMA_LUT_SIZE / 8; i < OFDRM_GAMMA_LUT_SIZE / 4; i++) {
706 			unsigned char r = 0;
707 			unsigned char g = lut[i * 4 + i / 16].green >> 8;
708 			unsigned char b = 0;
709 
710 			odev->funcs->cmap_write(odev, i, r, g, b);
711 		}
712 		break;
713 	case DRM_FORMAT_XRGB8888:
714 	case DRM_FORMAT_BGRX8888:
715 		for (i = 0; i < OFDRM_GAMMA_LUT_SIZE; i++) {
716 			unsigned char r = lut[i].red >> 8;
717 			unsigned char g = lut[i].green >> 8;
718 			unsigned char b = lut[i].blue >> 8;
719 
720 			odev->funcs->cmap_write(odev, i, r, g, b);
721 		}
722 		break;
723 	default:
724 		drm_warn_once(dev, "Unsupported format %p4cc for gamma correction\n",
725 			      &format->format);
726 		break;
727 	}
728 }
729 
730 /*
731  * Modesetting
732  */
733 
734 struct ofdrm_crtc_state {
735 	struct drm_crtc_state base;
736 
737 	/* Primary-plane format; required for color mgmt. */
738 	const struct drm_format_info *format;
739 };
740 
741 static struct ofdrm_crtc_state *to_ofdrm_crtc_state(struct drm_crtc_state *base)
742 {
743 	return container_of(base, struct ofdrm_crtc_state, base);
744 }
745 
746 static void ofdrm_crtc_state_destroy(struct ofdrm_crtc_state *ofdrm_crtc_state)
747 {
748 	__drm_atomic_helper_crtc_destroy_state(&ofdrm_crtc_state->base);
749 	kfree(ofdrm_crtc_state);
750 }
751 
752 static const uint64_t ofdrm_primary_plane_format_modifiers[] = {
753 	DRM_FORMAT_MOD_LINEAR,
754 	DRM_FORMAT_MOD_INVALID
755 };
756 
757 static int ofdrm_primary_plane_helper_atomic_check(struct drm_plane *plane,
758 						   struct drm_atomic_state *new_state)
759 {
760 	struct drm_device *dev = plane->dev;
761 	struct ofdrm_device *odev = ofdrm_device_of_dev(dev);
762 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(new_state, plane);
763 	struct drm_shadow_plane_state *new_shadow_plane_state =
764 		to_drm_shadow_plane_state(new_plane_state);
765 	struct drm_framebuffer *new_fb = new_plane_state->fb;
766 	struct drm_crtc *new_crtc = new_plane_state->crtc;
767 	struct drm_crtc_state *new_crtc_state = NULL;
768 	struct ofdrm_crtc_state *new_ofdrm_crtc_state;
769 	int ret;
770 
771 	if (new_crtc)
772 		new_crtc_state = drm_atomic_get_new_crtc_state(new_state, new_plane_state->crtc);
773 
774 	ret = drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
775 						  DRM_PLANE_NO_SCALING,
776 						  DRM_PLANE_NO_SCALING,
777 						  false, false);
778 	if (ret)
779 		return ret;
780 	else if (!new_plane_state->visible)
781 		return 0;
782 
783 	if (new_fb->format != odev->format) {
784 		void *buf;
785 
786 		/* format conversion necessary; reserve buffer */
787 		buf = drm_format_conv_state_reserve(&new_shadow_plane_state->fmtcnv_state,
788 						    odev->pitch, GFP_KERNEL);
789 		if (!buf)
790 			return -ENOMEM;
791 	}
792 
793 	new_crtc_state = drm_atomic_get_new_crtc_state(new_state, new_plane_state->crtc);
794 
795 	new_ofdrm_crtc_state = to_ofdrm_crtc_state(new_crtc_state);
796 	new_ofdrm_crtc_state->format = new_fb->format;
797 
798 	return 0;
799 }
800 
801 static void ofdrm_primary_plane_helper_atomic_update(struct drm_plane *plane,
802 						     struct drm_atomic_state *state)
803 {
804 	struct drm_device *dev = plane->dev;
805 	struct ofdrm_device *odev = ofdrm_device_of_dev(dev);
806 	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
807 	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
808 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
809 	struct drm_framebuffer *fb = plane_state->fb;
810 	unsigned int dst_pitch = odev->pitch;
811 	const struct drm_format_info *dst_format = odev->format;
812 	struct drm_atomic_helper_damage_iter iter;
813 	struct drm_rect damage;
814 	int ret, idx;
815 
816 	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
817 	if (ret)
818 		return;
819 
820 	if (!drm_dev_enter(dev, &idx))
821 		goto out_drm_gem_fb_end_cpu_access;
822 
823 	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
824 	drm_atomic_for_each_plane_damage(&iter, &damage) {
825 		struct iosys_map dst = odev->screen_base;
826 		struct drm_rect dst_clip = plane_state->dst;
827 
828 		if (!drm_rect_intersect(&dst_clip, &damage))
829 			continue;
830 
831 		iosys_map_incr(&dst, drm_fb_clip_offset(dst_pitch, dst_format, &dst_clip));
832 		drm_fb_blit(&dst, &dst_pitch, dst_format->format, shadow_plane_state->data, fb,
833 			    &damage, &shadow_plane_state->fmtcnv_state);
834 	}
835 
836 	drm_dev_exit(idx);
837 out_drm_gem_fb_end_cpu_access:
838 	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
839 }
840 
841 static void ofdrm_primary_plane_helper_atomic_disable(struct drm_plane *plane,
842 						      struct drm_atomic_state *state)
843 {
844 	struct drm_device *dev = plane->dev;
845 	struct ofdrm_device *odev = ofdrm_device_of_dev(dev);
846 	struct iosys_map dst = odev->screen_base;
847 	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
848 	void __iomem *dst_vmap = dst.vaddr_iomem; /* TODO: Use mapping abstraction */
849 	unsigned int dst_pitch = odev->pitch;
850 	const struct drm_format_info *dst_format = odev->format;
851 	struct drm_rect dst_clip;
852 	unsigned long lines, linepixels, i;
853 	int idx;
854 
855 	drm_rect_init(&dst_clip,
856 		      plane_state->src_x >> 16, plane_state->src_y >> 16,
857 		      plane_state->src_w >> 16, plane_state->src_h >> 16);
858 
859 	lines = drm_rect_height(&dst_clip);
860 	linepixels = drm_rect_width(&dst_clip);
861 
862 	if (!drm_dev_enter(dev, &idx))
863 		return;
864 
865 	/* Clear buffer to black if disabled */
866 	dst_vmap += drm_fb_clip_offset(dst_pitch, dst_format, &dst_clip);
867 	for (i = 0; i < lines; ++i) {
868 		memset_io(dst_vmap, 0, linepixels * dst_format->cpp[0]);
869 		dst_vmap += dst_pitch;
870 	}
871 
872 	drm_dev_exit(idx);
873 }
874 
875 static const struct drm_plane_helper_funcs ofdrm_primary_plane_helper_funcs = {
876 	DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
877 	.atomic_check = ofdrm_primary_plane_helper_atomic_check,
878 	.atomic_update = ofdrm_primary_plane_helper_atomic_update,
879 	.atomic_disable = ofdrm_primary_plane_helper_atomic_disable,
880 };
881 
882 static const struct drm_plane_funcs ofdrm_primary_plane_funcs = {
883 	.update_plane = drm_atomic_helper_update_plane,
884 	.disable_plane = drm_atomic_helper_disable_plane,
885 	.destroy = drm_plane_cleanup,
886 	DRM_GEM_SHADOW_PLANE_FUNCS,
887 };
888 
889 static enum drm_mode_status ofdrm_crtc_helper_mode_valid(struct drm_crtc *crtc,
890 							 const struct drm_display_mode *mode)
891 {
892 	struct ofdrm_device *odev = ofdrm_device_of_dev(crtc->dev);
893 
894 	return drm_crtc_helper_mode_valid_fixed(crtc, mode, &odev->mode);
895 }
896 
897 static int ofdrm_crtc_helper_atomic_check(struct drm_crtc *crtc,
898 					  struct drm_atomic_state *new_state)
899 {
900 	static const size_t gamma_lut_length = OFDRM_GAMMA_LUT_SIZE * sizeof(struct drm_color_lut);
901 
902 	struct drm_device *dev = crtc->dev;
903 	struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(new_state, crtc);
904 	int ret;
905 
906 	if (!new_crtc_state->enable)
907 		return 0;
908 
909 	ret = drm_atomic_helper_check_crtc_primary_plane(new_crtc_state);
910 	if (ret)
911 		return ret;
912 
913 	if (new_crtc_state->color_mgmt_changed) {
914 		struct drm_property_blob *gamma_lut = new_crtc_state->gamma_lut;
915 
916 		if (gamma_lut && (gamma_lut->length != gamma_lut_length)) {
917 			drm_dbg(dev, "Incorrect gamma_lut length %zu\n", gamma_lut->length);
918 			return -EINVAL;
919 		}
920 	}
921 
922 	return 0;
923 }
924 
925 static void ofdrm_crtc_helper_atomic_flush(struct drm_crtc *crtc, struct drm_atomic_state *state)
926 {
927 	struct ofdrm_device *odev = ofdrm_device_of_dev(crtc->dev);
928 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
929 	struct ofdrm_crtc_state *ofdrm_crtc_state = to_ofdrm_crtc_state(crtc_state);
930 
931 	if (crtc_state->enable && crtc_state->color_mgmt_changed) {
932 		const struct drm_format_info *format = ofdrm_crtc_state->format;
933 
934 		if (crtc_state->gamma_lut)
935 			ofdrm_device_set_gamma(odev, format, crtc_state->gamma_lut->data);
936 		else
937 			ofdrm_device_set_gamma_linear(odev, format);
938 	}
939 }
940 
941 /*
942  * The CRTC is always enabled. Screen updates are performed by
943  * the primary plane's atomic_update function. Disabling clears
944  * the screen in the primary plane's atomic_disable function.
945  */
946 static const struct drm_crtc_helper_funcs ofdrm_crtc_helper_funcs = {
947 	.mode_valid = ofdrm_crtc_helper_mode_valid,
948 	.atomic_check = ofdrm_crtc_helper_atomic_check,
949 	.atomic_flush = ofdrm_crtc_helper_atomic_flush,
950 };
951 
952 static void ofdrm_crtc_reset(struct drm_crtc *crtc)
953 {
954 	struct ofdrm_crtc_state *ofdrm_crtc_state =
955 		kzalloc(sizeof(*ofdrm_crtc_state), GFP_KERNEL);
956 
957 	if (crtc->state)
958 		ofdrm_crtc_state_destroy(to_ofdrm_crtc_state(crtc->state));
959 
960 	if (ofdrm_crtc_state)
961 		__drm_atomic_helper_crtc_reset(crtc, &ofdrm_crtc_state->base);
962 	else
963 		__drm_atomic_helper_crtc_reset(crtc, NULL);
964 }
965 
966 static struct drm_crtc_state *ofdrm_crtc_atomic_duplicate_state(struct drm_crtc *crtc)
967 {
968 	struct drm_device *dev = crtc->dev;
969 	struct drm_crtc_state *crtc_state = crtc->state;
970 	struct ofdrm_crtc_state *new_ofdrm_crtc_state;
971 	struct ofdrm_crtc_state *ofdrm_crtc_state;
972 
973 	if (drm_WARN_ON(dev, !crtc_state))
974 		return NULL;
975 
976 	new_ofdrm_crtc_state = kzalloc(sizeof(*new_ofdrm_crtc_state), GFP_KERNEL);
977 	if (!new_ofdrm_crtc_state)
978 		return NULL;
979 
980 	ofdrm_crtc_state = to_ofdrm_crtc_state(crtc_state);
981 
982 	__drm_atomic_helper_crtc_duplicate_state(crtc, &new_ofdrm_crtc_state->base);
983 	new_ofdrm_crtc_state->format = ofdrm_crtc_state->format;
984 
985 	return &new_ofdrm_crtc_state->base;
986 }
987 
988 static void ofdrm_crtc_atomic_destroy_state(struct drm_crtc *crtc,
989 					    struct drm_crtc_state *crtc_state)
990 {
991 	ofdrm_crtc_state_destroy(to_ofdrm_crtc_state(crtc_state));
992 }
993 
994 static const struct drm_crtc_funcs ofdrm_crtc_funcs = {
995 	.reset = ofdrm_crtc_reset,
996 	.destroy = drm_crtc_cleanup,
997 	.set_config = drm_atomic_helper_set_config,
998 	.page_flip = drm_atomic_helper_page_flip,
999 	.atomic_duplicate_state = ofdrm_crtc_atomic_duplicate_state,
1000 	.atomic_destroy_state = ofdrm_crtc_atomic_destroy_state,
1001 };
1002 
1003 static int ofdrm_connector_helper_get_modes(struct drm_connector *connector)
1004 {
1005 	struct ofdrm_device *odev = ofdrm_device_of_dev(connector->dev);
1006 
1007 	return drm_connector_helper_get_modes_fixed(connector, &odev->mode);
1008 }
1009 
1010 static const struct drm_connector_helper_funcs ofdrm_connector_helper_funcs = {
1011 	.get_modes = ofdrm_connector_helper_get_modes,
1012 };
1013 
1014 static const struct drm_connector_funcs ofdrm_connector_funcs = {
1015 	.reset = drm_atomic_helper_connector_reset,
1016 	.fill_modes = drm_helper_probe_single_connector_modes,
1017 	.destroy = drm_connector_cleanup,
1018 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
1019 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
1020 };
1021 
1022 static const struct drm_mode_config_funcs ofdrm_mode_config_funcs = {
1023 	.fb_create = drm_gem_fb_create_with_dirty,
1024 	.atomic_check = drm_atomic_helper_check,
1025 	.atomic_commit = drm_atomic_helper_commit,
1026 };
1027 
1028 /*
1029  * Init / Cleanup
1030  */
1031 
1032 static const struct ofdrm_device_funcs ofdrm_unknown_device_funcs = {
1033 };
1034 
1035 static const struct ofdrm_device_funcs ofdrm_mach64_device_funcs = {
1036 	.cmap_ioremap = ofdrm_mach64_cmap_ioremap,
1037 	.cmap_write = ofdrm_mach64_cmap_write,
1038 };
1039 
1040 static const struct ofdrm_device_funcs ofdrm_rage128_device_funcs = {
1041 	.cmap_ioremap = ofdrm_rage128_cmap_ioremap,
1042 	.cmap_write = ofdrm_rage128_cmap_write,
1043 };
1044 
1045 static const struct ofdrm_device_funcs ofdrm_rage_m3a_device_funcs = {
1046 	.cmap_ioremap = ofdrm_rage_m3a_cmap_ioremap,
1047 	.cmap_write = ofdrm_rage_m3a_cmap_write,
1048 };
1049 
1050 static const struct ofdrm_device_funcs ofdrm_rage_m3b_device_funcs = {
1051 	.cmap_ioremap = ofdrm_rage_m3b_cmap_ioremap,
1052 	.cmap_write = ofdrm_rage_m3b_cmap_write,
1053 };
1054 
1055 static const struct ofdrm_device_funcs ofdrm_radeon_device_funcs = {
1056 	.cmap_ioremap = ofdrm_radeon_cmap_ioremap,
1057 	.cmap_write = ofdrm_rage128_cmap_write, /* same as Rage128 */
1058 };
1059 
1060 static const struct ofdrm_device_funcs ofdrm_gxt2000_device_funcs = {
1061 	.cmap_ioremap = ofdrm_gxt2000_cmap_ioremap,
1062 	.cmap_write = ofdrm_gxt2000_cmap_write,
1063 };
1064 
1065 static const struct ofdrm_device_funcs ofdrm_avivo_device_funcs = {
1066 	.cmap_ioremap = ofdrm_avivo_cmap_ioremap,
1067 	.cmap_write = ofdrm_avivo_cmap_write,
1068 };
1069 
1070 static const struct ofdrm_device_funcs ofdrm_qemu_device_funcs = {
1071 	.cmap_ioremap = ofdrm_qemu_cmap_ioremap,
1072 	.cmap_write = ofdrm_qemu_cmap_write,
1073 };
1074 
1075 static struct drm_display_mode ofdrm_mode(unsigned int width, unsigned int height)
1076 {
1077 	/*
1078 	 * Assume a monitor resolution of 96 dpi to
1079 	 * get a somewhat reasonable screen size.
1080 	 */
1081 	const struct drm_display_mode mode = {
1082 		DRM_MODE_INIT(60, width, height,
1083 			      DRM_MODE_RES_MM(width, 96ul),
1084 			      DRM_MODE_RES_MM(height, 96ul))
1085 	};
1086 
1087 	return mode;
1088 }
1089 
1090 static struct ofdrm_device *ofdrm_device_create(struct drm_driver *drv,
1091 						struct platform_device *pdev)
1092 {
1093 	struct device_node *of_node = pdev->dev.of_node;
1094 	struct ofdrm_device *odev;
1095 	struct drm_device *dev;
1096 	enum ofdrm_model model;
1097 	bool big_endian;
1098 	int width, height, depth, linebytes;
1099 	const struct drm_format_info *format;
1100 	u64 address;
1101 	resource_size_t fb_size, fb_base, fb_pgbase, fb_pgsize;
1102 	struct resource *res, *mem;
1103 	void __iomem *screen_base;
1104 	struct drm_plane *primary_plane;
1105 	struct drm_crtc *crtc;
1106 	struct drm_encoder *encoder;
1107 	struct drm_connector *connector;
1108 	unsigned long max_width, max_height;
1109 	size_t nformats;
1110 	int ret;
1111 
1112 	odev = devm_drm_dev_alloc(&pdev->dev, drv, struct ofdrm_device, dev);
1113 	if (IS_ERR(odev))
1114 		return ERR_CAST(odev);
1115 	dev = &odev->dev;
1116 	platform_set_drvdata(pdev, dev);
1117 
1118 	ret = ofdrm_device_init_pci(odev);
1119 	if (ret)
1120 		return ERR_PTR(ret);
1121 
1122 	/*
1123 	 * OF display-node settings
1124 	 */
1125 
1126 	model = display_get_model_of(dev, of_node);
1127 	drm_dbg(dev, "detected model %d\n", model);
1128 
1129 	switch (model) {
1130 	case OFDRM_MODEL_UNKNOWN:
1131 		odev->funcs = &ofdrm_unknown_device_funcs;
1132 		break;
1133 	case OFDRM_MODEL_MACH64:
1134 		odev->funcs = &ofdrm_mach64_device_funcs;
1135 		break;
1136 	case OFDRM_MODEL_RAGE128:
1137 		odev->funcs = &ofdrm_rage128_device_funcs;
1138 		break;
1139 	case OFDRM_MODEL_RAGE_M3A:
1140 		odev->funcs = &ofdrm_rage_m3a_device_funcs;
1141 		break;
1142 	case OFDRM_MODEL_RAGE_M3B:
1143 		odev->funcs = &ofdrm_rage_m3b_device_funcs;
1144 		break;
1145 	case OFDRM_MODEL_RADEON:
1146 		odev->funcs = &ofdrm_radeon_device_funcs;
1147 		break;
1148 	case OFDRM_MODEL_GXT2000:
1149 		odev->funcs = &ofdrm_gxt2000_device_funcs;
1150 		break;
1151 	case OFDRM_MODEL_AVIVO:
1152 		odev->funcs = &ofdrm_avivo_device_funcs;
1153 		break;
1154 	case OFDRM_MODEL_QEMU:
1155 		odev->funcs = &ofdrm_qemu_device_funcs;
1156 		break;
1157 	}
1158 
1159 	big_endian = display_get_big_endian_of(dev, of_node);
1160 
1161 	width = display_get_width_of(dev, of_node);
1162 	if (width < 0)
1163 		return ERR_PTR(width);
1164 	height = display_get_height_of(dev, of_node);
1165 	if (height < 0)
1166 		return ERR_PTR(height);
1167 	depth = display_get_depth_of(dev, of_node);
1168 	if (depth < 0)
1169 		return ERR_PTR(depth);
1170 	linebytes = display_get_linebytes_of(dev, of_node);
1171 	if (linebytes < 0)
1172 		return ERR_PTR(linebytes);
1173 
1174 	format = display_get_validated_format(dev, depth, big_endian);
1175 	if (IS_ERR(format))
1176 		return ERR_CAST(format);
1177 	if (!linebytes) {
1178 		linebytes = drm_format_info_min_pitch(format, 0, width);
1179 		if (drm_WARN_ON(dev, !linebytes))
1180 			return ERR_PTR(-EINVAL);
1181 	}
1182 
1183 	fb_size = linebytes * height;
1184 
1185 	/*
1186 	 * Try to figure out the address of the framebuffer. Unfortunately, Open
1187 	 * Firmware doesn't provide a standard way to do so. All we can do is a
1188 	 * dodgy heuristic that happens to work in practice.
1189 	 *
1190 	 * On most machines, the "address" property contains what we need, though
1191 	 * not on Matrox cards found in IBM machines. What appears to give good
1192 	 * results is to go through the PCI ranges and pick one that encloses the
1193 	 * "address" property. If none match, we pick the largest.
1194 	 */
1195 	address = display_get_address_of(dev, of_node);
1196 	if (address != OF_BAD_ADDR) {
1197 		struct resource fb_res = DEFINE_RES_MEM(address, fb_size);
1198 
1199 		res = ofdrm_find_fb_resource(odev, &fb_res);
1200 		if (!res)
1201 			return ERR_PTR(-EINVAL);
1202 		if (resource_contains(res, &fb_res))
1203 			fb_base = address;
1204 		else
1205 			fb_base = res->start;
1206 	} else {
1207 		struct resource fb_res = DEFINE_RES_MEM(0u, fb_size);
1208 
1209 		res = ofdrm_find_fb_resource(odev, &fb_res);
1210 		if (!res)
1211 			return ERR_PTR(-EINVAL);
1212 		fb_base = res->start;
1213 	}
1214 
1215 	/*
1216 	 * I/O resources
1217 	 */
1218 
1219 	fb_pgbase = round_down(fb_base, PAGE_SIZE);
1220 	fb_pgsize = fb_base - fb_pgbase + round_up(fb_size, PAGE_SIZE);
1221 
1222 	ret = devm_aperture_acquire_from_firmware(dev, fb_pgbase, fb_pgsize);
1223 	if (ret) {
1224 		drm_err(dev, "could not acquire memory range %pr: error %d\n", &res, ret);
1225 		return ERR_PTR(ret);
1226 	}
1227 
1228 	mem = devm_request_mem_region(&pdev->dev, fb_pgbase, fb_pgsize, drv->name);
1229 	if (!mem) {
1230 		drm_warn(dev, "could not acquire memory region %pr\n", &res);
1231 		return ERR_PTR(-ENOMEM);
1232 	}
1233 
1234 	screen_base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
1235 	if (!screen_base)
1236 		return ERR_PTR(-ENOMEM);
1237 
1238 	if (odev->funcs->cmap_ioremap) {
1239 		void __iomem *cmap_base = odev->funcs->cmap_ioremap(odev, of_node, fb_base);
1240 
1241 		if (IS_ERR(cmap_base)) {
1242 			/* Don't fail; continue without colormap */
1243 			drm_warn(dev, "could not find colormap: error %ld\n", PTR_ERR(cmap_base));
1244 		} else {
1245 			odev->cmap_base = cmap_base;
1246 		}
1247 	}
1248 
1249 	/*
1250 	 * Firmware framebuffer
1251 	 */
1252 
1253 	iosys_map_set_vaddr_iomem(&odev->screen_base, screen_base);
1254 	odev->mode = ofdrm_mode(width, height);
1255 	odev->format = format;
1256 	odev->pitch = linebytes;
1257 
1258 	drm_dbg(dev, "display mode={" DRM_MODE_FMT "}\n", DRM_MODE_ARG(&odev->mode));
1259 	drm_dbg(dev, "framebuffer format=%p4cc, size=%dx%d, linebytes=%d byte\n",
1260 		&format->format, width, height, linebytes);
1261 
1262 	/*
1263 	 * Mode-setting pipeline
1264 	 */
1265 
1266 	ret = drmm_mode_config_init(dev);
1267 	if (ret)
1268 		return ERR_PTR(ret);
1269 
1270 	max_width = max_t(unsigned long, width, DRM_SHADOW_PLANE_MAX_WIDTH);
1271 	max_height = max_t(unsigned long, height, DRM_SHADOW_PLANE_MAX_HEIGHT);
1272 
1273 	dev->mode_config.min_width = width;
1274 	dev->mode_config.max_width = max_width;
1275 	dev->mode_config.min_height = height;
1276 	dev->mode_config.max_height = max_height;
1277 	dev->mode_config.funcs = &ofdrm_mode_config_funcs;
1278 	dev->mode_config.preferred_depth = format->depth;
1279 	dev->mode_config.quirk_addfb_prefer_host_byte_order = true;
1280 
1281 	/* Primary plane */
1282 
1283 	nformats = drm_fb_build_fourcc_list(dev, &format->format, 1,
1284 					    odev->formats, ARRAY_SIZE(odev->formats));
1285 
1286 	primary_plane = &odev->primary_plane;
1287 	ret = drm_universal_plane_init(dev, primary_plane, 0, &ofdrm_primary_plane_funcs,
1288 				       odev->formats, nformats,
1289 				       ofdrm_primary_plane_format_modifiers,
1290 				       DRM_PLANE_TYPE_PRIMARY, NULL);
1291 	if (ret)
1292 		return ERR_PTR(ret);
1293 	drm_plane_helper_add(primary_plane, &ofdrm_primary_plane_helper_funcs);
1294 	drm_plane_enable_fb_damage_clips(primary_plane);
1295 
1296 	/* CRTC */
1297 
1298 	crtc = &odev->crtc;
1299 	ret = drm_crtc_init_with_planes(dev, crtc, primary_plane, NULL,
1300 					&ofdrm_crtc_funcs, NULL);
1301 	if (ret)
1302 		return ERR_PTR(ret);
1303 	drm_crtc_helper_add(crtc, &ofdrm_crtc_helper_funcs);
1304 
1305 	if (odev->cmap_base) {
1306 		drm_mode_crtc_set_gamma_size(crtc, OFDRM_GAMMA_LUT_SIZE);
1307 		drm_crtc_enable_color_mgmt(crtc, 0, false, OFDRM_GAMMA_LUT_SIZE);
1308 	}
1309 
1310 	/* Encoder */
1311 
1312 	encoder = &odev->encoder;
1313 	ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE);
1314 	if (ret)
1315 		return ERR_PTR(ret);
1316 	encoder->possible_crtcs = drm_crtc_mask(crtc);
1317 
1318 	/* Connector */
1319 
1320 	connector = &odev->connector;
1321 	ret = drm_connector_init(dev, connector, &ofdrm_connector_funcs,
1322 				 DRM_MODE_CONNECTOR_Unknown);
1323 	if (ret)
1324 		return ERR_PTR(ret);
1325 	drm_connector_helper_add(connector, &ofdrm_connector_helper_funcs);
1326 	drm_connector_set_panel_orientation_with_quirk(connector,
1327 						       DRM_MODE_PANEL_ORIENTATION_UNKNOWN,
1328 						       width, height);
1329 
1330 	ret = drm_connector_attach_encoder(connector, encoder);
1331 	if (ret)
1332 		return ERR_PTR(ret);
1333 
1334 	drm_mode_config_reset(dev);
1335 
1336 	return odev;
1337 }
1338 
1339 /*
1340  * DRM driver
1341  */
1342 
1343 DEFINE_DRM_GEM_FOPS(ofdrm_fops);
1344 
1345 static struct drm_driver ofdrm_driver = {
1346 	DRM_GEM_SHMEM_DRIVER_OPS,
1347 	.name			= DRIVER_NAME,
1348 	.desc			= DRIVER_DESC,
1349 	.date			= DRIVER_DATE,
1350 	.major			= DRIVER_MAJOR,
1351 	.minor			= DRIVER_MINOR,
1352 	.driver_features	= DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
1353 	.fops			= &ofdrm_fops,
1354 };
1355 
1356 /*
1357  * Platform driver
1358  */
1359 
1360 static int ofdrm_probe(struct platform_device *pdev)
1361 {
1362 	struct ofdrm_device *odev;
1363 	struct drm_device *dev;
1364 	unsigned int color_mode;
1365 	int ret;
1366 
1367 	odev = ofdrm_device_create(&ofdrm_driver, pdev);
1368 	if (IS_ERR(odev))
1369 		return PTR_ERR(odev);
1370 	dev = &odev->dev;
1371 
1372 	ret = drm_dev_register(dev, 0);
1373 	if (ret)
1374 		return ret;
1375 
1376 	color_mode = drm_format_info_bpp(odev->format, 0);
1377 	if (color_mode == 16)
1378 		color_mode = odev->format->depth; // can be 15 or 16
1379 
1380 	drm_fbdev_generic_setup(dev, color_mode);
1381 
1382 	return 0;
1383 }
1384 
1385 static void ofdrm_remove(struct platform_device *pdev)
1386 {
1387 	struct drm_device *dev = platform_get_drvdata(pdev);
1388 
1389 	drm_dev_unplug(dev);
1390 }
1391 
1392 static const struct of_device_id ofdrm_of_match_display[] = {
1393 	{ .compatible = "display", },
1394 	{ },
1395 };
1396 MODULE_DEVICE_TABLE(of, ofdrm_of_match_display);
1397 
1398 static struct platform_driver ofdrm_platform_driver = {
1399 	.driver = {
1400 		.name = "of-display",
1401 		.of_match_table = ofdrm_of_match_display,
1402 	},
1403 	.probe = ofdrm_probe,
1404 	.remove_new = ofdrm_remove,
1405 };
1406 
1407 module_platform_driver(ofdrm_platform_driver);
1408 
1409 MODULE_DESCRIPTION(DRIVER_DESC);
1410 MODULE_LICENSE("GPL");
1411