xref: /openbmc/linux/drivers/gpu/drm/tiny/ofdrm.c (revision a9ebfc40)
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_plane_helper.h>
23 #include <drm/drm_probe_helper.h>
24 #include <drm/drm_simple_kms_helper.h>
25 
26 #define DRIVER_NAME	"ofdrm"
27 #define DRIVER_DESC	"DRM driver for OF platform devices"
28 #define DRIVER_DATE	"20220501"
29 #define DRIVER_MAJOR	1
30 #define DRIVER_MINOR	0
31 
32 #define PCI_VENDOR_ID_ATI_R520	0x7100
33 #define PCI_VENDOR_ID_ATI_R600	0x9400
34 
35 #define OFDRM_GAMMA_LUT_SIZE	256
36 
37 /* Definitions used by the Avivo palette  */
38 #define AVIVO_DC_LUT_RW_SELECT                  0x6480
39 #define AVIVO_DC_LUT_RW_MODE                    0x6484
40 #define AVIVO_DC_LUT_RW_INDEX                   0x6488
41 #define AVIVO_DC_LUT_SEQ_COLOR                  0x648c
42 #define AVIVO_DC_LUT_PWL_DATA                   0x6490
43 #define AVIVO_DC_LUT_30_COLOR                   0x6494
44 #define AVIVO_DC_LUT_READ_PIPE_SELECT           0x6498
45 #define AVIVO_DC_LUT_WRITE_EN_MASK              0x649c
46 #define AVIVO_DC_LUT_AUTOFILL                   0x64a0
47 #define AVIVO_DC_LUTA_CONTROL                   0x64c0
48 #define AVIVO_DC_LUTA_BLACK_OFFSET_BLUE         0x64c4
49 #define AVIVO_DC_LUTA_BLACK_OFFSET_GREEN        0x64c8
50 #define AVIVO_DC_LUTA_BLACK_OFFSET_RED          0x64cc
51 #define AVIVO_DC_LUTA_WHITE_OFFSET_BLUE         0x64d0
52 #define AVIVO_DC_LUTA_WHITE_OFFSET_GREEN        0x64d4
53 #define AVIVO_DC_LUTA_WHITE_OFFSET_RED          0x64d8
54 #define AVIVO_DC_LUTB_CONTROL                   0x6cc0
55 #define AVIVO_DC_LUTB_BLACK_OFFSET_BLUE         0x6cc4
56 #define AVIVO_DC_LUTB_BLACK_OFFSET_GREEN        0x6cc8
57 #define AVIVO_DC_LUTB_BLACK_OFFSET_RED          0x6ccc
58 #define AVIVO_DC_LUTB_WHITE_OFFSET_BLUE         0x6cd0
59 #define AVIVO_DC_LUTB_WHITE_OFFSET_GREEN        0x6cd4
60 #define AVIVO_DC_LUTB_WHITE_OFFSET_RED          0x6cd8
61 
62 enum ofdrm_model {
63 	OFDRM_MODEL_UNKNOWN,
64 	OFDRM_MODEL_MACH64, /* ATI Mach64 */
65 	OFDRM_MODEL_RAGE128, /* ATI Rage128 */
66 	OFDRM_MODEL_RAGE_M3A, /* ATI Rage Mobility M3 Head A */
67 	OFDRM_MODEL_RAGE_M3B, /* ATI Rage Mobility M3 Head B */
68 	OFDRM_MODEL_RADEON, /* ATI Radeon */
69 	OFDRM_MODEL_GXT2000, /* IBM GXT2000 */
70 	OFDRM_MODEL_AVIVO, /* ATI R5xx */
71 	OFDRM_MODEL_QEMU, /* QEMU VGA */
72 };
73 
74 /*
75  * Helpers for display nodes
76  */
77 
78 static int display_get_validated_int(struct drm_device *dev, const char *name, uint32_t value)
79 {
80 	if (value > INT_MAX) {
81 		drm_err(dev, "invalid framebuffer %s of %u\n", name, value);
82 		return -EINVAL;
83 	}
84 	return (int)value;
85 }
86 
87 static int display_get_validated_int0(struct drm_device *dev, const char *name, uint32_t value)
88 {
89 	if (!value) {
90 		drm_err(dev, "invalid framebuffer %s of %u\n", name, value);
91 		return -EINVAL;
92 	}
93 	return display_get_validated_int(dev, name, value);
94 }
95 
96 static const struct drm_format_info *display_get_validated_format(struct drm_device *dev,
97 								  u32 depth, bool big_endian)
98 {
99 	const struct drm_format_info *info;
100 	u32 format;
101 
102 	switch (depth) {
103 	case 8:
104 		format = drm_mode_legacy_fb_format(8, 8);
105 		break;
106 	case 15:
107 	case 16:
108 		format = drm_mode_legacy_fb_format(16, depth);
109 		break;
110 	case 32:
111 		format = drm_mode_legacy_fb_format(32, 24);
112 		break;
113 	default:
114 		drm_err(dev, "unsupported framebuffer depth %u\n", depth);
115 		return ERR_PTR(-EINVAL);
116 	}
117 
118 	/*
119 	 * DRM formats assume little-endian byte order. Update the format
120 	 * if the scanout buffer uses big-endian ordering.
121 	 */
122 	if (big_endian) {
123 		switch (format) {
124 		case DRM_FORMAT_XRGB8888:
125 			format = DRM_FORMAT_BGRX8888;
126 			break;
127 		case DRM_FORMAT_ARGB8888:
128 			format = DRM_FORMAT_BGRA8888;
129 			break;
130 		case DRM_FORMAT_RGB565:
131 			format = DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN;
132 			break;
133 		case DRM_FORMAT_XRGB1555:
134 			format = DRM_FORMAT_XRGB1555 | DRM_FORMAT_BIG_ENDIAN;
135 			break;
136 		default:
137 			break;
138 		}
139 	}
140 
141 	info = drm_format_info(format);
142 	if (!info) {
143 		drm_err(dev, "cannot find framebuffer format for depth %u\n", depth);
144 		return ERR_PTR(-EINVAL);
145 	}
146 
147 	return info;
148 }
149 
150 static int display_read_u32_of(struct drm_device *dev, struct device_node *of_node,
151 			       const char *name, u32 *value)
152 {
153 	int ret = of_property_read_u32(of_node, name, value);
154 
155 	if (ret)
156 		drm_err(dev, "cannot parse framebuffer %s: error %d\n", name, ret);
157 	return ret;
158 }
159 
160 static bool display_get_big_endian_of(struct drm_device *dev, struct device_node *of_node)
161 {
162 	bool big_endian;
163 
164 #ifdef __BIG_ENDIAN
165 	big_endian = !of_property_read_bool(of_node, "little-endian");
166 #else
167 	big_endian = of_property_read_bool(of_node, "big-endian");
168 #endif
169 
170 	return big_endian;
171 }
172 
173 static int display_get_width_of(struct drm_device *dev, struct device_node *of_node)
174 {
175 	u32 width;
176 	int ret = display_read_u32_of(dev, of_node, "width", &width);
177 
178 	if (ret)
179 		return ret;
180 	return display_get_validated_int0(dev, "width", width);
181 }
182 
183 static int display_get_height_of(struct drm_device *dev, struct device_node *of_node)
184 {
185 	u32 height;
186 	int ret = display_read_u32_of(dev, of_node, "height", &height);
187 
188 	if (ret)
189 		return ret;
190 	return display_get_validated_int0(dev, "height", height);
191 }
192 
193 static int display_get_depth_of(struct drm_device *dev, struct device_node *of_node)
194 {
195 	u32 depth;
196 	int ret = display_read_u32_of(dev, of_node, "depth", &depth);
197 
198 	if (ret)
199 		return ret;
200 	return display_get_validated_int0(dev, "depth", depth);
201 }
202 
203 static int display_get_linebytes_of(struct drm_device *dev, struct device_node *of_node)
204 {
205 	u32 linebytes;
206 	int ret = display_read_u32_of(dev, of_node, "linebytes", &linebytes);
207 
208 	if (ret)
209 		return ret;
210 	return display_get_validated_int(dev, "linebytes", linebytes);
211 }
212 
213 static u64 display_get_address_of(struct drm_device *dev, struct device_node *of_node)
214 {
215 	u32 address;
216 	int ret;
217 
218 	/*
219 	 * Not all devices provide an address property, it's not
220 	 * a bug if this fails. The driver will try to find the
221 	 * framebuffer base address from the device's memory regions.
222 	 */
223 	ret = of_property_read_u32(of_node, "address", &address);
224 	if (ret)
225 		return OF_BAD_ADDR;
226 
227 	return address;
228 }
229 
230 static bool is_avivo(u32 vendor, u32 device)
231 {
232 	/* This will match most R5xx */
233 	return (vendor == PCI_VENDOR_ID_ATI) &&
234 	       ((device >= PCI_VENDOR_ID_ATI_R520 && device < 0x7800) ||
235 		(PCI_VENDOR_ID_ATI_R600 >= 0x9400));
236 }
237 
238 static enum ofdrm_model display_get_model_of(struct drm_device *dev, struct device_node *of_node)
239 {
240 	enum ofdrm_model model = OFDRM_MODEL_UNKNOWN;
241 
242 	if (of_node_name_prefix(of_node, "ATY,Rage128")) {
243 		model = OFDRM_MODEL_RAGE128;
244 	} else if (of_node_name_prefix(of_node, "ATY,RageM3pA") ||
245 		   of_node_name_prefix(of_node, "ATY,RageM3p12A")) {
246 		model = OFDRM_MODEL_RAGE_M3A;
247 	} else if (of_node_name_prefix(of_node, "ATY,RageM3pB")) {
248 		model = OFDRM_MODEL_RAGE_M3B;
249 	} else if (of_node_name_prefix(of_node, "ATY,Rage6")) {
250 		model = OFDRM_MODEL_RADEON;
251 	} else if (of_node_name_prefix(of_node, "ATY,")) {
252 		return OFDRM_MODEL_MACH64;
253 	} else if (of_device_is_compatible(of_node, "pci1014,b7") ||
254 		   of_device_is_compatible(of_node, "pci1014,21c")) {
255 		model = OFDRM_MODEL_GXT2000;
256 	} else if (of_node_name_prefix(of_node, "vga,Display-")) {
257 		struct device_node *of_parent;
258 		const __be32 *vendor_p, *device_p;
259 
260 		/* Look for AVIVO initialized by SLOF */
261 		of_parent = of_get_parent(of_node);
262 		vendor_p = of_get_property(of_parent, "vendor-id", NULL);
263 		device_p = of_get_property(of_parent, "device-id", NULL);
264 		if (vendor_p && device_p) {
265 			u32 vendor = be32_to_cpup(vendor_p);
266 			u32 device = be32_to_cpup(device_p);
267 
268 			if (is_avivo(vendor, device))
269 				model = OFDRM_MODEL_AVIVO;
270 		}
271 		of_node_put(of_parent);
272 	} else if (of_device_is_compatible(of_node, "qemu,std-vga")) {
273 		model = OFDRM_MODEL_QEMU;
274 	}
275 
276 	return model;
277 }
278 
279 /*
280  * Open Firmware display device
281  */
282 
283 struct ofdrm_device;
284 
285 struct ofdrm_device_funcs {
286 	void __iomem *(*cmap_ioremap)(struct ofdrm_device *odev,
287 				      struct device_node *of_node,
288 				      u64 fb_bas);
289 	void (*cmap_write)(struct ofdrm_device *odev, unsigned char index,
290 			   unsigned char r, unsigned char g, unsigned char b);
291 };
292 
293 struct ofdrm_device {
294 	struct drm_device dev;
295 	struct platform_device *pdev;
296 
297 	const struct ofdrm_device_funcs *funcs;
298 
299 	/* firmware-buffer settings */
300 	struct iosys_map screen_base;
301 	struct drm_display_mode mode;
302 	const struct drm_format_info *format;
303 	unsigned int pitch;
304 
305 	/* colormap */
306 	void __iomem *cmap_base;
307 
308 	/* modesetting */
309 	uint32_t formats[8];
310 	struct drm_plane primary_plane;
311 	struct drm_crtc crtc;
312 	struct drm_encoder encoder;
313 	struct drm_connector connector;
314 };
315 
316 static struct ofdrm_device *ofdrm_device_of_dev(struct drm_device *dev)
317 {
318 	return container_of(dev, struct ofdrm_device, dev);
319 }
320 
321 /*
322  * Hardware
323  */
324 
325 #if defined(CONFIG_PCI)
326 static struct pci_dev *display_get_pci_dev_of(struct drm_device *dev, struct device_node *of_node)
327 {
328 	const __be32 *vendor_p, *device_p;
329 	u32 vendor, device;
330 	struct pci_dev *pcidev;
331 
332 	vendor_p = of_get_property(of_node, "vendor-id", NULL);
333 	if (!vendor_p)
334 		return ERR_PTR(-ENODEV);
335 	vendor = be32_to_cpup(vendor_p);
336 
337 	device_p = of_get_property(of_node, "device-id", NULL);
338 	if (!device_p)
339 		return ERR_PTR(-ENODEV);
340 	device = be32_to_cpup(device_p);
341 
342 	pcidev = pci_get_device(vendor, device, NULL);
343 	if (!pcidev)
344 		return ERR_PTR(-ENODEV);
345 
346 	return pcidev;
347 }
348 
349 static void ofdrm_pci_release(void *data)
350 {
351 	struct pci_dev *pcidev = data;
352 
353 	pci_disable_device(pcidev);
354 }
355 
356 static int ofdrm_device_init_pci(struct ofdrm_device *odev)
357 {
358 	struct drm_device *dev = &odev->dev;
359 	struct platform_device *pdev = to_platform_device(dev->dev);
360 	struct device_node *of_node = pdev->dev.of_node;
361 	struct pci_dev *pcidev;
362 	int ret;
363 
364 	/*
365 	 * Never use pcim_ or other managed helpers on the returned PCI
366 	 * device. Otherwise, probing the native driver will fail for
367 	 * resource conflicts. PCI-device management has to be tied to
368 	 * the lifetime of the platform device until the native driver
369 	 * takes over.
370 	 */
371 	pcidev = display_get_pci_dev_of(dev, of_node);
372 	if (IS_ERR(pcidev))
373 		return 0; /* no PCI device found; ignore the error */
374 
375 	ret = pci_enable_device(pcidev);
376 	if (ret) {
377 		drm_err(dev, "pci_enable_device(%s) failed: %d\n",
378 			dev_name(&pcidev->dev), ret);
379 		return ret;
380 	}
381 	ret = devm_add_action_or_reset(&pdev->dev, ofdrm_pci_release, pcidev);
382 	if (ret)
383 		return ret;
384 
385 	return 0;
386 }
387 #else
388 static int ofdrm_device_init_pci(struct ofdrm_device *odev)
389 {
390 	return 0;
391 }
392 #endif
393 
394 /*
395  *  OF display settings
396  */
397 
398 static struct resource *ofdrm_find_fb_resource(struct ofdrm_device *odev,
399 					       struct resource *fb_res)
400 {
401 	struct platform_device *pdev = to_platform_device(odev->dev.dev);
402 	struct resource *res, *max_res = NULL;
403 	u32 i;
404 
405 	for (i = 0; pdev->num_resources; ++i) {
406 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
407 		if (!res)
408 			break; /* all resources processed */
409 		if (resource_size(res) < resource_size(fb_res))
410 			continue; /* resource too small */
411 		if (fb_res->start && resource_contains(res, fb_res))
412 			return res; /* resource contains framebuffer */
413 		if (!max_res || resource_size(res) > resource_size(max_res))
414 			max_res = res; /* store largest resource as fallback */
415 	}
416 
417 	return max_res;
418 }
419 
420 /*
421  * Colormap / Palette
422  */
423 
424 static void __iomem *get_cmap_address_of(struct ofdrm_device *odev, struct device_node *of_node,
425 					 int bar_no, unsigned long offset, unsigned long size)
426 {
427 	struct drm_device *dev = &odev->dev;
428 	const __be32 *addr_p;
429 	u64 max_size, address;
430 	unsigned int flags;
431 	void __iomem *mem;
432 
433 	addr_p = of_get_pci_address(of_node, bar_no, &max_size, &flags);
434 	if (!addr_p)
435 		addr_p = of_get_address(of_node, bar_no, &max_size, &flags);
436 	if (!addr_p)
437 		return IOMEM_ERR_PTR(-ENODEV);
438 
439 	if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
440 		return IOMEM_ERR_PTR(-ENODEV);
441 
442 	if ((offset + size) >= max_size)
443 		return IOMEM_ERR_PTR(-ENODEV);
444 
445 	address = of_translate_address(of_node, addr_p);
446 	if (address == OF_BAD_ADDR)
447 		return IOMEM_ERR_PTR(-ENODEV);
448 
449 	mem = devm_ioremap(dev->dev, address + offset, size);
450 	if (!mem)
451 		return IOMEM_ERR_PTR(-ENOMEM);
452 
453 	return mem;
454 }
455 
456 static void __iomem *ofdrm_mach64_cmap_ioremap(struct ofdrm_device *odev,
457 					       struct device_node *of_node,
458 					       u64 fb_base)
459 {
460 	struct drm_device *dev = &odev->dev;
461 	u64 address;
462 	void __iomem *cmap_base;
463 
464 	address = fb_base & 0xff000000ul;
465 	address += 0x7ff000;
466 
467 	cmap_base = devm_ioremap(dev->dev, address, 0x1000);
468 	if (!cmap_base)
469 		return IOMEM_ERR_PTR(-ENOMEM);
470 
471 	return cmap_base;
472 }
473 
474 static void ofdrm_mach64_cmap_write(struct ofdrm_device *odev, unsigned char index,
475 				    unsigned char r, unsigned char g, unsigned char b)
476 {
477 	void __iomem *addr = odev->cmap_base + 0xcc0;
478 	void __iomem *data = odev->cmap_base + 0xcc0 + 1;
479 
480 	writeb(index, addr);
481 	writeb(r, data);
482 	writeb(g, data);
483 	writeb(b, data);
484 }
485 
486 static void __iomem *ofdrm_rage128_cmap_ioremap(struct ofdrm_device *odev,
487 						struct device_node *of_node,
488 						u64 fb_base)
489 {
490 	return get_cmap_address_of(odev, of_node, 2, 0, 0x1fff);
491 }
492 
493 static void ofdrm_rage128_cmap_write(struct ofdrm_device *odev, unsigned char index,
494 				     unsigned char r, unsigned char g, unsigned char b)
495 {
496 	void __iomem *addr = odev->cmap_base + 0xb0;
497 	void __iomem *data = odev->cmap_base + 0xb4;
498 	u32 color = (r << 16) | (g << 8) | b;
499 
500 	writeb(index, addr);
501 	writel(color, data);
502 }
503 
504 static void __iomem *ofdrm_rage_m3a_cmap_ioremap(struct ofdrm_device *odev,
505 						 struct device_node *of_node,
506 						 u64 fb_base)
507 {
508 	return get_cmap_address_of(odev, of_node, 2, 0, 0x1fff);
509 }
510 
511 static void ofdrm_rage_m3a_cmap_write(struct ofdrm_device *odev, unsigned char index,
512 				      unsigned char r, unsigned char g, unsigned char b)
513 {
514 	void __iomem *dac_ctl = odev->cmap_base + 0x58;
515 	void __iomem *addr = odev->cmap_base + 0xb0;
516 	void __iomem *data = odev->cmap_base + 0xb4;
517 	u32 color = (r << 16) | (g << 8) | b;
518 	u32 val;
519 
520 	/* Clear PALETTE_ACCESS_CNTL in DAC_CNTL */
521 	val = readl(dac_ctl);
522 	val &= ~0x20;
523 	writel(val, dac_ctl);
524 
525 	/* Set color at palette index */
526 	writeb(index, addr);
527 	writel(color, data);
528 }
529 
530 static void __iomem *ofdrm_rage_m3b_cmap_ioremap(struct ofdrm_device *odev,
531 						 struct device_node *of_node,
532 						 u64 fb_base)
533 {
534 	return get_cmap_address_of(odev, of_node, 2, 0, 0x1fff);
535 }
536 
537 static void ofdrm_rage_m3b_cmap_write(struct ofdrm_device *odev, unsigned char index,
538 				      unsigned char r, unsigned char g, unsigned char b)
539 {
540 	void __iomem *dac_ctl = odev->cmap_base + 0x58;
541 	void __iomem *addr = odev->cmap_base + 0xb0;
542 	void __iomem *data = odev->cmap_base + 0xb4;
543 	u32 color = (r << 16) | (g << 8) | b;
544 	u32 val;
545 
546 	/* Set PALETTE_ACCESS_CNTL in DAC_CNTL */
547 	val = readl(dac_ctl);
548 	val |= 0x20;
549 	writel(val, dac_ctl);
550 
551 	/* Set color at palette index */
552 	writeb(index, addr);
553 	writel(color, data);
554 }
555 
556 static void __iomem *ofdrm_radeon_cmap_ioremap(struct ofdrm_device *odev,
557 					       struct device_node *of_node,
558 					       u64 fb_base)
559 {
560 	return get_cmap_address_of(odev, of_node, 1, 0, 0x1fff);
561 }
562 
563 static void __iomem *ofdrm_gxt2000_cmap_ioremap(struct ofdrm_device *odev,
564 						struct device_node *of_node,
565 						u64 fb_base)
566 {
567 	return get_cmap_address_of(odev, of_node, 0, 0x6000, 0x1000);
568 }
569 
570 static void ofdrm_gxt2000_cmap_write(struct ofdrm_device *odev, unsigned char index,
571 				     unsigned char r, unsigned char g, unsigned char b)
572 {
573 	void __iomem *data = ((unsigned int __iomem *)odev->cmap_base) + index;
574 	u32 color = (r << 16) | (g << 8) | b;
575 
576 	writel(color, data);
577 }
578 
579 static void __iomem *ofdrm_avivo_cmap_ioremap(struct ofdrm_device *odev,
580 					      struct device_node *of_node,
581 					      u64 fb_base)
582 {
583 	struct device_node *of_parent;
584 	void __iomem *cmap_base;
585 
586 	of_parent = of_get_parent(of_node);
587 	cmap_base = get_cmap_address_of(odev, of_parent, 0, 0, 0x10000);
588 	of_node_put(of_parent);
589 
590 	return cmap_base;
591 }
592 
593 static void ofdrm_avivo_cmap_write(struct ofdrm_device *odev, unsigned char index,
594 				   unsigned char r, unsigned char g, unsigned char b)
595 {
596 	void __iomem *lutsel = odev->cmap_base + AVIVO_DC_LUT_RW_SELECT;
597 	void __iomem *addr = odev->cmap_base + AVIVO_DC_LUT_RW_INDEX;
598 	void __iomem *data = odev->cmap_base + AVIVO_DC_LUT_30_COLOR;
599 	u32 color = (r << 22) | (g << 12) | (b << 2);
600 
601 	/* Write to both LUTs for now */
602 
603 	writel(1, lutsel);
604 	writeb(index, addr);
605 	writel(color, data);
606 
607 	writel(0, lutsel);
608 	writeb(index, addr);
609 	writel(color, data);
610 }
611 
612 static void __iomem *ofdrm_qemu_cmap_ioremap(struct ofdrm_device *odev,
613 					     struct device_node *of_node,
614 					     u64 fb_base)
615 {
616 	static const __be32 io_of_addr[3] = {
617 		cpu_to_be32(0x01000000),
618 		cpu_to_be32(0x00),
619 		cpu_to_be32(0x00),
620 	};
621 
622 	struct drm_device *dev = &odev->dev;
623 	u64 address;
624 	void __iomem *cmap_base;
625 
626 	address = of_translate_address(of_node, io_of_addr);
627 	if (address == OF_BAD_ADDR)
628 		return IOMEM_ERR_PTR(-ENODEV);
629 
630 	cmap_base = devm_ioremap(dev->dev, address + 0x3c8, 2);
631 	if (!cmap_base)
632 		return IOMEM_ERR_PTR(-ENOMEM);
633 
634 	return cmap_base;
635 }
636 
637 static void ofdrm_qemu_cmap_write(struct ofdrm_device *odev, unsigned char index,
638 				  unsigned char r, unsigned char g, unsigned char b)
639 {
640 	void __iomem *addr = odev->cmap_base;
641 	void __iomem *data = odev->cmap_base + 1;
642 
643 	writeb(index, addr);
644 	writeb(r, data);
645 	writeb(g, data);
646 	writeb(b, data);
647 }
648 
649 static void ofdrm_device_set_gamma_linear(struct ofdrm_device *odev,
650 					  const struct drm_format_info *format)
651 {
652 	struct drm_device *dev = &odev->dev;
653 	int i;
654 
655 	switch (format->format) {
656 	case DRM_FORMAT_RGB565:
657 	case DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN:
658 		/* Use better interpolation, to take 32 values from 0 to 255 */
659 		for (i = 0; i < OFDRM_GAMMA_LUT_SIZE / 8; i++) {
660 			unsigned char r = i * 8 + i / 4;
661 			unsigned char g = i * 4 + i / 16;
662 			unsigned char b = i * 8 + i / 4;
663 
664 			odev->funcs->cmap_write(odev, i, r, g, b);
665 		}
666 		/* Green has one more bit, so add padding with 0 for red and blue. */
667 		for (i = OFDRM_GAMMA_LUT_SIZE / 8; i < OFDRM_GAMMA_LUT_SIZE / 4; i++) {
668 			unsigned char r = 0;
669 			unsigned char g = i * 4 + i / 16;
670 			unsigned char b = 0;
671 
672 			odev->funcs->cmap_write(odev, i, r, g, b);
673 		}
674 		break;
675 	case DRM_FORMAT_XRGB8888:
676 	case DRM_FORMAT_BGRX8888:
677 		for (i = 0; i < OFDRM_GAMMA_LUT_SIZE; i++)
678 			odev->funcs->cmap_write(odev, i, i, i, i);
679 		break;
680 	default:
681 		drm_warn_once(dev, "Unsupported format %p4cc for gamma correction\n",
682 			      &format->format);
683 		break;
684 	}
685 }
686 
687 static void ofdrm_device_set_gamma(struct ofdrm_device *odev,
688 				   const struct drm_format_info *format,
689 				   struct drm_color_lut *lut)
690 {
691 	struct drm_device *dev = &odev->dev;
692 	int i;
693 
694 	switch (format->format) {
695 	case DRM_FORMAT_RGB565:
696 	case DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN:
697 		/* Use better interpolation, to take 32 values from lut[0] to lut[255] */
698 		for (i = 0; i < OFDRM_GAMMA_LUT_SIZE / 8; i++) {
699 			unsigned char r = lut[i * 8 + i / 4].red >> 8;
700 			unsigned char g = lut[i * 4 + i / 16].green >> 8;
701 			unsigned char b = lut[i * 8 + i / 4].blue >> 8;
702 
703 			odev->funcs->cmap_write(odev, i, r, g, b);
704 		}
705 		/* Green has one more bit, so add padding with 0 for red and blue. */
706 		for (i = OFDRM_GAMMA_LUT_SIZE / 8; i < OFDRM_GAMMA_LUT_SIZE / 4; i++) {
707 			unsigned char r = 0;
708 			unsigned char g = lut[i * 4 + i / 16].green >> 8;
709 			unsigned char b = 0;
710 
711 			odev->funcs->cmap_write(odev, i, r, g, b);
712 		}
713 		break;
714 	case DRM_FORMAT_XRGB8888:
715 	case DRM_FORMAT_BGRX8888:
716 		for (i = 0; i < OFDRM_GAMMA_LUT_SIZE; i++) {
717 			unsigned char r = lut[i].red >> 8;
718 			unsigned char g = lut[i].green >> 8;
719 			unsigned char b = lut[i].blue >> 8;
720 
721 			odev->funcs->cmap_write(odev, i, r, g, b);
722 		}
723 		break;
724 	default:
725 		drm_warn_once(dev, "Unsupported format %p4cc for gamma correction\n",
726 			      &format->format);
727 		break;
728 	}
729 }
730 
731 /*
732  * Modesetting
733  */
734 
735 struct ofdrm_crtc_state {
736 	struct drm_crtc_state base;
737 
738 	/* Primary-plane format; required for color mgmt. */
739 	const struct drm_format_info *format;
740 };
741 
742 static struct ofdrm_crtc_state *to_ofdrm_crtc_state(struct drm_crtc_state *base)
743 {
744 	return container_of(base, struct ofdrm_crtc_state, base);
745 }
746 
747 static void ofdrm_crtc_state_destroy(struct ofdrm_crtc_state *ofdrm_crtc_state)
748 {
749 	__drm_atomic_helper_crtc_destroy_state(&ofdrm_crtc_state->base);
750 	kfree(ofdrm_crtc_state);
751 }
752 
753 static const uint64_t ofdrm_primary_plane_format_modifiers[] = {
754 	DRM_FORMAT_MOD_LINEAR,
755 	DRM_FORMAT_MOD_INVALID
756 };
757 
758 static int ofdrm_primary_plane_helper_atomic_check(struct drm_plane *plane,
759 						   struct drm_atomic_state *new_state)
760 {
761 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(new_state, plane);
762 	struct drm_framebuffer *new_fb = new_plane_state->fb;
763 	struct drm_crtc *new_crtc = new_plane_state->crtc;
764 	struct drm_crtc_state *new_crtc_state = NULL;
765 	struct ofdrm_crtc_state *new_ofdrm_crtc_state;
766 	int ret;
767 
768 	if (new_crtc)
769 		new_crtc_state = drm_atomic_get_new_crtc_state(new_state, new_plane_state->crtc);
770 
771 	ret = drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
772 						  DRM_PLANE_NO_SCALING,
773 						  DRM_PLANE_NO_SCALING,
774 						  false, false);
775 	if (ret)
776 		return ret;
777 	else if (!new_plane_state->visible)
778 		return 0;
779 
780 	new_crtc_state = drm_atomic_get_new_crtc_state(new_state, new_plane_state->crtc);
781 
782 	new_ofdrm_crtc_state = to_ofdrm_crtc_state(new_crtc_state);
783 	new_ofdrm_crtc_state->format = new_fb->format;
784 
785 	return 0;
786 }
787 
788 static void ofdrm_primary_plane_helper_atomic_update(struct drm_plane *plane,
789 						     struct drm_atomic_state *state)
790 {
791 	struct drm_device *dev = plane->dev;
792 	struct ofdrm_device *odev = ofdrm_device_of_dev(dev);
793 	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
794 	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
795 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
796 	struct drm_framebuffer *fb = plane_state->fb;
797 	unsigned int dst_pitch = odev->pitch;
798 	const struct drm_format_info *dst_format = odev->format;
799 	struct drm_atomic_helper_damage_iter iter;
800 	struct drm_rect damage;
801 	int ret, idx;
802 
803 	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
804 	if (ret)
805 		return;
806 
807 	if (!drm_dev_enter(dev, &idx))
808 		goto out_drm_gem_fb_end_cpu_access;
809 
810 	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
811 	drm_atomic_for_each_plane_damage(&iter, &damage) {
812 		struct iosys_map dst = odev->screen_base;
813 		struct drm_rect dst_clip = plane_state->dst;
814 
815 		if (!drm_rect_intersect(&dst_clip, &damage))
816 			continue;
817 
818 		iosys_map_incr(&dst, drm_fb_clip_offset(dst_pitch, dst_format, &dst_clip));
819 		drm_fb_blit(&dst, &dst_pitch, dst_format->format, shadow_plane_state->data, fb,
820 			    &damage);
821 	}
822 
823 	drm_dev_exit(idx);
824 out_drm_gem_fb_end_cpu_access:
825 	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
826 }
827 
828 static void ofdrm_primary_plane_helper_atomic_disable(struct drm_plane *plane,
829 						      struct drm_atomic_state *state)
830 {
831 	struct drm_device *dev = plane->dev;
832 	struct ofdrm_device *odev = ofdrm_device_of_dev(dev);
833 	struct iosys_map dst = odev->screen_base;
834 	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
835 	void __iomem *dst_vmap = dst.vaddr_iomem; /* TODO: Use mapping abstraction */
836 	unsigned int dst_pitch = odev->pitch;
837 	const struct drm_format_info *dst_format = odev->format;
838 	struct drm_rect dst_clip;
839 	unsigned long lines, linepixels, i;
840 	int idx;
841 
842 	drm_rect_init(&dst_clip,
843 		      plane_state->src_x >> 16, plane_state->src_y >> 16,
844 		      plane_state->src_w >> 16, plane_state->src_h >> 16);
845 
846 	lines = drm_rect_height(&dst_clip);
847 	linepixels = drm_rect_width(&dst_clip);
848 
849 	if (!drm_dev_enter(dev, &idx))
850 		return;
851 
852 	/* Clear buffer to black if disabled */
853 	dst_vmap += drm_fb_clip_offset(dst_pitch, dst_format, &dst_clip);
854 	for (i = 0; i < lines; ++i) {
855 		memset_io(dst_vmap, 0, linepixels * dst_format->cpp[0]);
856 		dst_vmap += dst_pitch;
857 	}
858 
859 	drm_dev_exit(idx);
860 }
861 
862 static const struct drm_plane_helper_funcs ofdrm_primary_plane_helper_funcs = {
863 	DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
864 	.atomic_check = ofdrm_primary_plane_helper_atomic_check,
865 	.atomic_update = ofdrm_primary_plane_helper_atomic_update,
866 	.atomic_disable = ofdrm_primary_plane_helper_atomic_disable,
867 };
868 
869 static const struct drm_plane_funcs ofdrm_primary_plane_funcs = {
870 	.update_plane = drm_atomic_helper_update_plane,
871 	.disable_plane = drm_atomic_helper_disable_plane,
872 	.destroy = drm_plane_cleanup,
873 	DRM_GEM_SHADOW_PLANE_FUNCS,
874 };
875 
876 static enum drm_mode_status ofdrm_crtc_helper_mode_valid(struct drm_crtc *crtc,
877 							 const struct drm_display_mode *mode)
878 {
879 	struct ofdrm_device *odev = ofdrm_device_of_dev(crtc->dev);
880 
881 	return drm_crtc_helper_mode_valid_fixed(crtc, mode, &odev->mode);
882 }
883 
884 static int ofdrm_crtc_helper_atomic_check(struct drm_crtc *crtc,
885 					  struct drm_atomic_state *new_state)
886 {
887 	static const size_t gamma_lut_length = OFDRM_GAMMA_LUT_SIZE * sizeof(struct drm_color_lut);
888 
889 	struct drm_device *dev = crtc->dev;
890 	struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(new_state, crtc);
891 	int ret;
892 
893 	if (!new_crtc_state->enable)
894 		return 0;
895 
896 	ret = drm_atomic_helper_check_crtc_primary_plane(new_crtc_state);
897 	if (ret)
898 		return ret;
899 
900 	if (new_crtc_state->color_mgmt_changed) {
901 		struct drm_property_blob *gamma_lut = new_crtc_state->gamma_lut;
902 
903 		if (gamma_lut && (gamma_lut->length != gamma_lut_length)) {
904 			drm_dbg(dev, "Incorrect gamma_lut length %zu\n", gamma_lut->length);
905 			return -EINVAL;
906 		}
907 	}
908 
909 	return 0;
910 }
911 
912 static void ofdrm_crtc_helper_atomic_flush(struct drm_crtc *crtc, struct drm_atomic_state *state)
913 {
914 	struct ofdrm_device *odev = ofdrm_device_of_dev(crtc->dev);
915 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
916 	struct ofdrm_crtc_state *ofdrm_crtc_state = to_ofdrm_crtc_state(crtc_state);
917 
918 	if (crtc_state->enable && crtc_state->color_mgmt_changed) {
919 		const struct drm_format_info *format = ofdrm_crtc_state->format;
920 
921 		if (crtc_state->gamma_lut)
922 			ofdrm_device_set_gamma(odev, format, crtc_state->gamma_lut->data);
923 		else
924 			ofdrm_device_set_gamma_linear(odev, format);
925 	}
926 }
927 
928 /*
929  * The CRTC is always enabled. Screen updates are performed by
930  * the primary plane's atomic_update function. Disabling clears
931  * the screen in the primary plane's atomic_disable function.
932  */
933 static const struct drm_crtc_helper_funcs ofdrm_crtc_helper_funcs = {
934 	.mode_valid = ofdrm_crtc_helper_mode_valid,
935 	.atomic_check = ofdrm_crtc_helper_atomic_check,
936 	.atomic_flush = ofdrm_crtc_helper_atomic_flush,
937 };
938 
939 static void ofdrm_crtc_reset(struct drm_crtc *crtc)
940 {
941 	struct ofdrm_crtc_state *ofdrm_crtc_state =
942 		kzalloc(sizeof(*ofdrm_crtc_state), GFP_KERNEL);
943 
944 	if (crtc->state)
945 		ofdrm_crtc_state_destroy(to_ofdrm_crtc_state(crtc->state));
946 
947 	if (ofdrm_crtc_state)
948 		__drm_atomic_helper_crtc_reset(crtc, &ofdrm_crtc_state->base);
949 	else
950 		__drm_atomic_helper_crtc_reset(crtc, NULL);
951 }
952 
953 static struct drm_crtc_state *ofdrm_crtc_atomic_duplicate_state(struct drm_crtc *crtc)
954 {
955 	struct drm_device *dev = crtc->dev;
956 	struct drm_crtc_state *crtc_state = crtc->state;
957 	struct ofdrm_crtc_state *new_ofdrm_crtc_state;
958 	struct ofdrm_crtc_state *ofdrm_crtc_state;
959 
960 	if (drm_WARN_ON(dev, !crtc_state))
961 		return NULL;
962 
963 	new_ofdrm_crtc_state = kzalloc(sizeof(*new_ofdrm_crtc_state), GFP_KERNEL);
964 	if (!new_ofdrm_crtc_state)
965 		return NULL;
966 
967 	ofdrm_crtc_state = to_ofdrm_crtc_state(crtc_state);
968 
969 	__drm_atomic_helper_crtc_duplicate_state(crtc, &new_ofdrm_crtc_state->base);
970 	new_ofdrm_crtc_state->format = ofdrm_crtc_state->format;
971 
972 	return &new_ofdrm_crtc_state->base;
973 }
974 
975 static void ofdrm_crtc_atomic_destroy_state(struct drm_crtc *crtc,
976 					    struct drm_crtc_state *crtc_state)
977 {
978 	ofdrm_crtc_state_destroy(to_ofdrm_crtc_state(crtc_state));
979 }
980 
981 static const struct drm_crtc_funcs ofdrm_crtc_funcs = {
982 	.reset = ofdrm_crtc_reset,
983 	.destroy = drm_crtc_cleanup,
984 	.set_config = drm_atomic_helper_set_config,
985 	.page_flip = drm_atomic_helper_page_flip,
986 	.atomic_duplicate_state = ofdrm_crtc_atomic_duplicate_state,
987 	.atomic_destroy_state = ofdrm_crtc_atomic_destroy_state,
988 };
989 
990 static int ofdrm_connector_helper_get_modes(struct drm_connector *connector)
991 {
992 	struct ofdrm_device *odev = ofdrm_device_of_dev(connector->dev);
993 
994 	return drm_connector_helper_get_modes_fixed(connector, &odev->mode);
995 }
996 
997 static const struct drm_connector_helper_funcs ofdrm_connector_helper_funcs = {
998 	.get_modes = ofdrm_connector_helper_get_modes,
999 };
1000 
1001 static const struct drm_connector_funcs ofdrm_connector_funcs = {
1002 	.reset = drm_atomic_helper_connector_reset,
1003 	.fill_modes = drm_helper_probe_single_connector_modes,
1004 	.destroy = drm_connector_cleanup,
1005 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
1006 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
1007 };
1008 
1009 static const struct drm_mode_config_funcs ofdrm_mode_config_funcs = {
1010 	.fb_create = drm_gem_fb_create_with_dirty,
1011 	.atomic_check = drm_atomic_helper_check,
1012 	.atomic_commit = drm_atomic_helper_commit,
1013 };
1014 
1015 /*
1016  * Init / Cleanup
1017  */
1018 
1019 static const struct ofdrm_device_funcs ofdrm_unknown_device_funcs = {
1020 };
1021 
1022 static const struct ofdrm_device_funcs ofdrm_mach64_device_funcs = {
1023 	.cmap_ioremap = ofdrm_mach64_cmap_ioremap,
1024 	.cmap_write = ofdrm_mach64_cmap_write,
1025 };
1026 
1027 static const struct ofdrm_device_funcs ofdrm_rage128_device_funcs = {
1028 	.cmap_ioremap = ofdrm_rage128_cmap_ioremap,
1029 	.cmap_write = ofdrm_rage128_cmap_write,
1030 };
1031 
1032 static const struct ofdrm_device_funcs ofdrm_rage_m3a_device_funcs = {
1033 	.cmap_ioremap = ofdrm_rage_m3a_cmap_ioremap,
1034 	.cmap_write = ofdrm_rage_m3a_cmap_write,
1035 };
1036 
1037 static const struct ofdrm_device_funcs ofdrm_rage_m3b_device_funcs = {
1038 	.cmap_ioremap = ofdrm_rage_m3b_cmap_ioremap,
1039 	.cmap_write = ofdrm_rage_m3b_cmap_write,
1040 };
1041 
1042 static const struct ofdrm_device_funcs ofdrm_radeon_device_funcs = {
1043 	.cmap_ioremap = ofdrm_radeon_cmap_ioremap,
1044 	.cmap_write = ofdrm_rage128_cmap_write, /* same as Rage128 */
1045 };
1046 
1047 static const struct ofdrm_device_funcs ofdrm_gxt2000_device_funcs = {
1048 	.cmap_ioremap = ofdrm_gxt2000_cmap_ioremap,
1049 	.cmap_write = ofdrm_gxt2000_cmap_write,
1050 };
1051 
1052 static const struct ofdrm_device_funcs ofdrm_avivo_device_funcs = {
1053 	.cmap_ioremap = ofdrm_avivo_cmap_ioremap,
1054 	.cmap_write = ofdrm_avivo_cmap_write,
1055 };
1056 
1057 static const struct ofdrm_device_funcs ofdrm_qemu_device_funcs = {
1058 	.cmap_ioremap = ofdrm_qemu_cmap_ioremap,
1059 	.cmap_write = ofdrm_qemu_cmap_write,
1060 };
1061 
1062 static struct drm_display_mode ofdrm_mode(unsigned int width, unsigned int height)
1063 {
1064 	/*
1065 	 * Assume a monitor resolution of 96 dpi to
1066 	 * get a somewhat reasonable screen size.
1067 	 */
1068 	const struct drm_display_mode mode = {
1069 		DRM_MODE_INIT(60, width, height,
1070 			      DRM_MODE_RES_MM(width, 96ul),
1071 			      DRM_MODE_RES_MM(height, 96ul))
1072 	};
1073 
1074 	return mode;
1075 }
1076 
1077 static struct ofdrm_device *ofdrm_device_create(struct drm_driver *drv,
1078 						struct platform_device *pdev)
1079 {
1080 	struct device_node *of_node = pdev->dev.of_node;
1081 	struct ofdrm_device *odev;
1082 	struct drm_device *dev;
1083 	enum ofdrm_model model;
1084 	bool big_endian;
1085 	int width, height, depth, linebytes;
1086 	const struct drm_format_info *format;
1087 	u64 address;
1088 	resource_size_t fb_size, fb_base, fb_pgbase, fb_pgsize;
1089 	struct resource *res, *mem;
1090 	void __iomem *screen_base;
1091 	struct drm_plane *primary_plane;
1092 	struct drm_crtc *crtc;
1093 	struct drm_encoder *encoder;
1094 	struct drm_connector *connector;
1095 	unsigned long max_width, max_height;
1096 	size_t nformats;
1097 	int ret;
1098 
1099 	odev = devm_drm_dev_alloc(&pdev->dev, drv, struct ofdrm_device, dev);
1100 	if (IS_ERR(odev))
1101 		return ERR_CAST(odev);
1102 	dev = &odev->dev;
1103 	platform_set_drvdata(pdev, dev);
1104 
1105 	ret = ofdrm_device_init_pci(odev);
1106 	if (ret)
1107 		return ERR_PTR(ret);
1108 
1109 	/*
1110 	 * OF display-node settings
1111 	 */
1112 
1113 	model = display_get_model_of(dev, of_node);
1114 	drm_dbg(dev, "detected model %d\n", model);
1115 
1116 	switch (model) {
1117 	case OFDRM_MODEL_UNKNOWN:
1118 		odev->funcs = &ofdrm_unknown_device_funcs;
1119 		break;
1120 	case OFDRM_MODEL_MACH64:
1121 		odev->funcs = &ofdrm_mach64_device_funcs;
1122 		break;
1123 	case OFDRM_MODEL_RAGE128:
1124 		odev->funcs = &ofdrm_rage128_device_funcs;
1125 		break;
1126 	case OFDRM_MODEL_RAGE_M3A:
1127 		odev->funcs = &ofdrm_rage_m3a_device_funcs;
1128 		break;
1129 	case OFDRM_MODEL_RAGE_M3B:
1130 		odev->funcs = &ofdrm_rage_m3b_device_funcs;
1131 		break;
1132 	case OFDRM_MODEL_RADEON:
1133 		odev->funcs = &ofdrm_radeon_device_funcs;
1134 		break;
1135 	case OFDRM_MODEL_GXT2000:
1136 		odev->funcs = &ofdrm_gxt2000_device_funcs;
1137 		break;
1138 	case OFDRM_MODEL_AVIVO:
1139 		odev->funcs = &ofdrm_avivo_device_funcs;
1140 		break;
1141 	case OFDRM_MODEL_QEMU:
1142 		odev->funcs = &ofdrm_qemu_device_funcs;
1143 		break;
1144 	}
1145 
1146 	big_endian = display_get_big_endian_of(dev, of_node);
1147 
1148 	width = display_get_width_of(dev, of_node);
1149 	if (width < 0)
1150 		return ERR_PTR(width);
1151 	height = display_get_height_of(dev, of_node);
1152 	if (height < 0)
1153 		return ERR_PTR(height);
1154 	depth = display_get_depth_of(dev, of_node);
1155 	if (depth < 0)
1156 		return ERR_PTR(depth);
1157 	linebytes = display_get_linebytes_of(dev, of_node);
1158 	if (linebytes < 0)
1159 		return ERR_PTR(linebytes);
1160 
1161 	format = display_get_validated_format(dev, depth, big_endian);
1162 	if (IS_ERR(format))
1163 		return ERR_CAST(format);
1164 	if (!linebytes) {
1165 		linebytes = drm_format_info_min_pitch(format, 0, width);
1166 		if (drm_WARN_ON(dev, !linebytes))
1167 			return ERR_PTR(-EINVAL);
1168 	}
1169 
1170 	fb_size = linebytes * height;
1171 
1172 	/*
1173 	 * Try to figure out the address of the framebuffer. Unfortunately, Open
1174 	 * Firmware doesn't provide a standard way to do so. All we can do is a
1175 	 * dodgy heuristic that happens to work in practice.
1176 	 *
1177 	 * On most machines, the "address" property contains what we need, though
1178 	 * not on Matrox cards found in IBM machines. What appears to give good
1179 	 * results is to go through the PCI ranges and pick one that encloses the
1180 	 * "address" property. If none match, we pick the largest.
1181 	 */
1182 	address = display_get_address_of(dev, of_node);
1183 	if (address != OF_BAD_ADDR) {
1184 		struct resource fb_res = DEFINE_RES_MEM(address, fb_size);
1185 
1186 		res = ofdrm_find_fb_resource(odev, &fb_res);
1187 		if (!res)
1188 			return ERR_PTR(-EINVAL);
1189 		if (resource_contains(res, &fb_res))
1190 			fb_base = address;
1191 		else
1192 			fb_base = res->start;
1193 	} else {
1194 		struct resource fb_res = DEFINE_RES_MEM(0u, fb_size);
1195 
1196 		res = ofdrm_find_fb_resource(odev, &fb_res);
1197 		if (!res)
1198 			return ERR_PTR(-EINVAL);
1199 		fb_base = res->start;
1200 	}
1201 
1202 	/*
1203 	 * I/O resources
1204 	 */
1205 
1206 	fb_pgbase = round_down(fb_base, PAGE_SIZE);
1207 	fb_pgsize = fb_base - fb_pgbase + round_up(fb_size, PAGE_SIZE);
1208 
1209 	ret = devm_aperture_acquire_from_firmware(dev, fb_pgbase, fb_pgsize);
1210 	if (ret) {
1211 		drm_err(dev, "could not acquire memory range %pr: error %d\n", &res, ret);
1212 		return ERR_PTR(ret);
1213 	}
1214 
1215 	mem = devm_request_mem_region(&pdev->dev, fb_pgbase, fb_pgsize, drv->name);
1216 	if (!mem) {
1217 		drm_warn(dev, "could not acquire memory region %pr\n", &res);
1218 		return ERR_PTR(-ENOMEM);
1219 	}
1220 
1221 	screen_base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
1222 	if (!screen_base)
1223 		return ERR_PTR(-ENOMEM);
1224 
1225 	if (odev->funcs->cmap_ioremap) {
1226 		void __iomem *cmap_base = odev->funcs->cmap_ioremap(odev, of_node, fb_base);
1227 
1228 		if (IS_ERR(cmap_base)) {
1229 			/* Don't fail; continue without colormap */
1230 			drm_warn(dev, "could not find colormap: error %ld\n", PTR_ERR(cmap_base));
1231 		} else {
1232 			odev->cmap_base = cmap_base;
1233 		}
1234 	}
1235 
1236 	/*
1237 	 * Firmware framebuffer
1238 	 */
1239 
1240 	iosys_map_set_vaddr_iomem(&odev->screen_base, screen_base);
1241 	odev->mode = ofdrm_mode(width, height);
1242 	odev->format = format;
1243 	odev->pitch = linebytes;
1244 
1245 	drm_dbg(dev, "display mode={" DRM_MODE_FMT "}\n", DRM_MODE_ARG(&odev->mode));
1246 	drm_dbg(dev, "framebuffer format=%p4cc, size=%dx%d, linebytes=%d byte\n",
1247 		&format->format, width, height, linebytes);
1248 
1249 	/*
1250 	 * Mode-setting pipeline
1251 	 */
1252 
1253 	ret = drmm_mode_config_init(dev);
1254 	if (ret)
1255 		return ERR_PTR(ret);
1256 
1257 	max_width = max_t(unsigned long, width, DRM_SHADOW_PLANE_MAX_WIDTH);
1258 	max_height = max_t(unsigned long, height, DRM_SHADOW_PLANE_MAX_HEIGHT);
1259 
1260 	dev->mode_config.min_width = width;
1261 	dev->mode_config.max_width = max_width;
1262 	dev->mode_config.min_height = height;
1263 	dev->mode_config.max_height = max_height;
1264 	dev->mode_config.funcs = &ofdrm_mode_config_funcs;
1265 	dev->mode_config.preferred_depth = format->depth;
1266 	dev->mode_config.quirk_addfb_prefer_host_byte_order = true;
1267 
1268 	/* Primary plane */
1269 
1270 	nformats = drm_fb_build_fourcc_list(dev, &format->format, 1,
1271 					    odev->formats, ARRAY_SIZE(odev->formats));
1272 
1273 	primary_plane = &odev->primary_plane;
1274 	ret = drm_universal_plane_init(dev, primary_plane, 0, &ofdrm_primary_plane_funcs,
1275 				       odev->formats, nformats,
1276 				       ofdrm_primary_plane_format_modifiers,
1277 				       DRM_PLANE_TYPE_PRIMARY, NULL);
1278 	if (ret)
1279 		return ERR_PTR(ret);
1280 	drm_plane_helper_add(primary_plane, &ofdrm_primary_plane_helper_funcs);
1281 	drm_plane_enable_fb_damage_clips(primary_plane);
1282 
1283 	/* CRTC */
1284 
1285 	crtc = &odev->crtc;
1286 	ret = drm_crtc_init_with_planes(dev, crtc, primary_plane, NULL,
1287 					&ofdrm_crtc_funcs, NULL);
1288 	if (ret)
1289 		return ERR_PTR(ret);
1290 	drm_crtc_helper_add(crtc, &ofdrm_crtc_helper_funcs);
1291 
1292 	if (odev->cmap_base) {
1293 		drm_mode_crtc_set_gamma_size(crtc, OFDRM_GAMMA_LUT_SIZE);
1294 		drm_crtc_enable_color_mgmt(crtc, 0, false, OFDRM_GAMMA_LUT_SIZE);
1295 	}
1296 
1297 	/* Encoder */
1298 
1299 	encoder = &odev->encoder;
1300 	ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE);
1301 	if (ret)
1302 		return ERR_PTR(ret);
1303 	encoder->possible_crtcs = drm_crtc_mask(crtc);
1304 
1305 	/* Connector */
1306 
1307 	connector = &odev->connector;
1308 	ret = drm_connector_init(dev, connector, &ofdrm_connector_funcs,
1309 				 DRM_MODE_CONNECTOR_Unknown);
1310 	if (ret)
1311 		return ERR_PTR(ret);
1312 	drm_connector_helper_add(connector, &ofdrm_connector_helper_funcs);
1313 	drm_connector_set_panel_orientation_with_quirk(connector,
1314 						       DRM_MODE_PANEL_ORIENTATION_UNKNOWN,
1315 						       width, height);
1316 
1317 	ret = drm_connector_attach_encoder(connector, encoder);
1318 	if (ret)
1319 		return ERR_PTR(ret);
1320 
1321 	drm_mode_config_reset(dev);
1322 
1323 	return odev;
1324 }
1325 
1326 /*
1327  * DRM driver
1328  */
1329 
1330 DEFINE_DRM_GEM_FOPS(ofdrm_fops);
1331 
1332 static struct drm_driver ofdrm_driver = {
1333 	DRM_GEM_SHMEM_DRIVER_OPS,
1334 	.name			= DRIVER_NAME,
1335 	.desc			= DRIVER_DESC,
1336 	.date			= DRIVER_DATE,
1337 	.major			= DRIVER_MAJOR,
1338 	.minor			= DRIVER_MINOR,
1339 	.driver_features	= DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
1340 	.fops			= &ofdrm_fops,
1341 };
1342 
1343 /*
1344  * Platform driver
1345  */
1346 
1347 static int ofdrm_probe(struct platform_device *pdev)
1348 {
1349 	struct ofdrm_device *odev;
1350 	struct drm_device *dev;
1351 	unsigned int color_mode;
1352 	int ret;
1353 
1354 	odev = ofdrm_device_create(&ofdrm_driver, pdev);
1355 	if (IS_ERR(odev))
1356 		return PTR_ERR(odev);
1357 	dev = &odev->dev;
1358 
1359 	ret = drm_dev_register(dev, 0);
1360 	if (ret)
1361 		return ret;
1362 
1363 	color_mode = drm_format_info_bpp(odev->format, 0);
1364 	if (color_mode == 16)
1365 		color_mode = odev->format->depth; // can be 15 or 16
1366 
1367 	drm_fbdev_generic_setup(dev, color_mode);
1368 
1369 	return 0;
1370 }
1371 
1372 static void ofdrm_remove(struct platform_device *pdev)
1373 {
1374 	struct drm_device *dev = platform_get_drvdata(pdev);
1375 
1376 	drm_dev_unplug(dev);
1377 }
1378 
1379 static const struct of_device_id ofdrm_of_match_display[] = {
1380 	{ .compatible = "display", },
1381 	{ },
1382 };
1383 MODULE_DEVICE_TABLE(of, ofdrm_of_match_display);
1384 
1385 static struct platform_driver ofdrm_platform_driver = {
1386 	.driver = {
1387 		.name = "of-display",
1388 		.of_match_table = ofdrm_of_match_display,
1389 	},
1390 	.probe = ofdrm_probe,
1391 	.remove_new = ofdrm_remove,
1392 };
1393 
1394 module_platform_driver(ofdrm_platform_driver);
1395 
1396 MODULE_DESCRIPTION(DRIVER_DESC);
1397 MODULE_LICENSE("GPL");
1398