xref: /linux/drivers/gpu/drm/ast/ast_main.c (revision 2fe05e1139a555ae91f00a812cb9520e7d3022ab)
1 /*
2  * Copyright 2012 Red Hat Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the
6  * "Software"), to deal in the Software without restriction, including
7  * without limitation the rights to use, copy, modify, merge, publish,
8  * distribute, sub license, and/or sell copies of the Software, and to
9  * permit persons to whom the Software is furnished to do so, subject to
10  * the following conditions:
11  *
12  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
13  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
14  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
15  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
16  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
17  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
18  * USE OR OTHER DEALINGS IN THE SOFTWARE.
19  *
20  * The above copyright notice and this permission notice (including the
21  * next paragraph) shall be included in all copies or substantial portions
22  * of the Software.
23  *
24  */
25 /*
26  * Authors: Dave Airlie <airlied@redhat.com>
27  */
28 #include <drm/drmP.h>
29 #include "ast_drv.h"
30 
31 
32 #include <drm/drm_fb_helper.h>
33 #include <drm/drm_crtc_helper.h>
34 
35 void ast_set_index_reg_mask(struct ast_private *ast,
36 			    uint32_t base, uint8_t index,
37 			    uint8_t mask, uint8_t val)
38 {
39 	u8 tmp;
40 	ast_io_write8(ast, base, index);
41 	tmp = (ast_io_read8(ast, base + 1) & mask) | val;
42 	ast_set_index_reg(ast, base, index, tmp);
43 }
44 
45 uint8_t ast_get_index_reg(struct ast_private *ast,
46 			  uint32_t base, uint8_t index)
47 {
48 	uint8_t ret;
49 	ast_io_write8(ast, base, index);
50 	ret = ast_io_read8(ast, base + 1);
51 	return ret;
52 }
53 
54 uint8_t ast_get_index_reg_mask(struct ast_private *ast,
55 			       uint32_t base, uint8_t index, uint8_t mask)
56 {
57 	uint8_t ret;
58 	ast_io_write8(ast, base, index);
59 	ret = ast_io_read8(ast, base + 1) & mask;
60 	return ret;
61 }
62 
63 static void ast_detect_config_mode(struct drm_device *dev, u32 *scu_rev)
64 {
65 	struct device_node *np = dev->pdev->dev.of_node;
66 	struct ast_private *ast = dev->dev_private;
67 	uint32_t data, jregd0, jregd1;
68 
69 	/* Defaults */
70 	ast->config_mode = ast_use_defaults;
71 	*scu_rev = 0xffffffff;
72 
73 	/* Check if we have device-tree properties */
74 	if (np && !of_property_read_u32(np, "aspeed,scu-revision-id",
75 					scu_rev)) {
76 		/* We do, disable P2A access */
77 		ast->config_mode = ast_use_dt;
78 		DRM_INFO("Using device-tree for configuration\n");
79 		return;
80 	}
81 
82 	/* Not all families have a P2A bridge */
83 	if (dev->pdev->device != PCI_CHIP_AST2000)
84 		return;
85 
86 	/*
87 	 * The BMC will set SCU 0x40 D[12] to 1 if the P2 bridge
88 	 * is disabled. We force using P2A if VGA only mode bit
89 	 * is set D[7]
90 	 */
91 	jregd0 = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd0, 0xff);
92 	jregd1 = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd1, 0xff);
93 	if (!(jregd0 & 0x80) || !(jregd1 & 0x10)) {
94 		/* Double check it's actually working */
95 		data = ast_read32(ast, 0xf004);
96 		if (data != 0xFFFFFFFF) {
97 			/* P2A works, grab silicon revision */
98 			ast->config_mode = ast_use_p2a;
99 
100 			DRM_INFO("Using P2A bridge for configuration\n");
101 
102 			/* Read SCU7c (silicon revision register) */
103 			ast_write32(ast, 0xf004, 0x1e6e0000);
104 			ast_write32(ast, 0xf000, 0x1);
105 			*scu_rev = ast_read32(ast, 0x1207c);
106 			return;
107 		}
108 	}
109 
110 	/* We have a P2A bridge but it's disabled */
111 	DRM_INFO("P2A bridge disabled, using default configuration\n");
112 }
113 
114 static int ast_detect_chip(struct drm_device *dev, bool *need_post)
115 {
116 	struct ast_private *ast = dev->dev_private;
117 	uint32_t jreg, scu_rev;
118 
119 	/*
120 	 * If VGA isn't enabled, we need to enable now or subsequent
121 	 * access to the scratch registers will fail. We also inform
122 	 * our caller that it needs to POST the chip
123 	 * (Assumption: VGA not enabled -> need to POST)
124 	 */
125 	if (!ast_is_vga_enabled(dev)) {
126 		ast_enable_vga(dev);
127 		DRM_INFO("VGA not enabled on entry, requesting chip POST\n");
128 		*need_post = true;
129 	} else
130 		*need_post = false;
131 
132 
133 	/* Enable extended register access */
134 	ast_enable_mmio(dev);
135 	ast_open_key(ast);
136 
137 	/* Find out whether P2A works or whether to use device-tree */
138 	ast_detect_config_mode(dev, &scu_rev);
139 
140 	/* Identify chipset */
141 	if (dev->pdev->device == PCI_CHIP_AST1180) {
142 		ast->chip = AST1100;
143 		DRM_INFO("AST 1180 detected\n");
144 	} else {
145 		if (dev->pdev->revision >= 0x40) {
146 			ast->chip = AST2500;
147 			DRM_INFO("AST 2500 detected\n");
148 		} else if (dev->pdev->revision >= 0x30) {
149 			ast->chip = AST2400;
150 			DRM_INFO("AST 2400 detected\n");
151 		} else if (dev->pdev->revision >= 0x20) {
152 			ast->chip = AST2300;
153 			DRM_INFO("AST 2300 detected\n");
154 		} else if (dev->pdev->revision >= 0x10) {
155 			switch (scu_rev & 0x0300) {
156 			case 0x0200:
157 				ast->chip = AST1100;
158 				DRM_INFO("AST 1100 detected\n");
159 				break;
160 			case 0x0100:
161 				ast->chip = AST2200;
162 				DRM_INFO("AST 2200 detected\n");
163 				break;
164 			case 0x0000:
165 				ast->chip = AST2150;
166 				DRM_INFO("AST 2150 detected\n");
167 				break;
168 			default:
169 				ast->chip = AST2100;
170 				DRM_INFO("AST 2100 detected\n");
171 				break;
172 			}
173 			ast->vga2_clone = false;
174 		} else {
175 			ast->chip = AST2000;
176 			DRM_INFO("AST 2000 detected\n");
177 		}
178 	}
179 
180 	/* Check if we support wide screen */
181 	switch (ast->chip) {
182 	case AST1180:
183 		ast->support_wide_screen = true;
184 		break;
185 	case AST2000:
186 		ast->support_wide_screen = false;
187 		break;
188 	default:
189 		jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd0, 0xff);
190 		if (!(jreg & 0x80))
191 			ast->support_wide_screen = true;
192 		else if (jreg & 0x01)
193 			ast->support_wide_screen = true;
194 		else {
195 			ast->support_wide_screen = false;
196 			if (ast->chip == AST2300 &&
197 			    (scu_rev & 0x300) == 0x0) /* ast1300 */
198 				ast->support_wide_screen = true;
199 			if (ast->chip == AST2400 &&
200 			    (scu_rev & 0x300) == 0x100) /* ast1400 */
201 				ast->support_wide_screen = true;
202 			if (ast->chip == AST2500 &&
203 			    scu_rev == 0x100)           /* ast2510 */
204 				ast->support_wide_screen = true;
205 		}
206 		break;
207 	}
208 
209 	/* Check 3rd Tx option (digital output afaik) */
210 	ast->tx_chip_type = AST_TX_NONE;
211 
212 	/*
213 	 * VGACRA3 Enhanced Color Mode Register, check if DVO is already
214 	 * enabled, in that case, assume we have a SIL164 TMDS transmitter
215 	 *
216 	 * Don't make that assumption if we the chip wasn't enabled and
217 	 * is at power-on reset, otherwise we'll incorrectly "detect" a
218 	 * SIL164 when there is none.
219 	 */
220 	if (!*need_post) {
221 		jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xa3, 0xff);
222 		if (jreg & 0x80)
223 			ast->tx_chip_type = AST_TX_SIL164;
224 	}
225 
226 	if ((ast->chip == AST2300) || (ast->chip == AST2400)) {
227 		/*
228 		 * On AST2300 and 2400, look the configuration set by the SoC in
229 		 * the SOC scratch register #1 bits 11:8 (interestingly marked
230 		 * as "reserved" in the spec)
231 		 */
232 		jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd1, 0xff);
233 		switch (jreg) {
234 		case 0x04:
235 			ast->tx_chip_type = AST_TX_SIL164;
236 			break;
237 		case 0x08:
238 			ast->dp501_fw_addr = kzalloc(32*1024, GFP_KERNEL);
239 			if (ast->dp501_fw_addr) {
240 				/* backup firmware */
241 				if (ast_backup_fw(dev, ast->dp501_fw_addr, 32*1024)) {
242 					kfree(ast->dp501_fw_addr);
243 					ast->dp501_fw_addr = NULL;
244 				}
245 			}
246 			/* fallthrough */
247 		case 0x0c:
248 			ast->tx_chip_type = AST_TX_DP501;
249 		}
250 	}
251 
252 	/* Print stuff for diagnostic purposes */
253 	switch(ast->tx_chip_type) {
254 	case AST_TX_SIL164:
255 		DRM_INFO("Using Sil164 TMDS transmitter\n");
256 		break;
257 	case AST_TX_DP501:
258 		DRM_INFO("Using DP501 DisplayPort transmitter\n");
259 		break;
260 	default:
261 		DRM_INFO("Analog VGA only\n");
262 	}
263 	return 0;
264 }
265 
266 static int ast_get_dram_info(struct drm_device *dev)
267 {
268 	struct device_node *np = dev->pdev->dev.of_node;
269 	struct ast_private *ast = dev->dev_private;
270 	uint32_t mcr_cfg, mcr_scu_mpll, mcr_scu_strap;
271 	uint32_t denum, num, div, ref_pll, dsel;
272 
273 	switch (ast->config_mode) {
274 	case ast_use_dt:
275 		/*
276 		 * If some properties are missing, use reasonable
277 		 * defaults for AST2400
278 		 */
279 		if (of_property_read_u32(np, "aspeed,mcr-configuration",
280 					 &mcr_cfg))
281 			mcr_cfg = 0x00000577;
282 		if (of_property_read_u32(np, "aspeed,mcr-scu-mpll",
283 					 &mcr_scu_mpll))
284 			mcr_scu_mpll = 0x000050C0;
285 		if (of_property_read_u32(np, "aspeed,mcr-scu-strap",
286 					 &mcr_scu_strap))
287 			mcr_scu_strap = 0;
288 		break;
289 	case ast_use_p2a:
290 		ast_write32(ast, 0xf004, 0x1e6e0000);
291 		ast_write32(ast, 0xf000, 0x1);
292 		mcr_cfg = ast_read32(ast, 0x10004);
293 		mcr_scu_mpll = ast_read32(ast, 0x10120);
294 		mcr_scu_strap = ast_read32(ast, 0x10170);
295 		break;
296 	case ast_use_defaults:
297 	default:
298 		ast->dram_bus_width = 16;
299 		ast->dram_type = AST_DRAM_1Gx16;
300 		if (ast->chip == AST2500)
301 			ast->mclk = 800;
302 		else
303 			ast->mclk = 396;
304 		return 0;
305 	}
306 
307 	if (mcr_cfg & 0x40)
308 		ast->dram_bus_width = 16;
309 	else
310 		ast->dram_bus_width = 32;
311 
312 	if (ast->chip == AST2500) {
313 		switch (mcr_cfg & 0x03) {
314 		case 0:
315 			ast->dram_type = AST_DRAM_1Gx16;
316 			break;
317 		default:
318 		case 1:
319 			ast->dram_type = AST_DRAM_2Gx16;
320 			break;
321 		case 2:
322 			ast->dram_type = AST_DRAM_4Gx16;
323 			break;
324 		case 3:
325 			ast->dram_type = AST_DRAM_8Gx16;
326 			break;
327 		}
328 	} else if (ast->chip == AST2300 || ast->chip == AST2400) {
329 		switch (mcr_cfg & 0x03) {
330 		case 0:
331 			ast->dram_type = AST_DRAM_512Mx16;
332 			break;
333 		default:
334 		case 1:
335 			ast->dram_type = AST_DRAM_1Gx16;
336 			break;
337 		case 2:
338 			ast->dram_type = AST_DRAM_2Gx16;
339 			break;
340 		case 3:
341 			ast->dram_type = AST_DRAM_4Gx16;
342 			break;
343 		}
344 	} else {
345 		switch (mcr_cfg & 0x0c) {
346 		case 0:
347 		case 4:
348 			ast->dram_type = AST_DRAM_512Mx16;
349 			break;
350 		case 8:
351 			if (mcr_cfg & 0x40)
352 				ast->dram_type = AST_DRAM_1Gx16;
353 			else
354 				ast->dram_type = AST_DRAM_512Mx32;
355 			break;
356 		case 0xc:
357 			ast->dram_type = AST_DRAM_1Gx32;
358 			break;
359 		}
360 	}
361 
362 	if (mcr_scu_strap & 0x2000)
363 		ref_pll = 14318;
364 	else
365 		ref_pll = 12000;
366 
367 	denum = mcr_scu_mpll & 0x1f;
368 	num = (mcr_scu_mpll & 0x3fe0) >> 5;
369 	dsel = (mcr_scu_mpll & 0xc000) >> 14;
370 	switch (dsel) {
371 	case 3:
372 		div = 0x4;
373 		break;
374 	case 2:
375 	case 1:
376 		div = 0x2;
377 		break;
378 	default:
379 		div = 0x1;
380 		break;
381 	}
382 	ast->mclk = ref_pll * (num + 2) / ((denum + 2) * (div * 1000));
383 	return 0;
384 }
385 
386 static void ast_user_framebuffer_destroy(struct drm_framebuffer *fb)
387 {
388 	struct ast_framebuffer *ast_fb = to_ast_framebuffer(fb);
389 
390 	drm_gem_object_unreference_unlocked(ast_fb->obj);
391 	drm_framebuffer_cleanup(fb);
392 	kfree(fb);
393 }
394 
395 static const struct drm_framebuffer_funcs ast_fb_funcs = {
396 	.destroy = ast_user_framebuffer_destroy,
397 };
398 
399 
400 int ast_framebuffer_init(struct drm_device *dev,
401 			 struct ast_framebuffer *ast_fb,
402 			 const struct drm_mode_fb_cmd2 *mode_cmd,
403 			 struct drm_gem_object *obj)
404 {
405 	int ret;
406 
407 	drm_helper_mode_fill_fb_struct(dev, &ast_fb->base, mode_cmd);
408 	ast_fb->obj = obj;
409 	ret = drm_framebuffer_init(dev, &ast_fb->base, &ast_fb_funcs);
410 	if (ret) {
411 		DRM_ERROR("framebuffer init failed %d\n", ret);
412 		return ret;
413 	}
414 	return 0;
415 }
416 
417 static struct drm_framebuffer *
418 ast_user_framebuffer_create(struct drm_device *dev,
419 	       struct drm_file *filp,
420 	       const struct drm_mode_fb_cmd2 *mode_cmd)
421 {
422 	struct drm_gem_object *obj;
423 	struct ast_framebuffer *ast_fb;
424 	int ret;
425 
426 	obj = drm_gem_object_lookup(filp, mode_cmd->handles[0]);
427 	if (obj == NULL)
428 		return ERR_PTR(-ENOENT);
429 
430 	ast_fb = kzalloc(sizeof(*ast_fb), GFP_KERNEL);
431 	if (!ast_fb) {
432 		drm_gem_object_unreference_unlocked(obj);
433 		return ERR_PTR(-ENOMEM);
434 	}
435 
436 	ret = ast_framebuffer_init(dev, ast_fb, mode_cmd, obj);
437 	if (ret) {
438 		drm_gem_object_unreference_unlocked(obj);
439 		kfree(ast_fb);
440 		return ERR_PTR(ret);
441 	}
442 	return &ast_fb->base;
443 }
444 
445 static const struct drm_mode_config_funcs ast_mode_funcs = {
446 	.fb_create = ast_user_framebuffer_create,
447 };
448 
449 static u32 ast_get_vram_info(struct drm_device *dev)
450 {
451 	struct ast_private *ast = dev->dev_private;
452 	u8 jreg;
453 	u32 vram_size;
454 	ast_open_key(ast);
455 
456 	vram_size = AST_VIDMEM_DEFAULT_SIZE;
457 	jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xaa, 0xff);
458 	switch (jreg & 3) {
459 	case 0: vram_size = AST_VIDMEM_SIZE_8M; break;
460 	case 1: vram_size = AST_VIDMEM_SIZE_16M; break;
461 	case 2: vram_size = AST_VIDMEM_SIZE_32M; break;
462 	case 3: vram_size = AST_VIDMEM_SIZE_64M; break;
463 	}
464 
465 	jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0x99, 0xff);
466 	switch (jreg & 0x03) {
467 	case 1:
468 		vram_size -= 0x100000;
469 		break;
470 	case 2:
471 		vram_size -= 0x200000;
472 		break;
473 	case 3:
474 		vram_size -= 0x400000;
475 		break;
476 	}
477 
478 	return vram_size;
479 }
480 
481 int ast_driver_load(struct drm_device *dev, unsigned long flags)
482 {
483 	struct ast_private *ast;
484 	bool need_post;
485 	int ret = 0;
486 
487 	ast = kzalloc(sizeof(struct ast_private), GFP_KERNEL);
488 	if (!ast)
489 		return -ENOMEM;
490 
491 	dev->dev_private = ast;
492 	ast->dev = dev;
493 
494 	ast->regs = pci_iomap(dev->pdev, 1, 0);
495 	if (!ast->regs) {
496 		ret = -EIO;
497 		goto out_free;
498 	}
499 
500 	/*
501 	 * If we don't have IO space at all, use MMIO now and
502 	 * assume the chip has MMIO enabled by default (rev 0x20
503 	 * and higher).
504 	 */
505 	if (!(pci_resource_flags(dev->pdev, 2) & IORESOURCE_IO)) {
506 		DRM_INFO("platform has no IO space, trying MMIO\n");
507 		ast->ioregs = ast->regs + AST_IO_MM_OFFSET;
508 	}
509 
510 	/* "map" IO regs if the above hasn't done so already */
511 	if (!ast->ioregs) {
512 		ast->ioregs = pci_iomap(dev->pdev, 2, 0);
513 		if (!ast->ioregs) {
514 			ret = -EIO;
515 			goto out_free;
516 		}
517 	}
518 
519 	ast_detect_chip(dev, &need_post);
520 
521 	if (need_post)
522 		ast_post_gpu(dev);
523 
524 	if (ast->chip != AST1180) {
525 		ret = ast_get_dram_info(dev);
526 		if (ret)
527 			goto out_free;
528 		ast->vram_size = ast_get_vram_info(dev);
529 		DRM_INFO("dram MCLK=%u Mhz type=%d bus_width=%d size=%08x\n",
530 			 ast->mclk, ast->dram_type,
531 			 ast->dram_bus_width, ast->vram_size);
532 	}
533 
534 	ret = ast_mm_init(ast);
535 	if (ret)
536 		goto out_free;
537 
538 	drm_mode_config_init(dev);
539 
540 	dev->mode_config.funcs = (void *)&ast_mode_funcs;
541 	dev->mode_config.min_width = 0;
542 	dev->mode_config.min_height = 0;
543 	dev->mode_config.preferred_depth = 24;
544 	dev->mode_config.prefer_shadow = 1;
545 	dev->mode_config.fb_base = pci_resource_start(ast->dev->pdev, 0);
546 
547 	if (ast->chip == AST2100 ||
548 	    ast->chip == AST2200 ||
549 	    ast->chip == AST2300 ||
550 	    ast->chip == AST2400 ||
551 	    ast->chip == AST2500 ||
552 	    ast->chip == AST1180) {
553 		dev->mode_config.max_width = 1920;
554 		dev->mode_config.max_height = 2048;
555 	} else {
556 		dev->mode_config.max_width = 1600;
557 		dev->mode_config.max_height = 1200;
558 	}
559 
560 	ret = ast_mode_init(dev);
561 	if (ret)
562 		goto out_free;
563 
564 	ret = ast_fbdev_init(dev);
565 	if (ret)
566 		goto out_free;
567 
568 	return 0;
569 out_free:
570 	kfree(ast);
571 	dev->dev_private = NULL;
572 	return ret;
573 }
574 
575 void ast_driver_unload(struct drm_device *dev)
576 {
577 	struct ast_private *ast = dev->dev_private;
578 
579 	kfree(ast->dp501_fw_addr);
580 	ast_mode_fini(dev);
581 	ast_fbdev_fini(dev);
582 	drm_mode_config_cleanup(dev);
583 
584 	ast_mm_fini(ast);
585 	pci_iounmap(dev->pdev, ast->ioregs);
586 	pci_iounmap(dev->pdev, ast->regs);
587 	kfree(ast);
588 }
589 
590 int ast_gem_create(struct drm_device *dev,
591 		   u32 size, bool iskernel,
592 		   struct drm_gem_object **obj)
593 {
594 	struct ast_bo *astbo;
595 	int ret;
596 
597 	*obj = NULL;
598 
599 	size = roundup(size, PAGE_SIZE);
600 	if (size == 0)
601 		return -EINVAL;
602 
603 	ret = ast_bo_create(dev, size, 0, 0, &astbo);
604 	if (ret) {
605 		if (ret != -ERESTARTSYS)
606 			DRM_ERROR("failed to allocate GEM object\n");
607 		return ret;
608 	}
609 	*obj = &astbo->gem;
610 	return 0;
611 }
612 
613 int ast_dumb_create(struct drm_file *file,
614 		    struct drm_device *dev,
615 		    struct drm_mode_create_dumb *args)
616 {
617 	int ret;
618 	struct drm_gem_object *gobj;
619 	u32 handle;
620 
621 	args->pitch = args->width * ((args->bpp + 7) / 8);
622 	args->size = args->pitch * args->height;
623 
624 	ret = ast_gem_create(dev, args->size, false,
625 			     &gobj);
626 	if (ret)
627 		return ret;
628 
629 	ret = drm_gem_handle_create(file, gobj, &handle);
630 	drm_gem_object_unreference_unlocked(gobj);
631 	if (ret)
632 		return ret;
633 
634 	args->handle = handle;
635 	return 0;
636 }
637 
638 static void ast_bo_unref(struct ast_bo **bo)
639 {
640 	struct ttm_buffer_object *tbo;
641 
642 	if ((*bo) == NULL)
643 		return;
644 
645 	tbo = &((*bo)->bo);
646 	ttm_bo_unref(&tbo);
647 	*bo = NULL;
648 }
649 
650 void ast_gem_free_object(struct drm_gem_object *obj)
651 {
652 	struct ast_bo *ast_bo = gem_to_ast_bo(obj);
653 
654 	ast_bo_unref(&ast_bo);
655 }
656 
657 
658 static inline u64 ast_bo_mmap_offset(struct ast_bo *bo)
659 {
660 	return drm_vma_node_offset_addr(&bo->bo.vma_node);
661 }
662 int
663 ast_dumb_mmap_offset(struct drm_file *file,
664 		     struct drm_device *dev,
665 		     uint32_t handle,
666 		     uint64_t *offset)
667 {
668 	struct drm_gem_object *obj;
669 	struct ast_bo *bo;
670 
671 	obj = drm_gem_object_lookup(file, handle);
672 	if (obj == NULL)
673 		return -ENOENT;
674 
675 	bo = gem_to_ast_bo(obj);
676 	*offset = ast_bo_mmap_offset(bo);
677 
678 	drm_gem_object_unreference_unlocked(obj);
679 
680 	return 0;
681 
682 }
683 
684