Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog
[pandora-kernel.git] / drivers / gpu / drm / radeon / radeon_bios.c
1 /*
2  * Copyright 2008 Advanced Micro Devices, Inc.
3  * Copyright 2008 Red Hat Inc.
4  * Copyright 2009 Jerome Glisse.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22  * OTHER DEALINGS IN THE SOFTWARE.
23  *
24  * Authors: Dave Airlie
25  *          Alex Deucher
26  *          Jerome Glisse
27  */
28 #include "drmP.h"
29 #include "radeon_reg.h"
30 #include "radeon.h"
31 #include "atom.h"
32
33 #include <linux/vga_switcheroo.h>
34 #include <linux/slab.h>
35 /*
36  * BIOS.
37  */
38
39 /* If you boot an IGP board with a discrete card as the primary,
40  * the IGP rom is not accessible via the rom bar as the IGP rom is
41  * part of the system bios.  On boot, the system bios puts a
42  * copy of the igp rom at the start of vram if a discrete card is
43  * present.
44  */
45 static bool igp_read_bios_from_vram(struct radeon_device *rdev)
46 {
47         uint8_t __iomem *bios;
48         resource_size_t vram_base;
49         resource_size_t size = 256 * 1024; /* ??? */
50
51         if (!(rdev->flags & RADEON_IS_IGP))
52                 if (!radeon_card_posted(rdev))
53                         return false;
54
55         rdev->bios = NULL;
56         vram_base = pci_resource_start(rdev->pdev, 0);
57         bios = ioremap(vram_base, size);
58         if (!bios) {
59                 return false;
60         }
61
62         if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
63                 iounmap(bios);
64                 return false;
65         }
66         rdev->bios = kmalloc(size, GFP_KERNEL);
67         if (rdev->bios == NULL) {
68                 iounmap(bios);
69                 return false;
70         }
71         memcpy_fromio(rdev->bios, bios, size);
72         iounmap(bios);
73         return true;
74 }
75
76 static bool radeon_read_bios(struct radeon_device *rdev)
77 {
78         uint8_t __iomem *bios;
79         size_t size;
80
81         rdev->bios = NULL;
82         /* XXX: some cards may return 0 for rom size? ddx has a workaround */
83         bios = pci_map_rom(rdev->pdev, &size);
84         if (!bios) {
85                 return false;
86         }
87
88         if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
89                 pci_unmap_rom(rdev->pdev, bios);
90                 return false;
91         }
92         rdev->bios = kmemdup(bios, size, GFP_KERNEL);
93         if (rdev->bios == NULL) {
94                 pci_unmap_rom(rdev->pdev, bios);
95                 return false;
96         }
97         pci_unmap_rom(rdev->pdev, bios);
98         return true;
99 }
100
101 /* ATRM is used to get the BIOS on the discrete cards in
102  * dual-gpu systems.
103  */
104 static bool radeon_atrm_get_bios(struct radeon_device *rdev)
105 {
106         int ret;
107         int size = 256 * 1024;
108         int i;
109
110         if (!radeon_atrm_supported(rdev->pdev))
111                 return false;
112
113         rdev->bios = kmalloc(size, GFP_KERNEL);
114         if (!rdev->bios) {
115                 DRM_ERROR("Unable to allocate bios\n");
116                 return false;
117         }
118
119         for (i = 0; i < size / ATRM_BIOS_PAGE; i++) {
120                 ret = radeon_atrm_get_bios_chunk(rdev->bios,
121                                                  (i * ATRM_BIOS_PAGE),
122                                                  ATRM_BIOS_PAGE);
123                 if (ret <= 0)
124                         break;
125         }
126
127         if (i == 0 || rdev->bios[0] != 0x55 || rdev->bios[1] != 0xaa) {
128                 kfree(rdev->bios);
129                 return false;
130         }
131         return true;
132 }
133
134 static bool ni_read_disabled_bios(struct radeon_device *rdev)
135 {
136         u32 bus_cntl;
137         u32 d1vga_control;
138         u32 d2vga_control;
139         u32 vga_render_control;
140         u32 rom_cntl;
141         bool r;
142
143         bus_cntl = RREG32(R600_BUS_CNTL);
144         d1vga_control = RREG32(AVIVO_D1VGA_CONTROL);
145         d2vga_control = RREG32(AVIVO_D2VGA_CONTROL);
146         vga_render_control = RREG32(AVIVO_VGA_RENDER_CONTROL);
147         rom_cntl = RREG32(R600_ROM_CNTL);
148
149         /* enable the rom */
150         WREG32(R600_BUS_CNTL, (bus_cntl & ~R600_BIOS_ROM_DIS));
151         /* Disable VGA mode */
152         WREG32(AVIVO_D1VGA_CONTROL,
153                (d1vga_control & ~(AVIVO_DVGA_CONTROL_MODE_ENABLE |
154                 AVIVO_DVGA_CONTROL_TIMING_SELECT)));
155         WREG32(AVIVO_D2VGA_CONTROL,
156                (d2vga_control & ~(AVIVO_DVGA_CONTROL_MODE_ENABLE |
157                 AVIVO_DVGA_CONTROL_TIMING_SELECT)));
158         WREG32(AVIVO_VGA_RENDER_CONTROL,
159                (vga_render_control & ~AVIVO_VGA_VSTATUS_CNTL_MASK));
160         WREG32(R600_ROM_CNTL, rom_cntl | R600_SCK_OVERWRITE);
161
162         r = radeon_read_bios(rdev);
163
164         /* restore regs */
165         WREG32(R600_BUS_CNTL, bus_cntl);
166         WREG32(AVIVO_D1VGA_CONTROL, d1vga_control);
167         WREG32(AVIVO_D2VGA_CONTROL, d2vga_control);
168         WREG32(AVIVO_VGA_RENDER_CONTROL, vga_render_control);
169         WREG32(R600_ROM_CNTL, rom_cntl);
170         return r;
171 }
172
173 static bool r700_read_disabled_bios(struct radeon_device *rdev)
174 {
175         uint32_t viph_control;
176         uint32_t bus_cntl;
177         uint32_t d1vga_control;
178         uint32_t d2vga_control;
179         uint32_t vga_render_control;
180         uint32_t rom_cntl;
181         uint32_t cg_spll_func_cntl = 0;
182         uint32_t cg_spll_status;
183         bool r;
184
185         viph_control = RREG32(RADEON_VIPH_CONTROL);
186         bus_cntl = RREG32(R600_BUS_CNTL);
187         d1vga_control = RREG32(AVIVO_D1VGA_CONTROL);
188         d2vga_control = RREG32(AVIVO_D2VGA_CONTROL);
189         vga_render_control = RREG32(AVIVO_VGA_RENDER_CONTROL);
190         rom_cntl = RREG32(R600_ROM_CNTL);
191
192         /* disable VIP */
193         WREG32(RADEON_VIPH_CONTROL, (viph_control & ~RADEON_VIPH_EN));
194         /* enable the rom */
195         WREG32(R600_BUS_CNTL, (bus_cntl & ~R600_BIOS_ROM_DIS));
196         /* Disable VGA mode */
197         WREG32(AVIVO_D1VGA_CONTROL,
198                (d1vga_control & ~(AVIVO_DVGA_CONTROL_MODE_ENABLE |
199                 AVIVO_DVGA_CONTROL_TIMING_SELECT)));
200         WREG32(AVIVO_D2VGA_CONTROL,
201                (d2vga_control & ~(AVIVO_DVGA_CONTROL_MODE_ENABLE |
202                 AVIVO_DVGA_CONTROL_TIMING_SELECT)));
203         WREG32(AVIVO_VGA_RENDER_CONTROL,
204                (vga_render_control & ~AVIVO_VGA_VSTATUS_CNTL_MASK));
205
206         if (rdev->family == CHIP_RV730) {
207                 cg_spll_func_cntl = RREG32(R600_CG_SPLL_FUNC_CNTL);
208
209                 /* enable bypass mode */
210                 WREG32(R600_CG_SPLL_FUNC_CNTL, (cg_spll_func_cntl |
211                                                 R600_SPLL_BYPASS_EN));
212
213                 /* wait for SPLL_CHG_STATUS to change to 1 */
214                 cg_spll_status = 0;
215                 while (!(cg_spll_status & R600_SPLL_CHG_STATUS))
216                         cg_spll_status = RREG32(R600_CG_SPLL_STATUS);
217
218                 WREG32(R600_ROM_CNTL, (rom_cntl & ~R600_SCK_OVERWRITE));
219         } else
220                 WREG32(R600_ROM_CNTL, (rom_cntl | R600_SCK_OVERWRITE));
221
222         r = radeon_read_bios(rdev);
223
224         /* restore regs */
225         if (rdev->family == CHIP_RV730) {
226                 WREG32(R600_CG_SPLL_FUNC_CNTL, cg_spll_func_cntl);
227
228                 /* wait for SPLL_CHG_STATUS to change to 1 */
229                 cg_spll_status = 0;
230                 while (!(cg_spll_status & R600_SPLL_CHG_STATUS))
231                         cg_spll_status = RREG32(R600_CG_SPLL_STATUS);
232         }
233         WREG32(RADEON_VIPH_CONTROL, viph_control);
234         WREG32(R600_BUS_CNTL, bus_cntl);
235         WREG32(AVIVO_D1VGA_CONTROL, d1vga_control);
236         WREG32(AVIVO_D2VGA_CONTROL, d2vga_control);
237         WREG32(AVIVO_VGA_RENDER_CONTROL, vga_render_control);
238         WREG32(R600_ROM_CNTL, rom_cntl);
239         return r;
240 }
241
242 static bool r600_read_disabled_bios(struct radeon_device *rdev)
243 {
244         uint32_t viph_control;
245         uint32_t bus_cntl;
246         uint32_t d1vga_control;
247         uint32_t d2vga_control;
248         uint32_t vga_render_control;
249         uint32_t rom_cntl;
250         uint32_t general_pwrmgt;
251         uint32_t low_vid_lower_gpio_cntl;
252         uint32_t medium_vid_lower_gpio_cntl;
253         uint32_t high_vid_lower_gpio_cntl;
254         uint32_t ctxsw_vid_lower_gpio_cntl;
255         uint32_t lower_gpio_enable;
256         bool r;
257
258         viph_control = RREG32(RADEON_VIPH_CONTROL);
259         bus_cntl = RREG32(R600_BUS_CNTL);
260         d1vga_control = RREG32(AVIVO_D1VGA_CONTROL);
261         d2vga_control = RREG32(AVIVO_D2VGA_CONTROL);
262         vga_render_control = RREG32(AVIVO_VGA_RENDER_CONTROL);
263         rom_cntl = RREG32(R600_ROM_CNTL);
264         general_pwrmgt = RREG32(R600_GENERAL_PWRMGT);
265         low_vid_lower_gpio_cntl = RREG32(R600_LOW_VID_LOWER_GPIO_CNTL);
266         medium_vid_lower_gpio_cntl = RREG32(R600_MEDIUM_VID_LOWER_GPIO_CNTL);
267         high_vid_lower_gpio_cntl = RREG32(R600_HIGH_VID_LOWER_GPIO_CNTL);
268         ctxsw_vid_lower_gpio_cntl = RREG32(R600_CTXSW_VID_LOWER_GPIO_CNTL);
269         lower_gpio_enable = RREG32(R600_LOWER_GPIO_ENABLE);
270
271         /* disable VIP */
272         WREG32(RADEON_VIPH_CONTROL, (viph_control & ~RADEON_VIPH_EN));
273         /* enable the rom */
274         WREG32(R600_BUS_CNTL, (bus_cntl & ~R600_BIOS_ROM_DIS));
275         /* Disable VGA mode */
276         WREG32(AVIVO_D1VGA_CONTROL,
277                (d1vga_control & ~(AVIVO_DVGA_CONTROL_MODE_ENABLE |
278                 AVIVO_DVGA_CONTROL_TIMING_SELECT)));
279         WREG32(AVIVO_D2VGA_CONTROL,
280                (d2vga_control & ~(AVIVO_DVGA_CONTROL_MODE_ENABLE |
281                 AVIVO_DVGA_CONTROL_TIMING_SELECT)));
282         WREG32(AVIVO_VGA_RENDER_CONTROL,
283                (vga_render_control & ~AVIVO_VGA_VSTATUS_CNTL_MASK));
284
285         WREG32(R600_ROM_CNTL,
286                ((rom_cntl & ~R600_SCK_PRESCALE_CRYSTAL_CLK_MASK) |
287                 (1 << R600_SCK_PRESCALE_CRYSTAL_CLK_SHIFT) |
288                 R600_SCK_OVERWRITE));
289
290         WREG32(R600_GENERAL_PWRMGT, (general_pwrmgt & ~R600_OPEN_DRAIN_PADS));
291         WREG32(R600_LOW_VID_LOWER_GPIO_CNTL,
292                (low_vid_lower_gpio_cntl & ~0x400));
293         WREG32(R600_MEDIUM_VID_LOWER_GPIO_CNTL,
294                (medium_vid_lower_gpio_cntl & ~0x400));
295         WREG32(R600_HIGH_VID_LOWER_GPIO_CNTL,
296                (high_vid_lower_gpio_cntl & ~0x400));
297         WREG32(R600_CTXSW_VID_LOWER_GPIO_CNTL,
298                (ctxsw_vid_lower_gpio_cntl & ~0x400));
299         WREG32(R600_LOWER_GPIO_ENABLE, (lower_gpio_enable | 0x400));
300
301         r = radeon_read_bios(rdev);
302
303         /* restore regs */
304         WREG32(RADEON_VIPH_CONTROL, viph_control);
305         WREG32(R600_BUS_CNTL, bus_cntl);
306         WREG32(AVIVO_D1VGA_CONTROL, d1vga_control);
307         WREG32(AVIVO_D2VGA_CONTROL, d2vga_control);
308         WREG32(AVIVO_VGA_RENDER_CONTROL, vga_render_control);
309         WREG32(R600_ROM_CNTL, rom_cntl);
310         WREG32(R600_GENERAL_PWRMGT, general_pwrmgt);
311         WREG32(R600_LOW_VID_LOWER_GPIO_CNTL, low_vid_lower_gpio_cntl);
312         WREG32(R600_MEDIUM_VID_LOWER_GPIO_CNTL, medium_vid_lower_gpio_cntl);
313         WREG32(R600_HIGH_VID_LOWER_GPIO_CNTL, high_vid_lower_gpio_cntl);
314         WREG32(R600_CTXSW_VID_LOWER_GPIO_CNTL, ctxsw_vid_lower_gpio_cntl);
315         WREG32(R600_LOWER_GPIO_ENABLE, lower_gpio_enable);
316         return r;
317 }
318
319 static bool avivo_read_disabled_bios(struct radeon_device *rdev)
320 {
321         uint32_t seprom_cntl1;
322         uint32_t viph_control;
323         uint32_t bus_cntl;
324         uint32_t d1vga_control;
325         uint32_t d2vga_control;
326         uint32_t vga_render_control;
327         uint32_t gpiopad_a;
328         uint32_t gpiopad_en;
329         uint32_t gpiopad_mask;
330         bool r;
331
332         seprom_cntl1 = RREG32(RADEON_SEPROM_CNTL1);
333         viph_control = RREG32(RADEON_VIPH_CONTROL);
334         bus_cntl = RREG32(RADEON_BUS_CNTL);
335         d1vga_control = RREG32(AVIVO_D1VGA_CONTROL);
336         d2vga_control = RREG32(AVIVO_D2VGA_CONTROL);
337         vga_render_control = RREG32(AVIVO_VGA_RENDER_CONTROL);
338         gpiopad_a = RREG32(RADEON_GPIOPAD_A);
339         gpiopad_en = RREG32(RADEON_GPIOPAD_EN);
340         gpiopad_mask = RREG32(RADEON_GPIOPAD_MASK);
341
342         WREG32(RADEON_SEPROM_CNTL1,
343                ((seprom_cntl1 & ~RADEON_SCK_PRESCALE_MASK) |
344                 (0xc << RADEON_SCK_PRESCALE_SHIFT)));
345         WREG32(RADEON_GPIOPAD_A, 0);
346         WREG32(RADEON_GPIOPAD_EN, 0);
347         WREG32(RADEON_GPIOPAD_MASK, 0);
348
349         /* disable VIP */
350         WREG32(RADEON_VIPH_CONTROL, (viph_control & ~RADEON_VIPH_EN));
351
352         /* enable the rom */
353         WREG32(RADEON_BUS_CNTL, (bus_cntl & ~RADEON_BUS_BIOS_DIS_ROM));
354
355         /* Disable VGA mode */
356         WREG32(AVIVO_D1VGA_CONTROL,
357                (d1vga_control & ~(AVIVO_DVGA_CONTROL_MODE_ENABLE |
358                 AVIVO_DVGA_CONTROL_TIMING_SELECT)));
359         WREG32(AVIVO_D2VGA_CONTROL,
360                (d2vga_control & ~(AVIVO_DVGA_CONTROL_MODE_ENABLE |
361                 AVIVO_DVGA_CONTROL_TIMING_SELECT)));
362         WREG32(AVIVO_VGA_RENDER_CONTROL,
363                (vga_render_control & ~AVIVO_VGA_VSTATUS_CNTL_MASK));
364
365         r = radeon_read_bios(rdev);
366
367         /* restore regs */
368         WREG32(RADEON_SEPROM_CNTL1, seprom_cntl1);
369         WREG32(RADEON_VIPH_CONTROL, viph_control);
370         WREG32(RADEON_BUS_CNTL, bus_cntl);
371         WREG32(AVIVO_D1VGA_CONTROL, d1vga_control);
372         WREG32(AVIVO_D2VGA_CONTROL, d2vga_control);
373         WREG32(AVIVO_VGA_RENDER_CONTROL, vga_render_control);
374         WREG32(RADEON_GPIOPAD_A, gpiopad_a);
375         WREG32(RADEON_GPIOPAD_EN, gpiopad_en);
376         WREG32(RADEON_GPIOPAD_MASK, gpiopad_mask);
377         return r;
378 }
379
380 static bool legacy_read_disabled_bios(struct radeon_device *rdev)
381 {
382         uint32_t seprom_cntl1;
383         uint32_t viph_control;
384         uint32_t bus_cntl;
385         uint32_t crtc_gen_cntl;
386         uint32_t crtc2_gen_cntl;
387         uint32_t crtc_ext_cntl;
388         uint32_t fp2_gen_cntl;
389         bool r;
390
391         seprom_cntl1 = RREG32(RADEON_SEPROM_CNTL1);
392         viph_control = RREG32(RADEON_VIPH_CONTROL);
393         bus_cntl = RREG32(RADEON_BUS_CNTL);
394         crtc_gen_cntl = RREG32(RADEON_CRTC_GEN_CNTL);
395         crtc2_gen_cntl = 0;
396         crtc_ext_cntl = RREG32(RADEON_CRTC_EXT_CNTL);
397         fp2_gen_cntl = 0;
398
399         if (rdev->ddev->pci_device == PCI_DEVICE_ID_ATI_RADEON_QY) {
400                 fp2_gen_cntl = RREG32(RADEON_FP2_GEN_CNTL);
401         }
402
403         if (!(rdev->flags & RADEON_SINGLE_CRTC)) {
404                 crtc2_gen_cntl = RREG32(RADEON_CRTC2_GEN_CNTL);
405         }
406
407         WREG32(RADEON_SEPROM_CNTL1,
408                ((seprom_cntl1 & ~RADEON_SCK_PRESCALE_MASK) |
409                 (0xc << RADEON_SCK_PRESCALE_SHIFT)));
410
411         /* disable VIP */
412         WREG32(RADEON_VIPH_CONTROL, (viph_control & ~RADEON_VIPH_EN));
413
414         /* enable the rom */
415         WREG32(RADEON_BUS_CNTL, (bus_cntl & ~RADEON_BUS_BIOS_DIS_ROM));
416
417         /* Turn off mem requests and CRTC for both controllers */
418         WREG32(RADEON_CRTC_GEN_CNTL,
419                ((crtc_gen_cntl & ~RADEON_CRTC_EN) |
420                 (RADEON_CRTC_DISP_REQ_EN_B |
421                  RADEON_CRTC_EXT_DISP_EN)));
422         if (!(rdev->flags & RADEON_SINGLE_CRTC)) {
423                 WREG32(RADEON_CRTC2_GEN_CNTL,
424                        ((crtc2_gen_cntl & ~RADEON_CRTC2_EN) |
425                         RADEON_CRTC2_DISP_REQ_EN_B));
426         }
427         /* Turn off CRTC */
428         WREG32(RADEON_CRTC_EXT_CNTL,
429                ((crtc_ext_cntl & ~RADEON_CRTC_CRT_ON) |
430                 (RADEON_CRTC_SYNC_TRISTAT |
431                  RADEON_CRTC_DISPLAY_DIS)));
432
433         if (rdev->ddev->pci_device == PCI_DEVICE_ID_ATI_RADEON_QY) {
434                 WREG32(RADEON_FP2_GEN_CNTL, (fp2_gen_cntl & ~RADEON_FP2_ON));
435         }
436
437         r = radeon_read_bios(rdev);
438
439         /* restore regs */
440         WREG32(RADEON_SEPROM_CNTL1, seprom_cntl1);
441         WREG32(RADEON_VIPH_CONTROL, viph_control);
442         WREG32(RADEON_BUS_CNTL, bus_cntl);
443         WREG32(RADEON_CRTC_GEN_CNTL, crtc_gen_cntl);
444         if (!(rdev->flags & RADEON_SINGLE_CRTC)) {
445                 WREG32(RADEON_CRTC2_GEN_CNTL, crtc2_gen_cntl);
446         }
447         WREG32(RADEON_CRTC_EXT_CNTL, crtc_ext_cntl);
448         if (rdev->ddev->pci_device == PCI_DEVICE_ID_ATI_RADEON_QY) {
449                 WREG32(RADEON_FP2_GEN_CNTL, fp2_gen_cntl);
450         }
451         return r;
452 }
453
454 static bool radeon_read_disabled_bios(struct radeon_device *rdev)
455 {
456         if (rdev->flags & RADEON_IS_IGP)
457                 return igp_read_bios_from_vram(rdev);
458         else if (rdev->family >= CHIP_BARTS)
459                 return ni_read_disabled_bios(rdev);
460         else if (rdev->family >= CHIP_RV770)
461                 return r700_read_disabled_bios(rdev);
462         else if (rdev->family >= CHIP_R600)
463                 return r600_read_disabled_bios(rdev);
464         else if (rdev->family >= CHIP_RS600)
465                 return avivo_read_disabled_bios(rdev);
466         else
467                 return legacy_read_disabled_bios(rdev);
468 }
469
470
471 bool radeon_get_bios(struct radeon_device *rdev)
472 {
473         bool r;
474         uint16_t tmp;
475
476         r = radeon_atrm_get_bios(rdev);
477         if (r == false)
478                 r = igp_read_bios_from_vram(rdev);
479         if (r == false)
480                 r = radeon_read_bios(rdev);
481         if (r == false) {
482                 r = radeon_read_disabled_bios(rdev);
483         }
484         if (r == false || rdev->bios == NULL) {
485                 DRM_ERROR("Unable to locate a BIOS ROM\n");
486                 rdev->bios = NULL;
487                 return false;
488         }
489         if (rdev->bios[0] != 0x55 || rdev->bios[1] != 0xaa) {
490                 printk("BIOS signature incorrect %x %x\n", rdev->bios[0], rdev->bios[1]);
491                 goto free_bios;
492         }
493
494         tmp = RBIOS16(0x18);
495         if (RBIOS8(tmp + 0x14) != 0x0) {
496                 DRM_INFO("Not an x86 BIOS ROM, not using.\n");
497                 goto free_bios;
498         }
499
500         rdev->bios_header_start = RBIOS16(0x48);
501         if (!rdev->bios_header_start) {
502                 goto free_bios;
503         }
504         tmp = rdev->bios_header_start + 4;
505         if (!memcmp(rdev->bios + tmp, "ATOM", 4) ||
506             !memcmp(rdev->bios + tmp, "MOTA", 4)) {
507                 rdev->is_atom_bios = true;
508         } else {
509                 rdev->is_atom_bios = false;
510         }
511
512         DRM_DEBUG("%sBIOS detected\n", rdev->is_atom_bios ? "ATOM" : "COM");
513         return true;
514 free_bios:
515         kfree(rdev->bios);
516         rdev->bios = NULL;
517         return false;
518 }