Loading...
1/*
2 * Copyright (C) 2009 Red Hat <mjg@redhat.com>
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a 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, sublicense, 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 above copyright notice and this permission notice (including the
13 * next paragraph) shall be included in all copies or substantial
14 * portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
19 * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
20 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 *
24 */
25
26/*
27 * Authors:
28 * Matthew Garrett <mjg@redhat.com>
29 *
30 * Register locations derived from NVClock by Roderick Colenbrander
31 */
32
33#include <linux/apple-gmux.h>
34#include <linux/backlight.h>
35#include <linux/idr.h>
36#include <drm/drm_probe_helper.h>
37
38#include "nouveau_drv.h"
39#include "nouveau_reg.h"
40#include "nouveau_encoder.h"
41#include "nouveau_connector.h"
42#include "nouveau_acpi.h"
43
44static struct ida bl_ida;
45#define BL_NAME_SIZE 15 // 12 for name + 2 for digits + 1 for '\0'
46
47static bool
48nouveau_get_backlight_name(char backlight_name[BL_NAME_SIZE],
49 struct nouveau_backlight *bl)
50{
51 const int nb = ida_alloc_max(&bl_ida, 99, GFP_KERNEL);
52
53 if (nb < 0)
54 return false;
55 if (nb > 0)
56 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
57 else
58 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight");
59 bl->id = nb;
60 return true;
61}
62
63static int
64nv40_get_intensity(struct backlight_device *bd)
65{
66 struct nouveau_encoder *nv_encoder = bl_get_data(bd);
67 struct nouveau_drm *drm = nouveau_drm(nv_encoder->base.base.dev);
68 struct nvif_object *device = &drm->client.device.object;
69 int val = (nvif_rd32(device, NV40_PMC_BACKLIGHT) &
70 NV40_PMC_BACKLIGHT_MASK) >> 16;
71
72 return val;
73}
74
75static int
76nv40_set_intensity(struct backlight_device *bd)
77{
78 struct nouveau_encoder *nv_encoder = bl_get_data(bd);
79 struct nouveau_drm *drm = nouveau_drm(nv_encoder->base.base.dev);
80 struct nvif_object *device = &drm->client.device.object;
81 int val = bd->props.brightness;
82 int reg = nvif_rd32(device, NV40_PMC_BACKLIGHT);
83
84 nvif_wr32(device, NV40_PMC_BACKLIGHT,
85 (val << 16) | (reg & ~NV40_PMC_BACKLIGHT_MASK));
86
87 return 0;
88}
89
90static const struct backlight_ops nv40_bl_ops = {
91 .options = BL_CORE_SUSPENDRESUME,
92 .get_brightness = nv40_get_intensity,
93 .update_status = nv40_set_intensity,
94};
95
96static int
97nv40_backlight_init(struct nouveau_encoder *encoder,
98 struct backlight_properties *props,
99 const struct backlight_ops **ops)
100{
101 struct nouveau_drm *drm = nouveau_drm(encoder->base.base.dev);
102 struct nvif_object *device = &drm->client.device.object;
103
104 if (!(nvif_rd32(device, NV40_PMC_BACKLIGHT) & NV40_PMC_BACKLIGHT_MASK))
105 return -ENODEV;
106
107 props->max_brightness = 31;
108 *ops = &nv40_bl_ops;
109 return 0;
110}
111
112/*
113 * eDP brightness callbacks need to happen under lock, since we need to
114 * enable/disable the backlight ourselves for modesets
115 */
116static int
117nv50_edp_get_brightness(struct backlight_device *bd)
118{
119 struct drm_connector *connector = dev_get_drvdata(bd->dev.parent);
120 struct drm_device *dev = connector->dev;
121 struct drm_crtc *crtc;
122 struct drm_modeset_acquire_ctx ctx;
123 int ret = 0;
124
125 drm_modeset_acquire_init(&ctx, 0);
126
127retry:
128 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
129 if (ret == -EDEADLK)
130 goto deadlock;
131 else if (ret < 0)
132 goto out;
133
134 crtc = connector->state->crtc;
135 if (!crtc)
136 goto out;
137
138 ret = drm_modeset_lock(&crtc->mutex, &ctx);
139 if (ret == -EDEADLK)
140 goto deadlock;
141 else if (ret < 0)
142 goto out;
143
144 if (!crtc->state->active)
145 goto out;
146
147 ret = bd->props.brightness;
148out:
149 drm_modeset_drop_locks(&ctx);
150 drm_modeset_acquire_fini(&ctx);
151 return ret;
152deadlock:
153 drm_modeset_backoff(&ctx);
154 goto retry;
155}
156
157static int
158nv50_edp_set_brightness(struct backlight_device *bd)
159{
160 struct drm_connector *connector = dev_get_drvdata(bd->dev.parent);
161 struct nouveau_connector *nv_connector = nouveau_connector(connector);
162 struct drm_device *dev = connector->dev;
163 struct drm_crtc *crtc;
164 struct drm_dp_aux *aux = &nv_connector->aux;
165 struct nouveau_backlight *nv_bl = nv_connector->backlight;
166 struct drm_modeset_acquire_ctx ctx;
167 int ret = 0;
168
169 drm_modeset_acquire_init(&ctx, 0);
170retry:
171 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
172 if (ret == -EDEADLK)
173 goto deadlock;
174 else if (ret < 0)
175 goto out;
176
177 crtc = connector->state->crtc;
178 if (!crtc)
179 goto out;
180
181 ret = drm_modeset_lock(&crtc->mutex, &ctx);
182 if (ret == -EDEADLK)
183 goto deadlock;
184 else if (ret < 0)
185 goto out;
186
187 if (crtc->state->active)
188 ret = drm_edp_backlight_set_level(aux, &nv_bl->edp_info, bd->props.brightness);
189
190out:
191 drm_modeset_drop_locks(&ctx);
192 drm_modeset_acquire_fini(&ctx);
193 return ret;
194deadlock:
195 drm_modeset_backoff(&ctx);
196 goto retry;
197}
198
199static const struct backlight_ops nv50_edp_bl_ops = {
200 .get_brightness = nv50_edp_get_brightness,
201 .update_status = nv50_edp_set_brightness,
202};
203
204static int
205nv50_get_intensity(struct backlight_device *bd)
206{
207 struct nouveau_encoder *nv_encoder = bl_get_data(bd);
208
209 return nvif_outp_bl_get(&nv_encoder->outp);
210}
211
212static int
213nv50_set_intensity(struct backlight_device *bd)
214{
215 struct nouveau_encoder *nv_encoder = bl_get_data(bd);
216
217 return nvif_outp_bl_set(&nv_encoder->outp, backlight_get_brightness(bd));
218}
219
220static const struct backlight_ops nv50_bl_ops = {
221 .options = BL_CORE_SUSPENDRESUME,
222 .get_brightness = nv50_get_intensity,
223 .update_status = nv50_set_intensity,
224};
225
226/* FIXME: perform backlight probing for eDP _before_ this, this only gets called after connector
227 * registration which happens after the initial modeset
228 */
229static int
230nv50_backlight_init(struct nouveau_backlight *bl,
231 struct nouveau_connector *nv_conn,
232 struct nouveau_encoder *nv_encoder,
233 struct backlight_properties *props,
234 const struct backlight_ops **ops)
235{
236 struct nouveau_drm *drm = nouveau_drm(nv_encoder->base.base.dev);
237
238 /*
239 * Note when this runs the connectors have not been probed yet,
240 * so nv_conn->base.status is not set yet.
241 */
242 if (nvif_outp_bl_get(&nv_encoder->outp) < 0 ||
243 drm_helper_probe_detect(&nv_conn->base, NULL, false) != connector_status_connected)
244 return -ENODEV;
245
246 if (nv_conn->type == DCB_CONNECTOR_eDP) {
247 int ret;
248 u16 current_level;
249 u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE];
250 u8 current_mode;
251
252 ret = drm_dp_dpcd_read(&nv_conn->aux, DP_EDP_DPCD_REV, edp_dpcd,
253 EDP_DISPLAY_CTL_CAP_SIZE);
254 if (ret < 0)
255 return ret;
256
257 /* TODO: Add support for hybrid PWM/DPCD panels */
258 if (drm_edp_backlight_supported(edp_dpcd) &&
259 (edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) &&
260 (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) {
261 NV_DEBUG(drm, "DPCD backlight controls supported on %s\n",
262 nv_conn->base.name);
263
264 ret = drm_edp_backlight_init(&nv_conn->aux, &bl->edp_info, 0, edp_dpcd,
265 ¤t_level, ¤t_mode);
266 if (ret < 0)
267 return ret;
268
269 ret = drm_edp_backlight_enable(&nv_conn->aux, &bl->edp_info, current_level);
270 if (ret < 0) {
271 NV_ERROR(drm, "Failed to enable backlight on %s: %d\n",
272 nv_conn->base.name, ret);
273 return ret;
274 }
275
276 *ops = &nv50_edp_bl_ops;
277 props->brightness = current_level;
278 props->max_brightness = bl->edp_info.max;
279 bl->uses_dpcd = true;
280 return 0;
281 }
282 }
283
284 *ops = &nv50_bl_ops;
285 props->max_brightness = 100;
286 return 0;
287}
288
289int
290nouveau_backlight_init(struct drm_connector *connector)
291{
292 struct nouveau_drm *drm = nouveau_drm(connector->dev);
293 struct nouveau_backlight *bl;
294 struct nouveau_encoder *nv_encoder = NULL;
295 struct nvif_device *device = &drm->client.device;
296 char backlight_name[BL_NAME_SIZE];
297 struct backlight_properties props = {0};
298 const struct backlight_ops *ops;
299 int ret;
300
301 if (apple_gmux_present()) {
302 NV_INFO_ONCE(drm, "Apple GMUX detected: not registering Nouveau backlight interface\n");
303 return 0;
304 }
305
306 if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS)
307 nv_encoder = find_encoder(connector, DCB_OUTPUT_LVDS);
308 else if (connector->connector_type == DRM_MODE_CONNECTOR_eDP)
309 nv_encoder = find_encoder(connector, DCB_OUTPUT_DP);
310 else
311 return 0;
312
313 if (!nv_encoder)
314 return 0;
315
316 bl = kzalloc(sizeof(*bl), GFP_KERNEL);
317 if (!bl)
318 return -ENOMEM;
319
320 switch (device->info.family) {
321 case NV_DEVICE_INFO_V0_CURIE:
322 ret = nv40_backlight_init(nv_encoder, &props, &ops);
323 break;
324 case NV_DEVICE_INFO_V0_TESLA:
325 case NV_DEVICE_INFO_V0_FERMI:
326 case NV_DEVICE_INFO_V0_KEPLER:
327 case NV_DEVICE_INFO_V0_MAXWELL:
328 case NV_DEVICE_INFO_V0_PASCAL:
329 case NV_DEVICE_INFO_V0_VOLTA:
330 case NV_DEVICE_INFO_V0_TURING:
331 case NV_DEVICE_INFO_V0_AMPERE: //XXX: not confirmed
332 ret = nv50_backlight_init(bl, nouveau_connector(connector),
333 nv_encoder, &props, &ops);
334 break;
335 default:
336 ret = 0;
337 goto fail_alloc;
338 }
339
340 if (ret) {
341 if (ret == -ENODEV)
342 ret = 0;
343 goto fail_alloc;
344 }
345
346 if (!nouveau_acpi_video_backlight_use_native()) {
347 NV_INFO(drm, "Skipping nv_backlight registration\n");
348 goto fail_alloc;
349 }
350
351 if (!nouveau_get_backlight_name(backlight_name, bl)) {
352 NV_ERROR(drm, "Failed to retrieve a unique name for the backlight interface\n");
353 goto fail_alloc;
354 }
355
356 props.type = BACKLIGHT_RAW;
357 bl->dev = backlight_device_register(backlight_name, connector->kdev,
358 nv_encoder, ops, &props);
359 if (IS_ERR(bl->dev)) {
360 if (bl->id >= 0)
361 ida_free(&bl_ida, bl->id);
362 ret = PTR_ERR(bl->dev);
363 goto fail_alloc;
364 }
365
366 nouveau_connector(connector)->backlight = bl;
367 if (!bl->dev->props.brightness)
368 bl->dev->props.brightness =
369 bl->dev->ops->get_brightness(bl->dev);
370 backlight_update_status(bl->dev);
371
372 return 0;
373
374fail_alloc:
375 kfree(bl);
376 /*
377 * If we get here we have an internal panel, but no nv_backlight,
378 * try registering an ACPI video backlight device instead.
379 */
380 if (ret == 0)
381 nouveau_acpi_video_register_backlight();
382
383 return ret;
384}
385
386void
387nouveau_backlight_fini(struct drm_connector *connector)
388{
389 struct nouveau_connector *nv_conn = nouveau_connector(connector);
390 struct nouveau_backlight *bl = nv_conn->backlight;
391
392 if (!bl)
393 return;
394
395 if (bl->id >= 0)
396 ida_free(&bl_ida, bl->id);
397
398 backlight_device_unregister(bl->dev);
399 nv_conn->backlight = NULL;
400 kfree(bl);
401}
402
403void
404nouveau_backlight_ctor(void)
405{
406 ida_init(&bl_ida);
407}
408
409void
410nouveau_backlight_dtor(void)
411{
412 ida_destroy(&bl_ida);
413}
1/*
2 * Copyright (C) 2009 Red Hat <mjg@redhat.com>
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a 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, sublicense, 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 above copyright notice and this permission notice (including the
13 * next paragraph) shall be included in all copies or substantial
14 * portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
19 * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
20 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 *
24 */
25
26/*
27 * Authors:
28 * Matthew Garrett <mjg@redhat.com>
29 *
30 * Register locations derived from NVClock by Roderick Colenbrander
31 */
32
33#include <linux/backlight.h>
34#include <linux/acpi.h>
35
36#include "nouveau_drm.h"
37#include "nouveau_reg.h"
38#include "nouveau_encoder.h"
39
40static int
41nv40_get_intensity(struct backlight_device *bd)
42{
43 struct nouveau_drm *drm = bl_get_data(bd);
44 struct nouveau_device *device = nv_device(drm->device);
45 int val = (nv_rd32(device, NV40_PMC_BACKLIGHT) &
46 NV40_PMC_BACKLIGHT_MASK) >> 16;
47
48 return val;
49}
50
51static int
52nv40_set_intensity(struct backlight_device *bd)
53{
54 struct nouveau_drm *drm = bl_get_data(bd);
55 struct nouveau_device *device = nv_device(drm->device);
56 int val = bd->props.brightness;
57 int reg = nv_rd32(device, NV40_PMC_BACKLIGHT);
58
59 nv_wr32(device, NV40_PMC_BACKLIGHT,
60 (val << 16) | (reg & ~NV40_PMC_BACKLIGHT_MASK));
61
62 return 0;
63}
64
65static const struct backlight_ops nv40_bl_ops = {
66 .options = BL_CORE_SUSPENDRESUME,
67 .get_brightness = nv40_get_intensity,
68 .update_status = nv40_set_intensity,
69};
70
71static int
72nv40_backlight_init(struct drm_connector *connector)
73{
74 struct nouveau_drm *drm = nouveau_drm(connector->dev);
75 struct nouveau_device *device = nv_device(drm->device);
76 struct backlight_properties props;
77 struct backlight_device *bd;
78
79 if (!(nv_rd32(device, NV40_PMC_BACKLIGHT) & NV40_PMC_BACKLIGHT_MASK))
80 return 0;
81
82 memset(&props, 0, sizeof(struct backlight_properties));
83 props.type = BACKLIGHT_RAW;
84 props.max_brightness = 31;
85 bd = backlight_device_register("nv_backlight", connector->kdev, drm,
86 &nv40_bl_ops, &props);
87 if (IS_ERR(bd))
88 return PTR_ERR(bd);
89 drm->backlight = bd;
90 bd->props.brightness = nv40_get_intensity(bd);
91 backlight_update_status(bd);
92
93 return 0;
94}
95
96static int
97nv50_get_intensity(struct backlight_device *bd)
98{
99 struct nouveau_encoder *nv_encoder = bl_get_data(bd);
100 struct nouveau_drm *drm = nouveau_drm(nv_encoder->base.base.dev);
101 struct nouveau_device *device = nv_device(drm->device);
102 int or = nv_encoder->or;
103 u32 div = 1025;
104 u32 val;
105
106 val = nv_rd32(device, NV50_PDISP_SOR_PWM_CTL(or));
107 val &= NV50_PDISP_SOR_PWM_CTL_VAL;
108 return ((val * 100) + (div / 2)) / div;
109}
110
111static int
112nv50_set_intensity(struct backlight_device *bd)
113{
114 struct nouveau_encoder *nv_encoder = bl_get_data(bd);
115 struct nouveau_drm *drm = nouveau_drm(nv_encoder->base.base.dev);
116 struct nouveau_device *device = nv_device(drm->device);
117 int or = nv_encoder->or;
118 u32 div = 1025;
119 u32 val = (bd->props.brightness * div) / 100;
120
121 nv_wr32(device, NV50_PDISP_SOR_PWM_CTL(or),
122 NV50_PDISP_SOR_PWM_CTL_NEW | val);
123 return 0;
124}
125
126static const struct backlight_ops nv50_bl_ops = {
127 .options = BL_CORE_SUSPENDRESUME,
128 .get_brightness = nv50_get_intensity,
129 .update_status = nv50_set_intensity,
130};
131
132static int
133nva3_get_intensity(struct backlight_device *bd)
134{
135 struct nouveau_encoder *nv_encoder = bl_get_data(bd);
136 struct nouveau_drm *drm = nouveau_drm(nv_encoder->base.base.dev);
137 struct nouveau_device *device = nv_device(drm->device);
138 int or = nv_encoder->or;
139 u32 div, val;
140
141 div = nv_rd32(device, NV50_PDISP_SOR_PWM_DIV(or));
142 val = nv_rd32(device, NV50_PDISP_SOR_PWM_CTL(or));
143 val &= NVA3_PDISP_SOR_PWM_CTL_VAL;
144 if (div && div >= val)
145 return ((val * 100) + (div / 2)) / div;
146
147 return 100;
148}
149
150static int
151nva3_set_intensity(struct backlight_device *bd)
152{
153 struct nouveau_encoder *nv_encoder = bl_get_data(bd);
154 struct nouveau_drm *drm = nouveau_drm(nv_encoder->base.base.dev);
155 struct nouveau_device *device = nv_device(drm->device);
156 int or = nv_encoder->or;
157 u32 div, val;
158
159 div = nv_rd32(device, NV50_PDISP_SOR_PWM_DIV(or));
160 val = (bd->props.brightness * div) / 100;
161 if (div) {
162 nv_wr32(device, NV50_PDISP_SOR_PWM_CTL(or), val |
163 NV50_PDISP_SOR_PWM_CTL_NEW |
164 NVA3_PDISP_SOR_PWM_CTL_UNK);
165 return 0;
166 }
167
168 return -EINVAL;
169}
170
171static const struct backlight_ops nva3_bl_ops = {
172 .options = BL_CORE_SUSPENDRESUME,
173 .get_brightness = nva3_get_intensity,
174 .update_status = nva3_set_intensity,
175};
176
177static int
178nv50_backlight_init(struct drm_connector *connector)
179{
180 struct nouveau_drm *drm = nouveau_drm(connector->dev);
181 struct nouveau_device *device = nv_device(drm->device);
182 struct nouveau_encoder *nv_encoder;
183 struct backlight_properties props;
184 struct backlight_device *bd;
185 const struct backlight_ops *ops;
186
187 nv_encoder = find_encoder(connector, DCB_OUTPUT_LVDS);
188 if (!nv_encoder) {
189 nv_encoder = find_encoder(connector, DCB_OUTPUT_DP);
190 if (!nv_encoder)
191 return -ENODEV;
192 }
193
194 if (!nv_rd32(device, NV50_PDISP_SOR_PWM_CTL(nv_encoder->or)))
195 return 0;
196
197 if (device->chipset <= 0xa0 ||
198 device->chipset == 0xaa ||
199 device->chipset == 0xac)
200 ops = &nv50_bl_ops;
201 else
202 ops = &nva3_bl_ops;
203
204 memset(&props, 0, sizeof(struct backlight_properties));
205 props.type = BACKLIGHT_RAW;
206 props.max_brightness = 100;
207 bd = backlight_device_register("nv_backlight", connector->kdev,
208 nv_encoder, ops, &props);
209 if (IS_ERR(bd))
210 return PTR_ERR(bd);
211
212 drm->backlight = bd;
213 bd->props.brightness = bd->ops->get_brightness(bd);
214 backlight_update_status(bd);
215 return 0;
216}
217
218int
219nouveau_backlight_init(struct drm_device *dev)
220{
221 struct nouveau_drm *drm = nouveau_drm(dev);
222 struct nouveau_device *device = nv_device(drm->device);
223 struct drm_connector *connector;
224
225#ifdef CONFIG_ACPI
226 if (acpi_video_backlight_support()) {
227 NV_INFO(drm, "ACPI backlight interface available, "
228 "not registering our own\n");
229 return 0;
230 }
231#endif
232
233 list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
234 if (connector->connector_type != DRM_MODE_CONNECTOR_LVDS &&
235 connector->connector_type != DRM_MODE_CONNECTOR_eDP)
236 continue;
237
238 switch (device->card_type) {
239 case NV_40:
240 return nv40_backlight_init(connector);
241 case NV_50:
242 case NV_C0:
243 case NV_D0:
244 case NV_E0:
245 return nv50_backlight_init(connector);
246 default:
247 break;
248 }
249 }
250
251
252 return 0;
253}
254
255void
256nouveau_backlight_exit(struct drm_device *dev)
257{
258 struct nouveau_drm *drm = nouveau_drm(dev);
259
260 if (drm->backlight) {
261 backlight_device_unregister(drm->backlight);
262 drm->backlight = NULL;
263 }
264}