| 1 | /* |
| 2 | * Copyright © 2016 Intel Corporation |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining a |
| 5 | * copy of this software and associated documentation files (the "Software"), |
| 6 | * to deal in the Software without restriction, including without limitation |
| 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| 8 | * and/or sell copies of the Software, and to permit persons to whom the |
| 9 | * Software is furnished to do so, subject to the following conditions: |
| 10 | * |
| 11 | * The above copyright notice and this permission notice shall be included in |
| 12 | * all copies or substantial portions of the Software. |
| 13 | * |
| 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 17 | * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR |
| 18 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
| 19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| 20 | * OTHER DEALINGS IN THE SOFTWARE. |
| 21 | */ |
| 22 | |
| 23 | #include <linux/errno.h> |
| 24 | #include <linux/export.h> |
| 25 | #include <linux/i2c.h> |
| 26 | #include <linux/slab.h> |
| 27 | #include <linux/string.h> |
| 28 | #include <drm/drm_dp_dual_mode_helper.h> |
| 29 | #include <drm/drmP.h> |
| 30 | |
| 31 | /** |
| 32 | * DOC: dp dual mode helpers |
| 33 | * |
| 34 | * Helper functions to deal with DP dual mode (aka. DP++) adaptors. |
| 35 | * |
| 36 | * Type 1: |
| 37 | * Adaptor registers (if any) and the sink DDC bus may be accessed via I2C. |
| 38 | * |
| 39 | * Type 2: |
| 40 | * Adaptor registers and sink DDC bus can be accessed either via I2C or |
| 41 | * I2C-over-AUX. Source devices may choose to implement either of these |
| 42 | * access methods. |
| 43 | */ |
| 44 | |
| 45 | #define DP_DUAL_MODE_SLAVE_ADDRESS 0x40 |
| 46 | |
| 47 | /** |
| 48 | * drm_dp_dual_mode_read - Read from the DP dual mode adaptor register(s) |
| 49 | * @adapter: I2C adapter for the DDC bus |
| 50 | * @offset: register offset |
| 51 | * @buffer: buffer for return data |
| 52 | * @size: sizo of the buffer |
| 53 | * |
| 54 | * Reads @size bytes from the DP dual mode adaptor registers |
| 55 | * starting at @offset. |
| 56 | * |
| 57 | * Returns: |
| 58 | * 0 on success, negative error code on failure |
| 59 | */ |
| 60 | ssize_t drm_dp_dual_mode_read(struct i2c_adapter *adapter, |
| 61 | u8 offset, void *buffer, size_t size) |
| 62 | { |
| 63 | struct i2c_msg msgs[] = { |
| 64 | { |
| 65 | .addr = DP_DUAL_MODE_SLAVE_ADDRESS, |
| 66 | .flags = 0, |
| 67 | .len = 1, |
| 68 | .buf = &offset, |
| 69 | }, |
| 70 | { |
| 71 | .addr = DP_DUAL_MODE_SLAVE_ADDRESS, |
| 72 | .flags = I2C_M_RD, |
| 73 | .len = size, |
| 74 | .buf = buffer, |
| 75 | }, |
| 76 | }; |
| 77 | int ret; |
| 78 | |
| 79 | ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs)); |
| 80 | if (ret < 0) |
| 81 | return ret; |
| 82 | if (ret != ARRAY_SIZE(msgs)) |
| 83 | return -EPROTO; |
| 84 | |
| 85 | return 0; |
| 86 | } |
| 87 | EXPORT_SYMBOL(drm_dp_dual_mode_read); |
| 88 | |
| 89 | /** |
| 90 | * drm_dp_dual_mode_write - Write to the DP dual mode adaptor register(s) |
| 91 | * @adapter: I2C adapter for the DDC bus |
| 92 | * @offset: register offset |
| 93 | * @buffer: buffer for write data |
| 94 | * @size: sizo of the buffer |
| 95 | * |
| 96 | * Writes @size bytes to the DP dual mode adaptor registers |
| 97 | * starting at @offset. |
| 98 | * |
| 99 | * Returns: |
| 100 | * 0 on success, negative error code on failure |
| 101 | */ |
| 102 | ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter, |
| 103 | u8 offset, const void *buffer, size_t size) |
| 104 | { |
| 105 | struct i2c_msg msg = { |
| 106 | .addr = DP_DUAL_MODE_SLAVE_ADDRESS, |
| 107 | .flags = 0, |
| 108 | .len = 1 + size, |
| 109 | .buf = NULL, |
| 110 | }; |
| 111 | void *data; |
| 112 | int ret; |
| 113 | |
| 114 | data = kmalloc(msg.len, GFP_KERNEL); |
| 115 | if (!data) |
| 116 | return -ENOMEM; |
| 117 | |
| 118 | msg.buf = data; |
| 119 | |
| 120 | memcpy(data, &offset, 1); |
| 121 | memcpy(data + 1, buffer, size); |
| 122 | |
| 123 | ret = i2c_transfer(adapter, &msg, 1); |
| 124 | |
| 125 | kfree(data); |
| 126 | |
| 127 | if (ret < 0) |
| 128 | return ret; |
| 129 | if (ret != 1) |
| 130 | return -EPROTO; |
| 131 | |
| 132 | return 0; |
| 133 | } |
| 134 | EXPORT_SYMBOL(drm_dp_dual_mode_write); |
| 135 | |
| 136 | static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN]) |
| 137 | { |
| 138 | static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] = |
| 139 | "DP-HDMI ADAPTOR\x04"; |
| 140 | |
| 141 | return memcmp(hdmi_id, dp_dual_mode_hdmi_id, |
| 142 | sizeof(dp_dual_mode_hdmi_id)) == 0; |
| 143 | } |
| 144 | |
| 145 | static bool is_type1_adaptor(uint8_t adaptor_id) |
| 146 | { |
| 147 | return adaptor_id == 0 || adaptor_id == 0xff; |
| 148 | } |
| 149 | |
| 150 | static bool is_type2_adaptor(uint8_t adaptor_id) |
| 151 | { |
| 152 | return adaptor_id == (DP_DUAL_MODE_TYPE_TYPE2 | |
| 153 | DP_DUAL_MODE_REV_TYPE2); |
| 154 | } |
| 155 | |
| 156 | static bool is_lspcon_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN], |
| 157 | const uint8_t adaptor_id) |
| 158 | { |
| 159 | return is_hdmi_adaptor(hdmi_id) && |
| 160 | (adaptor_id == (DP_DUAL_MODE_TYPE_TYPE2 | |
| 161 | DP_DUAL_MODE_TYPE_HAS_DPCD)); |
| 162 | } |
| 163 | |
| 164 | /** |
| 165 | * drm_dp_dual_mode_detect - Identify the DP dual mode adaptor |
| 166 | * @adapter: I2C adapter for the DDC bus |
| 167 | * |
| 168 | * Attempt to identify the type of the DP dual mode adaptor used. |
| 169 | * |
| 170 | * Note that when the answer is @DRM_DP_DUAL_MODE_UNKNOWN it's not |
| 171 | * certain whether we're dealing with a native HDMI port or |
| 172 | * a type 1 DVI dual mode adaptor. The driver will have to use |
| 173 | * some other hardware/driver specific mechanism to make that |
| 174 | * distinction. |
| 175 | * |
| 176 | * Returns: |
| 177 | * The type of the DP dual mode adaptor used |
| 178 | */ |
| 179 | enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter) |
| 180 | { |
| 181 | char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] = {}; |
| 182 | uint8_t adaptor_id = 0x00; |
| 183 | ssize_t ret; |
| 184 | |
| 185 | /* |
| 186 | * Let's see if the adaptor is there the by reading the |
| 187 | * HDMI ID registers. |
| 188 | * |
| 189 | * Note that type 1 DVI adaptors are not required to implemnt |
| 190 | * any registers, and that presents a problem for detection. |
| 191 | * If the i2c transfer is nacked, we may or may not be dealing |
| 192 | * with a type 1 DVI adaptor. Some other mechanism of detecting |
| 193 | * the presence of the adaptor is required. One way would be |
| 194 | * to check the state of the CONFIG1 pin, Another method would |
| 195 | * simply require the driver to know whether the port is a DP++ |
| 196 | * port or a native HDMI port. Both of these methods are entirely |
| 197 | * hardware/driver specific so we can't deal with them here. |
| 198 | */ |
| 199 | ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_HDMI_ID, |
| 200 | hdmi_id, sizeof(hdmi_id)); |
| 201 | DRM_DEBUG_KMS("DP dual mode HDMI ID: %*pE (err %zd)\n", |
| 202 | ret ? 0 : (int)sizeof(hdmi_id), hdmi_id, ret); |
| 203 | if (ret) |
| 204 | return DRM_DP_DUAL_MODE_UNKNOWN; |
| 205 | |
| 206 | /* |
| 207 | * Sigh. Some (maybe all?) type 1 adaptors are broken and ack |
| 208 | * the offset but ignore it, and instead they just always return |
| 209 | * data from the start of the HDMI ID buffer. So for a broken |
| 210 | * type 1 HDMI adaptor a single byte read will always give us |
| 211 | * 0x44, and for a type 1 DVI adaptor it should give 0x00 |
| 212 | * (assuming it implements any registers). Fortunately neither |
| 213 | * of those values will match the type 2 signature of the |
| 214 | * DP_DUAL_MODE_ADAPTOR_ID register so we can proceed with |
| 215 | * the type 2 adaptor detection safely even in the presence |
| 216 | * of broken type 1 adaptors. |
| 217 | */ |
| 218 | ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_ADAPTOR_ID, |
| 219 | &adaptor_id, sizeof(adaptor_id)); |
| 220 | DRM_DEBUG_KMS("DP dual mode adaptor ID: %02x (err %zd)\n", |
| 221 | adaptor_id, ret); |
| 222 | if (ret == 0) { |
| 223 | if (is_lspcon_adaptor(hdmi_id, adaptor_id)) |
| 224 | return DRM_DP_DUAL_MODE_LSPCON; |
| 225 | if (is_type2_adaptor(adaptor_id)) { |
| 226 | if (is_hdmi_adaptor(hdmi_id)) |
| 227 | return DRM_DP_DUAL_MODE_TYPE2_HDMI; |
| 228 | else |
| 229 | return DRM_DP_DUAL_MODE_TYPE2_DVI; |
| 230 | } |
| 231 | /* |
| 232 | * If neither a proper type 1 ID nor a broken type 1 adaptor |
| 233 | * as described above, assume type 1, but let the user know |
| 234 | * that we may have misdetected the type. |
| 235 | */ |
| 236 | if (!is_type1_adaptor(adaptor_id) && adaptor_id != hdmi_id[0]) |
| 237 | DRM_ERROR("Unexpected DP dual mode adaptor ID %02x\n", |
| 238 | adaptor_id); |
| 239 | |
| 240 | } |
| 241 | |
| 242 | if (is_hdmi_adaptor(hdmi_id)) |
| 243 | return DRM_DP_DUAL_MODE_TYPE1_HDMI; |
| 244 | else |
| 245 | return DRM_DP_DUAL_MODE_TYPE1_DVI; |
| 246 | } |
| 247 | EXPORT_SYMBOL(drm_dp_dual_mode_detect); |
| 248 | |
| 249 | /** |
| 250 | * drm_dp_dual_mode_max_tmds_clock - Max TMDS clock for DP dual mode adaptor |
| 251 | * @type: DP dual mode adaptor type |
| 252 | * @adapter: I2C adapter for the DDC bus |
| 253 | * |
| 254 | * Determine the max TMDS clock the adaptor supports based on the |
| 255 | * type of the dual mode adaptor and the DP_DUAL_MODE_MAX_TMDS_CLOCK |
| 256 | * register (on type2 adaptors). As some type 1 adaptors have |
| 257 | * problems with registers (see comments in drm_dp_dual_mode_detect()) |
| 258 | * we don't read the register on those, instead we simply assume |
| 259 | * a 165 MHz limit based on the specification. |
| 260 | * |
| 261 | * Returns: |
| 262 | * Maximum supported TMDS clock rate for the DP dual mode adaptor in kHz. |
| 263 | */ |
| 264 | int drm_dp_dual_mode_max_tmds_clock(enum drm_dp_dual_mode_type type, |
| 265 | struct i2c_adapter *adapter) |
| 266 | { |
| 267 | uint8_t max_tmds_clock; |
| 268 | ssize_t ret; |
| 269 | |
| 270 | /* native HDMI so no limit */ |
| 271 | if (type == DRM_DP_DUAL_MODE_NONE) |
| 272 | return 0; |
| 273 | |
| 274 | /* |
| 275 | * Type 1 adaptors are limited to 165MHz |
| 276 | * Type 2 adaptors can tells us their limit |
| 277 | */ |
| 278 | if (type < DRM_DP_DUAL_MODE_TYPE2_DVI) |
| 279 | return 165000; |
| 280 | |
| 281 | ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_MAX_TMDS_CLOCK, |
| 282 | &max_tmds_clock, sizeof(max_tmds_clock)); |
| 283 | if (ret || max_tmds_clock == 0x00 || max_tmds_clock == 0xff) { |
| 284 | DRM_DEBUG_KMS("Failed to query max TMDS clock\n"); |
| 285 | return 165000; |
| 286 | } |
| 287 | |
| 288 | return max_tmds_clock * 5000 / 2; |
| 289 | } |
| 290 | EXPORT_SYMBOL(drm_dp_dual_mode_max_tmds_clock); |
| 291 | |
| 292 | /** |
| 293 | * drm_dp_dual_mode_get_tmds_output - Get the state of the TMDS output buffers in the DP dual mode adaptor |
| 294 | * @type: DP dual mode adaptor type |
| 295 | * @adapter: I2C adapter for the DDC bus |
| 296 | * @enabled: current state of the TMDS output buffers |
| 297 | * |
| 298 | * Get the state of the TMDS output buffers in the adaptor. For |
| 299 | * type2 adaptors this is queried from the DP_DUAL_MODE_TMDS_OEN |
| 300 | * register. As some type 1 adaptors have problems with registers |
| 301 | * (see comments in drm_dp_dual_mode_detect()) we don't read the |
| 302 | * register on those, instead we simply assume that the buffers |
| 303 | * are always enabled. |
| 304 | * |
| 305 | * Returns: |
| 306 | * 0 on success, negative error code on failure |
| 307 | */ |
| 308 | int drm_dp_dual_mode_get_tmds_output(enum drm_dp_dual_mode_type type, |
| 309 | struct i2c_adapter *adapter, |
| 310 | bool *enabled) |
| 311 | { |
| 312 | uint8_t tmds_oen; |
| 313 | ssize_t ret; |
| 314 | |
| 315 | if (type < DRM_DP_DUAL_MODE_TYPE2_DVI) { |
| 316 | *enabled = true; |
| 317 | return 0; |
| 318 | } |
| 319 | |
| 320 | ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_TMDS_OEN, |
| 321 | &tmds_oen, sizeof(tmds_oen)); |
| 322 | if (ret) { |
| 323 | DRM_DEBUG_KMS("Failed to query state of TMDS output buffers\n"); |
| 324 | return ret; |
| 325 | } |
| 326 | |
| 327 | *enabled = !(tmds_oen & DP_DUAL_MODE_TMDS_DISABLE); |
| 328 | |
| 329 | return 0; |
| 330 | } |
| 331 | EXPORT_SYMBOL(drm_dp_dual_mode_get_tmds_output); |
| 332 | |
| 333 | /** |
| 334 | * drm_dp_dual_mode_set_tmds_output - Enable/disable TMDS output buffers in the DP dual mode adaptor |
| 335 | * @type: DP dual mode adaptor type |
| 336 | * @adapter: I2C adapter for the DDC bus |
| 337 | * @enable: enable (as opposed to disable) the TMDS output buffers |
| 338 | * |
| 339 | * Set the state of the TMDS output buffers in the adaptor. For |
| 340 | * type2 this is set via the DP_DUAL_MODE_TMDS_OEN register. As |
| 341 | * some type 1 adaptors have problems with registers (see comments |
| 342 | * in drm_dp_dual_mode_detect()) we avoid touching the register, |
| 343 | * making this function a no-op on type 1 adaptors. |
| 344 | * |
| 345 | * Returns: |
| 346 | * 0 on success, negative error code on failure |
| 347 | */ |
| 348 | int drm_dp_dual_mode_set_tmds_output(enum drm_dp_dual_mode_type type, |
| 349 | struct i2c_adapter *adapter, bool enable) |
| 350 | { |
| 351 | uint8_t tmds_oen = enable ? 0 : DP_DUAL_MODE_TMDS_DISABLE; |
| 352 | ssize_t ret; |
| 353 | int retry; |
| 354 | |
| 355 | if (type < DRM_DP_DUAL_MODE_TYPE2_DVI) |
| 356 | return 0; |
| 357 | |
| 358 | /* |
| 359 | * LSPCON adapters in low-power state may ignore the first write, so |
| 360 | * read back and verify the written value a few times. |
| 361 | */ |
| 362 | for (retry = 0; retry < 3; retry++) { |
| 363 | uint8_t tmp; |
| 364 | |
| 365 | ret = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_TMDS_OEN, |
| 366 | &tmds_oen, sizeof(tmds_oen)); |
| 367 | if (ret) { |
| 368 | DRM_DEBUG_KMS("Failed to %s TMDS output buffers (%d attempts)\n", |
| 369 | enable ? "enable" : "disable", |
| 370 | retry + 1); |
| 371 | return ret; |
| 372 | } |
| 373 | |
| 374 | ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_TMDS_OEN, |
| 375 | &tmp, sizeof(tmp)); |
| 376 | if (ret) { |
| 377 | DRM_DEBUG_KMS("I2C read failed during TMDS output buffer %s (%d attempts)\n", |
| 378 | enable ? "enabling" : "disabling", |
| 379 | retry + 1); |
| 380 | return ret; |
| 381 | } |
| 382 | |
| 383 | if (tmp == tmds_oen) |
| 384 | return 0; |
| 385 | } |
| 386 | |
| 387 | DRM_DEBUG_KMS("I2C write value mismatch during TMDS output buffer %s\n", |
| 388 | enable ? "enabling" : "disabling"); |
| 389 | |
| 390 | return -EIO; |
| 391 | } |
| 392 | EXPORT_SYMBOL(drm_dp_dual_mode_set_tmds_output); |
| 393 | |
| 394 | /** |
| 395 | * drm_dp_get_dual_mode_type_name - Get the name of the DP dual mode adaptor type as a string |
| 396 | * @type: DP dual mode adaptor type |
| 397 | * |
| 398 | * Returns: |
| 399 | * String representation of the DP dual mode adaptor type |
| 400 | */ |
| 401 | const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type) |
| 402 | { |
| 403 | switch (type) { |
| 404 | case DRM_DP_DUAL_MODE_NONE: |
| 405 | return "none"; |
| 406 | case DRM_DP_DUAL_MODE_TYPE1_DVI: |
| 407 | return "type 1 DVI"; |
| 408 | case DRM_DP_DUAL_MODE_TYPE1_HDMI: |
| 409 | return "type 1 HDMI"; |
| 410 | case DRM_DP_DUAL_MODE_TYPE2_DVI: |
| 411 | return "type 2 DVI"; |
| 412 | case DRM_DP_DUAL_MODE_TYPE2_HDMI: |
| 413 | return "type 2 HDMI"; |
| 414 | case DRM_DP_DUAL_MODE_LSPCON: |
| 415 | return "lspcon"; |
| 416 | default: |
| 417 | WARN_ON(type != DRM_DP_DUAL_MODE_UNKNOWN); |
| 418 | return "unknown"; |
| 419 | } |
| 420 | } |
| 421 | EXPORT_SYMBOL(drm_dp_get_dual_mode_type_name); |
| 422 | |
| 423 | /** |
| 424 | * drm_lspcon_get_mode: Get LSPCON's current mode of operation by |
| 425 | * reading offset (0x80, 0x41) |
| 426 | * @adapter: I2C-over-aux adapter |
| 427 | * @mode: current lspcon mode of operation output variable |
| 428 | * |
| 429 | * Returns: |
| 430 | * 0 on success, sets the current_mode value to appropriate mode |
| 431 | * -error on failure |
| 432 | */ |
| 433 | int drm_lspcon_get_mode(struct i2c_adapter *adapter, |
| 434 | enum drm_lspcon_mode *mode) |
| 435 | { |
| 436 | u8 data; |
| 437 | int ret = 0; |
| 438 | int retry; |
| 439 | |
| 440 | if (!mode) { |
| 441 | DRM_ERROR("NULL input\n"); |
| 442 | return -EINVAL; |
| 443 | } |
| 444 | |
| 445 | /* Read Status: i2c over aux */ |
| 446 | for (retry = 0; retry < 6; retry++) { |
| 447 | if (retry) |
| 448 | usleep_range(500, 1000); |
| 449 | |
| 450 | ret = drm_dp_dual_mode_read(adapter, |
| 451 | DP_DUAL_MODE_LSPCON_CURRENT_MODE, |
| 452 | &data, sizeof(data)); |
| 453 | if (!ret) |
| 454 | break; |
| 455 | } |
| 456 | |
| 457 | if (ret < 0) { |
| 458 | DRM_DEBUG_KMS("LSPCON read(0x80, 0x41) failed\n"); |
| 459 | return -EFAULT; |
| 460 | } |
| 461 | |
| 462 | if (data & DP_DUAL_MODE_LSPCON_MODE_PCON) |
| 463 | *mode = DRM_LSPCON_MODE_PCON; |
| 464 | else |
| 465 | *mode = DRM_LSPCON_MODE_LS; |
| 466 | return 0; |
| 467 | } |
| 468 | EXPORT_SYMBOL(drm_lspcon_get_mode); |
| 469 | |
| 470 | /** |
| 471 | * drm_lspcon_set_mode: Change LSPCON's mode of operation by |
| 472 | * writing offset (0x80, 0x40) |
| 473 | * @adapter: I2C-over-aux adapter |
| 474 | * @mode: required mode of operation |
| 475 | * |
| 476 | * Returns: |
| 477 | * 0 on success, -error on failure/timeout |
| 478 | */ |
| 479 | int drm_lspcon_set_mode(struct i2c_adapter *adapter, |
| 480 | enum drm_lspcon_mode mode) |
| 481 | { |
| 482 | u8 data = 0; |
| 483 | int ret; |
| 484 | int time_out = 200; |
| 485 | enum drm_lspcon_mode current_mode; |
| 486 | |
| 487 | if (mode == DRM_LSPCON_MODE_PCON) |
| 488 | data = DP_DUAL_MODE_LSPCON_MODE_PCON; |
| 489 | |
| 490 | /* Change mode */ |
| 491 | ret = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_LSPCON_MODE_CHANGE, |
| 492 | &data, sizeof(data)); |
| 493 | if (ret < 0) { |
| 494 | DRM_ERROR("LSPCON mode change failed\n"); |
| 495 | return ret; |
| 496 | } |
| 497 | |
| 498 | /* |
| 499 | * Confirm mode change by reading the status bit. |
| 500 | * Sometimes, it takes a while to change the mode, |
| 501 | * so wait and retry until time out or done. |
| 502 | */ |
| 503 | do { |
| 504 | ret = drm_lspcon_get_mode(adapter, ¤t_mode); |
| 505 | if (ret) { |
| 506 | DRM_ERROR("can't confirm LSPCON mode change\n"); |
| 507 | return ret; |
| 508 | } else { |
| 509 | if (current_mode != mode) { |
| 510 | msleep(10); |
| 511 | time_out -= 10; |
| 512 | } else { |
| 513 | DRM_DEBUG_KMS("LSPCON mode changed to %s\n", |
| 514 | mode == DRM_LSPCON_MODE_LS ? |
| 515 | "LS" : "PCON"); |
| 516 | return 0; |
| 517 | } |
| 518 | } |
| 519 | } while (time_out); |
| 520 | |
| 521 | DRM_ERROR("LSPCON mode change timed out\n"); |
| 522 | return -ETIMEDOUT; |
| 523 | } |
| 524 | EXPORT_SYMBOL(drm_lspcon_set_mode); |