40  * levels to deal with Display Port sink devices and related things like DP aux
41  * channel transfers, EDID reading over DP aux channels, decoding certain DPCD
126 		DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n",  in drm_dp_link_train_clock_recovery_delay()
141 		DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n",  in drm_dp_link_train_channel_eq_delay()
189 drm_dp_dump_access(const struct drm_dp_aux *aux,  in drm_dp_dump_access()  argument
195 		drm_dbg(DRM_UT_DP, "%s: 0x%05x AUX %s (ret=%3d) %*ph\n",  in drm_dp_dump_access()
196 			aux->name, offset, arrow, ret, min(ret, 20), buffer);  in drm_dp_dump_access()
198 		drm_dbg(DRM_UT_DP, "%s: 0x%05x AUX %s (ret=%3d)\n",  in drm_dp_dump_access()
199 			aux->name, offset, arrow, ret);  in drm_dp_dump_access()
205  * The DisplayPort AUX channel is an abstraction to allow generic, driver-
206  * independent access to AUX functionality. Drivers can take advantage of
211  * Both native and I2C-over-AUX transactions are supported.
214 static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,  in drm_dp_dpcd_access()  argument
227 	mutex_lock(&aux->hw_mutex);  in drm_dp_dpcd_access()
232 	 * aux i2c transactions but real world devices this wasn't  in drm_dp_dpcd_access()
241 		ret = aux->transfer(aux, &msg);  in drm_dp_dpcd_access()
267 	mutex_unlock(&aux->hw_mutex);  in drm_dp_dpcd_access()
273  * @aux: DisplayPort AUX channel
281  * function returns -EPROTO. Errors from the underlying AUX channel transfer
285 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,  in drm_dp_dpcd_read()  argument
302 	ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer,  in drm_dp_dpcd_read()
307 	ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer,  in drm_dp_dpcd_read()
311 	drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, buffer, ret);  in drm_dp_dpcd_read()
318  * @aux: DisplayPort AUX channel
326  * function returns -EPROTO. Errors from the underlying AUX channel transfer
330 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,  in drm_dp_dpcd_write()  argument
335 	ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer,  in drm_dp_dpcd_write()
337 	drm_dp_dump_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, ret);  in drm_dp_dpcd_write()
344  * @aux: DisplayPort AUX channel
350 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,  in drm_dp_dpcd_read_link_status()  argument
353 	return drm_dp_dpcd_read(aux, DP_LANE0_1_STATUS, status,  in drm_dp_dpcd_read_link_status()
360  * @aux: DisplayPort AUX channel
369 int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)  in drm_dp_link_probe()  argument
376 	err = drm_dp_dpcd_read(aux, DP_DPCD_REV, values, sizeof(values));  in drm_dp_link_probe()
393  * @aux: DisplayPort AUX channel
398 int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link)  in drm_dp_link_power_up()  argument
407 	err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);  in drm_dp_link_power_up()
414 	err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);  in drm_dp_link_power_up()
431  * @aux: DisplayPort AUX channel
436 int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link)  in drm_dp_link_power_down()  argument
445 	err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);  in drm_dp_link_power_down()
452 	err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);  in drm_dp_link_power_down()
462  * @aux: DisplayPort AUX channel
467 int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)  in drm_dp_link_configure()  argument
478 	err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, values, sizeof(values));  in drm_dp_link_configure()
563  * @aux: DisplayPort AUX channel
568 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6])  in drm_dp_downstream_id()  argument
570 	return drm_dp_dpcd_read(aux, DP_BRANCH_ID, id, 6);  in drm_dp_downstream_id()
579  * @aux: DisplayPort AUX channel
584 			     const u8 port_cap[4], struct drm_dp_aux *aux)  in drm_dp_downstream_debug()  argument
630 	drm_dp_downstream_id(aux, id);  in drm_dp_downstream_debug()
633 	len = drm_dp_dpcd_read(aux, DP_BRANCH_HW_REV, &rev[0], 1);  in drm_dp_downstream_debug()
638 	len = drm_dp_dpcd_read(aux, DP_BRANCH_SW_REV, rev, 2);  in drm_dp_downstream_debug()
661  * I2C-over-AUX implementation
694  * Calculate the duration of the AUX request/reply in usec. Gives the
739 	/* AUX bitrate is 1MHz, i2c bitrate as specified */  in drm_dp_i2c_msg_duration()
748  * i2c and AUX transfers.
770  * Transfer a single I2C-over-AUX message and handle various error conditions,
777 static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)  in drm_dp_i2c_do_msg()  argument
784 	 * before giving up the AUX transaction.  in drm_dp_i2c_do_msg()
791 		ret = aux->transfer(aux, msg);  in drm_dp_i2c_do_msg()
814 			 * For I2C-over-AUX transactions this isn't enough, we  in drm_dp_i2c_do_msg()
854 			aux->i2c_nack_count++;  in drm_dp_i2c_do_msg()
863 			aux->i2c_defer_count++;  in drm_dp_i2c_do_msg()
894 static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *orig_msg)  in drm_dp_i2c_drain_msg()  argument
900 		err = drm_dp_i2c_do_msg(aux, &msg);  in drm_dp_i2c_drain_msg()
918  * Bizlink designed DP->DVI-D Dual Link adapters require the I2C over AUX
925 		 "Number of bytes to transfer in a single I2C over DP AUX CH message, (1-16, default 16)");
930 	struct drm_dp_aux *aux = adapter->algo_data;  in drm_dp_i2c_xfer()  local
949 		err = drm_dp_i2c_do_msg(aux, &msg);  in drm_dp_i2c_xfer()
968 			err = drm_dp_i2c_drain_msg(aux, &msg);  in drm_dp_i2c_xfer()
992 	(void)drm_dp_i2c_do_msg(aux, &msg);  in drm_dp_i2c_xfer()
1028 static int drm_dp_aux_get_crc(struct drm_dp_aux *aux, u8 *crc)  in drm_dp_aux_get_crc()  argument
1033 	ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);  in drm_dp_aux_get_crc()
1039 	ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK_MISC, &buf);  in drm_dp_aux_get_crc()
1044 	if (count == aux->crc_count)  in drm_dp_aux_get_crc()
1047 	aux->crc_count = count;  in drm_dp_aux_get_crc()
1053 	ret = drm_dp_dpcd_read(aux, DP_TEST_CRC_R_CR, crc, 6);  in drm_dp_aux_get_crc()
1062 	struct drm_dp_aux *aux = container_of(work, struct drm_dp_aux,  in drm_dp_aux_crc_work()  local
1069 	if (WARN_ON(!aux->crtc))  in drm_dp_aux_crc_work()
1072 	crtc = aux->crtc;  in drm_dp_aux_crc_work()
1078 		ret = drm_dp_aux_get_crc(aux, crc_bytes);  in drm_dp_aux_crc_work()
1081 			ret = drm_dp_aux_get_crc(aux, crc_bytes);  in drm_dp_aux_crc_work()
1101  * drm_dp_aux_init() - minimally initialise an aux channel
1102  * @aux: DisplayPort AUX channel
1109 void drm_dp_aux_init(struct drm_dp_aux *aux)  in drm_dp_aux_init()  argument
1111 	mutex_init(&aux->hw_mutex);  in drm_dp_aux_init()
1112 	mutex_init(&aux->cec.lock);  in drm_dp_aux_init()
1113 	INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work);  in drm_dp_aux_init()
1115 	aux->ddc.algo = &drm_dp_i2c_algo;  in drm_dp_aux_init()
1116 	aux->ddc.algo_data = aux;  in drm_dp_aux_init()
1117 	aux->ddc.retries = 3;  in drm_dp_aux_init()
1119 	aux->ddc.lock_ops = &drm_dp_i2c_lock_ops;  in drm_dp_aux_init()
1124  * drm_dp_aux_register() - initialise and register aux channel
1125  * @aux: DisplayPort AUX channel
1131 int drm_dp_aux_register(struct drm_dp_aux *aux)  in drm_dp_aux_register()  argument
1135 	if (!aux->ddc.algo)  in drm_dp_aux_register()
1136 		drm_dp_aux_init(aux);  in drm_dp_aux_register()
1138 	aux->ddc.class = I2C_CLASS_DDC;  in drm_dp_aux_register()
1139 	aux->ddc.owner = THIS_MODULE;  in drm_dp_aux_register()
1140 	aux->ddc.dev.parent = aux->dev;  in drm_dp_aux_register()
1142 	strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),  in drm_dp_aux_register()
1143 		sizeof(aux->ddc.name));  in drm_dp_aux_register()
1145 	ret = drm_dp_aux_register_devnode(aux);  in drm_dp_aux_register()
1149 	ret = i2c_add_adapter(&aux->ddc);  in drm_dp_aux_register()
1151 		drm_dp_aux_unregister_devnode(aux);  in drm_dp_aux_register()
1160  * drm_dp_aux_unregister() - unregister an AUX adapter
1161  * @aux: DisplayPort AUX channel
1163 void drm_dp_aux_unregister(struct drm_dp_aux *aux)  in drm_dp_aux_unregister()  argument
1165 	drm_dp_aux_unregister_devnode(aux);  in drm_dp_aux_unregister()
1166 	i2c_del_adapter(&aux->ddc);  in drm_dp_aux_unregister()
1205  * @aux: DisplayPort AUX channel
1210 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc)  in drm_dp_start_crc()  argument
1215 	ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);  in drm_dp_start_crc()
1219 	ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf | DP_TEST_SINK_START);  in drm_dp_start_crc()
1223 	aux->crc_count = 0;  in drm_dp_start_crc()
1224 	aux->crtc = crtc;  in drm_dp_start_crc()
1225 	schedule_work(&aux->crc_work);  in drm_dp_start_crc()
1233  * @aux: DisplayPort AUX channel
1237 int drm_dp_stop_crc(struct drm_dp_aux *aux)  in drm_dp_stop_crc()  argument
1242 	ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);  in drm_dp_stop_crc()
1246 	ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf & ~DP_TEST_SINK_START);  in drm_dp_stop_crc()
1250 	flush_work(&aux->crc_work);  in drm_dp_stop_crc()
1251 	aux->crtc = NULL;  in drm_dp_stop_crc()
1304  * @aux: DisplayPort AUX channel
1313 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,  in drm_dp_read_desc()  argument
1320 	ret = drm_dp_dpcd_read(aux, offset, ident, sizeof(*ident));  in drm_dp_read_desc()