diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 2371 |
1 files changed, 2371 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c new file mode 100644 index 000000000..6ba16db77 --- /dev/null +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -0,0 +1,2371 @@ +/* + * Copyright © 2009 Keith Packard + * + * Permission to use, copy, modify, distribute, and sell this software and its + * documentation for any purpose is hereby granted without fee, provided that + * the above copyright notice appear in all copies and that both that copyright + * notice and this permission notice appear in supporting documentation, and + * that the name of the copyright holders not be used in advertising or + * publicity pertaining to distribution of the software without specific, + * written prior permission. The copyright holders make no representations + * about the suitability of this software for any purpose. It is provided "as + * is" without express or implied warranty. + * + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE + * OF THIS SOFTWARE. + */ + +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/seq_file.h> + +#include <drm/drm_dp_helper.h> +#include <drm/drm_print.h> +#include <drm/drm_vblank.h> +#include <drm/drm_dp_mst_helper.h> + +#include "drm_crtc_helper_internal.h" + +/** + * DOC: dp helpers + * + * These functions contain some common logic and helpers at various abstraction + * levels to deal with Display Port sink devices and related things like DP aux + * channel transfers, EDID reading over DP aux channels, decoding certain DPCD + * blocks, ... + */ + +/* Helpers for DP link training */ +static u8 dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r) +{ + return link_status[r - DP_LANE0_1_STATUS]; +} + +static u8 dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_LANE0_1_STATUS + (lane >> 1); + int s = (lane & 1) * 4; + u8 l = dp_link_status(link_status, i); + + return (l >> s) & 0xf; +} + +bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + u8 lane_align; + u8 lane_status; + int lane; + + lane_align = dp_link_status(link_status, + DP_LANE_ALIGN_STATUS_UPDATED); + if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0) + return false; + for (lane = 0; lane < lane_count; lane++) { + lane_status = dp_get_lane_status(link_status, lane); + if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS) + return false; + } + return true; +} +EXPORT_SYMBOL(drm_dp_channel_eq_ok); + +bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + int lane; + u8 lane_status; + + for (lane = 0; lane < lane_count; lane++) { + lane_status = dp_get_lane_status(link_status, lane); + if ((lane_status & DP_LANE_CR_DONE) == 0) + return false; + } + return true; +} +EXPORT_SYMBOL(drm_dp_clock_recovery_ok); + +u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); + int s = ((lane & 1) ? + DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT : + DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT); + u8 l = dp_link_status(link_status, i); + + return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT; +} +EXPORT_SYMBOL(drm_dp_get_adjust_request_voltage); + +u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); + int s = ((lane & 1) ? + DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT : + DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT); + u8 l = dp_link_status(link_status, i); + + return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT; +} +EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis); + +u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZE], + unsigned int lane) +{ + unsigned int offset = DP_ADJUST_REQUEST_POST_CURSOR2; + u8 value = dp_link_status(link_status, offset); + + return (value >> (lane << 1)) & 0x3; +} +EXPORT_SYMBOL(drm_dp_get_adjust_request_post_cursor); + +void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + unsigned long rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_TRAINING_AUX_RD_MASK; + + if (rd_interval > 4) + DRM_DEBUG_KMS("AUX interval %lu, out of range (max 4)\n", + rd_interval); + + if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) + rd_interval = 100; + else + rd_interval *= 4 * USEC_PER_MSEC; + + usleep_range(rd_interval, rd_interval * 2); +} +EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay); + +void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + unsigned long rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_TRAINING_AUX_RD_MASK; + + if (rd_interval > 4) + DRM_DEBUG_KMS("AUX interval %lu, out of range (max 4)\n", + rd_interval); + + if (rd_interval == 0) + rd_interval = 400; + else + rd_interval *= 4 * USEC_PER_MSEC; + + usleep_range(rd_interval, rd_interval * 2); +} +EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay); + +u8 drm_dp_link_rate_to_bw_code(int link_rate) +{ + /* Spec says link_bw = link_rate / 0.27Gbps */ + return link_rate / 27000; +} +EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code); + +int drm_dp_bw_code_to_link_rate(u8 link_bw) +{ + /* Spec says link_rate = link_bw * 0.27Gbps */ + return link_bw * 27000; +} +EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate); + +#define AUX_RETRY_INTERVAL 500 /* us */ + +static inline void +drm_dp_dump_access(const struct drm_dp_aux *aux, + u8 request, uint offset, void *buffer, int ret) +{ + const char *arrow = request == DP_AUX_NATIVE_READ ? "->" : "<-"; + + if (ret > 0) + DRM_DEBUG_DP("%s: 0x%05x AUX %s (ret=%3d) %*ph\n", + aux->name, offset, arrow, ret, min(ret, 20), buffer); + else + DRM_DEBUG_DP("%s: 0x%05x AUX %s (ret=%3d)\n", + aux->name, offset, arrow, ret); +} + +/** + * DOC: dp helpers + * + * The DisplayPort AUX channel is an abstraction to allow generic, driver- + * independent access to AUX functionality. Drivers can take advantage of + * this by filling in the fields of the drm_dp_aux structure. + * + * Transactions are described using a hardware-independent drm_dp_aux_msg + * structure, which is passed into a driver's .transfer() implementation. + * Both native and I2C-over-AUX transactions are supported. + */ + +static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, + unsigned int offset, void *buffer, size_t size) +{ + struct drm_dp_aux_msg msg; + unsigned int retry, native_reply; + int err = 0, ret = 0; + + memset(&msg, 0, sizeof(msg)); + msg.address = offset; + msg.request = request; + msg.buffer = buffer; + msg.size = size; + + mutex_lock(&aux->hw_mutex); + + /* + * The specification doesn't give any recommendation on how often to + * retry native transactions. We used to retry 7 times like for + * aux i2c transactions but real world devices this wasn't + * sufficient, bump to 32 which makes Dell 4k monitors happier. + */ + for (retry = 0; retry < 32; retry++) { + if (ret != 0 && ret != -ETIMEDOUT) { + usleep_range(AUX_RETRY_INTERVAL, + AUX_RETRY_INTERVAL + 100); + } + + ret = aux->transfer(aux, &msg); + if (ret >= 0) { + native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK; + if (native_reply == DP_AUX_NATIVE_REPLY_ACK) { + if (ret == size) + goto unlock; + + ret = -EPROTO; + } else + ret = -EIO; + } + + /* + * We want the error we return to be the error we received on + * the first transaction, since we may get a different error the + * next time we retry + */ + if (!err) + err = ret; + } + + DRM_DEBUG_KMS("%s: Too many retries, giving up. First error: %d\n", + aux->name, err); + ret = err; + +unlock: + mutex_unlock(&aux->hw_mutex); + return ret; +} + +/** + * drm_dp_dpcd_read() - read a series of bytes from the DPCD + * @aux: DisplayPort AUX channel (SST or MST) + * @offset: address of the (first) register to read + * @buffer: buffer to store the register values + * @size: number of bytes in @buffer + * + * Returns the number of bytes transferred on success, or a negative error + * code on failure. -EIO is returned if the request was NAKed by the sink or + * if the retry count was exceeded. If not all bytes were transferred, this + * function returns -EPROTO. Errors from the underlying AUX channel transfer + * function, with the exception of -EBUSY (which causes the transaction to + * be retried), are propagated to the caller. + */ +ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, + void *buffer, size_t size) +{ + int ret; + + /* + * HP ZR24w corrupts the first DPCD access after entering power save + * mode. Eg. on a read, the entire buffer will be filled with the same + * byte. Do a throw away read to avoid corrupting anything we care + * about. Afterwards things will work correctly until the monitor + * gets woken up and subsequently re-enters power save mode. + * + * The user pressing any button on the monitor is enough to wake it + * up, so there is no particularly good place to do the workaround. + * We just have to do it before any DPCD access and hope that the + * monitor doesn't power down exactly after the throw away read. + */ + if (!aux->is_remote) { + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, + buffer, 1); + if (ret != 1) + goto out; + } + + if (aux->is_remote) + ret = drm_dp_mst_dpcd_read(aux, offset, buffer, size); + else + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, + buffer, size); + +out: + drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, buffer, ret); + return ret; +} +EXPORT_SYMBOL(drm_dp_dpcd_read); + +/** + * drm_dp_dpcd_write() - write a series of bytes to the DPCD + * @aux: DisplayPort AUX channel (SST or MST) + * @offset: address of the (first) register to write + * @buffer: buffer containing the values to write + * @size: number of bytes in @buffer + * + * Returns the number of bytes transferred on success, or a negative error + * code on failure. -EIO is returned if the request was NAKed by the sink or + * if the retry count was exceeded. If not all bytes were transferred, this + * function returns -EPROTO. Errors from the underlying AUX channel transfer + * function, with the exception of -EBUSY (which causes the transaction to + * be retried), are propagated to the caller. + */ +ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, + void *buffer, size_t size) +{ + int ret; + + if (aux->is_remote) + ret = drm_dp_mst_dpcd_write(aux, offset, buffer, size); + else + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset, + buffer, size); + + drm_dp_dump_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, ret); + return ret; +} +EXPORT_SYMBOL(drm_dp_dpcd_write); + +/** + * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207) + * @aux: DisplayPort AUX channel + * @status: buffer to store the link status in (must be at least 6 bytes) + * + * Returns the number of bytes transferred on success or a negative error + * code on failure. + */ +int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, + u8 status[DP_LINK_STATUS_SIZE]) +{ + return drm_dp_dpcd_read(aux, DP_LANE0_1_STATUS, status, + DP_LINK_STATUS_SIZE); +} +EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); + +static bool is_edid_digital_input_dp(const struct edid *edid) +{ + return edid && edid->revision >= 4 && + edid->input & DRM_EDID_INPUT_DIGITAL && + (edid->input & DRM_EDID_DIGITAL_TYPE_MASK) == DRM_EDID_DIGITAL_TYPE_DP; +} + +/** + * drm_dp_downstream_is_type() - is the downstream facing port of certain type? + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @type: port type to be checked. Can be: + * %DP_DS_PORT_TYPE_DP, %DP_DS_PORT_TYPE_VGA, %DP_DS_PORT_TYPE_DVI, + * %DP_DS_PORT_TYPE_HDMI, %DP_DS_PORT_TYPE_NON_EDID, + * %DP_DS_PORT_TYPE_DP_DUALMODE or %DP_DS_PORT_TYPE_WIRELESS. + * + * Caveat: Only works with DPCD 1.1+ port caps. + * + * Returns: whether the downstream facing port matches the type. + */ +bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], u8 type) +{ + return drm_dp_is_branch(dpcd) && + dpcd[DP_DPCD_REV] >= 0x11 && + (port_cap[0] & DP_DS_PORT_TYPE_MASK) == type; +} +EXPORT_SYMBOL(drm_dp_downstream_is_type); + +/** + * drm_dp_downstream_is_tmds() - is the downstream facing port TMDS? + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @edid: EDID + * + * Returns: whether the downstream facing port is TMDS (HDMI/DVI). + */ +bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct edid *edid) +{ + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + return true; + default: + return false; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(edid)) + return false; + fallthrough; + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_HDMI: + return true; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_is_tmds); + +/** + * drm_dp_send_real_edid_checksum() - send back real edid checksum value + * @aux: DisplayPort AUX channel + * @real_edid_checksum: real edid checksum for the last block + * + * Returns: + * True on success + */ +bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, + u8 real_edid_checksum) +{ + u8 link_edid_read = 0, auto_test_req = 0, test_resp = 0; + + if (drm_dp_dpcd_read(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, + &auto_test_req, 1) < 1) { + DRM_ERROR("%s: DPCD failed read at register 0x%x\n", + aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR); + return false; + } + auto_test_req &= DP_AUTOMATED_TEST_REQUEST; + + if (drm_dp_dpcd_read(aux, DP_TEST_REQUEST, &link_edid_read, 1) < 1) { + DRM_ERROR("%s: DPCD failed read at register 0x%x\n", + aux->name, DP_TEST_REQUEST); + return false; + } + link_edid_read &= DP_TEST_LINK_EDID_READ; + + if (!auto_test_req || !link_edid_read) { + DRM_DEBUG_KMS("%s: Source DUT does not support TEST_EDID_READ\n", + aux->name); + return false; + } + + if (drm_dp_dpcd_write(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, + &auto_test_req, 1) < 1) { + DRM_ERROR("%s: DPCD failed write at register 0x%x\n", + aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR); + return false; + } + + /* send back checksum for the last edid extension block data */ + if (drm_dp_dpcd_write(aux, DP_TEST_EDID_CHECKSUM, + &real_edid_checksum, 1) < 1) { + DRM_ERROR("%s: DPCD failed write at register 0x%x\n", + aux->name, DP_TEST_EDID_CHECKSUM); + return false; + } + + test_resp |= DP_TEST_EDID_CHECKSUM_WRITE; + if (drm_dp_dpcd_write(aux, DP_TEST_RESPONSE, &test_resp, 1) < 1) { + DRM_ERROR("%s: DPCD failed write at register 0x%x\n", + aux->name, DP_TEST_RESPONSE); + return false; + } + + return true; +} +EXPORT_SYMBOL(drm_dp_send_real_edid_checksum); + +static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 port_count = dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_PORT_COUNT_MASK; + + if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE && port_count > 4) + port_count = 4; + + return port_count; +} + +static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux, + u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 dpcd_ext[6]; + int ret; + + /* + * Prior to DP1.3 the bit represented by + * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved. + * If it is set DP_DPCD_REV at 0000h could be at a value less than + * the true capability of the panel. The only way to check is to + * then compare 0000h and 2200h. + */ + if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT)) + return 0; + + ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, &dpcd_ext, + sizeof(dpcd_ext)); + if (ret < 0) + return ret; + if (ret != sizeof(dpcd_ext)) + return -EIO; + + if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) { + DRM_DEBUG_KMS("%s: Extended DPCD rev less than base DPCD rev (%d > %d)\n", + aux->name, dpcd[DP_DPCD_REV], + dpcd_ext[DP_DPCD_REV]); + return 0; + } + + if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext))) + return 0; + + DRM_DEBUG_KMS("%s: Base DPCD: %*ph\n", + aux->name, DP_RECEIVER_CAP_SIZE, dpcd); + + memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext)); + + return 0; +} + +/** + * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if + * available + * @aux: DisplayPort AUX channel + * @dpcd: Buffer to store the resulting DPCD in + * + * Attempts to read the base DPCD caps for @aux. Additionally, this function + * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if + * present. + * + * Returns: %0 if the DPCD was read successfully, negative error code + * otherwise. + */ +int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux, + u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + int ret; + + ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE); + if (ret < 0) + return ret; + if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0) + return -EIO; + + ret = drm_dp_read_extended_dpcd_caps(aux, dpcd); + if (ret < 0) + return ret; + + DRM_DEBUG_KMS("%s: DPCD: %*ph\n", + aux->name, DP_RECEIVER_CAP_SIZE, dpcd); + + return ret; +} +EXPORT_SYMBOL(drm_dp_read_dpcd_caps); + +/** + * drm_dp_read_downstream_info() - read DPCD downstream port info if available + * @aux: DisplayPort AUX channel + * @dpcd: A cached copy of the port's DPCD + * @downstream_ports: buffer to store the downstream port info in + * + * See also: + * drm_dp_downstream_max_clock() + * drm_dp_downstream_max_bpc() + * + * Returns: 0 if either the downstream port info was read successfully or + * there was no downstream info to read, or a negative error code otherwise. + */ +int drm_dp_read_downstream_info(struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]) +{ + int ret; + u8 len; + + memset(downstream_ports, 0, DP_MAX_DOWNSTREAM_PORTS); + + /* No downstream info to read */ + if (!drm_dp_is_branch(dpcd) || + dpcd[DP_DPCD_REV] < DP_DPCD_REV_10 || + !(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT)) + return 0; + + /* Some branches advertise having 0 downstream ports, despite also advertising they have a + * downstream port present. The DP spec isn't clear on if this is allowed or not, but since + * some branches do it we need to handle it regardless. + */ + len = drm_dp_downstream_port_count(dpcd); + if (!len) + return 0; + + if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) + len *= 4; + + ret = drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len); + if (ret < 0) + return ret; + if (ret != len) + return -EIO; + + DRM_DEBUG_KMS("%s: DPCD DFP: %*ph\n", + aux->name, len, downstream_ports); + + return 0; +} +EXPORT_SYMBOL(drm_dp_read_downstream_info); + +/** + * drm_dp_downstream_max_dotclock() - extract downstream facing port max dot clock + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Returns: Downstream facing port max dot clock in kHz on success, + * or 0 if max clock not defined + */ +int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + if (!drm_dp_is_branch(dpcd)) + return 0; + + if (dpcd[DP_DPCD_REV] < 0x11) + return 0; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_VGA: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 0; + return port_cap[1] * 8000; + default: + return 0; + } +} +EXPORT_SYMBOL(drm_dp_downstream_max_dotclock); + +/** + * drm_dp_downstream_max_tmds_clock() - extract downstream facing port max TMDS clock + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @edid: EDID + * + * Returns: HDMI/DVI downstream facing port max TMDS clock in kHz on success, + * or 0 if max TMDS clock not defined + */ +int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct edid *edid) +{ + if (!drm_dp_is_branch(dpcd)) + return 0; + + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + return 165000; + default: + return 0; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(edid)) + return 0; + /* + * It's left up to the driver to check the + * DP dual mode adapter's max TMDS clock. + * + * Unfortunatley it looks like branch devices + * may not fordward that the DP dual mode i2c + * access so we just usually get i2c nak :( + */ + fallthrough; + case DP_DS_PORT_TYPE_HDMI: + /* + * We should perhaps assume 165 MHz when detailed cap + * info is not available. But looks like many typical + * branch devices fall into that category and so we'd + * probably end up with users complaining that they can't + * get high resolution modes with their favorite dongle. + * + * So let's limit to 300 MHz instead since DPCD 1.4 + * HDMI 2.0 DFPs are required to have the detailed cap + * info. So it's more likely we're dealing with a HDMI 1.4 + * compatible* device here. + */ + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 300000; + return port_cap[1] * 2500; + case DP_DS_PORT_TYPE_DVI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 165000; + /* FIXME what to do about DVI dual link? */ + return port_cap[1] * 2500; + default: + return 0; + } +} +EXPORT_SYMBOL(drm_dp_downstream_max_tmds_clock); + +/** + * drm_dp_downstream_min_tmds_clock() - extract downstream facing port min TMDS clock + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @edid: EDID + * + * Returns: HDMI/DVI downstream facing port min TMDS clock in kHz on success, + * or 0 if max TMDS clock not defined + */ +int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct edid *edid) +{ + if (!drm_dp_is_branch(dpcd)) + return 0; + + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + return 25000; + default: + return 0; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(edid)) + return 0; + fallthrough; + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_HDMI: + /* + * Unclear whether the protocol converter could + * utilize pixel replication. Assume it won't. + */ + return 25000; + default: + return 0; + } +} +EXPORT_SYMBOL(drm_dp_downstream_min_tmds_clock); + +/** + * drm_dp_downstream_max_bpc() - extract downstream facing port max + * bits per component + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * @edid: EDID + * + * Returns: Max bpc on success or 0 if max bpc not defined + */ +int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct edid *edid) +{ + if (!drm_dp_is_branch(dpcd)) + return 0; + + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_DP: + return 0; + default: + return 8; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP: + return 0; + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(edid)) + return 0; + fallthrough; + case DP_DS_PORT_TYPE_HDMI: + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_VGA: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 8; + + switch (port_cap[2] & DP_DS_MAX_BPC_MASK) { + case DP_DS_8BPC: + return 8; + case DP_DS_10BPC: + return 10; + case DP_DS_12BPC: + return 12; + case DP_DS_16BPC: + return 16; + default: + return 8; + } + break; + default: + return 8; + } +} +EXPORT_SYMBOL(drm_dp_downstream_max_bpc); + +/** + * drm_dp_downstream_420_passthrough() - determine downstream facing port + * YCbCr 4:2:0 pass-through capability + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * + * Returns: whether the downstream facing port can pass through YCbCr 4:2:0 + */ +bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + if (!drm_dp_is_branch(dpcd)) + return false; + + if (dpcd[DP_DPCD_REV] < 0x13) + return false; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP: + return true; + case DP_DS_PORT_TYPE_HDMI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return false; + + return port_cap[3] & DP_DS_HDMI_YCBCR420_PASS_THROUGH; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_420_passthrough); + +/** + * drm_dp_downstream_444_to_420_conversion() - determine downstream facing port + * YCbCr 4:4:4->4:2:0 conversion capability + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * + * Returns: whether the downstream facing port can convert YCbCr 4:4:4 to 4:2:0 + */ +bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + if (!drm_dp_is_branch(dpcd)) + return false; + + if (dpcd[DP_DPCD_REV] < 0x13) + return false; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_HDMI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return false; + + return port_cap[3] & DP_DS_HDMI_YCBCR444_TO_420_CONV; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_444_to_420_conversion); + +/** + * drm_dp_downstream_mode() - return a mode for downstream facing port + * @dev: DRM device + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Provides a suitable mode for downstream facing ports without EDID. + * + * Returns: A new drm_display_mode on success or NULL on failure + */ +struct drm_display_mode * +drm_dp_downstream_mode(struct drm_device *dev, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) + +{ + u8 vic; + + if (!drm_dp_is_branch(dpcd)) + return NULL; + + if (dpcd[DP_DPCD_REV] < 0x11) + return NULL; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_NON_EDID: + switch (port_cap[0] & DP_DS_NON_EDID_MASK) { + case DP_DS_NON_EDID_720x480i_60: + vic = 6; + break; + case DP_DS_NON_EDID_720x480i_50: + vic = 21; + break; + case DP_DS_NON_EDID_1920x1080i_60: + vic = 5; + break; + case DP_DS_NON_EDID_1920x1080i_50: + vic = 20; + break; + case DP_DS_NON_EDID_1280x720_60: + vic = 4; + break; + case DP_DS_NON_EDID_1280x720_50: + vic = 19; + break; + default: + return NULL; + } + return drm_display_mode_from_cea_vic(dev, vic); + default: + return NULL; + } +} +EXPORT_SYMBOL(drm_dp_downstream_mode); + +/** + * drm_dp_downstream_id() - identify branch device + * @aux: DisplayPort AUX channel + * @id: DisplayPort branch device id + * + * Returns branch device id on success or NULL on failure + */ +int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]) +{ + return drm_dp_dpcd_read(aux, DP_BRANCH_ID, id, 6); +} +EXPORT_SYMBOL(drm_dp_downstream_id); + +/** + * drm_dp_downstream_debug() - debug DP branch devices + * @m: pointer for debugfs file + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @edid: EDID + * @aux: DisplayPort AUX channel + * + */ +void drm_dp_downstream_debug(struct seq_file *m, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct edid *edid, + struct drm_dp_aux *aux) +{ + bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & + DP_DETAILED_CAP_INFO_AVAILABLE; + int clk; + int bpc; + char id[7]; + int len; + uint8_t rev[2]; + int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; + bool branch_device = drm_dp_is_branch(dpcd); + + seq_printf(m, "\tDP branch device present: %s\n", + branch_device ? "yes" : "no"); + + if (!branch_device) + return; + + switch (type) { + case DP_DS_PORT_TYPE_DP: + seq_puts(m, "\t\tType: DisplayPort\n"); + break; + case DP_DS_PORT_TYPE_VGA: + seq_puts(m, "\t\tType: VGA\n"); + break; + case DP_DS_PORT_TYPE_DVI: + seq_puts(m, "\t\tType: DVI\n"); + break; + case DP_DS_PORT_TYPE_HDMI: + seq_puts(m, "\t\tType: HDMI\n"); + break; + case DP_DS_PORT_TYPE_NON_EDID: + seq_puts(m, "\t\tType: others without EDID support\n"); + break; + case DP_DS_PORT_TYPE_DP_DUALMODE: + seq_puts(m, "\t\tType: DP++\n"); + break; + case DP_DS_PORT_TYPE_WIRELESS: + seq_puts(m, "\t\tType: Wireless\n"); + break; + default: + seq_puts(m, "\t\tType: N/A\n"); + } + + memset(id, 0, sizeof(id)); + drm_dp_downstream_id(aux, id); + seq_printf(m, "\t\tID: %s\n", id); + + len = drm_dp_dpcd_read(aux, DP_BRANCH_HW_REV, &rev[0], 1); + if (len > 0) + seq_printf(m, "\t\tHW: %d.%d\n", + (rev[0] & 0xf0) >> 4, rev[0] & 0xf); + + len = drm_dp_dpcd_read(aux, DP_BRANCH_SW_REV, rev, 2); + if (len > 0) + seq_printf(m, "\t\tSW: %d.%d\n", rev[0], rev[1]); + + if (detailed_cap_info) { + clk = drm_dp_downstream_max_dotclock(dpcd, port_cap); + if (clk > 0) + seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk); + + clk = drm_dp_downstream_max_tmds_clock(dpcd, port_cap, edid); + if (clk > 0) + seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk); + + clk = drm_dp_downstream_min_tmds_clock(dpcd, port_cap, edid); + if (clk > 0) + seq_printf(m, "\t\tMin TMDS clock: %d kHz\n", clk); + + bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, edid); + + if (bpc > 0) + seq_printf(m, "\t\tMax bpc: %d\n", bpc); + } +} +EXPORT_SYMBOL(drm_dp_downstream_debug); + +/** + * drm_dp_subconnector_type() - get DP branch device type + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + */ +enum drm_mode_subconnector +drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + int type; + if (!drm_dp_is_branch(dpcd)) + return DRM_MODE_SUBCONNECTOR_Native; + /* DP 1.0 approach */ + if (dpcd[DP_DPCD_REV] == DP_DPCD_REV_10) { + type = dpcd[DP_DOWNSTREAMPORT_PRESENT] & + DP_DWN_STRM_PORT_TYPE_MASK; + + switch (type) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + /* Can be HDMI or DVI-D, DVI-D is a safer option */ + return DRM_MODE_SUBCONNECTOR_DVID; + case DP_DWN_STRM_PORT_TYPE_ANALOG: + /* Can be VGA or DVI-A, VGA is more popular */ + return DRM_MODE_SUBCONNECTOR_VGA; + case DP_DWN_STRM_PORT_TYPE_DP: + return DRM_MODE_SUBCONNECTOR_DisplayPort; + case DP_DWN_STRM_PORT_TYPE_OTHER: + default: + return DRM_MODE_SUBCONNECTOR_Unknown; + } + } + type = port_cap[0] & DP_DS_PORT_TYPE_MASK; + + switch (type) { + case DP_DS_PORT_TYPE_DP: + case DP_DS_PORT_TYPE_DP_DUALMODE: + return DRM_MODE_SUBCONNECTOR_DisplayPort; + case DP_DS_PORT_TYPE_VGA: + return DRM_MODE_SUBCONNECTOR_VGA; + case DP_DS_PORT_TYPE_DVI: + return DRM_MODE_SUBCONNECTOR_DVID; + case DP_DS_PORT_TYPE_HDMI: + return DRM_MODE_SUBCONNECTOR_HDMIA; + case DP_DS_PORT_TYPE_WIRELESS: + return DRM_MODE_SUBCONNECTOR_Wireless; + case DP_DS_PORT_TYPE_NON_EDID: + default: + return DRM_MODE_SUBCONNECTOR_Unknown; + } +} +EXPORT_SYMBOL(drm_dp_subconnector_type); + +/** + * drm_mode_set_dp_subconnector_property - set subconnector for DP connector + * @connector: connector to set property on + * @status: connector status + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Called by a driver on every detect event. + */ +void drm_dp_set_subconnector_property(struct drm_connector *connector, + enum drm_connector_status status, + const u8 *dpcd, + const u8 port_cap[4]) +{ + enum drm_mode_subconnector subconnector = DRM_MODE_SUBCONNECTOR_Unknown; + + if (status == connector_status_connected) + subconnector = drm_dp_subconnector_type(dpcd, port_cap); + drm_object_property_set_value(&connector->base, + connector->dev->mode_config.dp_subconnector_property, + subconnector); +} +EXPORT_SYMBOL(drm_dp_set_subconnector_property); + +/** + * drm_dp_read_sink_count_cap() - Check whether a given connector has a valid sink + * count + * @connector: The DRM connector to check + * @dpcd: A cached copy of the connector's DPCD RX capabilities + * @desc: A cached copy of the connector's DP descriptor + * + * See also: drm_dp_read_sink_count() + * + * Returns: %True if the (e)DP connector has a valid sink count that should + * be probed, %false otherwise. + */ +bool drm_dp_read_sink_count_cap(struct drm_connector *connector, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const struct drm_dp_desc *desc) +{ + /* Some eDP panels don't set a valid value for the sink count */ + return connector->connector_type != DRM_MODE_CONNECTOR_eDP && + dpcd[DP_DPCD_REV] >= DP_DPCD_REV_11 && + dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT && + !drm_dp_has_quirk(desc, 0, DP_DPCD_QUIRK_NO_SINK_COUNT); +} +EXPORT_SYMBOL(drm_dp_read_sink_count_cap); + +/** + * drm_dp_read_sink_count() - Retrieve the sink count for a given sink + * @aux: The DP AUX channel to use + * + * See also: drm_dp_read_sink_count_cap() + * + * Returns: The current sink count reported by @aux, or a negative error code + * otherwise. + */ +int drm_dp_read_sink_count(struct drm_dp_aux *aux) +{ + u8 count; + int ret; + + ret = drm_dp_dpcd_readb(aux, DP_SINK_COUNT, &count); + if (ret < 0) + return ret; + if (ret != 1) + return -EIO; + + return DP_GET_SINK_COUNT(count); +} +EXPORT_SYMBOL(drm_dp_read_sink_count); + +/* + * I2C-over-AUX implementation + */ + +static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | + I2C_FUNC_SMBUS_READ_BLOCK_DATA | + I2C_FUNC_SMBUS_BLOCK_PROC_CALL | + I2C_FUNC_10BIT_ADDR; +} + +static void drm_dp_i2c_msg_write_status_update(struct drm_dp_aux_msg *msg) +{ + /* + * In case of i2c defer or short i2c ack reply to a write, + * we need to switch to WRITE_STATUS_UPDATE to drain the + * rest of the message + */ + if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_I2C_WRITE) { + msg->request &= DP_AUX_I2C_MOT; + msg->request |= DP_AUX_I2C_WRITE_STATUS_UPDATE; + } +} + +#define AUX_PRECHARGE_LEN 10 /* 10 to 16 */ +#define AUX_SYNC_LEN (16 + 4) /* preamble + AUX_SYNC_END */ +#define AUX_STOP_LEN 4 +#define AUX_CMD_LEN 4 +#define AUX_ADDRESS_LEN 20 +#define AUX_REPLY_PAD_LEN 4 +#define AUX_LENGTH_LEN 8 + +/* + * Calculate the duration of the AUX request/reply in usec. Gives the + * "best" case estimate, ie. successful while as short as possible. + */ +static int drm_dp_aux_req_duration(const struct drm_dp_aux_msg *msg) +{ + int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN + + AUX_CMD_LEN + AUX_ADDRESS_LEN + AUX_LENGTH_LEN; + + if ((msg->request & DP_AUX_I2C_READ) == 0) + len += msg->size * 8; + + return len; +} + +static int drm_dp_aux_reply_duration(const struct drm_dp_aux_msg *msg) +{ + int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN + + AUX_CMD_LEN + AUX_REPLY_PAD_LEN; + + /* + * For read we expect what was asked. For writes there will + * be 0 or 1 data bytes. Assume 0 for the "best" case. + */ + if (msg->request & DP_AUX_I2C_READ) + len += msg->size * 8; + + return len; +} + +#define I2C_START_LEN 1 +#define I2C_STOP_LEN 1 +#define I2C_ADDR_LEN 9 /* ADDRESS + R/W + ACK/NACK */ +#define I2C_DATA_LEN 9 /* DATA + ACK/NACK */ + +/* + * Calculate the length of the i2c transfer in usec, assuming + * the i2c bus speed is as specified. Gives the the "worst" + * case estimate, ie. successful while as long as possible. + * Doesn't account the the "MOT" bit, and instead assumes each + * message includes a START, ADDRESS and STOP. Neither does it + * account for additional random variables such as clock stretching. + */ +static int drm_dp_i2c_msg_duration(const struct drm_dp_aux_msg *msg, + int i2c_speed_khz) +{ + /* AUX bitrate is 1MHz, i2c bitrate as specified */ + return DIV_ROUND_UP((I2C_START_LEN + I2C_ADDR_LEN + + msg->size * I2C_DATA_LEN + + I2C_STOP_LEN) * 1000, i2c_speed_khz); +} + +/* + * Deterine how many retries should be attempted to successfully transfer + * the specified message, based on the estimated durations of the + * i2c and AUX transfers. + */ +static int drm_dp_i2c_retry_count(const struct drm_dp_aux_msg *msg, + int i2c_speed_khz) +{ + int aux_time_us = drm_dp_aux_req_duration(msg) + + drm_dp_aux_reply_duration(msg); + int i2c_time_us = drm_dp_i2c_msg_duration(msg, i2c_speed_khz); + + return DIV_ROUND_UP(i2c_time_us, aux_time_us + AUX_RETRY_INTERVAL); +} + +/* + * FIXME currently assumes 10 kHz as some real world devices seem + * to require it. We should query/set the speed via DPCD if supported. + */ +static int dp_aux_i2c_speed_khz __read_mostly = 10; +module_param_unsafe(dp_aux_i2c_speed_khz, int, 0644); +MODULE_PARM_DESC(dp_aux_i2c_speed_khz, + "Assumed speed of the i2c bus in kHz, (1-400, default 10)"); + +/* + * Transfer a single I2C-over-AUX message and handle various error conditions, + * retrying the transaction as appropriate. It is assumed that the + * &drm_dp_aux.transfer function does not modify anything in the msg other than the + * reply field. + * + * Returns bytes transferred on success, or a negative error code on failure. + */ +static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{ + unsigned int retry, defer_i2c; + int ret; + /* + * DP1.2 sections 2.7.7.1.5.6.1 and 2.7.7.1.6.6.1: A DP Source device + * is required to retry at least seven times upon receiving AUX_DEFER + * before giving up the AUX transaction. + * + * We also try to account for the i2c bus speed. + */ + int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz)); + + for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) { + ret = aux->transfer(aux, msg); + if (ret < 0) { + if (ret == -EBUSY) + continue; + + /* + * While timeouts can be errors, they're usually normal + * behavior (for instance, when a driver tries to + * communicate with a non-existant DisplayPort device). + * Avoid spamming the kernel log with timeout errors. + */ + if (ret == -ETIMEDOUT) + DRM_DEBUG_KMS_RATELIMITED("%s: transaction timed out\n", + aux->name); + else + DRM_DEBUG_KMS("%s: transaction failed: %d\n", + aux->name, ret); + return ret; + } + + + switch (msg->reply & DP_AUX_NATIVE_REPLY_MASK) { + case DP_AUX_NATIVE_REPLY_ACK: + /* + * For I2C-over-AUX transactions this isn't enough, we + * need to check for the I2C ACK reply. + */ + break; + + case DP_AUX_NATIVE_REPLY_NACK: + DRM_DEBUG_KMS("%s: native nack (result=%d, size=%zu)\n", + aux->name, ret, msg->size); + return -EREMOTEIO; + + case DP_AUX_NATIVE_REPLY_DEFER: + DRM_DEBUG_KMS("%s: native defer\n", aux->name); + /* + * We could check for I2C bit rate capabilities and if + * available adjust this interval. We could also be + * more careful with DP-to-legacy adapters where a + * long legacy cable may force very low I2C bit rates. + * + * For now just defer for long enough to hopefully be + * safe for all use-cases. + */ + usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); + continue; + + default: + DRM_ERROR("%s: invalid native reply %#04x\n", + aux->name, msg->reply); + return -EREMOTEIO; + } + + switch (msg->reply & DP_AUX_I2C_REPLY_MASK) { + case DP_AUX_I2C_REPLY_ACK: + /* + * Both native ACK and I2C ACK replies received. We + * can assume the transfer was successful. + */ + if (ret != msg->size) + drm_dp_i2c_msg_write_status_update(msg); + return ret; + + case DP_AUX_I2C_REPLY_NACK: + DRM_DEBUG_KMS("%s: I2C nack (result=%d, size=%zu)\n", + aux->name, ret, msg->size); + aux->i2c_nack_count++; + return -EREMOTEIO; + + case DP_AUX_I2C_REPLY_DEFER: + DRM_DEBUG_KMS("%s: I2C defer\n", aux->name); + /* DP Compliance Test 4.2.2.5 Requirement: + * Must have at least 7 retries for I2C defers on the + * transaction to pass this test + */ + aux->i2c_defer_count++; + if (defer_i2c < 7) + defer_i2c++; + usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); + drm_dp_i2c_msg_write_status_update(msg); + + continue; + + default: + DRM_ERROR("%s: invalid I2C reply %#04x\n", + aux->name, msg->reply); + return -EREMOTEIO; + } + } + + DRM_DEBUG_KMS("%s: Too many retries, giving up\n", aux->name); + return -EREMOTEIO; +} + +static void drm_dp_i2c_msg_set_request(struct drm_dp_aux_msg *msg, + const struct i2c_msg *i2c_msg) +{ + msg->request = (i2c_msg->flags & I2C_M_RD) ? + DP_AUX_I2C_READ : DP_AUX_I2C_WRITE; + if (!(i2c_msg->flags & I2C_M_STOP)) + msg->request |= DP_AUX_I2C_MOT; +} + +/* + * Keep retrying drm_dp_i2c_do_msg until all data has been transferred. + * + * Returns an error code on failure, or a recommended transfer size on success. + */ +static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *orig_msg) +{ + int err, ret = orig_msg->size; + struct drm_dp_aux_msg msg = *orig_msg; + + while (msg.size > 0) { + err = drm_dp_i2c_do_msg(aux, &msg); + if (err <= 0) + return err == 0 ? -EPROTO : err; + + if (err < msg.size && err < ret) { + DRM_DEBUG_KMS("%s: Partial I2C reply: requested %zu bytes got %d bytes\n", + aux->name, msg.size, err); + ret = err; + } + + msg.size -= err; + msg.buffer += err; + } + + return ret; +} + +/* + * Bizlink designed DP->DVI-D Dual Link adapters require the I2C over AUX + * packets to be as large as possible. If not, the I2C transactions never + * succeed. Hence the default is maximum. + */ +static int dp_aux_i2c_transfer_size __read_mostly = DP_AUX_MAX_PAYLOAD_BYTES; +module_param_unsafe(dp_aux_i2c_transfer_size, int, 0644); +MODULE_PARM_DESC(dp_aux_i2c_transfer_size, + "Number of bytes to transfer in a single I2C over DP AUX CH message, (1-16, default 16)"); + +static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, + int num) +{ + struct drm_dp_aux *aux = adapter->algo_data; + unsigned int i, j; + unsigned transfer_size; + struct drm_dp_aux_msg msg; + int err = 0; + + dp_aux_i2c_transfer_size = clamp(dp_aux_i2c_transfer_size, 1, DP_AUX_MAX_PAYLOAD_BYTES); + + memset(&msg, 0, sizeof(msg)); + + for (i = 0; i < num; i++) { + msg.address = msgs[i].addr; + drm_dp_i2c_msg_set_request(&msg, &msgs[i]); + /* Send a bare address packet to start the transaction. + * Zero sized messages specify an address only (bare + * address) transaction. + */ + msg.buffer = NULL; + msg.size = 0; + err = drm_dp_i2c_do_msg(aux, &msg); + + /* + * Reset msg.request in case in case it got + * changed into a WRITE_STATUS_UPDATE. + */ + drm_dp_i2c_msg_set_request(&msg, &msgs[i]); + + if (err < 0) + break; + /* We want each transaction to be as large as possible, but + * we'll go to smaller sizes if the hardware gives us a + * short reply. + */ + transfer_size = dp_aux_i2c_transfer_size; + for (j = 0; j < msgs[i].len; j += msg.size) { + msg.buffer = msgs[i].buf + j; + msg.size = min(transfer_size, msgs[i].len - j); + + err = drm_dp_i2c_drain_msg(aux, &msg); + + /* + * Reset msg.request in case in case it got + * changed into a WRITE_STATUS_UPDATE. + */ + drm_dp_i2c_msg_set_request(&msg, &msgs[i]); + + if (err < 0) + break; + transfer_size = err; + } + if (err < 0) + break; + } + if (err >= 0) + err = num; + /* Send a bare address packet to close out the transaction. + * Zero sized messages specify an address only (bare + * address) transaction. + */ + msg.request &= ~DP_AUX_I2C_MOT; + msg.buffer = NULL; + msg.size = 0; + (void)drm_dp_i2c_do_msg(aux, &msg); + + return err; +} + +static const struct i2c_algorithm drm_dp_i2c_algo = { + .functionality = drm_dp_i2c_functionality, + .master_xfer = drm_dp_i2c_xfer, +}; + +static struct drm_dp_aux *i2c_to_aux(struct i2c_adapter *i2c) +{ + return container_of(i2c, struct drm_dp_aux, ddc); +} + +static void lock_bus(struct i2c_adapter *i2c, unsigned int flags) +{ + mutex_lock(&i2c_to_aux(i2c)->hw_mutex); +} + +static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags) +{ + return mutex_trylock(&i2c_to_aux(i2c)->hw_mutex); +} + +static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags) +{ + mutex_unlock(&i2c_to_aux(i2c)->hw_mutex); +} + +static const struct i2c_lock_operations drm_dp_i2c_lock_ops = { + .lock_bus = lock_bus, + .trylock_bus = trylock_bus, + .unlock_bus = unlock_bus, +}; + +static int drm_dp_aux_get_crc(struct drm_dp_aux *aux, u8 *crc) +{ + u8 buf, count; + int ret; + + ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf); + if (ret < 0) + return ret; + + WARN_ON(!(buf & DP_TEST_SINK_START)); + + ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK_MISC, &buf); + if (ret < 0) + return ret; + + count = buf & DP_TEST_COUNT_MASK; + if (count == aux->crc_count) + return -EAGAIN; /* No CRC yet */ + + aux->crc_count = count; + + /* + * At DP_TEST_CRC_R_CR, there's 6 bytes containing CRC data, 2 bytes + * per component (RGB or CrYCb). + */ + ret = drm_dp_dpcd_read(aux, DP_TEST_CRC_R_CR, crc, 6); + if (ret < 0) + return ret; + + return 0; +} + +static void drm_dp_aux_crc_work(struct work_struct *work) +{ + struct drm_dp_aux *aux = container_of(work, struct drm_dp_aux, + crc_work); + struct drm_crtc *crtc; + u8 crc_bytes[6]; + uint32_t crcs[3]; + int ret; + + if (WARN_ON(!aux->crtc)) + return; + + crtc = aux->crtc; + while (crtc->crc.opened) { + drm_crtc_wait_one_vblank(crtc); + if (!crtc->crc.opened) + break; + + ret = drm_dp_aux_get_crc(aux, crc_bytes); + if (ret == -EAGAIN) { + usleep_range(1000, 2000); + ret = drm_dp_aux_get_crc(aux, crc_bytes); + } + + if (ret == -EAGAIN) { + DRM_DEBUG_KMS("%s: Get CRC failed after retrying: %d\n", + aux->name, ret); + continue; + } else if (ret) { + DRM_DEBUG_KMS("%s: Failed to get a CRC: %d\n", + aux->name, ret); + continue; + } + + crcs[0] = crc_bytes[0] | crc_bytes[1] << 8; + crcs[1] = crc_bytes[2] | crc_bytes[3] << 8; + crcs[2] = crc_bytes[4] | crc_bytes[5] << 8; + drm_crtc_add_crc_entry(crtc, false, 0, crcs); + } +} + +/** + * drm_dp_remote_aux_init() - minimally initialise a remote aux channel + * @aux: DisplayPort AUX channel + * + * Used for remote aux channel in general. Merely initialize the crc work + * struct. + */ +void drm_dp_remote_aux_init(struct drm_dp_aux *aux) +{ + INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work); +} +EXPORT_SYMBOL(drm_dp_remote_aux_init); + +/** + * drm_dp_aux_init() - minimally initialise an aux channel + * @aux: DisplayPort AUX channel + * + * If you need to use the drm_dp_aux's i2c adapter prior to registering it + * with the outside world, call drm_dp_aux_init() first. You must still + * call drm_dp_aux_register() once the connector has been registered to + * allow userspace access to the auxiliary DP channel. + */ +void drm_dp_aux_init(struct drm_dp_aux *aux) +{ + mutex_init(&aux->hw_mutex); + mutex_init(&aux->cec.lock); + INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work); + + aux->ddc.algo = &drm_dp_i2c_algo; + aux->ddc.algo_data = aux; + aux->ddc.retries = 3; + + aux->ddc.lock_ops = &drm_dp_i2c_lock_ops; +} +EXPORT_SYMBOL(drm_dp_aux_init); + +/** + * drm_dp_aux_register() - initialise and register aux channel + * @aux: DisplayPort AUX channel + * + * Automatically calls drm_dp_aux_init() if this hasn't been done yet. + * This should only be called when the underlying &struct drm_connector is + * initialiazed already. Therefore the best place to call this is from + * &drm_connector_funcs.late_register. Not that drivers which don't follow this + * will Oops when CONFIG_DRM_DP_AUX_CHARDEV is enabled. + * + * Drivers which need to use the aux channel before that point (e.g. at driver + * load time, before drm_dev_register() has been called) need to call + * drm_dp_aux_init(). + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_aux_register(struct drm_dp_aux *aux) +{ + int ret; + + if (!aux->ddc.algo) + drm_dp_aux_init(aux); + + aux->ddc.class = I2C_CLASS_DDC; + aux->ddc.owner = THIS_MODULE; + aux->ddc.dev.parent = aux->dev; + + strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev), + sizeof(aux->ddc.name)); + + ret = drm_dp_aux_register_devnode(aux); + if (ret) + return ret; + + ret = i2c_add_adapter(&aux->ddc); + if (ret) { + drm_dp_aux_unregister_devnode(aux); + return ret; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_aux_register); + +/** + * drm_dp_aux_unregister() - unregister an AUX adapter + * @aux: DisplayPort AUX channel + */ +void drm_dp_aux_unregister(struct drm_dp_aux *aux) +{ + drm_dp_aux_unregister_devnode(aux); + i2c_del_adapter(&aux->ddc); +} +EXPORT_SYMBOL(drm_dp_aux_unregister); + +#define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x) + +/** + * drm_dp_psr_setup_time() - PSR setup in time usec + * @psr_cap: PSR capabilities from DPCD + * + * Returns: + * PSR setup time for the panel in microseconds, negative + * error code on failure. + */ +int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]) +{ + static const u16 psr_setup_time_us[] = { + PSR_SETUP_TIME(330), + PSR_SETUP_TIME(275), + PSR_SETUP_TIME(220), + PSR_SETUP_TIME(165), + PSR_SETUP_TIME(110), + PSR_SETUP_TIME(55), + PSR_SETUP_TIME(0), + }; + int i; + + i = (psr_cap[1] & DP_PSR_SETUP_TIME_MASK) >> DP_PSR_SETUP_TIME_SHIFT; + if (i >= ARRAY_SIZE(psr_setup_time_us)) + return -EINVAL; + + return psr_setup_time_us[i]; +} +EXPORT_SYMBOL(drm_dp_psr_setup_time); + +#undef PSR_SETUP_TIME + +/** + * drm_dp_start_crc() - start capture of frame CRCs + * @aux: DisplayPort AUX channel + * @crtc: CRTC displaying the frames whose CRCs are to be captured + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc) +{ + u8 buf; + int ret; + + ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf); + if (ret < 0) + return ret; + + ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf | DP_TEST_SINK_START); + if (ret < 0) + return ret; + + aux->crc_count = 0; + aux->crtc = crtc; + schedule_work(&aux->crc_work); + + return 0; +} +EXPORT_SYMBOL(drm_dp_start_crc); + +/** + * drm_dp_stop_crc() - stop capture of frame CRCs + * @aux: DisplayPort AUX channel + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_stop_crc(struct drm_dp_aux *aux) +{ + u8 buf; + int ret; + + ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf); + if (ret < 0) + return ret; + + ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf & ~DP_TEST_SINK_START); + if (ret < 0) + return ret; + + flush_work(&aux->crc_work); + aux->crtc = NULL; + + return 0; +} +EXPORT_SYMBOL(drm_dp_stop_crc); + +struct dpcd_quirk { + u8 oui[3]; + u8 device_id[6]; + bool is_branch; + u32 quirks; +}; + +#define OUI(first, second, third) { (first), (second), (third) } +#define DEVICE_ID(first, second, third, fourth, fifth, sixth) \ + { (first), (second), (third), (fourth), (fifth), (sixth) } + +#define DEVICE_ID_ANY DEVICE_ID(0, 0, 0, 0, 0, 0) + +static const struct dpcd_quirk dpcd_quirk_list[] = { + /* Analogix 7737 needs reduced M and N at HBR2 link rates */ + { OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_CONSTANT_N) }, + /* LG LP140WF6-SPM1 eDP panel */ + { OUI(0x00, 0x22, 0xb9), DEVICE_ID('s', 'i', 'v', 'a', 'r', 'T'), false, BIT(DP_DPCD_QUIRK_CONSTANT_N) }, + /* Apple panels need some additional handling to support PSR */ + { OUI(0x00, 0x10, 0xfa), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_NO_PSR) }, + /* CH7511 seems to leave SINK_COUNT zeroed */ + { OUI(0x00, 0x00, 0x00), DEVICE_ID('C', 'H', '7', '5', '1', '1'), false, BIT(DP_DPCD_QUIRK_NO_SINK_COUNT) }, + /* Synaptics DP1.4 MST hubs can support DSC without virtual DPCD */ + { OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) }, + /* Apple MacBookPro 2017 15 inch eDP Retina panel reports too low DP_MAX_LINK_RATE */ + { OUI(0x00, 0x10, 0xfa), DEVICE_ID(101, 68, 21, 101, 98, 97), false, BIT(DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS) }, +}; + +#undef OUI + +/* + * Get a bit mask of DPCD quirks for the sink/branch device identified by + * ident. The quirk data is shared but it's up to the drivers to act on the + * data. + * + * For now, only the OUI (first three bytes) is used, but this may be extended + * to device identification string and hardware/firmware revisions later. + */ +static u32 +drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) +{ + const struct dpcd_quirk *quirk; + u32 quirks = 0; + int i; + u8 any_device[] = DEVICE_ID_ANY; + + for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) { + quirk = &dpcd_quirk_list[i]; + + if (quirk->is_branch != is_branch) + continue; + + if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0) + continue; + + if (memcmp(quirk->device_id, any_device, sizeof(any_device)) != 0 && + memcmp(quirk->device_id, ident->device_id, sizeof(ident->device_id)) != 0) + continue; + + quirks |= quirk->quirks; + } + + return quirks; +} + +#undef DEVICE_ID_ANY +#undef DEVICE_ID + +struct edid_quirk { + u8 mfg_id[2]; + u8 prod_id[2]; + u32 quirks; +}; + +#define MFG(first, second) { (first), (second) } +#define PROD_ID(first, second) { (first), (second) } + +/* + * Some devices have unreliable OUIDs where they don't set the device ID + * correctly, and as a result we need to use the EDID for finding additional + * DP quirks in such cases. + */ +static const struct edid_quirk edid_quirk_list[] = { + /* Optional 4K AMOLED panel in the ThinkPad X1 Extreme 2nd Generation + * only supports DPCD backlight controls + */ + { MFG(0x4c, 0x83), PROD_ID(0x41, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) }, + /* + * Some Dell CML 2020 systems have panels support both AUX and PWM + * backlight control, and some only support AUX backlight control. All + * said panels start up in AUX mode by default, and we don't have any + * support for disabling HDR mode on these panels which would be + * required to switch to PWM backlight control mode (plus, I'm not + * even sure we want PWM backlight controls over DPCD backlight + * controls anyway...). Until we have a better way of detecting these, + * force DPCD backlight mode on all of them. + */ + { MFG(0x06, 0xaf), PROD_ID(0x9b, 0x32), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) }, + { MFG(0x06, 0xaf), PROD_ID(0xeb, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) }, + { MFG(0x4d, 0x10), PROD_ID(0xc7, 0x14), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) }, + { MFG(0x4d, 0x10), PROD_ID(0xe6, 0x14), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) }, + { MFG(0x4c, 0x83), PROD_ID(0x47, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) }, +}; + +#undef MFG +#undef PROD_ID + +/** + * drm_dp_get_edid_quirks() - Check the EDID of a DP device to find additional + * DP-specific quirks + * @edid: The EDID to check + * + * While OUIDs are meant to be used to recognize a DisplayPort device, a lot + * of manufacturers don't seem to like following standards and neglect to fill + * the dev-ID in, making it impossible to only use OUIDs for determining + * quirks in some cases. This function can be used to check the EDID and look + * up any additional DP quirks. The bits returned by this function correspond + * to the quirk bits in &drm_dp_quirk. + * + * Returns: a bitmask of quirks, if any. The driver can check this using + * drm_dp_has_quirk(). + */ +u32 drm_dp_get_edid_quirks(const struct edid *edid) +{ + const struct edid_quirk *quirk; + u32 quirks = 0; + int i; + + if (!edid) + return 0; + + for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) { + quirk = &edid_quirk_list[i]; + if (memcmp(quirk->mfg_id, edid->mfg_id, + sizeof(edid->mfg_id)) == 0 && + memcmp(quirk->prod_id, edid->prod_code, + sizeof(edid->prod_code)) == 0) + quirks |= quirk->quirks; + } + + DRM_DEBUG_KMS("DP sink: EDID mfg %*phD prod-ID %*phD quirks: 0x%04x\n", + (int)sizeof(edid->mfg_id), edid->mfg_id, + (int)sizeof(edid->prod_code), edid->prod_code, quirks); + + return quirks; +} +EXPORT_SYMBOL(drm_dp_get_edid_quirks); + +/** + * drm_dp_read_desc - read sink/branch descriptor from DPCD + * @aux: DisplayPort AUX channel + * @desc: Device descriptor to fill from DPCD + * @is_branch: true for branch devices, false for sink devices + * + * Read DPCD 0x400 (sink) or 0x500 (branch) into @desc. Also debug log the + * identification. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, + bool is_branch) +{ + struct drm_dp_dpcd_ident *ident = &desc->ident; + unsigned int offset = is_branch ? DP_BRANCH_OUI : DP_SINK_OUI; + int ret, dev_id_len; + + ret = drm_dp_dpcd_read(aux, offset, ident, sizeof(*ident)); + if (ret < 0) + return ret; + + desc->quirks = drm_dp_get_quirks(ident, is_branch); + + dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id)); + + DRM_DEBUG_KMS("%s: DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", + aux->name, is_branch ? "branch" : "sink", + (int)sizeof(ident->oui), ident->oui, + dev_id_len, ident->device_id, + ident->hw_rev >> 4, ident->hw_rev & 0xf, + ident->sw_major_rev, ident->sw_minor_rev, + desc->quirks); + + return 0; +} +EXPORT_SYMBOL(drm_dp_read_desc); + +/** + * drm_dp_dsc_sink_max_slice_count() - Get the max slice count + * supported by the DSC sink. + * @dsc_dpcd: DSC capabilities from DPCD + * @is_edp: true if its eDP, false for DP + * + * Read the slice capabilities DPCD register from DSC sink to get + * the maximum slice count supported. This is used to populate + * the DSC parameters in the &struct drm_dsc_config by the driver. + * Driver creates an infoframe using these parameters to populate + * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC + * infoframe using the helper function drm_dsc_pps_infoframe_pack() + * + * Returns: + * Maximum slice count supported by DSC sink or 0 its invalid + */ +u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], + bool is_edp) +{ + u8 slice_cap1 = dsc_dpcd[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT]; + + if (is_edp) { + /* For eDP, register DSC_SLICE_CAPABILITIES_1 gives slice count */ + if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK) + return 4; + if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK) + return 2; + if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK) + return 1; + } else { + /* For DP, use values from DSC_SLICE_CAP_1 and DSC_SLICE_CAP2 */ + u8 slice_cap2 = dsc_dpcd[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT]; + + if (slice_cap2 & DP_DSC_24_PER_DP_DSC_SINK) + return 24; + if (slice_cap2 & DP_DSC_20_PER_DP_DSC_SINK) + return 20; + if (slice_cap2 & DP_DSC_16_PER_DP_DSC_SINK) + return 16; + if (slice_cap1 & DP_DSC_12_PER_DP_DSC_SINK) + return 12; + if (slice_cap1 & DP_DSC_10_PER_DP_DSC_SINK) + return 10; + if (slice_cap1 & DP_DSC_8_PER_DP_DSC_SINK) + return 8; + if (slice_cap1 & DP_DSC_6_PER_DP_DSC_SINK) + return 6; + if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK) + return 4; + if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK) + return 2; + if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK) + return 1; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_dsc_sink_max_slice_count); + +/** + * drm_dp_dsc_sink_line_buf_depth() - Get the line buffer depth in bits + * @dsc_dpcd: DSC capabilities from DPCD + * + * Read the DSC DPCD register to parse the line buffer depth in bits which is + * number of bits of precision within the decoder line buffer supported by + * the DSC sink. This is used to populate the DSC parameters in the + * &struct drm_dsc_config by the driver. + * Driver creates an infoframe using these parameters to populate + * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC + * infoframe using the helper function drm_dsc_pps_infoframe_pack() + * + * Returns: + * Line buffer depth supported by DSC panel or 0 its invalid + */ +u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) +{ + u8 line_buf_depth = dsc_dpcd[DP_DSC_LINE_BUF_BIT_DEPTH - DP_DSC_SUPPORT]; + + switch (line_buf_depth & DP_DSC_LINE_BUF_BIT_DEPTH_MASK) { + case DP_DSC_LINE_BUF_BIT_DEPTH_9: + return 9; + case DP_DSC_LINE_BUF_BIT_DEPTH_10: + return 10; + case DP_DSC_LINE_BUF_BIT_DEPTH_11: + return 11; + case DP_DSC_LINE_BUF_BIT_DEPTH_12: + return 12; + case DP_DSC_LINE_BUF_BIT_DEPTH_13: + return 13; + case DP_DSC_LINE_BUF_BIT_DEPTH_14: + return 14; + case DP_DSC_LINE_BUF_BIT_DEPTH_15: + return 15; + case DP_DSC_LINE_BUF_BIT_DEPTH_16: + return 16; + case DP_DSC_LINE_BUF_BIT_DEPTH_8: + return 8; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_dsc_sink_line_buf_depth); + +/** + * drm_dp_dsc_sink_supported_input_bpcs() - Get all the input bits per component + * values supported by the DSC sink. + * @dsc_dpcd: DSC capabilities from DPCD + * @dsc_bpc: An array to be filled by this helper with supported + * input bpcs. + * + * Read the DSC DPCD from the sink device to parse the supported bits per + * component values. This is used to populate the DSC parameters + * in the &struct drm_dsc_config by the driver. + * Driver creates an infoframe using these parameters to populate + * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC + * infoframe using the helper function drm_dsc_pps_infoframe_pack() + * + * Returns: + * Number of input BPC values parsed from the DPCD + */ +int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], + u8 dsc_bpc[3]) +{ + int num_bpc = 0; + u8 color_depth = dsc_dpcd[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT]; + + if (color_depth & DP_DSC_12_BPC) + dsc_bpc[num_bpc++] = 12; + if (color_depth & DP_DSC_10_BPC) + dsc_bpc[num_bpc++] = 10; + if (color_depth & DP_DSC_8_BPC) + dsc_bpc[num_bpc++] = 8; + + return num_bpc; +} +EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs); + +/** + * drm_dp_get_phy_test_pattern() - get the requested pattern from the sink. + * @aux: DisplayPort AUX channel + * @data: DP phy compliance test parameters. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux, + struct drm_dp_phy_test_params *data) +{ + int err; + u8 rate, lanes; + + err = drm_dp_dpcd_readb(aux, DP_TEST_LINK_RATE, &rate); + if (err < 0) + return err; + data->link_rate = drm_dp_bw_code_to_link_rate(rate); + + err = drm_dp_dpcd_readb(aux, DP_TEST_LANE_COUNT, &lanes); + if (err < 0) + return err; + data->num_lanes = lanes & DP_MAX_LANE_COUNT_MASK; + + if (lanes & DP_ENHANCED_FRAME_CAP) + data->enhanced_frame_cap = true; + + err = drm_dp_dpcd_readb(aux, DP_PHY_TEST_PATTERN, &data->phy_pattern); + if (err < 0) + return err; + + switch (data->phy_pattern) { + case DP_PHY_TEST_PATTERN_80BIT_CUSTOM: + err = drm_dp_dpcd_read(aux, DP_TEST_80BIT_CUSTOM_PATTERN_7_0, + &data->custom80, sizeof(data->custom80)); + if (err < 0) + return err; + + break; + case DP_PHY_TEST_PATTERN_CP2520: + err = drm_dp_dpcd_read(aux, DP_TEST_HBR2_SCRAMBLER_RESET, + &data->hbr2_reset, + sizeof(data->hbr2_reset)); + if (err < 0) + return err; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_get_phy_test_pattern); + +/** + * drm_dp_set_phy_test_pattern() - set the pattern to the sink. + * @aux: DisplayPort AUX channel + * @data: DP phy compliance test parameters. + * @dp_rev: DP revision to use for compliance testing + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux, + struct drm_dp_phy_test_params *data, u8 dp_rev) +{ + int err, i; + u8 test_pattern; + + test_pattern = data->phy_pattern; + if (dp_rev < 0x12) { + test_pattern = (test_pattern << 2) & + DP_LINK_QUAL_PATTERN_11_MASK; + err = drm_dp_dpcd_writeb(aux, DP_TRAINING_PATTERN_SET, + test_pattern); + if (err < 0) + return err; + } else { + for (i = 0; i < data->num_lanes; i++) { + err = drm_dp_dpcd_writeb(aux, + DP_LINK_QUAL_LANE0_SET + i, + test_pattern); + if (err < 0) + return err; + } + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_set_phy_test_pattern); + +static const char *dp_pixelformat_get_name(enum dp_pixelformat pixelformat) +{ + if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED) + return "Invalid"; + + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "RGB"; + case DP_PIXELFORMAT_YUV444: + return "YUV444"; + case DP_PIXELFORMAT_YUV422: + return "YUV422"; + case DP_PIXELFORMAT_YUV420: + return "YUV420"; + case DP_PIXELFORMAT_Y_ONLY: + return "Y_ONLY"; + case DP_PIXELFORMAT_RAW: + return "RAW"; + default: + return "Reserved"; + } +} + +static const char *dp_colorimetry_get_name(enum dp_pixelformat pixelformat, + enum dp_colorimetry colorimetry) +{ + if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED) + return "Invalid"; + + switch (colorimetry) { + case DP_COLORIMETRY_DEFAULT: + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "sRGB"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "BT.601"; + case DP_PIXELFORMAT_Y_ONLY: + return "DICOM PS3.14"; + case DP_PIXELFORMAT_RAW: + return "Custom Color Profile"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_RGB_WIDE_FIXED: /* and DP_COLORIMETRY_BT709_YCC */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "Wide Fixed"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "BT.709"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_RGB_WIDE_FLOAT: /* and DP_COLORIMETRY_XVYCC_601 */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "Wide Float"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "xvYCC 601"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_OPRGB: /* and DP_COLORIMETRY_XVYCC_709 */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "OpRGB"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "xvYCC 709"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_DCI_P3_RGB: /* and DP_COLORIMETRY_SYCC_601 */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "DCI-P3"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "sYCC 601"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_RGB_CUSTOM: /* and DP_COLORIMETRY_OPYCC_601 */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "Custom Profile"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "OpYCC 601"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_BT2020_RGB: /* and DP_COLORIMETRY_BT2020_CYCC */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "BT.2020 RGB"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "BT.2020 CYCC"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_BT2020_YCC: + switch (pixelformat) { + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "BT.2020 YCC"; + default: + return "Reserved"; + } + default: + return "Invalid"; + } +} + +static const char *dp_dynamic_range_get_name(enum dp_dynamic_range dynamic_range) +{ + switch (dynamic_range) { + case DP_DYNAMIC_RANGE_VESA: + return "VESA range"; + case DP_DYNAMIC_RANGE_CTA: + return "CTA range"; + default: + return "Invalid"; + } +} + +static const char *dp_content_type_get_name(enum dp_content_type content_type) +{ + switch (content_type) { + case DP_CONTENT_TYPE_NOT_DEFINED: + return "Not defined"; + case DP_CONTENT_TYPE_GRAPHICS: + return "Graphics"; + case DP_CONTENT_TYPE_PHOTO: + return "Photo"; + case DP_CONTENT_TYPE_VIDEO: + return "Video"; + case DP_CONTENT_TYPE_GAME: + return "Game"; + default: + return "Reserved"; + } +} + +void drm_dp_vsc_sdp_log(const char *level, struct device *dev, + const struct drm_dp_vsc_sdp *vsc) +{ +#define DP_SDP_LOG(fmt, ...) dev_printk(level, dev, fmt, ##__VA_ARGS__) + DP_SDP_LOG("DP SDP: %s, revision %u, length %u\n", "VSC", + vsc->revision, vsc->length); + DP_SDP_LOG(" pixelformat: %s\n", + dp_pixelformat_get_name(vsc->pixelformat)); + DP_SDP_LOG(" colorimetry: %s\n", + dp_colorimetry_get_name(vsc->pixelformat, vsc->colorimetry)); + DP_SDP_LOG(" bpc: %u\n", vsc->bpc); + DP_SDP_LOG(" dynamic range: %s\n", + dp_dynamic_range_get_name(vsc->dynamic_range)); + DP_SDP_LOG(" content type: %s\n", + dp_content_type_get_name(vsc->content_type)); +#undef DP_SDP_LOG +} +EXPORT_SYMBOL(drm_dp_vsc_sdp_log); |