diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 1501 |
1 files changed, 0 insertions, 1501 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c deleted file mode 100644 index 0b994d083a89..000000000000 --- a/drivers/gpu/drm/drm_dp_helper.c +++ /dev/null @@ -1,1501 +0,0 @@ -/* - * 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_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); - -void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { - int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & - DP_TRAINING_AUX_RD_MASK; - - if (rd_interval > 4) - DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n", - rd_interval); - - if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) - udelay(100); - else - mdelay(rd_interval * 4); -} -EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay); - -void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { - int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & - DP_TRAINING_AUX_RD_MASK; - - if (rd_interval > 4) - DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n", - rd_interval); - - if (rd_interval == 0) - udelay(400); - else - mdelay(rd_interval * 4); -} -EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay); - -u8 drm_dp_link_rate_to_bw_code(int link_rate) -{ - switch (link_rate) { - default: - WARN(1, "unknown DP link rate %d, using %x\n", link_rate, - DP_LINK_BW_1_62); - /* fall through */ - case 162000: - return DP_LINK_BW_1_62; - case 270000: - return DP_LINK_BW_2_7; - case 540000: - return DP_LINK_BW_5_4; - case 810000: - return DP_LINK_BW_8_1; - } -} -EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code); - -int drm_dp_bw_code_to_link_rate(u8 link_bw) -{ - switch (link_bw) { - default: - WARN(1, "unknown DP link BW code %x, using 162000\n", link_bw); - /* fall through */ - case DP_LINK_BW_1_62: - return 162000; - case DP_LINK_BW_2_7: - return 270000; - case DP_LINK_BW_5_4: - return 540000; - case DP_LINK_BW_8_1: - return 810000; - } -} -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("Too many retries, giving up. First error: %d\n", 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 - * @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. - */ - ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer, - 1); - if (ret != 1) - goto out; - - 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 - * @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; - - 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); - -/** - * drm_dp_link_probe() - probe a DisplayPort link for capabilities - * @aux: DisplayPort AUX channel - * @link: pointer to structure in which to return link capabilities - * - * The structure filled in by this function can usually be passed directly - * into drm_dp_link_power_up() and drm_dp_link_configure() to power up and - * configure the link based on the link's capabilities. - * - * Returns 0 on success or a negative error code on failure. - */ -int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link) -{ - u8 values[3]; - int err; - - memset(link, 0, sizeof(*link)); - - err = drm_dp_dpcd_read(aux, DP_DPCD_REV, values, sizeof(values)); - if (err < 0) - return err; - - link->revision = values[0]; - link->rate = drm_dp_bw_code_to_link_rate(values[1]); - link->num_lanes = values[2] & DP_MAX_LANE_COUNT_MASK; - - if (values[2] & DP_ENHANCED_FRAME_CAP) - link->capabilities |= DP_LINK_CAP_ENHANCED_FRAMING; - - return 0; -} -EXPORT_SYMBOL(drm_dp_link_probe); - -/** - * drm_dp_link_power_up() - power up a DisplayPort link - * @aux: DisplayPort AUX channel - * @link: pointer to a structure containing the link configuration - * - * Returns 0 on success or a negative error code on failure. - */ -int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link) -{ - u8 value; - int err; - - /* DP_SET_POWER register is only available on DPCD v1.1 and later */ - if (link->revision < 0x11) - return 0; - - err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); - if (err < 0) - return err; - - value &= ~DP_SET_POWER_MASK; - value |= DP_SET_POWER_D0; - - err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); - if (err < 0) - return err; - - /* - * According to the DP 1.1 specification, a "Sink Device must exit the - * power saving state within 1 ms" (Section 2.5.3.1, Table 5-52, "Sink - * Control Field" (register 0x600). - */ - usleep_range(1000, 2000); - - return 0; -} -EXPORT_SYMBOL(drm_dp_link_power_up); - -/** - * drm_dp_link_power_down() - power down a DisplayPort link - * @aux: DisplayPort AUX channel - * @link: pointer to a structure containing the link configuration - * - * Returns 0 on success or a negative error code on failure. - */ -int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link) -{ - u8 value; - int err; - - /* DP_SET_POWER register is only available on DPCD v1.1 and later */ - if (link->revision < 0x11) - return 0; - - err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); - if (err < 0) - return err; - - value &= ~DP_SET_POWER_MASK; - value |= DP_SET_POWER_D3; - - err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); - if (err < 0) - return err; - - return 0; -} -EXPORT_SYMBOL(drm_dp_link_power_down); - -/** - * drm_dp_link_configure() - configure a DisplayPort link - * @aux: DisplayPort AUX channel - * @link: pointer to a structure containing the link configuration - * - * Returns 0 on success or a negative error code on failure. - */ -int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link) -{ - u8 values[2]; - int err; - - values[0] = drm_dp_link_rate_to_bw_code(link->rate); - values[1] = link->num_lanes; - - if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING) - values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN; - - err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, values, sizeof(values)); - if (err < 0) - return err; - - return 0; -} -EXPORT_SYMBOL(drm_dp_link_configure); - -/** - * drm_dp_downstream_max_clock() - extract branch device max - * pixel rate for legacy VGA - * converter or max TMDS clock - * rate for others - * @dpcd: DisplayPort configuration data - * @port_cap: port capabilities - * - * Returns max clock in kHz on success or 0 if max clock not defined - */ -int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], - const u8 port_cap[4]) -{ - int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; - bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & - DP_DETAILED_CAP_INFO_AVAILABLE; - - if (!detailed_cap_info) - return 0; - - switch (type) { - case DP_DS_PORT_TYPE_VGA: - return port_cap[1] * 8 * 1000; - case DP_DS_PORT_TYPE_DVI: - case DP_DS_PORT_TYPE_HDMI: - case DP_DS_PORT_TYPE_DP_DUALMODE: - return port_cap[1] * 2500; - default: - return 0; - } -} -EXPORT_SYMBOL(drm_dp_downstream_max_clock); - -/** - * drm_dp_downstream_max_bpc() - extract branch device max - * bits per component - * @dpcd: DisplayPort configuration data - * @port_cap: port capabilities - * - * 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]) -{ - int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; - bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & - DP_DETAILED_CAP_INFO_AVAILABLE; - int bpc; - - if (!detailed_cap_info) - return 0; - - switch (type) { - case DP_DS_PORT_TYPE_VGA: - case DP_DS_PORT_TYPE_DVI: - case DP_DS_PORT_TYPE_HDMI: - case DP_DS_PORT_TYPE_DP_DUALMODE: - bpc = port_cap[2] & DP_DS_MAX_BPC_MASK; - - switch (bpc) { - case DP_DS_8BPC: - return 8; - case DP_DS_10BPC: - return 10; - case DP_DS_12BPC: - return 12; - case DP_DS_16BPC: - return 16; - } - /* fall through */ - default: - return 0; - } -} -EXPORT_SYMBOL(drm_dp_downstream_max_bpc); - -/** - * 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 - * @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], 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 = dpcd[DP_DOWNSTREAMPORT_PRESENT] & - DP_DWN_STRM_PORT_PRESENT; - - 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_clock(dpcd, port_cap); - - if (clk > 0) { - if (type == DP_DS_PORT_TYPE_VGA) - seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk); - else - seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk); - } - - bpc = drm_dp_downstream_max_bpc(dpcd, port_cap); - - if (bpc > 0) - seq_printf(m, "\t\tMax bpc: %d\n", bpc); - } -} -EXPORT_SYMBOL(drm_dp_downstream_debug); - -/* - * 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("transaction timed out\n"); - else - DRM_DEBUG_KMS("transaction failed: %d\n", 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("native nack (result=%d, size=%zu)\n", ret, msg->size); - return -EREMOTEIO; - - case DP_AUX_NATIVE_REPLY_DEFER: - DRM_DEBUG_KMS("native defer\n"); - /* - * 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("invalid native reply %#04x\n", 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("I2C nack (result=%d, size=%zu)\n", - ret, msg->size); - aux->i2c_nack_count++; - return -EREMOTEIO; - - case DP_AUX_I2C_REPLY_DEFER: - DRM_DEBUG_KMS("I2C defer\n"); - /* 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("invalid I2C reply %#04x\n", msg->reply); - return -EREMOTEIO; - } - } - - DRM_DEBUG_KMS("too many retries, giving up\n"); - 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("Partial I2C reply: requested %zu bytes got %d bytes\n", - 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("Get CRC failed after retrying: %d\n", - ret); - continue; - } else if (ret) { - DRM_DEBUG_KMS("Failed to get a CRC: %d\n", 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_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. - * - * 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) }, -}; - -#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 - -/** - * drm_dp_read_desc - read sink/branch descriptor from DPCD - * @aux: DisplayPort AUX channel - * @desc: Device decriptor 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("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", - 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); |