diff options
Diffstat (limited to 'drivers/gpu/drm/display/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/display/drm_dp_helper.c | 246 |
1 files changed, 244 insertions, 2 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index 6ee51003de3c..dbce1c3f4969 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -22,15 +22,16 @@ #include <linux/backlight.h> #include <linux/delay.h> +#include <linux/dynamic_debug.h> #include <linux/errno.h> #include <linux/i2c.h> #include <linux/init.h> +#include <linux/iopoll.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/sched.h> #include <linux/seq_file.h> #include <linux/string_helpers.h> -#include <linux/dynamic_debug.h> #include <drm/display/drm_dp_helper.h> #include <drm/display/drm_dp_mst_helper.h> @@ -458,6 +459,64 @@ void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux, } EXPORT_SYMBOL(drm_dp_lttpr_link_train_channel_eq_delay); +/** + * drm_dp_lttpr_wake_timeout_setup() - Grant extended time for sink to wake up + * @aux: The DP AUX channel to use + * @transparent_mode: This is true if lttpr is in transparent mode + * + * This function checks if the sink needs any extended wake time, if it does + * it grants this request. Post this setup the source device can keep trying + * the Aux transaction till the granted wake timeout. + * If this function is not called all Aux transactions are expected to take + * a default of 1ms before they throw an error. + */ +void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode) +{ + u8 val = 1; + int ret; + + if (transparent_mode) { + static const u8 timeout_mapping[] = { + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_1_MS] = 1, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_20_MS] = 20, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_40_MS] = 40, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_60_MS] = 60, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_80_MS] = 80, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_100_MS] = 100, + }; + + ret = drm_dp_dpcd_readb(aux, DP_EXTENDED_DPRX_SLEEP_WAKE_TIMEOUT_REQUEST, &val); + if (ret != 1) { + drm_dbg_kms(aux->drm_dev, + "Failed to read Extended sleep wake timeout request\n"); + return; + } + + val = (val < sizeof(timeout_mapping) && timeout_mapping[val]) ? + timeout_mapping[val] : 1; + + if (val > 1) + drm_dp_dpcd_writeb(aux, + DP_EXTENDED_DPRX_SLEEP_WAKE_TIMEOUT_GRANT, + DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_GRANTED); + } else { + ret = drm_dp_dpcd_readb(aux, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT, &val); + if (ret != 1) { + drm_dbg_kms(aux->drm_dev, + "Failed to read Extended sleep wake timeout request\n"); + return; + } + + val = (val & DP_EXTENDED_WAKE_TIMEOUT_REQUEST_MASK) ? + (val & DP_EXTENDED_WAKE_TIMEOUT_REQUEST_MASK) * 10 : 1; + + if (val > 1) + drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT, + DP_EXTENDED_WAKE_TIMEOUT_GRANT); + } +} +EXPORT_SYMBOL(drm_dp_lttpr_wake_timeout_setup); + u8 drm_dp_link_rate_to_bw_code(int link_rate) { switch (link_rate) { @@ -779,6 +838,128 @@ int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux, } EXPORT_SYMBOL(drm_dp_dpcd_read_phy_link_status); +static int read_payload_update_status(struct drm_dp_aux *aux) +{ + int ret; + u8 status; + + ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); + if (ret < 0) + return ret; + + return status; +} + +/** + * drm_dp_dpcd_write_payload() - Write Virtual Channel information to payload table + * @aux: DisplayPort AUX channel + * @vcpid: Virtual Channel Payload ID + * @start_time_slot: Starting time slot + * @time_slot_count: Time slot count + * + * Write the Virtual Channel payload allocation table, checking the payload + * update status and retrying as necessary. + * + * Returns: + * 0 on success, negative error otherwise + */ +int drm_dp_dpcd_write_payload(struct drm_dp_aux *aux, + int vcpid, u8 start_time_slot, u8 time_slot_count) +{ + u8 payload_alloc[3], status; + int ret; + int retries = 0; + + drm_dp_dpcd_writeb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, + DP_PAYLOAD_TABLE_UPDATED); + + payload_alloc[0] = vcpid; + payload_alloc[1] = start_time_slot; + payload_alloc[2] = time_slot_count; + + ret = drm_dp_dpcd_write(aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3); + if (ret != 3) { + drm_dbg_kms(aux->drm_dev, "failed to write payload allocation %d\n", ret); + goto fail; + } + +retry: + ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, "failed to read payload table status %d\n", ret); + goto fail; + } + + if (!(status & DP_PAYLOAD_TABLE_UPDATED)) { + retries++; + if (retries < 20) { + usleep_range(10000, 20000); + goto retry; + } + drm_dbg_kms(aux->drm_dev, "status not set after read payload table status %d\n", + status); + ret = -EINVAL; + goto fail; + } + ret = 0; +fail: + return ret; +} +EXPORT_SYMBOL(drm_dp_dpcd_write_payload); + +/** + * drm_dp_dpcd_clear_payload() - Clear the entire VC Payload ID table + * @aux: DisplayPort AUX channel + * + * Clear the entire VC Payload ID table. + * + * Returns: 0 on success, negative error code on errors. + */ +int drm_dp_dpcd_clear_payload(struct drm_dp_aux *aux) +{ + return drm_dp_dpcd_write_payload(aux, 0, 0, 0x3f); +} +EXPORT_SYMBOL(drm_dp_dpcd_clear_payload); + +/** + * drm_dp_dpcd_poll_act_handled() - Poll for ACT handled status + * @aux: DisplayPort AUX channel + * @timeout_ms: Timeout in ms + * + * Try waiting for the sink to finish updating its payload table by polling for + * the ACT handled bit of DP_PAYLOAD_TABLE_UPDATE_STATUS for up to @timeout_ms + * milliseconds, defaulting to 3000 ms if 0. + * + * Returns: + * 0 if the ACT was handled in time, negative error code on failure. + */ +int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms) +{ + int ret, status; + + /* default to 3 seconds, this is arbitrary */ + timeout_ms = timeout_ms ?: 3000; + + ret = readx_poll_timeout(read_payload_update_status, aux, status, + status & DP_PAYLOAD_ACT_HANDLED || status < 0, + 200, timeout_ms * USEC_PER_MSEC); + if (ret < 0 && status >= 0) { + drm_err(aux->drm_dev, "Failed to get ACT after %d ms, last status: %02x\n", + timeout_ms, status); + return -EINVAL; + } else if (status < 0) { + /* + * Failure here isn't unexpected - the hub may have + * just been unplugged + */ + drm_dbg_kms(aux->drm_dev, "Failed to read payload table status: %d\n", status); + return status; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_dpcd_poll_act_handled); + static bool is_edid_digital_input_dp(const struct drm_edid *drm_edid) { /* FIXME: get rid of drm_edid_raw() */ @@ -2421,7 +2602,7 @@ u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) { u8 bpp_increment_dpcd = dsc_dpcd[DP_DSC_BITS_PER_PIXEL_INC - DP_DSC_SUPPORT]; - switch (bpp_increment_dpcd) { + switch (bpp_increment_dpcd & DP_DSC_BITS_PER_PIXEL_MASK) { case DP_DSC_BITS_PER_PIXEL_1_16: return 16; case DP_DSC_BITS_PER_PIXEL_1_8: @@ -2695,6 +2876,67 @@ int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) EXPORT_SYMBOL(drm_dp_lttpr_max_link_rate); /** + * drm_dp_lttpr_set_transparent_mode() - set the LTTPR in transparent mode + * @aux: DisplayPort AUX channel + * @enable: Enable or disable transparent mode + * + * Returns: 0 on success or a negative error code on failure. + */ +int drm_dp_lttpr_set_transparent_mode(struct drm_dp_aux *aux, bool enable) +{ + u8 val = enable ? DP_PHY_REPEATER_MODE_TRANSPARENT : + DP_PHY_REPEATER_MODE_NON_TRANSPARENT; + int ret = drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_MODE, val); + + if (ret < 0) + return ret; + + return (ret == 1) ? 0 : -EIO; +} +EXPORT_SYMBOL(drm_dp_lttpr_set_transparent_mode); + +/** + * drm_dp_lttpr_init() - init LTTPR transparency mode according to DP standard + * @aux: DisplayPort AUX channel + * @lttpr_count: Number of LTTPRs. Between 0 and 8, according to DP standard. + * Negative error code for any non-valid number. + * See drm_dp_lttpr_count(). + * + * Returns: 0 on success or a negative error code on failure. + */ +int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count) +{ + int ret; + + if (!lttpr_count) + return 0; + + /* + * See DP Standard v2.0 3.6.6.1 about the explicit disabling of + * non-transparent mode and the disable->enable non-transparent mode + * sequence. + */ + ret = drm_dp_lttpr_set_transparent_mode(aux, true); + if (ret) + return ret; + + if (lttpr_count < 0) + return -ENODEV; + + if (drm_dp_lttpr_set_transparent_mode(aux, false)) { + /* + * Roll-back to transparent mode if setting non-transparent + * mode has failed + */ + drm_dp_lttpr_set_transparent_mode(aux, true); + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_lttpr_init); + +/** * drm_dp_lttpr_max_lane_count - get the maximum lane count supported by all LTTPRs * @caps: LTTPR common capabilities * |