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author | Tomeu Vizoso <tomeu.vizoso@collabora.com> | 2017-03-03 14:39:34 +0100 |
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committer | Sean Paul <seanpaul@chromium.org> | 2017-03-06 12:14:27 -0500 |
commit | 79c1da7c3bf74be9b1dae9450ef79f32dd22def6 (patch) | |
tree | 4d58929baaa06ab1820bb4c522eb3d5a1add04db /drivers/gpu/drm/drm_dp_helper.c | |
parent | 4bb310fd9eea254b68b2f48b376fe149f65e3fbb (diff) | |
download | linux-79c1da7c3bf74be9b1dae9450ef79f32dd22def6.tar.gz linux-79c1da7c3bf74be9b1dae9450ef79f32dd22def6.tar.bz2 linux-79c1da7c3bf74be9b1dae9450ef79f32dd22def6.zip |
drm/dp: add helpers for capture of frame CRCs
Adds helpers for starting and stopping capture of frame CRCs through the
DPCD. When capture is on, a worker waits for vblanks and retrieves the
frame CRC to put it in the queue on the CRTC that is using the
eDP connector, so it's passed to userspace.
v2: Reuse drm_crtc_wait_one_vblank
Update locking, as drm_crtc_add_crc_entry now takes the lock
v3: Don't call wake_up_interruptible directly, that's now done in
drm_crtc_add_crc_entry.
v4: Style fixes (Sean Paul)
Reworked retry of CRC reads (Sean Paul)
Flush worker after stopping CRC generationa (Sean Paul)
v5: Move back to make the retry explicitly once
v6: Set and use the drm_crtc backpointer (Sean Paul)
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170303133936.14964-3-tomeu.vizoso@collabora.com
Diffstat (limited to 'drivers/gpu/drm/drm_dp_helper.c')
-rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 68908c1d5ca1..c40cfe2e63ab 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -981,6 +981,78 @@ static const struct i2c_lock_operations drm_dp_i2c_lock_ops = { .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 @@ -993,6 +1065,7 @@ static const struct i2c_lock_operations drm_dp_i2c_lock_ops = { void drm_dp_aux_init(struct drm_dp_aux *aux) { mutex_init(&aux->hw_mutex); + INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work); aux->ddc.algo = &drm_dp_i2c_algo; aux->ddc.algo_data = aux; @@ -1081,3 +1154,56 @@ int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]) EXPORT_SYMBOL(drm_dp_psr_setup_time); #undef PSR_SETUP_TIME + +/** + * drm_dp_start_crc() - start capture of frame CRCs + * @aux: DisplayPort AUX channel + * + * 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); |