On 18/04/2022 20:17, Douglas Anderson wrote:
Sometimes it's useful for users of the DP AUX bus (like panels) to be able to poll HPD. Let's add a callback that allows DP AUX busses drivers to provide this.
Suggested-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Signed-off-by: Douglas Anderson dianders@chromium.org
Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org
Left Dmitry's Reviewed-by tag off since patch changed enough.
(no changes since v2)
Changes in v2:
Change is_hpd_asserted() to wait_hpd_asserted()
include/drm/dp/drm_dp_helper.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)
diff --git a/include/drm/dp/drm_dp_helper.h b/include/drm/dp/drm_dp_helper.h index 53d1e722f4de..0940c415db8c 100644 --- a/include/drm/dp/drm_dp_helper.h +++ b/include/drm/dp/drm_dp_helper.h @@ -2035,6 +2035,32 @@ struct drm_dp_aux { ssize_t (*transfer)(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg);
- /**
* @wait_hpd_asserted: wait for HPD to be asserted** This is mainly useful for eDP panels drivers to wait for an eDP* panel to finish powering on. This is an optional function.** This function will efficiently wait for up to `wait_us` microseconds* for HPD to be asserted and might sleep.** This function returns 0 if HPD was asserted or -ETIMEDOUT if time* expired and HPD wasn't asserted. This function should not print* timeout errors to the log.** The semantics of this function are designed to match the* readx_poll_timeout() function. That means a `wait_us` of 0 means* to wait forever. If you want to do a quick poll you could pass 1* for `wait_us`.** NOTE: this function specifically reports the state of the HPD pin* that's associated with the DP AUX channel. This is different from* the HPD concept in much of the rest of DRM which is more about* physical presence of a display. For eDP, for instance, a display is* assumed always present even if the HPD pin is deasserted.*/- int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
- /**
*/
- @i2c_nack_count: Counts I2C NACKs, used for DP validation.