diff --git a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c index 3dd10412d14760..5a8b978c64158d 100644 --- a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c +++ b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c @@ -19,6 +19,10 @@ #include #include +/* T3 VCC to HPD high is max 200 ms */ +#define HPD_MAX_MS 200 +#define HPD_MAX_US (HPD_MAX_MS * 1000) + struct atana33xc20_panel { struct drm_panel base; bool prepared; @@ -30,6 +34,7 @@ struct atana33xc20_panel { struct regulator *supply; struct gpio_desc *el_on3_gpio; + struct drm_dp_aux *aux; struct edid *edid; @@ -79,7 +84,7 @@ static int atana33xc20_suspend(struct device *dev) static int atana33xc20_resume(struct device *dev) { struct atana33xc20_panel *p = dev_get_drvdata(dev); - bool hpd_asserted = false; + int hpd_asserted; int ret; /* T12 (Power off time) is min 500 ms */ @@ -90,23 +95,41 @@ static int atana33xc20_resume(struct device *dev) return ret; p->powered_on_time = ktime_get(); - /* - * Handle HPD. Note: if HPD is hooked up to a dedicated pin on the - * eDP controller then "no_hpd" will be false _and_ "hpd_gpio" will be - * NULL. It's up to the controller driver to wait for HPD after - * preparing the panel in that case. - */ if (p->no_hpd) { - /* T3 VCC to HPD high is max 200 ms */ - msleep(200); - } else if (p->hpd_gpio) { + msleep(HPD_MAX_MS); + return 0; + } + + if (p->hpd_gpio) { ret = readx_poll_timeout(gpiod_get_value_cansleep, p->hpd_gpio, hpd_asserted, hpd_asserted, - 1000, 200000); - if (!hpd_asserted) - dev_warn(dev, "Timeout waiting for HPD\n"); + 1000, HPD_MAX_US); + if (hpd_asserted < 0) + ret = hpd_asserted; + + if (ret) + dev_warn(dev, "Error waiting for HPD GPIO: %d\n", ret); + + return ret; } + if (p->aux->wait_hpd_asserted) { + ret = p->aux->wait_hpd_asserted(p->aux, HPD_MAX_US); + + if (ret) + dev_warn(dev, "Controller error waiting for HPD: %d\n", ret); + + return ret; + } + + /* + * Note that it's possible that no_hpd is false, hpd_gpio is + * NULL, and wait_hpd_asserted is NULL. This is because + * wait_hpd_asserted() is optional even if HPD is hooked up to + * a dedicated pin on the eDP controller. In this case we just + * assume that the controller driver will wait for HPD at the + * right times. + */ return 0; } @@ -263,6 +286,8 @@ static int atana33xc20_probe(struct dp_aux_ep_device *aux_ep) return -ENOMEM; dev_set_drvdata(dev, panel); + panel->aux = aux_ep->aux; + panel->supply = devm_regulator_get(dev, "power"); if (IS_ERR(panel->supply)) return dev_err_probe(dev, PTR_ERR(panel->supply),