[PATCH v5 15/17] drm: bridge: analogix/dp: try force hpd after plug in lookup failed

Yakir Yang
2015-09-22T08:02:55Z

Some edp screen do not have hpd signal, so we can't just return
failed when hpd plug in detect failed.

This is an hardware property, so we need add a devicetree property
"analogix,need-force-hpd" to indicate this sutiation.

Signed-off-by: Yakir Yang <ykk@rock-chips.com>
---
Changes in v5: None
Changes in v4: None
Changes in v3:
- Add "analogix,need-force-hpd" to indicate whether driver need foce
hpd when hpd detect failed.

Changes in v2: None

.../devicetree/bindings/drm/bridge/analogix_dp.txt | 4 ++-
.../bindings/video/analogix_dp-rockchip.txt | 1 +
.../devicetree/bindings/video/exynos_dp.txt | 1 +
drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 36 +++++++++++++++++++---
drivers/gpu/drm/bridge/analogix/analogix_dp_core.h | 2 ++
drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 9 ++++++
6 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/drm/bridge/analogix_dp.txt b/Documentation/devicetree/bindings/drm/bridge/analogix_dp.txt
index f54dc3e..c310367 100644
--- a/Documentation/devicetree/bindings/drm/bridge/analogix_dp.txt
+++ b/Documentation/devicetree/bindings/drm/bridge/analogix_dp.txt
@@ -22,6 +22,9 @@ Required properties for dp-controller:
from general PHY binding: Should be "dp".

Optional properties for dp-controller:
+ -analogix,need-force-hpd:
+ Indicate driver need force hpd when hpd detect failed, this
+ is used for some eDP screen which don't have hpd signal.
-hpd-gpios:
Hotplug detect GPIO.
Indicates which GPIO should be used for hotplug detection
@@ -31,7 +34,6 @@ Optional properties for dp-controller:
* Documentation/devicetree/bindings/video/exynos_dp.txt
* Documentation/devicetree/bindings/video/analogix_dp-rockchip.txt

-
[1]: Documentation/devicetree/bindings/media/video-interfaces.txt
-------------------------------------------------------------------------------

diff --git a/Documentation/devicetree/bindings/video/analogix_dp-rockchip.txt b/Documentation/devicetree/bindings/video/analogix_dp-rockchip.txt
index ec93917..be18388 100644
--- a/Documentation/devicetree/bindings/video/analogix_dp-rockchip.txt
+++ b/Documentation/devicetree/bindings/video/analogix_dp-rockchip.txt
@@ -31,6 +31,7 @@ For the below properties, please refer to Analogix DP binding document:
- phys (required)
- phy-names (required)
- hpd-gpios (optional)
+- analogix,need-force-hpd (optional)
-------------------------------------------------------------------------------

Example:
diff --git a/Documentation/devicetree/bindings/video/exynos_dp.txt b/Documentation/devicetree/bindings/video/exynos_dp.txt
index ea03b3a..4f06e80 100644
--- a/Documentation/devicetree/bindings/video/exynos_dp.txt
+++ b/Documentation/devicetree/bindings/video/exynos_dp.txt
@@ -41,6 +41,7 @@ For the below properties, please refer to Analogix DP binding document:
-phys (required)
-phy-names (required)
-hpd-gpios (optional)
+ -analogix,need-force-hpd (optional)
-video interfaces (optional)

Deprecated properties for DisplayPort:
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 3efae33..7e83738 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -59,15 +59,38 @@ static int analogix_dp_detect_hpd(struct analogix_dp_device *dp)
{
int timeout_loop = 0;

- while (analogix_dp_get_plug_in_status(dp) != 0) {
+ while (timeout_loop < DP_TIMEOUT_LOOP_COUNT) {
+ if (analogix_dp_get_plug_in_status(dp) == 0)
+ return 0;
+
timeout_loop++;
- if (timeout_loop > DP_TIMEOUT_LOOP_COUNT) {
- dev_err(dp->dev, "failed to get hpd plug status\n");
- return -ETIMEDOUT;
- }
usleep_range(10, 11);
}

+ /*
+ * Some edp screen do not have hpd signal, so we can't just
+ * return failed when hpd plug in detect failed, DT property
+ * "need-force-hpd" would indicate whether driver need this.
+ */
+ if (!dp->need_force_hpd)
+ return -ETIMEDOUT;
+
+ /*
+ * The eDP TRM indicate that if HPD_STATUS(RO) is 0, AUX CH
+ * will not work, so we need to give a force hpd action to
+ * set HPD_STATUS manually.
+ */
+ dev_dbg(dp->dev, "failed to get hpd plug status, try to force hpd\n");
+
+ analogix_dp_force_hpd(dp);
+
+ if (analogix_dp_get_plug_in_status(dp) != 0) {
+ dev_err(dp->dev, "failed to get hpd plug in status\n");
+ return -EINVAL;
+ }
+
+ dev_dbg(dp->dev, "success to get plug in status after force hpd\n");
+
return 0;
}

@@ -1243,6 +1266,9 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
if (IS_ERR(dp->reg_base))
return PTR_ERR(dp->reg_base);

+ dp->need_force_hpd =
+ of_property_read_bool(dev->of_node, "analogix,need-force-hpd");
+
dp->hpd_gpio = of_get_named_gpio(dev->of_node, "hpd-gpios", 0);
if (!gpio_is_valid(dp->hpd_gpio))
dp->hpd_gpio = of_get_named_gpio(dev->of_node,
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
index f4cb799..3a136b8 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
@@ -160,6 +160,7 @@ struct analogix_dp_device {
struct phy *phy;
int dpms_mode;
int hpd_gpio;
+ bool need_force_hpd;

struct analogix_dp_plat_data *plat_data;
};
@@ -180,6 +181,7 @@ void analogix_dp_set_analog_power_down(struct analogix_dp_device *dp,
bool enable);
void analogix_dp_init_analog_func(struct analogix_dp_device *dp);
void analogix_dp_init_hpd(struct analogix_dp_device *dp);
+void analogix_dp_force_hpd(struct analogix_dp_device *dp);
enum dp_irq_type analogix_dp_get_irq_type(struct analogix_dp_device *dp);
void analogix_dp_clear_hotplug_interrupts(struct analogix_dp_device *dp);
void analogix_dp_reset_aux(struct analogix_dp_device *dp);
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
index 21a3287..c7e2959 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
@@ -365,6 +365,15 @@ void analogix_dp_init_hpd(struct analogix_dp_device *dp)
writel(reg, dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
}

+void analogix_dp_force_hpd(struct analogix_dp_device *dp)
+{
+ u32 reg;
+
+ reg = readl(dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
+ reg = (F_HPD | HPD_CTRL);
+ writel(reg, dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
+}
+
enum dp_irq_type analogix_dp_get_irq_type(struct analogix_dp_device *dp)
{
u32 reg;
--
1.9.1