From: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
Certain bridge chips use a GPIO to indicate the cable status instead
of the I_DP_HPD pin. This adds an optional device-tree property,
"samsung,hpd-gpio", to the exynos-dp controller which indicates that
the specified GPIO should be used for hotplug detection.
The GPIO is then set up as an edge-triggered interrupt where the
rising edge indicates hotplug-in and the falling edge indicates hotplug-out.
Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
Signed-off-by: Rahul Sharma <rahul.sharma@xxxxxxxxxxx>
Signed-off-by: Ajay Kumar <ajaykumar.rs@xxxxxxxxxxx>
---
Changes since V1:
Address reiew comments from Jingoo Han
.../devicetree/bindings/video/exynos_dp.txt | 4 ++
drivers/gpu/drm/exynos/exynos_dp_core.c | 32 ++++++++++++--
drivers/gpu/drm/exynos/exynos_dp_core.h | 1 +
drivers/gpu/drm/exynos/exynos_dp_reg.c | 44 ++++++++++++++------
4 files changed, 66 insertions(+), 15 deletions(-)
diff --git a/Documentation/devicetree/bindings/video/exynos_dp.txt b/Documentation/devicetree/bindings/video/exynos_dp.txt
index 57ccdde..53dbccf 100644
--- a/Documentation/devicetree/bindings/video/exynos_dp.txt
+++ b/Documentation/devicetree/bindings/video/exynos_dp.txt
@@ -62,6 +62,10 @@ Optional properties for dp-controller:
-hsync-active-high:
HSYNC polarity configuration.
High if defined, Low if not defined
+ -samsung,hpd-gpio:
+ Hotplug detect GPIO.
+ Indicates which GPIO should be used for hotplug
+ detection
Example:
diff --git a/drivers/gpu/drm/exynos/exynos_dp_core.c b/drivers/gpu/drm/exynos/exynos_dp_core.c
index 1cc3981..18fd9c5 100644
--- a/drivers/gpu/drm/exynos/exynos_dp_core.c
+++ b/drivers/gpu/drm/exynos/exynos_dp_core.c
@@ -18,6 +18,8 @@
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio.h>
#include <linux/component.h>
#include <linux/phy/phy.h>
#include <video/of_display_timing.h>
@@ -1226,6 +1228,7 @@ static int exynos_dp_bind(struct device *dev, struct device *master, void *data)
struct drm_device *drm_dev = data;
struct resource *res;
struct exynos_dp_device *dp;
+ unsigned int irq_flags;
int ret = 0;
@@ -1265,7 +1268,30 @@ static int exynos_dp_bind(struct device *dev, struct device *master, void *data)
if (IS_ERR(dp->reg_base))
return PTR_ERR(dp->reg_base);
- dp->irq = platform_get_irq(pdev, 0);
+ dp->hpd_gpio = of_get_named_gpio(dev->of_node, "samsung,hpd-gpio", 0);
+
+ if (gpio_is_valid(dp->hpd_gpio)) {
+ /*
+ * Set up the hotplug GPIO from the device tree as an interrupt.
+ * Simply specifying a different interrupt in the device tree
+ * doesn't work since we handle hotplug rather differently when
+ * using a GPIO. We also need the actual GPIO specifier so
+ * that we can get the current state of the GPIO.
+ */
+ ret = devm_gpio_request_one(&pdev->dev, dp->hpd_gpio, GPIOF_IN,
+ "hpd_gpio");
+ if (ret) {
+ dev_err(&pdev->dev, "failed to get hpd gpio\n");
+ return ret;
+ }
+ dp->irq = gpio_to_irq(dp->hpd_gpio);
+ irq_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
+ } else {
+ dp->hpd_gpio = -ENODEV;
+ dp->irq = platform_get_irq(pdev, 0);
+ irq_flags = 0;
+ }
+
if (dp->irq == -ENXIO) {
dev_err(&pdev->dev, "failed to get irq\n");
return -ENODEV;
@@ -1277,8 +1303,8 @@ static int exynos_dp_bind(struct device *dev, struct device *master, void *data)
exynos_dp_init_dp(dp);
- ret = devm_request_irq(&pdev->dev, dp->irq, exynos_dp_irq_handler, 0,
- "exynos-dp", dp);
+ ret = devm_request_irq(&pdev->dev, dp->irq, exynos_dp_irq_handler,
+ irq_flags, "exynos-dp", dp);
if (ret) {
dev_err(&pdev->dev, "failed to request irq\n");
return ret;
diff --git a/drivers/gpu/drm/exynos/exynos_dp_core.h b/drivers/gpu/drm/exynos/exynos_dp_core.h
index d6a900d..56fa43e 100644
--- a/drivers/gpu/drm/exynos/exynos_dp_core.h
+++ b/drivers/gpu/drm/exynos/exynos_dp_core.h
@@ -159,6 +159,7 @@ struct exynos_dp_device {
struct work_struct hotplug_work;
struct phy *phy;
int dpms_mode;
+ int hpd_gpio;
struct exynos_drm_panel_info panel;
};
diff --git a/drivers/gpu/drm/exynos/exynos_dp_reg.c b/drivers/gpu/drm/exynos/exynos_dp_reg.c
index b70da50..79291a2 100644
--- a/drivers/gpu/drm/exynos/exynos_dp_reg.c
+++ b/drivers/gpu/drm/exynos/exynos_dp_reg.c
@@ -13,6 +13,7 @@
#include <linux/device.h>
#include <linux/io.h>
#include <linux/delay.h>
+#include <linux/gpio.h>
#include "exynos_dp_core.h"
#include "exynos_dp_reg.h"
@@ -326,6 +327,9 @@ void exynos_dp_clear_hotplug_interrupts(struct exynos_dp_device *dp)
{
u32 reg;
+ if (gpio_is_valid(dp->hpd_gpio))
+ return;
+
reg = HOTPLUG_CHG | HPD_LOST | PLUG;
writel(reg, dp->reg_base + EXYNOS_DP_COMMON_INT_STA_4);
@@ -337,6 +341,9 @@ void exynos_dp_init_hpd(struct exynos_dp_device *dp)
{
u32 reg;
+ if (gpio_is_valid(dp->hpd_gpio))
+ return;
+
exynos_dp_clear_hotplug_interrupts(dp);
reg = readl(dp->reg_base + EXYNOS_DP_SYS_CTL_3);
@@ -348,19 +355,27 @@ enum dp_irq_type exynos_dp_get_irq_type(struct exynos_dp_device *dp)
{
u32 reg;
- /* Parse hotplug interrupt status register */
- reg = readl(dp->reg_base + EXYNOS_DP_COMMON_INT_STA_4);
+ if (gpio_is_valid(dp->hpd_gpio)) {
+ reg = gpio_get_value(dp->hpd_gpio);
+ if (reg)
+ return DP_IRQ_TYPE_HP_CABLE_IN;
+ else
+ return DP_IRQ_TYPE_HP_CABLE_OUT;
+ } else {
+ /* Parse hotplug interrupt status register */
+ reg = readl(dp->reg_base + EXYNOS_DP_COMMON_INT_STA_4);
- if (reg & PLUG)
- return DP_IRQ_TYPE_HP_CABLE_IN;
+ if (reg & PLUG)
+ return DP_IRQ_TYPE_HP_CABLE_IN;
- if (reg & HPD_LOST)
- return DP_IRQ_TYPE_HP_CABLE_OUT;
+ if (reg & HPD_LOST)
+ return DP_IRQ_TYPE_HP_CABLE_OUT;
- if (reg & HOTPLUG_CHG)
- return DP_IRQ_TYPE_HP_CHANGE;
+ if (reg & HOTPLUG_CHG)
+ return DP_IRQ_TYPE_HP_CHANGE;
- return DP_IRQ_TYPE_UNKNOWN;
+ return DP_IRQ_TYPE_UNKNOWN;
+ }
}
void exynos_dp_reset_aux(struct exynos_dp_device *dp)
@@ -402,9 +417,14 @@ int exynos_dp_get_plug_in_status(struct exynos_dp_device *dp)
{
u32 reg;
- reg = readl(dp->reg_base + EXYNOS_DP_SYS_CTL_3);
- if (reg & HPD_STATUS)
- return 0;
+ if (gpio_is_valid(dp->hpd_gpio)) {
+ if (gpio_get_value(dp->hpd_gpio))
+ return 0;
+ } else {
+ reg = readl(dp->reg_base + EXYNOS_DP_SYS_CTL_3);
+ if (reg & HPD_STATUS)
+ return 0;
+ }
return -EINVAL;
}
--
1.7.9.5
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