[PATCH 4/4] drm: bridge: anx7688: Support bypass GPIO feature

[Hsin-Yi Wang]

Support optional feature: bypass GPIO.

Get GPIO status in irq handler. If GPIO is active, mode_fixup would be
bypassed.

Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
---
 drivers/gpu/drm/bridge/analogix-anx7688.c | 57 +++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/bridge/analogix-anx7688.c b/drivers/gpu/drm/bridge/analogix-anx7688.c
index 5a3a2251c1c5..1d09db2cf8e9 100644
--- a/drivers/gpu/drm/bridge/analogix-anx7688.c
+++ b/drivers/gpu/drm/bridge/analogix-anx7688.c
@@ -5,11 +5,16 @@
  * Copyright 2016 Google LLC
  */
 
+#include <linux/gpio.h>
 #include <linux/i2c.h>
+#include <linux/interrupt.h>
 #include <linux/module.h>
+#include <linux/of_gpio.h>
 #include <linux/regmap.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_probe_helper.h>
 
 /* Register addresses */
 #define VENDOR_ID_REG 0x00
@@ -31,6 +36,9 @@ struct anx7688 {
 	struct i2c_client *client;
 	struct regmap *regmap;
 
+	struct gpio_desc *gpiod_bypass;
+	int bypass;
+
 	bool filter;
 };
 
@@ -49,6 +57,10 @@ static bool anx7688_bridge_mode_fixup(struct drm_bridge *bridge,
 	int totalbw, requiredbw;
 	int ret;
 
+	/* bypass anx mode fixup */
+	if (anx7688->bypass)
+		return true;
+
 	if (!anx7688->filter)
 		return true;
 
@@ -93,6 +105,19 @@ static const struct drm_bridge_funcs anx7688_bridge_funcs = {
 	.mode_fixup	= anx7688_bridge_mode_fixup,
 };
 
+static irqreturn_t gpio_display_mux_det_threaded_handler(int unused, void *data)
+{
+	struct anx7688 *anx7688 = data;
+
+	anx7688->bypass = gpiod_get_value(anx7688->gpiod_bypass);
+	dev_dbg(&anx7688->client->dev, "Interrupt %d!\n", anx7688->bypass);
+
+	if (anx7688->bridge.dev)
+		drm_kms_helper_hotplug_event(anx7688->bridge.dev);
+
+	return IRQ_HANDLED;
+}
+
 static const struct regmap_config anx7688_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
@@ -156,6 +181,38 @@ static int anx7688_i2c_probe(struct i2c_client *client,
 			 buffer[0], buffer[1]);
 	}
 
+	/* Optional bypass-gpios */
+	anx7688->gpiod_bypass = devm_gpiod_get_optional(dev, "bypass",
+							GPIOD_IN);
+	if (IS_ERR(anx7688->gpiod_bypass)) {
+		ret = PTR_ERR(anx7688->gpiod_bypass);
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "bypass-gpios assigned failed\n");
+		return ret;
+	}
+	if (anx7688->gpiod_bypass) {
+		int irq;
+
+		irq = gpiod_to_irq(anx7688->gpiod_bypass);
+		if (irq < 0) {
+			dev_err(dev, "Failed to get output irq %d\n", irq);
+			return -ENODEV;
+		}
+
+		anx7688->bypass = gpiod_get_value(anx7688->gpiod_bypass);
+
+		ret = devm_request_threaded_irq(dev, irq, NULL,
+				gpio_display_mux_det_threaded_handler,
+				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
+				IRQF_ONESHOT,
+				"gpio-display-mux-det", anx7688);
+		if (ret) {
+			dev_err(dev,
+				"Failed to request MUX_DET threaded irq\n");
+			return ret;
+		}
+	}
+
 	anx7688->bridge.funcs = &anx7688_bridge_funcs;
 	drm_bridge_add(&anx7688->bridge);
 
-- 
2.24.0.393.g34dc348eaf-goog