drm/msm/hdmi: Convert to use GPIO descriptors

This switches the MSM HDMI code to use GPIO descriptors.
Normally we would fetch the GPIOs from the device with the
flags GPIOD_IN or GPIOD_OUT_[LOW|HIGH] to set up the lines
immediately, but since the code seems eager to actively
drive the lines high/low when turning HDMI on and off, we
just fetch the GPIOs as-is and keep the code explicitly
driving them.

The old code would try legacy bindings (GPIOs without any
"-gpios" suffix) but this has been moved to the gpiolib
as a quirk by the previous patch.

Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/hdmi/hdmi.c

@@ -425,38 +425,6 @@ static const struct {
 	{ "qcom,hdmi-tx-mux-lpm", true, 1, "HDMI_MUX_LPM" },
 };
 
-static int msm_hdmi_get_gpio(struct device_node *of_node, const char *name)
-{
-	int gpio;
-
-	/* try with the gpio names as in the table (downstream bindings) */
-	gpio = of_get_named_gpio(of_node, name, 0);
-	if (gpio < 0) {
-		char name2[32];
-
-		/* try with the gpio names as in the upstream bindings */
-		snprintf(name2, sizeof(name2), "%s-gpios", name);
-		gpio = of_get_named_gpio(of_node, name2, 0);
-		if (gpio < 0) {
-			char name3[32];
-
-			/*
-			 * try again after stripping out the "qcom,hdmi-tx"
-			 * prefix. This is mainly to match "hpd-gpios" used
-			 * in the upstream bindings
-			 */
-			if (sscanf(name2, "qcom,hdmi-tx-%s", name3))
-				gpio = of_get_named_gpio(of_node, name3, 0);
-		}
-
-		if (gpio < 0) {
-			DBG("failed to get gpio: %s (%d)", name, gpio);
-			gpio = -1;
-		}
-	}
-	return gpio;
-}
-
 /*
  * HDMI audio codec callbacks
  */
@@ -582,11 +550,39 @@ static int msm_hdmi_bind(struct device *dev, struct device *master, void *data)
 	hdmi_cfg->qfprom_mmio_name = "qfprom_physical";
 
 	for (i = 0; i < HDMI_MAX_NUM_GPIO; i++) {
-		hdmi_cfg->gpios[i].num = msm_hdmi_get_gpio(of_node,
-						msm_hdmi_gpio_pdata[i].name);
+		const char *name = msm_hdmi_gpio_pdata[i].name;
+		struct gpio_desc *gpiod;
+
+		/*
+		 * We are fetching the GPIO lines "as is" since the connector
+		 * code is enabling and disabling the lines. Until that point
+		 * the power-on default value will be kept.
+		 */
+		gpiod = devm_gpiod_get_optional(dev, name, GPIOD_ASIS);
+		/* This will catch e.g. -PROBE_DEFER */
+		if (IS_ERR(gpiod))
+			return PTR_ERR(gpiod);
+		if (!gpiod) {
+			/* Try a second time, stripping down the name */
+			char name3[32];
+
+			/*
+			 * Try again after stripping out the "qcom,hdmi-tx"
+			 * prefix. This is mainly to match "hpd-gpios" used
+			 * in the upstream bindings.
+			 */
+			if (sscanf(name, "qcom,hdmi-tx-%s", name3))
+				gpiod = devm_gpiod_get_optional(dev, name3, GPIOD_ASIS);
+			if (IS_ERR(gpiod))
+				return PTR_ERR(gpiod);
+			if (!gpiod)
+				DBG("failed to get gpio: %s", name);
+		}
+		hdmi_cfg->gpios[i].gpiod = gpiod;
+		if (gpiod)
+			gpiod_set_consumer_name(gpiod, msm_hdmi_gpio_pdata[i].label);
 		hdmi_cfg->gpios[i].output = msm_hdmi_gpio_pdata[i].output;
 		hdmi_cfg->gpios[i].value = msm_hdmi_gpio_pdata[i].value;
-		hdmi_cfg->gpios[i].label = msm_hdmi_gpio_pdata[i].label;
 	}
 
 	dev->platform_data = hdmi_cfg;

drivers/gpu/drm/msm/hdmi/hdmi.h

@@ -11,6 +11,7 @@
 #include <linux/clk.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
 #include <linux/hdmi.h>
 
 #include "msm_drv.h"
@@ -22,10 +23,9 @@ struct hdmi_phy;
 struct hdmi_platform_config;
 
 struct hdmi_gpio_data {
-	int num;
+	struct gpio_desc *gpiod;
 	bool output;
 	int value;
-	const char *label;
 };
 
 struct hdmi_audio {

drivers/gpu/drm/msm/hdmi/hdmi_connector.c

@@ -5,7 +5,7 @@
  */
 
 #include <linux/delay.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/pinctrl/consumer.h>
 
 #include "msm_kms.h"
@@ -69,30 +69,21 @@ static void msm_hdmi_phy_reset(struct hdmi *hdmi)
 
 static int gpio_config(struct hdmi *hdmi, bool on)
 {
-	struct device *dev = &hdmi->pdev->dev;
 	const struct hdmi_platform_config *config = hdmi->config;
-	int ret, i;
+	int i;
 
 	if (on) {
 		for (i = 0; i < HDMI_MAX_NUM_GPIO; i++) {
 			struct hdmi_gpio_data gpio = config->gpios[i];
 
-			if (gpio.num != -1) {
-				ret = gpio_request(gpio.num, gpio.label);
-				if (ret) {
-					DRM_DEV_ERROR(dev,
-						"'%s'(%d) gpio_request failed: %d\n",
-						gpio.label, gpio.num, ret);
-					goto err;
-				}
-
+			if (gpio.gpiod) {
 				if (gpio.output) {
-					gpio_direction_output(gpio.num,
-							      gpio.value);
+					gpiod_direction_output(gpio.gpiod,
+							       gpio.value);
 				} else {
-					gpio_direction_input(gpio.num);
-					gpio_set_value_cansleep(gpio.num,
-								gpio.value);
+					gpiod_direction_input(gpio.gpiod);
+					gpiod_set_value_cansleep(gpio.gpiod,
+								 gpio.value);
 				}
 			}
 		}
@@ -102,29 +93,20 @@ static int gpio_config(struct hdmi *hdmi, bool on)
 		for (i = 0; i < HDMI_MAX_NUM_GPIO; i++) {
 			struct hdmi_gpio_data gpio = config->gpios[i];
 
-			if (gpio.num == -1)
+			if (!gpio.gpiod)
 				continue;
 
 			if (gpio.output) {
 				int value = gpio.value ? 0 : 1;
 
-				gpio_set_value_cansleep(gpio.num, value);
+				gpiod_set_value_cansleep(gpio.gpiod, value);
 			}
-
-			gpio_free(gpio.num);
 		};
 
 		DBG("gpio off");
 	}
 
 	return 0;
-err:
-	while (i--) {
-		if (config->gpios[i].num != -1)
-			gpio_free(config->gpios[i].num);
-	}
-
-	return ret;
 }
 
 static void enable_hpd_clocks(struct hdmi *hdmi, bool enable)
@@ -312,7 +294,7 @@ static enum drm_connector_status detect_gpio(struct hdmi *hdmi)
 	const struct hdmi_platform_config *config = hdmi->config;
 	struct hdmi_gpio_data hpd_gpio = config->gpios[HPD_GPIO_INDEX];
 
-	return gpio_get_value(hpd_gpio.num) ?
+	return gpiod_get_value(hpd_gpio.gpiod) ?
 			connector_status_connected :
 			connector_status_disconnected;
 }
@@ -331,7 +313,7 @@ static enum drm_connector_status hdmi_connector_detect(
 	 * some platforms may not have hpd gpio. Rely only on the status
 	 * provided by REG_HDMI_HPD_INT_STATUS in this case.
 	 */
-	if (hpd_gpio.num == -1)
+	if (!hpd_gpio.gpiod)
 		return detect_reg(hdmi);
 
 	do {