1 files changed, 317 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/hdmi/hdmi_hpd.c b/drivers/gpu/drm/msm/hdmi/hdmi_hpd.c
new file mode 100644
index 000000000000..75605ddac7c4
--- /dev/null
+++ b/drivers/gpu/drm/msm/hdmi/hdmi_hpd.c
@@ -0,0 +1,317 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2013 Red Hat
+ * Author: Rob Clark <robdclark@gmail.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/pinctrl/consumer.h>
+
+#include "msm_kms.h"
+#include "hdmi.h"
+
+static void msm_hdmi_phy_reset(struct hdmi *hdmi)
+{
+	unsigned int val;
+
+	val = hdmi_read(hdmi, REG_HDMI_PHY_CTRL);
+
+	if (val & HDMI_PHY_CTRL_SW_RESET_LOW) {
+		/* pull low */
+		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
+				val & ~HDMI_PHY_CTRL_SW_RESET);
+	} else {
+		/* pull high */
+		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
+				val | HDMI_PHY_CTRL_SW_RESET);
+	}
+
+	if (val & HDMI_PHY_CTRL_SW_RESET_PLL_LOW) {
+		/* pull low */
+		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
+				val & ~HDMI_PHY_CTRL_SW_RESET_PLL);
+	} else {
+		/* pull high */
+		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
+				val | HDMI_PHY_CTRL_SW_RESET_PLL);
+	}
+
+	msleep(100);
+
+	if (val & HDMI_PHY_CTRL_SW_RESET_LOW) {
+		/* pull high */
+		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
+				val | HDMI_PHY_CTRL_SW_RESET);
+	} else {
+		/* pull low */
+		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
+				val & ~HDMI_PHY_CTRL_SW_RESET);
+	}
+
+	if (val & HDMI_PHY_CTRL_SW_RESET_PLL_LOW) {
+		/* pull high */
+		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
+				val | HDMI_PHY_CTRL_SW_RESET_PLL);
+	} else {
+		/* pull low */
+		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
+				val & ~HDMI_PHY_CTRL_SW_RESET_PLL);
+	}
+}
+
+static int gpio_config(struct hdmi *hdmi, bool on)
+{
+	const struct hdmi_platform_config *config = hdmi->config;
+	int i;
+
+	if (on) {
+		for (i = 0; i < HDMI_MAX_NUM_GPIO; i++) {
+			struct hdmi_gpio_data gpio = config->gpios[i];
+
+			if (gpio.gpiod) {
+				if (gpio.output) {
+					gpiod_direction_output(gpio.gpiod,
+							       gpio.value);
+				} else {
+					gpiod_direction_input(gpio.gpiod);
+					gpiod_set_value_cansleep(gpio.gpiod,
+								 gpio.value);
+				}
+			}
+		}
+
+		DBG("gpio on");
+	} else {
+		for (i = 0; i < HDMI_MAX_NUM_GPIO; i++) {
+			struct hdmi_gpio_data gpio = config->gpios[i];
+
+			if (!gpio.gpiod)
+				continue;
+
+			if (gpio.output) {
+				int value = gpio.value ? 0 : 1;
+
+				gpiod_set_value_cansleep(gpio.gpiod, value);
+			}
+		}
+
+		DBG("gpio off");
+	}
+
+	return 0;
+}
+
+static void enable_hpd_clocks(struct hdmi *hdmi, bool enable)
+{
+	const struct hdmi_platform_config *config = hdmi->config;
+	struct device *dev = &hdmi->pdev->dev;
+	int i, ret;
+
+	if (enable) {
+		for (i = 0; i < config->hpd_clk_cnt; i++) {
+			if (config->hpd_freq && config->hpd_freq[i]) {
+				ret = clk_set_rate(hdmi->hpd_clks[i],
+						   config->hpd_freq[i]);
+				if (ret)
+					dev_warn(dev,
+						 "failed to set clk %s (%d)\n",
+						 config->hpd_clk_names[i], ret);
+			}
+
+			ret = clk_prepare_enable(hdmi->hpd_clks[i]);
+			if (ret) {
+				DRM_DEV_ERROR(dev,
+					"failed to enable hpd clk: %s (%d)\n",
+					config->hpd_clk_names[i], ret);
+			}
+		}
+	} else {
+		for (i = config->hpd_clk_cnt - 1; i >= 0; i--)
+			clk_disable_unprepare(hdmi->hpd_clks[i]);
+	}
+}
+
+int msm_hdmi_hpd_enable(struct drm_bridge *bridge)
+{
+	struct hdmi_bridge *hdmi_bridge = to_hdmi_bridge(bridge);
+	struct hdmi *hdmi = hdmi_bridge->hdmi;
+	const struct hdmi_platform_config *config = hdmi->config;
+	struct device *dev = &hdmi->pdev->dev;
+	uint32_t hpd_ctrl;
+	int ret;
+	unsigned long flags;
+
+	ret = regulator_bulk_enable(config->hpd_reg_cnt, hdmi->hpd_regs);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "failed to enable hpd regulators: %d\n", ret);
+		goto fail;
+	}
+
+	ret = pinctrl_pm_select_default_state(dev);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "pinctrl state chg failed: %d\n", ret);
+		goto fail;
+	}
+
+	ret = gpio_config(hdmi, true);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "failed to configure GPIOs: %d\n", ret);
+		goto fail;
+	}
+
+	pm_runtime_get_sync(dev);
+	enable_hpd_clocks(hdmi, true);
+
+	msm_hdmi_set_mode(hdmi, false);
+	msm_hdmi_phy_reset(hdmi);
+	msm_hdmi_set_mode(hdmi, true);
+
+	hdmi_write(hdmi, REG_HDMI_USEC_REFTIMER, 0x0001001b);
+
+	/* enable HPD events: */
+	hdmi_write(hdmi, REG_HDMI_HPD_INT_CTRL,
+			HDMI_HPD_INT_CTRL_INT_CONNECT |
+			HDMI_HPD_INT_CTRL_INT_EN);
+
+	/* set timeout to 4.1ms (max) for hardware debounce */
+	spin_lock_irqsave(&hdmi->reg_lock, flags);
+	hpd_ctrl = hdmi_read(hdmi, REG_HDMI_HPD_CTRL);
+	hpd_ctrl |= HDMI_HPD_CTRL_TIMEOUT(0x1fff);
+
+	/* Toggle HPD circuit to trigger HPD sense */
+	hdmi_write(hdmi, REG_HDMI_HPD_CTRL,
+			~HDMI_HPD_CTRL_ENABLE & hpd_ctrl);
+	hdmi_write(hdmi, REG_HDMI_HPD_CTRL,
+			HDMI_HPD_CTRL_ENABLE | hpd_ctrl);
+	spin_unlock_irqrestore(&hdmi->reg_lock, flags);
+
+	return 0;
+
+fail:
+	return ret;
+}
+
+void msm_hdmi_hpd_disable(struct hdmi_bridge *hdmi_bridge)
+{
+	struct hdmi *hdmi = hdmi_bridge->hdmi;
+	const struct hdmi_platform_config *config = hdmi->config;
+	struct device *dev = &hdmi->pdev->dev;
+	int ret;
+
+	/* Disable HPD interrupt */
+	hdmi_write(hdmi, REG_HDMI_HPD_INT_CTRL, 0);
+
+	msm_hdmi_set_mode(hdmi, false);
+
+	enable_hpd_clocks(hdmi, false);
+	pm_runtime_put(dev);
+
+	ret = gpio_config(hdmi, false);
+	if (ret)
+		dev_warn(dev, "failed to unconfigure GPIOs: %d\n", ret);
+
+	ret = pinctrl_pm_select_sleep_state(dev);
+	if (ret)
+		dev_warn(dev, "pinctrl state chg failed: %d\n", ret);
+
+	ret = regulator_bulk_disable(config->hpd_reg_cnt, hdmi->hpd_regs);
+	if (ret)
+		dev_warn(dev, "failed to disable hpd regulator: %d\n", ret);
+}
+
+void msm_hdmi_hpd_irq(struct drm_bridge *bridge)
+{
+	struct hdmi_bridge *hdmi_bridge = to_hdmi_bridge(bridge);
+	struct hdmi *hdmi = hdmi_bridge->hdmi;
+	uint32_t hpd_int_status, hpd_int_ctrl;
+
+	/* Process HPD: */
+	hpd_int_status = hdmi_read(hdmi, REG_HDMI_HPD_INT_STATUS);
+	hpd_int_ctrl   = hdmi_read(hdmi, REG_HDMI_HPD_INT_CTRL);
+
+	if ((hpd_int_ctrl & HDMI_HPD_INT_CTRL_INT_EN) &&
+			(hpd_int_status & HDMI_HPD_INT_STATUS_INT)) {
+		bool detected = !!(hpd_int_status & HDMI_HPD_INT_STATUS_CABLE_DETECTED);
+
+		/* ack & disable (temporarily) HPD events: */
+		hdmi_write(hdmi, REG_HDMI_HPD_INT_CTRL,
+			HDMI_HPD_INT_CTRL_INT_ACK);
+
+		DBG("status=%04x, ctrl=%04x", hpd_int_status, hpd_int_ctrl);
+
+		/* detect disconnect if we are connected or visa versa: */
+		hpd_int_ctrl = HDMI_HPD_INT_CTRL_INT_EN;
+		if (!detected)
+			hpd_int_ctrl |= HDMI_HPD_INT_CTRL_INT_CONNECT;
+		hdmi_write(hdmi, REG_HDMI_HPD_INT_CTRL, hpd_int_ctrl);
+
+		queue_work(hdmi->workq, &hdmi_bridge->hpd_work);
+	}
+}
+
+static enum drm_connector_status detect_reg(struct hdmi *hdmi)
+{
+	uint32_t hpd_int_status;
+
+	pm_runtime_get_sync(&hdmi->pdev->dev);
+	enable_hpd_clocks(hdmi, true);
+
+	hpd_int_status = hdmi_read(hdmi, REG_HDMI_HPD_INT_STATUS);
+
+	enable_hpd_clocks(hdmi, false);
+	pm_runtime_put(&hdmi->pdev->dev);
+
+	return (hpd_int_status & HDMI_HPD_INT_STATUS_CABLE_DETECTED) ?
+			connector_status_connected : connector_status_disconnected;
+}
+
+#define HPD_GPIO_INDEX	2
+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 gpiod_get_value(hpd_gpio.gpiod) ?
+			connector_status_connected :
+			connector_status_disconnected;
+}
+
+enum drm_connector_status msm_hdmi_bridge_detect(
+		struct drm_bridge *bridge)
+{
+	struct hdmi_bridge *hdmi_bridge = to_hdmi_bridge(bridge);
+	struct hdmi *hdmi = hdmi_bridge->hdmi;
+	const struct hdmi_platform_config *config = hdmi->config;
+	struct hdmi_gpio_data hpd_gpio = config->gpios[HPD_GPIO_INDEX];
+	enum drm_connector_status stat_gpio, stat_reg;
+	int retry = 20;
+
+	/*
+	 * 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.gpiod)
+		return detect_reg(hdmi);
+
+	do {
+		stat_gpio = detect_gpio(hdmi);
+		stat_reg  = detect_reg(hdmi);
+
+		if (stat_gpio == stat_reg)
+			break;
+
+		mdelay(10);
+	} while (--retry);
+
+	/* the status we get from reading gpio seems to be more reliable,
+	 * so trust that one the most if we didn't manage to get hdmi and
+	 * gpio status to agree:
+	 */
+	if (stat_gpio != stat_reg) {
+		DBG("HDMI_HPD_INT_STATUS tells us: %d", stat_reg);
+		DBG("hpd gpio tells us: %d", stat_gpio);
+	}
+
+	return stat_gpio;
+}