1 files changed, 483 insertions, 0 deletions
diff --git a/drivers/media/cec/platform/tegra/tegra_cec.c b/drivers/media/cec/platform/tegra/tegra_cec.c
new file mode 100644
index 000000000..5e907395c
--- /dev/null
+++ b/drivers/media/cec/platform/tegra/tegra_cec.c
@@ -0,0 +1,483 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Tegra CEC implementation
+ *
+ * The original 3.10 CEC driver using a custom API:
+ *
+ * Copyright (c) 2012-2015, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Conversion to the CEC framework and to the mainline kernel:
+ *
+ * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/pm.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/clk/tegra.h>
+
+#include <media/cec-notifier.h>
+
+#include "tegra_cec.h"
+
+#define TEGRA_CEC_NAME "tegra-cec"
+
+struct tegra_cec {
+	struct cec_adapter	*adap;
+	struct device		*dev;
+	struct clk		*clk;
+	void __iomem		*cec_base;
+	struct cec_notifier	*notifier;
+	int			tegra_cec_irq;
+	bool			rx_done;
+	bool			tx_done;
+	int			tx_status;
+	u8			rx_buf[CEC_MAX_MSG_SIZE];
+	u8			rx_buf_cnt;
+	u32			tx_buf[CEC_MAX_MSG_SIZE];
+	u8			tx_buf_cur;
+	u8			tx_buf_cnt;
+};
+
+static inline u32 cec_read(struct tegra_cec *cec, u32 reg)
+{
+	return readl(cec->cec_base + reg);
+}
+
+static inline void cec_write(struct tegra_cec *cec, u32 reg, u32 val)
+{
+	writel(val, cec->cec_base + reg);
+}
+
+static void tegra_cec_error_recovery(struct tegra_cec *cec)
+{
+	u32 hw_ctrl;
+
+	hw_ctrl = cec_read(cec, TEGRA_CEC_HW_CONTROL);
+	cec_write(cec, TEGRA_CEC_HW_CONTROL, 0);
+	cec_write(cec, TEGRA_CEC_INT_STAT, 0xffffffff);
+	cec_write(cec, TEGRA_CEC_HW_CONTROL, hw_ctrl);
+}
+
+static irqreturn_t tegra_cec_irq_thread_handler(int irq, void *data)
+{
+	struct device *dev = data;
+	struct tegra_cec *cec = dev_get_drvdata(dev);
+
+	if (cec->tx_done) {
+		cec_transmit_attempt_done(cec->adap, cec->tx_status);
+		cec->tx_done = false;
+	}
+	if (cec->rx_done) {
+		struct cec_msg msg = {};
+
+		msg.len = cec->rx_buf_cnt;
+		memcpy(msg.msg, cec->rx_buf, msg.len);
+		cec_received_msg(cec->adap, &msg);
+		cec->rx_done = false;
+		cec->rx_buf_cnt = 0;
+	}
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t tegra_cec_irq_handler(int irq, void *data)
+{
+	struct device *dev = data;
+	struct tegra_cec *cec = dev_get_drvdata(dev);
+	u32 status, mask;
+
+	status = cec_read(cec, TEGRA_CEC_INT_STAT);
+	mask = cec_read(cec, TEGRA_CEC_INT_MASK);
+
+	status &= mask;
+
+	if (!status)
+		return IRQ_HANDLED;
+
+	if (status & TEGRA_CEC_INT_STAT_TX_REGISTER_UNDERRUN) {
+		dev_err(dev, "TX underrun, interrupt timing issue!\n");
+
+		tegra_cec_error_recovery(cec);
+		cec_write(cec, TEGRA_CEC_INT_MASK,
+			  mask & ~TEGRA_CEC_INT_MASK_TX_REGISTER_EMPTY);
+
+		cec->tx_done = true;
+		cec->tx_status = CEC_TX_STATUS_ERROR;
+		return IRQ_WAKE_THREAD;
+	}
+
+	if ((status & TEGRA_CEC_INT_STAT_TX_ARBITRATION_FAILED) ||
+		   (status & TEGRA_CEC_INT_STAT_TX_BUS_ANOMALY_DETECTED)) {
+		tegra_cec_error_recovery(cec);
+		cec_write(cec, TEGRA_CEC_INT_MASK,
+			  mask & ~TEGRA_CEC_INT_MASK_TX_REGISTER_EMPTY);
+
+		cec->tx_done = true;
+		if (status & TEGRA_CEC_INT_STAT_TX_BUS_ANOMALY_DETECTED)
+			cec->tx_status = CEC_TX_STATUS_LOW_DRIVE;
+		else
+			cec->tx_status = CEC_TX_STATUS_ARB_LOST;
+		return IRQ_WAKE_THREAD;
+	}
+
+	if (status & TEGRA_CEC_INT_STAT_TX_FRAME_TRANSMITTED) {
+		cec_write(cec, TEGRA_CEC_INT_STAT,
+			  TEGRA_CEC_INT_STAT_TX_FRAME_TRANSMITTED);
+
+		if (status & TEGRA_CEC_INT_STAT_TX_FRAME_OR_BLOCK_NAKD) {
+			tegra_cec_error_recovery(cec);
+
+			cec->tx_done = true;
+			cec->tx_status = CEC_TX_STATUS_NACK;
+		} else {
+			cec->tx_done = true;
+			cec->tx_status = CEC_TX_STATUS_OK;
+		}
+		return IRQ_WAKE_THREAD;
+	}
+
+	if (status & TEGRA_CEC_INT_STAT_TX_FRAME_OR_BLOCK_NAKD)
+		dev_warn(dev, "TX NAKed on the fly!\n");
+
+	if (status & TEGRA_CEC_INT_STAT_TX_REGISTER_EMPTY) {
+		if (cec->tx_buf_cur == cec->tx_buf_cnt) {
+			cec_write(cec, TEGRA_CEC_INT_MASK,
+				  mask & ~TEGRA_CEC_INT_MASK_TX_REGISTER_EMPTY);
+		} else {
+			cec_write(cec, TEGRA_CEC_TX_REGISTER,
+				  cec->tx_buf[cec->tx_buf_cur++]);
+			cec_write(cec, TEGRA_CEC_INT_STAT,
+				  TEGRA_CEC_INT_STAT_TX_REGISTER_EMPTY);
+		}
+	}
+
+	if (status & TEGRA_CEC_INT_STAT_RX_START_BIT_DETECTED) {
+		cec_write(cec, TEGRA_CEC_INT_STAT,
+			  TEGRA_CEC_INT_STAT_RX_START_BIT_DETECTED);
+		cec->rx_done = false;
+		cec->rx_buf_cnt = 0;
+	}
+	if (status & TEGRA_CEC_INT_STAT_RX_REGISTER_FULL) {
+		u32 v;
+
+		cec_write(cec, TEGRA_CEC_INT_STAT,
+			  TEGRA_CEC_INT_STAT_RX_REGISTER_FULL);
+		v = cec_read(cec, TEGRA_CEC_RX_REGISTER);
+		if (cec->rx_buf_cnt < CEC_MAX_MSG_SIZE)
+			cec->rx_buf[cec->rx_buf_cnt++] = v & 0xff;
+		if (v & TEGRA_CEC_RX_REGISTER_EOM) {
+			cec->rx_done = true;
+			return IRQ_WAKE_THREAD;
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int tegra_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct tegra_cec *cec = adap->priv;
+
+	cec->rx_buf_cnt = 0;
+	cec->tx_buf_cnt = 0;
+	cec->tx_buf_cur = 0;
+
+	cec_write(cec, TEGRA_CEC_HW_CONTROL, 0);
+	cec_write(cec, TEGRA_CEC_INT_MASK, 0);
+	cec_write(cec, TEGRA_CEC_INT_STAT, 0xffffffff);
+	cec_write(cec, TEGRA_CEC_SW_CONTROL, 0);
+
+	if (!enable)
+		return 0;
+
+	cec_write(cec, TEGRA_CEC_INPUT_FILTER, (1U << 31) | 0x20);
+
+	cec_write(cec, TEGRA_CEC_RX_TIMING_0,
+		  (0x7a << TEGRA_CEC_RX_TIM0_START_BIT_MAX_LO_TIME_SHIFT) |
+		  (0x6d << TEGRA_CEC_RX_TIM0_START_BIT_MIN_LO_TIME_SHIFT) |
+		  (0x93 << TEGRA_CEC_RX_TIM0_START_BIT_MAX_DURATION_SHIFT) |
+		  (0x86 << TEGRA_CEC_RX_TIM0_START_BIT_MIN_DURATION_SHIFT));
+
+	cec_write(cec, TEGRA_CEC_RX_TIMING_1,
+		  (0x35 << TEGRA_CEC_RX_TIM1_DATA_BIT_MAX_LO_TIME_SHIFT) |
+		  (0x21 << TEGRA_CEC_RX_TIM1_DATA_BIT_SAMPLE_TIME_SHIFT) |
+		  (0x56 << TEGRA_CEC_RX_TIM1_DATA_BIT_MAX_DURATION_SHIFT) |
+		  (0x40 << TEGRA_CEC_RX_TIM1_DATA_BIT_MIN_DURATION_SHIFT));
+
+	cec_write(cec, TEGRA_CEC_RX_TIMING_2,
+		  (0x50 << TEGRA_CEC_RX_TIM2_END_OF_BLOCK_TIME_SHIFT));
+
+	cec_write(cec, TEGRA_CEC_TX_TIMING_0,
+		  (0x74 << TEGRA_CEC_TX_TIM0_START_BIT_LO_TIME_SHIFT) |
+		  (0x8d << TEGRA_CEC_TX_TIM0_START_BIT_DURATION_SHIFT) |
+		  (0x08 << TEGRA_CEC_TX_TIM0_BUS_XITION_TIME_SHIFT) |
+		  (0x71 << TEGRA_CEC_TX_TIM0_BUS_ERROR_LO_TIME_SHIFT));
+
+	cec_write(cec, TEGRA_CEC_TX_TIMING_1,
+		  (0x2f << TEGRA_CEC_TX_TIM1_LO_DATA_BIT_LO_TIME_SHIFT) |
+		  (0x13 << TEGRA_CEC_TX_TIM1_HI_DATA_BIT_LO_TIME_SHIFT) |
+		  (0x4b << TEGRA_CEC_TX_TIM1_DATA_BIT_DURATION_SHIFT) |
+		  (0x21 << TEGRA_CEC_TX_TIM1_ACK_NAK_BIT_SAMPLE_TIME_SHIFT));
+
+	cec_write(cec, TEGRA_CEC_TX_TIMING_2,
+		  (0x07 << TEGRA_CEC_TX_TIM2_BUS_IDLE_TIME_ADDITIONAL_FRAME_SHIFT) |
+		  (0x05 << TEGRA_CEC_TX_TIM2_BUS_IDLE_TIME_NEW_FRAME_SHIFT) |
+		  (0x03 << TEGRA_CEC_TX_TIM2_BUS_IDLE_TIME_RETRY_FRAME_SHIFT));
+
+	cec_write(cec, TEGRA_CEC_INT_MASK,
+		  TEGRA_CEC_INT_MASK_TX_REGISTER_UNDERRUN |
+		  TEGRA_CEC_INT_MASK_TX_FRAME_OR_BLOCK_NAKD |
+		  TEGRA_CEC_INT_MASK_TX_ARBITRATION_FAILED |
+		  TEGRA_CEC_INT_MASK_TX_BUS_ANOMALY_DETECTED |
+		  TEGRA_CEC_INT_MASK_TX_FRAME_TRANSMITTED |
+		  TEGRA_CEC_INT_MASK_RX_REGISTER_FULL |
+		  TEGRA_CEC_INT_MASK_RX_START_BIT_DETECTED);
+
+	cec_write(cec, TEGRA_CEC_HW_CONTROL, TEGRA_CEC_HWCTRL_TX_RX_MODE);
+	return 0;
+}
+
+static int tegra_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
+{
+	struct tegra_cec *cec = adap->priv;
+	u32 state = cec_read(cec, TEGRA_CEC_HW_CONTROL);
+
+	if (logical_addr == CEC_LOG_ADDR_INVALID)
+		state &= ~TEGRA_CEC_HWCTRL_RX_LADDR_MASK;
+	else
+		state |= TEGRA_CEC_HWCTRL_RX_LADDR((1 << logical_addr));
+
+	cec_write(cec, TEGRA_CEC_HW_CONTROL, state);
+	return 0;
+}
+
+static int tegra_cec_adap_monitor_all_enable(struct cec_adapter *adap,
+					     bool enable)
+{
+	struct tegra_cec *cec = adap->priv;
+	u32 reg = cec_read(cec, TEGRA_CEC_HW_CONTROL);
+
+	if (enable)
+		reg |= TEGRA_CEC_HWCTRL_RX_SNOOP;
+	else
+		reg &= ~TEGRA_CEC_HWCTRL_RX_SNOOP;
+	cec_write(cec, TEGRA_CEC_HW_CONTROL, reg);
+	return 0;
+}
+
+static int tegra_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
+				   u32 signal_free_time_ms, struct cec_msg *msg)
+{
+	bool retry_xfer = signal_free_time_ms == CEC_SIGNAL_FREE_TIME_RETRY;
+	struct tegra_cec *cec = adap->priv;
+	unsigned int i;
+	u32 mode = 0;
+	u32 mask;
+
+	if (cec_msg_is_broadcast(msg))
+		mode = TEGRA_CEC_TX_REG_BCAST;
+
+	cec->tx_buf_cur = 0;
+	cec->tx_buf_cnt = msg->len;
+
+	for (i = 0; i < msg->len; i++) {
+		cec->tx_buf[i] = mode | msg->msg[i];
+		if (i == 0)
+			cec->tx_buf[i] |= TEGRA_CEC_TX_REG_START_BIT;
+		if (i == msg->len - 1)
+			cec->tx_buf[i] |= TEGRA_CEC_TX_REG_EOM;
+		if (i == 0 && retry_xfer)
+			cec->tx_buf[i] |= TEGRA_CEC_TX_REG_RETRY;
+	}
+
+	mask = cec_read(cec, TEGRA_CEC_INT_MASK);
+	cec_write(cec, TEGRA_CEC_INT_MASK,
+		  mask | TEGRA_CEC_INT_MASK_TX_REGISTER_EMPTY);
+
+	return 0;
+}
+
+static const struct cec_adap_ops tegra_cec_ops = {
+	.adap_enable = tegra_cec_adap_enable,
+	.adap_log_addr = tegra_cec_adap_log_addr,
+	.adap_transmit = tegra_cec_adap_transmit,
+	.adap_monitor_all_enable = tegra_cec_adap_monitor_all_enable,
+};
+
+static int tegra_cec_probe(struct platform_device *pdev)
+{
+	struct device *hdmi_dev;
+	struct tegra_cec *cec;
+	struct resource *res;
+	int ret = 0;
+
+	hdmi_dev = cec_notifier_parse_hdmi_phandle(&pdev->dev);
+
+	if (IS_ERR(hdmi_dev))
+		return PTR_ERR(hdmi_dev);
+
+	cec = devm_kzalloc(&pdev->dev, sizeof(struct tegra_cec), GFP_KERNEL);
+
+	if (!cec)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	if (!res) {
+		dev_err(&pdev->dev,
+			"Unable to allocate resources for device\n");
+		return -EBUSY;
+	}
+
+	if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
+		pdev->name)) {
+		dev_err(&pdev->dev,
+			"Unable to request mem region for device\n");
+		return -EBUSY;
+	}
+
+	cec->tegra_cec_irq = platform_get_irq(pdev, 0);
+
+	if (cec->tegra_cec_irq <= 0)
+		return -EBUSY;
+
+	cec->cec_base = devm_ioremap(&pdev->dev, res->start,
+					     resource_size(res));
+
+	if (!cec->cec_base) {
+		dev_err(&pdev->dev, "Unable to grab IOs for device\n");
+		return -EBUSY;
+	}
+
+	cec->clk = devm_clk_get(&pdev->dev, "cec");
+
+	if (IS_ERR_OR_NULL(cec->clk)) {
+		dev_err(&pdev->dev, "Can't get clock for CEC\n");
+		return -ENOENT;
+	}
+
+	ret = clk_prepare_enable(cec->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to prepare clock for CEC\n");
+		return ret;
+	}
+
+	/* set context info. */
+	cec->dev = &pdev->dev;
+
+	platform_set_drvdata(pdev, cec);
+
+	ret = devm_request_threaded_irq(&pdev->dev, cec->tegra_cec_irq,
+		tegra_cec_irq_handler, tegra_cec_irq_thread_handler,
+		0, "cec_irq", &pdev->dev);
+
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Unable to request interrupt for device\n");
+		goto err_clk;
+	}
+
+	cec->adap = cec_allocate_adapter(&tegra_cec_ops, cec, TEGRA_CEC_NAME,
+			CEC_CAP_DEFAULTS | CEC_CAP_MONITOR_ALL |
+			CEC_CAP_CONNECTOR_INFO,
+			CEC_MAX_LOG_ADDRS);
+	if (IS_ERR(cec->adap)) {
+		ret = -ENOMEM;
+		dev_err(&pdev->dev, "Couldn't create cec adapter\n");
+		goto err_clk;
+	}
+
+	cec->notifier = cec_notifier_cec_adap_register(hdmi_dev, NULL,
+						       cec->adap);
+	if (!cec->notifier) {
+		ret = -ENOMEM;
+		goto err_adapter;
+	}
+
+	ret = cec_register_adapter(cec->adap, &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Couldn't register device\n");
+		goto err_notifier;
+	}
+
+	return 0;
+
+err_notifier:
+	cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
+err_adapter:
+	cec_delete_adapter(cec->adap);
+err_clk:
+	clk_disable_unprepare(cec->clk);
+	return ret;
+}
+
+static int tegra_cec_remove(struct platform_device *pdev)
+{
+	struct tegra_cec *cec = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(cec->clk);
+
+	cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
+	cec_unregister_adapter(cec->adap);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int tegra_cec_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct tegra_cec *cec = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(cec->clk);
+
+	dev_notice(&pdev->dev, "suspended\n");
+	return 0;
+}
+
+static int tegra_cec_resume(struct platform_device *pdev)
+{
+	struct tegra_cec *cec = platform_get_drvdata(pdev);
+
+	dev_notice(&pdev->dev, "Resuming\n");
+
+	return clk_prepare_enable(cec->clk);
+}
+#endif
+
+static const struct of_device_id tegra_cec_of_match[] = {
+	{ .compatible = "nvidia,tegra114-cec", },
+	{ .compatible = "nvidia,tegra124-cec", },
+	{ .compatible = "nvidia,tegra210-cec", },
+	{},
+};
+
+static struct platform_driver tegra_cec_driver = {
+	.driver = {
+		.name = TEGRA_CEC_NAME,
+		.of_match_table = of_match_ptr(tegra_cec_of_match),
+	},
+	.probe = tegra_cec_probe,
+	.remove = tegra_cec_remove,
+
+#ifdef CONFIG_PM
+	.suspend = tegra_cec_suspend,
+	.resume = tegra_cec_resume,
+#endif
+};
+
+module_platform_driver(tegra_cec_driver);
+
+MODULE_DESCRIPTION("Tegra HDMI CEC driver");
+MODULE_AUTHOR("NVIDIA CORPORATION");
+MODULE_AUTHOR("Cisco Systems, Inc. and/or its affiliates");
+MODULE_LICENSE("GPL v2");