1 files changed, 275 insertions, 0 deletions
diff --git a/drivers/media/platform/synopsys/hdmirx/snps_hdmirx_cec.c b/drivers/media/platform/synopsys/hdmirx/snps_hdmirx_cec.c
new file mode 100644
index 000000000000..8e470c0376d6
--- /dev/null
+++ b/drivers/media/platform/synopsys/hdmirx/snps_hdmirx_cec.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 Rockchip Electronics Co. Ltd.
+ *
+ * Author: Shunqing Chen <csq@rock-chips.com>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <media/cec.h>
+
+#include "snps_hdmirx.h"
+#include "snps_hdmirx_cec.h"
+
+static void hdmirx_cec_write(struct hdmirx_cec *cec, int reg, u32 val)
+{
+	cec->ops->write(cec->hdmirx, reg, val);
+}
+
+static u32 hdmirx_cec_read(struct hdmirx_cec *cec, int reg)
+{
+	return cec->ops->read(cec->hdmirx, reg);
+}
+
+static void hdmirx_cec_update_bits(struct hdmirx_cec *cec, int reg, u32 mask,
+				   u32 data)
+{
+	u32 val = hdmirx_cec_read(cec, reg) & ~mask;
+
+	val |= (data & mask);
+	hdmirx_cec_write(cec, reg, val);
+}
+
+static int hdmirx_cec_log_addr(struct cec_adapter *adap, u8 logical_addr)
+{
+	struct hdmirx_cec *cec = cec_get_drvdata(adap);
+
+	if (logical_addr == CEC_LOG_ADDR_INVALID)
+		cec->addresses = 0;
+	else
+		cec->addresses |= BIT(logical_addr) | BIT(15);
+
+	hdmirx_cec_write(cec, CEC_ADDR, cec->addresses);
+
+	return 0;
+}
+
+/* signal_free_time is handled by the Synopsys Designware
+ * HDMIRX Controller hardware.
+ */
+static int hdmirx_cec_transmit(struct cec_adapter *adap, u8 attempts,
+			       u32 signal_free_time, struct cec_msg *msg)
+{
+	struct hdmirx_cec *cec = cec_get_drvdata(adap);
+	u32 data[4] = {0};
+	int i, data_len, msg_len;
+
+	msg_len = msg->len;
+
+	hdmirx_cec_write(cec, CEC_TX_COUNT, msg_len - 1);
+	for (i = 0; i < msg_len; i++)
+		data[i / 4] |= msg->msg[i] << (i % 4) * 8;
+
+	data_len = DIV_ROUND_UP(msg_len, 4);
+
+	for (i = 0; i < data_len; i++)
+		hdmirx_cec_write(cec, CEC_TX_DATA3_0 + i * 4, data[i]);
+
+	hdmirx_cec_write(cec, CEC_TX_CONTROL, 0x1);
+
+	return 0;
+}
+
+static irqreturn_t hdmirx_cec_hardirq(int irq, void *data)
+{
+	struct cec_adapter *adap = data;
+	struct hdmirx_cec *cec = cec_get_drvdata(adap);
+	u32 stat = hdmirx_cec_read(cec, CEC_INT_STATUS);
+	irqreturn_t ret = IRQ_HANDLED;
+	u32 val;
+
+	if (!stat)
+		return IRQ_NONE;
+
+	hdmirx_cec_write(cec, CEC_INT_CLEAR, stat);
+
+	if (stat & CECTX_LINE_ERR) {
+		cec->tx_status = CEC_TX_STATUS_ERROR;
+		cec->tx_done = true;
+		ret = IRQ_WAKE_THREAD;
+	} else if (stat & CECTX_DONE) {
+		cec->tx_status = CEC_TX_STATUS_OK;
+		cec->tx_done = true;
+		ret = IRQ_WAKE_THREAD;
+	} else if (stat & CECTX_NACK) {
+		cec->tx_status = CEC_TX_STATUS_NACK;
+		cec->tx_done = true;
+		ret = IRQ_WAKE_THREAD;
+	} else if (stat & CECTX_ARBLOST) {
+		cec->tx_status = CEC_TX_STATUS_ARB_LOST;
+		cec->tx_done = true;
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	if (stat & CECRX_EOM) {
+		unsigned int len, i;
+
+		val = hdmirx_cec_read(cec, CEC_RX_COUNT_STATUS);
+		/* rxbuffer locked status */
+		if ((val & 0x80))
+			return ret;
+
+		len = (val & 0xf) + 1;
+		if (len > sizeof(cec->rx_msg.msg))
+			len = sizeof(cec->rx_msg.msg);
+
+		for (i = 0; i < len; i++) {
+			if (!(i % 4))
+				val = hdmirx_cec_read(cec, CEC_RX_DATA3_0 + i / 4 * 4);
+			cec->rx_msg.msg[i] = (val >> ((i % 4) * 8)) & 0xff;
+		}
+
+		cec->rx_msg.len = len;
+		smp_wmb(); /* receive RX msg */
+		cec->rx_done = true;
+		hdmirx_cec_write(cec, CEC_LOCK_CONTROL, 0x1);
+
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	return ret;
+}
+
+static irqreturn_t hdmirx_cec_thread(int irq, void *data)
+{
+	struct cec_adapter *adap = data;
+	struct hdmirx_cec *cec = cec_get_drvdata(adap);
+
+	if (cec->tx_done) {
+		cec->tx_done = false;
+		cec_transmit_attempt_done(adap, cec->tx_status);
+	}
+	if (cec->rx_done) {
+		cec->rx_done = false;
+		smp_rmb(); /* RX msg has been received */
+		cec_received_msg(adap, &cec->rx_msg);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int hdmirx_cec_enable(struct cec_adapter *adap, bool enable)
+{
+	struct hdmirx_cec *cec = cec_get_drvdata(adap);
+
+	if (!enable) {
+		hdmirx_cec_write(cec, CEC_INT_MASK_N, 0);
+		hdmirx_cec_write(cec, CEC_INT_CLEAR, 0);
+		if (cec->ops->disable)
+			cec->ops->disable(cec->hdmirx);
+	} else {
+		unsigned int irqs;
+
+		hdmirx_cec_log_addr(cec->adap, CEC_LOG_ADDR_INVALID);
+		if (cec->ops->enable)
+			cec->ops->enable(cec->hdmirx);
+		hdmirx_cec_update_bits(cec, GLOBAL_SWENABLE, CEC_ENABLE, CEC_ENABLE);
+
+		irqs = CECTX_LINE_ERR | CECTX_NACK | CECRX_EOM | CECTX_DONE;
+		hdmirx_cec_write(cec, CEC_INT_MASK_N, irqs);
+	}
+
+	return 0;
+}
+
+static const struct cec_adap_ops hdmirx_cec_ops = {
+	.adap_enable = hdmirx_cec_enable,
+	.adap_log_addr = hdmirx_cec_log_addr,
+	.adap_transmit = hdmirx_cec_transmit,
+};
+
+static void hdmirx_cec_del(void *data)
+{
+	struct hdmirx_cec *cec = data;
+
+	cec_delete_adapter(cec->adap);
+}
+
+struct hdmirx_cec *snps_hdmirx_cec_register(struct hdmirx_cec_data *data)
+{
+	struct hdmirx_cec *cec;
+	unsigned int irqs;
+	int ret;
+
+	/*
+	 * Our device is just a convenience - we want to link to the real
+	 * hardware device here, so that userspace can see the association
+	 * between the HDMI hardware and its associated CEC chardev.
+	 */
+	cec = devm_kzalloc(data->dev, sizeof(*cec), GFP_KERNEL);
+	if (!cec)
+		return ERR_PTR(-ENOMEM);
+
+	cec->dev = data->dev;
+	cec->irq = data->irq;
+	cec->ops = data->ops;
+	cec->hdmirx = data->hdmirx;
+
+	hdmirx_cec_update_bits(cec, GLOBAL_SWENABLE, CEC_ENABLE, CEC_ENABLE);
+	hdmirx_cec_update_bits(cec, CEC_CONFIG, RX_AUTO_DRIVE_ACKNOWLEDGE,
+			       RX_AUTO_DRIVE_ACKNOWLEDGE);
+
+	hdmirx_cec_write(cec, CEC_TX_COUNT, 0);
+	hdmirx_cec_write(cec, CEC_INT_MASK_N, 0);
+	hdmirx_cec_write(cec, CEC_INT_CLEAR, ~0);
+
+	cec->adap = cec_allocate_adapter(&hdmirx_cec_ops, cec, "snps-hdmirx",
+					 CEC_CAP_DEFAULTS | CEC_CAP_MONITOR_ALL,
+					 CEC_MAX_LOG_ADDRS);
+	if (IS_ERR(cec->adap)) {
+		dev_err(cec->dev, "cec adapter allocation failed\n");
+		return ERR_CAST(cec->adap);
+	}
+
+	/* override the module pointer */
+	cec->adap->owner = THIS_MODULE;
+
+	ret = devm_add_action(cec->dev, hdmirx_cec_del, cec);
+	if (ret) {
+		cec_delete_adapter(cec->adap);
+		return ERR_PTR(ret);
+	}
+
+	irq_set_status_flags(cec->irq, IRQ_NOAUTOEN);
+
+	ret = devm_request_threaded_irq(cec->dev, cec->irq,
+					hdmirx_cec_hardirq,
+					hdmirx_cec_thread, IRQF_ONESHOT,
+					"rk_hdmirx_cec", cec->adap);
+	if (ret) {
+		dev_err(cec->dev, "cec irq request failed\n");
+		return ERR_PTR(ret);
+	}
+
+	ret = cec_register_adapter(cec->adap, cec->dev);
+	if (ret < 0) {
+		dev_err(cec->dev, "cec adapter registration failed\n");
+		return ERR_PTR(ret);
+	}
+
+	irqs = CECTX_LINE_ERR | CECTX_NACK | CECRX_EOM | CECTX_DONE;
+	hdmirx_cec_write(cec, CEC_INT_MASK_N, irqs);
+
+	/*
+	 * CEC documentation says we must not call cec_delete_adapter
+	 * after a successful call to cec_register_adapter().
+	 */
+	devm_remove_action(cec->dev, hdmirx_cec_del, cec);
+
+	enable_irq(cec->irq);
+
+	return cec;
+}
+
+void snps_hdmirx_cec_unregister(struct hdmirx_cec *cec)
+{
+	disable_irq(cec->irq);
+
+	cec_unregister_adapter(cec->adap);
+}