[media] vivid: add CEC emulation

The vivid driver has been extended to provide CEC adapters for the HDMI
input and HDMI outputs in order to test CEC applications.

This CEC emulation is faithful to the CEC timings (i.e., it all at a
snail's pace).

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 255 insertions, 0 deletions

diff --git a/drivers/media/platform/vivid/vivid-cec.c b/drivers/media/platform/vivid/vivid-cec.c
new file mode 100644
index 000000000000..b5714fae905d
--- /dev/null
+++ b/drivers/media/platform/vivid/vivid-cec.c
@@ -0,0 +1,255 @@
+/*
+ * vivid-cec.c - A Virtual Video Test Driver, cec emulation
+ *
+ * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <media/cec.h>
+
+#include "vivid-core.h"
+#include "vivid-cec.h"
+
+void vivid_cec_bus_free_work(struct vivid_dev *dev)
+{
+	spin_lock(&dev->cec_slock);
+	while (!list_empty(&dev->cec_work_list)) {
+		struct vivid_cec_work *cw =
+			list_first_entry(&dev->cec_work_list,
+					 struct vivid_cec_work, list);
+
+		spin_unlock(&dev->cec_slock);
+		cancel_delayed_work_sync(&cw->work);
+		spin_lock(&dev->cec_slock);
+		list_del(&cw->list);
+		cec_transmit_done(cw->adap, CEC_TX_STATUS_LOW_DRIVE, 0, 0, 1, 0);
+		kfree(cw);
+	}
+	spin_unlock(&dev->cec_slock);
+}
+
+static struct cec_adapter *vivid_cec_find_dest_adap(struct vivid_dev *dev,
+						    struct cec_adapter *adap,
+						    u8 dest)
+{
+	unsigned int i;
+
+	if (dest >= 0xf)
+		return NULL;
+
+	if (adap != dev->cec_rx_adap && dev->cec_rx_adap &&
+	    dev->cec_rx_adap->is_configured &&
+	    cec_has_log_addr(dev->cec_rx_adap, dest))
+		return dev->cec_rx_adap;
+
+	for (i = 0; i < MAX_OUTPUTS && dev->cec_tx_adap[i]; i++) {
+		if (adap == dev->cec_tx_adap[i])
+			continue;
+		if (!dev->cec_tx_adap[i]->is_configured)
+			continue;
+		if (cec_has_log_addr(dev->cec_tx_adap[i], dest))
+			return dev->cec_tx_adap[i];
+	}
+	return NULL;
+}
+
+static void vivid_cec_xfer_done_worker(struct work_struct *work)
+{
+	struct vivid_cec_work *cw =
+		container_of(work, struct vivid_cec_work, work.work);
+	struct vivid_dev *dev = cw->dev;
+	struct cec_adapter *adap = cw->adap;
+	bool is_poll = cw->msg.len == 1;
+	u8 dest = cec_msg_destination(&cw->msg);
+	struct cec_adapter *dest_adap = NULL;
+	bool valid_dest;
+	unsigned int i;
+
+	valid_dest = cec_msg_is_broadcast(&cw->msg);
+	if (!valid_dest) {
+		dest_adap = vivid_cec_find_dest_adap(dev, adap, dest);
+		if (dest_adap)
+			valid_dest = true;
+	}
+	cw->tx_status = valid_dest ? CEC_TX_STATUS_OK : CEC_TX_STATUS_NACK;
+	spin_lock(&dev->cec_slock);
+	dev->cec_xfer_time_jiffies = 0;
+	dev->cec_xfer_start_jiffies = 0;
+	list_del(&cw->list);
+	spin_unlock(&dev->cec_slock);
+	cec_transmit_done(cw->adap, cw->tx_status, 0, valid_dest ? 0 : 1, 0, 0);
+
+	if (!is_poll && dest_adap) {
+		/* Directed message */
+		cec_received_msg(dest_adap, &cw->msg);
+	} else if (!is_poll && valid_dest) {
+		/* Broadcast message */
+		if (adap != dev->cec_rx_adap &&
+		    dev->cec_rx_adap->log_addrs.log_addr_mask)
+			cec_received_msg(dev->cec_rx_adap, &cw->msg);
+		for (i = 0; i < MAX_OUTPUTS && dev->cec_tx_adap[i]; i++) {
+			if (adap == dev->cec_tx_adap[i] ||
+			    !dev->cec_tx_adap[i]->log_addrs.log_addr_mask)
+				continue;
+			cec_received_msg(dev->cec_tx_adap[i], &cw->msg);
+		}
+	}
+	kfree(cw);
+}
+
+static void vivid_cec_xfer_try_worker(struct work_struct *work)
+{
+	struct vivid_cec_work *cw =
+		container_of(work, struct vivid_cec_work, work.work);
+	struct vivid_dev *dev = cw->dev;
+
+	spin_lock(&dev->cec_slock);
+	if (dev->cec_xfer_time_jiffies) {
+		list_del(&cw->list);
+		spin_unlock(&dev->cec_slock);
+		cec_transmit_done(cw->adap, CEC_TX_STATUS_ARB_LOST, 1, 0, 0, 0);
+		kfree(cw);
+	} else {
+		INIT_DELAYED_WORK(&cw->work, vivid_cec_xfer_done_worker);
+		dev->cec_xfer_start_jiffies = jiffies;
+		dev->cec_xfer_time_jiffies = usecs_to_jiffies(cw->usecs);
+		spin_unlock(&dev->cec_slock);
+		schedule_delayed_work(&cw->work, dev->cec_xfer_time_jiffies);
+	}
+}
+
+static int vivid_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	return 0;
+}
+
+static int vivid_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
+{
+	return 0;
+}
+
+/*
+ * One data bit takes 2400 us, each byte needs 10 bits so that's 24000 us
+ * per byte.
+ */
+#define USECS_PER_BYTE 24000
+
+static int vivid_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
+				   u32 signal_free_time, struct cec_msg *msg)
+{
+	struct vivid_dev *dev = adap->priv;
+	struct vivid_cec_work *cw = kzalloc(sizeof(*cw), GFP_KERNEL);
+	long delta_jiffies = 0;
+
+	if (cw == NULL)
+		return -ENOMEM;
+	cw->dev = dev;
+	cw->adap = adap;
+	cw->usecs = CEC_FREE_TIME_TO_USEC(signal_free_time) +
+		    msg->len * USECS_PER_BYTE;
+	cw->msg = *msg;
+
+	spin_lock(&dev->cec_slock);
+	list_add(&cw->list, &dev->cec_work_list);
+	if (dev->cec_xfer_time_jiffies == 0) {
+		INIT_DELAYED_WORK(&cw->work, vivid_cec_xfer_done_worker);
+		dev->cec_xfer_start_jiffies = jiffies;
+		dev->cec_xfer_time_jiffies = usecs_to_jiffies(cw->usecs);
+		delta_jiffies = dev->cec_xfer_time_jiffies;
+	} else {
+		INIT_DELAYED_WORK(&cw->work, vivid_cec_xfer_try_worker);
+		delta_jiffies = dev->cec_xfer_start_jiffies +
+			dev->cec_xfer_time_jiffies - jiffies;
+	}
+	spin_unlock(&dev->cec_slock);
+	schedule_delayed_work(&cw->work, delta_jiffies < 0 ? 0 : delta_jiffies);
+	return 0;
+}
+
+static int vivid_received(struct cec_adapter *adap, struct cec_msg *msg)
+{
+	struct vivid_dev *dev = adap->priv;
+	struct cec_msg reply;
+	u8 dest = cec_msg_destination(msg);
+	u16 pa;
+	u8 disp_ctl;
+	char osd[14];
+
+	if (cec_msg_is_broadcast(msg))
+		dest = adap->log_addrs.log_addr[0];
+	cec_msg_init(&reply, dest, cec_msg_initiator(msg));
+
+	switch (cec_msg_opcode(msg)) {
+	case CEC_MSG_SET_STREAM_PATH:
+		if (cec_is_sink(adap))
+			return -ENOMSG;
+		cec_ops_set_stream_path(msg, &pa);
+		if (pa != adap->phys_addr)
+			return -ENOMSG;
+		cec_msg_active_source(&reply, adap->phys_addr);
+		cec_transmit_msg(adap, &reply, false);
+		break;
+	case CEC_MSG_SET_OSD_STRING:
+		if (!cec_is_sink(adap))
+			return -ENOMSG;
+		cec_ops_set_osd_string(msg, &disp_ctl, osd);
+		switch (disp_ctl) {
+		case CEC_OP_DISP_CTL_DEFAULT:
+			strcpy(dev->osd, osd);
+			dev->osd_jiffies = jiffies;
+			break;
+		case CEC_OP_DISP_CTL_UNTIL_CLEARED:
+			strcpy(dev->osd, osd);
+			dev->osd_jiffies = 0;
+			break;
+		case CEC_OP_DISP_CTL_CLEAR:
+			dev->osd[0] = 0;
+			dev->osd_jiffies = 0;
+			break;
+		default:
+			cec_msg_feature_abort(&reply, cec_msg_opcode(msg),
+					      CEC_OP_ABORT_INVALID_OP);
+			cec_transmit_msg(adap, &reply, false);
+			break;
+		}
+		break;
+	default:
+		return -ENOMSG;
+	}
+	return 0;
+}
+
+static const struct cec_adap_ops vivid_cec_adap_ops = {
+	.adap_enable = vivid_cec_adap_enable,
+	.adap_log_addr = vivid_cec_adap_log_addr,
+	.adap_transmit = vivid_cec_adap_transmit,
+	.received = vivid_received,
+};
+
+struct cec_adapter *vivid_cec_alloc_adap(struct vivid_dev *dev,
+					 unsigned int idx,
+					 struct device *parent,
+					 bool is_source)
+{
+	char name[sizeof(dev->vid_out_dev.name) + 2];
+	u32 caps = CEC_CAP_TRANSMIT | CEC_CAP_LOG_ADDRS |
+		CEC_CAP_PASSTHROUGH | CEC_CAP_RC;
+
+	snprintf(name, sizeof(name), "%s%d",
+		 is_source ? dev->vid_out_dev.name : dev->vid_cap_dev.name,
+		 idx);
+	return cec_allocate_adapter(&vivid_cec_adap_ops, dev,
+		name, caps, 1, parent);
+}