[media] cec: add proper support for CDC-Only CEC devices

CDC-Only CEC devices are CEC devices that can only handle CDC messages,
all other messages are ignored.

Add a flag to signal that this is a CDC-Only device and act accordingly.

Also add helper functions to identify if a CEC device is configured as a
CDC-Only device, a second TV, a switch or a processor, since these variations
cannot be determined by the logical address alone.

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

diff --git a/drivers/staging/media/cec/TODO b/drivers/staging/media/cec/TODO
index 5a4cfdf..504d35c 100644 (file)
--- a/drivers/staging/media/cec/TODO
+++ b/drivers/staging/media/cec/TODO
@@ -1,9 +1,5 @@
 TODOs:
 
-- Should CEC_LOG_ADDR_TYPE_SPECIFIC be replaced by TYPE_2ND_TV and TYPE_PROCESSOR?
-  And also TYPE_SWITCH and TYPE_CDC_ONLY in addition to the TYPE_UNREGISTERED?
-  This should give the framework more information about the device type
-  since SPECIFIC and UNREGISTERED give no useful information.
 - Once this is out of staging this should no longer be a separate
   config option, instead it should be selected by drivers that want it.
 - Revisit the IS_REACHABLE(RC_CORE): perhaps the RC_CORE support should

diff --git a/drivers/staging/media/cec/cec-adap.c b/drivers/staging/media/cec/cec-adap.c
index a65d866..054cd06 100644 (file)
--- a/drivers/staging/media/cec/cec-adap.c
+++ b/drivers/staging/media/cec/cec-adap.c
@@ -1233,7 +1233,8 @@ configured:
        mutex_unlock(&adap->lock);
 
        for (i = 0; i < las->num_log_addrs; i++) {
-               if (las->log_addr[i] == CEC_LOG_ADDR_INVALID)
+               if (las->log_addr[i] == CEC_LOG_ADDR_INVALID ||
+                   (las->flags & CEC_LOG_ADDRS_FL_CDC_ONLY))
                        continue;
 
                /*
@@ -1355,6 +1356,29 @@ int __cec_s_log_addrs(struct cec_adapter *adap,
                return 0;
        }
 
+       if (log_addrs->flags & CEC_LOG_ADDRS_FL_CDC_ONLY) {
+               /*
+                * Sanitize log_addrs fields if a CDC-Only device is
+                * requested.
+                */
+               log_addrs->num_log_addrs = 1;
+               log_addrs->osd_name[0] = '\0';
+               log_addrs->vendor_id = CEC_VENDOR_ID_NONE;
+               log_addrs->log_addr_type[0] = CEC_LOG_ADDR_TYPE_UNREGISTERED;
+               /*
+                * This is just an internal convention since a CDC-Only device
+                * doesn't have to be a switch. But switches already use
+                * unregistered, so it makes some kind of sense to pick this
+                * as the primary device. Since a CDC-Only device never sends
+                * any 'normal' CEC messages this primary device type is never
+                * sent over the CEC bus.
+                */
+               log_addrs->primary_device_type[0] = CEC_OP_PRIM_DEVTYPE_SWITCH;
+               log_addrs->all_device_types[0] = 0;
+               log_addrs->features[0][0] = 0;
+               log_addrs->features[0][1] = 0;
+       }
+
        /* Ensure the osd name is 0-terminated */
        log_addrs->osd_name[sizeof(log_addrs->osd_name) - 1] = '\0';
 
@@ -1575,6 +1599,11 @@ static int cec_receive_notify(struct cec_adapter *adap, struct cec_msg *msg,
 
        dprintk(1, "cec_receive_notify: %*ph\n", msg->len, msg->msg);
 
+       /* If this is a CDC-Only device, then ignore any non-CDC messages */
+       if (cec_is_cdc_only(&adap->log_addrs) &&
+           msg->msg[1] != CEC_MSG_CDC_MESSAGE)
+               return 0;
+
        if (adap->ops->received) {
                /* Allow drivers to process the message first */
                if (adap->ops->received(adap, msg) != -ENOMSG)

diff --git a/drivers/staging/media/cec/cec-api.c b/drivers/staging/media/cec/cec-api.c
index 54148a6..d4bc4ee 100644 (file)
--- a/drivers/staging/media/cec/cec-api.c
+++ b/drivers/staging/media/cec/cec-api.c
@@ -163,7 +163,8 @@ static long cec_adap_s_log_addrs(struct cec_adapter *adap, struct cec_fh *fh,
        if (copy_from_user(&log_addrs, parg, sizeof(log_addrs)))
                return -EFAULT;
        log_addrs.flags &= CEC_LOG_ADDRS_FL_ALLOW_UNREG_FALLBACK |
-                          CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU;
+                          CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU |
+                          CEC_LOG_ADDRS_FL_CDC_ONLY;
        mutex_lock(&adap->lock);
        if (!adap->is_configuring &&
            (!log_addrs.num_log_addrs || !adap->is_configured) &&
@@ -190,6 +191,12 @@ static long cec_transmit(struct cec_adapter *adap, struct cec_fh *fh,
                return -ENOTTY;
        if (copy_from_user(&msg, parg, sizeof(msg)))
                return -EFAULT;
+
+       /* A CDC-Only device can only send CDC messages */
+       if ((adap->log_addrs.flags & CEC_LOG_ADDRS_FL_CDC_ONLY) &&
+           (msg.len == 1 || msg.msg[1] != CEC_MSG_CDC_MESSAGE))
+               return -EINVAL;
+
        msg.flags &= CEC_MSG_FL_REPLY_TO_FOLLOWERS;
        mutex_lock(&adap->lock);
        if (!adap->is_configured)

diff --git a/include/linux/cec.h b/include/linux/cec.h
index 3f2f076..9c87711 100644 (file)
--- a/include/linux/cec.h
+++ b/include/linux/cec.h
@@ -396,6 +396,8 @@ struct cec_log_addrs {
 #define CEC_LOG_ADDRS_FL_ALLOW_UNREG_FALLBACK  (1 << 0)
 /* Passthrough RC messages to the input subsystem */
 #define CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU     (1 << 1)
+/* CDC-Only device: supports only CDC messages */
+#define CEC_LOG_ADDRS_FL_CDC_ONLY              (1 << 2)
 
 /* Events */
 
@@ -1016,4 +1018,54 @@ struct cec_event {
 #define CEC_OP_HPD_ERROR_OTHER                         3
 #define CEC_OP_HPD_ERROR_NONE_NO_VIDEO                 4
 
+/* End of Messages */
+
+/* Helper functions to identify the 'special' CEC devices */
+
+static inline bool cec_is_2nd_tv(const struct cec_log_addrs *las)
+{
+       /*
+        * It is a second TV if the logical address is 14 or 15 and the
+        * primary device type is a TV.
+        */
+       return las->num_log_addrs &&
+              las->log_addr[0] >= CEC_LOG_ADDR_SPECIFIC &&
+              las->primary_device_type[0] == CEC_OP_PRIM_DEVTYPE_TV;
+}
+
+static inline bool cec_is_processor(const struct cec_log_addrs *las)
+{
+       /*
+        * It is a processor if the logical address is 12-15 and the
+        * primary device type is a Processor.
+        */
+       return las->num_log_addrs &&
+              las->log_addr[0] >= CEC_LOG_ADDR_BACKUP_1 &&
+              las->primary_device_type[0] == CEC_OP_PRIM_DEVTYPE_PROCESSOR;
+}
+
+static inline bool cec_is_switch(const struct cec_log_addrs *las)
+{
+       /*
+        * It is a switch if the logical address is 15 and the
+        * primary device type is a Switch and the CDC-Only flag is not set.
+        */
+       return las->num_log_addrs == 1 &&
+              las->log_addr[0] == CEC_LOG_ADDR_UNREGISTERED &&
+              las->primary_device_type[0] == CEC_OP_PRIM_DEVTYPE_SWITCH &&
+              !(las->flags & CEC_LOG_ADDRS_FL_CDC_ONLY);
+}
+
+static inline bool cec_is_cdc_only(const struct cec_log_addrs *las)
+{
+       /*
+        * It is a CDC-only device if the logical address is 15 and the
+        * primary device type is a Switch and the CDC-Only flag is set.
+        */
+       return las->num_log_addrs == 1 &&
+              las->log_addr[0] == CEC_LOG_ADDR_UNREGISTERED &&
+              las->primary_device_type[0] == CEC_OP_PRIM_DEVTYPE_SWITCH &&
+              (las->flags & CEC_LOG_ADDRS_FL_CDC_ONLY);
+}
+
 #endif