media: cec: add CEC_EVENT_PIN_HPD_LOW/HIGH events

Add support for two new low-level events: PIN_HPD_LOW and PIN_HPD_HIGH.

This is specifically meant for use with the upcoming cec-gpio driver
and makes it possible to trace when the HPD pin changes. Some HDMI
sinks do strange things with the HPD and this makes it easy to debug
this.

Note that this also moves the initialization of a devnode mutex and
list to the allocate_adapter function: if the HPD is high, then as
soon as the HPD interrupt is created an interrupt occurs and
cec_queue_pin_hpd_event() is called which requires that the devnode
mutex and list are initialized.

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

diff --git a/drivers/media/cec/cec-adap.c b/drivers/media/cec/cec-adap.c
index 84d1b67f850ce83b297a59a36e1c44391ac9780f..dd0c9cacd1d0964a212f4fe60cba873569e750d7 100644 (file)
--- a/drivers/media/cec/cec-adap.c
+++ b/drivers/media/cec/cec-adap.c
@@ -86,7 +86,7 @@ void cec_queue_event_fh(struct cec_fh *fh,
                        const struct cec_event *new_ev, u64 ts)
 {
        static const u8 max_events[CEC_NUM_EVENTS] = {
-               1, 1, 64, 64,
+               1, 1, 64, 64, 8, 8,
        };
        struct cec_event_entry *entry;
        unsigned int ev_idx = new_ev->event - 1;
@@ -170,6 +170,22 @@ void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high, ktime_t ts)
 }
 EXPORT_SYMBOL_GPL(cec_queue_pin_cec_event);
 
+/* Notify userspace that the HPD pin changed state at the given time. */
+void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts)
+{
+       struct cec_event ev = {
+               .event = is_high ? CEC_EVENT_PIN_HPD_HIGH :
+                                  CEC_EVENT_PIN_HPD_LOW,
+       };
+       struct cec_fh *fh;
+
+       mutex_lock(&adap->devnode.lock);
+       list_for_each_entry(fh, &adap->devnode.fhs, list)
+               cec_queue_event_fh(fh, &ev, ktime_to_ns(ts));
+       mutex_unlock(&adap->devnode.lock);
+}
+EXPORT_SYMBOL_GPL(cec_queue_pin_hpd_event);
+
 /*
  * Queue a new message for this filehandle.
  *

diff --git a/drivers/media/cec/cec-api.c b/drivers/media/cec/cec-api.c
index a079f7fe018c4ab2529f30e6b412ee51aef4bae1..465bb3ec21f650ed8afd7c69c2b3ffb3403cf824 100644 (file)
--- a/drivers/media/cec/cec-api.c
+++ b/drivers/media/cec/cec-api.c
@@ -529,7 +529,7 @@ static int cec_open(struct inode *inode, struct file *filp)
         * Initial events that are automatically sent when the cec device is
         * opened.
         */
-       struct cec_event ev_state = {
+       struct cec_event ev = {
                .event = CEC_EVENT_STATE_CHANGE,
                .flags = CEC_EVENT_FL_INITIAL_STATE,
        };
@@ -569,9 +569,19 @@ static int cec_open(struct inode *inode, struct file *filp)
        filp->private_data = fh;
 
        /* Queue up initial state events */
-       ev_state.state_change.phys_addr = adap->phys_addr;
-       ev_state.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
-       cec_queue_event_fh(fh, &ev_state, 0);
+       ev.state_change.phys_addr = adap->phys_addr;
+       ev.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
+       cec_queue_event_fh(fh, &ev, 0);
+#ifdef CONFIG_CEC_PIN
+       if (adap->pin && adap->pin->ops->read_hpd) {
+               err = adap->pin->ops->read_hpd(adap);
+               if (err >= 0) {
+                       ev.event = err ? CEC_EVENT_PIN_HPD_HIGH :
+                                        CEC_EVENT_PIN_HPD_LOW;
+                       cec_queue_event_fh(fh, &ev, 0);
+               }
+       }
+#endif
 
        list_add(&fh->list, &devnode->fhs);
        mutex_unlock(&devnode->lock);

diff --git a/drivers/media/cec/cec-core.c b/drivers/media/cec/cec-core.c
index 648136e552d5bcbb6c553c96fe2116c0c4919c2c..e3a1fb6d6690dd5049303d0967f779f91d87e87f 100644 (file)
--- a/drivers/media/cec/cec-core.c
+++ b/drivers/media/cec/cec-core.c
@@ -112,10 +112,6 @@ static int __must_check cec_devnode_register(struct cec_devnode *devnode,
        int minor;
        int ret;
 
-       /* Initialization */
-       INIT_LIST_HEAD(&devnode->fhs);
-       mutex_init(&devnode->lock);
-
        /* Part 1: Find a free minor number */
        mutex_lock(&cec_devnode_lock);
        minor = find_next_zero_bit(cec_devnode_nums, CEC_NUM_DEVICES, 0);
@@ -242,6 +238,10 @@ struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
        INIT_LIST_HEAD(&adap->wait_queue);
        init_waitqueue_head(&adap->kthread_waitq);
 
+       /* adap->devnode initialization */
+       INIT_LIST_HEAD(&adap->devnode.fhs);
+       mutex_init(&adap->devnode.lock);
+
        adap->kthread = kthread_run(cec_thread_func, adap, "cec-%s", name);
        if (IS_ERR(adap->kthread)) {
                pr_err("cec-%s: kernel_thread() failed\n", name);

diff --git a/include/media/cec-pin.h b/include/media/cec-pin.h
index f09cc9579d53d19259419930b3d7d4c6a2a4e5a0..ea84b9c9e0c353a09f50a80f7571b0fa06b22a3f 100644 (file)
--- a/include/media/cec-pin.h
+++ b/include/media/cec-pin.h
@@ -97,6 +97,9 @@ enum cec_pin_state {
  * @free:      optional. Free any allocated resources. Called when the
  *             adapter is deleted.
  * @status:    optional, log status information.
+ * @read_hpd:  read the HPD pin. Return true if high, false if low or
+ *             an error if negative. If NULL or -ENOTTY is returned,
+ *             then this is not supported.
  *
  * These operations are used by the cec pin framework to manipulate
  * the CEC pin.
@@ -109,6 +112,7 @@ struct cec_pin_ops {
        void (*disable_irq)(struct cec_adapter *adap);
        void (*free)(struct cec_adapter *adap);
        void (*status)(struct cec_adapter *adap, struct seq_file *file);
+       int  (*read_hpd)(struct cec_adapter *adap);
 };
 
 #define CEC_NUM_PIN_EVENTS 128

diff --git a/include/media/cec.h b/include/media/cec.h
index df6b3bd3128493faf154834b421ab42345d6430c..9d0f983faea96bf7ce56172bc560ca0a91d09d05 100644 (file)
--- a/include/media/cec.h
+++ b/include/media/cec.h
@@ -91,7 +91,7 @@ struct cec_event_entry {
 };
 
 #define CEC_NUM_CORE_EVENTS 2
-#define CEC_NUM_EVENTS CEC_EVENT_PIN_CEC_HIGH
+#define CEC_NUM_EVENTS CEC_EVENT_PIN_HPD_HIGH
 
 struct cec_fh {
        struct list_head        list;
@@ -296,6 +296,16 @@ static inline void cec_received_msg(struct cec_adapter *adap,
 void cec_queue_pin_cec_event(struct cec_adapter *adap,
                             bool is_high, ktime_t ts);
 
+/**
+ * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp.
+ *
+ * @adap:      pointer to the cec adapter
+ * @is_high:   when true the HPD pin is high, otherwise it is low
+ * @ts:                the timestamp for this event
+ *
+ */
+void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
+
 /**
  * cec_get_edid_phys_addr() - find and return the physical address
  *

diff --git a/include/uapi/linux/cec.h b/include/uapi/linux/cec.h
index 4351c3481aea19720c2c96130f3a642bb5bfb44d..b9f8df3a0477e6c32881105c097192493f4ad9e2 100644 (file)
--- a/include/uapi/linux/cec.h
+++ b/include/uapi/linux/cec.h
@@ -410,6 +410,8 @@ struct cec_log_addrs {
 #define CEC_EVENT_LOST_MSGS            2
 #define CEC_EVENT_PIN_CEC_LOW          3
 #define CEC_EVENT_PIN_CEC_HIGH         4
+#define CEC_EVENT_PIN_HPD_LOW          5
+#define CEC_EVENT_PIN_HPD_HIGH         6
 
 #define CEC_EVENT_FL_INITIAL_STATE     (1 << 0)
 #define CEC_EVENT_FL_DROPPED_EVENTS    (1 << 1)