On 19 May 2015 at 23:38, David Härdeman <david@xxxxxxxxxxx> wrote:
> On Tue, Mar 31, 2015 at 08:48:06PM +0300, Antti Seppälä wrote:
>>From: James Hogan <james@xxxxxxxxxxxxx>
>>
>>Add a callback to raw ir handlers for encoding and modulating a scancode
>>to a set of raw events. This could be used for transmit, or for
>>converting a wakeup scancode filter to a form that is more suitable for
>>raw hardware wake up filters.
>>
>>Signed-off-by: James Hogan <james@xxxxxxxxxxxxx>
>>Signed-off-by: Antti Seppälä <a.seppala@xxxxxxxxx>
>>Cc: David Härdeman <david@xxxxxxxxxxx>
>>---
>>
>>Notes:
>> Changes in v3:
>> - Ported to apply against latest media-tree
>>
>> Changes in v2:
>> - Alter encode API to return -ENOBUFS when there isn't enough buffer
>> space. When this occurs all buffer contents must have been written
>> with the partial encoding of the scancode. This is to allow drivers
>> such as nuvoton-cir to provide a shorter buffer and still get a
>> useful partial encoding for the wakeup pattern.
>>
>> drivers/media/rc/rc-core-priv.h | 2 ++
>> drivers/media/rc/rc-ir-raw.c | 37 +++++++++++++++++++++++++++++++++++++
>> include/media/rc-core.h | 3 +++
>> 3 files changed, 42 insertions(+)
>>
>>diff --git a/drivers/media/rc/rc-core-priv.h b/drivers/media/rc/rc-core-priv.h
>>index b68d4f76..122c25f 100644
>>--- a/drivers/media/rc/rc-core-priv.h
>>+++ b/drivers/media/rc/rc-core-priv.h
>>@@ -25,6 +25,8 @@ struct ir_raw_handler {
>>
>> u64 protocols; /* which are handled by this handler */
>> int (*decode)(struct rc_dev *dev, struct ir_raw_event event);
>>+ int (*encode)(u64 protocols, const struct rc_scancode_filter *scancode,
>>+ struct ir_raw_event *events, unsigned int max);
>>
>> /* These two should only be used by the lirc decoder */
>> int (*raw_register)(struct rc_dev *dev);
>>diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c
>>index b732ac6..dd47fe5 100644
>>--- a/drivers/media/rc/rc-ir-raw.c
>>+++ b/drivers/media/rc/rc-ir-raw.c
>>@@ -246,6 +246,43 @@ static int change_protocol(struct rc_dev *dev, u64 *rc_type)
>> return 0;
>> }
>>
>>+/**
>>+ * ir_raw_encode_scancode() - Encode a scancode as raw events
>>+ *
>>+ * @protocols: permitted protocols
>>+ * @scancode: scancode filter describing a single scancode
>>+ * @events: array of raw events to write into
>>+ * @max: max number of raw events
>>+ *
>>+ * Attempts to encode the scancode as raw events.
>>+ *
>>+ * Returns: The number of events written.
>>+ * -ENOBUFS if there isn't enough space in the array to fit the
>>+ * encoding. In this case all @max events will have been written.
>>+ * -EINVAL if the scancode is ambiguous or invalid, or if no
>>+ * compatible encoder was found.
>>+ */
>>+int ir_raw_encode_scancode(u64 protocols,
>
> Why a bitmask of protocols and not a single protocol enum? What's the
> use case for encoding a given scancode according to one out of a number
> of protocols (and not even knowing which one)??
>
I think bitmask was used simply for consistency reasons. Most of the
rc-core handles protocols in a bitmask (u64 protocols or some variant
of it). Especially in the decoders the dev->enabled_protocols is used
to mean "decode any of these protocols but I don't care which one" and
the encoders were written to follow that logic.
>From ir driver point of view it was also kind of nice to use the u64
enabled_wakeup_protocols from struct rc_dev which already exists and
is manipulated with the same sysfs code as the enabled_protocols
bitmask.
--
Antti
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