Return-Path: MIME-Version: 1.0 In-Reply-To: <00d001cfccdf$b86eb4b0$294c1e10$@samsung.com> References: <1410253830-7866-1-git-send-email-vikram.pal@samsung.com> <00d001cfccdf$b86eb4b0$294c1e10$@samsung.com> Date: Wed, 10 Sep 2014 15:49:17 +0300 Message-ID: Subject: Re: [PATCH v2] monitor: Add AVRCP GetElementAttributes From: Luiz Augusto von Dentz To: Vikrampal Cc: "linux-bluetooth@vger.kernel.org" , Dmitry Kasatkin , cpgs@samsung.com Content-Type: text/plain; charset=UTF-8 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Vikram, On Wed, Sep 10, 2014 at 1:12 PM, Vikrampal wrote: > Hi Luiz, > >> -----Original Message----- >> From: Luiz Augusto von Dentz [mailto:luiz.dentz@gmail.com] >> Sent: Wednesday, September 10, 2014 2:42 PM >> To: Vikrampal Yadav >> Cc: linux-bluetooth@vger.kernel.org; Dmitry Kasatkin; cpgs@samsung.com >> Subject: Re: [PATCH v2] monitor: Add AVRCP GetElementAttributes >> >> Hi Vikram, >> >> On Tue, Sep 9, 2014 at 12:10 PM, Vikrampal Yadav >> wrote: >> > Support for decoding AVRCP GetElementAttributes added in Bluetooth >> > monitor. >> > --- >> > monitor/avctp.c | 158 >> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >> > monitor/l2cap.h | 16 +++--- >> > 2 files changed, 167 insertions(+), 7 deletions(-) >> > >> > diff --git a/monitor/avctp.c b/monitor/avctp.c index c7e242b..89f0f9c >> > 100644 >> > --- a/monitor/avctp.c >> > +++ b/monitor/avctp.c >> > @@ -158,6 +158,21 @@ >> > #define AVRCP_ATTRIBUTE_SHUFFLE 0x03 >> > #define AVRCP_ATTRIBUTE_SCAN 0x04 >> > >> > +/* media attributes */ >> > +#define AVRCP_MEDIA_ATTRIBUTE_ILLEGAL 0x00 >> > +#define AVRCP_MEDIA_ATTRIBUTE_TITLE 0x01 >> > +#define AVRCP_MEDIA_ATTRIBUTE_ARTIST 0x02 >> > +#define AVRCP_MEDIA_ATTRIBUTE_ALBUM 0x03 >> > +#define AVRCP_MEDIA_ATTRIBUTE_TRACK 0x04 >> > +#define AVRCP_MEDIA_ATTRIBUTE_TOTAL 0x05 >> > +#define AVRCP_MEDIA_ATTRIBUTE_GENRE 0x06 >> > +#define AVRCP_MEDIA_ATTRIBUTE_DURATION 0x07 >> > + >> > +static struct avrcp_continuing { >> > + uint16_t num; >> > + uint16_t size; >> > +} avrcp_continuing; >> > + >> > static const char *ctype2str(uint8_t ctype) { >> > switch (ctype & 0x0f) { >> > @@ -517,6 +532,30 @@ static const char *charset2str(uint16_t charset) >> > } >> > } >> > >> > +static const char *mediattr2str(uint32_t attr) { >> > + switch (attr) { >> > + case AVRCP_MEDIA_ATTRIBUTE_ILLEGAL: >> > + return "Illegal"; >> > + case AVRCP_MEDIA_ATTRIBUTE_TITLE: >> > + return "Title"; >> > + case AVRCP_MEDIA_ATTRIBUTE_ARTIST: >> > + return "Artist"; >> > + case AVRCP_MEDIA_ATTRIBUTE_ALBUM: >> > + return "Album"; >> > + case AVRCP_MEDIA_ATTRIBUTE_TRACK: >> > + return "Track"; >> > + case AVRCP_MEDIA_ATTRIBUTE_TOTAL: >> > + return "Track Total"; >> > + case AVRCP_MEDIA_ATTRIBUTE_GENRE: >> > + return "Genre"; >> > + case AVRCP_MEDIA_ATTRIBUTE_DURATION: >> > + return "Track duration"; >> > + default: >> > + return "Reserved"; >> > + } >> > +} >> > + >> > static bool avrcp_passthrough_packet(struct l2cap_frame *frame) { >> > packet_hexdump(frame->data, frame->size); @@ -884,6 +923,122 >> > @@ static bool avrcp_displayable_charset(struct l2cap_frame *frame, >> uint8_t ctype, >> > return true; >> > } >> > >> > +static bool avrcp_get_element_attributes(struct l2cap_frame *frame, >> > + uint8_t ctype, uint8_t len, >> > + uint8_t indent) { >> > + uint64_t id; >> > + uint8_t num; >> > + >> > + if (ctype > AVC_CTYPE_GENERAL_INQUIRY) >> > + goto response; >> > + >> > + if (!l2cap_frame_get_be64(frame, &id)) >> > + return false; >> > + >> > + print_field("%*cIdentifier: 0x%jx (%s)", (indent - 8), ' ', >> > + id, id ? "Reserved" : >> > + "PLAYING"); >> > + >> > + if (!l2cap_frame_get_u8(frame, &num)) >> > + return false; >> > + >> > + print_field("%*cAttributeCount: 0x%02x", (indent - 8), ' ', >> > + num); >> > + >> > + for (; num > 0; num--) { >> > + uint32_t attr; >> > + >> > + if (!l2cap_frame_get_be32(frame, &attr)) >> > + return false; >> > + >> > + print_field("%*cAttribute: 0x%08x (%s)", (indent - 8), >> > + ' ', attr, mediattr2str(attr)); >> > + } >> > + >> > + return true; >> > + >> > +response: >> > + if (frame->pkt_type == AVRCP_PACKET_TYPE_SINGLE >> > + || frame->pkt_type == AVRCP_PACKET_TYPE_START) { >> > + if (!l2cap_frame_get_u8(frame, &num)) >> > + return false; >> > + >> > + avrcp_continuing.num = num; >> > + print_field("%*cAttributeCount: 0x%02x", (indent - 8), >> > + ' ', num); >> > + len--; >> > + } else { >> > + num = avrcp_continuing.num; >> > + >> > + if (avrcp_continuing.size > 0) { >> > + uint16_t size; >> > + >> > + if (avrcp_continuing.size > len) { >> > + size = len; >> > + avrcp_continuing.size -= len; >> > + } else { >> > + size = avrcp_continuing.size; >> > + avrcp_continuing.size = 0; >> > + } >> > + >> > + printf("ContinuingAttributeValue: "); >> > + for (; size > 0; size--) { >> > + uint8_t c; >> > + >> > + if (!l2cap_frame_get_u8(frame, &c)) >> > + return false; >> > + >> > + printf("%1c", isprint(c) ? c : '.'); >> > + } >> > + printf("\n"); >> > + >> > + len -= size; >> > + } >> > + } >> > + >> > + while (num > 0 && len > 0) { >> > + uint32_t attr; >> > + uint16_t charset, attrlen; >> > + >> > + if (!l2cap_frame_get_be32(frame, &attr)) >> > + return false; >> > + >> > + print_field("%*cAttribute: 0x%08x (%s)", (indent - 8), >> > + ' ', attr, >> > + mediattr2str(attr)); >> > + >> > + if (!l2cap_frame_get_be16(frame, &charset)) >> > + return false; >> > + >> > + print_field("%*cCharsetID: 0x%04x (%s)", (indent - 8), >> > + ' ', charset, charset2str(charset)); >> > + >> > + if (!l2cap_frame_get_be16(frame, &attrlen)) >> > + return false; >> > + >> > + print_field("%*cAttributeValueLength: 0x%04x", >> > + (indent - 8), ' ', >> > + attrlen); >> > + >> > + len -= sizeof(attr) + sizeof(charset) + sizeof(attrlen); >> > + num--; >> > + >> > + print_field("%*cAttributeValue: ", (indent - 8), ' '); >> > + for (; attrlen > 0 && len > 0; attrlen--, len--) { >> > + uint8_t c; >> > + >> > + if (!l2cap_frame_get_u8(frame, &c)) >> > + return false; >> > + >> > + printf("%1c", isprint(c) ? c : '.'); >> > + } >> > + >> > + if (attrlen > 0) >> > + avrcp_continuing.size = attrlen; >> > + } >> > + >> > + avrcp_continuing.num = num; >> > + >> > + return true; >> > +} >> > + >> > struct avrcp_ctrl_pdu_data { >> > uint8_t pduid; >> > bool (*func) (struct l2cap_frame *frame, uint8_t ctype, >> > uint8_t len, @@ -899,6 +1054,7 @@ static const struct >> avrcp_ctrl_pdu_data avrcp_ctrl_pdu_table[] = { >> > { 0x15, avrcp_get_player_attribute_text }, >> > { 0x16, avrcp_get_player_value_text }, >> > { 0x17, avrcp_displayable_charset }, >> > + { 0x20, avrcp_get_element_attributes }, >> > { } >> > }; >> > >> > @@ -932,6 +1088,8 @@ static bool avrcp_pdu_packet(struct l2cap_frame >> *frame, uint8_t ctype, >> > if (!l2cap_frame_get_be16(frame, &len)) >> > return false; >> > >> > + frame->pkt_type = pt; >> > + >> >> This does not belong here, you should probably pass pt in the callback not >> via frame, or even better have AVCTP frame representation which points to >> the L2CAP frame that one can contain things AVCTP specifics like pt. > > Currently, I see only this information to be saved. So, can we not declare a static > variable pkt_type in avctp.c. Later on, if more information need to be saved then > we can define a frame structure. I would probably pass pt to avrcp_packet to be forward to the callback just as you did with hdr, but I still think and AVCTP frame representation would be better as it can grow without always having to change the callbacks in the pdu table e.g.: struct avctp_frame { uint8_t hdr; uint8_t pt; struct l2cap_frame l2cap_frame; }; -- Luiz Augusto von Dentz