The DVBv3 quality parameters are limited on several ways:
- Doesn't provide any way to indicate the used measure,
so userspace need to guess how to calculate the measure;
- Only a limited set of stats are supported;
- Can't be called in a way to require them to be filled
all at once (atomic reads from the hardware), with may
cause troubles on interpreting them on userspace;
- On some OFDM delivery systems, the carriers can be
independently modulated, having different properties.
Currently, there's no way to report per-layer stats.
To address the above issues, adding a new DVBv5-based stats
API.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
---
v6: Add DocBook documentation.
v7: Some fixes as suggested by Antti
V8: Documentation fix, compilation fix and name the stats struct,
for its reusage inside the core
TODO:
- Add a driver implementation.
---
Documentation/DocBook/media/dvb/dvbproperty.xml | 97 ++++++++++++++++++++++++-
include/uapi/linux/dvb/frontend.h | 83 ++++++++++++++++++++-
2 files changed, 177 insertions(+), 3 deletions(-)
diff --git a/Documentation/DocBook/media/dvb/dvbproperty.xml b/Documentation/DocBook/media/dvb/dvbproperty.xml
index 957e3ac..9168808 100644
--- a/Documentation/DocBook/media/dvb/dvbproperty.xml
+++ b/Documentation/DocBook/media/dvb/dvbproperty.xml
@@ -7,16 +7,29 @@ the capability ioctls weren't implemented yet via the new way.</para>
<para>The typical usage for the <constant>FE_GET_PROPERTY/FE_SET_PROPERTY</constant>
API is to replace the ioctl's were the <link linkend="dvb-frontend-parameters">
struct <constant>dvb_frontend_parameters</constant></link> were used.</para>
+<section id="dtv-stats">
+<title>DTV stats type</title>
+<programlisting>
+struct dtv_stats {
+ __u16 value;
+ __u8 scale;
+} __attribute__ ((packed));
+</programlisting>
+</section>
<section id="dtv-property">
<title>DTV property type</title>
<programlisting>
/* Reserved fields should be set to 0 */
+
struct dtv_property {
__u32 cmd;
union {
__u32 data;
struct {
- __u8 data[32];
+ union {
+ __u8 data[32];
+ __u16 data[16];
+ }
__u32 len;
__u32 reserved1[3];
void *reserved2;
@@ -850,6 +863,78 @@ enum fe_interleaving {
<para>use the special macro LNA_AUTO to set LNA auto</para>
</section>
</section>
+
+ <section id="frontend-qos-properties">
+ <title>Frontend Quality of Service/Statistics indicators</title>
+ <para>Except for <link linkend="DTV-QOS-ENUM"><constant>DTV_QOS_ENUM</constant></link>,
+ the values are returned via <constant>dtv_property.stat</constant>.</para>
+ <para>For most delivery systems, this will return a single value for each parameter.</para>
+ <para>It should be noticed, however, that new OFDM delivery systems
+ like ISDB can use different modulation types for each group of carriers.
+ On such standards, up to 3 groups of statistics can be provided, one
+ for each carrier group (called "layer" on ISDB).
+ In order to be consistent with other delivery systems, the first
+ value at <link linkend="dtv-stats"><constant>dtv_property.stat.dtv_stats</constant></link> array refers to
+ a global indicator, if any. The other elements of the array represent
+ each layer, starting from layer A(index 1), layer B (index 2) and so on</para>
+ <para>The number of filled elements are stored at <constant>dtv_property.stat.len</constant>.</para>
+ <para>Each element of the <constant>dtv_property.stat.dtv_stats</constant> array consists on two elements:</para>
+ <itemizedlist mark='opencircle'>
+ <listitem><para><constant>value</constant> - Value of the measure</para></listitem>
+ <listitem><para><constant>scale</constant> - Scale for the value. It can be:</para>
+ <section id = "fecap-scale-params">
+ <itemizedlist mark='bullet'>
+ <listitem><para><constant>FE_SCALE_NOT_AVAILABLE</constant> - If it is not possible to collect a given parameter (could be a transitory or permanent condition)</para></listitem>
+ <listitem><para><constant>FE_SCALE_DECIBEL</constant> - parameter is a signed value, measured in 0.1 dB</para></listitem>
+ <listitem><para><constant>FE_SCALE_RELATIVE</constant> - parameter is a unsigned value, where 0 means 0% and 65535 means 100%.</para></listitem>
+ <listitem><para><constant>FE_SCALE_COUNTER</constant> - parameter is a unsigned value that counts the occurrence of an event, like bit error, block error, or lapsed time.</para></listitem>
+ </itemizedlist>
+ </section>
+ </listitem>
+ </itemizedlist>
+ <section id="DTV-QOS-ENUM">
+ <title><constant>DTV_QOS_ENUM</constant></title>
+ <para>A frontend needs to advertise the statistics it provides. This property allows to enumerate all
+ <link linkend="frontend-qos-properties">DTV QoS statistics</link> that are
+ supported by a given frontend.</para>
+
+ <para><constant>dtv_property.len</constant> indicates the number of supported
+ <link linkend="frontend-qos-properties">DTV QoS statistics</link>.</para>
+ <para><constant>dtv_property.data16</constant> is an 16 bits array of the supported properties.</para>
+ </section>
+ <section id="DTV-QOS-SIGNAL-STRENGTH">
+ <title><constant>DTV_QOS_SIGNAL_STRENGTH</constant></title>
+ <para>Indicates the signal strength level at the analog part of the tuner.</para>
+ </section>
+ <section id="DTV-QOS-CNR">
+ <title><constant>DTV_QOS_CNR</constant></title>
+ <para>Indicates the signal to noise relation for the main carrier.</para>
+
+ </section>
+ <section id="DTV-QOS-BIT-ERROR-COUNT">
+ <title><constant>DTV_QOS_BIT_ERROR_COUNT</constant></title>
+ <para>Measures the number of bit errors since the last counter reset.</para>
+ <para>In order to get the BER (Bit Error Rate) measurement, it should be divided by
+ <link linkend="DTV-QOS-TOTAL-BITS-COUNT"><constant>DTV_QOS_TOTAL_BITS_COUNT</constant></link>.</para>
+ </section>
+ <section id="DTV-QOS-TOTAL-BITS-COUNT">
+ <title><constant>DTV_QOS_TOTAL_BITS_COUNT</constant></title>
+ <para>Measures the amount of bits received since the last <link linkend="DTV-QOS-BIT-ERROR-COUNT"><constant>DTV_QOS_BIT_ERROR_COUNT</constant></link> reset.</para>
+ </section>
+ <section id="DTV-QOS-ERROR-BLOCK-COUNT">
+ <title><constant>DTV_QOS_ERROR_BLOCK_COUNT</constant></title>
+ <para>Measures the number of block errors since the last counter reset.</para>
+ </section>
+ <section id="DTV-QOS-TOTAL-BLOCKS-COUNT">
+ <title><constant>DTV-QOS_TOTAL_BLOCKS_COUNT</constant></title>
+ <para>Measures the total number of blocks since the last
+ <link linkend="DTV-QOS-ERROR-BLOCK-COUNT"><constant>DTV_QOS_ERROR_BLOCK_COUNT</constant></link> reset.</para>
+ <para>It can be used to calculate the PER indicator, by dividing
+ <link linkend="DTV-QOS-ERROR-BLOCK-COUNT"><constant>DTV_QOS_ERROR_BLOCK_COUNT</constant></link>
+ by <link linkend="DTV-QOS-TOTAL-BLOCKS-COUNT"><constant>DTV-QOS-TOTAL-BLOCKS-COUNT</constant></link>.</para>
+ </section>
+ </section>
+
<section id="frontend-property-terrestrial-systems">
<title>Properties used on terrestrial delivery systems</title>
<section id="dvbt-params">
@@ -871,6 +956,7 @@ enum fe_interleaving {
<listitem><para><link linkend="DTV-HIERARCHY"><constant>DTV_HIERARCHY</constant></link></para></listitem>
<listitem><para><link linkend="DTV-LNA"><constant>DTV_LNA</constant></link></para></listitem>
</itemizedlist>
+ <para>In addition, the <link linkend="frontend-qos-properties">DTV QoS statistics</link> are also valid.</para>
</section>
<section id="dvbt2-params">
<title>DVB-T2 delivery system</title>
@@ -895,6 +981,7 @@ enum fe_interleaving {
<listitem><para><link linkend="DTV-STREAM-ID"><constant>DTV_STREAM_ID</constant></link></para></listitem>
<listitem><para><link linkend="DTV-LNA"><constant>DTV_LNA</constant></link></para></listitem>
</itemizedlist>
+ <para>In addition, the <link linkend="frontend-qos-properties">DTV QoS statistics</link> are also valid.</para>
</section>
<section id="isdbt">
<title>ISDB-T delivery system</title>
@@ -948,6 +1035,7 @@ enum fe_interleaving {
<listitem><para><link linkend="DTV-ISDBT-LAYER-SEGMENT-COUNT"><constant>DTV_ISDBT_LAYERC_SEGMENT_COUNT</constant></link></para></listitem>
<listitem><para><link linkend="DTV-ISDBT-LAYER-TIME-INTERLEAVING"><constant>DTV_ISDBT_LAYERC_TIME_INTERLEAVING</constant></link></para></listitem>
</itemizedlist>
+ <para>In addition, the <link linkend="frontend-qos-properties">DTV QoS statistics</link> are also valid.</para>
</section>
<section id="atsc-params">
<title>ATSC delivery system</title>
@@ -961,6 +1049,7 @@ enum fe_interleaving {
<listitem><para><link linkend="DTV-MODULATION"><constant>DTV_MODULATION</constant></link></para></listitem>
<listitem><para><link linkend="DTV-BANDWIDTH-HZ"><constant>DTV_BANDWIDTH_HZ</constant></link></para></listitem>
</itemizedlist>
+ <para>In addition, the <link linkend="frontend-qos-properties">DTV QoS statistics</link> are also valid.</para>
</section>
<section id="atscmh-params">
<title>ATSC-MH delivery system</title>
@@ -988,6 +1077,7 @@ enum fe_interleaving {
<listitem><para><link linkend="DTV-ATSCMH-SCCC-CODE-MODE-C"><constant>DTV_ATSCMH_SCCC_CODE_MODE_C</constant></link></para></listitem>
<listitem><para><link linkend="DTV-ATSCMH-SCCC-CODE-MODE-D"><constant>DTV_ATSCMH_SCCC_CODE_MODE_D</constant></link></para></listitem>
</itemizedlist>
+ <para>In addition, the <link linkend="frontend-qos-properties">DTV QoS statistics</link> are also valid.</para>
</section>
<section id="dtmb-params">
<title>DTMB delivery system</title>
@@ -1007,6 +1097,7 @@ enum fe_interleaving {
<listitem><para><link linkend="DTV-INTERLEAVING"><constant>DTV_INTERLEAVING</constant></link></para></listitem>
<listitem><para><link linkend="DTV-LNA"><constant>DTV_LNA</constant></link></para></listitem>
</itemizedlist>
+ <para>In addition, the <link linkend="frontend-qos-properties">DTV QoS statistics</link> are also valid.</para>
</section>
</section>
<section id="frontend-property-cable-systems">
@@ -1028,6 +1119,7 @@ enum fe_interleaving {
<listitem><para><link linkend="DTV-INNER-FEC"><constant>DTV_INNER_FEC</constant></link></para></listitem>
<listitem><para><link linkend="DTV-LNA"><constant>DTV_LNA</constant></link></para></listitem>
</itemizedlist>
+ <para>In addition, the <link linkend="frontend-qos-properties">DTV QoS statistics</link> are also valid.</para>
</section>
<section id="dvbc-annex-b-params">
<title>DVB-C Annex B delivery system</title>
@@ -1043,6 +1135,7 @@ enum fe_interleaving {
<listitem><para><link linkend="DTV-INVERSION"><constant>DTV_INVERSION</constant></link></para></listitem>
<listitem><para><link linkend="DTV-LNA"><constant>DTV_LNA</constant></link></para></listitem>
</itemizedlist>
+ <para>In addition, the <link linkend="frontend-qos-properties">DTV QoS statistics</link> are also valid.</para>
</section>
</section>
<section id="frontend-property-satellital-systems">
@@ -1062,6 +1155,7 @@ enum fe_interleaving {
<listitem><para><link linkend="DTV-VOLTAGE"><constant>DTV_VOLTAGE</constant></link></para></listitem>
<listitem><para><link linkend="DTV-TONE"><constant>DTV_TONE</constant></link></para></listitem>
</itemizedlist>
+ <para>In addition, the <link linkend="frontend-qos-properties">DTV QoS statistics</link> are also valid.</para>
<para>Future implementations might add those two missing parameters:</para>
<itemizedlist mark='opencircle'>
<listitem><para><link linkend="DTV-DISEQC-MASTER"><constant>DTV_DISEQC_MASTER</constant></link></para></listitem>
@@ -1077,6 +1171,7 @@ enum fe_interleaving {
<listitem><para><link linkend="DTV-ROLLOFF"><constant>DTV_ROLLOFF</constant></link></para></listitem>
<listitem><para><link linkend="DTV-STREAM-ID"><constant>DTV_STREAM_ID</constant></link></para></listitem>
</itemizedlist>
+ <para>In addition, the <link linkend="frontend-qos-properties">DTV QoS statistics</link> are also valid.</para>
</section>
<section id="turbo-params">
<title>Turbo code delivery system</title>
diff --git a/include/uapi/linux/dvb/frontend.h b/include/uapi/linux/dvb/frontend.h
index c12d452..437c440 100644
--- a/include/uapi/linux/dvb/frontend.h
+++ b/include/uapi/linux/dvb/frontend.h
@@ -365,7 +365,16 @@ struct dvb_frontend_event {
#define DTV_INTERLEAVING 60
#define DTV_LNA 61
-#define DTV_MAX_COMMAND DTV_LNA
+/* Quality parameters */
+#define DTV_QOS_ENUM 62
+#define DTV_QOS_SIGNAL_STRENGTH 63
+#define DTV_QOS_CNR 64
+#define DTV_QOS_BIT_ERROR_COUNT 65
+#define DTV_QOS_TOTAL_BITS_COUNT 66
+#define DTV_QOS_ERROR_BLOCK_COUNT 67
+#define DTV_QOS_TOTAL_BLOCKS_COUNT 68
+
+#define DTV_MAX_COMMAND DTV_QOS_TOTAL_BLOCKS_COUNT
typedef enum fe_pilot {
PILOT_ON,
@@ -452,13 +461,83 @@ struct dtv_cmds_h {
__u32 reserved:30; /* Align */
};
+/**
+ * Scale types for the quality parameters.
+ * @FE_SCALE_NOT_AVAILABLE: That QoS measure is not available. That
+ * could indicate a temporary or a permanent
+ * condition.
+ * @FE_SCALE_DECIBEL: The scale is measured in 0.1 dB steps, typically
+ * used on signal measures.
+ * @FE_SCALE_RELATIVE: The scale is a relative percentual measure,
+ * ranging from 0 (0%) to 0xffff (100%).
+ * @FE_SCALE_COUNTER: The scale counts the occurrence of an event, like
+ * bit error, block error, lapsed time.
+ */
+enum fecap_scale_params {
+ FE_SCALE_NOT_AVAILABLE,
+ FE_SCALE_DECIBEL,
+ FE_SCALE_RELATIVE,
+ FE_SCALE_COUNTER
+};
+
+/**
+ * struct dtv_stats - Used for reading a DTV status property
+ *
+ * @value: value of the measure. Should range from 0 to 0xffff;
+ * @scale: Filled with enum fecap_scale_params - the scale
+ * in usage for that parameter
+ *
+ * For most delivery systems, this will return a single value for each
+ * parameter.
+ * It should be noticed, however, that new OFDM delivery systems like
+ * ISDB can use different modulation types for each group of carriers.
+ * On such standards, up to 8 groups of statistics can be provided, one
+ * for each carrier group (called "layer" on ISDB).
+ * In order to be consistent with other delivery systems, the first
+ * value refers to the entire set of carriers ("global").
+ * dtv_status:scale should use the value FE_SCALE_NOT_AVAILABLE when
+ * the value for the entire group of carriers or from one specific layer
+ * is not provided by the hardware.
+ * st.len should be filled with the latest filled status + 1.
+ *
+ * In other words, for ISDB, those values should be filled like:
+ * u.st.stat.svalue[0] = global statistics;
+ * u.st.stat.scale[0] = FE_SCALE_DECIBELS;
+ * u.st.stat.value[1] = layer A statistics;
+ * u.st.stat.scale[1] = FE_SCALE_NOT_AVAILABLE (if not available);
+ * u.st.stat.svalue[2] = layer B statistics;
+ * u.st.stat.scale[2] = FE_SCALE_DECIBELS;
+ * u.st.stat.svalue[3] = layer C statistics;
+ * u.st.stat.scale[3] = FE_SCALE_DECIBELS;
+ * u.st.len = 4;
+ */
+struct dtv_stats {
+ __u8 scale; /* enum fecap_scale_params type */\
+ union {
+ __u16 uvalue; /* for counters and relative scales */
+ __s16 svalue; /* for 0.1 dB measures */
+ };
+} __attribute__ ((packed));
+
+
+#define MAX_QOS_STATS 4
+
+struct dtv_fe_stats {
+ __u8 len;
+ struct dtv_stats stat[MAX_QOS_STATS];
+} __attribute__ ((packed));
+
struct dtv_property {
__u32 cmd;
__u32 reserved[3];
union {
__u32 data;
+ struct dtv_fe_stats st;
struct {
- __u8 data[32];
+ union {
+ __u8 data[32];
+ __u16 data16[16];
+ };
__u32 len;
__u32 reserved1[3];
void *reserved2;
--
1.7.11.7
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