kingst-la2016: rephrase samplerate list code path, prepare 500MHz

Rephrase the config_list() SR_CONF_SAMPLERATE branch for improved
readability. A list of supported rates gets derived from the current
device's maximum rate. Naming the tables after device models instead
of maximum rates is unexpected.

Drop the "odd" looking 4/8MHz items. Which results in consistent 1/2/5
steps in all decades. With hardware compression there is no gain to be
expected from using 4/8MHz instead of 5/10MHz. (Vendor software does
not provide that choice either.)

Add a list of samplerates for 500MHz models. These won't provide the
200MHz value, because it cannot result from the device's base clock
and an integer divider. Needs to be 250MHz instead. This is untested,
needs to get verified when a 500MHz model will be supported.

diff --git a/src/hardware/kingst-la2016/api.c b/src/hardware/kingst-la2016/api.c
index b31bbc81d9d26fb6fa9faf97ddb28717f2563e3d..02293eb470b8324ab4c7201ef227f79c5c52ca9c 100644 (file)
--- a/src/hardware/kingst-la2016/api.c
+++ b/src/hardware/kingst-la2016/api.c
@@ -77,15 +77,37 @@ static const char *channel_names[] = {
 };
 
 /*
- * The hardware uses a (model dependent) 100/200/500MHz base clock and
+ * The hardware uses a 100/200/500MHz base clock (model dependent) and
  * a 16bit divider (common across all models). The range from 10kHz to
  * 100/200/500MHz should be applicable to all devices. High rates may
  * suffer from coarse resolution (e.g. in the "500MHz div 2" case) and
- * may not provide the desired 1/2/5 steps. This is not an issue now,
- * the 500MHz model is not supported yet by this driver.
+ * may not provide the desired 1/2/5 steps. Fortunately this exclusively
+ * affects the 500MHz model where 250MHz is used instead of 200MHz and
+ * the 166MHz and 125MHz rates are not presented to users. Deep memory
+ * of these models and hardware compression reduce the necessity to let
+ * users pick from a huge list of possible rates.
+ *
  */
 
-static const uint64_t samplerates_la2016[] = {
+static const uint64_t rates_500mhz[] = {
+       SR_KHZ(10),
+       SR_KHZ(20),
+       SR_KHZ(50),
+       SR_KHZ(100),
+       SR_KHZ(200),
+       SR_KHZ(500),
+       SR_MHZ(1),
+       SR_MHZ(2),
+       SR_MHZ(5),
+       SR_MHZ(10),
+       SR_MHZ(20),
+       SR_MHZ(50),
+       SR_MHZ(100),
+       SR_MHZ(250),
+       SR_MHZ(500),
+};
+
+static const uint64_t rates_200mhz[] = {
        SR_KHZ(10),
        SR_KHZ(20),
        SR_KHZ(50),
@@ -94,9 +116,7 @@ static const uint64_t samplerates_la2016[] = {
        SR_KHZ(500),
        SR_MHZ(1),
        SR_MHZ(2),
-       SR_MHZ(4),
        SR_MHZ(5),
-       SR_MHZ(8),
        SR_MHZ(10),
        SR_MHZ(20),
        SR_MHZ(50),
@@ -104,7 +124,7 @@ static const uint64_t samplerates_la2016[] = {
        SR_MHZ(200),
 };
 
-static const uint64_t samplerates_la1016[] = {
+static const uint64_t rates_100mhz[] = {
        SR_KHZ(10),
        SR_KHZ(20),
        SR_KHZ(50),
@@ -113,9 +133,7 @@ static const uint64_t samplerates_la1016[] = {
        SR_KHZ(500),
        SR_MHZ(1),
        SR_MHZ(2),
-       SR_MHZ(4),
        SR_MHZ(5),
-       SR_MHZ(8),
        SR_MHZ(10),
        SR_MHZ(20),
        SR_MHZ(50),
@@ -570,11 +588,12 @@ static int config_list(uint32_t key, GVariant **data,
        case SR_CONF_SAMPLERATE:
                if (!sdi)
                        return SR_ERR_ARG;
-               if (devc->max_samplerate == SR_MHZ(200)) {
-                       *data = std_gvar_samplerates(ARRAY_AND_SIZE(samplerates_la2016));
-               } else {
-                       *data = std_gvar_samplerates(ARRAY_AND_SIZE(samplerates_la1016));
-               }
+               if (devc->max_samplerate == SR_MHZ(500))
+                       *data = std_gvar_samplerates(ARRAY_AND_SIZE(rates_500mhz));
+               else if (devc->max_samplerate == SR_MHZ(200))
+                       *data = std_gvar_samplerates(ARRAY_AND_SIZE(rates_200mhz));
+               else
+                       *data = std_gvar_samplerates(ARRAY_AND_SIZE(rates_100mhz));
                break;
        case SR_CONF_LIMIT_SAMPLES:
                *data = std_gvar_tuple_u64(LA2016_NUM_SAMPLES_MIN,