kingst-la2016: rework acquisition limits, improve CLI use

[libsigrok.git] / src / hardware / kingst-la2016 / protocol.c

diff --git a/src/hardware/kingst-la2016/protocol.c b/src/hardware/kingst-la2016/protocol.c
index 102c5cc4b5da87ff16e44c69d13819d9453730fe..9d60beb105ec2e475230be8e6c913200df7d9b6d 100644 (file)
--- a/src/hardware/kingst-la2016/protocol.c
+++ b/src/hardware/kingst-la2016/protocol.c
@@ -615,7 +615,7 @@ static int set_trigger_config(const struct sr_dev_inst *sdi)
 static int set_sample_config(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
-       double clock_divisor;
+       uint64_t min_samplerate, eff_samplerate;
        uint16_t divider_u16;
        uint64_t limit_samples;
        uint64_t pre_trigger_samples;
@@ -631,17 +631,15 @@ static int set_sample_config(const struct sr_dev_inst *sdi)
                        devc->cur_samplerate);
                return SR_ERR_ARG;
        }
-       if (devc->cur_samplerate < MIN_SAMPLE_RATE_LA2016) {
+       min_samplerate = devc->model->samplerate;
+       min_samplerate /= 65536;
+       if (devc->cur_samplerate < min_samplerate) {
                sr_err("Too low a sample rate: %" PRIu64 ".",
                        devc->cur_samplerate);
                return SR_ERR_ARG;
        }
-
-       clock_divisor = devc->model->samplerate / (double)devc->cur_samplerate;
-       if (clock_divisor > 65535)
-               return SR_ERR_ARG;
-       divider_u16 = (uint16_t)(clock_divisor + 0.5);
-       devc->cur_samplerate = devc->model->samplerate / divider_u16;
+       divider_u16 = devc->model->samplerate / devc->cur_samplerate;
+       eff_samplerate = devc->model->samplerate / divider_u16;
 
        ret = sr_sw_limits_get_remain(&devc->sw_limits,
                &limit_samples, NULL, NULL, NULL);
@@ -650,12 +648,14 @@ static int set_sample_config(const struct sr_dev_inst *sdi)
                return ret;
        }
        if (limit_samples > LA2016_NUM_SAMPLES_MAX) {
-               sr_err("Too high a sample depth: %" PRIu64 ".", limit_samples);
-               return SR_ERR_ARG;
+               sr_warn("Too high a sample depth: %" PRIu64 ", capping.",
+                       limit_samples);
+               limit_samples = LA2016_NUM_SAMPLES_MAX;
        }
-       if (limit_samples < LA2016_NUM_SAMPLES_MIN) {
-               sr_err("Too low a sample depth: %" PRIu64 ".", limit_samples);
-               return SR_ERR_ARG;
+       if (limit_samples == 0) {
+               limit_samples = LA2016_NUM_SAMPLES_MAX;
+               sr_dbg("Passing %" PRIu64 " to HW for unlimited samples.",
+                       limit_samples);
        }
 
        /*
@@ -670,23 +670,36 @@ static int set_sample_config(const struct sr_dev_inst *sdi)
         * limit the amount of sample memory to use for pre-trigger
         * data. Only the upper 24 bits of that memory size spec get
         * communicated to the device (written to its FPGA register).
+        *
+        * TODO Determine whether the pre-trigger memory size gets
+        * specified in samples or in bytes. A previous implementation
+        * suggests bytes but this is suspicious when every other spec
+        * is in terms of samples.
         */
-       pre_trigger_samples = limit_samples * devc->capture_ratio / 100;
-       pre_trigger_memory = LA2016_PRE_MEM_LIMIT_BASE;
-       pre_trigger_memory *= devc->capture_ratio;
-       pre_trigger_memory /= 100;
+       if (devc->trigger_involved) {
+               pre_trigger_samples = limit_samples;
+               pre_trigger_samples *= devc->capture_ratio;
+               pre_trigger_samples /= 100;
+               pre_trigger_memory = devc->model->memory_bits;
+               pre_trigger_memory *= UINT64_C(1024 * 1024 * 1024);
+               pre_trigger_memory /= 8; /* devc->model->channel_count ? */
+               pre_trigger_memory *= devc->capture_ratio;
+               pre_trigger_memory /= 100;
+       } else {
+               sr_dbg("No trigger setup, skipping pre-trigger config.");
+               pre_trigger_samples = 1;
+               pre_trigger_memory = 0;
+       }
+       /* Ensure non-zero value after LSB shift out in HW reg. */
+       if (pre_trigger_memory < 0x100) {
+               pre_trigger_memory = 0x100;
+       }
 
        sr_dbg("Set sample config: %" PRIu64 "kHz, %" PRIu64 " samples.",
-               devc->cur_samplerate / 1000, limit_samples);
+               eff_samplerate / SR_KHZ(1), limit_samples);
        sr_dbg("Capture ratio %" PRIu64 "%%, count %" PRIu64 ", mem %" PRIu64 ".",
                devc->capture_ratio, pre_trigger_samples, pre_trigger_memory);
 
-       if (!devc->trigger_involved) {
-               sr_dbg("Voiding pre-trigger setup. No trigger involved.");
-               pre_trigger_samples = 1;
-               pre_trigger_memory = 0x100;
-       }
-
        /*
         * The acquisition configuration occupies a total of 16 bytes:
         * - A 34bit total samples count limit (up to 10 billions) that