hantek-dso: dso2250: Support sample rates correctly.

[libsigrok.git] / src / hardware / hantek-dso / protocol.c

diff --git a/src/hardware/hantek-dso/protocol.c b/src/hardware/hantek-dso/protocol.c
index 831e357f0857e93ff0453a95165585022192a5d8..a1413b8f09fe19801ef0c494013e98246f107bcf 100644 (file)
--- a/src/hardware/hantek-dso/protocol.c
+++ b/src/hardware/hantek-dso/protocol.c
@@ -303,41 +303,32 @@ static int dso2250_set_trigger_samplerate(const struct sr_dev_inst *sdi)
 
        memset(cmdstring, 0, sizeof(cmdstring));
        cmdstring[0] = CMD_2250_SET_SAMPLERATE;
-       /* Timebase fast */
-       sr_dbg("Time base index: %d.", devc->timebase);
+       sr_dbg("Sample rate: %u", devc->samplerate);
        base = 100e6;
-       if (devc->timebase < TIME_40us) {
-               if (devc->framesize != FRAMESIZE_SMALL) {
-                       sr_err("Timebase < 40us only supported with 10K buffer.");
-                       return SR_ERR_ARG;
-               }
-
-               /* Fast mode on */
-               base = 200e6;
-               cmdstring[2] |= 1;
+       if (devc->samplerate > base) {
+               /* Timebase fast */
+               sr_err("Sample rate > 100MHz not yet supported.");
+               return SR_ERR_ARG;
        }
 
-       /* Downsampling on */
-       cmdstring[2] |= 2;
-       /* Downsampler = 1comp((Base / Samplerate) - 2)
-        *  Base == 100Msa resp. 200MSa
-        *
-        * Example for 500kSa/s:
-        *  100e6 / 500e3 => 200
-        *  200 - 2 => 198
-        *  1comp(198) => ff39 */
-
-       tmp = base * timebase_to_time(devc->timebase);
-       tmp = 200;
-       if (tmp < 0)
-               return SR_ERR_ARG;
-       tmp -= 2;
-       if (tmp < 0)
-               return SR_ERR_ARG;
-       tmp = ~tmp;
-       sr_dbg("sample rate value: 0x%x.", tmp & 0xffff);
-       cmdstring[4] = (tmp >> 0) & 0xff;
-       cmdstring[5] = (tmp >> 8) & 0xff;
+       tmp = base / devc->samplerate;
+       sr_dbg("sample rate value: %d.", devc->samplerate);
+       if (tmp) {
+               /* Downsampling on */
+               cmdstring[2] |= 2;
+               /* Downsampler = 1comp((Base / Samplerate) - 2)
+                *  Base == 100Msa resp. 200MSa
+                *
+                * Example for 500kSa/s:
+                *  100e6 / 500e3 => 200
+                *  200 - 2 => 198
+                *  1comp(198) => ff39 */
+               tmp -= 2;
+               tmp = ~tmp;
+               sr_dbg("down sampler value: 0x%x.", tmp & 0xffff);
+               cmdstring[4] = (tmp >> 0) & 0xff;
+               cmdstring[5] = (tmp >> 8) & 0xff;
+       }
 
        if (send_begin(sdi) != SR_OK)
                return SR_ERR;
@@ -375,7 +366,6 @@ static int dso2250_set_trigger_samplerate(const struct sr_dev_inst *sdi)
        cmdstring[0] = CMD_2250_SET_TRIGGERPOS_AND_BUFFER;
 
        /* TODO for big buffer */
-       /* TODO */
        sr_dbg("Trigger position: %3.2f.", devc->triggerposition);
 //     tmp = 0x77fff + 0x8000 * devc->triggerposition;
 //     cmdstring[6] = tmp & 0xff;
@@ -404,7 +394,7 @@ static int dso2250_set_trigger_samplerate(const struct sr_dev_inst *sdi)
        return SR_OK;
 }
 
-static int dso_set_trigger_samplerate(const struct sr_dev_inst *sdi)
+int dso_set_trigger_samplerate(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
        struct sr_usb_dev_inst *usb;