asix-sigma: prepare configuration re-use across sigrok sessions

[libsigrok.git] / src / hardware / asix-sigma / protocol.c

diff --git a/src/hardware/asix-sigma/protocol.c b/src/hardware/asix-sigma/protocol.c
index dd74ec98cc156a07af0532a6a49ef1cb0a3a8165..b1af2e5a2f0efda93f4d412fb17504e72d6ac706 100644 (file)
--- a/src/hardware/asix-sigma/protocol.c
+++ b/src/hardware/asix-sigma/protocol.c
@@ -1014,11 +1014,51 @@ SR_PRIV int sigma_normalize_samplerate(uint64_t want_rate, uint64_t *have_rate)
        return SR_ERR_ARG;
 }
 
-SR_PRIV uint64_t sigma_get_samplerate(const struct sr_dev_inst *sdi)
+/* Gets called at probe time. Can seed software settings from hardware state. */
+SR_PRIV int sigma_fetch_hw_config(const struct sr_dev_inst *sdi)
 {
-       /* TODO Retrieve value from hardware. */
+       struct dev_context *devc;
+       int ret;
+       uint8_t regaddr, regval;
+
+       devc = sdi->priv;
+       if (!devc)
+               return SR_ERR_ARG;
+
+       /* Seed configuration values from defaults. */
+       devc->firmware_idx = SIGMA_FW_NONE;
+       devc->clock.samplerate = samplerates[0];
+
+       /* TODO
+        * Ideally the device driver could retrieve recently stored
+        * details from hardware registers, thus re-use user specified
+        * configuration values across sigrok sessions. Which could
+        * avoid repeated expensive though unnecessary firmware uploads,
+        * improve performance and usability. Unfortunately it appears
+        * that the registers range which is documented as available for
+        * application use keeps providing 0xff data content. At least
+        * with the netlist version which ships with sigrok. The same
+        * was observed with unused registers in the first page.
+        */
+       return SR_ERR_NA;
+
+       /* This is for research, currently does not work yet. */
+       ret = sigma_check_open(sdi);
+       regaddr = 16;
+       regaddr = 14;
+       ret = sigma_set_register(devc, regaddr, 'F');
+       ret = sigma_get_register(devc, regaddr, &regval);
+       sr_warn("%s() reg[%u] val[%u] rc[%d]", __func__, regaddr, regval, ret);
+       ret = sigma_check_close(devc);
+       return ret;
+}
+
+/* Gets called after successful (volatile) hardware configuration. */
+SR_PRIV int sigma_store_hw_config(const struct sr_dev_inst *sdi)
+{
+       /* TODO See above, registers seem to not hold written data. */
        (void)sdi;
-       return samplerates[0];
+       return SR_ERR_NA;
 }
 
 SR_PRIV int sigma_set_samplerate(const struct sr_dev_inst *sdi)
@@ -1064,6 +1104,14 @@ SR_PRIV int sigma_set_samplerate(const struct sr_dev_inst *sdi)
                devc->samples_per_event = 16 / devc->num_channels;
        }
 
+       /*
+        * Store the firmware type and most recently configured samplerate
+        * in hardware, such that subsequent sessions can start from there.
+        * This is a "best effort" approach. Failure is non-fatal.
+        */
+       if (ret == SR_OK)
+               (void)sigma_store_hw_config(sdi);
+
        return ret;
 }