kingst-la2016: rephrase manufacture date and device type support

[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 b5e70b3d7dcb646afa0d6498fe11c6b9095af09a..609c8aa20517e9d4741134f85cd54f41072ec229 100644 (file)
--- a/src/hardware/kingst-la2016/protocol.c
+++ b/src/hardware/kingst-la2016/protocol.c
@@ -1106,7 +1106,9 @@ SR_PRIV int la2016_init_device(const struct sr_dev_inst *sdi)
        struct dev_context *devc;
        uint16_t state;
        uint8_t buf[8];
-       int16_t purchase_date_bcd[2];
+       const uint8_t *rdptr;
+       uint8_t date_yy, date_mm;
+       uint8_t dinv_yy, dinv_mm;
        uint8_t magic;
        const char *bitstream_fn;
        int ret;
@@ -1114,20 +1116,24 @@ SR_PRIV int la2016_init_device(const struct sr_dev_inst *sdi)
        devc = sdi->priv;
 
        /*
-        * Four EEPROM bytes at offset 0x20 are purchase year and month
-        * in BCD format, with 16bit complemented checksum. For example
-        * 20 04 df fb translates to 2020-04. This can help identify the
-        * age of devices when unknown magic numbers are seen.
+        * Four EEPROM bytes at offset 0x20 are the manufacturing date,
+        * year and month in BCD format, followed by inverted values for
+        * consistency checks. For example bytes 20 04 df fb translate
+        * to 2020-04. This information can help identify the vintage of
+        * devices when unknown magic numbers are seen.
         */
-       if ((ret = ctrl_in(sdi, CMD_EEPROM, 0x20, 0, purchase_date_bcd, sizeof(purchase_date_bcd))) != SR_OK) {
-               sr_err("Cannot read purchase date in EEPROM.");
+       ret = ctrl_in(sdi, CMD_EEPROM, 0x20, 0, buf, 4 * sizeof(uint8_t));
+       if (ret != SR_OK) {
+               sr_err("Cannot read manufacture date in EEPROM.");
        } else {
-               sr_dbg("Purchase date: 20%02hx-%02hx.",
-                       (purchase_date_bcd[0]) & 0xff,
-                       (purchase_date_bcd[0] >> 8) & 0xff);
-               if (purchase_date_bcd[0] != (0x0ffff & ~purchase_date_bcd[1])) {
-                       sr_err("Purchase date fails checksum test.");
-               }
+               rdptr = &buf[0];
+               date_yy = read_u8_inc(&rdptr);
+               date_mm = read_u8_inc(&rdptr);
+               dinv_yy = read_u8_inc(&rdptr);
+               dinv_mm = read_u8_inc(&rdptr);
+               sr_info("Manufacture date: 20%02hx-%02hx.", date_yy, date_mm);
+               if ((date_mm ^ dinv_mm) != 0xff || (date_yy ^ dinv_yy) != 0xff)
+                       sr_warn("Manufacture date fails checksum test.");
        }
 
        /*
@@ -1172,17 +1178,18 @@ SR_PRIV int la2016_init_device(const struct sr_dev_inst *sdi)
                sr_err("Cannot read EEPROM device identifier bytes.");
                return ret;
        }
-
-       magic = 0;
-       if (buf[0] == (0xff & ~buf[1])) {
+       if ((buf[0] ^ buf[1]) == 0xff) {
                /* Primary copy of magic passes complement check. */
+               sr_dbg("Using primary copy of device type magic number.");
                magic = buf[0];
-       } else if (buf[4] == (0xff & ~buf[5])) {
+       } else if ((buf[4] ^ buf[5]) == 0xff) {
                /* Backup copy of magic passes complement check. */
                sr_dbg("Using backup copy of device type magic number.");
                magic = buf[4];
+       } else {
+               sr_err("Cannot find consistent device type identification.");
+               magic = 0;
        }
-
        sr_dbg("Device type: magic number is %hhu.", magic);
 
        /* Select the FPGA bitstream depending on the model. */