2017-07-05 20:50 GMT+09:00 Kunihiko Hayashi [off-list ref]:
+
+#define TMOD 0x0928
+#define TMOD_MASK GENMASK(9, 0)
+
[ snip ]
+
+ /*
+ * The bit[8:0] of TMOD register represents 2's complement value
+ * of temperature in Celsius. Since bit8 of TMOD shows a sign bit,
+ * 32bit temperature value is obtained by sign extension.
+ */
Apparently, this comment does not match your code:
#define TMOD_MASK GENMASK(9, 0)
TMOD_MASK is indicating bit[9:0].
Digging into the patch history, now I understood what happened.
In v1, you described
#define TMOD_MASK 0x1ff
This was correct.
In v2, you converted it into
#define TMOD_MASK GENMASK(9, 0)
This was misconversion. It should be GENMASK(8, 0)
Anyway, TMOD_MASK is not used any more.
+ *out_temp = sign_extend32(temp, 8) * 1000;
Why magic number here?
/* MSB of the TMOD field is a sign bit */
*out_temp = sign_extend32(temp, TMOD_WIDTH) * 1000;
--
Best Regards
Masahiro Yamada