Use driver name as the log prefix in standard functions

[libsigrok.git] / src / analog.c

diff --git a/src/analog.c b/src/analog.c
index 7c0dde1be5e9265c713371c78819b09f1189197b..7343b481e610d409d51bb45dd5f2be1a31138c77 100644 (file)
--- a/src/analog.c
+++ b/src/analog.c
@@ -444,6 +444,8 @@ SR_API int sr_rational_eq(const struct sr_rational *a, const struct sr_rational
  * otherwise. If the resulting nominator/denominator are relatively prime,
  * this may not be possible.
  *
+ * It is save to use the same variable for result and input values
+ *
  * @retval SR_OK Success.
  * @retval SR_ERR_ARG Resulting value to large
  *
@@ -506,4 +508,45 @@ SR_API int sr_rational_mult(struct sr_rational *res, const struct sr_rational *a
 #endif
 }
 
+/**
+ * Divide rational a by rational b
+ *
+ * @param[in] num numerator
+ * @param[in] div divisor
+ * @param[out] res Result
+ *
+ * The resulting nominator/denominator are reduced if the result would not fit
+ * otherwise. If the resulting nominator/denominator are relatively prime,
+ * this may not be possible.
+ *
+ * It is save to use the same variable for result and input values
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR_ARG Division by zero
+ * @retval SR_ERR_ARG Denominator of divisor to large
+ * @retval SR_ERR_ARG Resulting value to large
+ *
+ * @since 0.5.0
+ */
+SR_API int sr_rational_div(struct sr_rational *res, const struct sr_rational *num,
+       const struct sr_rational *div)
+{
+       struct sr_rational t;
+
+       if (div->q > INT64_MAX)
+               return SR_ERR_ARG;
+       if (div->p == 0)
+               return SR_ERR_ARG;
+
+       if (div->p > 0) {
+               t.p = div->q;
+               t.q = div->p;
+       } else {
+               t.p = -div->q;
+               t.q = -div->p;
+       }
+
+       return sr_rational_mult(res, num, &t);
+}
+
 /** @} */