On 12/30/20 2:41 PM, Jonathan Cameron wrote:
On Thu, 24 Dec 2020 03:19:21 +0000
Jyoti Bhayana <jbhay...@google.com> wrote:
+ /*
+ * The seconds field in the sensor interval in SCMI is 16 bits long
+ * Therefore seconds = 1/Hz <= 0xFFFF. As floating point calculations
are
+ * discouraged in the kernel driver code, to calculate the scale factor
(sf)
+ * (1* 1000000 * sf)/uHz <= 0xFFFF. Therefore, sf <= (uHz *
0xFFFF)/1000000
+ * To calculate the multiplier,we convert the sf into char string and
+ * count the number of characters
+ */
+
+ mult = scnprintf(buf, 32, "%llu", ((u64)uHz * 0xFFFF) / UHZ_PER_HZ) - 1;
use sizeof(buf) instead of having 32 again.
Since this is just interested in the number of characters and not the
string itself I believe it is possible to just call sprintf with NULL
instead of a buffer. It will then still return the number of characters,
but not print anything.
But maybe providing a ilog10() helper is the better approach.
