On 2/14/21 4:49 AM, Jesse T wrote:
Awesome, thanks! I must have forgotten how twos complement works for a
sec...
On Sat, Feb 13, 2021 at 10:17 PM Giulio Benetti <
giulio.bene...@benettiengineering.com> wrote:
Hi Jesse,
Il giorno 14 feb 2021, alle ore 03:58, Jesse T <mr.bossman...@gmail.com>
ha scritto:
This looks good to me, and helps beginners like me. As for the function
itself, i have 2 concerns: If it does return a negative value why is it
unsigned, if it is in fact signed that a clock above 2.2Ghz is a negative
number.
I was worried too at first sight but if you try to check negative numbers
you see that -1 is 0xFFFFFFFF so in the worst case you only loose 4095
numbers from the maximum, try to check with hex calculator. And that is the
trick.
As for the IS_ERR_VALUE macro there still is a chance that it will error
if the clock just so happens to be 2^31 through 2^31 + number of err
values.
This is answered from above and IS_ERR_VALUE is a very contracted macro
that basically let you to keep value NOT valid if (0 > value > 4095).
Just voicing my concerns i assume as i learn more about uboot,
linux,rtos's and different programs there will be minor issues like this.
Sure, no problem :-)
Giulio
On Sat, Feb 13, 2021 at 9:17 PM Giulio Benetti <
giulio.bene...@benettiengineering.com> wrote:
Improve clk_get_rate() @return documentation that otherwise is a bit
ambiguous. At the moment I expect to return 0 as error since the return
type is 'ulong', instead the function really returns negative value in
case the corresponding function pointer is null and returns 0 if the clock
is invalid.
Signed-off-by: Giulio Benetti <giulio.bene...@benettiengineering.com>
---
V1->V2:
* previous comment was wrong, this function returns negative value, so
let's
improve it's @return documentation as suggested by Simon Glass
---
include/clk.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/clk.h b/include/clk.h
index ca6b85fa6f..5a8c7244d0 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -344,7 +344,8 @@ int clk_free(struct clk *clk);
*
* @clk: A clock struct that was previously successfully requested
by
* clk_request/get_by_*().
- * @return clock rate in Hz, or -ve error code.
+ * @return clock rate in Hz on success, 0 for invalid clock, or -ve
error code
+ * for other errors.
*/
ulong clk_get_rate(struct clk *clk);
--
2.25.1
Cc: Lukasz Majewski <lu...@denx.de>
Lukasz is maintainer for CLOCK.
