On Thu, May 17, 2018 at 1:11 AM, Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > On Wed, May 16, 2018 at 11:43 PM, Dan Murphy <dmurphy@xxxxxx> wrote: >> On 05/15/2018 05:24 PM, Andy Shevchenko wrote: >>> On Wed, May 16, 2018 at 1:08 AM, Dan Murphy <dmurphy@xxxxxx> wrote: >>>> On 05/15/2018 04:56 PM, Andy Shevchenko wrote: >>>>>> +static const struct lm3601x_max_timeouts strobe_timeouts[] = { >>>>>> + { 40000, 0x00 }, >>>>>> + { 80000, 0x01 }, >>>>>> + { 120000, 0x02 }, >>>>>> + { 160000, 0x03 }, >>>>>> + { 200000, 0x04 }, >>>>>> + { 240000, 0x05 }, >>>>>> + { 280000, 0x06 }, >>>>>> + { 320000, 0x07 }, >>>>>> + { 360000, 0x08 }, >>>>>> + { 400000, 0x09 }, >>>>>> + { 600000, 0x0a }, >>>>>> + { 800000, 0x0b }, >>>>>> + { 1000000, 0x0c }, >>>>>> + { 1200000, 0x0d }, >>>>>> + { 1400000, 0x0e }, >>>>>> + { 1600000, 0x0f }, >>> if (x < 9) >>> strobe_timeout = (x + 1) * 40 * MSECS_IN_SEC; >>> else >>> strobe_timeout = (x - 7) * 200 * MSECS_IN_SEC; >> >> Not sure if this will produce the register value I am looking for. I have to run through the >> algorithim. The idea is to take in the timeout and get the reg value to program. >> >> If it yields the expected output, or with a modified equation, then I can pull it in. > > So, you need a reversed calculus in this case. > > u8 regval; > > /* To make it in range... */ > timeout = clamp_val(timeout, 40000, 1600000); > /* ...other possibility to issue an error */ > > if (timeout >= 400000) > regval = timeout / 200000 + 0x07; > else > regval = timeout / 40000 - 0x01; Forgot to mention that there are also three approaches (considering division here): - round up - round down - round to closest > > In any case, please double check it gives a correct values. -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html