On 25/06/2026 15:40, Sunyun Yang wrote: > Sunyun Yang <[email protected]> 于2026年6月25日周四 21:26写道： >> >> Krzysztof Kozlowski <[email protected]> 于2026年6月25日周四 21:17写道： >>> >>> On 25/06/2026 15:14, Sunyun Yang wrote: >>>> Krzysztof Kozlowski <[email protected]> 于2026年6月25日周四 20:54写道： >>>>> >>>>> On 08/05/2026 15:40, [email protected] wrote: >>>>>> + >>>>>> +static void lt9611c_reset(struct lt9611c *lt9611c) >>>>>> +{ >>>>>> + gpiod_set_value_cansleep(lt9611c->reset_gpio, 1); >>>>>> + msleep(20); >>>>>> + >>>>>> + gpiod_set_value_cansleep(lt9611c->reset_gpio, 0); >>>>>> + msleep(20); >>>>>> + >>>>>> + gpiod_set_value_cansleep(lt9611c->reset_gpio, 1); >>>>> >>>>> This is just plain wrong. Why do you assert, then de-assert and then >>>>> finally assert AGAIN the reset leaving the device in powerdown stage? >>>>> >>>> I am using software to emulate the hardware RESET button on our EVB. >>>> When the hardware RESET button is pressed while our chip is running, >>>> the signal level changes from HIGH to LOW and then back to HIGH. >>>> >>>> Of course, we can also use the following: >>>> static void lt9611c_reset(struct lt9611c *lt9611c) >>>> { >>>> gpiod_set_value_cansleep(lt9611c->reset_gpio, 0); >>>> msleep(50); >>>> gpiod_set_value_cansleep(lt9611c->reset_gpio, 1); >>>> msleep(20); >>>> } >>> >>> Makes no sense either and you just did not get the point and did not >>> answer my question. I asked WHY you leave asserted. Answer "we emulate" >>> is just plain wrong. >>> >>> So again please answer: >>> >>> Why do you leave device with reset asserted? >>> >> >> devicetree: reset-gpios = <&tlmm 128 GPIO_ACTIVE_HIGH>; >> >> GPIO_ACTIVE_HIGH: >> >> gpiod_set_value_cansleep(lt9611c->reset_gpio, 0); ------ reset pin >> is Low level : Clear the register configuration in the chip to stop >> the chip from working. >> >> gpiod_set_value_cansleep(lt9611c->reset_gpio, 1); ------ reset pin >> is high level: The chip resumes operation. >> >> > > Our purpose is: pull the level low to clear the register configuration > in the chip, and then pull it high to allow the MCU inside the chip to > re‑initialize the registers.
And you do completely opposite... so that confirms your code is just wrong. Best regards, Krzysztof
