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. > Best regards, > Krzysztof
