在引擎盖下面,libgpiod打开内核为行提供的fd,然后调用ioctl(fd,GPIO_V2_LINE_SET_VALUES_IOCTL, ...)。我的问题是:ioctl()调用在理论上是否一般是阻塞的?例如,首先请求行也涉及到芯片fd上的ioctl()。I2Cioctl()s呢? 如果它是阻塞的,是行结构(line-&g ...
Wrote lgLineInfoFlags method to return string from bits Added lgGpioGetMode uses lgLineInfoFlags method Added lgGpioSetUser method Wrote lgGPIOUser structure Added lgTxBusy Added LG_TX_PWM Added LG_TX_WAVE Added LG_LOW Added LG_HIGH
gpioioctl/gpio.go Outdated Show resolved gpioioctl/gpio.go Outdated Show resolved Fix possible out of bounds error. 9d985ec maruel reviewed Nov 24, 2024 View reviewed changes Member maruel left a comment Thanks again! View details maruel merged commit 63e6b8c into periph:main Nov 24...
speed = MS_GPIO_SPEED_HIGH; ms_io_ioctl(fd_ds1, MS_GPIO_CMD_SET_PARAM, ¶m); ms_io_ioctl(fd_ds0, MS_GPIO_CMD_SET_PARAM, ¶m); param.mode = MS_GPIO_MODE_INPUT; param.pull = MS_GPIO_PULL_UP; param.speed = MS_GPIO_SPEED_HIGH; ms_io_ioctl(fd_key1, MS_GPIO_CMD_...
LOG(Error) << "Unable to re-init output " << line->DescribeShort(); return; } if (Chip->GetLabel() == "mcp23017" || Chip->GetLabel() == "mcp23008") { if (!FlushMcp23xState(line)) { LOG(Error) << "Unable to re-init output " << line->DescribeShort(); return; } }sik...
743 743 spidev_set(fd, SPI_IOC_RD_BITS_PER_WORD, &config.spi.bits_per_word, "spi bits per word"); 744 - //spidev_set(fd, SPI_IOC_RD_MODE, &config.spi.cs_change, "spi mode"); 745 744 746 745 if (ioctl(fd, SPI_IOC_MESSAGE(msg->num_xfers), msg->xfers) < 0) ...
Via sysfs, GPIOs could be read/written using the value file. For GPIO character devices, theGPIOHANDLE_GET_LINE_VALUES_IOCTLandGPIOHANDLE_SET_LINE_VALUES_IOCTLmay be used to get/set the state of one or more offsets within the chip. ...
if (lseek(fd, 0, SEEK_SET) == -1) { perror("lseek"); return -1; } Reacting on GPIO input interruptFunction poll can be used before function read to react and read values from the GPIO only on interrupts.struct pollfd fds[1]; fds[0].fd = fd; fds[0].events = POLLPRI; if ...
> Your case is not possible - CPU1 would see the value 1 set by CPU0 in the > read() and so NOK. Its xchg() would fail as it compares against 0 > and that also sees the 1 and so fails. > > What am I missing? Barriers? That's what documentation says about xchg().https:...
> static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata, > unsigned int version) > { > int abiv = atomic_cmpxchg(&cdata->watch_abi_version, 0, version); > > if (abiv == version) > return 0; > > return abiv; ...