I have installed uClinux with microblaze 3.14.0 kernel in the Avnet LX9 microboard. I am using DS18B20 1-wire temperature sensor from Maxim and trying to communicate through a IP-Core xps-gpio. Following Maxim datasheet recommendations I have established the next UCF configuration for the data pin of DS18B20.
# 1-wire interface. # External pull-up is 680 Ohms requiring approximately 5mA to drive the line Low. NET axi_gpio_0_GPIO_IO_pin LOC = "E18" | IOSTANDARD = LVCMOS33 | SLEW = SLOW | DRIVE = 8; In the kernel configuration I have added the driver for "1-wire Bus Masters -> GPIO 1-wire busmaster" and "1-wire Slaves -> Thermal family implementation”. During the kernel loading I also read "Driver for 1-wire Dallas network protocol" indicating that the driver has been loaded.
The DS18B20 driver scans the 1-wire bus every 10 seconds for new hardware connected to the bus and adds a new directory for each new device in the directory “/sys/bus/w1/devices/w1 bus master”. The problem is that i can not find the device under the last directory. I tried the same process under the Zedboard and I detected the sensor without problems. I think is because the arm of Zynq has an external GPIO that allows the driver to detect the sensor.
Any suggestion to make the driver working under the LX9 microboard?