hi: 2011/8/26 OrazioPirataDelloSpazio (Lorenzo) <ziducaixao@xxxxxxxxxxxxx>: > Hi there, > I have a motherbord (VIA EPIA LT) with a digital I/O port composed by 4 > GPI and 4 GPO (chip: SMSC SCH3114). > > I want to provide voltage to GPO and read the input value of GPI with a > software. > > Using the generic gpio kernel module, I tried to export pins without > success : > > echo N > /sys/class/gpio/export > write error : invalid argument > > I tried for several values of N (from 1 to 1000 !) then I gave up > thinking I would have needed some information from the hardware producer. > Now I have got this information that is the following offsets and addresses. > > How can I use these registers to fix the export problem or alternatively > how to write a simple userspace C program to read and write these GPIO? > > I read gpio.txt but I'm still confused on how to pass from GPIO numbers > to registers. > > Thanks > > > Lorenzo > > > #define sGPIOBaseAddr 0A00 > #define GPI1_CTRL_REG 0x6E > #define GPI2_CTRL_REG 0x6F > #define GPI3_CTRL_REG 0x72 > #define GPI4_CTRL_REG 0x73 > #define GPO1_CTRL_REG 0x2C > #define GPO2_CTRL_REG 0x2D > #define GPO3_CTRL_REG 0x35 > #define GPO4_CTRL_REG 0x36 > does the base address of gpio in kernel you use is the same or you have modified for your board? BR _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
