Could you elaborate on the being privileged part i am new to this and don't know a lot. As i know the old drivers have been made for the 3.3 kernel and didn't use device tree overlays. I was thinking that since the function calls are reallly standard (iowirte16 and ioremap etc) that the only changes would be done to the values of pinmuxing themselves. I would just like to know what exactly i would have to change. If you want i can send you the hole code pertaining to the sensors. As far as i can see this SPI driver they made is actually handling the adding of multiple spi devices and writing and reading to them but somewhere they also use a header file from <linux/spi/spi.h> which makes me think that there is another driver that handles the communication itself (timing, sending receiving data etc). Am i wrong in thinking this? Please tell if it is not too much trouble and sorry if this is too nooby :-) .
2014-08-27 1:45 GMT+02:00 Sungjin Chun <[email protected]>: > As far as I know you have to be in the priviledged mode to change mux > value of pins (or you can use PRU to do this) which means > you have to write kernel module like this ( > https://github.com/chunsj/nxctrl/blob/master/nxpmx/nxpmx.c). > > > On Wed, Aug 27, 2014 at 12:40 AM, Cristian Mitu <[email protected]> > wrote: > >> Hello guys, >> >> >> I have a pig problem concerning a driver used for communicating with some >> MEMS components via SPI. The driver was developed for a Gumstix platform >> with OMAP34... processor running a 3.3 kernel. The driver muxes the pins >> using "iowrite16" functions. Some sample code can be seen below: >> >> ###Mux values sample : >> #define SPI_OE_MUX_OFFSET (0x48002A1A - OMAP34XX_PADCONF_START) >> #define SPI_CLK_MUX_OFFSET (0x480021C8 - OMAP34XX_PADCONF_START) >> ................. >> ###### >> >> ### Pin mode sample: >> #define OE_ENABLE_MUX 0x010C /* IEN | PTD | EN | M4 */ >> #define SPI_ENABLE_MUX 0x0100 /* IEN | PTD | DIS | M0 */ >> ###### >> >> >> // Multiplexing the pins code sample: >> base = ioremap(OMAP34XX_PADCONF_START, OMAP34XX_PADCONF_SIZE); >> >> if (!base) >> return -ENOMEM; >> >> old_spi_mux.oe_offset = ioread16(base + SPI_OE_MUX_OFFSET); >> iowrite16(OE_ENABLE_MUX, base + SPI_OE_MUX_OFFSET); >> ###### >> >> Now i understand how the offsets are calculated and how the I/O memory >> is beeing used. What i want to know is if i can reuse this code for the >> BeagleBone Black ( of course i know that i have to modify the mux values >> and pin modes to match to the BBB). My BBB is running a 3.8 kernel and as i >> know there is the major change with switching to the Device Tree system. >> >> Also if i use this method will i still need to write a device tree >> overlay setting the pins up there or is this done directly by using this >> code ( i feel this is a stupid question seeing as the DT is used >> specifically for setting up the pins so this code should do that instead >> but asking just so i know for sure). I thank you in advance for the >> response. >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> >> For more options, visit https://groups.google.com/d/optout. >> > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to a topic in the > Google Groups "BeagleBoard" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/beagleboard/H2-Xgjkgnbc/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
