> On Fri, 9 Jun 2017 11:30:00 +0200 > Lorenzo Bianconi <lorenzo.bianconi83@xxxxxxxxx> wrote: > >> Hi all, >> >> I started working on supporting spi-3wire mode in some STM MEMs >> drivers and I am facing a tricky issue. Let's consider the driver for >> LSM303AGR accel device >> (http://www.st.com/resource/en/datasheet/lsm303agr.pdf). The sensor is >> configured by default in spi 4 wire mode (BIT 0 in register 0x23) but >> the package does not export the MISO line for accelerometer. The only >> way to support spi is to enable 3-wire at bootstrap. I am wondering >> how to figure out the correct register address since it is not >> possible to read the device whoami. The only way that come up to my >> mind is to add a lookup table in st_accel_spi.c based on >> spi_device_id. Is there something better? Or should I just remove the >> spi support for LSM303AGR? Thanks >> >> Regards, >> Lorenzo >> > > Hi Lorenzo, > Hi Jonathan, > Look up table is probably the best option when a device only supports > 3 wire mode. > > However, don't we need DT of ACPI to provide info on whether a 3 wire > bus is being used? If so can we query it from the spi core? > Right, the user has to request the 3-wire mode using the standard spi-3wire property. > Jonathan Regards, Lorenzo -- UNIX is Sexy: who | grep -i blonde | talk; cd ~; wine; talk; touch; unzip; touch; strip; gasp; finger; gasp; mount; fsck; more; yes; gasp; umount; make clean; sleep -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
