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, 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? Jonathan -- 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
