On 07/30/13 04:39, Jonathan Clapson wrote: > Hey > > I'm trying to write a driver to interact with the mpu6000 imu sensor > on the raspberry pi. > I've modified the mpu6050 i2c driver in the linux kernel to use the > mpu6000's spi interface. Calls of iio_trigger_alloc fail. I've added > some debugging info to industrialio-trigger.c and from this have > narrowed it down to the irq_alloc_descs function failing to allocate > any irq's. > > cat /proc/interrupts returns: > CPU0 > 3: 21114 ARMCTRL BCM2708 Timer Tick > 32: 986019 ARMCTRL dwc_otg, dwc_otg_pcd, dwc_otg_hcd:usb1 > 65: 7 ARMCTRL ARM Mailbox IRQ > 66: 1 ARMCTRL VCHIQ doorbell > 75: 1 ARMCTRL > 77: 6801 ARMCTRL bcm2708_sdhci (dma) > 80: 30 ARMCTRL bcm2708_spi.0 > 83: 20 ARMCTRL uart-pl011 > 84: 11002 ARMCTRL mmc0 > FIQ: usb_fiq > Err: 0 > > The call to irq_alloc_descs seems to be trying to allocate *any* two > consecutive irq's (two being the value of > CONFIG_IIO_CONSUMERS_PER_TRIGGER), the above i believe shows that this > should be possible? > > Any idea's why irq_alloc_descs is failing? It has been a while since I last came across anything similar but this is probably due to the underlying raspberry pi kernel restricting your available interrupts. In at least some boards it is still necessary to explicitly allocate a few more in the board config file or equivalent. > > Thanks > -- > 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 > -- 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
