mjb/altos/src/stmf0/ao_adc_fast.h, branch tmgps

altos/stmf0: Use double buffering for ChaosKey

2018-01-08T05:44:39+00:00

This improves the USB performance of ChaosKey so that it doesn't NAK during data transfers at all. Signed-off-by: Keith Packard

altos/arm: Align data so that gcc 5.4 doesn't do byte-accesses. Add -Wcast-align

2016-12-18T05:04:33+00:00

Gcc 5.4.1 tracks alignment of data through assignments, so that a uint32_t pointer which comes from byte-aligned uint8_t data: extern uint8_t foo[]; uint32_t *q = (void *) foo; Fetches and stores through this pointer are done bytewise. This is slow (meh), but if q references a device register, things to bad very quickly. This patch works around this bug in the compiler by adding __attribute__((aligned(4))) tags to some variables, or changing them from uint8_t to uint32_t. Places doing this will now be caught as I've added -Wcast-align to the compiler flags. That required adding (void *) casts, after the relevant code was checked to make sure the compiler could tell that the addresses were aligned. Signed-off-by: Keith Packard

Switch from GPLv2 to GPLv2+

2016-07-12T22:41:41+00:00

Signed-off-by: Keith Packard

altos/stmf0: Have fast ADC ring buffer code use wrap-around

2015-03-20T22:09:20+00:00

Instead of requiring that the whole set of returned values fit precisely in the ring, allow for wrap-around so that we can fetch an odd number of ADC values. The previous version required that the fetch amount always be a factor of the ADC buffer size. Signed-off-by: Keith Packard

altos/stmf0: Fix fast ADC interface

2015-03-01T00:10:10+00:00

This was configuring the hardware wrong, and wasn't keeping the output ring full. Signed-off-by: Keith Packard

altos/stmf0: Re-implement fast ADC code for stmf0

2015-01-28T04:41:15+00:00

This creates a ring buffer for ADC data so that ADC fetching can run in parallel with other activities. Signed-off-by: Keith Packard

altos/stmf0: Add ADC and DMA APIs

2015-01-27T06:14:57+00:00

The ADC api is what USBtrng wants; a way to repeatedly read a single ADC input as fast as possible. Signed-off-by: Keith Packard