If a timer's channel was set with a really small realtive duration from
now, such that it would be missed (underflowed), the driver would stop
the timer, potentially causing missed ticks. It was stopped to ensure
that the channel's output-compare register could be set to the current
counter value, before re-enabling the timer's counter. This is a
condition that will ensure that the underflow won't happen again and the
interrupt will fire, at the cost of losing some ticks for very high
speed clocks.
This patch replaces the logic that stopped the timer. Instead it uses a
register provided by the timer hardware to trigger timer interrupts via
software.
The macros CONCAT(), MIN(), and MAX() are defined over and over again in
RIOT's code base. This de-duplicates the code by moving the macros to a
common place.
Allow two threads to share the same timer - provided they use distinct
sets of timer channels - without occasionally corrupting registers or
state flags.
These models have 256 kByte RAM, but the upper 64 kByte are used as CCM data RAM accessible at 0x1000:0000. The access to 0x2003:xxxx leads to a hard fault.
There are STM32 families where all models use only the Synopsys DWC2 USB OTG core while others completely use only the USB Device FS core. For these families then either the driver `drivers/usbdev_synopsys_dwc2` or the driver `cpu/stm32/periph/usbdev` is used depending on the respective family. However, the STM32 families F1 and L4 use both cores. The correct driver must therefore be selected depending on the CPU line or CPU model.
This splits up the clock configs.
It allows CPU_FAM based file sourcing and also common CPU_FAMs.
The dependancies are also included in wildcards would be used for the CPU_FAM macro.
This should be much more readable.
This also takes into account the HSE speeds in order to match the make/header resolution.
Some hidden symbols were added to make sorting many CPU_SERIES dependencies easier.
As implmented, dma_resume assumed that transfers widths were 1 byte and
that the memory address incrmenting was always on and periphial address
incrementing always off. This resulted in memory corruption anytime
these assumptions were not true and a dma was resumed. The DMA module
allows intitiating transfers that did not meet these assumption.
This patch adds proper handling inside dma_resume to safely resume any
transfer. Clearifications and errors are added/fixed in the module's
header file. Also, a few constants are removed from the gobal namespace.
As it was, the calculation of DMA2's IRQ number was inccrorect for some
STM families. The implmentation alocates streams numbers 0 to 7 for the
first DMA controller and 8 and up for the second DMA controller. This
offset of +8 was not accounted for when IRQ's of the second DMA
controller was calculated. This patch corrects this.
Use `DWC2_USB_OTG_FS_TOTAL_FIFO_SIZE` instead of `USB_OTG_FS_TOTAL_FIFO_SIZE` since the latter is only defined in the vendor headers for STM32 MCUs. The STM32-specific problem that `USB_OTG_FS_TOTAL_FIFO_SIZE` is not defined in the vendor headers for all STM32 families has therefore been moved from the driver to the STM32-specific USB device header.
There are two schemes for accessing the packet buffer area (PMA) from the CPU:
- 2 x 16 bit/word access scheme where two 16-bit half-words per word can be accessed. With this scheme the access can be half-word aligned and the PMA address offset corresponds therefore to the local USB IP address. The size of the PMA SRAM is usually 1024 byte.
- 1 x 16 bit/word access scheme where one 16-bit half word per word can be accessed. With this scheme the access can only be word-aligned and the PMA address offset to a half-word is therefore twice the local USB IP address. The size of the PMA SRAM is usually 512 byte.
Which access scheme is used depends on the STM32 model.
The addressing of the Packet buffer Memory Area (PMA) is done locally in the USB IP core in half-words with 16-bit. The `_ep_in_buf` and `_ep_out_buf` arrays which hold these USB IP local addresses in the PMA for initialized EPs therefore always use `uint16_t`.
If the MCU does not have an internal D+ pullup and there is no dedicated GPIO to simulate a USB disconnect, the D+ GPIO is temporarily configured as an output and pushed down to simulate a disconnect/connect cycle to allow the host to recognize the device. However, this requires an external pullup on D+ signal to work
If `RCC_CFGR_USBPRE` is defined, the USB device FS clock of 48 MHz is derived from the PLL clock. In this case the PLL clock must be configured and must be either 48 MHz or 72 MHz. If the PLL clock is 72 MHz it is pre-divided by 1.5, the PLL clock of 48 MHz is used directly.
For a number of STM32 MCUs with the USB-FS device interface the signals USB_DP and USB_DM are not defined as GPIO alternative function but as additional function. Additional functions are directly selected/enabled through peripheral registers hand have not to be configured. In this case, the configuration defines GIO_AF_UNDEF as alternative function.
