The esp8266 CPU has actually two hardware UART peripherals. UART0 is
used by the boot ROM for flashing and serial output during boot,
typically at a baudrate of 74880 bps until the bootloader or application
sets the more standard 115200 baudrate. This UART0 device has two
possible pins for TXD, GPIO1 and GPIO2, which are both set to TXD by the
boot ROM. esp8266 modules will typically have GPIO1 labeled as the TX
pin, but it is possible to use GPIO2 for that purpose even while
flashing the device with esptool.py.
The second device, UART1, also has two options for TXD, GPIO2 and GPIO7,
and only one option for RXD, GPIO8. However, GPIO7 and GPIO8 are used
by the flash internally so those options are not very useful unless
maybe while running from IRAM with the flash disabled, for example for
a debugger over UART1.
This patch allows boards to override UART{0,1}_{R,T}XD in their
periph_conf.h to configure the uart selection. Defining UART1_TX will
make the UART_DEV(1) device available.
Tested with:
```CFLAGS='-DUART1_TXD=GPIO2' make -C tests/periph_uart BOARD=esp8266-esp-12x flash term```
* Connected one USB-UART to the standard GPIO1 and GPIO3 for flashing
and console. After flashing we see the manual test output at 115200
bps
* Connected a second USB-UART with RX to GPIO2 running at 74880.
Then run on the first console:
```
> init 1 74880
> send 1 hello
```
The word "hello" appears on the second UART connection.
Note that GPIO2 is used during boot for UART0's TX until the application
or bootloader set it to a regular GPIO, so some boot ROM messages at
74880 bps are visible. After running `init 1 74880` it is set to UART1's
TX.
The RTT overflow callback is not available on all RTT implementations.
This means it is either a no-op or `rtt_set_overflow_cb()` is a no-op
or it will overwrite the alarm set with `rtt_set_alarm()`.
This adds a feature to indicate that proper overflow reporting is available.
This allows to use the sam0 RTT together with the rtt_rtc module.
The idea is to use RTT as a monotonic counter, but still keep track
of the time with the virtual RTC module.
In I2C, clock stretching occurs when the controller stops driving SCL
down but the peripheral continues to drive SCL down until the value of
SDA that is expected to be set by the peripheral is ready. This allows a
peripheral to communicate at a high speed but introduce a delay in the
response (like an ACK or read) in some specific situations. Not all I2C
peripherals require I2C stretching, and in many cases SCL is only an
input to these peripherals.
Clock stretching is the only situation where a peripheral may drive down
SCL, which technically makes SCL an open-drain with a pull-up like SDA.
However, if clock stretching is not needed, SCL can be configured as an
output removing the need for a pull-up and specially, allowing to use
as SCL GPIO pins that otherwise have a pull-down connected. In
particular, GPIO15 in the ESP8266 requires an external pull-down during
boot for the ESP8266 to boot from the flash.
This patch allows a board to define `I2C_CLOCK_STRETCH` to 0 to disable
clock stretching and allowing to use GPIO15 as SCL.
If we configure TAMPCTRL early, GPIO events will set bits in the
TAMPCTRL register.
That means that after a wake-up, we can't tell if the bit was set
because it was the wake-up source or if it was already set by a
run-time GPIO event.
The extra `)` was a typo from the commit that changes the makefile
inline "if" to a multi-line "if" block.
Tested with `USEMODULE="esp_gdbstub" make BOARD=esp8266-esp-12x -C tests/lwip`
The current xmega don't have a way to disable peripherals that are
not in used. Add peripheral management to allow enable only the mcu
blocks that will be used by application. This saves power on active
and sleep modes. By default, at clock initialization, all peripherals
are now disabled and each drive must activate at initialization phase.
The periph_timer and periph_uart were updated with this new feature.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The current ATxmega clock_init enable DFLL to improve the accuracy of
the 2MHz and 32MHz internal oscillators. In some ATxmega revisions,
after started DFLL the clock become unstable. Add another sync point
for 32MHz internal oscilator.
Note: If clock is not stable, system won't switch from 2MHz to 32MHz
as main clock.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Fix compilation with module `stm32_eth_link_up` when `stm32_eth_auto`
is not used by relying on the compiler to optimize unused functions
and variables out, rather than using the preprocessor.
- Clear the PTP timer interrupt *after* the user callback is executed
- Otherwise it would be possible that the ISR sets another super
short timeout that triggers during ISR, which also gets cleared
- This is a pretty nasty race condition :-/
- The debug output was a bit too verbose to be generally useful. Some
noise is now silenced unless `DEBUG_VERBOSE` is `#define`d to 1
Atmel AVR-8 CPU was reworked to accomodate variants like ATxmega.
This rename to atmega.inc.mk to avr8.inc.mk to be compliant with
new directory structure.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
ATxmega have many clock options. This introduce clk_init into cpu_init
to allow user select between a default configuration or perform fine
clock tune.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The XMEGA CPU have a Programmable Multilevel Interrupt Controller.
This enables all three PMIC levels. By default, all interrupts are
preconfigured as LOW Level without Round Robin queue. This works
as any MCU with interrupt enabled.
In order to get benefit from Multilevel Interrupts user need increase
the interrupt level by own.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Current there is no way to split code between ATmega and ATxmega in
drivers. This differentiate AVR8 cores into MEGAs and XMEGAs.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The current context switch and thread stack init don't have a generic
way to save/restore registers for all AVR-8 variations. This add
defines to check flash/data sizes and rework:
- thread_stack_init
- avr8_context_save
- avr8_context_restore
The new implementation add missing RAMP D/X/Y registers that are used
by XMEGA variations.
The rules to add EIND, RAMP(D,X,Y,Z) register are:
- EIND must be added if device have more than 128k flash. This means,
device can access more than 64k words in flash.
- RAMP D/X/Y must be added if device have or can address more than
64k data.
- RAMPZ must be added if device can address more than 64k bytes of
flash or data.
With above rules there is no necessity to check by device because it is
mandatory the registers for those MCU variations.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Add ATxmega common files and cpu definitions.
This works was originally developed by @Josar. The 2018 version
were port to 2021 mainline.
This version changes original port to have only the atxmega CPU
definition. With that, all family can be accomodated.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Some mega boards enabling global irq at board_init. This moves that
responsability to cpu/avr8_common to create a common point to all
variants.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The ATxmega can have up to 8 UARTs. This increase from 2 up to 7 to
keep avr8_state flags with 8 bits wide.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Some periph_rtt implementations do not provide `rtt_set_counter()`. This
adds `periph_rtt_set_counter` as feature to allow testing for its
availability. The feature is provided at CPU level if periph_rtt is
provided by the board for all CPUs implementing `rtt_set_counter()`.
Some periph_rtt implementations do not provide `rtt_set_counter()`. This
adds `periph_rtt_set_counter` as feature to allow testing for its
availability. The feature is provided at CPU level if periph_rtt is
provided by the board for all CPUs implementing `rtt_set_counter()`.
